Reference Meziantou.Analyzer globally and address the existing warnings

.editorconfig

@@ -95,10 +95,22 @@ csharp_using_directive_placement = outside_namespace
 
 [*.{cs,vb}]
 dotnet_code_quality_unused_parameters = all
-dotnet_diagnostic.CA1510.severity = suggestion
+dotnet_diagnostic.CA1510.severity = none
+dotnet_diagnostic.CA1873.severity = none
 dotnet_diagnostic.CA2254.severity = none
 dotnet_diagnostic.IDE0002.severity = none
+dotnet_diagnostic.IDE0042.severity = none
 dotnet_diagnostic.IDE0305.severity = none
+dotnet_diagnostic.MA0003.severity = none
+dotnet_diagnostic.MA0004.severity = none
+dotnet_diagnostic.MA0007.severity = none
+dotnet_diagnostic.MA0016.severity = none
+dotnet_diagnostic.MA0029.severity = none
+dotnet_diagnostic.MA0048.severity = none
+dotnet_diagnostic.MA0051.severity = none
+dotnet_diagnostic.MA0056.severity = none
+dotnet_diagnostic.MA0084.severity = none
+dotnet_diagnostic.MA0100.severity = none
 dotnet_naming_rule.interface_should_be_begins_with_i.severity = suggestion
 dotnet_naming_rule.interface_should_be_begins_with_i.style = begins_with_i
 dotnet_naming_rule.interface_should_be_begins_with_i.symbols = interface

Directory.Packages.props

@@ -4,17 +4,14 @@
     Note: to cover as many platforms as possible and reduce the number of package references,
     OpenIddict extensively uses multi-targeting and per-framework package references. As such,
     package versions must be carefully chosen to ensure they are consistent and compatible with
-    the TFMs supported by OpenIddict (e.g for .NET 10, only Microsoft.AspNetCore.* packages within
+    the TFMs supported by OpenIddict (e.g for .NET 10, only Microsoft.Extensions.* packages within
     the [10.0.0,11.0.0) range are allowed). Special care must also be taken when selecting versions
     to ensure that transitive references also respect the same constraints (e.g for the .NET 10 TFM,
     a package must only depend on Microsoft.Extensions.* packages within the [10.0.0,11.0.0) range).
   -->
 
-  <!--
-    Note: OpenIddict uses Meziantou.Polyfill to dynamically generate polyfills for types that are not available
-    on some of the targeted TFMs (e.g Index, Range or nullable attributes on .NET Framework/.NET Standard).
-  -->
   <ItemGroup Label="Package versions for all targets">
+    <GlobalPackageReference Include="Meziantou.Analyzer"                            Version="3.0.136"         />
     <GlobalPackageReference Include="Meziantou.Polyfill"                            Version="1.0.158"         />
   </ItemGroup>
 

gen/OpenIddict.Client.WebIntegration.Generators/OpenIddictClientWebIntegrationGenerator.cs

@@ -897,7 +897,7 @@ public static partial class OpenIddictClientWebIntegrationConstants
                                 Name = (string) constant.Attribute("Name"),
                                 Value = (string) constant.Attribute("Value")
                             })
-                            .GroupBy(static constant => constant.Class)
+                            .GroupBy(static constant => constant.Class, StringComparer.Ordinal)
                             .ToList(),
                     })
                     .ToList()
@@ -1600,7 +1600,7 @@ public sealed partial class OpenIddictClientWebIntegrationSettings
 
         static TemplateContext CreateTemplateContext(object model)
         {
-            var context = new TemplateContext
+            var context = new TemplateContext(StringComparer.OrdinalIgnoreCase)
             {
                 LimitToString = 128 * 1024 * 1024,
                 LoopLimit = 100_000

sandbox/OpenIddict.Sandbox.AspNet.Client/Controllers/AuthenticationController.cs

@@ -31,7 +31,7 @@ public class AuthenticationController : Controller
         // the user is directly redirected to GitHub (in this case, no login page is shown).
         if (string.Equals(provider, "Local+GitHub", StringComparison.Ordinal))
         {
-            var properties = new AuthenticationProperties(new Dictionary<string, string?>
+            var properties = new AuthenticationProperties(new Dictionary<string, string?>(StringComparer.Ordinal)
             {
                 // Note: when only one client is registered in the client options,
                 // specifying the issuer URI or the provider name is not required.
@@ -61,7 +61,7 @@ public class AuthenticationController : Controller
                 return new HttpStatusCodeResult(400);
             }
 
-            var properties = new AuthenticationProperties(new Dictionary<string, string?>
+            var properties = new AuthenticationProperties(new Dictionary<string, string?>(StringComparer.Ordinal)
             {
                 // Note: when only one client is registered in the client options,
                 // specifying the issuer URI or the provider name is not required.
@@ -100,7 +100,7 @@ public class AuthenticationController : Controller
         if (identity.FindFirst(Claims.Private.RegistrationId)?.Value is string identifier &&
             await _service.GetServerConfigurationByRegistrationIdAsync(identifier) is { EndSessionEndpoint: Uri })
         {
-            var properties = new AuthenticationProperties(new Dictionary<string, string?>
+            var properties = new AuthenticationProperties(new Dictionary<string, string?>(StringComparer.Ordinal)
             {
                 [OpenIddictClientOwinConstants.Properties.RegistrationId] = identifier,
 
@@ -195,7 +195,7 @@ public class AuthenticationController : Controller
                 OpenIddictClientOwinConstants.Tokens.BackchannelAccessToken   or
                 OpenIddictClientOwinConstants.Tokens.BackchannelIdentityToken or
                 OpenIddictClientOwinConstants.Tokens.RefreshToken)
-            .ToDictionary(pair => pair.Key, pair => pair.Value))
+            .ToDictionary(pair => pair.Key, pair => pair.Value, StringComparer.Ordinal))
         {
             // Set the creation and expiration dates of the ticket to null to decorrelate the lifetime
             // of the resulting authentication cookie from the lifetime of the identity token returned by

sandbox/OpenIddict.Sandbox.AspNet.Server/Controllers/AuthenticationController.cs

@@ -86,7 +86,7 @@ public class AuthenticationController : Controller
                 // If needed, the tokens returned by the authorization server can be stored in the authentication cookie.
                 OpenIddictClientOwinConstants.Tokens.BackchannelAccessToken or
                 OpenIddictClientOwinConstants.Tokens.RefreshToken)
-            .ToDictionary(pair => pair.Key, pair => pair.Value))
+            .ToDictionary(pair => pair.Key, pair => pair.Value, StringComparer.Ordinal))
         {
             // Set the creation and expiration dates of the ticket to null to decorrelate the lifetime
             // of the resulting authentication cookie from the lifetime of the identity token returned by

sandbox/OpenIddict.Sandbox.AspNet.Server/Controllers/AuthorizationController.cs

@@ -92,7 +92,7 @@ public class AuthorizationController : Controller
                 {
                     context.Authentication.Challenge(
                         authenticationTypes: OpenIddictServerOwinDefaults.AuthenticationType,
-                        properties: new AuthenticationProperties(new Dictionary<string, string?>
+                        properties: new AuthenticationProperties(new Dictionary<string, string?>(StringComparer.Ordinal)
                         {
                             [OpenIddictServerOwinConstants.Properties.Error] = Errors.InvalidRequest,
                             [OpenIddictServerOwinConstants.Properties.ErrorDescription] =
@@ -102,7 +102,7 @@ public class AuthorizationController : Controller
                     return new EmptyResult();
                 }
 
-                var properties = new AuthenticationProperties(new Dictionary<string, string?>
+                var properties = new AuthenticationProperties(new Dictionary<string, string?>(StringComparer.Ordinal)
                 {
                     // Note: when only one client is registered in the client options,
                     // specifying the issuer URI or the provider name is not required.
@@ -154,7 +154,7 @@ public class AuthorizationController : Controller
             case ConsentTypes.External when authorizations.Count is 0:
                 context.Authentication.Challenge(
                     authenticationTypes: OpenIddictServerOwinDefaults.AuthenticationType,
-                    properties: new AuthenticationProperties(new Dictionary<string, string?>
+                    properties: new AuthenticationProperties(new Dictionary<string, string?>(StringComparer.Ordinal)
                     {
                         [OpenIddictServerOwinConstants.Properties.Error] = Errors.ConsentRequired,
                         [OpenIddictServerOwinConstants.Properties.ErrorDescription] =
@@ -231,7 +231,7 @@ public class AuthorizationController : Controller
             case ConsentTypes.Systematic when request.HasPromptValue(PromptValues.None):
                 context.Authentication.Challenge(
                     authenticationTypes: OpenIddictServerOwinDefaults.AuthenticationType,
-                    properties: new AuthenticationProperties(new Dictionary<string, string?>
+                    properties: new AuthenticationProperties(new Dictionary<string, string?>(StringComparer.Ordinal)
                     {
                         [OpenIddictServerOwinConstants.Properties.Error] = Errors.ConsentRequired,
                         [OpenIddictServerOwinConstants.Properties.ErrorDescription] =
@@ -277,7 +277,7 @@ public class AuthorizationController : Controller
         {
             context.Authentication.Challenge(
                 authenticationTypes: OpenIddictServerOwinDefaults.AuthenticationType,
-                properties: new AuthenticationProperties(new Dictionary<string, string?>
+                properties: new AuthenticationProperties(new Dictionary<string, string?>(StringComparer.Ordinal)
                 {
                     [OpenIddictServerOwinConstants.Properties.Error] = Errors.LoginRequired,
                     [OpenIddictServerOwinConstants.Properties.ErrorDescription] =
@@ -307,7 +307,7 @@ public class AuthorizationController : Controller
         {
             context.Authentication.Challenge(
                 authenticationTypes: OpenIddictServerOwinDefaults.AuthenticationType,
-                properties: new AuthenticationProperties(new Dictionary<string, string?>
+                properties: new AuthenticationProperties(new Dictionary<string, string?>(StringComparer.Ordinal)
                 {
                     [OpenIddictServerOwinConstants.Properties.Error] = Errors.ConsentRequired,
                     [OpenIddictServerOwinConstants.Properties.ErrorDescription] =
@@ -425,7 +425,7 @@ public class AuthorizationController : Controller
             {
                 context.Authentication.Challenge(
                     authenticationTypes: OpenIddictServerOwinDefaults.AuthenticationType,
-                    properties: new AuthenticationProperties(new Dictionary<string, string?>
+                    properties: new AuthenticationProperties(new Dictionary<string, string?>(StringComparer.Ordinal)
                     {
                         [OpenIddictServerOwinConstants.Properties.Error] = Errors.InvalidGrant,
                         [OpenIddictServerOwinConstants.Properties.ErrorDescription] = "The token is no longer valid."
@@ -439,7 +439,7 @@ public class AuthorizationController : Controller
             {
                 context.Authentication.Challenge(
                     authenticationTypes: OpenIddictServerOwinDefaults.AuthenticationType,
-                    properties: new AuthenticationProperties(new Dictionary<string, string?>
+                    properties: new AuthenticationProperties(new Dictionary<string, string?>(StringComparer.Ordinal)
                     {
                         [OpenIddictServerOwinConstants.Properties.Error] = Errors.InvalidGrant,
                         [OpenIddictServerOwinConstants.Properties.ErrorDescription] = "The user is no longer allowed to sign in."

sandbox/OpenIddict.Sandbox.AspNet.Server/Controllers/ManageController.cs

@@ -289,7 +289,7 @@ public class ManageController : Controller
             return View("Error");
         }
         var userLogins = await UserManager.GetLoginsAsync(User.Identity.GetUserId());
-        var otherLogins = AuthenticationManager.GetExternalAuthenticationTypes().Where(auth => userLogins.All(ul => auth.AuthenticationType != ul.LoginProvider)).ToList();
+        var otherLogins = AuthenticationManager.GetExternalAuthenticationTypes().Where(auth => userLogins.All(ul => !string.Equals(auth.AuthenticationType, ul.LoginProvider, System.StringComparison.Ordinal))).ToList();
         ViewBag.ShowRemoveButton = user.PasswordHash != null || userLogins.Count > 1;
         return View(new ManageLoginsViewModel
         {

sandbox/OpenIddict.Sandbox.AspNet.Server/Controllers/ResourceController.cs

@@ -1,4 +1,5 @@
-using System.Collections.Generic;
+using System;
+using System.Collections.Generic;
 using System.Net;
 using System.Net.Http;
 using System.Security.Claims;
@@ -27,7 +28,7 @@ public class ResourceController : ApiController
         {
             context.Authentication.Challenge(
                 authenticationTypes: OpenIddictValidationOwinDefaults.AuthenticationType,
-                properties: new AuthenticationProperties(new Dictionary<string, string?>
+                properties: new AuthenticationProperties(new Dictionary<string, string?>(StringComparer.Ordinal)
                 {
                     [OpenIddictValidationOwinConstants.Properties.Scope] = "demo_api",
                     [OpenIddictValidationOwinConstants.Properties.Error] = Errors.InsufficientScope,
@@ -43,7 +44,7 @@ public class ResourceController : ApiController
         {
             context.Authentication.Challenge(
                 authenticationTypes: OpenIddictValidationOwinDefaults.AuthenticationType,
-                properties: new AuthenticationProperties(new Dictionary<string, string?>
+                properties: new AuthenticationProperties(new Dictionary<string, string?>(StringComparer.Ordinal)
                 {
                     [OpenIddictValidationOwinConstants.Properties.Error] = Errors.InvalidToken,
                     [OpenIddictValidationOwinConstants.Properties.ErrorDescription] =

sandbox/OpenIddict.Sandbox.AspNetCore.Client/Controllers/AuthenticationController.cs

@@ -24,7 +24,7 @@ public class AuthenticationController : Controller
         // the user is directly redirected to GitHub (in this case, no login page is shown).
         if (string.Equals(provider, "Local+GitHub", StringComparison.Ordinal))
         {
-            var properties = new AuthenticationProperties(new Dictionary<string, string?>
+            var properties = new AuthenticationProperties(new Dictionary<string, string?>(StringComparer.Ordinal)
             {
                 // Note: when only one client is registered in the client options,
                 // specifying the issuer URI or the provider name is not required.
@@ -54,7 +54,7 @@ public class AuthenticationController : Controller
                 return BadRequest();
             }
 
-            var properties = new AuthenticationProperties(new Dictionary<string, string?>
+            var properties = new AuthenticationProperties(new Dictionary<string, string?>(StringComparer.Ordinal)
             {
                 // Note: when only one client is registered in the client options,
                 // specifying the issuer URI or the provider name is not required.
@@ -96,7 +96,7 @@ public class AuthenticationController : Controller
         if (identity.FindFirst(Claims.Private.RegistrationId)?.Value is string identifier &&
             await _service.GetServerConfigurationByRegistrationIdAsync(identifier) is { EndSessionEndpoint: Uri })
         {
-            var properties = new AuthenticationProperties(new Dictionary<string, string?>
+            var properties = new AuthenticationProperties(new Dictionary<string, string?>(StringComparer.Ordinal)
             {
                 [OpenIddictClientAspNetCoreConstants.Properties.RegistrationId] = identifier,
 

sandbox/OpenIddict.Sandbox.AspNetCore.Server/Controllers/AccountController.cs

@@ -71,11 +71,9 @@ public class AccountController : Controller
             {
                 return View("Lockout");
             }
-            else
-            {
-                ModelState.AddModelError(string.Empty, "Invalid login attempt.");
-                return View(model);
-            }
+
+            ModelState.AddModelError(string.Empty, "Invalid login attempt.");
+            return View(model);
         }
 
         // If we got this far, something failed, redisplay form
@@ -173,14 +171,12 @@ public class AccountController : Controller
         {
             return View("Lockout");
         }
-        else
-        {
-            // If the user does not have an account, then ask the user to create an account.
-            ViewData["ReturnUrl"] = returnUrl;
-            ViewData["LoginProvider"] = info.LoginProvider;
-            var email = info.Principal.FindFirstValue(ClaimTypes.Email);
-            return View("ExternalLoginConfirmation", new ExternalLoginConfirmationViewModel { Email = email });
-        }
+
+        // If the user does not have an account, then ask the user to create an account.
+        ViewData["ReturnUrl"] = returnUrl;
+        ViewData["LoginProvider"] = info.LoginProvider;
+        var email = info.Principal.FindFirstValue(ClaimTypes.Email);
+        return View("ExternalLoginConfirmation", new ExternalLoginConfirmationViewModel { Email = email });
     }
 
     //
@@ -367,11 +363,11 @@ public class AccountController : Controller
         }
 
         var message = "Your security code is: " + code;
-        if (model.SelectedProvider == "Email")
+        if (string.Equals(model.SelectedProvider, "Email", StringComparison.Ordinal))
         {
             await _emailSender.SendEmailAsync(await _userManager.GetEmailAsync(user), "Security Code", message);
         }
-        else if (model.SelectedProvider == "Phone")
+        else if (string.Equals(model.SelectedProvider, "Phone", StringComparison.Ordinal))
         {
             await _smsSender.SendSmsAsync(await _userManager.GetPhoneNumberAsync(user), message);
         }
@@ -418,11 +414,9 @@ public class AccountController : Controller
         {
             return View("Lockout");
         }
-        else
-        {
-            ModelState.AddModelError("", "Invalid code.");
-            return View(model);
-        }
+
+        ModelState.AddModelError("", "Invalid code.");
+        return View(model);
     }
 
     #region Helpers
@@ -460,10 +454,8 @@ public class AccountController : Controller
         {
             return Redirect(returnUrl);
         }
-        else
-        {
-            return RedirectToAction(nameof(HomeController.Index), "Home");
-        }
+
+        return RedirectToAction(nameof(HomeController.Index), "Home");
     }
 
     #endregion

sandbox/OpenIddict.Sandbox.AspNetCore.Server/Controllers/AuthorizationController.cs

@@ -4,6 +4,7 @@
  * the license and the contributors participating to this project.
  */
 
+using System.Globalization;
 using System.Security.Claims;
 using System.Text.Json.Nodes;
 using Microsoft.AspNetCore;
@@ -91,7 +92,7 @@ public class AuthorizationController : Controller
             {
                 return Forbid(
                     authenticationSchemes: OpenIddictServerAspNetCoreDefaults.AuthenticationScheme,
-                    properties: new AuthenticationProperties(new Dictionary<string, string?>
+                    properties: new AuthenticationProperties(new Dictionary<string, string?>(StringComparer.Ordinal)
                     {
                         [OpenIddictServerAspNetCoreConstants.Properties.Error] = Errors.LoginRequired,
                         [OpenIddictServerAspNetCoreConstants.Properties.ErrorDescription] = "The user is not logged in."
@@ -117,7 +118,7 @@ public class AuthorizationController : Controller
                 {
                     return Forbid(
                         authenticationSchemes: OpenIddictServerAspNetCoreDefaults.AuthenticationScheme,
-                        properties: new AuthenticationProperties(new Dictionary<string, string?>
+                        properties: new AuthenticationProperties(new Dictionary<string, string?>(StringComparer.Ordinal)
                         {
                             [OpenIddictServerAspNetCoreConstants.Properties.Error] = Errors.InvalidRequest,
                             [OpenIddictServerAspNetCoreConstants.Properties.ErrorDescription] =
@@ -181,7 +182,7 @@ public class AuthorizationController : Controller
             case ConsentTypes.External when authorizations.Count is 0:
                 return Forbid(
                     authenticationSchemes: OpenIddictServerAspNetCoreDefaults.AuthenticationScheme,
-                    properties: new AuthenticationProperties(new Dictionary<string, string?>
+                    properties: new AuthenticationProperties(new Dictionary<string, string?>(StringComparer.Ordinal)
                     {
                         [OpenIddictServerAspNetCoreConstants.Properties.Error] = Errors.ConsentRequired,
                         [OpenIddictServerAspNetCoreConstants.Properties.ErrorDescription] =
@@ -255,7 +256,7 @@ public class AuthorizationController : Controller
             case ConsentTypes.Systematic when request.HasPromptValue(PromptValues.None):
                 return Forbid(
                     authenticationSchemes: OpenIddictServerAspNetCoreDefaults.AuthenticationScheme,
-                    properties: new AuthenticationProperties(new Dictionary<string, string?>
+                    properties: new AuthenticationProperties(new Dictionary<string, string?>(StringComparer.Ordinal)
                     {
                         [OpenIddictServerAspNetCoreConstants.Properties.Error] = Errors.ConsentRequired,
                         [OpenIddictServerAspNetCoreConstants.Properties.ErrorDescription] =
@@ -265,7 +266,7 @@ public class AuthorizationController : Controller
             // In every other case, render the consent form.
             default: return View(new AuthorizeViewModel
             {
-                ApplicationName = await _applicationManager.GetLocalizedDisplayNameAsync(application),
+                ApplicationName = await _applicationManager.GetLocalizedDisplayNameAsync(application, CultureInfo.CurrentCulture),
                 Scope = request.Scope
             });
         }
@@ -289,7 +290,7 @@ public class AuthorizationController : Controller
         {
             return Forbid(
                 authenticationSchemes: OpenIddictServerAspNetCoreDefaults.AuthenticationScheme,
-                properties: new AuthenticationProperties(new Dictionary<string, string?>
+                properties: new AuthenticationProperties(new Dictionary<string, string?>(StringComparer.Ordinal)
                 {
                     [OpenIddictServerAspNetCoreConstants.Properties.Error] = Errors.LoginRequired,
                     [OpenIddictServerAspNetCoreConstants.Properties.ErrorDescription] =
@@ -317,7 +318,7 @@ public class AuthorizationController : Controller
         {
             return Forbid(
                 authenticationSchemes: OpenIddictServerAspNetCoreDefaults.AuthenticationScheme,
-                properties: new AuthenticationProperties(new Dictionary<string, string?>
+                properties: new AuthenticationProperties(new Dictionary<string, string?>(StringComparer.Ordinal)
                 {
                     [OpenIddictServerAspNetCoreConstants.Properties.Error] = Errors.ConsentRequired,
                     [OpenIddictServerAspNetCoreConstants.Properties.ErrorDescription] =
@@ -406,15 +407,13 @@ public class AuthorizationController : Controller
             // Render a form asking the user to confirm the authorization demand.
             return View(new VerifyViewModel
             {
-                ApplicationName = await _applicationManager.GetLocalizedDisplayNameAsync(application),
-                Scope = string.Join(" ", result.Principal.GetScopes()),
+                ApplicationName = await _applicationManager.GetLocalizedDisplayNameAsync(application, CultureInfo.CurrentCulture),
+                Scope = string.Join(Separators.Space[0], result.Principal.GetScopes()),
                 UserCode = result.Properties.GetTokenValue(OpenIddictServerAspNetCoreConstants.Tokens.UserCode)
             });
         }
 
-        // If a user code was specified (e.g as part of the verification_uri_complete)
-        // but is not valid, render a form asking the user to enter the user code manually.
-        else if (!string.IsNullOrEmpty(result.Properties?.GetTokenValue(OpenIddictServerAspNetCoreConstants.Tokens.UserCode)))
+        if (!string.IsNullOrEmpty(result.Properties?.GetTokenValue(OpenIddictServerAspNetCoreConstants.Tokens.UserCode)))
         {
             return View(new VerifyViewModel
             {
@@ -437,7 +436,7 @@ public class AuthorizationController : Controller
         {
             return Forbid(
                 authenticationSchemes: OpenIddictServerAspNetCoreDefaults.AuthenticationScheme,
-                properties: new AuthenticationProperties(new Dictionary<string, string?>
+                properties: new AuthenticationProperties(new Dictionary<string, string?>(StringComparer.Ordinal)
                 {
                     [OpenIddictServerAspNetCoreConstants.Properties.Error] = Errors.LoginRequired,
                     [OpenIddictServerAspNetCoreConstants.Properties.ErrorDescription] =
@@ -544,7 +543,7 @@ public class AuthorizationController : Controller
             {
                 return Forbid(
                     authenticationSchemes: OpenIddictServerAspNetCoreDefaults.AuthenticationScheme,
-                    properties: new AuthenticationProperties(new Dictionary<string, string?>
+                    properties: new AuthenticationProperties(new Dictionary<string, string?>(StringComparer.Ordinal)
                     {
                         [OpenIddictServerAspNetCoreConstants.Properties.Error] = Errors.InvalidGrant,
                         [OpenIddictServerAspNetCoreConstants.Properties.ErrorDescription] = "The username/password couple is invalid."
@@ -557,7 +556,7 @@ public class AuthorizationController : Controller
             {
                 return Forbid(
                     authenticationSchemes: OpenIddictServerAspNetCoreDefaults.AuthenticationScheme,
-                    properties: new AuthenticationProperties(new Dictionary<string, string?>
+                    properties: new AuthenticationProperties(new Dictionary<string, string?>(StringComparer.Ordinal)
                     {
                         [OpenIddictServerAspNetCoreConstants.Properties.Error] = Errors.InvalidGrant,
                         [OpenIddictServerAspNetCoreConstants.Properties.ErrorDescription] = "The username/password couple is invalid."
@@ -599,7 +598,7 @@ public class AuthorizationController : Controller
             {
                 return Forbid(
                     authenticationSchemes: OpenIddictServerAspNetCoreDefaults.AuthenticationScheme,
-                    properties: new AuthenticationProperties(new Dictionary<string, string?>
+                    properties: new AuthenticationProperties(new Dictionary<string, string?>(StringComparer.Ordinal)
                     {
                         [OpenIddictServerAspNetCoreConstants.Properties.Error] = Errors.InvalidGrant,
                         [OpenIddictServerAspNetCoreConstants.Properties.ErrorDescription] = "The token is no longer valid."
@@ -611,7 +610,7 @@ public class AuthorizationController : Controller
             {
                 return Forbid(
                     authenticationSchemes: OpenIddictServerAspNetCoreDefaults.AuthenticationScheme,
-                    properties: new AuthenticationProperties(new Dictionary<string, string?>
+                    properties: new AuthenticationProperties(new Dictionary<string, string?>(StringComparer.Ordinal)
                     {
                         [OpenIddictServerAspNetCoreConstants.Properties.Error] = Errors.InvalidGrant,
                         [OpenIddictServerAspNetCoreConstants.Properties.ErrorDescription] = "The user is no longer allowed to sign in."
@@ -657,7 +656,7 @@ public class AuthorizationController : Controller
             {
                 return Forbid(
                     authenticationSchemes: OpenIddictServerAspNetCoreDefaults.AuthenticationScheme,
-                    properties: new AuthenticationProperties(new Dictionary<string, string?>
+                    properties: new AuthenticationProperties(new Dictionary<string, string?>(StringComparer.Ordinal)
                     {
                         [OpenIddictServerAspNetCoreConstants.Properties.Error] = Errors.InvalidGrant,
                         [OpenIddictServerAspNetCoreConstants.Properties.ErrorDescription] = "The token is no longer valid."
@@ -669,7 +668,7 @@ public class AuthorizationController : Controller
             {
                 return Forbid(
                     authenticationSchemes: OpenIddictServerAspNetCoreDefaults.AuthenticationScheme,
-                    properties: new AuthenticationProperties(new Dictionary<string, string?>
+                    properties: new AuthenticationProperties(new Dictionary<string, string?>(StringComparer.Ordinal)
                     {
                         [OpenIddictServerAspNetCoreConstants.Properties.Error] = Errors.InvalidGrant,
                         [OpenIddictServerAspNetCoreConstants.Properties.ErrorDescription] = "The user is no longer allowed to sign in."

sandbox/OpenIddict.Sandbox.AspNetCore.Server/Controllers/ManageController.cs

@@ -271,7 +271,7 @@ public class ManageController : Controller
             return View("Error");
         }
         var userLogins = await _userManager.GetLoginsAsync(user);
-        var otherLogins = (await _signInManager.GetExternalAuthenticationSchemesAsync()).Where(auth => userLogins.All(ul => auth.Name != ul.LoginProvider)).ToList();
+        var otherLogins = (await _signInManager.GetExternalAuthenticationSchemesAsync()).Where(auth => userLogins.All(ul => !string.Equals(auth.Name, ul.LoginProvider, StringComparison.Ordinal))).ToList();
         ViewData["ShowRemoveButton"] = user.PasswordHash is not null || userLogins.Count > 1;
         return View(new ManageLoginsViewModel
         {

sandbox/OpenIddict.Sandbox.AspNetCore.Server/Controllers/ResourceController.cs

@@ -28,7 +28,7 @@ public class ResourceController : Controller
         {
             return Forbid(
                 authenticationSchemes: OpenIddictValidationAspNetCoreDefaults.AuthenticationScheme,
-                properties: new AuthenticationProperties(new Dictionary<string, string?>
+                properties: new AuthenticationProperties(new Dictionary<string, string?>(StringComparer.Ordinal)
                 {
                     [OpenIddictValidationAspNetCoreConstants.Properties.Scope] = "demo_api",
                     [OpenIddictValidationAspNetCoreConstants.Properties.Error] = Errors.InsufficientScope,
@@ -42,7 +42,7 @@ public class ResourceController : Controller
         {
             return Challenge(
                 authenticationSchemes: OpenIddictValidationAspNetCoreDefaults.AuthenticationScheme,
-                properties: new AuthenticationProperties(new Dictionary<string, string?>
+                properties: new AuthenticationProperties(new Dictionary<string, string?>(StringComparer.Ordinal)
                 {
                     [OpenIddictValidationAspNetCoreConstants.Properties.Error] = Errors.InvalidToken,
                     [OpenIddictValidationAspNetCoreConstants.Properties.ErrorDescription] =

sandbox/OpenIddict.Sandbox.AspNetCore.Server/Controllers/UserinfoController.cs

@@ -26,7 +26,7 @@ public class UserInfoController : Controller
         {
             return Challenge(
                 authenticationSchemes: OpenIddictServerAspNetCoreDefaults.AuthenticationScheme,
-                properties: new AuthenticationProperties(new Dictionary<string, string?>
+                properties: new AuthenticationProperties(new Dictionary<string, string?>(StringComparer.Ordinal)
                 {
                     [OpenIddictServerAspNetCoreConstants.Properties.Error] = Errors.InvalidToken,
                     [OpenIddictServerAspNetCoreConstants.Properties.ErrorDescription] =

sandbox/OpenIddict.Sandbox.AspNetCore.Server/Program.cs

@@ -370,8 +370,8 @@ builder.Services.Configure<KestrelServerOptions>(options => options.ListenAnyIP(
             ServerCertificate = store.Certificates
                 .Find(X509FindType.FindByExtension, "1.3.6.1.4.1.311.84.1.1", validOnly: false)
                 .Cast<X509Certificate2>()
-                .Where(static certificate => certificate.NotBefore < TimeProvider.System.GetLocalNow())
-                .Where(static certificate => certificate.NotAfter > TimeProvider.System.GetLocalNow())
+                .Where(static certificate => new DateTimeOffset(certificate.NotBefore) < TimeProvider.System.GetLocalNow())
+                .Where(static certificate => new DateTimeOffset(certificate.NotAfter) > TimeProvider.System.GetLocalNow())
                 .OrderByDescending(static certificate => certificate.NotAfter)
                 .FirstOrDefault()
                 ?? throw new InvalidOperationException("The ASP.NET Core HTTPS development certificate was not found.")

