(.NET Core C#) Ed25519ph Sign and Verify

Demonstrates how to create an Ed25519ph signature, and then to verify it.

Note: This example requires Chilkat v9.5.0.91 or greater.

Chilkat .NET Downloads Chilkat .NET Assemblies Chilkat for .NET Core Chilkat for Mono

// This example assumes the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

// Use the following test vector from https://www.rfc-editor.org/rfc/rfc8032#page-30

//    -----TEST abc
// 
//    ALGORITHM:
//    Ed25519ph
// 
//    SECRET KEY:
//    833fe62409237b9d62ec77587520911e
//    9a759cec1d19755b7da901b96dca3d42
// 
//    PUBLIC KEY:
//    ec172b93ad5e563bf4932c70e1245034
//    c35467ef2efd4d64ebf819683467e2bf
// 
//    MESSAGE (length 3 bytes):
//    616263
// 
//    SIGNATURE:
//    98a70222f0b8121aa9d30f813d683f80
//    9e462b469c7ff87639499bb94e6dae41
//    31f85042463c2a355a2003d062adf5aa
//    a10b8c61e636062aaad11c2a26083406

string privKeyHex = "833fe62409237b9d62ec77587520911e9a759cec1d19755b7da901b96dca3d42";
string pubKeyHex = "ec172b93ad5e563bf4932c70e1245034c35467ef2efd4d64ebf819683467e2bf";

Chilkat.PrivateKey privKey = new Chilkat.PrivateKey();
bool success = privKey.LoadEd25519(privKeyHex,pubKeyHex);
if (success == false) {
    Debug.WriteLine(privKey.LastErrorText);
    return;
}

// The data to be signed...
Chilkat.BinData bd = new Chilkat.BinData();
bd.AppendEncoded("616263","hex");

Chilkat.EdDSA eddsa = new Chilkat.EdDSA();
// Indicate we want the Ed25519ph instance.
eddsa.Algorithm = "Ed25519ph";

string hexSig = eddsa.SignBdENC(bd,"hexlower",privKey);

Debug.WriteLine("signature = " + hexSig);

// The expected output is: 98a70222f0b8121aa9d30f813d683f80....

// Verify the signature..
Chilkat.PublicKey pubKey = new Chilkat.PublicKey();
success = pubKey.LoadEd25519(pubKeyHex);
if (success == false) {
    Debug.WriteLine(pubKey.LastErrorText);
    return;
}

bool bVerified = eddsa.VerifyBdENC(bd,hexSig,"hexlower",pubKey);
if (bVerified == false) {
    Debug.WriteLine(eddsa.LastErrorText);
    Debug.WriteLine("Failed to verify the signature.");
    return;
}

Debug.WriteLine("The Ed25519ph signature is verified!");