(C# UWP/WinRT) Ed25519 Sign and Verify

Demonstrates how to create an Ed25519 signature, and then to verify it.

Note: This example requires Chilkat v9.5.0.83 or greater.

Chilkat Universal Windows Platform (UWP) / WinRT Downloads Chilkat for the Universal Windows Platform (UWP)

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

string privKeyHex = "1498b5467a63dffa2dc9d9e069caf075d16fc33fdd4c3b01bfadae6433767d93";
string pubKeyHex = "b7a3c12dc0c8c748ab07525b701122b88bd78f600c76342d27f25e5f92444cde";

Chilkat.PrivateKey privKey = new Chilkat.PrivateKey();
// This example shows only one way of loading an Ed25519 private key.
// Chilkat can load other formats (JWK, PEM, ASN.1 DER, etc.)  
// You may do so by calling LoadAnyFormat or LoadAnyFormatFile.
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.AppendString("Message for Ed25519 signing","utf-8");

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

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

// The expected output is: 6dd355667fae4eb43c6e0ab92e870edb2de0a88cae12dbd8591507f584fe4912babff497f1b8edf9567d2483d54ddc6459bea7855281b7a246a609e3001a4e08

// 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 Ed25519 signature is verified!");