public JToken CreateProof(CreateProofOptions options, JsonLdProcessorOptions processorOptions)
{
var(document, proofs) = options.Document.GetProofs(processorOptions);
var proof = new BbsBlsSignature2020(proofs.FirstOrDefault() ?? throw new Exception("Proof not found"));
proof.Context = Constants.SECURITY_CONTEXT_V2_URL;
var signature = Convert.FromBase64String(proof.ProofValue);
var derivedProof = JsonLdProcessor.Compact(new BbsBlsSignatureProof2020(), Constants.SECURITY_CONTEXT_V2_URL, processorOptions);
var documentStatements = BbsBlsSignature2020Suite.CreateVerifyDocumentData(document, processorOptions);
var proofStatements = BbsBlsSignature2020Suite.CreateVerifyProofData(proof, processorOptions);
var transformedInputDocumentStatements = documentStatements.Select(TransformBlankNodeToId).ToArray();
var compactInputDocument = Helpers.FromRdf(transformedInputDocumentStatements);
var revealDocument = JsonLdProcessor.Frame(compactInputDocument, options.ProofRequest, processorOptions);
var revealDocumentStatements = BbsBlsSignature2020Suite.CreateVerifyDocumentData(revealDocument, processorOptions);
var numberOfProofStatements = proofStatements.Count();
var proofRevealIndicies = EnumerableFromInt(numberOfProofStatements).ToArray();
var documentRevealIndicies = revealDocumentStatements.Select(x => Array.IndexOf(transformedInputDocumentStatements, x) + numberOfProofStatements).ToArray();
if (documentRevealIndicies.Count() != revealDocumentStatements.Count())
{
throw new Exception("Some statements in the reveal document not found in original proof");
}
var revealIndicies = proofRevealIndicies.Concat(documentRevealIndicies);
derivedProof["nonce"] = options.Nonce ?? Guid.NewGuid().ToString();
//Combine all the input statements that
//were originally signed to generate the proof
var allInputStatements = proofStatements.Concat(documentStatements);
var verificationMethod = BbsBlsSignature2020Suite.GetVerificationMethod(proofs.First(), processorOptions);
var outputProof = BbsProvider.CreateProof(new CreateProofRequest(
publicKey: verificationMethod.ToBlsKeyPair().GeyBbsKeyPair((uint)allInputStatements.Count()),
messages: GetProofMessages(allInputStatements.ToArray(), revealIndicies).ToArray(),
signature: signature,
blindingFactor: null,
nonce: derivedProof["nonce"].ToString()));
// Set the proof value on the derived proof
derivedProof["proofValue"] = Convert.ToBase64String(outputProof);
// Set the relevant proof elements on the derived proof from the input proof
derivedProof["verificationMethod"] = proof["verificationMethod"];
derivedProof["proofPurpose"] = proof["proofPurpose"];
derivedProof["created"] = proof["created"];
revealDocument["proof"] = derivedProof;
return(revealDocument);
}
public bool VerifyProof(VerifyProofOptions options, JsonLdProcessorOptions processorOptions)
{
options.Proof["type"] = "https://w3c-ccg.github.io/ldp-bbs2020/context/v1#BbsBlsSignature2020";
var documentStatements = BbsBlsSignature2020Suite.CreateVerifyDocumentData(options.Document, processorOptions);
var proofStatements = BbsBlsSignature2020Suite.CreateVerifyProofData(options.Proof, processorOptions);
var transformedInputDocumentStatements = documentStatements.Select(TransformIdToBlankNode).ToArray();
var statementsToVerify = proofStatements.Concat(transformedInputDocumentStatements);
var verificationMethod = BbsBlsSignature2020Suite.GetVerificationMethod(options.Proof, processorOptions);
var proofData = Convert.FromBase64String(options.Proof["proofValue"].ToString());
var nonce = options.Proof["nonce"].ToString();
var verifyResult = BbsProvider.VerifyProof(new VerifyProofRequest(
publicKey: verificationMethod.ToBlsKeyPair().GeyBbsKeyPair((uint)statementsToVerify.Count()),
proof: proofData,
messages: GetIndexedMessages(statementsToVerify.ToArray()).ToArray(),
nonce: nonce));
return(verifyResult == SignatureProofStatus.Success);
}
