Dart

Ed25519 Sign and Verify

See more Ed25519 Examples

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

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

Dart

import 'package:chilkat/chilkat.dart';

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

  final privKeyHex = '1498b5467a63dffa2dc9d9e069caf075d16fc33fdd4c3b01bfadae6433767d93';
  final pubKeyHex = 'b7a3c12dc0c8c748ab07525b701122b88bd78f600c76342d27f25e5f92444cde';

  final privKey = CkPrivateKey();
  // 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.
  try {
    privKey.loadEd25519(privKeyHex, pubKeyHex);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  // The data to be signed...
  final bd = CkBinData();
  bd.appendString('Message for Ed25519 signing', 'utf-8');

  final eddsa = CkEdDSA();
  final hexSig = eddsa.signBdENC(bd, 'hexlower', privKey);

  print('signature = $hexSig');

  // The expected output is: 6dd355667fae4eb43c6e0ab92e870edb2de0a88cae12dbd8591507f584fe4912babff497f1b8edf9567d2483d54ddc6459bea7855281b7a246a609e3001a4e08

  // Verify the signature..
  final pubKey = CkPublicKey();
  try {
    pubKey.loadEd25519(pubKeyHex);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  try {
    eddsa.verifyBdENC(bd, hexSig, 'hexlower', pubKey);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    print('Failed to verify the signature.');
    return;
  }

  print('The Ed25519 signature is verified!');
}