add Google login

Kemkas.Web/Areas/Identity/Pages/Account/ExternalLogin.cshtml.cs

@@ -123,21 +123,43 @@ namespace Kemkas.Web.Areas.Identity.Pages.Account
             {
                 return RedirectToPage("./Lockout");
             }
-            else
-            {
-                // If the user does not have an account, then ask the user to create an account.
+
+            // If the user does not have an account, and no email claim, then ask the user to create an account.
             ReturnUrl = returnUrl;
             ProviderDisplayName = info.ProviderDisplayName;
-                if (info.Principal.HasClaim(c => c.Type == ClaimTypes.Email))
+            if (!info.Principal.HasClaim(c => c.Type == ClaimTypes.Email))
             {
+                return Page();
+            }
+                
+            // User doesn't have account but external provider has email claim. => Register with claimed email.
             Input = new InputModel
             {
                 Email = info.Principal.FindFirstValue(ClaimTypes.Email)
             };
+            var user = CreateUser();
+            await _userStore.SetUserNameAsync(user, Input.Email, CancellationToken.None);
+            await _emailStore.SetEmailAsync(user, Input.Email, CancellationToken.None);
+            var registrationResult = await _userManager.CreateAsync(user);
+            if (registrationResult.Succeeded)
+            {
+                registrationResult = await _userManager.AddLoginAsync(user, info);
+                if (registrationResult.Succeeded)
+                {
+                    _logger.LogInformation("User created an account using {Name} provider.", info.LoginProvider);
+                    var code = await _userManager.GenerateEmailConfirmationTokenAsync(user);
+                    await _userManager.ConfirmEmailAsync(user, code);
+                    await _signInManager.SignInAsync(user, isPersistent: false, info.LoginProvider);
+                    return LocalRedirect(returnUrl);
                 }
+            }
+            foreach (var error in registrationResult.Errors)
+            {
+                ModelState.AddModelError(string.Empty, error.Description);
+            }
+
             return Page();
         }
-        }
 
         public async Task<IActionResult> OnPostConfirmationAsync(string returnUrl = null)
         {

Kemkas.Web/Kemkas.Web.csproj

@@ -17,6 +17,7 @@
     </PropertyGroup>
 
     <ItemGroup>
+        <PackageReference Include="Microsoft.AspNetCore.Authentication.Google" Version="8.0.0" />
         <PackageReference Include="Microsoft.AspNetCore.DataProtection.EntityFrameworkCore" Version="8.0.0" />
         <PackageReference Include="Microsoft.AspNetCore.Diagnostics.EntityFrameworkCore" Version="8.0.0" />
         <PackageReference Include="Microsoft.AspNetCore.Identity.EntityFrameworkCore" Version="8.0.0" />

Kemkas.Web/Program.cs

@@ -33,7 +33,13 @@ builder.Services.AddSingleton<IEmailSender, MailgunEmailSender>();
 builder.Services.AddDefaultIdentity<ApplicationUser>(options => options.SignIn.RequireConfirmedAccount = true)
     .AddEntityFrameworkStores<ApplicationDbContext>();
 
-builder.Services.AddAuthentication();
+builder.Services.AddAuthentication()
+    .AddGoogle(options =>
+    {
+        var googleAuthNSection = builder.Configuration.GetSection("Authentication:Google");
+        options.ClientId = googleAuthNSection["ClientId"];
+        options.ClientSecret = googleAuthNSection["ClientSecret"];
+    });
 
 builder.Services.AddControllersWithViews().AddJsonOptions(options =>
 {

Kemkas.Web/nginx.conf

@@ -70,7 +70,13 @@ http {
             proxy_set_header X-Forwarded-Proto "$scheme";
             proxy_set_header X-Forwarded-Host "$http_host";
             proxy_pass   https://backend;
+        }
+        location /signin-google/ {
             proxy_pass_request_headers on;
+            proxy_set_header X-Forwarded-For "$proxy_add_x_forwarded_for";
+            proxy_set_header X-Forwarded-Proto "$scheme";
+            proxy_set_header X-Forwarded-Host "$http_host";
+            proxy_pass   https://backend;
         }
         
         location /lib/ {

Kemkas.Web/packages.lock.json

@@ -2,6 +2,12 @@
   "version": 1,
   "dependencies": {
     "net8.0": {
+      "Microsoft.AspNetCore.Authentication.Google": {
+        "type": "Direct",
+        "requested": "[8.0.0, )",
+        "resolved": "8.0.0",
+        "contentHash": "dPE/IiHhBqnJ7WrD72T20+DcHGCaR9F4RmIFap83W1Ts/ze5gBVe4Ii02qJdJzkUniQy5S/v42zpRIgJTPzPqQ=="
+      },
       "Microsoft.AspNetCore.DataProtection.EntityFrameworkCore": {
         "type": "Direct",
         "requested": "[8.0.0, )",