diff --git a/modules/openapi-generator/src/main/resources/csharp/HttpSigningConfiguration.mustache b/modules/openapi-generator/src/main/resources/csharp/HttpSigningConfiguration.mustache
index 913a483a967..4bc8b396e09 100644
--- a/modules/openapi-generator/src/main/resources/csharp/HttpSigningConfiguration.mustache
+++ b/modules/openapi-generator/src/main/resources/csharp/HttpSigningConfiguration.mustache
@@ -373,8 +373,7 @@ namespace {{packageName}}.Client
             else
                 ecdsa.ImportPkcs8PrivateKey(keyBytes, out byteCount);
 
-            var signedBytes = ecdsa.SignHash(dataToSign);
-            var derBytes = ConvertToECDSAANS1Format(signedBytes);
+            var derBytes = ecdsa.SignHash(dataToSign, DSASignatureFormat.Rfc3279DerSequence);
             var signedString = System.Convert.ToBase64String(derBytes);
 
             return signedString;
@@ -384,6 +383,11 @@ namespace {{packageName}}.Client
             {{/net60OrLater}}
         }
 
+        /// <summary>
+        /// Convert ANS1 format to DER format. Not recommended to use because it generate inavlid signature occationally.
+        /// </summary>
+        /// <param name="signedBytes"></param>
+        /// <returns></returns>
         private byte[] ConvertToECDSAANS1Format(byte[] signedBytes)
         {
             var derBytes = new List<byte>();
diff --git a/samples/client/petstore/csharp/OpenAPIClient-ConditionalSerialization/src/Org.OpenAPITools/Client/HttpSigningConfiguration.cs b/samples/client/petstore/csharp/OpenAPIClient-ConditionalSerialization/src/Org.OpenAPITools/Client/HttpSigningConfiguration.cs
index 329284ff41d..7c8668488ee 100644
--- a/samples/client/petstore/csharp/OpenAPIClient-ConditionalSerialization/src/Org.OpenAPITools/Client/HttpSigningConfiguration.cs
+++ b/samples/client/petstore/csharp/OpenAPIClient-ConditionalSerialization/src/Org.OpenAPITools/Client/HttpSigningConfiguration.cs
@@ -352,6 +352,11 @@ namespace Org.OpenAPITools.Client
             throw new Exception("ECDSA signing is supported only on NETCOREAPP3_0 and above");
         }
 
+        /// <summary>
+        /// Convert ANS1 format to DER format. Not recommended to use because it generate inavlid signature occationally.
+        /// </summary>
+        /// <param name="signedBytes"></param>
+        /// <returns></returns>
         private byte[] ConvertToECDSAANS1Format(byte[] signedBytes)
         {
             var derBytes = new List<byte>();
diff --git a/samples/client/petstore/csharp/OpenAPIClient-httpclient/src/Org.OpenAPITools/Client/HttpSigningConfiguration.cs b/samples/client/petstore/csharp/OpenAPIClient-httpclient/src/Org.OpenAPITools/Client/HttpSigningConfiguration.cs
index 329284ff41d..7c8668488ee 100644
--- a/samples/client/petstore/csharp/OpenAPIClient-httpclient/src/Org.OpenAPITools/Client/HttpSigningConfiguration.cs
+++ b/samples/client/petstore/csharp/OpenAPIClient-httpclient/src/Org.OpenAPITools/Client/HttpSigningConfiguration.cs
@@ -352,6 +352,11 @@ namespace Org.OpenAPITools.Client
             throw new Exception("ECDSA signing is supported only on NETCOREAPP3_0 and above");
         }
 