sandbox/OpenIddict.Sandbox.Console.Client/InteractiveService.cs

@@ -502,13 +502,13 @@ public class InteractiveService : BackgroundService
                 List<((string? GrantType, string? ResponseType), string DisplayName)> choices = [];
 
                 var types = configuration.ResponseTypesSupported.Select(static type =>
-                    new HashSet<string>(type.Split(Separators.Space, StringSplitOptions.RemoveEmptyEntries)));
+                    new HashSet<string>(type.Split(Separators.Space, StringSplitOptions.RemoveEmptyEntries), StringComparer.Ordinal));
 
                 if (configuration.GrantTypesSupported.Contains(GrantTypes.AuthorizationCode) &&
                     (registration.GrantTypes.Count is 0 || registration.GrantTypes.Contains(GrantTypes.AuthorizationCode)) &&
                     types.Any(static type => type.Count is 1 && type.Contains(ResponseTypes.Code)) &&
                     (registration.ResponseTypes.Count is 0 || registration.ResponseTypes
-                        .Select(static type => new HashSet<string>(type.Split(Separators.Space, StringSplitOptions.RemoveEmptyEntries)))
+                        .Select(static type => new HashSet<string>(type.Split(Separators.Space, StringSplitOptions.RemoveEmptyEntries), StringComparer.Ordinal))
                         .Any(static type => type.Count is 1 && type.Contains(ResponseTypes.Code))))
                 {
                     choices.Add(((
@@ -521,7 +521,7 @@ public class InteractiveService : BackgroundService
                 {
                     if (types.Any(static type => type.Count is 1 && type.Contains(ResponseTypes.IdToken)) &&
                         (registration.ResponseTypes.Count is 0 || registration.ResponseTypes
-                            .Select(static type => new HashSet<string>(type.Split(Separators.Space, StringSplitOptions.RemoveEmptyEntries)))
+                            .Select(static type => new HashSet<string>(type.Split(Separators.Space, StringSplitOptions.RemoveEmptyEntries), StringComparer.Ordinal))
                             .Any(static type => type.Count is 1 && type.Contains(ResponseTypes.IdToken))))
                     {
                         choices.Add(((
@@ -532,7 +532,7 @@ public class InteractiveService : BackgroundService
                     if (types.Any(static type => type.Count is 2 && type.Contains(ResponseTypes.IdToken) &&
                                                                     type.Contains(ResponseTypes.Token)) &&
                         (registration.ResponseTypes.Count is 0 || registration.ResponseTypes
-                            .Select(static type => new HashSet<string>(type.Split(Separators.Space, StringSplitOptions.RemoveEmptyEntries)))
+                            .Select(static type => new HashSet<string>(type.Split(Separators.Space, StringSplitOptions.RemoveEmptyEntries), StringComparer.Ordinal))
                             .Any(static type => type.Count is 2 && type.Contains(ResponseTypes.IdToken) &&
                                                                    type.Contains(ResponseTypes.Token))))
                     {
@@ -550,7 +550,7 @@ public class InteractiveService : BackgroundService
                     if (types.Any(static type => type.Count is 2 && type.Contains(ResponseTypes.Code) &&
                                                                     type.Contains(ResponseTypes.IdToken)) &&
                         (registration.ResponseTypes.Count is 0 || registration.ResponseTypes
-                            .Select(static type => new HashSet<string>(type.Split(Separators.Space, StringSplitOptions.RemoveEmptyEntries)))
+                            .Select(static type => new HashSet<string>(type.Split(Separators.Space, StringSplitOptions.RemoveEmptyEntries), StringComparer.Ordinal))
                             .Any(static type => type.Count is 2 && type.Contains(ResponseTypes.Code) &&
                                                                    type.Contains(ResponseTypes.IdToken))))
                     {
@@ -563,7 +563,7 @@ public class InteractiveService : BackgroundService
                                                              type.Contains(ResponseTypes.IdToken) &&
                                                              type.Contains(ResponseTypes.Token)) &&
                         (registration.ResponseTypes.Count is 0 || registration.ResponseTypes
-                            .Select(static type => new HashSet<string>(type.Split(Separators.Space, StringSplitOptions.RemoveEmptyEntries)))
+                            .Select(static type => new HashSet<string>(type.Split(Separators.Space, StringSplitOptions.RemoveEmptyEntries), StringComparer.Ordinal))
                             .Any(static type => type.Count is 3 && type.Contains(ResponseTypes.Code) &&
                                                                    type.Contains(ResponseTypes.IdToken) &&
                                                                    type.Contains(ResponseTypes.Token))))
@@ -577,7 +577,7 @@ public class InteractiveService : BackgroundService
                     if (types.Any(static type => type.Count is 2 && type.Contains(ResponseTypes.Code) &&
                                                                     type.Contains(ResponseTypes.Token)) &&
                         (registration.ResponseTypes.Count is 0 || registration.ResponseTypes
-                            .Select(static type => new HashSet<string>(type.Split(Separators.Space, StringSplitOptions.RemoveEmptyEntries)))
+                            .Select(static type => new HashSet<string>(type.Split(Separators.Space, StringSplitOptions.RemoveEmptyEntries), StringComparer.Ordinal))
                             .Any(static type => type.Count is 2 && type.Contains(ResponseTypes.Code) &&
                                                                    type.Contains(ResponseTypes.Token))))
                     {
@@ -589,7 +589,7 @@ public class InteractiveService : BackgroundService
 
                 if (types.Any(static type => type.Count is 1 && type.Contains(ResponseTypes.None)) &&
                     (registration.ResponseTypes.Count is 0 || registration.ResponseTypes
-                        .Select(static type => new HashSet<string>(type.Split(Separators.Space, StringSplitOptions.RemoveEmptyEntries)))
+                        .Select(static type => new HashSet<string>(type.Split(Separators.Space, StringSplitOptions.RemoveEmptyEntries), StringComparer.Ordinal))
                         .Any(static type => type.Count is 1 && type.Contains(ResponseTypes.None))))
                 {
                     choices.Add(((
@@ -873,7 +873,9 @@ public class InteractiveService : BackgroundService
             //
             // In a real world application, the certificate wouldn't be embedded in the source code
             // and would be installed in the certificate store, making this workaround unnecessary.
+#pragma warning disable MA0144
             if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
+#pragma warning restore MA0144
             {
                 certificate = X509CertificateLoader.LoadPkcs12(
                     data: certificate.Export(X509ContentType.Pfx, string.Empty),

sandbox/OpenIddict.Sandbox.Maui.Client/MainPage.xaml.cs

@@ -22,7 +22,7 @@ public partial class MainPage : ContentPage
         => await LogInAsync("Local");
 
     private async void OnLocalLoginWithGitHubButtonClicked(object sender, EventArgs e)
-        => await LogInAsync("Local", new()
+        => await LogInAsync("Local", new(StringComparer.Ordinal)
         {
             [Parameters.IdentityProvider] = Providers.GitHub
         });

sandbox/OpenIddict.Sandbox.Maui.Client/MauiProgram.cs

@@ -57,8 +57,10 @@ public static class MauiProgram
 #if IOS
                        // Warning: server certificate validation is disabled to simplify testing the MAUI
                        // application with the iOS simulator: in production, it SHOULD NEVER be disabled.
+#pragma warning disable MA0039
                        .ConfigureHttpClientHandler("Local", handler => handler.ServerCertificateCustomValidationCallback =
                            HttpClientHandler.DangerousAcceptAnyServerCertificateValidator)
+#pragma warning restore MA0039
 #endif
                        ;
 

sandbox/OpenIddict.Sandbox.WinForms.Client/MainForm.cs

@@ -22,7 +22,7 @@ public partial class MainForm : Form, IWinFormsShell
         => await LogInAsync("Local");
 
     private async void LocalLoginWithGitHubButton_Click(object sender, EventArgs e)
-        => await LogInAsync("Local", new()
+        => await LogInAsync("Local", new(StringComparer.Ordinal)
         {
             [Parameters.IdentityProvider] = Providers.GitHub
         });

sandbox/OpenIddict.Sandbox.Wpf.Client/MainWindow.xaml.cs

@@ -23,7 +23,7 @@ public partial class MainWindow : Window, IWpfShell
         => await LogInAsync("Local");
 
     private async void LocalLoginWithGitHubButton_Click(object sender, RoutedEventArgs e)
-        => await LogInAsync("Local", new()
+        => await LogInAsync("Local", new(StringComparer.Ordinal)
         {
             [Parameters.IdentityProvider] = Providers.GitHub
         });

shared/OpenIddict.Extensions/OpenIddictHelpers.cs

@@ -276,8 +276,8 @@ internal static class OpenIddictHelpers
                 Key: parts[0] is string key ? Uri.UnescapeDataString(key) : null,
                 Value: parts.Length is > 1 && parts[1] is string value ? Uri.UnescapeDataString(value) : null))
             .Where(static pair => !string.IsNullOrEmpty(pair.Key))
-            .GroupBy(static pair => pair.Key)
-            .ToDictionary(static pair => pair.Key!, static pair => new StringValues([.. pair.Select(parts => parts.Value)]));
+            .GroupBy(static pair => pair.Key, StringComparer.Ordinal)
+            .ToDictionary(static pair => pair.Key!, static pair => new StringValues([.. pair.Select(parts => parts.Value)]), StringComparer.Ordinal);
     }
 
     /// <summary>
@@ -297,8 +297,8 @@ internal static class OpenIddictHelpers
                 Key: parts[0] is string key ? Uri.UnescapeDataString(key) : null,
                 Value: parts.Length is > 1 && parts[1] is string value ? Uri.UnescapeDataString(value) : null))
             .Where(static pair => !string.IsNullOrEmpty(pair.Key))
-            .GroupBy(static pair => pair.Key)
-            .ToDictionary(static pair => pair.Key!, static pair => new StringValues([.. pair.Select(parts => parts.Value)]));
+            .GroupBy(static pair => pair.Key, StringComparer.Ordinal)
+            .ToDictionary(static pair => pair.Key!, static pair => new StringValues([.. pair.Select(parts => parts.Value)]), StringComparer.Ordinal);
     }
 
     /// <summary>
@@ -345,7 +345,7 @@ internal static class OpenIddictHelpers
         while (enumerator.MoveNext())
         {
             var element = enumerator.GetTextElement();
-            if (charset.Contains(element))
+            if (charset.Contains(element, StringComparer.Ordinal))
             {
                 builder.Append(element);
             }

src/OpenIddict.Abstractions/OpenIddictConstants.cs

@@ -560,6 +560,7 @@ public static class OpenIddictConstants
         public static readonly char[] DoubleQuote = ['"'];
         public static readonly char[] EqualsSign = ['='];
         public static readonly char[] Hash = ['#'];
+        public static readonly char[] Plus = ['+'];
         public static readonly char[] QuestionMark = ['?'];
         public static readonly char[] Semicolon = [';'];
         public static readonly char[] Space = [' '];

src/OpenIddict.Abstractions/Primitives/OpenIddictExtensions.cs

@@ -308,9 +308,7 @@ public static class OpenIddictExtensions
                 continue;
             }
 
-            // Note: though the OIDC core specs does not include the OAuth 2.0-inherited response_type=token,
-            // it is considered as a valid response_type for the implicit flow for backward compatibility.
-            else if (segment.Equals(ResponseTypes.Token, StringComparison.Ordinal))
+            if (segment.Equals(ResponseTypes.Token, StringComparison.Ordinal))
             {
                 flags |= /* token */ 0x02;
 
@@ -359,14 +357,14 @@ public static class OpenIddictExtensions
                 continue;
             }
 
-            else if (segment.Equals(ResponseTypes.IdToken, StringComparison.Ordinal))
+            if (segment.Equals(ResponseTypes.IdToken, StringComparison.Ordinal))
             {
                 flags |= /* id_token: */ 0x02;
 
                 continue;
             }
 
-            else if (segment.Equals(ResponseTypes.Token, StringComparison.Ordinal))
+            if (segment.Equals(ResponseTypes.Token, StringComparison.Ordinal))
             {
                 flags |= /* token: */ 0x04;
 
@@ -678,7 +676,7 @@ public static class OpenIddictExtensions
 
         var builder = ImmutableDictionary.CreateBuilder<string, ImmutableArray<string>>(StringComparer.Ordinal);
 
-        foreach (var group in identity.Claims.GroupBy(claim => claim.Type))
+        foreach (var group in identity.Claims.GroupBy(claim => claim.Type, StringComparer.Ordinal))
         {
             var claims = group.ToList();
 
@@ -712,7 +710,7 @@ public static class OpenIddictExtensions
 
         var builder = ImmutableDictionary.CreateBuilder<string, ImmutableArray<string>>(StringComparer.Ordinal);
 
-        foreach (var group in principal.Claims.GroupBy(claim => claim.Type))
+        foreach (var group in principal.Claims.GroupBy(claim => claim.Type, StringComparer.Ordinal))
         {
             var claims = group.ToList();
 
@@ -749,7 +747,8 @@ public static class OpenIddictExtensions
 
         foreach (var destination in destinations)
         {
-            foreach (var claim in identity.Claims.Where(claim => claim.Type == destination.Key))
+            foreach (var claim in identity.Claims.Where(claim =>
+                string.Equals(claim.Type, destination.Key, StringComparison.Ordinal)))
             {
                 claim.SetDestinations(destination.Value);
             }
@@ -772,7 +771,8 @@ public static class OpenIddictExtensions
 
         foreach (var destination in destinations)
         {
-            foreach (var claim in principal.Claims.Where(claim => claim.Type == destination.Key))
+            foreach (var claim in principal.Claims.Where(claim =>
+                string.Equals(claim.Type, destination.Key, StringComparison.Ordinal)))
             {
                 claim.SetDestinations(destination.Value);
             }

src/OpenIddict.Abstractions/Primitives/OpenIddictMessage.cs

@@ -121,7 +121,7 @@ public class OpenIddictMessage
     {
         ArgumentNullException.ThrowIfNull(parameters);
 
-        foreach (var parameter in parameters.GroupBy(parameter => parameter.Key))
+        foreach (var parameter in parameters.GroupBy(parameter => parameter.Key, StringComparer.Ordinal))
         {
             // Ignore parameters whose name is null or empty.
             if (string.IsNullOrEmpty(parameter.Key))

src/OpenIddict.Abstractions/Primitives/OpenIddictParameter.cs

@@ -205,7 +205,7 @@ public readonly struct OpenIddictParameter : IEquatable<OpenIddictParameter>
             (string left, string right) => string.Equals(left, right, StringComparison.Ordinal),
 
             // If the two parameters are string arrays, use SequenceEqual().
-            (string?[] left, string?[] right) => Enumerable.SequenceEqual(left, right),
+            (string?[] left, string?[] right) => Enumerable.SequenceEqual(left, right, StringComparer.Ordinal),
 
             // If one of the two parameters is an undefined JsonElement, treat it
             // as a null value and return true if the other parameter is null too.
@@ -323,7 +323,7 @@ public readonly struct OpenIddictParameter : IEquatable<OpenIddictParameter>
             JsonValue value when value.TryGetValue(out int  result) => result.GetHashCode(),
             JsonValue value when value.TryGetValue(out long result) => result.GetHashCode(),
 
-            JsonValue value when value.TryGetValue(out string? result) => result.GetHashCode(),
+            JsonValue value when value.TryGetValue(out string? result) => result.GetHashCode(StringComparison.Ordinal),
 
             // When the parameter is a JsonNode (e.g a JsonValue wrapping a non-primitive type),
             // serialize it to a JsonElement first to determine its actual JSON representation
@@ -342,7 +342,7 @@ public readonly struct OpenIddictParameter : IEquatable<OpenIddictParameter>
 
             for (var index = 0; index < array.Length; index++)
             {
-                hash.Add(array[index]);
+                hash.Add(array[index], StringComparer.Ordinal);
             }
 
             return hash.ToHashCode();
@@ -368,10 +368,10 @@ public readonly struct OpenIddictParameter : IEquatable<OpenIddictParameter>
                     return result.GetHashCode();
 
                 case JsonValueKind.Number:
-                    return element.GetRawText().GetHashCode();
+                    return element.GetRawText().GetHashCode(StringComparison.Ordinal);
 
                 case JsonValueKind.String:
-                    return element.GetString()!.GetHashCode();
+                    return element.GetString()!.GetHashCode(StringComparison.Ordinal);
 
                 case JsonValueKind.Array:
                 {
@@ -391,7 +391,7 @@ public readonly struct OpenIddictParameter : IEquatable<OpenIddictParameter>
 
                     foreach (var property in element.EnumerateObject())
                     {
-                        hash.Add(property.Name);
+                        hash.Add(property.Name, StringComparer.Ordinal);
                         hash.Add(GetHashCodeFromJsonElement(property.Value));
                     }
 
@@ -441,7 +441,7 @@ public readonly struct OpenIddictParameter : IEquatable<OpenIddictParameter>
                 is JsonElement { ValueKind: JsonValueKind.Object } element
                 => GetParametersFromJsonElement(element),
 
-            _ => ImmutableDictionary.Create<string, OpenIddictParameter>(StringComparer.Ordinal)
+            _ => ImmutableDictionary<string, OpenIddictParameter>.Empty
         };
 
         static IReadOnlyDictionary<string, OpenIddictParameter> GetParametersFromJsonElement(JsonElement element)

src/OpenIddict.Abstractions/Stores/IOpenIddictTokenStore.cs

@@ -323,7 +323,7 @@ public interface IOpenIddictTokenStore<TToken> where TToken : class
     /// <param name="identifier">The application identifier associated with the tokens.</param>
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
     /// <returns>The number of tokens associated with the specified application that were marked as revoked.</returns>
-    ValueTask<long> RevokeByApplicationIdAsync(string identifier, CancellationToken cancellationToken = default);
+    ValueTask<long> RevokeByApplicationIdAsync(string identifier, CancellationToken cancellationToken);
 
     /// <summary>
     /// Revokes all the tokens associated with the specified authorization identifier.
@@ -339,7 +339,7 @@ public interface IOpenIddictTokenStore<TToken> where TToken : class
     /// <param name="subject">The subject associated with the tokens.</param>
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
     /// <returns>The number of tokens associated with the specified subject that were marked as revoked.</returns>
-    ValueTask<long> RevokeBySubjectAsync(string subject, CancellationToken cancellationToken = default);
+    ValueTask<long> RevokeBySubjectAsync(string subject, CancellationToken cancellationToken);
 
     /// <summary>
     /// Sets the application identifier associated with a token.

src/OpenIddict.Client.AspNetCore/OpenIddictClientAspNetCoreConfiguration.cs

@@ -66,7 +66,7 @@ public sealed class OpenIddictClientAspNetCoreConfiguration : IConfigureOptions<
             foreach (var (provider, registrations) in _provider.GetRequiredService<IOptionsMonitor<OpenIddictClientOptions>>()
                 .CurrentValue.Registrations
                 .Where(static registration => !string.IsNullOrEmpty(registration.ProviderName))
-                .GroupBy(static registration => registration.ProviderName)
+                .GroupBy(static registration => registration.ProviderName, StringComparer.Ordinal)
                 .Select(static group => (ProviderName: group.Key, Registrations: group.ToList())))
             {
                 // If an explicit mapping was already added, don't overwrite it.
@@ -148,7 +148,7 @@ public sealed class OpenIddictClientAspNetCoreConfiguration : IConfigureOptions<
         // Ensure the forwarded authentication schemes are mapped to the OpenIddict client forwarder.
         foreach (var group in _provider.GetRequiredService<IOptionsMonitor<OpenIddictClientAspNetCoreOptions>>()
             .CurrentValue.ForwardedAuthenticationSchemes
-            .GroupBy(static scheme => scheme.Name)
+            .GroupBy(static scheme => scheme.Name, StringComparer.Ordinal)
             .Where(group => !ValidateHandlerType<OpenIddictClientAspNetCoreForwarder>(options.SchemeMap, group.Key)))
         {
             builder.AddError(SR.FormatID0414(group.Key));
@@ -195,7 +195,7 @@ public sealed class OpenIddictClientAspNetCoreConfiguration : IConfigureOptions<
             foreach (var (provider, registrations) in _provider.GetRequiredService<IOptionsMonitor<OpenIddictClientOptions>>()
                 .CurrentValue.Registrations
                 .Where(static registration => !string.IsNullOrEmpty(registration.ProviderName))
-                .GroupBy(static registration => registration.ProviderName)
+                .GroupBy(static registration => registration.ProviderName, StringComparer.Ordinal)
                 .Select(static group => (ProviderName: group.Key, Registrations: group.ToList()))
                 .Where(static group => group.Registrations.Count is > 1))
             {

src/OpenIddict.Client.AspNetCore/OpenIddictClientAspNetCoreForwarder.cs

@@ -54,7 +54,7 @@ public sealed class OpenIddictClientAspNetCoreForwarder : IAuthenticationHandler
         await _context.ChallengeAsync(
             scheme: OpenIddictClientAspNetCoreDefaults.AuthenticationScheme,
             properties: new AuthenticationProperties(
-                items: new Dictionary<string, string?>(properties?.Items ?? ImmutableDictionary.Create<string, string?>())
+                items: new Dictionary<string, string?>(properties?.Items ?? ImmutableDictionary<string, string?>.Empty, StringComparer.Ordinal)
                 {
                     [Properties.ProviderName] = _scheme.Name
                 },
@@ -76,7 +76,7 @@ public sealed class OpenIddictClientAspNetCoreForwarder : IAuthenticationHandler
         await _context.ForbidAsync(
             scheme: OpenIddictClientAspNetCoreDefaults.AuthenticationScheme,
             properties: new AuthenticationProperties(
-                items: new Dictionary<string, string?>(properties?.Items ?? ImmutableDictionary.Create<string, string?>())
+                items: new Dictionary<string, string?>(properties?.Items ?? ImmutableDictionary<string, string?>.Empty, StringComparer.Ordinal)
                 {
                     [Properties.ProviderName] = _scheme.Name
                 },
@@ -98,7 +98,7 @@ public sealed class OpenIddictClientAspNetCoreForwarder : IAuthenticationHandler
         await _context.SignOutAsync(
             scheme: OpenIddictClientAspNetCoreDefaults.AuthenticationScheme,
             properties: new AuthenticationProperties(
-                items: new Dictionary<string, string?>(properties?.Items ?? ImmutableDictionary.Create<string, string?>())
+                items: new Dictionary<string, string?>(properties?.Items ?? ImmutableDictionary<string, string?>.Empty, StringComparer.Ordinal)
                 {
                     [Properties.ProviderName] = _scheme.Name
                 },

src/OpenIddict.Client.AspNetCore/OpenIddictClientAspNetCoreHandler.cs

@@ -76,12 +76,12 @@ public sealed class OpenIddictClientAspNetCoreHandler : AuthenticationHandler<Au
             return true;
         }
 
-        else if (context.IsRequestSkipped)
+        if (context.IsRequestSkipped)
         {
             return false;
         }
 
-        else if (context.IsRejected)
+        if (context.IsRejected)
         {
             var notification = new ProcessErrorContext(transaction)
             {
@@ -98,7 +98,7 @@ public sealed class OpenIddictClientAspNetCoreHandler : AuthenticationHandler<Au
                 return true;
             }
 
-            else if (notification.IsRequestSkipped)
+            if (notification.IsRequestSkipped)
             {
                 return false;
             }
@@ -133,7 +133,7 @@ public sealed class OpenIddictClientAspNetCoreHandler : AuthenticationHandler<Au
             return AuthenticateResult.NoResult();
         }
 
-        else if (context.IsRejected)
+        if (context.IsRejected)
         {
             // Note: the missing_token error is special-cased to indicate to ASP.NET Core
             // that no authentication result could be produced due to the lack of token.
@@ -390,7 +390,7 @@ public sealed class OpenIddictClientAspNetCoreHandler : AuthenticationHandler<Au
             return;
         }
 
-        else if (context.IsRejected)
+        if (context.IsRejected)
         {
             var notification = new ProcessErrorContext(transaction)
             {
@@ -436,7 +436,7 @@ public sealed class OpenIddictClientAspNetCoreHandler : AuthenticationHandler<Au
             return;
         }
 
-        else if (context.IsRejected)
+        if (context.IsRejected)
         {
             var notification = new ProcessErrorContext(transaction)
             {

src/OpenIddict.Client.AspNetCore/OpenIddictClientAspNetCoreHandlers.cs

@@ -572,8 +572,7 @@ public static partial class OpenIddictClientAspNetCoreHandlers
                     context.Issuer = uri;
                 }
 
-                if (properties.Items.TryGetValue(Properties.Scope, out string? scope) &&
-                    !string.IsNullOrEmpty(scope))
+                if (properties.Items.TryGetValue(Properties.Scope, out string? scope) && !string.IsNullOrEmpty(scope))
                 {
                     context.Scopes.UnionWith(scope.Split(Separators.Space, StringSplitOptions.RemoveEmptyEntries));
                 }

src/OpenIddict.Client.DataProtection/OpenIddictClientDataProtectionFormatter.cs

@@ -182,7 +182,7 @@ public sealed class OpenIddictClientDataProtectionFormatter : IOpenIddictClientD
         ArgumentNullException.ThrowIfNull(writer);
         ArgumentNullException.ThrowIfNull(principal);
 
-        var properties = new Dictionary<string, string>();
+        var properties = new Dictionary<string, string>(StringComparer.Ordinal);
 
         // Unlike ASP.NET Core Data Protection-based tokens, tokens serialized using the new format
         // can't include authentication properties. To ensure tokens can be used with previous versions

src/OpenIddict.Client.Owin/OpenIddictClientOwinConfiguration.cs

@@ -61,7 +61,7 @@ public sealed class OpenIddictClientOwinConfiguration : IConfigureOptions<OpenId
             foreach (var (provider, registrations) in _provider.GetRequiredService<IOptionsMonitor<OpenIddictClientOptions>>()
                 .CurrentValue.Registrations
                 .Where(static registration => !string.IsNullOrEmpty(registration.ProviderName))
-                .GroupBy(static registration => registration.ProviderName)
+                .GroupBy(static registration => registration.ProviderName, StringComparer.Ordinal)
                 .Select(static group => (ProviderName: group.Key, Registrations: group.ToList())))
             {
                 // If an explicit mapping was already added, don't overwrite it.
@@ -109,7 +109,7 @@ public sealed class OpenIddictClientOwinConfiguration : IConfigureOptions<OpenId
             foreach (var (provider, registrations) in _provider.GetRequiredService<IOptionsMonitor<OpenIddictClientOptions>>()
                 .CurrentValue.Registrations
                 .Where(static registration => !string.IsNullOrEmpty(registration.ProviderName))
-                .GroupBy(static registration => registration.ProviderName)
+                .GroupBy(static registration => registration.ProviderName, StringComparer.Ordinal)
                 .Select(static group => (ProviderName: group.Key, Registrations: group.ToList()))
                 .Where(static group => group.Registrations.Count is > 1))
             {

src/OpenIddict.Client.Owin/OpenIddictClientOwinHandler.cs

@@ -95,12 +95,12 @@ public sealed class OpenIddictClientOwinHandler : AuthenticationHandler<Authenti
             return true;
         }
 
-        else if (context.IsRequestSkipped)
+        if (context.IsRequestSkipped)
         {
             return false;
         }
 
-        else if (context.IsRejected)
+        if (context.IsRejected)
         {
             var notification = new ProcessErrorContext(transaction)
             {
@@ -117,7 +117,7 @@ public sealed class OpenIddictClientOwinHandler : AuthenticationHandler<Authenti
                 return true;
             }
 
-            else if (notification.IsRequestSkipped)
+            if (notification.IsRequestSkipped)
             {
                 return false;
             }
@@ -152,7 +152,7 @@ public sealed class OpenIddictClientOwinHandler : AuthenticationHandler<Authenti
             return null;
         }
 
-        else if (context.IsRejected)
+        if (context.IsRejected)
         {
             // Note: the missing_token error is special-cased to indicate to Katana
             // that no authentication result could be produced due to the lack of token.
@@ -315,7 +315,7 @@ public sealed class OpenIddictClientOwinHandler : AuthenticationHandler<Authenti
                 return;
             }
 
-            else if (context.IsRejected)
+            if (context.IsRejected)
             {
                 var notification = new ProcessErrorContext(transaction)
                 {
@@ -359,7 +359,7 @@ public sealed class OpenIddictClientOwinHandler : AuthenticationHandler<Authenti
                 return;
             }
 
-            else if (context.IsRejected)
+            if (context.IsRejected)
             {
                 var notification = new ProcessErrorContext(transaction)
                 {
@@ -408,7 +408,7 @@ public sealed class OpenIddictClientOwinHandler : AuthenticationHandler<Authenti
                             authenticationTypes: [OpenIddictClientOwinDefaults.AuthenticationType],
                             properties         : new AuthenticationProperties(dictionary: new Dictionary<string, string>(
                                 manager.AuthenticationResponseChallenge.Properties.Dictionary
-                                ?? ImmutableDictionary.Create<string, string>())
+                                ?? ImmutableDictionary<string, string>.Empty, StringComparer.Ordinal)
                                 {
                                     [Properties.ProviderName] = type
                                 }));
@@ -447,7 +447,7 @@ public sealed class OpenIddictClientOwinHandler : AuthenticationHandler<Authenti
                             authenticationTypes: [OpenIddictClientOwinDefaults.AuthenticationType],
                             properties         : new AuthenticationProperties(dictionary: new Dictionary<string, string>(
                                 manager.AuthenticationResponseRevoke.Properties.Dictionary
-                                ?? ImmutableDictionary.Create<string, string>())
+                                ?? ImmutableDictionary<string, string>.Empty, StringComparer.Ordinal)
                                 {
                                     [Properties.ProviderName] = type
                                 }));

src/OpenIddict.Client.Owin/OpenIddictClientOwinHandlers.cs

@@ -578,8 +578,7 @@ public static partial class OpenIddictClientOwinHandlers
                 context.Issuer = uri;
             }
 
-            if (properties.Dictionary.TryGetValue(Properties.Scope, out string? scope) &&
-                !string.IsNullOrEmpty(scope))
+            if (properties.Dictionary.TryGetValue(Properties.Scope, out string? scope) && !string.IsNullOrEmpty(scope))
             {
                 context.Scopes.UnionWith(scope.Split(Separators.Space, StringSplitOptions.RemoveEmptyEntries));
             }

src/OpenIddict.Client.SystemIntegration/OpenIddictClientSystemIntegrationHandlers.Authentication.cs

@@ -228,7 +228,8 @@ public static partial class OpenIddictClientSystemIntegrationHandlers
                         uri: new Uri(context.AuthorizationEndpoint, UriKind.Absolute),
                         parameters: context.Request.GetParameters().ToDictionary(
                             static parameter => parameter.Key,
-                            static parameter => (StringValues) parameter.Value))!;
+                            static parameter => (StringValues) parameter.Value,
+                            StringComparer.Ordinal))!;
 
                     void HandleCallback(NSUrl? url, NSError? error)
                     {
@@ -346,7 +347,8 @@ public static partial class OpenIddictClientSystemIntegrationHandlers
                     uri: new Uri(context.AuthorizationEndpoint, UriKind.Absolute),
                     parameters: context.Request.GetParameters().ToDictionary(
                         static parameter => parameter.Key,
-                        static parameter => (StringValues) parameter.Value)).AbsoluteUri)!);
+                        static parameter => (StringValues) parameter.Value,
+                        StringComparer.Ordinal)).AbsoluteUri)!);
 
                 context.HandleRequest();
 #else
@@ -424,7 +426,8 @@ public static partial class OpenIddictClientSystemIntegrationHandlers
                         uri: new Uri(context.AuthorizationEndpoint, UriKind.Absolute),
                         parameters: context.Request.GetParameters().ToDictionary(
                             static parameter => parameter.Key,
-                            static parameter => (StringValues) parameter.Value)),
+                            static parameter => (StringValues) parameter.Value,
+                            StringComparer.Ordinal)),
                     callbackUri: new Uri(context.RedirectUri, UriKind.Absolute)))
                 {
                     case { ResponseStatus: WebAuthenticationStatus.Success } result
@@ -530,7 +533,8 @@ public static partial class OpenIddictClientSystemIntegrationHandlers
                     uri: new Uri(context.AuthorizationEndpoint, UriKind.Absolute),
                     parameters: context.Request.GetParameters().ToDictionary(
                         static parameter => parameter.Key,
-                        static parameter => (StringValues) parameter.Value));
+                        static parameter => (StringValues) parameter.Value,
+                        StringComparer.Ordinal));
 
                 if (OperatingSystem.IsWindows())
                 {

src/OpenIddict.Client.SystemIntegration/OpenIddictClientSystemIntegrationHandlers.Session.cs

