Ed25519Signer.NET 33.0.0.1

Sign (or verify) data using Ed25519 from RFC8032

Load Key from PEM File

Ed25519KeyDataReader privateKeyData = new Ed25519KeyDataReader("C:\\Keys\\private.pem");

Ed25519PrivateKey privatekey = Ed25519KeyFactory.CreatePrivateKey(privateKeyData.Read());

Load Key from Text File

Ed25519KeyDataReader privateKeyData = new Ed25519KeyDataReader("..\\..\\private3.txt", true);

Ed25519PrivateKey privatekey = Ed25519KeyFactory.CreatePrivateKey(privateKeyData.ReadFromTextFast());            

Load Key from .ED25519 File

Ed25519FileReader privateKeyData = new Ed25519FileReader("..\\..\\private.ED25519");

Ed25519PrivateKey privatekey = Ed25519KeyFactory.CreatePrivateKey(privateKeyData.ReadEd25519Fast());

Signing Data

Ed25519Signer signer = new Ed25519Signer();

signer.Init(privatekey);

signer.BlockUpdate(new byte[32] /* data to sign */, 0 /* offset */, 32 /* data length*/);

byte[] output = signer.GenerateSignature();

signer.Reset();

Verifying Data

Ed25519Verifier verify = new Ed25519Verifier();

verify.Init(publicKey);

verify.BlockUpdate(new byte[32] /* same data to verify */, 0 /* offset */, 32 /* data length*/);

bool v = verify.VerifySignature(output);

verify.Reset();

Creating .ED25519 Files

new Ed25519KeyDataWriter("..\\..\\private.pem", "..\\..\\private.ED25519", true);

Generate Keys

This library can not generate private keys, it just signs data and verifies data.

If you have Windows 10/11 you can generate keys from the command prompt with a standard Windows installation.

// Generate Private Key
openssl genpkey -algorithm ed25519 -out private.pem

// Generate Public Key from the Private Key
openssl pkey -in private.pem -pubout -out public.pem

This also ensures that your keys are really valid and that the library can really understand them.

Full Example

static void Main()
{
    // Signing is usually done by a client
    Ed25519Signer signer = new Ed25519Signer();

    Ed25519KeyDataReader privateKeyData = new Ed25519KeyDataReader("C:\\Keys\\private.pem");

    Ed25519PrivateKey privatekey = Ed25519KeyFactory.CreatePrivateKey(privateKeyData.Read());

    signer.Init(privatekey);

    signer.BlockUpdate(new byte[32] /* data to sign */, 0 /* offset */, 32 /* data length*/);

    byte[] output = signer.GenerateSignature();

    signer.Reset();

    // Verifying is usually done by a server
    Ed25519Verifier verify = new Ed25519Verifier();

    Ed25519KeyDataReader publicKeyData = new Ed25519KeyDataReader("C:\\Keys\\public.pem");

    Ed25519PublicKey publicKey = Ed25519KeyFactory.CreatePublicKey(publicKeyData.Read());

    verify.Init(publicKey);

    verify.BlockUpdate(new byte[32] /* same data to verify */, 0 /* offset */, 32 /* data length*/);

    bool v = verify.VerifySignature(output);

    verify.Reset();

    // Data Matches
    if (v)
    {
        Console.WriteLine("Yes");
    }
    else
    {
        Console.WriteLine("No");
    }

    Console.ReadLine();
}