+        /// <summary>
+        /// Convert ANS1 format to DER format. Not recommended to use because it generate inavlid signature occationally.
+        /// </summary>
+        /// <param name="signedBytes"></param>
+        /// <returns></returns>
         private byte[] ConvertToECDSAANS1Format(byte[] signedBytes)
         {
             var derBytes = new List<byte>();
diff --git a/samples/client/petstore/csharp/OpenAPIClient-net47/src/Org.OpenAPITools/Client/HttpSigningConfiguration.cs b/samples/client/petstore/csharp/OpenAPIClient-net47/src/Org.OpenAPITools/Client/HttpSigningConfiguration.cs
index 329284ff41d..7c8668488ee 100644
--- a/samples/client/petstore/csharp/OpenAPIClient-net47/src/Org.OpenAPITools/Client/HttpSigningConfiguration.cs
+++ b/samples/client/petstore/csharp/OpenAPIClient-net47/src/Org.OpenAPITools/Client/HttpSigningConfiguration.cs
@@ -352,6 +352,11 @@ namespace Org.OpenAPITools.Client
             throw new Exception("ECDSA signing is supported only on NETCOREAPP3_0 and above");
         }
 
+        /// <summary>
+        /// Convert ANS1 format to DER format. Not recommended to use because it generate inavlid signature occationally.
+        /// </summary>
+        /// <param name="signedBytes"></param>
+        /// <returns></returns>
         private byte[] ConvertToECDSAANS1Format(byte[] signedBytes)
         {
             var derBytes = new List<byte>();
diff --git a/samples/client/petstore/csharp/OpenAPIClient-net48/src/Org.OpenAPITools/Client/HttpSigningConfiguration.cs b/samples/client/petstore/csharp/OpenAPIClient-net48/src/Org.OpenAPITools/Client/HttpSigningConfiguration.cs
index 329284ff41d..7c8668488ee 100644
--- a/samples/client/petstore/csharp/OpenAPIClient-net48/src/Org.OpenAPITools/Client/HttpSigningConfiguration.cs
+++ b/samples/client/petstore/csharp/OpenAPIClient-net48/src/Org.OpenAPITools/Client/HttpSigningConfiguration.cs
@@ -352,6 +352,11 @@ namespace Org.OpenAPITools.Client
             throw new Exception("ECDSA signing is supported only on NETCOREAPP3_0 and above");
         }
 
+        /// <summary>
+        /// Convert ANS1 format to DER format. Not recommended to use because it generate inavlid signature occationally.
+        /// </summary>
+        /// <param name="signedBytes"></param>
+        /// <returns></returns>
         private byte[] ConvertToECDSAANS1Format(byte[] signedBytes)
         {
             var derBytes = new List<byte>();
diff --git a/samples/client/petstore/csharp/OpenAPIClient-net5.0/src/Org.OpenAPITools/Client/HttpSigningConfiguration.cs b/samples/client/petstore/csharp/OpenAPIClient-net5.0/src/Org.OpenAPITools/Client/HttpSigningConfiguration.cs
index f8c8de85aba..d98d2815297 100644
--- a/samples/client/petstore/csharp/OpenAPIClient-net5.0/src/Org.OpenAPITools/Client/HttpSigningConfiguration.cs
+++ b/samples/client/petstore/csharp/OpenAPIClient-net5.0/src/Org.OpenAPITools/Client/HttpSigningConfiguration.cs
@@ -380,13 +380,17 @@ namespace Org.OpenAPITools.Client
             else
                 ecdsa.ImportPkcs8PrivateKey(keyBytes, out byteCount);
 
-            var signedBytes = ecdsa.SignHash(dataToSign);
-            var derBytes = ConvertToECDSAANS1Format(signedBytes);
+            var derBytes = ecdsa.SignHash(dataToSign, DSASignatureFormat.Rfc3279DerSequence);
             var signedString = System.Convert.ToBase64String(derBytes);
 
