Add tests and fixes to .well-known/openid-configuration and create realm

IdentityShroud.Core/Model/Key.cs

@@ -0,0 +1,45 @@
+using System.ComponentModel.DataAnnotations.Schema;
+using IdentityShroud.Core.Contracts;
+
+namespace IdentityShroud.Core.Model;
+
+
+[Table("key")]
+public class Key
+{
+    private byte[] _privateKeyDecrypted = [];
+
+    public Guid Id { get; set; }
+    
+    public DateTime CreatedAt { get; set; }
+    public DateTime? DeactivatedAt { get; set; }
+
+    /// <summary>
+    /// Key with highest priority will be used. While there is not really a use case for this I know some users
+    /// are more comfortable replacing keys by using priority then directly deactivating the old key.
+    /// </summary>
+    public int Priority { get; set; } = 10;
+    
+    public byte[] PrivateKeyEncrypted
+    {
+        get;
+        set
+        {
+            field = value;
+            _privateKeyDecrypted = [];
+        }
+    } = [];
+
+    public byte[] GetPrivateKey(IEncryptionService encryptionService)
+    {
+        if (_privateKeyDecrypted.Length == 0 && PrivateKeyEncrypted.Length > 0)
+            _privateKeyDecrypted = encryptionService.Decrypt(PrivateKeyEncrypted);
+        return _privateKeyDecrypted;
+    }
+
+    public void SetPrivateKey(IEncryptionService encryptionService, byte[] privateKey)
+    {
+        PrivateKeyEncrypted = encryptionService.Encrypt(privateKey);
+        _privateKeyDecrypted = privateKey;
+    }
+}