(Java) 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.

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import com.chilkatsoft.*;

public class ChilkatExample {

  static {
    try {
        System.loadLibrary("chilkat");
    } catch (UnsatisfiedLinkError e) {
      System.err.println("Native code library failed to load.\n" + e);
      System.exit(1);
    }
  }

  public static void main(String argv[])
  {
    // 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";

    CkPrivateKey privKey = new CkPrivateKey();
    boolean success = privKey.LoadEd25519(privKeyHex,pubKeyHex);
    if (success == false) {
        System.out.println(privKey.lastErrorText());
        return;
        }

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

    CkEdDSA eddsa = new CkEdDSA();
    // Indicate we want the Ed25519ph instance.
    eddsa.put_Algorithm("Ed25519ph");

    String hexSig = eddsa.signBdENC(bd,"hexlower",privKey);

    System.out.println("signature = " + hexSig);

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

    // Verify the signature..
    CkPublicKey pubKey = new CkPublicKey();
    success = pubKey.LoadEd25519(pubKeyHex);
    if (success == false) {
        System.out.println(pubKey.lastErrorText());
        return;
        }

    boolean bVerified = eddsa.VerifyBdENC(bd,hexSig,"hexlower",pubKey);
    if (bVerified == false) {
        System.out.println(eddsa.lastErrorText());
        System.out.println("Failed to verify the signature.");
        return;
        }

    System.out.println("The Ed25519ph signature is verified!");
  }
}