public ContentBlinder(RsaKeyParameters publicKey, string groupName)
{
RsaBlindingFactorGenerator blindingFactorGenerator = new RsaBlindingFactorGenerator();
blindingFactorGenerator.Init(publicKey);
BigInteger blindingFactor = blindingFactorGenerator.GenerateBlindingFactor();
blindingParams = new RsaBlindingParameters(publicKey, blindingFactor);
SaveBlindFactor(groupName, blindingFactor);
}
public PcGame(byte[] gameData, RsaKeyParameters pub)
{
this.gameData = gameData;
var blindingFactorGenerator = new RsaBlindingFactorGenerator();
blindingFactorGenerator.Init(pub);
var blindingFactor = blindingFactorGenerator.GenerateBlindingFactor();
blindingParams = new RsaBlindingParameters(pub, blindingFactor);
}
private void testSig(
int id,
RsaKeyParameters pub,
RsaKeyParameters prv,
byte[] slt,
byte[] msg,
byte[] sig)
{
RsaBlindingFactorGenerator blindFactorGen = new RsaBlindingFactorGenerator();
RsaBlindingEngine blindingEngine = new RsaBlindingEngine();
PssSigner blindSigner = new PssSigner(blindingEngine, new Sha1Digest(), 20);
PssSigner signer = new PssSigner(new RsaEngine(), new Sha1Digest(), 20);
blindFactorGen.Init(pub);
BigInteger blindFactor = blindFactorGen.GenerateBlindingFactor();
RsaBlindingParameters parameters = new RsaBlindingParameters(pub, blindFactor);
// generate a blind signature
blindSigner.Init(true, new ParametersWithRandom(parameters, new FixedRandom(slt)));
blindSigner.BlockUpdate(msg, 0, msg.Length);
byte[] blindedData = blindSigner.GenerateSignature();
RsaEngine signerEngine = new RsaEngine();
signerEngine.Init(true, prv);
byte[] blindedSig = signerEngine.ProcessBlock(blindedData, 0, blindedData.Length);
// unblind the signature
blindingEngine.Init(false, parameters);
byte[] s = blindingEngine.ProcessBlock(blindedSig, 0, blindedSig.Length);
//signature verification
if (!AreEqual(s, sig))
{
Fail("test " + id + " failed generation");
}
//verify signature with PssSigner
signer.Init(false, pub);
signer.BlockUpdate(msg, 0, msg.Length);
if (!signer.VerifySignature(s))
{
Fail("test " + id + " failed PssSigner verification");
}
}
public Protocoin(RsaKeyParameters pub)
{
// Create a 128-bit globally unique ID for the coin.
coinID = Util.GetRandomBytes(16);
// Generate a blinding factor using the bank's public key.
RsaBlindingFactorGenerator blindingFactorGenerator
= new RsaBlindingFactorGenerator();
blindingFactorGenerator.Init(pub);
BigInteger blindingFactor
= blindingFactorGenerator.GenerateBlindingFactor();
blindingParams = new RsaBlindingParameters(pub, blindingFactor);
}
private bool isProcessingOkay(
RsaKeyParameters pub,
RsaKeyParameters prv,
byte[] data,
SecureRandom random)
{
RsaBlindingFactorGenerator blindFactorGen = new RsaBlindingFactorGenerator();
RsaBlindingEngine blindingEngine = new RsaBlindingEngine();
PssSigner blindSigner = new PssSigner(blindingEngine, new Sha1Digest(), 20);
PssSigner pssEng = new PssSigner(new RsaEngine(), new Sha1Digest(), 20);
random.NextBytes(data);
blindFactorGen.Init(pub);
BigInteger blindFactor = blindFactorGen.GenerateBlindingFactor();
RsaBlindingParameters parameters = new RsaBlindingParameters(pub, blindFactor);
// generate a blind signature
blindSigner.Init(true, new ParametersWithRandom(parameters, random));
blindSigner.BlockUpdate(data, 0, data.Length);
byte[] blindedData = blindSigner.GenerateSignature();
RsaEngine signerEngine = new RsaEngine();
signerEngine.Init(true, prv);
byte[] blindedSig = signerEngine.ProcessBlock(blindedData, 0, blindedData.Length);
// unblind the signature
blindingEngine.Init(false, parameters);
byte[] s = blindingEngine.ProcessBlock(blindedSig, 0, blindedSig.Length);
//verify signature with PssSigner
pssEng.Init(false, pub);
pssEng.BlockUpdate(data, 0, data.Length);
return(pssEng.VerifySignature(s));
}
public (BigInteger BlindingFactor, byte[] BlindedData) Blind(byte[] data)
{
// generate blinding factor with pubkey
var blindingFactorGenerator = new RsaBlindingFactorGenerator();
blindingFactorGenerator.Init(KeyParameters);
BigInteger blindingFactor = blindingFactorGenerator.GenerateBlindingFactor();
// blind data
var blindingParams = new RsaBlindingParameters(KeyParameters, blindingFactor);
var blinder = new PssSigner(
cipher: new RsaBlindingEngine(),
digest: new Sha256Digest(),
saltLen: 32);
blinder.Init(forSigning: true, parameters: blindingParams);
blinder.BlockUpdate(data, 0, data.Length);
byte[] blindedData = blinder.GenerateSignature();
return(blindingFactor, blindedData);
}
