public Token Append(RNGCryptoServiceProvider rng, KeyPair keypair, byte[] message)
{
TokenSignature signature = this.Signature.Sign(rng, keypair, message);
Token token = new Token(this.Blocks, this.Keys, signature);
token.Blocks.Add(message);
token.Keys.Add(keypair.PublicKey);
return(token);
}
public Token(RNGCryptoServiceProvider rng, KeyPair keypair, byte[] message)
{
this.Signature = new TokenSignature(rng, keypair, message);
this.Blocks = new List <byte[]> {
message
};
this.Keys = new List <RistrettoElement> {
keypair.PublicKey
};
}
/// <summary>
/// Generates a new valid signature from an existing one, a private key and a message
/// </summary>
/// <param name="rng"></param>
/// <param name="keypair"></param>
/// <param name="message"></param>
/// <returns></returns>
public TokenSignature Sign(RNGCryptoServiceProvider rng, KeyPair keypair, byte[] message)
{
byte[] randomData = new byte[64];
rng.GetBytes(randomData);
Scalar r = Scalar.FromBytesModOrderWide(randomData);
var ristretto = Constants.RISTRETTO_GENERATOR.Multiply(r);
var ristrettoElements = new List <RistrettoElement> {
ristretto
};
Scalar d = HashPoints(ristrettoElements);
Scalar e = HashMessage(keypair.PublicKey, message);
Scalar z = r.Multiply(d).Subtract(e.Multiply(keypair.PrivateKey));
TokenSignature sig = new TokenSignature(this.Parameters, this.Z.Add(z));
sig.Parameters.Add(ristretto);
return(sig);
}
public Token(IList <byte[]> blocks, IList <RistrettoElement> keys, TokenSignature signature)
{
this.Signature = signature;
this.Blocks = blocks;
this.Keys = keys;
}
