/// <summary>
/// Signs the passed in data with a private key
/// </summary>
/// <param name="privateKey">the private key used to create the signature</param>
/// <param name="data">The data to sign</param>
/// <returns>the signature as a byte array</returns>
public byte[] Sign(byte[] privateKey, byte[] data)
{
var signer = new ECNRSigner();
var privKey = (ECPrivateKeyParameters)CreateAsymmetricKeyParameterFromPrivateKeyInfo(privateKey);
signer.Init(true, privKey);
var bigIntSig = signer.GenerateSignature(data);
var signature = new List <byte>();
signature.AddRange(bigIntSig[0].ToByteArrayUnsigned());
signature.AddRange(bigIntSig[1].ToByteArrayUnsigned());
return(signature.ToArray());
}
private void ecNR239bitPrime()
{
BigInteger n = new BigInteger("883423532389192164791648750360308884807550341691627752275345424702807307");
FpCurve curve = new FpCurve(
new BigInteger("883423532389192164791648750360308885314476597252960362792450860609699839"), // q
new BigInteger("7fffffffffffffffffffffff7fffffffffff8000000000007ffffffffffc", 16), // a
new BigInteger("6b016c3bdcf18941d0d654921475ca71a9db2fb27d1d37796185c2942c0a", 16), // b
n, BigInteger.One);
ECDomainParameters parameters = new ECDomainParameters(
curve,
curve.DecodePoint(Hex.Decode("020ffa963cdca8816ccc33b8642bedf905c3d358573d3f27fbbd3b3cb9aaaf")), // G
n);
ECPrivateKeyParameters priKey = new ECPrivateKeyParameters(
new BigInteger("876300101507107567501066130761671078357010671067781776716671676178726717"), // d
parameters);
ECNRSigner ecnr = new ECNRSigner();
ParametersWithRandom param = new ParametersWithRandom(priKey, k);
ecnr.Init(true, param);
byte[] message = new BigInteger("968236873715988614170569073515315707566766479517").ToByteArray();
BigInteger[] sig = ecnr.GenerateSignature(message);
if (!r.Equals(sig[0]))
{
Fail("r component wrong.", r, sig[0]);
}
if (!s.Equals(sig[1]))
{
Fail("s component wrong.", s, sig[1]);
}
// Verify the signature
ECPublicKeyParameters pubKey = new ECPublicKeyParameters(
curve.DecodePoint(Hex.Decode("025b6dc53bc61a2548ffb0f671472de6c9521a9d2d2534e65abfcbd5fe0c70")), // Q
parameters);
ecnr.Init(false, pubKey);
if (!ecnr.VerifySignature(message, sig[0], sig[1]))
{
Fail("signature fails");
}
}
/// <summary>
/// Verifies a signature to be authentic
/// </summary>
/// <param name="originalSignature">The signature which is be verified</param>
/// <param name="publicKey">the public key used for the verification</param>
/// <param name="data">the data which is signed</param>
/// <returns>true if signature is authentic, false if not</returns>
public bool Verify(byte[] originalSignature, byte[] publicKey, byte[] data)
{
var signer = new ECNRSigner();
var pubKey = (ECPublicKeyParameters)CreateAsymmetricKeyParameterFromPublicKeyInfo(publicKey);
signer.Init(false, pubKey);
var r = new byte[originalSignature.Length / 2];
var s = new byte[originalSignature.Length / 2];
Array.Copy(originalSignature, r, r.Length);
Array.Copy(originalSignature, r.Length, s, 0, s.Length);
var R = new BigInteger(1, r);
var S = new BigInteger(1, s);
return(signer.VerifySignature(data, R, S));
}
