OpenID Connect support (#3975)

Co-authored-by: DieselTech <30128380+DieselTech@users.noreply.github.com>
Co-authored-by: majora2007 <josephmajora@gmail.com>

API/Extensions/ClaimsPrincipalExtensions.cs

@@ -1,4 +1,7 @@
-using System.Security.Claims;
+using System.Collections.Generic;
+using System.Linq;
+using System.Security.Claims;
+using API.Constants;
 using Kavita.Common;
 using JwtRegisteredClaimNames = Microsoft.IdentityModel.JsonWebTokens.JwtRegisteredClaimNames;
 
@@ -8,6 +11,8 @@ namespace API.Extensions;
 public static class ClaimsPrincipalExtensions
 {
     private const string NotAuthenticatedMessage = "User is not authenticated";
+    private const string EmailVerifiedClaimType = "email_verified";
+
     /// <summary>
     /// Get's the authenticated user's username
     /// </summary>
@@ -26,4 +31,26 @@ public static class ClaimsPrincipalExtensions
         var userClaim = user.FindFirst(ClaimTypes.NameIdentifier) ?? throw new KavitaException(NotAuthenticatedMessage);
         return int.Parse(userClaim.Value);
     }
+
+    public static bool HasVerifiedEmail(this ClaimsPrincipal user)
+    {
+        var emailVerified = user.FindFirst(EmailVerifiedClaimType);
+        if (emailVerified == null) return false;
+
+        if (!bool.TryParse(emailVerified.Value, out bool emailVerifiedValue) || !emailVerifiedValue)
+        {
+            return false;
+        }
+
+        return true;
+    }
+
+    public static IList<string> GetClaimsWithPrefix(this ClaimsPrincipal claimsPrincipal, string claimType, string prefix)
+    {
+        return claimsPrincipal
+            .FindAll(claimType)
+            .Where(c => c.Value.StartsWith(prefix))
+            .Select(c => c.Value.TrimPrefix(prefix))
+            .ToList();
+    }
 }