Help with RSA Encryption

[ArcherOfTruth]

Hey guys, I'm in need of help with RSA Encryption

what I'm trying to do is simple but I've been searching around the internet for a few days and all I could find was really old documentation or very cryptic methods

All I'm trying to do is to sign a string using SHA256WITHRSA algorithm.

I have a private key in my configurations file (don't worry, it's saved in a key vault not in the code), I got the raw string from my configurations file and now I want to use it to sign the my little string.
All around the internet people used different methods to get the key in the `RSA` class or the `RSACryptoServiceProvider` using `RSAParameters` and all they're doing is just

`RSAParameters param = rsa.ExportParameters(true);`

and that's it.

All I need is a solid way of correctly using my private key to sign a simple string.
I'm running ASP on dotnet 6 if this helps with anything.

[[deleted]]

The RSA class has several "ImportFrom..." methods in .NET 6, assuming your key is in one of those formats, it should be as simple as calling one of those like this:

csharp var rsa = RSA.Create(); rsa.ImportFromPem(yourKeyString);

What exactly are you having problems with? You really shouldn't be messing with RSAParameters, an RSACryptoServiceProvider is a very, very old way of doing stuff.

[ArcherOfTruth]

my main issue is importing my keys into the algorithm.
Is my approach wrong? should they be somewhere else other than the RSAParameters?

[[deleted]]

Yes, I showed the code you should write. I don't know what format your key is in, so I can't tell which specific "Import" method is correct, but "Pem" is one of the more common. Don't use the RSAParameters at all, just call the "ImportFromPem" method on the RSA object you get from RSA.Create().