@@ -228,7 +228,8 @@ public static partial class OpenIddictClientSystemIntegrationHandlers
                         uri: new Uri(context.EndSessionEndpoint, UriKind.Absolute),
                         parameters: context.Request.GetParameters().ToDictionary(
                             static parameter => parameter.Key,
-                            static parameter => (StringValues) parameter.Value))!;
+                            static parameter => (StringValues) parameter.Value,
+                            StringComparer.Ordinal))!;
 
                     void HandleCallback(NSUrl? url, NSError? error)
                     {
@@ -346,7 +347,8 @@ public static partial class OpenIddictClientSystemIntegrationHandlers
                     uri: new Uri(context.EndSessionEndpoint, UriKind.Absolute),
                     parameters: context.Request.GetParameters().ToDictionary(
                         static parameter => parameter.Key,
-                        static parameter => (StringValues) parameter.Value)).AbsoluteUri)!);
+                        static parameter => (StringValues) parameter.Value,
+                        StringComparer.Ordinal)).AbsoluteUri)!);
 
                 context.HandleRequest();
 #else
@@ -424,7 +426,8 @@ public static partial class OpenIddictClientSystemIntegrationHandlers
                         uri: new Uri(context.EndSessionEndpoint, UriKind.Absolute),
                         parameters: context.Request.GetParameters().ToDictionary(
                             static parameter => parameter.Key,
-                            static parameter => (StringValues) parameter.Value)),
+                            static parameter => (StringValues) parameter.Value,
+                            StringComparer.Ordinal)),
                     callbackUri: new Uri(context.PostLogoutRedirectUri, UriKind.Absolute)))
                 {
                     case { ResponseStatus: WebAuthenticationStatus.Success } result
@@ -530,7 +533,8 @@ public static partial class OpenIddictClientSystemIntegrationHandlers
                     uri: new Uri(context.EndSessionEndpoint, UriKind.Absolute),
                     parameters: context.Request.GetParameters().ToDictionary(
                         static parameter => parameter.Key,
-                        static parameter => (StringValues) parameter.Value));
+                        static parameter => (StringValues) parameter.Value,
+                        StringComparer.Ordinal));
 
                 if (OperatingSystem.IsWindows())
                 {

src/OpenIddict.Client.SystemIntegration/OpenIddictClientSystemIntegrationHandlers.cs

@@ -655,13 +655,13 @@ public static partial class OpenIddictClientSystemIntegrationHandlers
                     return;
                 }
 
-                else if (notification.IsRequestSkipped)
+                if (notification.IsRequestSkipped)
                 {
                     context.SkipRequest();
                     return;
                 }
 
-                else if (notification.IsRejected)
+                if (notification.IsRejected)
                 {
                     context.Reject(
                         error: notification.Error ?? Errors.InvalidRequest,

src/OpenIddict.Client.SystemIntegration/OpenIddictClientSystemIntegrationMarshal.cs

@@ -19,7 +19,7 @@ public sealed class OpenIddictClientSystemIntegrationMarshal
     private readonly ConcurrentDictionary<string, Lazy<(
         string RequestForgeryProtection,
         SemaphoreSlim Semaphore,
-        TaskCompletionSource<ProcessAuthenticationContext> TaskCompletionSource)>> _tracker = new();
+        TaskCompletionSource<ProcessAuthenticationContext> TaskCompletionSource)>> _tracker = new(StringComparer.Ordinal);
 
     /// <summary>
     /// Determines whether the authentication demand corresponding to the specified nonce is tracked.

src/OpenIddict.Client.SystemNetHttp/OpenIddictClientSystemNetHttpHandlers.cs

@@ -374,7 +374,7 @@ public static partial class OpenIddictClientSystemNetHttpHandlers
             return ValueTask.CompletedTask;
 
             static string? EscapeDataString(string? value)
-                => value is not null ? Uri.EscapeDataString(value).Replace("%20", "+") : null;
+                => value is not null ? Uri.EscapeDataString(value).Replace("%20", "+", StringComparison.Ordinal) : null;
         }
     }
 
@@ -417,7 +417,8 @@ public static partial class OpenIddictClientSystemNetHttpHandlers
                 request.RequestUri = OpenIddictHelpers.AddQueryStringParameters(request.RequestUri,
                     context.Transaction.Request.GetParameters().ToDictionary(
                         static parameter => parameter.Key,
-                        static parameter => (StringValues) parameter.Value));
+                        static parameter => (StringValues) parameter.Value,
+                        StringComparer.Ordinal));
             }
 
             // For POST requests, attach the request parameters to the request form by default.
@@ -609,7 +610,7 @@ public static partial class OpenIddictClientSystemNetHttpHandlers
                     continue;
                 }
 
-                else if (string.Equals(encoding, ContentEncodings.Gzip, StringComparison.OrdinalIgnoreCase))
+                if (string.Equals(encoding, ContentEncodings.Gzip, StringComparison.OrdinalIgnoreCase))
                 {
                     stream ??= await response.Content.ReadAsStreamAsync().WaitAsync(context.CancellationToken);
                     stream = new GZipStream(stream, CompressionMode.Decompress);

src/OpenIddict.Client.WebIntegration/OpenIddictClientWebIntegrationExtensions.cs

@@ -14,7 +14,7 @@ namespace Microsoft.Extensions.DependencyInjection;
 /// <summary>
 /// Exposes extensions allowing to register the OpenIddict client Web integration services.
 /// </summary>
-public static partial class OpenIddictClientWebIntegrationExtensions
+public static class OpenIddictClientWebIntegrationExtensions
 {
     /// <summary>
     /// Registers the OpenIddict client Web integration services in the DI container.

src/OpenIddict.Client.WebIntegration/OpenIddictClientWebIntegrationHandlers.Exchange.cs

@@ -270,7 +270,7 @@ public static partial class OpenIddictClientWebIntegrationHandlers
                 {
                     request.RequestUri = OpenIddictHelpers.AddQueryStringParameters(
                         uri: request.RequestUri,
-                        parameters: new Dictionary<string, StringValues>
+                        parameters: new Dictionary<string, StringValues>(StringComparer.Ordinal)
                         {
                             ["chat_os_type"] = "bot",
                             ["chat_version"] = "1.30.0"

src/OpenIddict.Client.WebIntegration/OpenIddictClientWebIntegrationHandlers.Introspection.cs

@@ -66,7 +66,7 @@ public static partial class OpenIddictClientWebIntegrationHandlers
                         }
                     }
 
-                    context.Response.Scope = string.Join(" ", scopes);
+                    context.Response.Scope = string.Join(Separators.Space[0], scopes);
                 }
 
                 return ValueTask.CompletedTask;

src/OpenIddict.Client.WebIntegration/OpenIddictClientWebIntegrationHandlers.cs

@@ -161,13 +161,11 @@ public static partial class OpenIddictClientWebIntegrationHandlers
                 //
                 // See https://shopify.dev/docs/apps/auth/oauth/getting-started#remove-the-hmac-parameter-from-the-query-string
                 // for more information.
-                foreach (var (name, value) in
-                    from parameter in OpenIddictHelpers.ParseQuery(context.RequestUri!.Query)
-                    where !string.IsNullOrEmpty(parameter.Key)
-                    where !string.Equals(parameter.Key, "hmac", StringComparison.Ordinal)
-                    orderby parameter.Key ascending
-                    from value in parameter.Value
-                    select (Name: parameter.Key, Value: value))
+                foreach (var (name, value) in OpenIddictHelpers.ParseQuery(context.RequestUri!.Query)
+                    .Where(static parameter => !string.IsNullOrEmpty(parameter.Key))
+                    .Where(static parameter => !string.Equals(parameter.Key, "hmac", StringComparison.Ordinal))
+                    .OrderBy(static parameter => parameter.Key, StringComparer.Ordinal)
+                    .SelectMany(static parameter => parameter.Value, static (parameter, value) => (Name: parameter.Key, Value: value)))
                 {
                     if (builder.Length is > 0)
                     {
@@ -1187,7 +1185,7 @@ public static partial class OpenIddictClientWebIntegrationHandlers
             {
                 var settings = context.Registration.GetDailymotionSettings();
 
-                context.UserInfoRequest["fields"] = string.Join(",", settings.UserFields);
+                context.UserInfoRequest["fields"] = string.Join(Separators.Comma[0], settings.UserFields);
             }
 
             // Disqus requires sending the client identifier (called "public
@@ -1204,7 +1202,7 @@ public static partial class OpenIddictClientWebIntegrationHandlers
             {
                 var settings = context.Registration.GetFacebookSettings();
 
-                context.UserInfoRequest["fields"] = string.Join(",", settings.Fields);
+                context.UserInfoRequest["fields"] = string.Join(Separators.Comma[0], settings.Fields);
             }
 
             // Linear's userinfo endpoint is a GraphQL implementation that requires
@@ -1213,7 +1211,7 @@ public static partial class OpenIddictClientWebIntegrationHandlers
             {
                 var settings = context.Registration.GetLinearSettings();
 
-                context.UserInfoRequest["query"] = $"query {{ viewer {{ {string.Join(" ", settings.UserFields)} }} }}";
+                context.UserInfoRequest["query"] = $"query {{ viewer {{ {string.Join(Separators.Space[0], settings.UserFields)} }} }}";
             }
 
             // Meetup's userinfo endpoint is a GraphQL implementation that requires
@@ -1222,7 +1220,7 @@ public static partial class OpenIddictClientWebIntegrationHandlers
             {
                 var settings = context.Registration.GetMeetupSettings();
 
-                context.UserInfoRequest["query"] = $"query {{ self {{ {string.Join(" ", settings.UserFields)} }} }}";
+                context.UserInfoRequest["query"] = $"query {{ self {{ {string.Join(Separators.Space[0], settings.UserFields)} }} }}";
             }
 
             // Patreon limits the number of fields returned by the userinfo endpoint
@@ -1232,7 +1230,7 @@ public static partial class OpenIddictClientWebIntegrationHandlers
             {
                 var settings = context.Registration.GetPatreonSettings();
 
-                context.UserInfoRequest["fields[user]"] = string.Join(",", settings.UserFields);
+                context.UserInfoRequest["fields[user]"] = string.Join(Separators.Comma[0], settings.UserFields);
             }
 
             // StackOverflow requires sending an application key and a site parameter
@@ -1274,9 +1272,9 @@ public static partial class OpenIddictClientWebIntegrationHandlers
             {
                 var settings = context.Registration.GetTwitterSettings();
 
-                context.UserInfoRequest["expansions"] = string.Join(",", settings.Expansions);
-                context.UserInfoRequest["tweet.fields"] = string.Join(",", settings.TweetFields);
-                context.UserInfoRequest["user.fields"] = string.Join(",", settings.UserFields);
+                context.UserInfoRequest["expansions"] = string.Join(Separators.Comma[0], settings.Expansions);
+                context.UserInfoRequest["tweet.fields"] = string.Join(Separators.Comma[0], settings.TweetFields);
+                context.UserInfoRequest["user.fields"] = string.Join(Separators.Comma[0], settings.UserFields);
             }
 
             // Weibo requires sending the user identifier as part of the userinfo request.
@@ -1880,11 +1878,11 @@ public static partial class OpenIddictClientWebIntegrationHandlers
                 // the standard format (that requires using a space as the scope separator):
                 ProviderTypes.Deezer or ProviderTypes.Disqus  or ProviderTypes.Shopify or
                 ProviderTypes.Strava or ProviderTypes.Todoist or ProviderTypes.Weibo
-                    => string.Join(",", context.Scopes),
+                    => string.Join(Separators.Comma[0], context.Scopes),
 
                 // The following providers are known to use plus-separated scopes instead of
                 // the standard format (that requires using a space as the scope separator):
-                ProviderTypes.Trovo => string.Join("+", context.Scopes),
+                ProviderTypes.Trovo => string.Join(Separators.Plus[0], context.Scopes),
 
                 _ => context.Request.Scope
             };

src/OpenIddict.Client.WebIntegration/OpenIddictClientWebIntegrationOptions.cs

@@ -9,6 +9,6 @@ namespace OpenIddict.Client.WebIntegration;
 /// <summary>
 /// Provides various settings needed to configure the OpenIddict client Web integration.
 /// </summary>
-public sealed partial class OpenIddictClientWebIntegrationOptions
+public sealed class OpenIddictClientWebIntegrationOptions
 {
 }

src/OpenIddict.Client/OpenIddictClientHandlers.Authentication.cs

@@ -89,7 +89,7 @@ public static partial class OpenIddictClientHandlers
                     return;
                 }
 
-                else if (notification.IsRequestSkipped)
+                if (notification.IsRequestSkipped)
                 {
                     context.SkipRequest();
                     return;
@@ -138,13 +138,13 @@ public static partial class OpenIddictClientHandlers
                     return;
                 }
 
-                else if (notification.IsRequestSkipped)
+                if (notification.IsRequestSkipped)
                 {
                     context.SkipRequest();
                     return;
                 }
 
-                else if (notification.IsRejected)
+                if (notification.IsRejected)
                 {
                     context.Reject(
                         error: notification.Error ?? Errors.InvalidRequest,
@@ -419,13 +419,13 @@ public static partial class OpenIddictClientHandlers
                     return;
                 }
 
-                else if (notification.IsRequestSkipped)
+                if (notification.IsRequestSkipped)
                 {
                     context.SkipRequest();
                     return;
                 }
 
-                else if (notification.IsRejected)
+                if (notification.IsRejected)
                 {
                     context.Reject(
                         error: notification.Error ?? Errors.InvalidRequest,
@@ -478,13 +478,13 @@ public static partial class OpenIddictClientHandlers
                     return;
                 }
 
-                else if (notification.IsRequestSkipped)
+                if (notification.IsRequestSkipped)
                 {
                     context.SkipRequest();
                     return;
                 }
 
-                else if (notification.IsRejected)
+                if (notification.IsRejected)
                 {
                     context.Reject(
                         error: notification.Error ?? Errors.InvalidRequest,
@@ -531,13 +531,13 @@ public static partial class OpenIddictClientHandlers
                     return;
                 }
 
-                else if (notification.IsRequestSkipped)
+                if (notification.IsRequestSkipped)
                 {
                     context.SkipRequest();
                     return;
                 }
 
-                else if (notification.IsRejected)
+                if (notification.IsRejected)
                 {
                     context.Reject(
                         error: notification.Error ?? Errors.InvalidRequest,
@@ -585,7 +585,7 @@ public static partial class OpenIddictClientHandlers
                     return;
                 }
 
-                else if (notification.IsRequestSkipped)
+                if (notification.IsRequestSkipped)
                 {
                     context.SkipRequest();
                     return;
@@ -676,13 +676,13 @@ public static partial class OpenIddictClientHandlers
                     return;
                 }
 
-                else if (notification.IsRequestSkipped)
+                if (notification.IsRequestSkipped)
                 {
                     context.SkipRequest();
                     return;
                 }
 
-                else if (notification.IsRejected)
+                if (notification.IsRejected)
                 {
                     context.Reject(
                         error: notification.Error ?? Errors.InvalidRequest,

src/OpenIddict.Client/OpenIddictClientHandlers.Protection.cs

@@ -410,7 +410,7 @@ public static partial class OpenIddictClientHandlers
                     foreach (var claim in result.ClaimsIdentity.Claims)
                     {
                         // Exclude claims starting with "oi_" from tokens that are not fully trusted.
-                        if (claim.Type.StartsWith(Claims.Prefixes.Private))
+                        if (claim.Type.StartsWith(Claims.Prefixes.Private, StringComparison.Ordinal))
                         {
                             continue;
                         }
@@ -424,7 +424,7 @@ public static partial class OpenIddictClientHandlers
                     identity = result.ClaimsIdentity.Clone(claim => claim switch
                     {
                         // Exclude claims starting with "oi_", unless the token is a state token.
-                        { Type: string type } when type.StartsWith(Claims.Prefixes.Private) &&
+                        { Type: string type } when type.StartsWith(Claims.Prefixes.Private, StringComparison.Ordinal) &&
                             result.TokenType is not JsonWebTokenTypes.Private.StateToken => false,
 
                         _ => true // Allow any other claim.

src/OpenIddict.Client/OpenIddictClientHandlers.Session.cs

@@ -74,7 +74,7 @@ public static partial class OpenIddictClientHandlers
                     return;
                 }
 
-                else if (notification.IsRequestSkipped)
+                if (notification.IsRequestSkipped)
                 {
                     context.SkipRequest();
                     return;
@@ -121,13 +121,13 @@ public static partial class OpenIddictClientHandlers
                     return;
                 }
 
-                else if (notification.IsRequestSkipped)
+                if (notification.IsRequestSkipped)
                 {
                     context.SkipRequest();
                     return;
                 }
 
-                else if (notification.IsRejected)
+                if (notification.IsRejected)
                 {
                     context.Reject(
                         error: notification.Error ?? Errors.InvalidRequest,
@@ -210,13 +210,13 @@ public static partial class OpenIddictClientHandlers
                     return;
                 }
 
-                else if (notification.IsRequestSkipped)
+                if (notification.IsRequestSkipped)
                 {
                     context.SkipRequest();
                     return;
                 }
 
-                else if (notification.IsRejected)
+                if (notification.IsRejected)
                 {
                     context.Reject(
                         error: notification.Error ?? Errors.InvalidRequest,
@@ -269,13 +269,13 @@ public static partial class OpenIddictClientHandlers
                     return;
                 }
 
-                else if (notification.IsRequestSkipped)
+                if (notification.IsRequestSkipped)
                 {
                     context.SkipRequest();
                     return;
                 }
 
-                else if (notification.IsRejected)
+                if (notification.IsRejected)
                 {
                     context.Reject(
                         error: notification.Error ?? Errors.InvalidRequest,
@@ -322,13 +322,13 @@ public static partial class OpenIddictClientHandlers
                     return;
                 }
 
-                else if (notification.IsRequestSkipped)
+                if (notification.IsRequestSkipped)
                 {
                     context.SkipRequest();
                     return;
                 }
 
-                else if (notification.IsRejected)
+                if (notification.IsRejected)
                 {
                     context.Reject(
                         error: notification.Error ?? Errors.InvalidRequest,
@@ -376,7 +376,7 @@ public static partial class OpenIddictClientHandlers
                     return;
                 }
 
-                else if (notification.IsRequestSkipped)
+                if (notification.IsRequestSkipped)
                 {
                     context.SkipRequest();
                     return;
@@ -425,13 +425,13 @@ public static partial class OpenIddictClientHandlers
                     return;
                 }
 
-                else if (notification.IsRequestSkipped)
+                if (notification.IsRequestSkipped)
                 {
                     context.SkipRequest();
                     return;
                 }
 
-                else if (notification.IsRejected)
+                if (notification.IsRejected)
                 {
                     context.Reject(
                         error: notification.Error ?? Errors.InvalidRequest,

src/OpenIddict.Client/OpenIddictClientHandlers.cs

@@ -713,13 +713,13 @@ public static partial class OpenIddictClientHandlers
                 return;
             }
 
-            else if (notification.IsRequestSkipped)
+            if (notification.IsRequestSkipped)
             {
                 context.SkipRequest();
                 return;
             }
 
-            else if (notification.IsRejected)
+            if (notification.IsRejected)
             {
                 if (context.RejectStateToken)
                 {
@@ -1626,13 +1626,13 @@ public static partial class OpenIddictClientHandlers
                 return;
             }
 
-            else if (notification.IsRequestSkipped)
+            if (notification.IsRequestSkipped)
             {
                 context.SkipRequest();
                 return;
             }
 
-            else if (notification.IsRejected)
+            if (notification.IsRejected)
             {
                 if (context.RejectFrontchannelIdentityToken)
                 {
@@ -1674,8 +1674,8 @@ public static partial class OpenIddictClientHandlers
             Debug.Assert(context.FrontchannelIdentityTokenPrincipal is { Identity: ClaimsIdentity }, SR.GetResourceString(SR.ID4006));
 
             foreach (var group in context.FrontchannelIdentityTokenPrincipal.Claims
-                .GroupBy(static claim => claim.Type)
-                .ToDictionary(static group => group.Key, group => group.ToList())
+                .GroupBy(static claim => claim.Type, StringComparer.Ordinal)
+                .ToDictionary(static group => group.Key, group => group.ToList(), StringComparer.Ordinal)
                 .Where(static group => !ValidateClaimGroup(group.Key, group.Value)))
             {
                 context.Reject(
@@ -1806,7 +1806,8 @@ public static partial class OpenIddictClientHandlers
             // In any case, the client identifier of the application MUST be included in the audiences.
             // See https://openid.net/specs/openid-connect-core-1_0.html#IDTokenValidation for more information.
             var audiences = context.FrontchannelIdentityTokenPrincipal.GetClaims(Claims.Audience);
-            if (!string.IsNullOrEmpty(context.Registration.ClientId) && !audiences.Contains(context.Registration.ClientId))
+            if (!string.IsNullOrEmpty(context.Registration.ClientId) &&
+                !audiences.Contains(context.Registration.ClientId, StringComparer.Ordinal))
             {
                 context.Reject(
                     error: Errors.InvalidRequest,
@@ -2150,13 +2151,13 @@ public static partial class OpenIddictClientHandlers
                 return;
             }
 
-            else if (notification.IsRequestSkipped)
+            if (notification.IsRequestSkipped)
             {
                 context.SkipRequest();
                 return;
             }
 
-            else if (notification.IsRejected)
+            if (notification.IsRejected)
             {
                 if (context.RejectFrontchannelAccessToken)
                 {
@@ -2221,13 +2222,13 @@ public static partial class OpenIddictClientHandlers
                 return;
             }
 
-            else if (notification.IsRequestSkipped)
+            if (notification.IsRequestSkipped)
             {
                 context.SkipRequest();
                 return;
             }
 
-            else if (notification.IsRejected)
+            if (notification.IsRejected)
             {
                 if (context.RejectAuthorizationCode)
                 {
@@ -2697,7 +2698,7 @@ public static partial class OpenIddictClientHandlers
                     // Note: the final OAuth 2.0 specification requires using a space as the scope separator.
                     // Clients that need to deal with older or non-compliant implementations can register
                     // a custom handler to use a different separator (typically, a comma).
-                    context.TokenRequest.Scope = string.Join(" ", context.Scopes);
+                    context.TokenRequest.Scope = string.Join(Separators.Space[0], context.Scopes);
                 }
             }
 
@@ -2908,13 +2909,13 @@ public static partial class OpenIddictClientHandlers
                 return;
             }
 
-            else if (notification.IsRequestSkipped)
+            if (notification.IsRequestSkipped)
             {
                 context.SkipRequest();
                 return;
             }
 
-            else if (notification.IsRejected)
+            if (notification.IsRejected)
             {
                 context.Reject(
                     error: notification.Error ?? Errors.InvalidRequest,
@@ -3363,13 +3364,13 @@ public static partial class OpenIddictClientHandlers
                 return;
             }
 
-            else if (notification.IsRequestSkipped)
+            if (notification.IsRequestSkipped)
             {
                 context.SkipRequest();
                 return;
             }
 
-            else if (notification.IsRejected)
+            if (notification.IsRejected)
             {
                 if (context.RejectBackchannelIdentityToken)
                 {
@@ -3411,8 +3412,8 @@ public static partial class OpenIddictClientHandlers
             Debug.Assert(context.BackchannelIdentityTokenPrincipal is { Identity: ClaimsIdentity }, SR.GetResourceString(SR.ID4006));
 
             foreach (var group in context.BackchannelIdentityTokenPrincipal.Claims
-                .GroupBy(static claim => claim.Type)
-                .ToDictionary(static group => group.Key, group => group.ToList())
+                .GroupBy(static claim => claim.Type, StringComparer.Ordinal)
+                .ToDictionary(static group => group.Key, group => group.ToList(), StringComparer.Ordinal)
                 .Where(static group => !ValidateClaimGroup(group.Key, group.Value)))
             {
                 context.Reject(
@@ -3543,7 +3544,8 @@ public static partial class OpenIddictClientHandlers
             // In any case, the client identifier of the application MUST be included in the audiences.
             // See https://openid.net/specs/openid-connect-core-1_0.html#IDTokenValidation for more information.
             var audiences = context.BackchannelIdentityTokenPrincipal.GetClaims(Claims.Audience);
-            if (!string.IsNullOrEmpty(context.Registration.ClientId) && !audiences.Contains(context.Registration.ClientId))
+            if (!string.IsNullOrEmpty(context.Registration.ClientId) &&
+                !audiences.Contains(context.Registration.ClientId, StringComparer.Ordinal))
             {
                 context.Reject(
                     error: Errors.InvalidRequest,
@@ -3851,13 +3853,13 @@ public static partial class OpenIddictClientHandlers
                 return;
             }
 
-            else if (notification.IsRequestSkipped)
+            if (notification.IsRequestSkipped)
             {
                 context.SkipRequest();
                 return;
             }
 
-            else if (notification.IsRejected)
+            if (notification.IsRejected)
             {
                 if (context.RejectBackchannelAccessToken)
                 {
@@ -3920,13 +3922,13 @@ public static partial class OpenIddictClientHandlers
                 return;
             }
 
-            else if (notification.IsRequestSkipped)
+            if (notification.IsRequestSkipped)
             {
                 context.SkipRequest();
                 return;
             }
 
-            else if (notification.IsRejected)
+            if (notification.IsRejected)
             {
                 if (context.RejectIssuedToken)
                 {
@@ -3991,13 +3993,13 @@ public static partial class OpenIddictClientHandlers
                 return;
             }
 
-            else if (notification.IsRequestSkipped)
+            if (notification.IsRequestSkipped)
             {
                 context.SkipRequest();
                 return;
             }
 
-            else if (notification.IsRejected)
+            if (notification.IsRejected)
             {
                 if (context.RejectRefreshToken)
                 {
@@ -4493,13 +4495,13 @@ public static partial class OpenIddictClientHandlers
                 return;
             }
 
-            else if (notification.IsRequestSkipped)
+            if (notification.IsRequestSkipped)
             {
                 context.SkipRequest();
                 return;
             }
 
-            else if (notification.IsRejected)
+            if (notification.IsRejected)
             {
                 if (context.RejectUserInfoToken)
                 {
@@ -4542,8 +4544,8 @@ public static partial class OpenIddictClientHandlers
             Debug.Assert(context.UserInfoTokenPrincipal is { Identity: ClaimsIdentity }, SR.GetResourceString(SR.ID4006));
 
             foreach (var group in context.UserInfoTokenPrincipal.Claims
-                .GroupBy(static claim => claim.Type)
-                .ToDictionary(static group => group.Key, group => group.ToList())
+                .GroupBy(static claim => claim.Type, StringComparer.Ordinal)
+                .ToDictionary(static group => group.Key, group => group.ToList(), StringComparer.Ordinal)
                 .Where(static group => !ValidateClaimGroup(group.Key, group.Value)))
             {
                 context.Reject(
@@ -4907,8 +4909,8 @@ public static partial class OpenIddictClientHandlers
             }
 
             foreach (var group in context.Principal.Claims
-                .GroupBy(static claim => claim.Type)
-                .ToDictionary(static group => group.Key, static group => group.ToList())
+                .GroupBy(static claim => claim.Type, StringComparer.Ordinal)
+                .ToDictionary(static group => group.Key, static group => group.ToList(), StringComparer.Ordinal)
                 .Where(static group => !ValidateClaimGroup(group.Key, group.Value)))
             {
                 throw new InvalidOperationException(SR.FormatID0424(group.Key));
@@ -5848,13 +5850,13 @@ public static partial class OpenIddictClientHandlers
                 return;
             }
 
-            else if (notification.IsRequestSkipped)
+            if (notification.IsRequestSkipped)
             {
                 context.SkipRequest();
                 return;
             }
 
-            else if (notification.IsRejected)
+            if (notification.IsRejected)
             {
                 context.Reject(
                     error: notification.Error ?? Errors.InvalidRequest,
@@ -5912,7 +5914,7 @@ public static partial class OpenIddictClientHandlers
                 // Note: the final OAuth 2.0 specification requires using a space as the scope separator.
                 // Clients that need to deal with older or non-compliant implementations can register
                 // a custom handler to use a different separator (typically, a comma).
-                context.Request.Scope = string.Join(" ", context.Scopes);
+                context.Request.Scope = string.Join(Separators.Space[0], context.Scopes);
             }
 
             // If a nonce was generated and the request is an OpenID Connect request where an authorization
@@ -6275,7 +6277,7 @@ public static partial class OpenIddictClientHandlers
                 // Note: the final OAuth 2.0 specification requires using a space as the scope separator.
                 // Clients that need to deal with older or non-compliant implementations can register
                 // a custom handler to use a different separator (typically, a comma).
-                context.DeviceAuthorizationRequest.Scope = string.Join(" ", context.Scopes);
+                context.DeviceAuthorizationRequest.Scope = string.Join(Separators.Space[0], context.Scopes);
             }
 
             return ValueTask.CompletedTask;
@@ -6737,13 +6739,13 @@ public static partial class OpenIddictClientHandlers
                 return;
             }
 
-            else if (notification.IsRequestSkipped)
+            if (notification.IsRequestSkipped)
             {
                 context.SkipRequest();
                 return;
             }
 
-            else if (notification.IsRejected)
+            if (notification.IsRejected)
             {
                 context.Reject(
                     error: notification.Error ?? Errors.InvalidRequest,
@@ -7900,13 +7902,13 @@ public static partial class OpenIddictClientHandlers
                 return;
             }
 
-            else if (notification.IsRequestSkipped)
+            if (notification.IsRequestSkipped)
             {
                 context.SkipRequest();
                 return;
             }
 
-            else if (notification.IsRejected)
+            if (notification.IsRejected)
             {
                 context.Reject(
                     error: notification.Error ?? Errors.InvalidRequest,
@@ -8705,13 +8707,13 @@ public static partial class OpenIddictClientHandlers
                 return;
             }
 
-            else if (notification.IsRequestSkipped)
+            if (notification.IsRequestSkipped)
             {
                 context.SkipRequest();
                 return;
             }
 
-            else if (notification.IsRejected)
+            if (notification.IsRejected)
             {
                 context.Reject(
                     error: notification.Error ?? Errors.InvalidRequest,
@@ -8908,8 +8910,8 @@ public static partial class OpenIddictClientHandlers
             }
 
             foreach (var group in context.Principal.Claims
-                .GroupBy(static claim => claim.Type)
-                .ToDictionary(static group => group.Key, static group => group.ToList())
+                .GroupBy(static claim => claim.Type, StringComparer.Ordinal)
+                .ToDictionary(static group => group.Key, static group => group.ToList(), StringComparer.Ordinal)
                 .Where(static group => !ValidateClaimGroup(group.Key, group.Value)))
             {
                 throw new InvalidOperationException(SR.FormatID0424(group.Key));
@@ -9358,13 +9360,13 @@ public static partial class OpenIddictClientHandlers
                 return;
             }
 
