Add ArcGIS Online to the list of supported providers

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

@@ -26,6 +26,7 @@ public static partial class OpenIddictClientWebIntegrationHandlers
              */
             AttachRequestHeaders.Descriptor,
             AttachAccessTokenParameter.Descriptor,
+            AttachNonStandardParameters.Descriptor,
 
             /*
              * Userinfo response extraction:
@@ -125,6 +126,41 @@ public static partial class OpenIddictClientWebIntegrationHandlers
             }
         }
 
+        /// <summary>
+        /// Contains the logic responsible for attaching non-standard
+        /// parameters to the request for the providers that require it.
+        /// </summary>
+        public sealed class AttachNonStandardParameters : IOpenIddictClientHandler<PrepareUserinfoRequestContext>
+        {
+            /// <summary>
+            /// Gets the default descriptor definition assigned to this handler.
+            /// </summary>
+            public static OpenIddictClientHandlerDescriptor Descriptor { get; }
+                = OpenIddictClientHandlerDescriptor.CreateBuilder<PrepareUserinfoRequestContext>()
+                    .UseSingletonHandler<AttachNonStandardParameters>()
+                    .SetOrder(AttachQueryStringParameters<PrepareUserinfoRequestContext>.Descriptor.Order - 250)
+                    .SetType(OpenIddictClientHandlerType.BuiltIn)
+                    .Build();
+
+            /// <inheritdoc/>
+            public ValueTask HandleAsync(PrepareUserinfoRequestContext context)
+            {
+                if (context is null)
+                {
+                    throw new ArgumentNullException(nameof(context));
+                }
+
+                // ArcGIS Online doesn't support header-based content negotiation and requires using
+                // the non-standard "f" parameter to get back JSON responses instead of HTML pages.
+                if (context.Registration.ProviderName is Providers.ArcGisOnline)
+                {
+                    context.Request["f"] = "json";
+                }
+
+                return default;
+            }
+        }
+
         /// <summary>
         /// Contains the logic responsible for normalizing the returned content
         /// type of userinfo responses for the providers that require it.

src/OpenIddict.Client.WebIntegration/OpenIddictClientWebIntegrationProviders.xml

@@ -29,6 +29,30 @@
              Description="The optional value used as the 'resource' parameter (e.g urn:microsoft:userinfo)" />
   </Provider>
 
+  <!--
+                              ▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄
+                              █ ▄▄▀██ ▄▄▀██ ▄▄▀██ ▄▄ █▄ ▄██ ▄▄▄ ████ ▄▄▄ ██ ▀██ ██ ████▄ ▄██ ▀██ ██ ▄▄▄██
+                              █ ▀▀ ██ ▀▀▄██ █████ █▀▀██ ███▄▄▄▀▀████ ███ ██ █ █ ██ █████ ███ █ █ ██ ▄▄▄██
+                              █ ██ ██ ██ ██ ▀▀▄██ ▀▀▄█▀ ▀██ ▀▀▀ ████ ▀▀▀ ██ ██▄ ██ ▀▀ █▀ ▀██ ██▄ ██ ▀▀▀██
+                              ▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀
+  -->
+
+  <Provider Name="ArcGisOnline" DisplayName="ArcGIS Online"
+            Documentation="https://developers.arcgis.com/documentation/mapping-apis-and-services/security/oauth-2.0/">
+    <Environment Issuer="https://www.arcgis.com/">
+      <Configuration AuthorizationEndpoint="https://www.arcgis.com/sharing/rest/oauth2/authorize"
+                     TokenEndpoint="https://www.arcgis.com/sharing/rest/oauth2/token"
+                     UserinfoEndpoint="https://www.arcgis.com/sharing/rest/community/self">
+        <CodeChallengeMethod Value="plain" />
+        <CodeChallengeMethod Value="S256" />
+
+        <GrantType Value="authorization_code" />
+        <GrantType Value="client_credentials" />
+        <GrantType Value="refresh_token" />
+      </Configuration>
+    </Environment>
+  </Provider>
+
   <!--
                                                   ▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄
                                                   █ ▄▄▀██ ▄▄ ██ ▄▄ ██ █████ ▄▄▄██