             return signedString;
         }
 
+        /// <summary>
+        /// Convert ANS1 format to DER format. Not recommended to use because it generate inavlid signature occationally.
+        /// </summary>
+        /// <param name="signedBytes"></param>
+        /// <returns></returns>
         private byte[] ConvertToECDSAANS1Format(byte[] signedBytes)
         {
             var derBytes = new List<byte>();
diff --git a/samples/client/petstore/csharp/OpenAPIClient-unityWebRequest/src/Org.OpenAPITools/Client/HttpSigningConfiguration.cs b/samples/client/petstore/csharp/OpenAPIClient-unityWebRequest/src/Org.OpenAPITools/Client/HttpSigningConfiguration.cs
index 329284ff41d..7c8668488ee 100644
--- a/samples/client/petstore/csharp/OpenAPIClient-unityWebRequest/src/Org.OpenAPITools/Client/HttpSigningConfiguration.cs
+++ b/samples/client/petstore/csharp/OpenAPIClient-unityWebRequest/src/Org.OpenAPITools/Client/HttpSigningConfiguration.cs
@@ -352,6 +352,11 @@ namespace Org.OpenAPITools.Client
             throw new Exception("ECDSA signing is supported only on NETCOREAPP3_0 and above");
         }
 
+        /// <summary>
+        /// Convert ANS1 format to DER format. Not recommended to use because it generate inavlid signature occationally.
+        /// </summary>
+        /// <param name="signedBytes"></param>
+        /// <returns></returns>
         private byte[] ConvertToECDSAANS1Format(byte[] signedBytes)
         {
             var derBytes = new List<byte>();
diff --git a/samples/client/petstore/csharp/OpenAPIClient/src/Org.OpenAPITools/Client/HttpSigningConfiguration.cs b/samples/client/petstore/csharp/OpenAPIClient/src/Org.OpenAPITools/Client/HttpSigningConfiguration.cs
index 329284ff41d..7c8668488ee 100644
--- a/samples/client/petstore/csharp/OpenAPIClient/src/Org.OpenAPITools/Client/HttpSigningConfiguration.cs
+++ b/samples/client/petstore/csharp/OpenAPIClient/src/Org.OpenAPITools/Client/HttpSigningConfiguration.cs
@@ -352,6 +352,11 @@ namespace Org.OpenAPITools.Client
             throw new Exception("ECDSA signing is supported only on NETCOREAPP3_0 and above");
         }
 
+        /// <summary>
+        /// Convert ANS1 format to DER format. Not recommended to use because it generate inavlid signature occationally.
+        /// </summary>
+        /// <param name="signedBytes"></param>
+        /// <returns></returns>
         private byte[] ConvertToECDSAANS1Format(byte[] signedBytes)
         {
             var derBytes = new List<byte>();
diff --git a/samples/client/petstore/csharp/OpenAPIClientCore/src/Org.OpenAPITools/Client/HttpSigningConfiguration.cs b/samples/client/petstore/csharp/OpenAPIClientCore/src/Org.OpenAPITools/Client/HttpSigningConfiguration.cs
index f8c8de85aba..d98d2815297 100644
--- a/samples/client/petstore/csharp/OpenAPIClientCore/src/Org.OpenAPITools/Client/HttpSigningConfiguration.cs
+++ b/samples/client/petstore/csharp/OpenAPIClientCore/src/Org.OpenAPITools/Client/HttpSigningConfiguration.cs
@@ -380,13 +380,17 @@ namespace Org.OpenAPITools.Client
             else
                 ecdsa.ImportPkcs8PrivateKey(keyBytes, out byteCount);
 
-            var signedBytes = ecdsa.SignHash(dataToSign);
-            var derBytes = ConvertToECDSAANS1Format(signedBytes);
+            var derBytes = ecdsa.SignHash(dataToSign, DSASignatureFormat.Rfc3279DerSequence);
             var signedString = System.Convert.ToBase64String(derBytes);
 
             return signedString;
         }
 
+        /// <summary>
+        /// Convert ANS1 format to DER format. Not recommended to use because it generate inavlid signature occationally.
+        /// </summary>
+        /// <param name="signedBytes"></param>
+        /// <returns></returns>
         private byte[] ConvertToECDSAANS1Format(byte[] signedBytes)
         {
             var derBytes = new List<byte>();