-            else if (notification.IsRequestSkipped)
+            if (notification.IsRequestSkipped)
             {
                 context.SkipRequest();
                 return;
             }
 
-            else if (notification.IsRejected)
+            if (notification.IsRejected)
             {
                 context.Reject(
                     error: notification.Error ?? Errors.InvalidRequest,

src/OpenIddict.Client/OpenIddictClientService.cs

@@ -294,30 +294,27 @@ public class OpenIddictClientService
                 context.Error, context.ErrorDescription, context.ErrorUri);
         }
 
-        else
-        {
-            Debug.Assert(context.Registration.Issuer is { IsAbsoluteUri: true }, SR.GetResourceString(SR.ID4013));
-
-            return new()
-            {
-                AuthorizationCode = context.AuthorizationCode,
-                AuthorizationResponse = context.Request is not null ? new(context.Request.GetParameters()) : new(),
-                BackchannelAccessToken = context.BackchannelAccessToken,
-                BackchannelAccessTokenExpirationDate = context.BackchannelAccessTokenExpirationDate,
-                BackchannelIdentityToken = context.BackchannelIdentityToken,
-                BackchannelIdentityTokenPrincipal = context.BackchannelIdentityTokenPrincipal,
-                FrontchannelAccessToken = context.FrontchannelAccessToken,
-                FrontchannelAccessTokenExpirationDate = context.FrontchannelAccessTokenExpirationDate,
-                FrontchannelIdentityToken = context.FrontchannelIdentityToken,
-                FrontchannelIdentityTokenPrincipal = context.FrontchannelIdentityTokenPrincipal,
-                Principal = context.MergedPrincipal,
-                Properties = context.Properties,
-                RefreshToken = context.RefreshToken,
-                StateTokenPrincipal = context.StateTokenPrincipal,
-                TokenResponse = context.TokenResponse ?? new(),
-                UserInfoTokenPrincipal = context.UserInfoTokenPrincipal
-            };
-        }
+        Debug.Assert(context.Registration.Issuer is { IsAbsoluteUri: true }, SR.GetResourceString(SR.ID4013));
+
+        return new()
+        {
+            AuthorizationCode = context.AuthorizationCode,
+            AuthorizationResponse = context.Request is not null ? new(context.Request.GetParameters()) : new(),
+            BackchannelAccessToken = context.BackchannelAccessToken,
+            BackchannelAccessTokenExpirationDate = context.BackchannelAccessTokenExpirationDate,
+            BackchannelIdentityToken = context.BackchannelIdentityToken,
+            BackchannelIdentityTokenPrincipal = context.BackchannelIdentityTokenPrincipal,
+            FrontchannelAccessToken = context.FrontchannelAccessToken,
+            FrontchannelAccessTokenExpirationDate = context.FrontchannelAccessTokenExpirationDate,
+            FrontchannelIdentityToken = context.FrontchannelIdentityToken,
+            FrontchannelIdentityTokenPrincipal = context.FrontchannelIdentityTokenPrincipal,
+            Principal = context.MergedPrincipal,
+            Properties = context.Properties,
+            RefreshToken = context.RefreshToken,
+            StateTokenPrincipal = context.StateTokenPrincipal,
+            TokenResponse = context.TokenResponse ?? new(),
+            UserInfoTokenPrincipal = context.UserInfoTokenPrincipal
+        };
     }
 
     /// <summary>
@@ -652,24 +649,21 @@ public class OpenIddictClientService
                         context.Error, context.ErrorDescription, context.ErrorUri);
                 }
 
-                else
-                {
-                    Debug.Assert(context.Registration.Issuer is { IsAbsoluteUri: true }, SR.GetResourceString(SR.ID4013));
+                Debug.Assert(context.Registration.Issuer is { IsAbsoluteUri: true }, SR.GetResourceString(SR.ID4013));
 
-                    return new()
-                    {
-                        AccessToken = context.BackchannelAccessToken!,
-                        AccessTokenExpirationDate = context.BackchannelAccessTokenExpirationDate,
-                        IdentityToken = context.BackchannelIdentityToken,
-                        IdentityTokenPrincipal = context.BackchannelIdentityTokenPrincipal,
-                        Principal = context.MergedPrincipal,
-                        Properties = context.Properties,
-                        RefreshToken = context.RefreshToken,
-                        TokenResponse = context.TokenResponse ?? new(),
-                        UserInfoToken = context.UserInfoToken,
-                        UserInfoTokenPrincipal = context.UserInfoTokenPrincipal
-                    };
-                }
+                return new()
+                {
+                    AccessToken = context.BackchannelAccessToken!,
+                    AccessTokenExpirationDate = context.BackchannelAccessTokenExpirationDate,
+                    IdentityToken = context.BackchannelIdentityToken,
+                    IdentityTokenPrincipal = context.BackchannelIdentityTokenPrincipal,
+                    Principal = context.MergedPrincipal,
+                    Properties = context.Properties,
+                    RefreshToken = context.RefreshToken,
+                    TokenResponse = context.TokenResponse ?? new(),
+                    UserInfoToken = context.UserInfoToken,
+                    UserInfoTokenPrincipal = context.UserInfoTokenPrincipal
+                };
             }
 
             catch (ProtocolException exception) when (exception.Error is Errors.AuthorizationPending)

src/OpenIddict.Core/Managers/OpenIddictApplicationManager.cs

@@ -582,13 +582,7 @@ public class OpenIddictApplicationManager<TApplication> : IOpenIddictApplication
     {
         ArgumentNullException.ThrowIfNull(application);
 
-        var names = await Store.GetDisplayNamesAsync(application, cancellationToken);
-        if (names is not { Count: > 0 })
-        {
-            return ImmutableDictionary.Create<CultureInfo, string>();
-        }
-
-        return names;
+        return await Store.GetDisplayNamesAsync(application, cancellationToken) is { IsEmpty: false } names ? names : [];
     }
 
     /// <summary>
@@ -2007,7 +2001,9 @@ public class OpenIddictApplicationManager<TApplication> : IOpenIddictApplication
 
     /// <inheritdoc/>
     ValueTask<string?> IOpenIddictApplicationManager.GetLocalizedDisplayNameAsync(object application, CancellationToken cancellationToken)
+#pragma warning disable MA0011
         => GetLocalizedDisplayNameAsync((TApplication) application, cancellationToken);
+#pragma warning restore MA0011
 
     /// <inheritdoc/>
     ValueTask<string?> IOpenIddictApplicationManager.GetLocalizedDisplayNameAsync(object application, CultureInfo culture, CancellationToken cancellationToken)

src/OpenIddict.Core/Managers/OpenIddictAuthorizationManager.cs

@@ -896,7 +896,7 @@ public class OpenIddictAuthorizationManager<TAuthorization> : IOpenIddictAuthori
                     break;
                 }
 
-                if (scope.Contains(Separators.Space[0]))
+                if (scope.Contains(Separators.Space[0], StringComparison.Ordinal))
                 {
                     yield return new ValidationResult(SR.GetResourceString(SR.ID2042));
 

src/OpenIddict.Core/Managers/OpenIddictResourceManager.cs

@@ -12,6 +12,7 @@ using System.Text;
 using System.Text.Json;
 using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Options;
+using static System.Net.Mime.MediaTypeNames;
 using ValidationException = OpenIddict.Abstractions.OpenIddictExceptions.ValidationException;
 
 namespace OpenIddict.Core;
@@ -385,13 +386,7 @@ public class OpenIddictResourceManager<TResource> : IOpenIddictResourceManager w
     {
         ArgumentNullException.ThrowIfNull(resource);
 
-        var descriptions = await Store.GetDescriptionsAsync(resource, cancellationToken);
-        if (descriptions is not { Count: > 0 })
-        {
-            return ImmutableDictionary.Create<CultureInfo, string>();
-        }
-
-        return descriptions;
+        return await Store.GetDescriptionsAsync(resource, cancellationToken) is { IsEmpty: false } descriptions ? descriptions : [];
     }
 
     /// <summary>
@@ -424,13 +419,7 @@ public class OpenIddictResourceManager<TResource> : IOpenIddictResourceManager w
     {
         ArgumentNullException.ThrowIfNull(resource);
 
-        var names = await Store.GetDisplayNamesAsync(resource, cancellationToken);
-        if (names is not { Count: > 0 })
-        {
-            return ImmutableDictionary.Create<CultureInfo, string>();
-        }
-
-        return names;
+        return await Store.GetDisplayNamesAsync(resource, cancellationToken) is { IsEmpty: false } names ? names : [];
     }
 
     /// <summary>
@@ -880,7 +869,9 @@ public class OpenIddictResourceManager<TResource> : IOpenIddictResourceManager w
 
     /// <inheritdoc/>
     ValueTask<string?> IOpenIddictResourceManager.GetLocalizedDescriptionAsync(object resource, CancellationToken cancellationToken)
+#pragma warning disable MA0011
         => GetLocalizedDescriptionAsync((TResource) resource, cancellationToken);
+#pragma warning restore MA0011
 
     /// <inheritdoc/>
     ValueTask<string?> IOpenIddictResourceManager.GetLocalizedDescriptionAsync(object resource, CultureInfo culture, CancellationToken cancellationToken)
@@ -888,7 +879,9 @@ public class OpenIddictResourceManager<TResource> : IOpenIddictResourceManager w
 
     /// <inheritdoc/>
     ValueTask<string?> IOpenIddictResourceManager.GetLocalizedDisplayNameAsync(object resource, CancellationToken cancellationToken)
+#pragma warning disable MA0011
         => GetLocalizedDisplayNameAsync((TResource) resource, cancellationToken);
+#pragma warning restore MA0011
 
     /// <inheritdoc/>
     ValueTask<string?> IOpenIddictResourceManager.GetLocalizedDisplayNameAsync(object resource, CultureInfo culture, CancellationToken cancellationToken)

src/OpenIddict.Core/Managers/OpenIddictScopeManager.cs

@@ -424,13 +424,7 @@ public class OpenIddictScopeManager<TScope> : IOpenIddictScopeManager where TSco
     {
         ArgumentNullException.ThrowIfNull(scope);
 
-        var descriptions = await Store.GetDescriptionsAsync(scope, cancellationToken);
-        if (descriptions is not { Count: > 0 })
-        {
-            return ImmutableDictionary.Create<CultureInfo, string>();
-        }
-
-        return descriptions;
+        return await Store.GetDescriptionsAsync(scope, cancellationToken) is { IsEmpty: false } descriptions ? descriptions : [];
     }
 
     /// <summary>
@@ -463,13 +457,7 @@ public class OpenIddictScopeManager<TScope> : IOpenIddictScopeManager where TSco
     {
         ArgumentNullException.ThrowIfNull(scope);
 
-        var names = await Store.GetDisplayNamesAsync(scope, cancellationToken);
-        if (names is not { Count: > 0 })
-        {
-            return ImmutableDictionary.Create<CultureInfo, string>();
-        }
-
-        return names;
+        return await Store.GetDisplayNamesAsync(scope, cancellationToken) is { IsEmpty: false } names ? names : [];
     }
 
     /// <summary>
@@ -870,7 +858,7 @@ public class OpenIddictScopeManager<TScope> : IOpenIddictScopeManager where TSco
                 yield return new ValidationResult(SR.GetResourceString(SR.ID2044));
             }
 
-            else if (name.Contains(Separators.Space[0]))
+            else if (name.Contains(Separators.Space[0], StringComparison.Ordinal))
             {
                 yield return new ValidationResult(SR.GetResourceString(SR.ID2045));
             }
@@ -962,7 +950,9 @@ public class OpenIddictScopeManager<TScope> : IOpenIddictScopeManager where TSco
 
     /// <inheritdoc/>
     ValueTask<string?> IOpenIddictScopeManager.GetLocalizedDescriptionAsync(object scope, CancellationToken cancellationToken)
+#pragma warning disable MA0011
         => GetLocalizedDescriptionAsync((TScope) scope, cancellationToken);
+#pragma warning restore MA0011
 
     /// <inheritdoc/>
     ValueTask<string?> IOpenIddictScopeManager.GetLocalizedDescriptionAsync(object scope, CultureInfo culture, CancellationToken cancellationToken)
@@ -970,7 +960,9 @@ public class OpenIddictScopeManager<TScope> : IOpenIddictScopeManager where TSco
 
     /// <inheritdoc/>
     ValueTask<string?> IOpenIddictScopeManager.GetLocalizedDisplayNameAsync(object scope, CancellationToken cancellationToken)
+#pragma warning disable MA0011
         => GetLocalizedDisplayNameAsync((TScope) scope, cancellationToken);
+#pragma warning restore MA0011
 
     /// <inheritdoc/>
     ValueTask<string?> IOpenIddictScopeManager.GetLocalizedDisplayNameAsync(object scope, CultureInfo culture, CancellationToken cancellationToken)

src/OpenIddict.EntityFramework/Stores/OpenIddictEntityFrameworkApplicationStore.cs

@@ -352,7 +352,7 @@ public class OpenIddictEntityFrameworkApplicationStore<
 
         if (string.IsNullOrEmpty(application.DisplayNames))
         {
-            return new(ImmutableDictionary.Create<CultureInfo, string>());
+            return new([]);
         }
 
         // Note: parsing the stringified display names is an expensive operation.
@@ -498,7 +498,7 @@ public class OpenIddictEntityFrameworkApplicationStore<
 
         if (string.IsNullOrEmpty(application.Properties))
         {
-            return new(ImmutableDictionary.Create<string, JsonElement>());
+            return new([]);
         }
 
         // Note: parsing the stringified properties is an expensive operation.
@@ -510,7 +510,7 @@ public class OpenIddictEntityFrameworkApplicationStore<
                  .SetSlidingExpiration(TimeSpan.FromMinutes(1));
 
             using var document = JsonDocument.Parse(application.Properties);
-            var builder = ImmutableDictionary.CreateBuilder<string, JsonElement>();
+            var builder = ImmutableDictionary.CreateBuilder<string, JsonElement>(StringComparer.Ordinal);
 
             foreach (var property in document.RootElement.EnumerateObject())
             {
@@ -606,7 +606,7 @@ public class OpenIddictEntityFrameworkApplicationStore<
 
         if (string.IsNullOrEmpty(application.Settings))
         {
-            return new(ImmutableDictionary.Create<string, string>());
+            return new([]);
         }
 
         // Note: parsing the stringified settings is an expensive operation.
@@ -618,7 +618,7 @@ public class OpenIddictEntityFrameworkApplicationStore<
                  .SetSlidingExpiration(TimeSpan.FromMinutes(1));
 
             using var document = JsonDocument.Parse(application.Settings);
-            var builder = ImmutableDictionary.CreateBuilder<string, string>();
+            var builder = ImmutableDictionary.CreateBuilder<string, string>(StringComparer.Ordinal);
 
             foreach (var property in document.RootElement.EnumerateObject())
             {
@@ -1060,17 +1060,14 @@ public class OpenIddictEntityFrameworkApplicationStore<
             return (TKey?) (object?) identifier;
         }
 
-        else
-        {
-            var converter =
+        var converter =
 #if NET
-                TypeDescriptor.GetConverterFromRegisteredType(typeof(TKey));
+            TypeDescriptor.GetConverterFromRegisteredType(typeof(TKey));
 #else
-                TypeDescriptor.GetConverter(typeof(TKey));
+            TypeDescriptor.GetConverter(typeof(TKey));
 #endif
 
-            return (TKey?) converter.ConvertFromInvariantString(identifier);
-        }
+        return (TKey?) converter.ConvertFromInvariantString(identifier);
     }
 
     /// <summary>
@@ -1091,16 +1088,13 @@ public class OpenIddictEntityFrameworkApplicationStore<
             return value;
         }
 
-        else
-        {
-            var converter =
+        var converter =
 #if NET
-                TypeDescriptor.GetConverterFromRegisteredType(typeof(TKey));
+            TypeDescriptor.GetConverterFromRegisteredType(typeof(TKey));
 #else
-                TypeDescriptor.GetConverter(typeof(TKey));
+            TypeDescriptor.GetConverter(typeof(TKey));
 #endif
 
-            return converter.ConvertToInvariantString(identifier);
-        }
+        return converter.ConvertToInvariantString(identifier);
     }
 }

src/OpenIddict.EntityFramework/Stores/OpenIddictEntityFrameworkAuthorizationStore.cs

@@ -302,7 +302,7 @@ public class OpenIddictEntityFrameworkAuthorizationStore<
     {
         ArgumentNullException.ThrowIfNull(authorization);
 
-        return new(authorization.CreationDate is DateTime date ? DateTime.SpecifyKind(date, DateTimeKind.Utc) : null);
+        return new(authorization.CreationDate is DateTime date ? new DateTimeOffset(DateTime.SpecifyKind(date, DateTimeKind.Utc)) : null);
     }
 
     /// <inheritdoc/>
@@ -320,7 +320,7 @@ public class OpenIddictEntityFrameworkAuthorizationStore<
 
         if (string.IsNullOrEmpty(authorization.Properties))
         {
-            return new(ImmutableDictionary.Create<string, JsonElement>());
+            return new([]);
         }
 
         // Note: parsing the stringified properties is an expensive operation.
@@ -332,7 +332,7 @@ public class OpenIddictEntityFrameworkAuthorizationStore<
                  .SetSlidingExpiration(TimeSpan.FromMinutes(1));
 
             using var document = JsonDocument.Parse(authorization.Properties);
-            var builder = ImmutableDictionary.CreateBuilder<string, JsonElement>();
+            var builder = ImmutableDictionary.CreateBuilder<string, JsonElement>(StringComparer.Ordinal);
 
             foreach (var property in document.RootElement.EnumerateObject())
             {
@@ -894,17 +894,14 @@ public class OpenIddictEntityFrameworkAuthorizationStore<
             return (TKey?) (object?) identifier;
         }
 
-        else
-        {
-            var converter =
+        var converter =
 #if NET
-                TypeDescriptor.GetConverterFromRegisteredType(typeof(TKey));
+            TypeDescriptor.GetConverterFromRegisteredType(typeof(TKey));
 #else
-                TypeDescriptor.GetConverter(typeof(TKey));
+            TypeDescriptor.GetConverter(typeof(TKey));
 #endif
 
-            return (TKey?) converter.ConvertFromInvariantString(identifier);
-        }
+        return (TKey?) converter.ConvertFromInvariantString(identifier);
     }
 
     /// <summary>
@@ -925,16 +922,13 @@ public class OpenIddictEntityFrameworkAuthorizationStore<
             return value;
         }
 
-        else
-        {
-            var converter =
+        var converter =
 #if NET
-                TypeDescriptor.GetConverterFromRegisteredType(typeof(TKey));
+            TypeDescriptor.GetConverterFromRegisteredType(typeof(TKey));
 #else
-                TypeDescriptor.GetConverter(typeof(TKey));
+            TypeDescriptor.GetConverter(typeof(TKey));
 #endif
 
-            return converter.ConvertToInvariantString(identifier);
-        }
+        return converter.ConvertToInvariantString(identifier);
     }
 }

src/OpenIddict.EntityFramework/Stores/OpenIddictEntityFrameworkResourceStore.cs

@@ -210,7 +210,7 @@ public class OpenIddictEntityFrameworkResourceStore<
 
         if (string.IsNullOrEmpty(resource.Descriptions))
         {
-            return new(ImmutableDictionary.Create<CultureInfo, string>());
+            return new([]);
         }
 
         // Note: parsing the stringified descriptions is an expensive operation.
@@ -256,7 +256,7 @@ public class OpenIddictEntityFrameworkResourceStore<
 
         if (string.IsNullOrEmpty(resource.DisplayNames))
         {
-            return new(ImmutableDictionary.Create<CultureInfo, string>());
+            return new([]);
         }
 
         // Note: parsing the stringified display names is an expensive operation.
@@ -310,7 +310,7 @@ public class OpenIddictEntityFrameworkResourceStore<
 
         if (string.IsNullOrEmpty(resource.Properties))
         {
-            return new(ImmutableDictionary.Create<string, JsonElement>());
+            return new([]);
         }
 
         // Note: parsing the stringified properties is an expensive operation.
@@ -322,7 +322,7 @@ public class OpenIddictEntityFrameworkResourceStore<
                  .SetSlidingExpiration(TimeSpan.FromMinutes(1));
 
             using var document = JsonDocument.Parse(resource.Properties);
-            var builder = ImmutableDictionary.CreateBuilder<string, JsonElement>();
+            var builder = ImmutableDictionary.CreateBuilder<string, JsonElement>(StringComparer.Ordinal);
 
             foreach (var property in document.RootElement.EnumerateObject())
             {
@@ -579,17 +579,14 @@ public class OpenIddictEntityFrameworkResourceStore<
             return (TKey?) (object?) identifier;
         }
 
-        else
-        {
-            var converter =
+        var converter =
 #if NET
-                TypeDescriptor.GetConverterFromRegisteredType(typeof(TKey));
+            TypeDescriptor.GetConverterFromRegisteredType(typeof(TKey));
 #else
-                TypeDescriptor.GetConverter(typeof(TKey));
+            TypeDescriptor.GetConverter(typeof(TKey));
 #endif
 
-            return (TKey?) converter.ConvertFromInvariantString(identifier);
-        }
+        return (TKey?) converter.ConvertFromInvariantString(identifier);
     }
 
     /// <summary>
@@ -610,16 +607,13 @@ public class OpenIddictEntityFrameworkResourceStore<
             return value;
         }
 
-        else
-        {
-            var converter =
+        var converter =
 #if NET
-                TypeDescriptor.GetConverterFromRegisteredType(typeof(TKey));
+            TypeDescriptor.GetConverterFromRegisteredType(typeof(TKey));
 #else
-                TypeDescriptor.GetConverter(typeof(TKey));
+            TypeDescriptor.GetConverter(typeof(TKey));
 #endif
 
-            return converter.ConvertToInvariantString(identifier);
-        }
+        return converter.ConvertToInvariantString(identifier);
     }
 }

src/OpenIddict.EntityFramework/Stores/OpenIddictEntityFrameworkScopeStore.cs

@@ -242,7 +242,7 @@ public class OpenIddictEntityFrameworkScopeStore<
 
         if (string.IsNullOrEmpty(scope.Descriptions))
         {
-            return new(ImmutableDictionary.Create<CultureInfo, string>());
+            return new([]);
         }
 
         // Note: parsing the stringified descriptions is an expensive operation.
@@ -288,7 +288,7 @@ public class OpenIddictEntityFrameworkScopeStore<
 
         if (string.IsNullOrEmpty(scope.DisplayNames))
         {
-            return new(ImmutableDictionary.Create<CultureInfo, string>());
+            return new([]);
         }
 
         // Note: parsing the stringified display names is an expensive operation.
@@ -342,7 +342,7 @@ public class OpenIddictEntityFrameworkScopeStore<
 
         if (string.IsNullOrEmpty(scope.Properties))
         {
-            return new(ImmutableDictionary.Create<string, JsonElement>());
+            return new([]);
         }
 
         // Note: parsing the stringified properties is an expensive operation.
@@ -354,7 +354,7 @@ public class OpenIddictEntityFrameworkScopeStore<
                  .SetSlidingExpiration(TimeSpan.FromMinutes(1));
 
             using var document = JsonDocument.Parse(scope.Properties);
-            var builder = ImmutableDictionary.CreateBuilder<string, JsonElement>();
+            var builder = ImmutableDictionary.CreateBuilder<string, JsonElement>(StringComparer.Ordinal);
 
             foreach (var property in document.RootElement.EnumerateObject())
             {
@@ -683,17 +683,14 @@ public class OpenIddictEntityFrameworkScopeStore<
             return (TKey?) (object?) identifier;
         }
 
-        else
-        {
-            var converter =
+        var converter =
 #if NET
-                TypeDescriptor.GetConverterFromRegisteredType(typeof(TKey));
+            TypeDescriptor.GetConverterFromRegisteredType(typeof(TKey));
 #else
-                TypeDescriptor.GetConverter(typeof(TKey));
+            TypeDescriptor.GetConverter(typeof(TKey));
 #endif
 
-            return (TKey?) converter.ConvertFromInvariantString(identifier);
-        }
+        return (TKey?) converter.ConvertFromInvariantString(identifier);
     }
 
     /// <summary>
@@ -714,16 +711,13 @@ public class OpenIddictEntityFrameworkScopeStore<
             return value;
         }
 
-        else
-        {
-            var converter =
+        var converter =
 #if NET
-                TypeDescriptor.GetConverterFromRegisteredType(typeof(TKey));
+            TypeDescriptor.GetConverterFromRegisteredType(typeof(TKey));
 #else
-                TypeDescriptor.GetConverter(typeof(TKey));
+            TypeDescriptor.GetConverter(typeof(TKey));
 #endif
 
-            return converter.ConvertToInvariantString(identifier);
-        }
+        return converter.ConvertToInvariantString(identifier);
     }
 }

src/OpenIddict.EntityFramework/Stores/OpenIddictEntityFrameworkSessionStore.cs

@@ -343,7 +343,7 @@ public class OpenIddictEntityFrameworkSessionStore<
     {
         ArgumentNullException.ThrowIfNull(session);
 
-        return new(session.CreationDate is DateTime date ? DateTime.SpecifyKind(date, DateTimeKind.Utc) : null);
+        return new(session.CreationDate is DateTime date ? new DateTimeOffset(DateTime.SpecifyKind(date, DateTimeKind.Utc)) : null);
     }
 
     /// <inheritdoc/>
@@ -369,7 +369,7 @@ public class OpenIddictEntityFrameworkSessionStore<
 
         if (string.IsNullOrEmpty(session.Properties))
         {
-            return new(ImmutableDictionary.Create<string, JsonElement>());
+            return new([]);
         }
 
         // Note: parsing the stringified properties is an expensive operation.
@@ -381,7 +381,7 @@ public class OpenIddictEntityFrameworkSessionStore<
                  .SetSlidingExpiration(TimeSpan.FromMinutes(1));
 
             using var document = JsonDocument.Parse(session.Properties);
-            var builder = ImmutableDictionary.CreateBuilder<string, JsonElement>();
+            var builder = ImmutableDictionary.CreateBuilder<string, JsonElement>(StringComparer.Ordinal);
 
             foreach (var property in document.RootElement.EnumerateObject())
             {
@@ -660,17 +660,14 @@ public class OpenIddictEntityFrameworkSessionStore<
             return (TKey?) (object?) identifier;
         }
 
-        else
-        {
-            var converter =
+        var converter =
 #if NET
-                TypeDescriptor.GetConverterFromRegisteredType(typeof(TKey));
+            TypeDescriptor.GetConverterFromRegisteredType(typeof(TKey));
 #else
-                TypeDescriptor.GetConverter(typeof(TKey));
+            TypeDescriptor.GetConverter(typeof(TKey));
 #endif
 
-            return (TKey?) converter.ConvertFromInvariantString(identifier);
-        }
+        return (TKey?) converter.ConvertFromInvariantString(identifier);
     }
 
     /// <summary>
@@ -691,16 +688,13 @@ public class OpenIddictEntityFrameworkSessionStore<
             return value;
         }
 
-        else
-        {
-            var converter =
+        var converter =
 #if NET
-                TypeDescriptor.GetConverterFromRegisteredType(typeof(TKey));
+            TypeDescriptor.GetConverterFromRegisteredType(typeof(TKey));
 #else
-                TypeDescriptor.GetConverter(typeof(TKey));
+            TypeDescriptor.GetConverter(typeof(TKey));
 #endif
 
-            return converter.ConvertToInvariantString(identifier);
-        }
+        return converter.ConvertToInvariantString(identifier);
     }
 }

src/OpenIddict.EntityFramework/Stores/OpenIddictEntityFrameworkTokenStore.cs

@@ -342,7 +342,7 @@ public class OpenIddictEntityFrameworkTokenStore<
     {
         ArgumentNullException.ThrowIfNull(token);
 
-        return new(token.CreationDate is DateTime date ? DateTime.SpecifyKind(date, DateTimeKind.Utc) : null);
+        return new(token.CreationDate is DateTime date ? new DateTimeOffset(DateTime.SpecifyKind(date, DateTimeKind.Utc)) : null);
     }
 
     /// <inheritdoc/>
@@ -350,7 +350,7 @@ public class OpenIddictEntityFrameworkTokenStore<
     {
         ArgumentNullException.ThrowIfNull(token);
 
-        return new(token.ExpirationDate is DateTime date ? DateTime.SpecifyKind(date, DateTimeKind.Utc) : null);
+        return new(token.ExpirationDate is DateTime date ? new DateTimeOffset(DateTime.SpecifyKind(date, DateTimeKind.Utc)) : null);
     }
 
     /// <inheritdoc/>
@@ -376,7 +376,7 @@ public class OpenIddictEntityFrameworkTokenStore<
 
         if (string.IsNullOrEmpty(token.Properties))
         {
-            return new(ImmutableDictionary.Create<string, JsonElement>());
+            return new([]);
         }
 
         // Note: parsing the stringified properties is an expensive operation.
@@ -388,7 +388,7 @@ public class OpenIddictEntityFrameworkTokenStore<
                  .SetSlidingExpiration(TimeSpan.FromMinutes(1));
 
             using var document = JsonDocument.Parse(token.Properties);
-            var builder = ImmutableDictionary.CreateBuilder<string, JsonElement>();
+            var builder = ImmutableDictionary.CreateBuilder<string, JsonElement>(StringComparer.Ordinal);
 
             foreach (var property in document.RootElement.EnumerateObject())
             {
@@ -406,7 +406,7 @@ public class OpenIddictEntityFrameworkTokenStore<
     {
         ArgumentNullException.ThrowIfNull(token);
 
-        return new(token.RedemptionDate is DateTime date ? DateTime.SpecifyKind(date, DateTimeKind.Utc) : null);
+        return new(token.RedemptionDate is DateTime date ? new DateTimeOffset(DateTime.SpecifyKind(date, DateTimeKind.Utc)) : null);
     }
 
     /// <inheritdoc/>
@@ -1016,17 +1016,14 @@ public class OpenIddictEntityFrameworkTokenStore<
             return (TKey?) (object?) identifier;
         }
 
-        else
-        {
-            var converter =
+        var converter =
 #if NET
-                TypeDescriptor.GetConverterFromRegisteredType(typeof(TKey));
+            TypeDescriptor.GetConverterFromRegisteredType(typeof(TKey));
 #else
-                TypeDescriptor.GetConverter(typeof(TKey));
+            TypeDescriptor.GetConverter(typeof(TKey));
 #endif
 
-            return (TKey?) converter.ConvertFromInvariantString(identifier);
-        }
+        return (TKey?) converter.ConvertFromInvariantString(identifier);
     }
 
     /// <summary>
@@ -1047,16 +1044,13 @@ public class OpenIddictEntityFrameworkTokenStore<
             return value;
         }
 
-        else
-        {
-            var converter =
+        var converter =
 #if NET
-                TypeDescriptor.GetConverterFromRegisteredType(typeof(TKey));
+            TypeDescriptor.GetConverterFromRegisteredType(typeof(TKey));
 #else
-                TypeDescriptor.GetConverter(typeof(TKey));
+            TypeDescriptor.GetConverter(typeof(TKey));
 #endif
 
-            return converter.ConvertToInvariantString(identifier);
-        }
+        return converter.ConvertToInvariantString(identifier);
     }
 }

src/OpenIddict.EntityFrameworkCore/Stores/OpenIddictEntityFrameworkCoreApplicationStore.cs

