Sign a transaction with Cardano wallet keys.

CardanoWalletSignTest.java

//    implementation group: 'net.java.dev.jna', name: 'jna', version: '5.8.0'
//    implementation group: 'net.java.dev.jna', name: 'jna-platform', version: '5.8.0'

//    implementation group: 'org.bouncycastle', name: 'bcprov-jdk15to18', version: '1.68'

@Test
    public void testThree() throws CborException {
        var skeyCBORHex = "582004927daa27b227b379e0a7c8bc431200dde599e76793931082c37b3ecb8a6031";
        var vkeyCBORHex = "58203b90cdc93baa2a51689e6ae747dcc9ec6e3bf8f11963bcba50036a2443c09b0b";

        var skeyBytesActual = (ByteString) CborDecoder.decode(Hex.decode(skeyCBORHex)).get(0);
        var vkeyBytesActual = (ByteString) CborDecoder.decode(Hex.decode(vkeyCBORHex)).get(0);

        // This can be used as intermediary with cbor.me
        // var skeyHex = "";
        // var vkeyHex = "";
        // var skeyBytes = Hex.decode(skeyHex);
        // var vkeyBytes = Hex.decode(vkeyHex);
        // assertArrayEquals(skeyBytes, skeyBytesActual.getBytes());
        // assertArrayEquals(vkeyBytes, vkeyBytesActual.getBytes());

        var privateKey = new Ed25519PrivateKeyParameters(skeyBytesActual.getBytes(), 0);
        var actualVekey = privateKey.generatePublicKey();
        var publicKey = new Ed25519PublicKeyParameters(vkeyBytesActual.getBytes(), 0);

        assertEquals(
                new String(publicKey.getEncoded()),
                new String(actualVekey.getEncoded())
        );

        var msg = "Cardano is the best blockchain. Sign. Gimbalabs".getBytes(StandardCharsets.UTF_8);

        // Generate new signature
        var signer = new Ed25519Signer();
        signer.init(true, privateKey);
        signer.update(msg, 0, msg.length);
        byte[] signature = signer.generateSignature();

        var verifies = new Ed25519Signer();
        verifies.init(false, publicKey);
        verifies.update(msg, 0, msg.length);
        var outcome = verifies.verifySignature(signature);
        System.out.println(outcome);
        assertTrue(outcome);

        System.out.printf("Message: %s\n", new String(msg));
        System.out.printf("Signature: %s\n", new String(signature));

    }