Minor refactoring

Author: andrei-m-code

CorePush/Firebase/FirebaseSender.cs

@@ -9,6 +9,7 @@
 using CorePush.Models;
 using CorePush.Serialization;
 using CorePush.Utils;
+
 using Org.BouncyCastle.Crypto.Signers;
 using Org.BouncyCastle.Crypto;
 using Org.BouncyCastle.OpenSsl;
@@ -164,36 +165,30 @@ private string GetMasterToken()
         var unsignedJwtData = $"{headerBase64}.{payloadBase64}";
         var unsignedJwtBytes = Encoding.UTF8.GetBytes(unsignedJwtData);
 
-        var privateKey = ParsePKCS8PrivateKeyPem(settings.PrivateKey);
-        ISigner signer = new RsaDigestSigner(new Org.BouncyCastle.Crypto.Digests.Sha256Digest());
+        var privateKey = ParsePkcs8PrivateKeyPem(settings.PrivateKey);
+        var signer = new RsaDigestSigner(new Org.BouncyCastle.Crypto.Digests.Sha256Digest());
         signer.Init(true, privateKey);
         signer.BlockUpdate(unsignedJwtBytes, 0, unsignedJwtBytes.Length);
 
-        byte[] signature = signer.GenerateSignature();
+        var signature = signer.GenerateSignature();
         var signatureBase64 = Convert.ToBase64String(signature);
 
         return $"{unsignedJwtData}.{signatureBase64}";
     }
 
-    private AsymmetricKeyParameter ParsePKCS8PrivateKeyPem(string key)
+    private static AsymmetricKeyParameter ParsePkcs8PrivateKeyPem(string key)
     {
-        AsymmetricKeyParameter privateKey;
         using var keyReader = new StringReader(key);
-        PemReader pemReader = new PemReader(keyReader);
-        object pemObject = pemReader.ReadObject();
+        var pemReader = new PemReader(keyReader);
+        var pemObject = pemReader.ReadObject();
 
-        // PKCS#8 keys are typically returned as AsymmetricKeyParameter, not AsymmetricCipherKeyPair
-        if (pemObject is AsymmetricKeyParameter keyParameter)
-        {
-            return privateKey = keyParameter;
-        }
-        else if (pemObject is AsymmetricCipherKeyPair keyPair) // handle case of key pair
+        return pemObject switch
         {
-            return privateKey = keyPair.Private;
-        }
-        else
-        {
-            throw new InvalidOperationException("Invalid private key format.");
-        }
+            // PKCS#8 keys are typically returned as AsymmetricKeyParameter, not AsymmetricCipherKeyPair
+            AsymmetricKeyParameter keyParameter => keyParameter,
+            // handle case of key pair
+            AsymmetricCipherKeyPair keyPair => keyPair.Private,
+            _ => throw new InvalidOperationException("Invalid private key format.")
+        };
     }
 }