@@ -587,7 +587,7 @@ public class OpenIddictEntityFrameworkCoreApplicationStore<
         ArgumentNullException.ThrowIfNull(application);
 
         application.DisplayNames = names is { IsEmpty: false }
-            ? names.ToImmutableDictionary(static pair => pair.Key.Name, static pair => pair.Value)
+            ? names.ToImmutableDictionary(static pair => pair.Key.Name, static pair => pair.Value, StringComparer.Ordinal)
             : null;
 
         return ValueTask.CompletedTask;
@@ -714,12 +714,9 @@ public class OpenIddictEntityFrameworkCoreApplicationStore<
             return (TKey?) (object?) identifier;
         }
 
-        else
-        {
-            var converter = TypeDescriptor.GetConverterFromRegisteredType(typeof(TKey));
+        var converter = TypeDescriptor.GetConverterFromRegisteredType(typeof(TKey));
 
-            return (TKey?) converter.ConvertFromInvariantString(identifier);
-        }
+        return (TKey?) converter.ConvertFromInvariantString(identifier);
     }
 
     /// <summary>
@@ -740,12 +737,9 @@ public class OpenIddictEntityFrameworkCoreApplicationStore<
             return value;
         }
 
-        else
-        {
-            var converter = TypeDescriptor.GetConverterFromRegisteredType(typeof(TKey));
+        var converter = TypeDescriptor.GetConverterFromRegisteredType(typeof(TKey));
 
-            return converter.ConvertToInvariantString(identifier);
-        }
+        return converter.ConvertToInvariantString(identifier);
     }
 
     /// <summary>

src/OpenIddict.EntityFrameworkCore/Stores/OpenIddictEntityFrameworkCoreAuthorizationStore.cs

@@ -361,7 +361,7 @@ public class OpenIddictEntityFrameworkCoreAuthorizationStore<
     {
         ArgumentNullException.ThrowIfNull(authorization);
 
-        return new(authorization.CreationDate is DateTime date ? DateTime.SpecifyKind(date, DateTimeKind.Utc) : null);
+        return new(authorization.CreationDate is DateTime date ? new DateTimeOffset(DateTime.SpecifyKind(date, DateTimeKind.Utc)) : null);
     }
 
     /// <inheritdoc/>
@@ -931,12 +931,9 @@ public class OpenIddictEntityFrameworkCoreAuthorizationStore<
             return (TKey?) (object?) identifier;
         }
 
-        else
-        {
-            var converter = TypeDescriptor.GetConverterFromRegisteredType(typeof(TKey));
+        var converter = TypeDescriptor.GetConverterFromRegisteredType(typeof(TKey));
 
-            return (TKey?) converter.ConvertFromInvariantString(identifier);
-        }
+        return (TKey?) converter.ConvertFromInvariantString(identifier);
     }
 
     /// <summary>
@@ -957,12 +954,9 @@ public class OpenIddictEntityFrameworkCoreAuthorizationStore<
             return value;
         }
 
-        else
-        {
-            var converter = TypeDescriptor.GetConverterFromRegisteredType(typeof(TKey));
+        var converter = TypeDescriptor.GetConverterFromRegisteredType(typeof(TKey));
 
-            return converter.ConvertToInvariantString(identifier);
-        }
+        return converter.ConvertToInvariantString(identifier);
     }
 
     /// <summary>

src/OpenIddict.EntityFrameworkCore/Stores/OpenIddictEntityFrameworkCoreResourceStore.cs

@@ -334,7 +334,7 @@ public class OpenIddictEntityFrameworkCoreResourceStore<
         ArgumentNullException.ThrowIfNull(resource);
 
         resource.Descriptions = descriptions is { IsEmpty: false }
-            ? descriptions.ToImmutableDictionary(static pair => pair.Key.Name, static pair => pair.Value)
+            ? descriptions.ToImmutableDictionary(static pair => pair.Key.Name, static pair => pair.Value, StringComparer.Ordinal)
             : null;
 
         return ValueTask.CompletedTask;
@@ -357,7 +357,7 @@ public class OpenIddictEntityFrameworkCoreResourceStore<
         ArgumentNullException.ThrowIfNull(resource);
 
         resource.DisplayNames = names is { IsEmpty: false }
-            ? names.ToImmutableDictionary(static pair => pair.Key.Name, static pair => pair.Value)
+            ? names.ToImmutableDictionary(static pair => pair.Key.Name, static pair => pair.Value, StringComparer.Ordinal)
             : null;
 
         return ValueTask.CompletedTask;
@@ -431,12 +431,9 @@ public class OpenIddictEntityFrameworkCoreResourceStore<
             return (TKey?) (object?) identifier;
         }
 
-        else
-        {
-            var converter = TypeDescriptor.GetConverterFromRegisteredType(typeof(TKey));
+        var converter = TypeDescriptor.GetConverterFromRegisteredType(typeof(TKey));
 
-            return (TKey?) converter.ConvertFromInvariantString(identifier);
-        }
+        return (TKey?) converter.ConvertFromInvariantString(identifier);
     }
 
     /// <summary>
@@ -457,11 +454,8 @@ public class OpenIddictEntityFrameworkCoreResourceStore<
             return value;
         }
 
-        else
-        {
-            var converter = TypeDescriptor.GetConverterFromRegisteredType(typeof(TKey));
+        var converter = TypeDescriptor.GetConverterFromRegisteredType(typeof(TKey));
 
-            return converter.ConvertToInvariantString(identifier);
-        }
+        return converter.ConvertToInvariantString(identifier);
     }
 }

src/OpenIddict.EntityFrameworkCore/Stores/OpenIddictEntityFrameworkCoreScopeStore.cs

@@ -233,7 +233,7 @@ public class OpenIddictEntityFrameworkCoreScopeStore<
 
         return new(scope.Descriptions is { Count: > 0 } descriptions
             ? descriptions.ToImmutableDictionary(static pair => CultureInfo.GetCultureInfo(pair.Key), static pair => pair.Value)
-            : ImmutableDictionary.Create<CultureInfo, string>());
+            : []);
     }
 
     /// <inheritdoc/>
@@ -362,7 +362,7 @@ public class OpenIddictEntityFrameworkCoreScopeStore<
         ArgumentNullException.ThrowIfNull(scope);
 
         scope.Descriptions = descriptions is { IsEmpty: false }
-            ? descriptions.ToImmutableDictionary(static pair => pair.Key.Name, static pair => pair.Value)
+            ? descriptions.ToImmutableDictionary(static pair => pair.Key.Name, static pair => pair.Value, StringComparer.Ordinal)
             : null;
 
         return ValueTask.CompletedTask;
@@ -385,7 +385,7 @@ public class OpenIddictEntityFrameworkCoreScopeStore<
         ArgumentNullException.ThrowIfNull(scope);
 
         scope.DisplayNames = names is { IsEmpty: false }
-            ? names.ToImmutableDictionary(static pair => pair.Key.Name, static pair => pair.Value)
+            ? names.ToImmutableDictionary(static pair => pair.Key.Name, static pair => pair.Value, StringComparer.Ordinal)
             : null;
 
         return ValueTask.CompletedTask;
@@ -469,12 +469,9 @@ public class OpenIddictEntityFrameworkCoreScopeStore<
             return (TKey?) (object?) identifier;
         }
 
-        else
-        {
-            var converter = TypeDescriptor.GetConverterFromRegisteredType(typeof(TKey));
+        var converter = TypeDescriptor.GetConverterFromRegisteredType(typeof(TKey));
 
-            return (TKey?) converter.ConvertFromInvariantString(identifier);
-        }
+        return (TKey?) converter.ConvertFromInvariantString(identifier);
     }
 
     /// <summary>
@@ -495,11 +492,8 @@ public class OpenIddictEntityFrameworkCoreScopeStore<
             return value;
         }
 
-        else
-        {
-            var converter = TypeDescriptor.GetConverterFromRegisteredType(typeof(TKey));
+        var converter = TypeDescriptor.GetConverterFromRegisteredType(typeof(TKey));
 
-            return converter.ConvertToInvariantString(identifier);
-        }
+        return converter.ConvertToInvariantString(identifier);
     }
 }

src/OpenIddict.EntityFrameworkCore/Stores/OpenIddictEntityFrameworkCoreSessionStore.cs

@@ -364,7 +364,7 @@ public class OpenIddictEntityFrameworkCoreSessionStore<
     {
         ArgumentNullException.ThrowIfNull(session);
 
-        return new(session.CreationDate is DateTime date ? DateTime.SpecifyKind(date, DateTimeKind.Utc) : null);
+        return new(session.CreationDate is DateTime date ? new DateTimeOffset(DateTime.SpecifyKind(date, DateTimeKind.Utc)) : null);
     }
 
     /// <inheritdoc/>
@@ -632,12 +632,9 @@ public class OpenIddictEntityFrameworkCoreSessionStore<
             return (TKey?) (object?) identifier;
         }
 
-        else
-        {
-            var converter = TypeDescriptor.GetConverterFromRegisteredType(typeof(TKey));
+        var converter = TypeDescriptor.GetConverterFromRegisteredType(typeof(TKey));
 
-            return (TKey?) converter.ConvertFromInvariantString(identifier);
-        }
+        return (TKey?) converter.ConvertFromInvariantString(identifier);
     }
 
     /// <summary>
@@ -658,11 +655,8 @@ public class OpenIddictEntityFrameworkCoreSessionStore<
             return value;
         }
 
-        else
-        {
-            var converter = TypeDescriptor.GetConverterFromRegisteredType(typeof(TKey));
+        var converter = TypeDescriptor.GetConverterFromRegisteredType(typeof(TKey));
 
-            return converter.ConvertToInvariantString(identifier);
-        }
+        return converter.ConvertToInvariantString(identifier);
     }
 }

src/OpenIddict.EntityFrameworkCore/Stores/OpenIddictEntityFrameworkCoreTokenStore.cs

@@ -358,7 +358,7 @@ public class OpenIddictEntityFrameworkCoreTokenStore<
     {
         ArgumentNullException.ThrowIfNull(token);
 
-        return new(token.CreationDate is DateTime date ? DateTime.SpecifyKind(date, DateTimeKind.Utc) : null);
+        return new(token.CreationDate is DateTime date ? new DateTimeOffset(DateTime.SpecifyKind(date, DateTimeKind.Utc)) : null);
     }
 
     /// <inheritdoc/>
@@ -366,7 +366,7 @@ public class OpenIddictEntityFrameworkCoreTokenStore<
     {
         ArgumentNullException.ThrowIfNull(token);
 
-        return new(token.ExpirationDate is DateTime date ? DateTime.SpecifyKind(date, DateTimeKind.Utc) : null);
+        return new(token.ExpirationDate is DateTime date ? new DateTimeOffset(DateTime.SpecifyKind(date, DateTimeKind.Utc)) : null);
     }
 
     /// <inheritdoc/>
@@ -398,7 +398,7 @@ public class OpenIddictEntityFrameworkCoreTokenStore<
     {
         ArgumentNullException.ThrowIfNull(token);
 
-        return new(token.RedemptionDate is DateTime date ? DateTime.SpecifyKind(date, DateTimeKind.Utc) : null);
+        return new(token.RedemptionDate is DateTime date ? new DateTimeOffset(DateTime.SpecifyKind(date, DateTimeKind.Utc)) : null);
     }
 
     /// <inheritdoc/>
@@ -1080,12 +1080,9 @@ public class OpenIddictEntityFrameworkCoreTokenStore<
             return (TKey?) (object?) identifier;
         }
 
-        else
-        {
-            var converter = TypeDescriptor.GetConverterFromRegisteredType(typeof(TKey));
+        var converter = TypeDescriptor.GetConverterFromRegisteredType(typeof(TKey));
 
-            return (TKey?) converter.ConvertFromInvariantString(identifier);
-        }
+        return (TKey?) converter.ConvertFromInvariantString(identifier);
     }
 
     /// <summary>
@@ -1106,12 +1103,9 @@ public class OpenIddictEntityFrameworkCoreTokenStore<
             return value;
         }
 
-        else
-        {
-            var converter = TypeDescriptor.GetConverterFromRegisteredType(typeof(TKey));
+        var converter = TypeDescriptor.GetConverterFromRegisteredType(typeof(TKey));
 
-            return converter.ConvertToInvariantString(identifier);
-        }
+        return converter.ConvertToInvariantString(identifier);
     }
 
     /// <summary>

src/OpenIddict.MongoDb.Models/OpenIddictMongoDbSession.cs

@@ -11,7 +11,7 @@ namespace OpenIddict.MongoDb.Models;
 /// <summary>
 /// Represents an OpenIddict session.
 /// </summary>
-[DebuggerDisplay("Id = {Id.ToString(),nq} ; Name = {Name,nq}")]
+[DebuggerDisplay("Id = {Id.ToString(),nq} ; Subject = {Subject,nq} ; LoginId = {LoginId,nq} ; Status = {Status,nq}")]
 public class OpenIddictMongoDbSession
 {
     /// <summary>

src/OpenIddict.MongoDb/Stores/OpenIddictMongoDbApplicationStore.cs

@@ -291,11 +291,11 @@ public class OpenIddictMongoDbApplicationStore<
 
         if (application.Properties is null)
         {
-            return new(ImmutableDictionary.Create<string, JsonElement>());
+            return new([]);
         }
 
         using var document = JsonDocument.Parse(application.Properties.ToJson());
-        var builder = ImmutableDictionary.CreateBuilder<string, JsonElement>();
+        var builder = ImmutableDictionary.CreateBuilder<string, JsonElement>(StringComparer.Ordinal);
 
         foreach (var property in document.RootElement.EnumerateObject())
         {
@@ -464,7 +464,7 @@ public class OpenIddictMongoDbApplicationStore<
         ArgumentNullException.ThrowIfNull(application);
 
         application.DisplayNames = names is { Count: > 0 }
-            ? names.ToImmutableDictionary(static pair => pair.Key.Name, static pair => pair.Value)
+            ? names.ToImmutableDictionary(static pair => pair.Key.Name, static pair => pair.Value, StringComparer.Ordinal)
             : null;
 
         return ValueTask.CompletedTask;

src/OpenIddict.MongoDb/Stores/OpenIddictMongoDbAuthorizationStore.cs

@@ -229,7 +229,7 @@ public class OpenIddictMongoDbAuthorizationStore<
     {
         ArgumentNullException.ThrowIfNull(authorization);
 
-        return new(authorization.CreationDate is DateTime date ? DateTime.SpecifyKind(date, DateTimeKind.Utc) : null);
+        return new(authorization.CreationDate is DateTime date ? new DateTimeOffset(DateTime.SpecifyKind(date, DateTimeKind.Utc)) : null);
     }
 
     /// <inheritdoc/>
@@ -247,11 +247,11 @@ public class OpenIddictMongoDbAuthorizationStore<
 
         if (authorization.Properties is null)
         {
-            return new(ImmutableDictionary.Create<string, JsonElement>());
+            return new([]);
         }
 
         using var document = JsonDocument.Parse(authorization.Properties.ToJson());
-        var builder = ImmutableDictionary.CreateBuilder<string, JsonElement>();
+        var builder = ImmutableDictionary.CreateBuilder<string, JsonElement>(StringComparer.Ordinal);
 
         foreach (var property in document.RootElement.EnumerateObject())
         {

src/OpenIddict.MongoDb/Stores/OpenIddictMongoDbResourceStore.cs

@@ -221,11 +221,11 @@ public class OpenIddictMongoDbResourceStore<
 
         if (resource.Properties is null)
         {
-            return new(ImmutableDictionary.Create<string, JsonElement>());
+            return new([]);
         }
 
         using var document = JsonDocument.Parse(resource.Properties.ToJson());
-        var builder = ImmutableDictionary.CreateBuilder<string, JsonElement>();
+        var builder = ImmutableDictionary.CreateBuilder<string, JsonElement>(StringComparer.Ordinal);
 
         foreach (var property in document.RootElement.EnumerateObject())
         {
@@ -313,7 +313,7 @@ public class OpenIddictMongoDbResourceStore<
         ArgumentNullException.ThrowIfNull(resource);
 
         resource.Descriptions = descriptions is { Count: > 0 }
-            ? descriptions.ToImmutableDictionary(static pair => pair.Key.Name, static pair => pair.Value)
+            ? descriptions.ToImmutableDictionary(static pair => pair.Key.Name, static pair => pair.Value, StringComparer.Ordinal)
             : null;
 
         return ValueTask.CompletedTask;
@@ -326,7 +326,7 @@ public class OpenIddictMongoDbResourceStore<
         ArgumentNullException.ThrowIfNull(resource);
 
         resource.DisplayNames = names is { Count: > 0 }
-            ? names.ToImmutableDictionary(static pair => pair.Key.Name, static pair => pair.Value)
+            ? names.ToImmutableDictionary(static pair => pair.Key.Name, static pair => pair.Value, StringComparer.Ordinal)
             : null;
 
         return ValueTask.CompletedTask;

src/OpenIddict.MongoDb/Stores/OpenIddictMongoDbScopeStore.cs

@@ -240,11 +240,11 @@ public class OpenIddictMongoDbScopeStore<
 
         if (scope.Properties is null)
         {
-            return new(ImmutableDictionary.Create<string, JsonElement>());
+            return new([]);
         }
 
         using var document = JsonDocument.Parse(scope.Properties.ToJson());
-        var builder = ImmutableDictionary.CreateBuilder<string, JsonElement>();
+        var builder = ImmutableDictionary.CreateBuilder<string, JsonElement>(StringComparer.Ordinal);
 
         foreach (var property in document.RootElement.EnumerateObject())
         {
@@ -340,7 +340,7 @@ public class OpenIddictMongoDbScopeStore<
         ArgumentNullException.ThrowIfNull(scope);
 
         scope.Descriptions = descriptions is { Count: > 0 }
-            ? descriptions.ToImmutableDictionary(static pair => pair.Key.Name, static pair => pair.Value)
+            ? descriptions.ToImmutableDictionary(static pair => pair.Key.Name, static pair => pair.Value, StringComparer.Ordinal)
             : null;
 
         return ValueTask.CompletedTask;
@@ -353,7 +353,7 @@ public class OpenIddictMongoDbScopeStore<
         ArgumentNullException.ThrowIfNull(scope);
 
         scope.DisplayNames = names is { Count: > 0 }
-            ? names.ToImmutableDictionary(static pair => pair.Key.Name, static pair => pair.Value)
+            ? names.ToImmutableDictionary(static pair => pair.Key.Name, static pair => pair.Value, StringComparer.Ordinal)
             : null;
 
         return ValueTask.CompletedTask;

src/OpenIddict.MongoDb/Stores/OpenIddictMongoDbSessionStore.cs

@@ -263,7 +263,7 @@ public class OpenIddictMongoDbSessionStore<
     {
         ArgumentNullException.ThrowIfNull(session);
 
-        return new(session.CreationDate is DateTime date ? DateTime.SpecifyKind(date, DateTimeKind.Utc) : null);
+        return new(session.CreationDate is DateTime date ? new DateTimeOffset(DateTime.SpecifyKind(date, DateTimeKind.Utc)) : null);
     }
 
     /// <inheritdoc/>
@@ -289,11 +289,11 @@ public class OpenIddictMongoDbSessionStore<
 
         if (session.Properties is null)
         {
-            return new(ImmutableDictionary.Create<string, JsonElement>());
+            return new([]);
         }
 
         using var document = JsonDocument.Parse(session.Properties.ToJson());
-        var builder = ImmutableDictionary.CreateBuilder<string, JsonElement>();
+        var builder = ImmutableDictionary.CreateBuilder<string, JsonElement>(StringComparer.Ordinal);
 
         foreach (var property in document.RootElement.EnumerateObject())
         {

src/OpenIddict.MongoDb/Stores/OpenIddictMongoDbTokenStore.cs

@@ -255,7 +255,7 @@ public class OpenIddictMongoDbTokenStore<
     {
         ArgumentNullException.ThrowIfNull(token);
 
-        return new(token.CreationDate is DateTime date ? DateTime.SpecifyKind(date, DateTimeKind.Utc) : null);
+        return new(token.CreationDate is DateTime date ? new DateTimeOffset(DateTime.SpecifyKind(date, DateTimeKind.Utc)) : null);
     }
 
     /// <inheritdoc/>
@@ -263,7 +263,7 @@ public class OpenIddictMongoDbTokenStore<
     {
         ArgumentNullException.ThrowIfNull(token);
 
-        return new(token.ExpirationDate is DateTime date ? DateTime.SpecifyKind(date, DateTimeKind.Utc) : null);
+        return new(token.ExpirationDate is DateTime date ? new DateTimeOffset(DateTime.SpecifyKind(date, DateTimeKind.Utc)) : null);
     }
 
     /// <inheritdoc/>
@@ -289,11 +289,11 @@ public class OpenIddictMongoDbTokenStore<
 
         if (token.Properties is null)
         {
-            return new(ImmutableDictionary.Create<string, JsonElement>());
+            return new([]);
         }
 
         using var document = JsonDocument.Parse(token.Properties.ToJson());
-        var builder = ImmutableDictionary.CreateBuilder<string, JsonElement>();
+        var builder = ImmutableDictionary.CreateBuilder<string, JsonElement>(StringComparer.Ordinal);
 
         foreach (var property in document.RootElement.EnumerateObject())
         {
@@ -308,7 +308,7 @@ public class OpenIddictMongoDbTokenStore<
     {
         ArgumentNullException.ThrowIfNull(token);
 
-        return new(token.RedemptionDate is DateTime date ? DateTime.SpecifyKind(date, DateTimeKind.Utc) : null);
+        return new(token.RedemptionDate is DateTime date ? new DateTimeOffset(DateTime.SpecifyKind(date, DateTimeKind.Utc)) : null);
     }
 
     /// <inheritdoc/>

src/OpenIddict.Server.AspNetCore/OpenIddictServerAspNetCoreHandler.cs

@@ -76,12 +76,12 @@ public sealed class OpenIddictServerAspNetCoreHandler : AuthenticationHandler<Au
             return true;
         }
 
-        else if (context.IsRequestSkipped)
+        if (context.IsRequestSkipped)
         {
             return false;
         }
 
-        else if (context.IsRejected)
+        if (context.IsRejected)
         {
             var notification = new ProcessErrorContext(transaction)
             {
@@ -98,7 +98,7 @@ public sealed class OpenIddictServerAspNetCoreHandler : AuthenticationHandler<Au
                 return true;
             }
 
-            else if (notification.IsRequestSkipped)
+            if (notification.IsRequestSkipped)
             {
                 return false;
             }
@@ -133,7 +133,7 @@ public sealed class OpenIddictServerAspNetCoreHandler : AuthenticationHandler<Au
             return AuthenticateResult.NoResult();
         }
 
-        else if (context.IsRejected)
+        if (context.IsRejected)
         {
             // Note: the missing_token error is special-cased to indicate to ASP.NET Core
             // that no authentication result could be produced due to the lack of token.
@@ -405,7 +405,7 @@ public sealed class OpenIddictServerAspNetCoreHandler : AuthenticationHandler<Au
             return;
         }
 
-        else if (context.IsRejected)
+        if (context.IsRejected)
         {
             var notification = new ProcessErrorContext(transaction)
             {
@@ -453,7 +453,7 @@ public sealed class OpenIddictServerAspNetCoreHandler : AuthenticationHandler<Au
             return;
         }
 
-        else if (context.IsRejected)
+        if (context.IsRejected)
         {
             var notification = new ProcessErrorContext(transaction)
             {
@@ -494,7 +494,7 @@ public sealed class OpenIddictServerAspNetCoreHandler : AuthenticationHandler<Au
             return;
         }
 
-        else if (context.IsRejected)
+        if (context.IsRejected)
         {
             var notification = new ProcessErrorContext(transaction)
             {

src/OpenIddict.Server.AspNetCore/OpenIddictServerAspNetCoreHandlers.cs

@@ -768,7 +768,7 @@ public static partial class OpenIddictServerAspNetCoreHandlers
                 var value = header["Basic ".Length..].Trim();
                 var data = Encoding.ASCII.GetString(Convert.FromBase64String(value));
 
-                var index = data.IndexOf(':');
+                var index = data.IndexOf(':', StringComparison.Ordinal);
                 if (index is < 0)
                 {
                     context.Reject(
@@ -803,7 +803,7 @@ public static partial class OpenIddictServerAspNetCoreHandlers
                     return null;
                 }
 
-                return Uri.UnescapeDataString(data.Replace("+", "%20"));
+                return Uri.UnescapeDataString(data.Replace("+", "%20", StringComparison.Ordinal));
             }
         }
     }
@@ -1102,7 +1102,7 @@ public static partial class OpenIddictServerAspNetCoreHandlers
                 builder.Append(parameter.Key);
                 builder.Append('=');
                 builder.Append('"');
-                builder.Append(parameter.Value.Replace("\"", "\\\""));
+                builder.Append(parameter.Value.Replace("\"", "\\\"", StringComparison.Ordinal));
                 builder.Append('"');
                 builder.Append(',');
             }

src/OpenIddict.Server.DataProtection/OpenIddictServerDataProtectionFormatter.cs

@@ -192,7 +192,7 @@ public sealed class OpenIddictServerDataProtectionFormatter : IOpenIddictServerD
         ArgumentNullException.ThrowIfNull(writer);
         ArgumentNullException.ThrowIfNull(principal);
 
-        var properties = new Dictionary<string, string>();
+        var properties = new Dictionary<string, string>(StringComparer.Ordinal);
 
         // Unlike ASP.NET Core Data Protection-based tokens, tokens serialized using the new format
         // can't include authentication properties. To ensure tokens can be used with previous versions

src/OpenIddict.Server.Owin/OpenIddictServerOwinHandler.cs

@@ -86,12 +86,12 @@ public sealed class OpenIddictServerOwinHandler : AuthenticationHandler<Authenti
             return true;
         }
 
-        else if (context.IsRequestSkipped)
+        if (context.IsRequestSkipped)
         {
             return false;
         }
 
-        else if (context.IsRejected)
+        if (context.IsRejected)
         {
             var notification = new ProcessErrorContext(transaction)
             {
@@ -108,7 +108,7 @@ public sealed class OpenIddictServerOwinHandler : AuthenticationHandler<Authenti
                 return true;
             }
 
-            else if (notification.IsRequestSkipped)
+            if (notification.IsRequestSkipped)
             {
                 return false;
             }
@@ -143,7 +143,7 @@ public sealed class OpenIddictServerOwinHandler : AuthenticationHandler<Authenti
             return null;
         }
 
-        else if (context.IsRejected)
+        if (context.IsRejected)
         {
             // Note: the missing_token error is special-cased to indicate to Katana
             // that no authentication result could be produced due to the lack of token.
@@ -302,7 +302,7 @@ public sealed class OpenIddictServerOwinHandler : AuthenticationHandler<Authenti
                 return;
             }
 
-            else if (context.IsRejected)
+            if (context.IsRejected)
             {
                 var notification = new ProcessErrorContext(transaction)
                 {
@@ -344,7 +344,7 @@ public sealed class OpenIddictServerOwinHandler : AuthenticationHandler<Authenti
                 return;
             }
 
-            else if (context.IsRejected)
+            if (context.IsRejected)
             {
                 var notification = new ProcessErrorContext(transaction)
                 {
@@ -385,7 +385,7 @@ public sealed class OpenIddictServerOwinHandler : AuthenticationHandler<Authenti
                 return;
             }
 
-            else if (context.IsRejected)
+            if (context.IsRejected)
             {
                 var notification = new ProcessErrorContext(transaction)
                 {

src/OpenIddict.Server.Owin/OpenIddictServerOwinHandlers.cs

@@ -845,7 +845,7 @@ public static partial class OpenIddictServerOwinHandlers
                 var value = header["Basic ".Length..].Trim();
                 var data = Encoding.ASCII.GetString(Convert.FromBase64String(value));
 
-                var index = data.IndexOf(':');
+                var index = data.IndexOf(':', StringComparison.Ordinal);
                 if (index is < 0)
                 {
                     context.Reject(
@@ -880,7 +880,7 @@ public static partial class OpenIddictServerOwinHandlers
                     return null;
                 }
 
-                return Uri.UnescapeDataString(data.Replace("+", "%20"));
+                return Uri.UnescapeDataString(data.Replace("+", "%20", StringComparison.Ordinal));
             }
         }
     }
@@ -1293,7 +1293,7 @@ public static partial class OpenIddictServerOwinHandlers
                 builder.Append(parameter.Key);
                 builder.Append('=');
                 builder.Append('"');
-                builder.Append(parameter.Value.Replace("\"", "\\\""));
+                builder.Append(parameter.Value.Replace("\"", "\\\"", StringComparison.Ordinal));
                 builder.Append('"');
                 builder.Append(',');
             }

src/OpenIddict.Server/OpenIddictServerHandlers.Authentication.cs

@@ -154,13 +154,13 @@ public static partial class OpenIddictServerHandlers
                     return;
                 }
 
-                else if (notification.IsRequestSkipped)
+                if (notification.IsRequestSkipped)
                 {
                     context.SkipRequest();
                     return;
                 }
 
-                else if (notification.IsRejected)
+                if (notification.IsRejected)
                 {
                     context.Reject(
                         error: notification.Error ?? Errors.InvalidRequest,
@@ -217,13 +217,13 @@ public static partial class OpenIddictServerHandlers
                     return;
                 }
 
-                else if (notification.IsRequestSkipped)
+                if (notification.IsRequestSkipped)
                 {
                     context.SkipRequest();
                     return;
                 }
 
-                else if (notification.IsRejected)
+                if (notification.IsRejected)
                 {
                     context.Reject(
                         error: notification.Error ?? Errors.InvalidRequest,
@@ -276,13 +276,13 @@ public static partial class OpenIddictServerHandlers
                     return;
                 }
 
-                else if (notification.IsRequestSkipped)
+                if (notification.IsRequestSkipped)
                 {
                     context.SkipRequest();
                     return;
                 }
 
-                else if (notification.IsRejected)
+                if (notification.IsRejected)
                 {
                     context.Reject(
                         error: notification.Error ?? Errors.InvalidRequest,
@@ -315,13 +315,13 @@ public static partial class OpenIddictServerHandlers
                         return;
                     }
 
-                    else if (@event.IsRequestSkipped)
+                    if (@event.IsRequestSkipped)
                     {
                         context.SkipRequest();
                         return;
                     }
 
-                    else if (@event.IsRejected)
+                    if (@event.IsRejected)
                     {
                         context.Reject(
                             error: @event.Error ?? Errors.InvalidRequest,
@@ -356,13 +356,13 @@ public static partial class OpenIddictServerHandlers
                         return;
                     }
 
-                    else if (@event.IsRequestSkipped)
+                    if (@event.IsRequestSkipped)
                     {
                         context.SkipRequest();
                         return;
                     }
 
-                    else if (@event.IsRejected)
+                    if (@event.IsRejected)
                     {
                         context.Reject(
                             error: notification.Error ?? Errors.InvalidRequest,
@@ -411,7 +411,7 @@ public static partial class OpenIddictServerHandlers
                     return;
                 }
 
-                else if (notification.IsRequestSkipped)
+                if (notification.IsRequestSkipped)
                 {
                     context.SkipRequest();
                     return;
@@ -605,13 +605,13 @@ public static partial class OpenIddictServerHandlers
                     return;
                 }
 
-                else if (notification.IsRequestSkipped)
+                if (notification.IsRequestSkipped)
                 {
                     context.SkipRequest();
                     return;
                 }
 
-                else if (notification.IsRejected)
+                if (notification.IsRejected)
                 {
                     context.Reject(
                         error: notification.Error ?? Errors.InvalidRequest,
@@ -2369,13 +2369,13 @@ public static partial class OpenIddictServerHandlers
                     return;
                 }
 
