Ed25519phSigner
using Org.BouncyCastle.Crypto.Parameters;
using Org.BouncyCastle.Math.EC.Rfc8032;
using System;
namespace Org.BouncyCastle.Crypto.Signers
{
public class Ed25519phSigner : ISigner
{
private readonly IDigest prehash = Ed25519.CreatePrehash();
private readonly byte[] context;
private bool forSigning;
private Ed25519PrivateKeyParameters privateKey;
private Ed25519PublicKeyParameters publicKey;
public virtual string AlgorithmName => "Ed25519ph";
public Ed25519phSigner(byte[] context)
{
if (context == null)
throw new ArgumentNullException("context");
this.context = (byte[])context.Clone();
}
public virtual void Init(bool forSigning, ICipherParameters parameters)
{
this.forSigning = forSigning;
if (forSigning) {
privateKey = (Ed25519PrivateKeyParameters)parameters;
publicKey = null;
} else {
privateKey = null;
publicKey = (Ed25519PublicKeyParameters)parameters;
}
Reset();
}
public virtual void Update(byte b)
{
prehash.Update(b);
}
public virtual void BlockUpdate(byte[] buf, int off, int len)
{
prehash.BlockUpdate(buf, off, len);
}
public virtual int GetMaxSignatureSize()
{
return Ed25519.SignatureSize;
}
public virtual byte[] GenerateSignature()
{
if (!forSigning || privateKey == null)
throw new InvalidOperationException("Ed25519phSigner not initialised for signature generation.");
byte[] array = new byte[Ed25519.PrehashSize];
if (Ed25519.PrehashSize != prehash.DoFinal(array, 0))
throw new InvalidOperationException("Prehash calculation failed");
byte[] array2 = new byte[Ed25519PrivateKeyParameters.SignatureSize];
privateKey.Sign(Ed25519.Algorithm.Ed25519ph, context, array, 0, Ed25519.PrehashSize, array2, 0);
return array2;
}
public virtual bool VerifySignature(byte[] signature)
{
if (forSigning || publicKey == null)
throw new InvalidOperationException("Ed25519phSigner not initialised for verification");
if (Ed25519.SignatureSize != signature.Length) {
prehash.Reset();
return false;
}
byte[] array = new byte[Ed25519.PrehashSize];
if (Ed25519.PrehashSize != prehash.DoFinal(array, 0))
throw new InvalidOperationException("Prehash calculation failed");
return publicKey.Verify(Ed25519.Algorithm.Ed25519ph, context, array, 0, Ed25519.PrehashSize, signature, 0);
}
public void Reset()
{
prehash.Reset();
}
}
}