refactor: Validierung für Pem-Eigenschaft hinzugefügt, um Ausnahme bei Nicht-Initialisierung auszulösen

- Die Pem-Eigenschaft wurde aktualisiert, um eine Validierung hinzuzufügen, die eine InvalidOperationException auslöst, falls sie vor der Initialisierung aufgerufen wird.
 - Nicht verwendeten Import System.Text.Json.Serialization entfernt.
 - Fehlermeldungen wurden erweitert, um Issuer und Audience für eine bessere Debugging-Kontextbereitschaft einzuschließen.

DigitalData.Core.Abstractions/Security/IRSACryptographer.cs

@@ -1,5 +1,4 @@
 using System.Security.Cryptography;
-using System.Text.Json.Serialization;
 
 namespace DigitalData.Core.Abstractions.Security
 {
@@ -12,7 +11,5 @@ namespace DigitalData.Core.Abstractions.Security
         public string Issuer { get; init; }
 
         public string Audience { get; init; }
-
-        public void Init();
     }
 }

DigitalData.Core.Security/Cryptographer/RSACryptographer.cs

@@ -1,6 +1,5 @@
 using DigitalData.Core.Abstractions.Security;
 using System.Security.Cryptography;
-using System.Text.Json.Serialization;
 
 namespace DigitalData.Core.Security.Cryptographer
 {
@@ -8,7 +7,12 @@ namespace DigitalData.Core.Security.Cryptographer
     {
         private string? _pem;
 
-        public virtual string Pem { get => _pem; init => _pem = value; }
+        public string Pem
+        {
+            get => _pem
+                ?? throw new InvalidOperationException($"Pem is not initialized. Please ensure that the PEM is set or properly loaded from the file. Issuer: {Issuer}, Audience: {Audience}.");
+            init => _pem = value;
+        }
 
         public string? PemPath => FileName is null ? null : Path.Combine(Directory, FileName);
 

DigitalData.Core.Security/Cryptographer/RSADecryptor.cs

@@ -27,10 +27,6 @@ namespace DigitalData.Core.Security.Cryptographer
 
         public IRSAEncryptor Encryptor => _lazyEncryptor.Value;
 
-        private readonly Lazy<RSA> lazyRSA;
-
-        protected override RSA RSA => lazyRSA.Value;
-
         public RSADecryptor()
         {
             _lazyEncryptor = new(() => new RSAEncryptor()
@@ -38,21 +34,19 @@ namespace DigitalData.Core.Security.Cryptographer
                 Pem = RSA.ExportRSAPublicKeyPem(),
                 Padding = Padding
             });
-
-            lazyRSA = new(() =>
-            {
-                var rsa = RSA.Create();
-                if (_password is null)
-                    RSA.ImportFromPem(Pem);
-                else
-                    RSA.ImportFromEncryptedPem(Pem, _password.AsSpan());
-
-                return rsa;
-            });
         }
 
         public byte[] Decrypt(byte[] data) => RSA.Decrypt(data, Padding);
 
         public string Decrypt(string data) => RSA.Decrypt(data.Base64ToByte(), Padding).BytesToString();
+
+        public override void Init()
+        {
+            base.Init();
+            if (_password is null)
+                RSA.ImportFromPem(Pem);
+            else
+                RSA.ImportFromEncryptedPem(Pem, _password.AsSpan());
+        }
     }
 }

DigitalData.Core.Security/Cryptographer/RSAEncryptor.cs

@@ -4,21 +4,17 @@ using DigitalData.Core.Security.Extensions;
 namespace DigitalData.Core.Security.Cryptographer
 {
     public class RSAEncryptor : RSACryptographer, IRSAEncryptor, IRSACryptographer
-    {
-        public override string Pem
-        {
-            get => base.Pem;
-            init
-            {
-                RSA.ImportFromPem(base.Pem);
-                base.Pem = value;
-            }
-        }
-        
+    {   
         public byte[] Encrypt(byte[] data) => RSA.Encrypt(data, Padding);
 
         public string Encrypt(string data) => RSA.Encrypt(data.Base64ToByte(), Padding).BytesToString();
 
         public bool Verify(string data, string signature) => Encrypt(data) == signature;
+
+        public override void Init()
+        {
+            base.Init();
+            RSA.ImportFromPem(base.Pem);
+        }
     }
 }