-                else if (notification.IsRequestSkipped)
+                if (notification.IsRequestSkipped)
                 {
                     context.SkipRequest();
                     return;
                 }
 
-                else if (notification.IsRejected)
+                if (notification.IsRejected)
                 {
                     context.Reject(
                         error: notification.Error ?? Errors.InvalidRequest,
@@ -2433,13 +2433,13 @@ public static partial class OpenIddictServerHandlers
                     return;
                 }
 
-                else if (notification.IsRequestSkipped)
+                if (notification.IsRequestSkipped)
                 {
                     context.SkipRequest();
                     return;
                 }
 
-                else if (notification.IsRejected)
+                if (notification.IsRejected)
                 {
                     context.Reject(
                         error: notification.Error ?? Errors.InvalidRequest,
@@ -2493,13 +2493,13 @@ public static partial class OpenIddictServerHandlers
                     return;
                 }
 
-                else if (notification.IsRequestSkipped)
+                if (notification.IsRequestSkipped)
                 {
                     context.SkipRequest();
                     return;
                 }
 
-                else if (notification.IsRejected)
+                if (notification.IsRejected)
                 {
                     context.Reject(
                         error: notification.Error ?? Errors.InvalidRequest,
@@ -2539,13 +2539,13 @@ public static partial class OpenIddictServerHandlers
                     return;
                 }
 
-                else if (@event.IsRequestSkipped)
+                if (@event.IsRequestSkipped)
                 {
                     context.SkipRequest();
                     return;
                 }
 
-                else if (@event.IsRejected)
+                if (@event.IsRejected)
                 {
                     context.Reject(
                         error: @event.Error ?? Errors.InvalidGrant,
@@ -2592,7 +2592,7 @@ public static partial class OpenIddictServerHandlers
                     return;
                 }
 
-                else if (notification.IsRequestSkipped)
+                if (notification.IsRequestSkipped)
                 {
                     context.SkipRequest();
                     return;
@@ -3392,13 +3392,13 @@ public static partial class OpenIddictServerHandlers
                     return;
                 }
 
-                else if (notification.IsRequestSkipped)
+                if (notification.IsRequestSkipped)
                 {
                     context.SkipRequest();
                     return;
                 }
 
-                else if (notification.IsRejected)
+                if (notification.IsRejected)
                 {
                     context.Reject(
                         error: notification.Error ?? Errors.InvalidRequest,

src/OpenIddict.Server/OpenIddictServerHandlers.Device.cs

@@ -98,13 +98,13 @@ public static partial class OpenIddictServerHandlers
                     return;
                 }
 
-                else if (notification.IsRequestSkipped)
+                if (notification.IsRequestSkipped)
                 {
                     context.SkipRequest();
                     return;
                 }
 
-                else if (notification.IsRejected)
+                if (notification.IsRejected)
                 {
                     context.Reject(
                         error: notification.Error ?? Errors.InvalidRequest,
@@ -157,13 +157,13 @@ public static partial class OpenIddictServerHandlers
                     return;
                 }
 
-                else if (notification.IsRequestSkipped)
+                if (notification.IsRequestSkipped)
                 {
                     context.SkipRequest();
                     return;
                 }
 
-                else if (notification.IsRejected)
+                if (notification.IsRejected)
                 {
                     context.Reject(
                         error: notification.Error ?? Errors.InvalidRequest,
@@ -211,13 +211,13 @@ public static partial class OpenIddictServerHandlers
                     return;
                 }
 
-                else if (notification.IsRequestSkipped)
+                if (notification.IsRequestSkipped)
                 {
                     context.SkipRequest();
                     return;
                 }
 
-                else if (notification.IsRejected)
+                if (notification.IsRejected)
                 {
                     context.Reject(
                         error: notification.Error ?? Errors.InvalidRequest,
@@ -257,13 +257,13 @@ public static partial class OpenIddictServerHandlers
                     return;
                 }
 
-                else if (@event.IsRequestSkipped)
+                if (@event.IsRequestSkipped)
                 {
                     context.SkipRequest();
                     return;
                 }
 
-                else if (@event.IsRejected)
+                if (@event.IsRejected)
                 {
                     context.Reject(
                         error: @event.Error ?? Errors.InvalidGrant,
@@ -309,7 +309,7 @@ public static partial class OpenIddictServerHandlers
                     return;
                 }
 
-                else if (notification.IsRequestSkipped)
+                if (notification.IsRequestSkipped)
                 {
                     context.SkipRequest();
                     return;
@@ -544,13 +544,13 @@ public static partial class OpenIddictServerHandlers
                     return;
                 }
 
-                else if (notification.IsRequestSkipped)
+                if (notification.IsRequestSkipped)
                 {
                     context.SkipRequest();
                     return;
                 }
 
-                else if (notification.IsRejected)
+                if (notification.IsRejected)
                 {
                     context.Reject(
                         error: notification.Error ?? Errors.InvalidRequest,
@@ -778,13 +778,13 @@ public static partial class OpenIddictServerHandlers
                     return;
                 }
 
-                else if (notification.IsRequestSkipped)
+                if (notification.IsRequestSkipped)
                 {
                     context.SkipRequest();
                     return;
                 }
 
-                else if (notification.IsRejected)
+                if (notification.IsRejected)
                 {
                     context.Reject(
                         error: notification.Error ?? Errors.InvalidRequest,
@@ -841,13 +841,13 @@ public static partial class OpenIddictServerHandlers
                     return;
                 }
 
-                else if (notification.IsRequestSkipped)
+                if (notification.IsRequestSkipped)
                 {
                     context.SkipRequest();
                     return;
                 }
 
-                else if (notification.IsRejected)
+                if (notification.IsRejected)
                 {
                     context.Reject(
                         error: notification.Error ?? Errors.InvalidRequest,
@@ -895,13 +895,13 @@ public static partial class OpenIddictServerHandlers
                     return;
                 }
 
-                else if (notification.IsRequestSkipped)
+                if (notification.IsRequestSkipped)
                 {
                     context.SkipRequest();
                     return;
                 }
 
-                else if (notification.IsRejected)
+                if (notification.IsRejected)
                 {
                     context.Reject(
                         error: notification.Error ?? Errors.InvalidRequest,
@@ -934,13 +934,13 @@ public static partial class OpenIddictServerHandlers
                         return;
                     }
 
-                    else if (@event.IsRequestSkipped)
+                    if (@event.IsRequestSkipped)
                     {
                         context.SkipRequest();
                         return;
                     }
 
-                    else if (@event.IsRejected)
+                    if (@event.IsRejected)
                     {
                         context.Reject(
                             error: @event.Error ?? Errors.InvalidGrant,
@@ -989,7 +989,7 @@ public static partial class OpenIddictServerHandlers
                     return;
                 }
 
-                else if (notification.IsRequestSkipped)
+                if (notification.IsRequestSkipped)
                 {
                     context.SkipRequest();
                     return;
@@ -1037,13 +1037,13 @@ public static partial class OpenIddictServerHandlers
                     return;
                 }
 
-                else if (notification.IsRequestSkipped)
+                if (notification.IsRequestSkipped)
                 {
                     context.SkipRequest();
                     return;
                 }
 
-                else if (notification.IsRejected)
+                if (notification.IsRejected)
                 {
                     context.Reject(
                         error: notification.Error ?? Errors.InvalidRequest,

src/OpenIddict.Server/OpenIddictServerHandlers.Discovery.cs

@@ -99,13 +99,13 @@ public static partial class OpenIddictServerHandlers
                     return;
                 }
 
-                else if (notification.IsRequestSkipped)
+                if (notification.IsRequestSkipped)
                 {
                     context.SkipRequest();
                     return;
                 }
 
-                else if (notification.IsRejected)
+                if (notification.IsRejected)
                 {
                     context.Reject(
                         error: notification.Error ?? Errors.InvalidRequest,
@@ -158,13 +158,13 @@ public static partial class OpenIddictServerHandlers
                     return;
                 }
 
-                else if (notification.IsRequestSkipped)
+                if (notification.IsRequestSkipped)
                 {
                     context.SkipRequest();
                     return;
                 }
 
-                else if (notification.IsRejected)
+                if (notification.IsRejected)
                 {
                     context.Reject(
                         error: notification.Error ?? Errors.InvalidRequest,
@@ -212,13 +212,13 @@ public static partial class OpenIddictServerHandlers
                     return;
                 }
 
-                else if (notification.IsRequestSkipped)
+                if (notification.IsRequestSkipped)
                 {
                     context.SkipRequest();
                     return;
                 }
 
-                else if (notification.IsRejected)
+                if (notification.IsRejected)
                 {
                     context.Reject(
                         error: notification.Error ?? Errors.InvalidRequest,
@@ -339,7 +339,7 @@ public static partial class OpenIddictServerHandlers
                     return;
                 }
 
-                else if (notification.IsRequestSkipped)
+                if (notification.IsRequestSkipped)
                 {
                     context.SkipRequest();
                     return;
@@ -902,13 +902,13 @@ public static partial class OpenIddictServerHandlers
                     return;
                 }
 
-                else if (notification.IsRequestSkipped)
+                if (notification.IsRequestSkipped)
                 {
                     context.SkipRequest();
                     return;
                 }
 
-                else if (notification.IsRejected)
+                if (notification.IsRejected)
                 {
                     context.Reject(
                         error: notification.Error ?? Errors.InvalidRequest,
@@ -961,13 +961,13 @@ public static partial class OpenIddictServerHandlers
                     return;
                 }
 
-                else if (notification.IsRequestSkipped)
+                if (notification.IsRequestSkipped)
                 {
                     context.SkipRequest();
                     return;
                 }
 
-                else if (notification.IsRejected)
+                if (notification.IsRejected)
                 {
                     context.Reject(
                         error: notification.Error ?? Errors.InvalidRequest,
@@ -1015,13 +1015,13 @@ public static partial class OpenIddictServerHandlers
                     return;
                 }
 
-                else if (notification.IsRequestSkipped)
+                if (notification.IsRequestSkipped)
                 {
                     context.SkipRequest();
                     return;
                 }
 
-                else if (notification.IsRejected)
+                if (notification.IsRejected)
                 {
                     context.Reject(
                         error: notification.Error ?? Errors.InvalidRequest,
@@ -1166,7 +1166,7 @@ public static partial class OpenIddictServerHandlers
                     return;
                 }
 
-                else if (notification.IsRequestSkipped)
+                if (notification.IsRequestSkipped)
                 {
                     context.SkipRequest();
                     return;
@@ -1257,7 +1257,7 @@ public static partial class OpenIddictServerHandlers
                     if (credentials.Key.IsSupportedAlgorithm(SecurityAlgorithms.EcdsaSha256) ||
                         credentials.Key.IsSupportedAlgorithm(SecurityAlgorithms.EcdsaSha384) ||
                         credentials.Key.IsSupportedAlgorithm(SecurityAlgorithms.EcdsaSha512))
-                    {;
+                    {
                         if (!TryGetECParameters(credentials.Key, out var parameters))
                         {
                             context.Logger.LogWarning(6074, SR.GetResourceString(SR.ID6074), credentials.Key.GetType().Name);

src/OpenIddict.Server/OpenIddictServerHandlers.Exchange.cs

@@ -110,13 +110,13 @@ public static partial class OpenIddictServerHandlers
                     return;
                 }
 
-                else if (notification.IsRequestSkipped)
+                if (notification.IsRequestSkipped)
                 {
                     context.SkipRequest();
                     return;
                 }
 
-                else if (notification.IsRejected)
+                if (notification.IsRejected)
                 {
                     context.Reject(
                         error: notification.Error ?? Errors.InvalidRequest,
@@ -173,13 +173,13 @@ public static partial class OpenIddictServerHandlers
                     return;
                 }
 
-                else if (notification.IsRequestSkipped)
+                if (notification.IsRequestSkipped)
                 {
                     context.SkipRequest();
                     return;
                 }
 
-                else if (notification.IsRejected)
+                if (notification.IsRejected)
                 {
                     context.Reject(
                         error: notification.Error ?? Errors.InvalidRequest,
@@ -227,13 +227,13 @@ public static partial class OpenIddictServerHandlers
                     return;
                 }
 
-                else if (notification.IsRequestSkipped)
+                if (notification.IsRequestSkipped)
                 {
                     context.SkipRequest();
                     return;
                 }
 
-                else if (notification.IsRejected)
+                if (notification.IsRejected)
                 {
                     context.Reject(
                         error: notification.Error ?? Errors.InvalidGrant,
@@ -266,13 +266,13 @@ public static partial class OpenIddictServerHandlers
                         return;
                     }
 
-                    else if (@event.IsRequestSkipped)
+                    if (@event.IsRequestSkipped)
                     {
                         context.SkipRequest();
                         return;
                     }
 
-                    else if (@event.IsRejected)
+                    if (@event.IsRejected)
                     {
                         context.Reject(
                             error: @event.Error ?? Errors.InvalidRequest,
@@ -321,7 +321,7 @@ public static partial class OpenIddictServerHandlers
                     return;
                 }
 
-                else if (notification.IsRequestSkipped)
+                if (notification.IsRequestSkipped)
                 {
                     context.SkipRequest();
                     return;
@@ -1226,13 +1226,13 @@ public static partial class OpenIddictServerHandlers
                     return;
                 }
 
-                else if (notification.IsRequestSkipped)
+                if (notification.IsRequestSkipped)
                 {
                     context.SkipRequest();
                     return;
                 }
 
-                else if (notification.IsRejected)
+                if (notification.IsRejected)
                 {
                     context.Reject(
                         error: notification.Error ?? Errors.InvalidRequest,
@@ -2099,11 +2099,7 @@ public static partial class OpenIddictServerHandlers
                     return ValueTask.CompletedTask;
                 }
 
-                // When an explicit scope parameter has been included in the token request,
-                // the authorization server MUST ensure that it doesn't contain scopes
-                // that were not granted during the initial authorization/token request.
-                // See https://tools.ietf.org/html/rfc6749#section-6 for more information.
-                else if (!scopes.IsSupersetOf(context.Request.GetScopes()))
+                if (!scopes.IsSupersetOf(context.Request.GetScopes()))
                 {
                     context.Logger.LogInformation(6095, SR.GetResourceString(SR.ID6095), Parameters.Scope);
 
@@ -2172,7 +2168,7 @@ public static partial class OpenIddictServerHandlers
                     // reused as-is and that a new ad-hoc authorization, separate from the one attached
                     // to the subject token will be created and attached to the issued token by OpenIddict.
                     GrantTypes.TokenExchange => notification.SubjectTokenPrincipal
-                        ?.Clone(claim => !claim.Type.StartsWith(Claims.Prefixes.Private)),
+                        ?.Clone(claim => !claim.Type.StartsWith(Claims.Prefixes.Private, StringComparison.Ordinal)),
 
                     _ => null
                 };

src/OpenIddict.Server/OpenIddictServerHandlers.Introspection.cs

@@ -91,13 +91,13 @@ public static partial class OpenIddictServerHandlers
                     return;
                 }
 
-                else if (notification.IsRequestSkipped)
+                if (notification.IsRequestSkipped)
                 {
                     context.SkipRequest();
                     return;
                 }
 
-                else if (notification.IsRejected)
+                if (notification.IsRejected)
                 {
                     context.Reject(
                         error: notification.Error ?? Errors.InvalidRequest,
@@ -154,13 +154,13 @@ public static partial class OpenIddictServerHandlers
                     return;
                 }
 
-                else if (notification.IsRequestSkipped)
+                if (notification.IsRequestSkipped)
                 {
                     context.SkipRequest();
                     return;
                 }
 
-                else if (notification.IsRejected)
+                if (notification.IsRejected)
                 {
                     context.Reject(
                         error: notification.Error ?? Errors.InvalidRequest,
@@ -208,13 +208,13 @@ public static partial class OpenIddictServerHandlers
                     return;
                 }
 
-                else if (notification.IsRequestSkipped)
+                if (notification.IsRequestSkipped)
                 {
                     context.SkipRequest();
                     return;
                 }
 
-                else if (notification.IsRejected)
+                if (notification.IsRejected)
                 {
                     context.Reject(
                         error: notification.Error ?? Errors.InvalidRequest,
@@ -229,7 +229,7 @@ public static partial class OpenIddictServerHandlers
                     [Claims.Issuer] = notification.Issuer?.AbsoluteUri,
                     [Claims.Username] = notification.Username,
                     [Claims.Subject] = notification.Subject,
-                    [Claims.Scope] = string.Join(" ", notification.Scopes),
+                    [Claims.Scope] = string.Join(Separators.Space[0], notification.Scopes),
                     [Claims.JwtId] = notification.TokenId,
                     [Claims.TokenType] = notification.TokenType,
                     [Claims.TokenUsage] = notification.TokenUsage,
@@ -313,7 +313,7 @@ public static partial class OpenIddictServerHandlers
                     return;
                 }
 
-                else if (notification.IsRequestSkipped)
+                if (notification.IsRequestSkipped)
                 {
                     context.SkipRequest();
                     return;
@@ -474,13 +474,13 @@ public static partial class OpenIddictServerHandlers
                     return;
                 }
 
-                else if (notification.IsRequestSkipped)
+                if (notification.IsRequestSkipped)
                 {
                     context.SkipRequest();
                     return;
                 }
 
-                else if (notification.IsRejected)
+                if (notification.IsRejected)
                 {
                     context.Reject(
                         error: notification.Error ?? Errors.InvalidRequest,
@@ -830,7 +830,7 @@ public static partial class OpenIddictServerHandlers
                 context.Username = context.GenericTokenPrincipal.Identity.Name;
                 context.Scopes.UnionWith(context.GenericTokenPrincipal.GetScopes());
 
-                foreach (var group in context.GenericTokenPrincipal.Claims.GroupBy(claim => claim.Type))
+                foreach (var group in context.GenericTokenPrincipal.Claims.GroupBy(claim => claim.Type, StringComparer.Ordinal))
                 {
                     // Exclude standard claims, that are already handled via strongly-typed properties.
                     // Make sure to always update this list when adding new built-in claim properties.

src/OpenIddict.Server/OpenIddictServerHandlers.Protection.cs

@@ -587,7 +587,7 @@ public static partial class OpenIddictServerHandlers
                 // retrieved as a Dictionary<string, string[]> and converted to ImmutableDictionary<string, ImmutableArray<string>.
                 if (token.TryGetPayloadValue(Claims.Private.ClaimDestinationsMap, out Dictionary<string, string[]> destinations))
                 {
-                    var builder = ImmutableDictionary.CreateBuilder<string, ImmutableArray<string>>();
+                    var builder = ImmutableDictionary.CreateBuilder<string, ImmutableArray<string>>(StringComparer.Ordinal);
 
                     foreach (var destination in destinations)
                     {
@@ -640,7 +640,7 @@ public static partial class OpenIddictServerHandlers
                 var scopes = context.Principal.GetClaims(Claims.Scope);
                 if (scopes.Length is > 1)
                 {
-                    context.Principal.SetClaim(Claims.Scope, string.Join(" ", scopes));
+                    context.Principal.SetClaim(Claims.Scope, string.Join(Separators.Space[0], scopes));
                 }
 
                 return ValueTask.CompletedTask;
@@ -1700,7 +1700,7 @@ public static partial class OpenIddictServerHandlers
                     var scopes = context.Principal.GetScopes();
                     if (scopes.Any())
                     {
-                        claims.Add(Claims.Scope, string.Join(" ", scopes));
+                        claims.Add(Claims.Scope, string.Join(Separators.Space[0], scopes));
                     }
 
                     claims.Add(Claims.JwtId, Guid.NewGuid().ToString());

src/OpenIddict.Server/OpenIddictServerHandlers.Revocation.cs

@@ -83,13 +83,13 @@ public static partial class OpenIddictServerHandlers
                     return;
                 }
 
-                else if (notification.IsRequestSkipped)
+                if (notification.IsRequestSkipped)
                 {
                     context.SkipRequest();
                     return;
                 }
 
-                else if (notification.IsRejected)
+                if (notification.IsRejected)
                 {
                     context.Reject(
                         error: notification.Error ?? Errors.InvalidRequest,
@@ -146,13 +146,13 @@ public static partial class OpenIddictServerHandlers
                     return;
                 }
 
-                else if (notification.IsRequestSkipped)
+                if (notification.IsRequestSkipped)
                 {
                     context.SkipRequest();
                     return;
                 }
 
-                else if (notification.IsRejected)
+                if (notification.IsRejected)
                 {
                     context.Reject(
                         error: notification.Error ?? Errors.InvalidRequest,
@@ -200,13 +200,13 @@ public static partial class OpenIddictServerHandlers
                     return;
                 }
 
-                else if (notification.IsRequestSkipped)
+                if (notification.IsRequestSkipped)
                 {
                     context.SkipRequest();
                     return;
                 }
 
-                else if (notification.IsRejected)
+                if (notification.IsRejected)
                 {
                     context.Reject(
                         error: notification.Error ?? Errors.InvalidRequest,
@@ -254,7 +254,7 @@ public static partial class OpenIddictServerHandlers
                     return;
                 }
 
-                else if (notification.IsRequestSkipped)
+                if (notification.IsRequestSkipped)
                 {
                     context.SkipRequest();
                     return;
@@ -415,13 +415,13 @@ public static partial class OpenIddictServerHandlers
                     return;
                 }
 
-                else if (notification.IsRequestSkipped)
+                if (notification.IsRequestSkipped)
                 {
                     context.SkipRequest();
                     return;
                 }
 
-                else if (notification.IsRejected)
+                if (notification.IsRejected)
                 {
                     context.Reject(
                         error: notification.Error ?? Errors.InvalidRequest,

src/OpenIddict.Server/OpenIddictServerHandlers.Session.cs

@@ -90,13 +90,13 @@ public static partial class OpenIddictServerHandlers
                     return;
                 }
 
-                else if (notification.IsRequestSkipped)
+                if (notification.IsRequestSkipped)
                 {
                     context.SkipRequest();
                     return;
                 }
 
-                else if (notification.IsRejected)
+                if (notification.IsRejected)
                 {
                     context.Reject(
                         error: notification.Error ?? Errors.InvalidRequest,
@@ -153,13 +153,13 @@ public static partial class OpenIddictServerHandlers
                     return;
                 }
 
-                else if (notification.IsRequestSkipped)
+                if (notification.IsRequestSkipped)
                 {
                     context.SkipRequest();
                     return;
                 }
 
-                else if (notification.IsRejected)
+                if (notification.IsRejected)
                 {
                     context.Reject(
                         error: notification.Error ?? Errors.InvalidRequest,
@@ -207,13 +207,13 @@ public static partial class OpenIddictServerHandlers
                     return;
                 }
 
-                else if (notification.IsRequestSkipped)
+                if (notification.IsRequestSkipped)
                 {
                     context.SkipRequest();
                     return;
                 }
 
-                else if (notification.IsRejected)
+                if (notification.IsRejected)
                 {
                     context.Reject(
                         error: notification.Error ?? Errors.InvalidRequest,
@@ -245,13 +245,13 @@ public static partial class OpenIddictServerHandlers
                         return;
                     }
 
-                    else if (@event.IsRequestSkipped)
+                    if (@event.IsRequestSkipped)
                     {
                         context.SkipRequest();
                         return;
                     }
 
-                    else if (@event.IsRejected)
+                    if (@event.IsRejected)
                     {
                         context.Reject(
                             error: @event.Error ?? Errors.InvalidRequest,
@@ -286,13 +286,13 @@ public static partial class OpenIddictServerHandlers
                         return;
                     }
 
-                    else if (@event.IsRequestSkipped)
+                    if (@event.IsRequestSkipped)
                     {
                         context.SkipRequest();
                         return;
                     }
 
-                    else if (@event.IsRejected)
+                    if (@event.IsRejected)
                     {
                         context.Reject(
                             error: notification.Error ?? Errors.InvalidRequest,
@@ -341,7 +341,7 @@ public static partial class OpenIddictServerHandlers
                     return;
                 }
 
-                else if (notification.IsRequestSkipped)
+                if (notification.IsRequestSkipped)
                 {
                     context.SkipRequest();
                     return;
@@ -488,13 +488,13 @@ public static partial class OpenIddictServerHandlers
                     return;
                 }
 
-                else if (notification.IsRequestSkipped)
+                if (notification.IsRequestSkipped)
                 {
                     context.SkipRequest();
                     return;
                 }
 
-                else if (notification.IsRejected)
+                if (notification.IsRejected)
                 {
                     context.Reject(
                         error: notification.Error ?? Errors.InvalidRequest,

src/OpenIddict.Server/OpenIddictServerHandlers.Userinfo.cs

@@ -76,13 +76,13 @@ public static partial class OpenIddictServerHandlers
                     return;
                 }
 
-                else if (notification.IsRequestSkipped)
+                if (notification.IsRequestSkipped)
                 {
                     context.SkipRequest();
                     return;
                 }
 
-                else if (notification.IsRejected)
+                if (notification.IsRejected)
                 {
                     context.Reject(
                         error: notification.Error ?? Errors.InvalidRequest,
@@ -139,13 +139,13 @@ public static partial class OpenIddictServerHandlers
                     return;
                 }
 
-                else if (notification.IsRequestSkipped)
+                if (notification.IsRequestSkipped)
                 {
                     context.SkipRequest();
                     return;
                 }
 
-                else if (notification.IsRejected)
+                if (notification.IsRejected)
                 {
                     context.Reject(
                         error: notification.Error ?? Errors.InvalidRequest,
@@ -193,13 +193,13 @@ public static partial class OpenIddictServerHandlers
                     return;
                 }
 
-                else if (notification.IsRequestSkipped)
+                if (notification.IsRequestSkipped)
                 {
                     context.SkipRequest();
                     return;
                 }
 
-                else if (notification.IsRejected)
+                if (notification.IsRejected)
                 {
                     context.Reject(
                         error: notification.Error ?? Errors.InvalidRequest,
@@ -282,7 +282,7 @@ public static partial class OpenIddictServerHandlers
                     return;
                 }
 
-                else if (notification.IsRequestSkipped)
+                if (notification.IsRequestSkipped)
                 {
                     context.SkipRequest();
                     return;
@@ -366,13 +366,13 @@ public static partial class OpenIddictServerHandlers
                     return;
                 }
 
-                else if (notification.IsRequestSkipped)
+                if (notification.IsRequestSkipped)
                 {
                     context.SkipRequest();
                     return;
                 }
 
-                else if (notification.IsRejected)
+                if (notification.IsRejected)
                 {
                     context.Reject(
                         error: notification.Error ?? Errors.InvalidRequest,

src/OpenIddict.Server/OpenIddictServerHandlers.cs

@@ -662,13 +662,13 @@ public static partial class OpenIddictServerHandlers
                 return;
             }
 
-            else if (notification.IsRequestSkipped)
+            if (notification.IsRequestSkipped)
             {
                 context.SkipRequest();
                 return;
             }
 
-            else if (notification.IsRejected)
+            if (notification.IsRejected)
             {
                 if (context.RejectClientAssertion)
                 {
@@ -710,8 +710,8 @@ public static partial class OpenIddictServerHandlers
             Debug.Assert(context.ClientAssertionPrincipal is { Identity: ClaimsIdentity }, SR.GetResourceString(SR.ID4006));
 
             foreach (var group in context.ClientAssertionPrincipal.Claims
-                .GroupBy(static claim => claim.Type)
-                .ToDictionary(static group => group.Key, group => group.ToList())
+                .GroupBy(static claim => claim.Type, StringComparer.Ordinal)
+                .ToDictionary(static group => group.Key, group => group.ToList(), StringComparer.Ordinal)
                 .Where(static group => !ValidateClaimGroup(group.Key, group.Value)))
             {
                 context.Reject(
@@ -1545,13 +1545,13 @@ public static partial class OpenIddictServerHandlers
                 return;
             }
 
-            else if (notification.IsRequestSkipped)
+            if (notification.IsRequestSkipped)
             {
                 context.SkipRequest();
                 return;
             }
 
-            else if (notification.IsRejected)
+            if (notification.IsRejected)
             {
                 if (context.RejectRequestToken)
                 {
@@ -1667,13 +1667,13 @@ public static partial class OpenIddictServerHandlers
                 return;
             }
 
-            else if (notification.IsRequestSkipped)
+            if (notification.IsRequestSkipped)
             {
                 context.SkipRequest();
                 return;
             }
 
-            else if (notification.IsRejected)
+            if (notification.IsRejected)
             {
                 if (context.RejectAccessToken)
                 {
@@ -1746,13 +1746,13 @@ public static partial class OpenIddictServerHandlers
                 return;
             }
 
-            else if (notification.IsRequestSkipped)
+            if (notification.IsRequestSkipped)
             {
                 context.SkipRequest();
                 return;
             }
 
-            else if (notification.IsRejected)
+            if (notification.IsRejected)
             {
                 if (context.RejectAuthorizationCode)
                 {
@@ -1825,13 +1825,13 @@ public static partial class OpenIddictServerHandlers
                 return;
             }
 
-            else if (notification.IsRequestSkipped)
+            if (notification.IsRequestSkipped)
             {
                 context.SkipRequest();
                 return;
             }
 
-            else if (notification.IsRejected)
+            if (notification.IsRejected)
             {
                 if (context.RejectDeviceCode)
                 {
@@ -1921,13 +1921,13 @@ public static partial class OpenIddictServerHandlers
                 return;
             }
 
-            else if (notification.IsRequestSkipped)
+            if (notification.IsRequestSkipped)
             {
                 context.SkipRequest();
                 return;
             }
 
-            else if (notification.IsRejected)
+            if (notification.IsRejected)
             {
                 if (context.RejectGenericToken)
                 {
@@ -2007,13 +2007,13 @@ public static partial class OpenIddictServerHandlers
                 return;
             }
 
-            else if (notification.IsRequestSkipped)
+            if (notification.IsRequestSkipped)
             {
                 context.SkipRequest();
                 return;
             }
 
-            else if (notification.IsRejected)
+            if (notification.IsRejected)
             {
                 if (context.RejectIdentityToken)
                 {
@@ -2086,13 +2086,13 @@ public static partial class OpenIddictServerHandlers
                 return;
             }
 
-            else if (notification.IsRequestSkipped)
+            if (notification.IsRequestSkipped)
             {
                 context.SkipRequest();
                 return;
             }
 
-            else if (notification.IsRejected)
+            if (notification.IsRejected)
             {
                 if (context.RejectRefreshToken)
                 {
@@ -2192,13 +2192,13 @@ public static partial class OpenIddictServerHandlers
                 return;
             }
 
-            else if (notification.IsRequestSkipped)
+            if (notification.IsRequestSkipped)
             {
                 context.SkipRequest();
                 return;
             }
 
-            else if (notification.IsRejected)
+            if (notification.IsRejected)
             {
                 if (context.RejectSubjectToken)
                 {
@@ -2298,13 +2298,13 @@ public static partial class OpenIddictServerHandlers
                 return;
             }
 
-            else if (notification.IsRequestSkipped)
+            if (notification.IsRequestSkipped)
             {
                 context.SkipRequest();
                 return;
             }
 
-            else if (notification.IsRejected)
+            if (notification.IsRejected)
             {
                 if (context.RejectActorToken)
                 {
@@ -2377,13 +2377,13 @@ public static partial class OpenIddictServerHandlers
                 return;
             }
 
-            else if (notification.IsRequestSkipped)
+            if (notification.IsRequestSkipped)
             {
                 context.SkipRequest();
                 return;
             }
 
