Replace the email with the username before using the Identity methods.

modules/account/src/Volo.Abp.Account.Web/Areas/Account/Controllers/AccountController.cs

@@ -6,6 +6,7 @@ using Microsoft.AspNetCore.Mvc;
 using Volo.Abp.Account.Web.Areas.Account.Controllers.Models;
 using Volo.Abp.AspNetCore.Mvc;
 using Volo.Abp.Identity;
+using Volo.Abp.Validation;
 using SignInResult = Microsoft.AspNetCore.Identity.SignInResult;
 using UserLoginInfo = Volo.Abp.Account.Web.Areas.Account.Controllers.Models.UserLoginInfo;
 
@@ -33,6 +34,8 @@ namespace Volo.Abp.Account.Web.Areas.Account.Controllers
         {
             ValidateLoginInfo(login);
 
+            await ReplaceEmailToUsernameOfInputIfNeeds(login);
+
             return GetAbpLoginResult(await _signInManager.PasswordSignInAsync(
                 login.UserNameOrEmailAddress,
                 login.Password,
@@ -56,6 +59,28 @@ namespace Volo.Abp.Account.Web.Areas.Account.Controllers
             return GetAbpLoginResult(await _signInManager.CheckPasswordSignInAsync(identityUser, login.Password, true));
         }
 
+        protected virtual async Task ReplaceEmailToUsernameOfInputIfNeeds(UserLoginInfo login)
+        {
+            if (!ValidationHandler.IsValidEmailAddress(login.UserNameOrEmailAddress))
+            {
+                return;
+            }
+
+            var userByUsername = await _userManager.FindByNameAsync(login.UserNameOrEmailAddress);
+            if (userByUsername != null)
+            {
+                return;
+            }
+
+            var userByEmail = await _userManager.FindByEmailAsync(login.UserNameOrEmailAddress);
+            if (userByEmail == null)
+            {
+                return;
+            }
+
+            login.UserNameOrEmailAddress = userByEmail.UserName;
+        }
+
         private static AbpLoginResult GetAbpLoginResult(SignInResult result)
         {
             if (result.IsLockedOut)

modules/identityserver/src/Volo.Abp.IdentityServer.Domain/Volo.Abp.IdentityServer.Domain.csproj

@@ -19,6 +19,7 @@
     <ProjectReference Include="..\..\..\..\framework\src\Volo.Abp.AutoMapper\Volo.Abp.AutoMapper.csproj" />
     <ProjectReference Include="..\..\..\..\framework\src\Volo.Abp.Security\Volo.Abp.Security.csproj" />
     <ProjectReference Include="..\..\..\..\framework\src\Volo.Abp.Caching\Volo.Abp.Caching.csproj" />
+    <ProjectReference Include="..\..\..\..\framework\src\Volo.Abp.Validation\Volo.Abp.Validation.csproj" />
   </ItemGroup>
 
   <ItemGroup>

modules/identityserver/src/Volo.Abp.IdentityServer.Domain/Volo/Abp/IdentityServer/AbpIdentityServerDomainModule.cs

@@ -7,6 +7,7 @@ using Volo.Abp.Identity;
 using Volo.Abp.IdentityServer.Clients;
 using Volo.Abp.Modularity;
 using Volo.Abp.Security;
+using Volo.Abp.Validation;
 
 namespace Volo.Abp.IdentityServer
 {
@@ -15,7 +16,8 @@ namespace Volo.Abp.IdentityServer
         typeof(AbpAutoMapperModule),
         typeof(AbpIdentityDomainModule),
         typeof(AbpSecurityModule),
-        typeof(AbpCachingModule)
+        typeof(AbpCachingModule),
+        typeof(AbpValidationModule)
         )]
     public class AbpIdentityServerDomainModule : AbpModule
     {

modules/identityserver/src/Volo.Abp.IdentityServer.Domain/Volo/Abp/IdentityServer/AspNetIdentity/AbpResourceOwnerPasswordValidator.cs

@@ -12,6 +12,7 @@ using Microsoft.Extensions.Logging;
 using Volo.Abp.Identity;
 using Volo.Abp.Security.Claims;
 using Volo.Abp.Uow;
+using Volo.Abp.Validation;
 
 namespace Volo.Abp.IdentityServer.AspNetIdentity
 {
@@ -42,6 +43,8 @@ namespace Volo.Abp.IdentityServer.AspNetIdentity
         [UnitOfWork]
         public virtual async Task ValidateAsync(ResourceOwnerPasswordValidationContext context)
         {
+            await ReplaceEmailToUsernameOfInputIfNeeds(context);
+
             var user = await _userManager.FindByNameAsync(context.UserName);
             if (user != null)
             {
@@ -90,6 +93,28 @@ namespace Volo.Abp.IdentityServer.AspNetIdentity
             context.Result = new GrantValidationResult(TokenRequestErrors.InvalidGrant);
         }
 
+        protected virtual async Task ReplaceEmailToUsernameOfInputIfNeeds(ResourceOwnerPasswordValidationContext context)
+        {
+            if (!ValidationHandler.IsValidEmailAddress(context.UserName))
+            {
+                return;
+            }
+
+            var userByUsername = await _userManager.FindByNameAsync(context.UserName);
+            if (userByUsername != null)
+            {
+                return;
+            }
+
+            var userByEmail = await _userManager.FindByEmailAsync(context.UserName);
+            if (userByEmail == null)
+            {
+                return;
+            }
+
+            context.UserName = userByEmail.UserName;
+        }
+
         protected virtual Task AddCustomClaimsAsync(List<Claim> customClaims, IdentityUser user, ResourceOwnerPasswordValidationContext context)
         {
             if (user.TenantId.HasValue)