Error (active) CS1061 'RSA' does not contain a definition for 'ImportPkcs8PrivateKey' and no accessible extension method 'ImportPkcs8PrivateKey' accepting a first argument of type 'RSA' could be found (are you missing a using directive or an assembly refe

Question

I am using Visual Studio 2022 and have set up a console application.

It tells me that mportPkcs8PrivateKey is not implemented.

This method is indeed implemented with dotnet core 8

https://learn.microsoft.com/en-us/dotnet/api/system.security.cryptography.rsa.importpkcs8privatekey?view=net-8.0

What am I doing wrong? Is there any missing nuget package?

Thanks

using System.Security.Cryptography;

privateKey = privateKey.Replace("-----BEGIN PRIVATE KEY-----", string.Empty).Replace("-----END PRIVATE KEY-----", string.Empty);

privateKey = privateKey.Replace(Environment.NewLine, string.Empty);

// CHANGE CONVERSION TYPE

var privateKeyBytes = Convert.FromBase64String(privateKey);

var rsa = RSA.Create();

rsa.ImportPkcs8PrivateKey(privateKeyBytes, out _);

Severity Code Description Project File Line Suppression State

Error (active) CS1061 'RSA' does not contain a definition for 'ImportPkcs8PrivateKey' and no accessible extension method 'ImportPkcs8PrivateKey' accepting a first argument of type 'RSA' could be found (are you missing a using directive or an assembly reference?) ConsoleApp4 - jwt C:\Users\hp800\source\repos\ConsoleApp4 - jwt\ConsoleApp4 - jwt\Program.cs 67

framework dotnet 4.8.1

core dotnet 8.0.304

Answer 1

C# is strongly typed language. There is no signature of ImportPkcs8PrivateKey() that accepts a byte array, you must convert privateKeyBytes to a ReadOnlySpan<byte>.

Answer 2

Hi @try again , Welcome to Microsoft Q&A,

RSA.ImportPkcs8PrivateKey(ReadOnlySpan<Byte>, Int32) Method only supports Core 3.0, Core 3.1, 5, 6, 7, 8, 9.

In my test, you may have created the wrong platform. In the .Net 8.0 Console project I created, it can be recognized correctly. If it is a .Net Framework 4.8..1 project, the above error will appear. This is caused by the wrong platform.

Best Regards,

Jiale

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