-            else if (notification.IsRejected)
+            if (notification.IsRejected)
             {
                 if (context.RejectUserCode)
                 {
@@ -2840,8 +2840,8 @@ public static partial class OpenIddictServerHandlers
             }
 
             foreach (var group in context.Principal.Claims
-                .GroupBy(static claim => claim.Type)
-                .ToDictionary(static group => group.Key, static group => group.ToList())
+                .GroupBy(static claim => claim.Type, StringComparer.Ordinal)
+                .ToDictionary(static group => group.Key, static group => group.ToList(), StringComparer.Ordinal)
                 .Where(static group => !ValidateClaimGroup(group.Key, group.Value)))
             {
                 throw new InvalidOperationException(SR.FormatID0424(group.Key));
@@ -3089,11 +3089,11 @@ public static partial class OpenIddictServerHandlers
 
             // Restore the internal claims resolved from the token.
             foreach (var claims in principal.Claims
-                .Where(claim => claim.Type.StartsWith(Claims.Prefixes.Private, StringComparison.OrdinalIgnoreCase))
-                .GroupBy(claim => claim.Type))
+                .Where(claim => claim.Type.StartsWith(Claims.Prefixes.Private, StringComparison.Ordinal))
+                .GroupBy(claim => claim.Type, StringComparer.Ordinal))
             {
                 // If the specified principal already contains one claim of the iterated type, ignore them.
-                if (context.Principal.Claims.Any(claim => claim.Type == claims.Key))
+                if (context.Principal.Claims.Any(claim => string.Equals(claim.Type, claims.Key, StringComparison.Ordinal)))
                 {
                     continue;
                 }
@@ -3652,7 +3652,7 @@ public static partial class OpenIddictServerHandlers
                 context.Request.IsRefreshTokenGrantType() && !string.IsNullOrEmpty(context.Request.Scope))
             {
                 var scopes = context.Request.GetScopes();
-                principal.SetScopes(scopes.Intersect(context.Principal.GetScopes()));
+                principal.SetScopes(scopes.Intersect(context.Principal.GetScopes(), StringComparer.Ordinal));
 
                 context.Logger.LogDebug(6010, SR.GetResourceString(SR.ID6010), scopes);
             }
@@ -4807,13 +4807,13 @@ public static partial class OpenIddictServerHandlers
                 return;
             }
 
-            else if (notification.IsRequestSkipped)
+            if (notification.IsRequestSkipped)
             {
                 context.SkipRequest();
                 return;
             }
 
-            else if (notification.IsRejected)
+            if (notification.IsRejected)
             {
                 context.Reject(
                     error: notification.Error ?? Errors.InvalidRequest,
@@ -4871,13 +4871,13 @@ public static partial class OpenIddictServerHandlers
                 return;
             }
 
-            else if (notification.IsRequestSkipped)
+            if (notification.IsRequestSkipped)
             {
                 context.SkipRequest();
                 return;
             }
 
-            else if (notification.IsRejected)
+            if (notification.IsRejected)
             {
                 context.Reject(
                     error: notification.Error ?? Errors.InvalidRequest,
@@ -4949,13 +4949,13 @@ public static partial class OpenIddictServerHandlers
                 return;
             }
 
-            else if (notification.IsRequestSkipped)
+            if (notification.IsRequestSkipped)
             {
                 context.SkipRequest();
                 return;
             }
 
-            else if (notification.IsRejected)
+            if (notification.IsRejected)
             {
                 context.Reject(
                     error: notification.Error ?? Errors.InvalidRequest,
@@ -5025,13 +5025,13 @@ public static partial class OpenIddictServerHandlers
                 return;
             }
 
-            else if (notification.IsRequestSkipped)
+            if (notification.IsRequestSkipped)
             {
                 context.SkipRequest();
                 return;
             }
 
-            else if (notification.IsRejected)
+            if (notification.IsRejected)
             {
                 context.Reject(
                     error: notification.Error ?? Errors.InvalidRequest,
@@ -5089,13 +5089,13 @@ public static partial class OpenIddictServerHandlers
                 return;
             }
 
-            else if (notification.IsRequestSkipped)
+            if (notification.IsRequestSkipped)
             {
                 context.SkipRequest();
                 return;
             }
 
-            else if (notification.IsRejected)
+            if (notification.IsRejected)
             {
                 context.Reject(
                     error: notification.Error ?? Errors.InvalidRequest,
@@ -5155,13 +5155,13 @@ public static partial class OpenIddictServerHandlers
                 return;
             }
 
-            else if (notification.IsRequestSkipped)
+            if (notification.IsRequestSkipped)
             {
                 context.SkipRequest();
                 return;
             }
 
-            else if (notification.IsRejected)
+            if (notification.IsRejected)
             {
                 context.Reject(
                     error: notification.Error ?? Errors.InvalidRequest,
@@ -5436,13 +5436,13 @@ public static partial class OpenIddictServerHandlers
                 return;
             }
 
-            else if (notification.IsRequestSkipped)
+            if (notification.IsRequestSkipped)
             {
                 context.SkipRequest();
                 return;
             }
 
-            else if (notification.IsRejected)
+            if (notification.IsRejected)
             {
                 context.Reject(
                     error: notification.Error ?? Errors.InvalidRequest,
@@ -5501,13 +5501,13 @@ public static partial class OpenIddictServerHandlers
                 return;
             }
 
-            else if (notification.IsRequestSkipped)
+            if (notification.IsRequestSkipped)
             {
                 context.SkipRequest();
                 return;
             }
 
-            else if (notification.IsRejected)
+            if (notification.IsRejected)
             {
                 context.Reject(
                     error: notification.Error ?? Errors.InvalidRequest,
@@ -5622,7 +5622,7 @@ public static partial class OpenIddictServerHandlers
                          context.Request.IsAuthorizationCodeGrantType()) ||
                         !scopes.SetEquals(context.Request.GetScopes()))
                     {
-                        context.Response.Scope = string.Join(" ", scopes);
+                        context.Response.Scope = string.Join(Separators.Space[0], scopes);
                     }
                 }
             }

src/OpenIddict.Validation.AspNetCore/OpenIddictValidationAspNetCoreHandler.cs

@@ -74,12 +74,12 @@ public sealed class OpenIddictValidationAspNetCoreHandler : AuthenticationHandle
             return true;
         }
 
-        else if (context.IsRequestSkipped)
+        if (context.IsRequestSkipped)
         {
             return false;
         }
 
-        else if (context.IsRejected)
+        if (context.IsRejected)
         {
             var notification = new ProcessErrorContext(transaction)
             {
@@ -96,7 +96,7 @@ public sealed class OpenIddictValidationAspNetCoreHandler : AuthenticationHandle
                 return true;
             }
 
-            else if (notification.IsRequestSkipped)
+            if (notification.IsRequestSkipped)
             {
                 return false;
             }
@@ -131,7 +131,7 @@ public sealed class OpenIddictValidationAspNetCoreHandler : AuthenticationHandle
             return AuthenticateResult.NoResult();
         }
 
-        else if (context.IsRejected)
+        if (context.IsRejected)
         {
             // Note: the missing_token error is special-cased to indicate to ASP.NET Core
             // that no authentication result could be produced due to the lack of token.
@@ -226,7 +226,7 @@ public sealed class OpenIddictValidationAspNetCoreHandler : AuthenticationHandle
             return;
         }
 
-        else if (context.IsRejected)
+        if (context.IsRejected)
         {
             var notification = new ProcessErrorContext(transaction)
             {

src/OpenIddict.Validation.AspNetCore/OpenIddictValidationAspNetCoreHandlers.cs

@@ -23,7 +23,7 @@ using Properties = OpenIddict.Validation.AspNetCore.OpenIddictValidationAspNetCo
 namespace OpenIddict.Validation.AspNetCore;
 
 [EditorBrowsable(EditorBrowsableState.Never)]
-public static partial class OpenIddictValidationAspNetCoreHandlers
+public static class OpenIddictValidationAspNetCoreHandlers
 {
     public static ImmutableArray<OpenIddictValidationHandlerDescriptor> DefaultHandlers { get; } =
     [
@@ -601,7 +601,7 @@ public static partial class OpenIddictValidationAspNetCoreHandlers
                 builder.Append(parameter.Key);
                 builder.Append('=');
                 builder.Append('"');
-                builder.Append(parameter.Value.Replace("\"", "\\\""));
+                builder.Append(parameter.Value.Replace("\"", "\\\"", StringComparison.Ordinal));
                 builder.Append('"');
                 builder.Append(',');
             }

src/OpenIddict.Validation.Owin/OpenIddictValidationOwinHandler.cs

@@ -86,12 +86,12 @@ public sealed class OpenIddictValidationOwinHandler : AuthenticationHandler<Auth
             return true;
         }
 
-        else if (context.IsRequestSkipped)
+        if (context.IsRequestSkipped)
         {
             return false;
         }
 
-        else if (context.IsRejected)
+        if (context.IsRejected)
         {
             var notification = new ProcessErrorContext(transaction)
             {
@@ -108,7 +108,7 @@ public sealed class OpenIddictValidationOwinHandler : AuthenticationHandler<Auth
                 return true;
             }
 
-            else if (notification.IsRequestSkipped)
+            if (notification.IsRequestSkipped)
             {
                 return false;
             }
@@ -143,7 +143,7 @@ public sealed class OpenIddictValidationOwinHandler : AuthenticationHandler<Auth
             return null;
         }
 
-        else if (context.IsRejected)
+        if (context.IsRejected)
         {
             // Note: the missing_token error is special-cased to indicate to Katana
             // that no authentication result could be produced due to the lack of token.
@@ -234,7 +234,7 @@ public sealed class OpenIddictValidationOwinHandler : AuthenticationHandler<Auth
                 return;
             }
 
-            else if (context.IsRejected)
+            if (context.IsRejected)
             {
                 var notification = new ProcessErrorContext(transaction)
                 {

src/OpenIddict.Validation.Owin/OpenIddictValidationOwinHandlers.cs

@@ -20,7 +20,7 @@ using Properties = OpenIddict.Validation.Owin.OpenIddictValidationOwinConstants.
 namespace OpenIddict.Validation.Owin;
 
 [EditorBrowsable(EditorBrowsableState.Never)]
-public static partial class OpenIddictValidationOwinHandlers
+public static class OpenIddictValidationOwinHandlers
 {
     public static ImmutableArray<OpenIddictValidationHandlerDescriptor> DefaultHandlers { get; } =
     [
@@ -752,7 +752,7 @@ public static partial class OpenIddictValidationOwinHandlers
                 builder.Append(parameter.Key);
                 builder.Append('=');
                 builder.Append('"');
-                builder.Append(parameter.Value.Replace("\"", "\\\""));
+                builder.Append(parameter.Value.Replace("\"", "\\\"", StringComparison.Ordinal));
                 builder.Append('"');
                 builder.Append(',');
             }

src/OpenIddict.Validation.SystemNetHttp/OpenIddictValidationSystemNetHttpHandlers.cs

@@ -370,7 +370,7 @@ public static partial class OpenIddictValidationSystemNetHttpHandlers
             return ValueTask.CompletedTask;
 
             static string? EscapeDataString(string? value)
-                => value is not null ? Uri.EscapeDataString(value).Replace("%20", "+") : null;
+                => value is not null ? Uri.EscapeDataString(value).Replace("%20", "+", StringComparison.Ordinal) : null;
         }
     }
 
@@ -413,7 +413,8 @@ public static partial class OpenIddictValidationSystemNetHttpHandlers
                 request.RequestUri = OpenIddictHelpers.AddQueryStringParameters(request.RequestUri,
                     context.Transaction.Request.GetParameters().ToDictionary(
                         static parameter => parameter.Key,
-                        static parameter => (StringValues) parameter.Value));
+                        static parameter => (StringValues) parameter.Value,
+                        StringComparer.Ordinal));
             }
 
             // For POST requests, attach the request parameters to the request form by default.
@@ -605,7 +606,7 @@ public static partial class OpenIddictValidationSystemNetHttpHandlers
                     continue;
                 }
 
-                else if (string.Equals(encoding, ContentEncodings.Gzip, StringComparison.OrdinalIgnoreCase))
+                if (string.Equals(encoding, ContentEncodings.Gzip, StringComparison.OrdinalIgnoreCase))
                 {
                     stream ??= await response.Content.ReadAsStreamAsync().WaitAsync(context.CancellationToken);
                     stream = new GZipStream(stream, CompressionMode.Decompress);

src/OpenIddict.Validation/OpenIddictValidationHandlers.Protection.cs

@@ -410,7 +410,7 @@ public static partial class OpenIddictValidationHandlers
                 var scopes = context.Principal.GetClaims(Claims.Scope);
                 if (scopes.Length is > 1)
                 {
-                    context.Principal.SetClaim(Claims.Scope, string.Join(" ", scopes));
+                    context.Principal.SetClaim(Claims.Scope, string.Join(Separators.Space[0], scopes));
                 }
 
                 return ValueTask.CompletedTask;

src/OpenIddict.Validation/OpenIddictValidationHandlers.cs

@@ -602,13 +602,13 @@ public static partial class OpenIddictValidationHandlers
                 return;
             }
 
-            else if (notification.IsRequestSkipped)
+            if (notification.IsRequestSkipped)
             {
                 context.SkipRequest();
                 return;
             }
 
-            else if (notification.IsRejected)
+            if (notification.IsRejected)
             {
                 context.Reject(
                     error: notification.Error ?? Errors.InvalidRequest,
@@ -993,13 +993,13 @@ public static partial class OpenIddictValidationHandlers
                 return;
             }
 
-            else if (notification.IsRequestSkipped)
+            if (notification.IsRequestSkipped)
             {
                 context.SkipRequest();
                 return;
             }
 
-            else if (notification.IsRejected)
+            if (notification.IsRejected)
             {
                 if (context.RejectAccessToken)
                 {

test/OpenIddict.Abstractions.Tests/Primitives/OpenIddictConverterTests.cs

@@ -85,7 +85,7 @@ public class OpenIddictConverterTests
             return converter.Read(ref reader, type, options: null!);
         });
 
-        Assert.StartsWith(SR.GetResourceString(SR.ID0176), exception.Message);
+        Assert.StartsWith(SR.GetResourceString(SR.ID0176), exception.Message, StringComparison.Ordinal);
         Assert.Equal("typeToConvert", exception.ParamName);
     }
 

test/OpenIddict.Abstractions.Tests/Primitives/OpenIddictExtensionsTests.cs

@@ -46,7 +46,7 @@ public class OpenIddictExtensionsTests
         };
 
         // Act and assert
-        Assert.Equal(values, request.GetAcrValues());
+        Assert.Equal(values, request.GetAcrValues(), StringComparer.Ordinal);
     }
 
     [Fact]
@@ -107,7 +107,7 @@ public class OpenIddictExtensionsTests
         };
 
         // Act and assert
-        Assert.Equal(values, request.GetPromptValues());
+        Assert.Equal(values, request.GetPromptValues(), StringComparer.Ordinal);
     }
 
     [Fact]
@@ -168,7 +168,7 @@ public class OpenIddictExtensionsTests
         };
 
         // Act and assert
-        Assert.Equal(values, request.GetResponseTypes());
+        Assert.Equal(values, request.GetResponseTypes(), StringComparer.Ordinal);
     }
 
     [Fact]
@@ -203,7 +203,7 @@ public class OpenIddictExtensionsTests
         };
 
         // Act and assert
-        Assert.Equal(scopes, request.GetScopes());
+        Assert.Equal(scopes, request.GetScopes(), StringComparer.Ordinal);
     }
 
     [Fact]
@@ -1091,7 +1091,7 @@ public class OpenIddictExtensionsTests
         claim.Properties[Properties.Destinations] = destination!;
 
         // Act and assert
-        Assert.Equal(destinations, claim.GetDestinations());
+        Assert.Equal(destinations, claim.GetDestinations(), StringComparer.Ordinal);
     }
 
     [Fact]
@@ -1185,7 +1185,7 @@ public class OpenIddictExtensionsTests
         var exception = Assert.Throws<ArgumentException>(() => claim.SetDestinations(destination!));
 
         Assert.Equal("destinations", exception.ParamName);
-        Assert.StartsWith(SR.GetResourceString(SR.ID0182), exception.Message);
+        Assert.StartsWith(SR.GetResourceString(SR.ID0182), exception.Message, StringComparison.Ordinal);
     }
 
     [Theory]
@@ -1606,7 +1606,7 @@ public class OpenIddictExtensionsTests
         identity.AddClaim(new Claim(Claims.ClientId, "B56BF6CE-8D8C-4290-A0E7-A4F8EE0A9FC4"));
 
         // Act
-        var clone = identity.Clone(claim => claim.Type == Claims.Name);
+        var clone = identity.Clone(claim => claim.Type is Claims.Name);
         clone.AddClaim(new Claim("clone_claim", "value"));
 
         // Assert
@@ -1626,7 +1626,7 @@ public class OpenIddictExtensionsTests
         var principal = new ClaimsPrincipal(identity);
 
         // Act
-        var clone = principal.Clone(claim => claim.Type == Claims.Name);
+        var clone = principal.Clone(claim => claim.Type is Claims.Name);
         ((ClaimsIdentity) clone.Identity!).AddClaim(new Claim("clone_claim", "value"));
 
         // Assert
@@ -1645,7 +1645,7 @@ public class OpenIddictExtensionsTests
         identity.AddClaim(new Claim(Claims.Subject, "D8F1A010-BD46-4F8F-AD4E-05582307F8F4"));
 
         // Act
-        var clone = identity.Clone(claim => claim.Type == Claims.Name);
+        var clone = identity.Clone(claim => claim.Type is Claims.Name);
 
         // Assert
         Assert.Single(clone.Claims);
@@ -1663,7 +1663,7 @@ public class OpenIddictExtensionsTests
         var principal = new ClaimsPrincipal(identity);
 
         // Act
-        var clone = principal.Clone(claim => claim.Type == Claims.Name);
+        var clone = principal.Clone(claim => claim.Type is Claims.Name);
 
         // Assert
         Assert.Single(clone.Claims);
@@ -1683,7 +1683,7 @@ public class OpenIddictExtensionsTests
         identity.Actor.AddClaim(new Claim(Claims.Subject, "D8F1A010-BD46-4F8F-AD4E-05582307F8F4"));
 
         // Act
-        var clone = identity.Clone(claim => claim.Type == Claims.Name);
+        var clone = identity.Clone(claim => claim.Type is Claims.Name);
 
         // Assert
         Assert.Single(clone.Actor!.Claims);
@@ -1704,7 +1704,7 @@ public class OpenIddictExtensionsTests
         var principal = new ClaimsPrincipal(identity);
 
         // Act
-        var clone = principal.Clone(claim => claim.Type == Claims.Name);
+        var clone = principal.Clone(claim => claim.Type is Claims.Name);
 
         // Assert
         Assert.Single(((ClaimsIdentity) clone.Identity!).Actor!.Claims);
@@ -1746,7 +1746,7 @@ public class OpenIddictExtensionsTests
         var exception = Assert.Throws<ArgumentException>(() => principal.AddClaim(Claims.Name, "Bob le Bricoleur"));
 
         Assert.Equal("principal", exception.ParamName);
-        Assert.StartsWith(SR.GetResourceString(SR.ID0286), exception.Message);
+        Assert.StartsWith(SR.GetResourceString(SR.ID0286), exception.Message, StringComparison.Ordinal);
     }
 
     [Theory]
@@ -1837,7 +1837,7 @@ public class OpenIddictExtensionsTests
         var exception = Assert.Throws<ArgumentException>(() => principal.AddClaim(Claims.Name, true));
 
         Assert.Equal("principal", exception.ParamName);
-        Assert.StartsWith(SR.GetResourceString(SR.ID0286), exception.Message);
+        Assert.StartsWith(SR.GetResourceString(SR.ID0286), exception.Message, StringComparison.Ordinal);
     }
 
     [Theory]
@@ -1928,7 +1928,7 @@ public class OpenIddictExtensionsTests
         var exception = Assert.Throws<ArgumentException>(() => principal.AddClaim(Claims.Name, 42L));
 
         Assert.Equal("principal", exception.ParamName);
-        Assert.StartsWith(SR.GetResourceString(SR.ID0286), exception.Message);
+        Assert.StartsWith(SR.GetResourceString(SR.ID0286), exception.Message, StringComparison.Ordinal);
     }
 
     [Theory]
@@ -1992,7 +1992,7 @@ public class OpenIddictExtensionsTests
         var identity = (ClaimsIdentity) null!;
 
         // Act and assert
-        var exception = Assert.Throws<ArgumentNullException>(() => identity.AddClaim(Claims.Name, new Dictionary<string, string?>()));
+        var exception = Assert.Throws<ArgumentNullException>(() => identity.AddClaim(Claims.Name, new Dictionary<string, string?>(StringComparer.Ordinal)));
 
         Assert.Equal("identity", exception.ParamName);
     }
@@ -2004,7 +2004,7 @@ public class OpenIddictExtensionsTests
         var principal = (ClaimsPrincipal) null!;
 
         // Act and assert
-        var exception = Assert.Throws<ArgumentNullException>(() => principal.AddClaim(Claims.Name, new Dictionary<string, string?>()));
+        var exception = Assert.Throws<ArgumentNullException>(() => principal.AddClaim(Claims.Name, new Dictionary<string, string?>(StringComparer.Ordinal)));
 
         Assert.Equal("principal", exception.ParamName);
     }
@@ -2016,10 +2016,10 @@ public class OpenIddictExtensionsTests
         var principal = new ClaimsPrincipal();
 
         // Act and assert
-        var exception = Assert.Throws<ArgumentException>(() => principal.AddClaim(Claims.Name, new Dictionary<string, string?>()));
+        var exception = Assert.Throws<ArgumentException>(() => principal.AddClaim(Claims.Name, new Dictionary<string, string?>(StringComparer.Ordinal)));
 
         Assert.Equal("principal", exception.ParamName);
-        Assert.StartsWith(SR.GetResourceString(SR.ID0286), exception.Message);
+        Assert.StartsWith(SR.GetResourceString(SR.ID0286), exception.Message, StringComparison.Ordinal);
     }
 
     [Theory]
@@ -2031,7 +2031,7 @@ public class OpenIddictExtensionsTests
         var identity = new ClaimsIdentity();
 
         // Act and assert
-        var exception = Assert.ThrowsAny<ArgumentException>(() => identity.AddClaim(type!, new Dictionary<string, string?>()));
+        var exception = Assert.ThrowsAny<ArgumentException>(() => identity.AddClaim(type!, new Dictionary<string, string?>(StringComparer.Ordinal)));
 
         Assert.Equal("type", exception.ParamName);
     }
@@ -2045,7 +2045,7 @@ public class OpenIddictExtensionsTests
         var principal = new ClaimsPrincipal(new ClaimsIdentity());
 
         // Act and assert
-        var exception = Assert.ThrowsAny<ArgumentException>(() => principal.AddClaim(type!, new Dictionary<string, string?>()));
+        var exception = Assert.ThrowsAny<ArgumentException>(() => principal.AddClaim(type!, new Dictionary<string, string?>(StringComparer.Ordinal)));
 
         Assert.Equal("type", exception.ParamName);
     }
@@ -2057,7 +2057,7 @@ public class OpenIddictExtensionsTests
         var identity = new ClaimsIdentity();
 
         // Act
-        identity.AddClaim("type", new Dictionary<string, string?>
+        identity.AddClaim("type", new Dictionary<string, string?>(StringComparer.Ordinal)
         {
             ["parameter"] = "value"
         });
@@ -2073,7 +2073,7 @@ public class OpenIddictExtensionsTests
         var principal = new ClaimsPrincipal(new ClaimsIdentity());
 
         // Act
-        principal.AddClaim("type", new Dictionary<string, string?>
+        principal.AddClaim("type", new Dictionary<string, string?>(StringComparer.Ordinal)
         {
             ["parameter"] = "value"
         });
@@ -2116,7 +2116,7 @@ public class OpenIddictExtensionsTests
         var exception = Assert.Throws<ArgumentException>(() => principal.AddClaim(Claims.Name, default(JsonElement)));
 
         Assert.Equal("principal", exception.ParamName);
-        Assert.StartsWith(SR.GetResourceString(SR.ID0286), exception.Message);
+        Assert.StartsWith(SR.GetResourceString(SR.ID0286), exception.Message, StringComparison.Ordinal);
     }
 
     [Theory]
@@ -2158,7 +2158,7 @@ public class OpenIddictExtensionsTests
             JsonSerializer.Deserialize<JsonElement>(@"[""Fabrikam"",""Contoso""]")));
 
         Assert.Equal("value", exception.ParamName);
-        Assert.StartsWith(SR.GetResourceString(SR.ID0185), exception.Message);
+        Assert.StartsWith(SR.GetResourceString(SR.ID0185), exception.Message, StringComparison.Ordinal);
     }
 
     [Fact]
@@ -2172,7 +2172,7 @@ public class OpenIddictExtensionsTests
             JsonSerializer.Deserialize<JsonElement>(@"[""Fabrikam"",""Contoso""]")));
 
         Assert.Equal("value", exception.ParamName);
-        Assert.StartsWith(SR.GetResourceString(SR.ID0185), exception.Message);
+        Assert.StartsWith(SR.GetResourceString(SR.ID0185), exception.Message, StringComparison.Ordinal);
     }
 
     [Fact]
@@ -2235,7 +2235,7 @@ public class OpenIddictExtensionsTests
         var exception = Assert.Throws<ArgumentException>(() => principal.AddClaim(Claims.Name, (JsonNode) null!));
 
         Assert.Equal("principal", exception.ParamName);
-        Assert.StartsWith(SR.GetResourceString(SR.ID0286), exception.Message);
+        Assert.StartsWith(SR.GetResourceString(SR.ID0286), exception.Message, StringComparison.Ordinal);
     }
 
     [Theory]
@@ -2301,7 +2301,7 @@ public class OpenIddictExtensionsTests
             new JsonArray(["Fabrikam", "Contoso"])));
 
         Assert.Equal("value", exception.ParamName);
-        Assert.StartsWith(SR.GetResourceString(SR.ID0185), exception.Message);
+        Assert.StartsWith(SR.GetResourceString(SR.ID0185), exception.Message, StringComparison.Ordinal);
     }
 
     [Fact]
@@ -2315,7 +2315,7 @@ public class OpenIddictExtensionsTests
             new JsonArray(["Fabrikam", "Contoso"])));
 
         Assert.Equal("value", exception.ParamName);
-        Assert.StartsWith(SR.GetResourceString(SR.ID0185), exception.Message);
+        Assert.StartsWith(SR.GetResourceString(SR.ID0185), exception.Message, StringComparison.Ordinal);
     }
 
     [Fact]
@@ -2378,7 +2378,7 @@ public class OpenIddictExtensionsTests
         var exception = Assert.Throws<ArgumentException>(() => principal.AddClaims("type", ["value1", "value2"]));
 
         Assert.Equal("principal", exception.ParamName);
-        Assert.StartsWith(SR.GetResourceString(SR.ID0286), exception.Message);
+        Assert.StartsWith(SR.GetResourceString(SR.ID0286), exception.Message, StringComparison.Ordinal);
     }
 
     [Theory]
@@ -2459,7 +2459,7 @@ public class OpenIddictExtensionsTests
         identity.AddClaims("TYPE", ["value1", "value2"]);
 
         // Assert
-        Assert.Equal<string>(["value1", "value2"], identity.GetClaims("type"));
+        Assert.Equal<string>(["value1", "value2"], identity.GetClaims("type"), StringComparer.Ordinal);
     }
 
     [Fact]
@@ -2472,7 +2472,7 @@ public class OpenIddictExtensionsTests
         principal.AddClaims("TYPE", ["value1", "value2"]);
 
         // Assert
-        Assert.Equal<string>(["value1", "value2"], principal.GetClaims("type"));
+        Assert.Equal<string>(["value1", "value2"], principal.GetClaims("type"), StringComparer.Ordinal);
     }
 
     [Fact]
@@ -2509,7 +2509,7 @@ public class OpenIddictExtensionsTests
         var exception = Assert.Throws<ArgumentException>(() => principal.AddClaims("type", default(JsonElement)));
 
         Assert.Equal("principal", exception.ParamName);
-        Assert.StartsWith(SR.GetResourceString(SR.ID0286), exception.Message);
+        Assert.StartsWith(SR.GetResourceString(SR.ID0286), exception.Message, StringComparison.Ordinal);
     }
 
     [Theory]
@@ -2551,7 +2551,7 @@ public class OpenIddictExtensionsTests
             JsonSerializer.Deserialize<JsonElement>(@"{""parameter"":""value""}")));
 
         Assert.Equal("value", exception.ParamName);
-        Assert.StartsWith(SR.GetResourceString(SR.ID0185), exception.Message);
+        Assert.StartsWith(SR.GetResourceString(SR.ID0185), exception.Message, StringComparison.Ordinal);
     }
 
     [Fact]
@@ -2565,7 +2565,7 @@ public class OpenIddictExtensionsTests
             JsonSerializer.Deserialize<JsonElement>(@"{""parameter"":""value""}")));
 
         Assert.Equal("value", exception.ParamName);
-        Assert.StartsWith(SR.GetResourceString(SR.ID0185), exception.Message);
+        Assert.StartsWith(SR.GetResourceString(SR.ID0185), exception.Message, StringComparison.Ordinal);
     }
 
     [Fact]
@@ -2629,7 +2629,7 @@ public class OpenIddictExtensionsTests
         identity.AddClaims("TYPE", JsonSerializer.Deserialize<JsonElement>(@"[""Fabrikam"",""Contoso""]"));
 
         // Assert
-        Assert.Equal<string>(["Fabrikam", "Contoso"], identity.GetClaims("type"));
+        Assert.Equal<string>(["Fabrikam", "Contoso"], identity.GetClaims("type"), StringComparer.Ordinal);
     }
 
     [Fact]
@@ -2642,7 +2642,7 @@ public class OpenIddictExtensionsTests
         principal.AddClaims("TYPE", JsonSerializer.Deserialize<JsonElement>(@"[""Fabrikam"",""Contoso""]"));
 
         // Assert
-        Assert.Equal<string>(["Fabrikam", "Contoso"], principal.GetClaims("type"));
+        Assert.Equal<string>(["Fabrikam", "Contoso"], principal.GetClaims("type"), StringComparer.Ordinal);
     }
 
     [Fact]
@@ -2679,7 +2679,7 @@ public class OpenIddictExtensionsTests
         var exception = Assert.Throws<ArgumentException>(() => principal.AddClaims("type", (JsonArray) null!));
 
         Assert.Equal("principal", exception.ParamName);
-        Assert.StartsWith(SR.GetResourceString(SR.ID0286), exception.Message);
+        Assert.StartsWith(SR.GetResourceString(SR.ID0286), exception.Message, StringComparison.Ordinal);
     }
 
     [Theory]
@@ -2795,7 +2795,7 @@ public class OpenIddictExtensionsTests
         identity.AddClaims("TYPE", new JsonArray(["Fabrikam", "Contoso"]));
 
         // Assert
-        Assert.Equal<string>(["Fabrikam", "Contoso"], identity.GetClaims("type"));
+        Assert.Equal<string>(["Fabrikam", "Contoso"], identity.GetClaims("type"), StringComparer.Ordinal);
     }
 
     [Fact]
@@ -2808,7 +2808,7 @@ public class OpenIddictExtensionsTests
         principal.AddClaims("TYPE", new JsonArray(["Fabrikam", "Contoso"]));
 
