@Override
public Signal.SignatureData callHSM(byte[] dataToSign, HSMPass move) {
// Create the SignRequest for AWS KMS
var signRequest =
SignRequest.builder()
.keyId(keyID)
.message(SdkBytes.fromByteArray(dataHash))
.messageType(MessageType.DIGEST)
.signingAlgorithm(SigningAlgorithmSpec.ECDSA_SHA_256)
.construct();
// Signal the info utilizing AWS KMS
var signResult = kmsClient.signal(signRequest);
var signatureBuffer = signResult.signature().asByteBuffer();
// Convert the signature to byte array
var signBytes = new byte[signatureBuffer.remaining()];
signatureBuffer.get(signBytes);
// Confirm signature osn KMS
var verifyRequest =
VerifyRequest.builder()
.keyId(keyID)
.message(SdkBytes.fromByteArray(dataHash))
.messageType(MessageType.DIGEST)
.signingAlgorithm(SigningAlgorithmSpec.ECDSA_SHA_256)
.signature(SdkBytes.fromByteArray(signBytes))
.construct();
var verifyRequestResult = kmsClient.confirm(verifyRequest);
if (!verifyRequestResult.signatureValid()) {
throw new RuntimeException(“KMS signature is just not legitimate!”);
}
var signature = CryptoUtils.fromDerFormat(signBytes);
return Signal.createSignatureData(signature, move.getPublicKey(), dataHash);
}
NOTE!
So as to use this correctly, the kind of key spec created in AWS KMS have to be ECC_SECG_P256K1. That is particular to the crypto house, particularly to EVM. Utilizing every other key will lead to a mismatch error when the information signature is created.
Instance
Here’s a brief instance of easy methods to name the callHSM methodology from the library:
public static void fundamental(String[] args) throws Exception {
KmsClient consumer = KmsClient.create();
// extract the KMS key
byte[] derPublicKey = consumer
.getPublicKey((var builder) -> {
builder.keyId(kmsKeyId);
})
.publicKey()
.asByteArray();
byte[] rawPublicKey = SubjectPublicKeyInfo
.getInstance(derPublicKey)
.getPublicKeyData()
.getBytes();
BigInteger publicKey = new BigInteger(1, Arrays.copyOfRange(rawPublicKey, 1, rawPublicKey.size));
HSMPass move = new HSMPass(null, publicKey);
HSMRequestProcessor signer = new HSMAwsKMSRequestProcessor(consumer, kmsKeyId);
signer.callHSM(information, move);
}
Conclusion
AWS KMS, with its built-in HSM performance, gives a robust answer for securely managing and signing cryptographic transactions. Regardless of preliminary challenges confronted by customers in integrating AWS KMS with Hyperledger Web3j, the introduction of the HSMAwsKMSRequestProcessor class has made it simpler to undertake and implement. This ready-to-use answer simplifies interactions with AWS KMS, permitting customers to securely signal information and transactions with minimal configuration. By leveraging this device, organizations can improve their safety posture whereas benefiting from the comfort of AWS’s cloud-native HSM capabilities.