/// <inheritdoc />
protected override Task <JObject> SignAsync(IVerifyData verifyData, JObject proof, ProofOptions options)
{
var verifyDataArray = verifyData as StringArray ?? throw new Exception("Unsupported verify data type");
var derivedProof = new JObject {
{ "@context", Constants.SECURITY_CONTEXT_V3_URL }
};
var originalProof = options.AdditonalData["originalDocument"]["proof"];
var signature = Convert.FromBase64String(originalProof["proofValue"].ToString());
var keyPair = new Bls12381G2Key2020(GetVerificationMethod(originalProof as JObject, options));
var bbsKey = keyPair.ToBlsKeyPair().GetBbsKey((uint)verifyDataArray.Data.Length);
var nonce = Nonce ?? Encoding.UTF8.GetBytes(Guid.NewGuid().ToString());
var proofMessages = GetProofMessages(
allInputStatements: verifyDataArray.Data,
revealIndicies: options.AdditonalData["revealIndicies"].ToObject <int[]>());
var outputProof = Service.CreateProof(new CreateProofRequest(
publicKey: bbsKey,
messages: proofMessages.ToArray(),
signature: signature,
blindingFactor: null,
nonce: nonce));
// Set the proof value on the derived proof
derivedProof["proofValue"] = Convert.ToBase64String(outputProof);
derivedProof["nonce"] = Convert.ToBase64String(nonce);
derivedProof["created"] = originalProof["created"];
derivedProof["proofPurpose"] = originalProof["proofPurpose"];
derivedProof["verificationMethod"] = originalProof["verificationMethod"];
derivedProof["type"] = "BbsBlsSignatureProof2020";
return(Task.FromResult(derivedProof));
}
protected override Task VerifyAsync(IVerifyData payload, JToken proof, JToken verificationMethod, ProofOptions options)
{
var verifyData = payload as StringArray ?? throw new ArgumentException("Invalid data type");
var blsVerificationMethod = new Bls12381G2Key2020(verificationMethod as JObject);
var key = new BlsKeyPair(Multibase.Base58.Decode(blsVerificationMethod.PublicKeyBase58));
var signature = Helpers.FromBase64String(proof["proofValue"]?.ToString() ?? throw new Exception("Proof value not found"));
var valid = SignatureService.Verify(new VerifyRequest(key, signature, verifyData.Data));
if (!valid)
{
throw new Exception("Invalid signature");
}
return(Task.CompletedTask);
}
/// <inheritdoc />
protected override Task VerifyAsync(IVerifyData verifyData, JToken proof, JToken verificationMethod, ProofOptions options)
{
var stringArray = verifyData as StringArray ?? throw new Exception("Unsupported verify data type");
var proofData = Helpers.FromBase64String(proof["proofValue"]?.ToString() ?? throw new Exception("Proof value not found"));
var nonce = Helpers.FromBase64String(proof["nonce"]?.ToString() ?? throw new Exception("Nonce not found"));
var keyPair = new Bls12381G2Key2020(GetVerificationMethod(proof as JObject, options));
var messageCount = Service.GetTotalMessageCount(proofData);
var verifyResult = Service.VerifyProof(new VerifyProofRequest(
publicKey: keyPair.ToBlsKeyPair().GetBbsKey((uint)messageCount),
proof: proofData,
messages: stringArray.Data,
nonce: nonce));
if (!verifyResult)
{
throw new Exception("Invalid signature proof");
}
return(Task.CompletedTask);
}