         // Assert
-        Assert.Equal<string>(["Fabrikam", "Contoso"], principal.GetClaims("type"));
+        Assert.Equal<string>(["Fabrikam", "Contoso"], principal.GetClaims("type"), StringComparer.Ordinal);
     }
 
     [Fact]
@@ -3255,7 +3255,7 @@ public class OpenIddictExtensionsTests
         var exception = Assert.Throws<ArgumentException>(() => principal.SetClaim("type", "value"));
 
         Assert.Equal("principal", exception.ParamName);
-        Assert.StartsWith(SR.GetResourceString(SR.ID0286), exception.Message);
+        Assert.StartsWith(SR.GetResourceString(SR.ID0286), exception.Message, StringComparison.Ordinal);
     }
 
     [Theory]
@@ -3408,7 +3408,7 @@ public class OpenIddictExtensionsTests
         var exception = Assert.Throws<ArgumentException>(() => principal.SetClaim("type", true));
 
         Assert.Equal("principal", exception.ParamName);
-        Assert.StartsWith(SR.GetResourceString(SR.ID0286), exception.Message);
+        Assert.StartsWith(SR.GetResourceString(SR.ID0286), exception.Message, StringComparison.Ordinal);
     }
 
     [Theory]
@@ -3561,7 +3561,7 @@ public class OpenIddictExtensionsTests
         var exception = Assert.Throws<ArgumentException>(() => principal.SetClaim("type", 42L));
 
         Assert.Equal("principal", exception.ParamName);
-        Assert.StartsWith(SR.GetResourceString(SR.ID0286), exception.Message);
+        Assert.StartsWith(SR.GetResourceString(SR.ID0286), exception.Message, StringComparison.Ordinal);
     }
 
     [Theory]
@@ -3687,7 +3687,7 @@ public class OpenIddictExtensionsTests
         var identity = (ClaimsIdentity) null!;
 
         // Act and assert
-        var exception = Assert.Throws<ArgumentNullException>(() => identity.SetClaim("type", new Dictionary<string, string?>()));
+        var exception = Assert.Throws<ArgumentNullException>(() => identity.SetClaim("type", new Dictionary<string, string?>(StringComparer.Ordinal)));
 
         Assert.Equal("identity", exception.ParamName);
     }
@@ -3699,7 +3699,7 @@ public class OpenIddictExtensionsTests
         var principal = (ClaimsPrincipal) null!;
 
         // Act and assert
-        var exception = Assert.Throws<ArgumentNullException>(() => principal.SetClaim("type", new Dictionary<string, string?>()));
+        var exception = Assert.Throws<ArgumentNullException>(() => principal.SetClaim("type", new Dictionary<string, string?>(StringComparer.Ordinal)));
 
         Assert.Equal("principal", exception.ParamName);
     }
@@ -3711,13 +3711,13 @@ public class OpenIddictExtensionsTests
         var principal = new ClaimsPrincipal();
 
         // Act and assert
-        var exception = Assert.Throws<ArgumentException>(() => principal.SetClaim("type", new Dictionary<string, string?>
+        var exception = Assert.Throws<ArgumentException>(() => principal.SetClaim("type", new Dictionary<string, string?>(StringComparer.Ordinal)
         {
             ["parameter"] = "value"
         }));
 
         Assert.Equal("principal", exception.ParamName);
-        Assert.StartsWith(SR.GetResourceString(SR.ID0286), exception.Message);
+        Assert.StartsWith(SR.GetResourceString(SR.ID0286), exception.Message, StringComparison.Ordinal);
     }
 
     [Theory]
@@ -3729,7 +3729,7 @@ public class OpenIddictExtensionsTests
         var identity = new ClaimsIdentity();
 
         // Act and assert
-        var exception = Assert.ThrowsAny<ArgumentException>(() => identity.SetClaim(type!, new Dictionary<string, string?>()));
+        var exception = Assert.ThrowsAny<ArgumentException>(() => identity.SetClaim(type!, new Dictionary<string, string?>(StringComparer.Ordinal)));
 
         Assert.Equal("type", exception.ParamName);
     }
@@ -3743,7 +3743,7 @@ public class OpenIddictExtensionsTests
         var principal = new ClaimsPrincipal(new ClaimsIdentity());
 
         // Act and assert
-        var exception = Assert.ThrowsAny<ArgumentException>(() => principal.SetClaim(type!, new Dictionary<string, string?>()));
+        var exception = Assert.ThrowsAny<ArgumentException>(() => principal.SetClaim(type!, new Dictionary<string, string?>(StringComparer.Ordinal)));
 
         Assert.Equal("type", exception.ParamName);
     }
@@ -3756,7 +3756,7 @@ public class OpenIddictExtensionsTests
         identity.AddClaim("type", "value1");
 
         // Act
-        identity.SetClaim("type", new Dictionary<string, string?>
+        identity.SetClaim("type", new Dictionary<string, string?>(StringComparer.Ordinal)
         {
             ["parameter"] = "value"
         }, "issuer");
@@ -3776,7 +3776,7 @@ public class OpenIddictExtensionsTests
         principal.AddClaim("type", "value1");
 
         // Act
-        principal.SetClaim("type", new Dictionary<string, string?>
+        principal.SetClaim("type", new Dictionary<string, string?>(StringComparer.Ordinal)
         {
             ["parameter"] = "value"
         }, "issuer");
@@ -3795,7 +3795,7 @@ public class OpenIddictExtensionsTests
         var identity = new ClaimsIdentity();
 
         // Act
-        identity.SetClaim("TYPE", new Dictionary<string, string?>
+        identity.SetClaim("TYPE", new Dictionary<string, string?>(StringComparer.Ordinal)
         {
             ["parameter"] = "value"
         });
@@ -3811,7 +3811,7 @@ public class OpenIddictExtensionsTests
         var principal = new ClaimsPrincipal(new ClaimsIdentity());
 
         // Act
-        principal.SetClaim("TYPE", new Dictionary<string, string?>
+        principal.SetClaim("TYPE", new Dictionary<string, string?>(StringComparer.Ordinal)
         {
             ["parameter"] = "value"
         });
@@ -3828,7 +3828,7 @@ public class OpenIddictExtensionsTests
         identity.AddClaim("type", "value");
 
         // Act
-        identity.SetClaim("type", new Dictionary<string, string?>());
+        identity.SetClaim("type", new Dictionary<string, string?>(StringComparer.Ordinal));
 
         // Assert
         Assert.Null(identity.GetClaim("type"));
@@ -3842,7 +3842,7 @@ public class OpenIddictExtensionsTests
         principal.AddClaim("type", "value");
 
         // Act
-        principal.SetClaim("type", new Dictionary<string, string?>());
+        principal.SetClaim("type", new Dictionary<string, string?>(StringComparer.Ordinal));
 
         // Assert
         Assert.Null(principal.GetClaim("type"));
@@ -3883,7 +3883,7 @@ public class OpenIddictExtensionsTests
             JsonSerializer.Deserialize<JsonElement>(@"{""parameter"":""value""}")));
 
         Assert.Equal("principal", exception.ParamName);
-        Assert.StartsWith(SR.GetResourceString(SR.ID0286), exception.Message);
+        Assert.StartsWith(SR.GetResourceString(SR.ID0286), exception.Message, StringComparison.Ordinal);
     }
 
     [Theory]
@@ -4091,7 +4091,7 @@ public class OpenIddictExtensionsTests
             new JsonObject { ["parameter"] = "value" }));
 
         Assert.Equal("principal", exception.ParamName);
-        Assert.StartsWith(SR.GetResourceString(SR.ID0286), exception.Message);
+        Assert.StartsWith(SR.GetResourceString(SR.ID0286), exception.Message, StringComparison.Ordinal);
     }
 
     [Theory]
@@ -4298,7 +4298,7 @@ public class OpenIddictExtensionsTests
         var exception = Assert.Throws<ArgumentException>(() => principal.SetClaims("type", ["value1", "value2"]));
 
         Assert.Equal("principal", exception.ParamName);
-        Assert.StartsWith(SR.GetResourceString(SR.ID0286), exception.Message);
+        Assert.StartsWith(SR.GetResourceString(SR.ID0286), exception.Message, StringComparison.Ordinal);
     }
 
     [Theory]
@@ -4378,7 +4378,7 @@ public class OpenIddictExtensionsTests
         identity.SetClaims("TYPE", ["value1", "value2"]);
 
         // Assert
-        Assert.Equal<string>(["value1", "value2"], identity.GetClaims("type"));
+        Assert.Equal<string>(["value1", "value2"], identity.GetClaims("type"), StringComparer.Ordinal);
     }
 
     [Fact]
@@ -4391,7 +4391,7 @@ public class OpenIddictExtensionsTests
         principal.SetClaims("TYPE", ["value1", "value2"]);
 
         // Assert
-        Assert.Equal<string>(["value1", "value2"], principal.GetClaims("type"));
+        Assert.Equal<string>(["value1", "value2"], principal.GetClaims("type"), StringComparer.Ordinal);
     }
 
     [Fact]
@@ -4457,7 +4457,7 @@ public class OpenIddictExtensionsTests
             JsonSerializer.Deserialize<JsonElement>(@"[""Fabrikam"",""Contoso""]")));
 
         Assert.Equal("principal", exception.ParamName);
-        Assert.StartsWith(SR.GetResourceString(SR.ID0286), exception.Message);
+        Assert.StartsWith(SR.GetResourceString(SR.ID0286), exception.Message, StringComparison.Ordinal);
     }
 
     [Theory]
@@ -4537,7 +4537,7 @@ public class OpenIddictExtensionsTests
         identity.SetClaims("TYPE", JsonSerializer.Deserialize<JsonElement>(@"[""Fabrikam"",""Contoso""]"));
 
         // Assert
-        Assert.Equal<string>(["Fabrikam", "Contoso"], identity.GetClaims("type"));
+        Assert.Equal<string>(["Fabrikam", "Contoso"], identity.GetClaims("type"), StringComparer.Ordinal);
     }
 
     [Fact]
@@ -4550,7 +4550,7 @@ public class OpenIddictExtensionsTests
         principal.SetClaims("TYPE", JsonSerializer.Deserialize<JsonElement>(@"[""Fabrikam"",""Contoso""]"));
 
         // Assert
-        Assert.Equal<string>(["Fabrikam", "Contoso"], principal.GetClaims("type"));
+        Assert.Equal<string>(["Fabrikam", "Contoso"], principal.GetClaims("type"), StringComparer.Ordinal);
     }
 
     [Fact]
@@ -4670,7 +4670,7 @@ public class OpenIddictExtensionsTests
             new JsonArray("Fabrikam", "Contoso")));
 
         Assert.Equal("principal", exception.ParamName);
-        Assert.StartsWith(SR.GetResourceString(SR.ID0286), exception.Message);
+        Assert.StartsWith(SR.GetResourceString(SR.ID0286), exception.Message, StringComparison.Ordinal);
     }
 
     [Theory]
@@ -4774,7 +4774,7 @@ public class OpenIddictExtensionsTests
         identity.SetClaims("TYPE", new JsonArray("Fabrikam", "Contoso"));
 
         // Assert
-        Assert.Equal<string>(["Fabrikam", "Contoso"], identity.GetClaims("type"));
+        Assert.Equal<string>(["Fabrikam", "Contoso"], identity.GetClaims("type"), StringComparer.Ordinal);
     }
 
     [Fact]
@@ -4787,7 +4787,7 @@ public class OpenIddictExtensionsTests
         principal.SetClaims("TYPE", new JsonArray("Fabrikam", "Contoso"));
 
         // Assert
-        Assert.Equal<string>(["Fabrikam", "Contoso"], principal.GetClaims("type"));
+        Assert.Equal<string>(["Fabrikam", "Contoso"], principal.GetClaims("type"), StringComparer.Ordinal);
     }
 
     [Fact]
@@ -4999,7 +4999,7 @@ public class OpenIddictExtensionsTests
         identity.SetClaims(Claims.Private.Audience, audience.ToImmutableArray());
 
         // Act and assert
-        Assert.Equal(audiences, identity.GetAudiences());
+        Assert.Equal(audiences, identity.GetAudiences(), StringComparer.Ordinal);
     }
 
     [Theory]
@@ -5015,7 +5015,7 @@ public class OpenIddictExtensionsTests
         principal.SetClaims(Claims.Private.Audience, audience.ToImmutableArray());
 
         // Act and assert
-        Assert.Equal(audiences, principal.GetAudiences());
+        Assert.Equal(audiences, principal.GetAudiences(), StringComparer.Ordinal);
     }
 
     [Fact]
@@ -5055,7 +5055,7 @@ public class OpenIddictExtensionsTests
         identity.SetClaims(Claims.Private.Presenter, presenter.ToImmutableArray());
 
         // Act and assert
-        Assert.Equal(presenters, identity.GetPresenters());
+        Assert.Equal(presenters, identity.GetPresenters(), StringComparer.Ordinal);
     }
 
     [Theory]
@@ -5071,7 +5071,7 @@ public class OpenIddictExtensionsTests
         principal.SetClaims(Claims.Private.Presenter, presenter.ToImmutableArray());
 
         // Act and assert
-        Assert.Equal(presenters, principal.GetPresenters());
+        Assert.Equal(presenters, principal.GetPresenters(), StringComparer.Ordinal);
     }
 
     [Fact]
@@ -5111,7 +5111,7 @@ public class OpenIddictExtensionsTests
         identity.SetClaims(Claims.Private.Resource, resource.ToImmutableArray());
 
         // Act and assert
-        Assert.Equal(resources, identity.GetResources());
+        Assert.Equal(resources, identity.GetResources(), StringComparer.Ordinal);
     }
 
     [Theory]
@@ -5127,7 +5127,7 @@ public class OpenIddictExtensionsTests
         principal.SetClaims(Claims.Private.Resource, resource.ToImmutableArray());
 
         // Act and assert
-        Assert.Equal(resources, principal.GetResources());
+        Assert.Equal(resources, principal.GetResources(), StringComparer.Ordinal);
     }
 
     [Fact]
@@ -5167,7 +5167,7 @@ public class OpenIddictExtensionsTests
         identity.SetClaims(Claims.Private.Scope, scope.ToImmutableArray());
 
         // Act and assert
-        Assert.Equal(scopes, identity.GetScopes());
+        Assert.Equal(scopes, identity.GetScopes(), StringComparer.Ordinal);
     }
 
     [Theory]
@@ -5183,7 +5183,7 @@ public class OpenIddictExtensionsTests
         principal.SetClaims(Claims.Private.Scope, scope.ToImmutableArray());
 
         // Act and assert
-        Assert.Equal(scopes, principal.GetScopes());
+        Assert.Equal(scopes, principal.GetScopes(), StringComparer.Ordinal);
     }
 
     [Fact]
@@ -6430,7 +6430,7 @@ public class OpenIddictExtensionsTests
         identity.SetAudiences(audiences);
 
         // Assert
-        Assert.Equal(audience, identity.GetClaims(Claims.Private.Audience));
+        Assert.Equal(audience, identity.GetClaims(Claims.Private.Audience), StringComparer.Ordinal);
     }
 
     [Theory]
@@ -6449,7 +6449,7 @@ public class OpenIddictExtensionsTests
         principal.SetAudiences(audiences);
 
         // Assert
-        Assert.Equal(audience, principal.GetClaims(Claims.Private.Audience));
+        Assert.Equal(audience, principal.GetClaims(Claims.Private.Audience), StringComparer.Ordinal);
     }
 
     [Fact]
@@ -6492,7 +6492,7 @@ public class OpenIddictExtensionsTests
         identity.SetPresenters(presenters);
 
         // Assert
-        Assert.Equal(presenter, identity.GetClaims(Claims.Private.Presenter));
+        Assert.Equal(presenter, identity.GetClaims(Claims.Private.Presenter), StringComparer.Ordinal);
     }
 
     [Theory]
@@ -6511,7 +6511,7 @@ public class OpenIddictExtensionsTests
         principal.SetPresenters(presenters);
 
         // Assert
-        Assert.Equal(presenter, principal.GetClaims(Claims.Private.Presenter));
+        Assert.Equal(presenter, principal.GetClaims(Claims.Private.Presenter), StringComparer.Ordinal);
     }
 
     [Fact]
@@ -6554,7 +6554,7 @@ public class OpenIddictExtensionsTests
         identity.SetResources(resources);
 
         // Assert
-        Assert.Equal(resource, identity.GetClaims(Claims.Private.Resource));
+        Assert.Equal(resource, identity.GetClaims(Claims.Private.Resource), StringComparer.Ordinal);
     }
 
     [Theory]
@@ -6573,7 +6573,7 @@ public class OpenIddictExtensionsTests
         principal.SetResources(resources);
 
         // Assert
-        Assert.Equal(resource, principal.GetClaims(Claims.Private.Resource));
+        Assert.Equal(resource, principal.GetClaims(Claims.Private.Resource), StringComparer.Ordinal);
     }
 
     [Fact]
@@ -6616,7 +6616,7 @@ public class OpenIddictExtensionsTests
         identity.SetScopes(scopes);
 
         // Assert
-        Assert.Equal(scope, identity.GetClaims(Claims.Private.Scope));
+        Assert.Equal(scope, identity.GetClaims(Claims.Private.Scope), StringComparer.Ordinal);
     }
 
     [Theory]
@@ -6635,7 +6635,7 @@ public class OpenIddictExtensionsTests
         principal.SetScopes(scopes);
 
         // Assert
-        Assert.Equal(scope, principal.GetClaims(Claims.Private.Scope));
+        Assert.Equal(scope, principal.GetClaims(Claims.Private.Scope), StringComparer.Ordinal);
     }
 
     [Fact]

test/OpenIddict.Abstractions.Tests/Primitives/OpenIddictMessageTests.cs

@@ -25,7 +25,7 @@ public class OpenIddictMessageTests
         });
 
         Assert.Equal("parameters", exception.ParamName);
-        Assert.StartsWith(SR.GetResourceString(SR.ID0189), exception.Message);
+        Assert.StartsWith(SR.GetResourceString(SR.ID0189), exception.Message, StringComparison.Ordinal);
     }
 
     [Fact]
@@ -42,7 +42,7 @@ public class OpenIddictMessageTests
         });
 
         Assert.Equal("parameters", exception.ParamName);
-        Assert.StartsWith(SR.GetResourceString(SR.ID0191), exception.Message);
+        Assert.StartsWith(SR.GetResourceString(SR.ID0191), exception.Message, StringComparison.Ordinal);
     }
 
     [Fact]
@@ -253,7 +253,7 @@ public class OpenIddictMessageTests
     public void GetParameters_EnumeratesParameters()
     {
         // Arrange
-        var parameters = new Dictionary<string, OpenIddictParameter>
+        var parameters = new Dictionary<string, OpenIddictParameter>(StringComparer.Ordinal)
         {
             ["int"] = int.MaxValue,
             ["long"] = long.MaxValue,
@@ -483,7 +483,7 @@ public class OpenIddictMessageTests
 
         // Act and assert
         var element = JsonSerializer.Deserialize<JsonElement>(message.ToString());
-        Assert.DoesNotContain("secret value", message.ToString());
+        Assert.DoesNotContain("secret value", message.ToString(), StringComparison.Ordinal);
         Assert.Equal("[redacted]", element.GetProperty(parameter).GetString());
     }
 

test/OpenIddict.Abstractions.Tests/Primitives/OpenIddictParameterTests.cs

@@ -316,12 +316,12 @@ public class OpenIddictParameterTests
             ["field"] = new JsonArray(0, 1, 2)
         })));
 
-        Assert.True(parameter.Equals(new OpenIddictParameter(JsonValue.Create(new Dictionary<string, object>
+        Assert.True(parameter.Equals(new OpenIddictParameter(JsonValue.Create(new Dictionary<string, object>(StringComparer.Ordinal)
         {
             ["field"] = new JsonArray(0, 1, 2, 3)
         }))));
 
-        Assert.True(parameter.Equals(new OpenIddictParameter(JsonValue.Create(new Dictionary<string, object>
+        Assert.True(parameter.Equals(new OpenIddictParameter(JsonValue.Create(new Dictionary<string, object>(StringComparer.Ordinal)
         {
             ["field"] = new[] { 0, 1, 2, 3 }
         }))));
@@ -445,12 +445,12 @@ public class OpenIddictParameterTests
         Assert.Equal(1, new OpenIddictParameter(true).GetHashCode());
         Assert.Equal(0, new OpenIddictParameter(false).GetHashCode());
         Assert.Equal(42.GetHashCode(), new OpenIddictParameter(42).GetHashCode());
-        Assert.Equal("Fabrikam".GetHashCode(), new OpenIddictParameter("Fabrikam").GetHashCode());
+        Assert.Equal("Fabrikam".GetHashCode(StringComparison.Ordinal), new OpenIddictParameter("Fabrikam").GetHashCode());
 
         Assert.NotEqual(1, new OpenIddictParameter("true").GetHashCode());
         Assert.NotEqual(0, new OpenIddictParameter("false").GetHashCode());
         Assert.NotEqual(42.GetHashCode(), new OpenIddictParameter("42").GetHashCode());
-        Assert.NotEqual("Fabrikam".GetHashCode(), new OpenIddictParameter(42).GetHashCode());
+        Assert.NotEqual("Fabrikam".GetHashCode(StringComparison.Ordinal), new OpenIddictParameter(42).GetHashCode());
     }
 
     [Fact]
@@ -851,7 +851,7 @@ public class OpenIddictParameterTests
     public void GetNamedParameters_ReturnsExpectedParametersForJsonObjectElements()
     {
         // Arrange
-        var parameters = new Dictionary<string, string?>
+        var parameters = new Dictionary<string, string?>(StringComparer.Ordinal)
         {
             ["parameter"] = "value"
         };
@@ -860,14 +860,14 @@ public class OpenIddictParameterTests
             JsonSerializer.Deserialize<JsonElement>(@"{""parameter"":""value""}"));
 
         // Act and assert
-        Assert.Equal(parameters, parameter.GetNamedParameters().ToDictionary(pair => pair.Key, pair => (string?) pair.Value));
+        Assert.Equal(parameters, parameter.GetNamedParameters().ToDictionary(pair => pair.Key, pair => (string?) pair.Value, StringComparer.Ordinal));
     }
 
     [Fact]
     public void GetNamedParameters_ReturnsExpectedParametersForJsonObjectNodes()
     {
         // Arrange
-        var parameters = new Dictionary<string, string?>
+        var parameters = new Dictionary<string, string?>(StringComparer.Ordinal)
         {
             ["parameter"] = "value"
         };
@@ -878,7 +878,7 @@ public class OpenIddictParameterTests
         });
 
         // Act and assert
-        Assert.Equal(parameters, parameter.GetNamedParameters().ToDictionary(pair => pair.Key, pair => (string?) pair.Value));
+        Assert.Equal(parameters, parameter.GetNamedParameters().ToDictionary(pair => pair.Key, pair => (string?) pair.Value, StringComparer.Ordinal));
     }
 
     [Fact]
@@ -926,7 +926,7 @@ public class OpenIddictParameterTests
 
         // Act and assert
         Assert.Equal(parameters, from element in parameter.GetUnnamedParameters()
-                                 select (string?) element);
+                                 select (string?) element, StringComparer.Ordinal);
     }
 
     [Fact]
@@ -965,7 +965,7 @@ public class OpenIddictParameterTests
 
         // Act and assert
         Assert.Equal(parameters, from element in parameter.GetUnnamedParameters()
-                                 select (string?) element);
+                                 select (string?) element, StringComparer.Ordinal);
     }
 
     [Fact]
@@ -982,7 +982,7 @@ public class OpenIddictParameterTests
 
         // Act and assert
         Assert.Equal(parameters, from element in parameter.GetUnnamedParameters()
-                                 select (string?) element);
+                                 select (string?) element, StringComparer.Ordinal);
     }
 
     [Fact]

test/OpenIddict.Client.Tests/OpenIddictClientBuilderTests.cs

@@ -1196,7 +1196,7 @@ public class OpenIddictClientBuilderTests
         // Act and assert
         var exception = Assert.Throws<ArgumentException>(() => builder.SetPostLogoutRedirectionEndpointUris(new Uri(uri)));
         Assert.Equal("uris", exception.ParamName);
-        Assert.Contains(SR.GetResourceString(SR.ID0072), exception.Message);
+        Assert.Contains(SR.GetResourceString(SR.ID0072), exception.Message, StringComparison.Ordinal);
     }
 
     [Theory]
@@ -1210,7 +1210,7 @@ public class OpenIddictClientBuilderTests
         // Act and assert
         var exception = Assert.Throws<ArgumentException>(() => builder.SetPostLogoutRedirectionEndpointUris(new Uri(uri, UriKind.RelativeOrAbsolute)));
         Assert.Equal("uris", exception.ParamName);
-        Assert.Contains(SR.FormatID0081("~"), exception.Message);
+        Assert.Contains(SR.FormatID0081("~"), exception.Message, StringComparison.Ordinal);
     }
 
     [Fact]
@@ -1280,7 +1280,7 @@ public class OpenIddictClientBuilderTests
         // Act and assert
         var exception = Assert.Throws<ArgumentException>(() => builder.SetRedirectionEndpointUris(new Uri(uri)));
         Assert.Equal("uris", exception.ParamName);
-        Assert.Contains(SR.GetResourceString(SR.ID0072), exception.Message);
+        Assert.Contains(SR.GetResourceString(SR.ID0072), exception.Message, StringComparison.Ordinal);
     }
 
     [Theory]
@@ -1294,7 +1294,7 @@ public class OpenIddictClientBuilderTests
         // Act and assert
         var exception = Assert.Throws<ArgumentException>(() => builder.SetRedirectionEndpointUris(new Uri(uri, UriKind.RelativeOrAbsolute)));
         Assert.Equal("uris", exception.ParamName);
-        Assert.Contains(SR.FormatID0081("~"), exception.Message);
+        Assert.Contains(SR.FormatID0081("~"), exception.Message, StringComparison.Ordinal);
     }
 
     [Fact]

test/OpenIddict.Client.Tests/OpenIddictClientConfigurationTests.cs

@@ -175,7 +175,7 @@ public class OpenIddictClientConfigurationTests
         var result = configuration.Validate(name: null, options);
 
         // Assert
-        Assert.Contains(SR.GetResourceString(SR.ID0075), result.Failures!);
+        Assert.Contains(SR.GetResourceString(SR.ID0075), result.Failures!, StringComparer.Ordinal);
     }
 
     [Fact]
@@ -196,7 +196,7 @@ public class OpenIddictClientConfigurationTests
         var result = configuration.Validate(name: null, options);
 
         // Assert
-        Assert.Contains(SR.GetResourceString(SR.ID0455), result.Failures!);
+        Assert.Contains(SR.GetResourceString(SR.ID0455), result.Failures!, StringComparer.Ordinal);
     }
 
     [Fact]
@@ -216,7 +216,7 @@ public class OpenIddictClientConfigurationTests
         var result = configuration.Validate(name: null, options);
 
         // Assert
-        Assert.Contains(SR.GetResourceString(SR.ID0521), result.Failures!);
+        Assert.Contains(SR.GetResourceString(SR.ID0521), result.Failures!, StringComparer.Ordinal);
     }
 
     [Fact]
@@ -237,7 +237,7 @@ public class OpenIddictClientConfigurationTests
         var result = configuration.Validate(name: null, options);
 
         // Assert
-        Assert.Contains(SR.GetResourceString(SR.ID0136), result.Failures!);
+        Assert.Contains(SR.GetResourceString(SR.ID0136), result.Failures!, StringComparer.Ordinal);
     }
 
     [Fact]
@@ -258,7 +258,7 @@ public class OpenIddictClientConfigurationTests
         var result = configuration.Validate(name: null, options);
 
         // Assert
-        Assert.Contains(SR.GetResourceString(SR.ID0137), result.Failures!);
+        Assert.Contains(SR.GetResourceString(SR.ID0137), result.Failures!, StringComparer.Ordinal);
     }
 
     [Fact]
@@ -280,7 +280,7 @@ public class OpenIddictClientConfigurationTests
         var result = configuration.Validate(name: null, options);
 
         // Assert
-        Assert.Contains(SR.GetResourceString(SR.ID0395), result.Failures!);
+        Assert.Contains(SR.GetResourceString(SR.ID0395), result.Failures!, StringComparer.Ordinal);
     }
 
     [Fact]
@@ -300,7 +300,7 @@ public class OpenIddictClientConfigurationTests
         var result = configuration.Validate(name: null, options);
 
         // Assert
-        Assert.Contains(SR.GetResourceString(SR.ID0522), result.Failures!);
+        Assert.Contains(SR.GetResourceString(SR.ID0522), result.Failures!, StringComparer.Ordinal);
     }
 
     [Fact]
@@ -321,7 +321,7 @@ public class OpenIddictClientConfigurationTests
         var result = configuration.Validate(name: null, options);
 
         // Assert
-        Assert.Contains(SR.GetResourceString(SR.ID0313), result.Failures!);
+        Assert.Contains(SR.GetResourceString(SR.ID0313), result.Failures!, StringComparer.Ordinal);
     }
 
     [Fact]
@@ -335,7 +335,7 @@ public class OpenIddictClientConfigurationTests
         var result = configuration.Validate(name: null, options);
 
         // Assert
-        Assert.Contains(SR.GetResourceString(SR.ID0076), result.Failures!);
+        Assert.Contains(SR.GetResourceString(SR.ID0076), result.Failures!, StringComparer.Ordinal);
     }
 
     [Fact]
@@ -353,7 +353,7 @@ public class OpenIddictClientConfigurationTests
         var result = configuration.Validate(name: null, options);
 
         // Assert
-        Assert.Contains(SR.GetResourceString(SR.ID0285), result.Failures!);
+        Assert.Contains(SR.GetResourceString(SR.ID0285), result.Failures!, StringComparer.Ordinal);
     }
 
     [Fact]
@@ -368,7 +368,7 @@ public class OpenIddictClientConfigurationTests
         var result = configuration.Validate(name: null, options);
 
         // Assert
-        Assert.Contains(SR.GetResourceString(SR.ID0356), result.Failures!);
+        Assert.Contains(SR.GetResourceString(SR.ID0356), result.Failures!, StringComparer.Ordinal);
     }
 
     [Fact]
@@ -384,8 +384,8 @@ public class OpenIddictClientConfigurationTests
         var result = configuration.Validate(name: null, options);
 
         // Assert
-        Assert.Contains(SR.GetResourceString(SR.ID0357), result.Failures!);
-        Assert.Contains(SR.GetResourceString(SR.ID0358), result.Failures!);
+        Assert.Contains(SR.GetResourceString(SR.ID0357), result.Failures!, StringComparer.Ordinal);
+        Assert.Contains(SR.GetResourceString(SR.ID0358), result.Failures!, StringComparer.Ordinal);
     }
 
     [Fact]
@@ -400,7 +400,7 @@ public class OpenIddictClientConfigurationTests
         var result = configuration.Validate(name: null, options);
 
         // Assert
-        Assert.Contains(SR.FormatID0281(ResponseTypes.Code), result.Failures!);
+        Assert.Contains(SR.FormatID0281(ResponseTypes.Code), result.Failures!, StringComparer.Ordinal);
     }
 
     [Fact]
@@ -451,7 +451,7 @@ public class OpenIddictClientConfigurationTests
         var result = configuration.Validate(name: null, options);
 
         // Assert
-        Assert.Contains(SR.GetResourceString(SR.ID0347), result.Failures!);
+        Assert.Contains(SR.GetResourceString(SR.ID0347), result.Failures!, StringComparer.Ordinal);
     }
 
     private static OpenIddictClientOptions CreateBaseOptions()