Is there a Microsoft library for ed25519 signature verification?

Question

I've been going in circles trying to get a simple ed25519 signature verification working. Had success with libsodium third party library but then ran into issues with it and am back to the drawing board. I see system.security.cryptography.ecdsa but it's not clear to me if it's possible to get that to work with a ed25519 signature. I'm kind of surprised there aren't code examples of doing this sig verification in .Net because I thought ed25519 was a reasonably common algorithm?

Is there a Microsoft library for ed25519 signature verification? Or can anyone provide an example of how to successfully do this in .Net?

Nothing in the MS libs for this. However, if you are using .NET then you can try: https://github.com/nitrachain/NitraLibSodium — Brian Webb, Jan 23 '20 at 18:59
ty, but i tried libsodium and it can't run on azure due to dll issues seemingly (https://stackoverflow.com/questions/37347620/libsodium-net-unable-to-load-dll-libsodium-dll/37526795 the vs 2015 redistributable isn't available). every alternative i've found seems to be a wrapper for libsodium which i'd imagine would have the same problem unfortunately — Joe Tonka, Jan 23 '20 at 19:48

score 2 · Answer 1 · edited Oct 07 '22 at 22:03

You can use BouncyCastle for this purpose. Below is the code example of how I am doing it. For using this code make sure the publicKey and signature are hex strings.

public Task<bool> VerifySignature(string publicKey, string dataToVerify, string signature)
{
    var publicKeyParam = new Ed25519PublicKeyParameters(Hex.DecodeStrict(publicKey));
    var dataToVerifyBytes = Encoding.UTF8.GetBytes(dataToVerify);
    var signatureBytes = Convert.FromHexString(signature);

    var verifier = new Ed25519Signer();
    verifier.Init(false, publicKeyParam);
    verifier.BlockUpdate(dataToVerifyBytes, 0, dataToVerifyBytes.Length);
    var isVerified = verifier.VerifySignature(signatureBytes);
    return Task.FromResult(isVerified);
}

Is there a Microsoft library for ed25519 signature verification?

1 Answers1