GenericSigner
using Org.BouncyCastle.Crypto.Parameters;
using Org.BouncyCastle.Security;
using Org.BouncyCastle.Utilities;
using System;
namespace Org.BouncyCastle.Crypto.Signers
{
public class GenericSigner : ISigner
{
private readonly IAsymmetricBlockCipher engine;
private readonly IDigest digest;
private bool forSigning;
public virtual string AlgorithmName => "Generic(" + engine.AlgorithmName + "/" + digest.AlgorithmName + ")";
public GenericSigner(IAsymmetricBlockCipher engine, IDigest digest)
{
this.engine = engine;
this.digest = digest;
}
public virtual void Init(bool forSigning, ICipherParameters parameters)
{
this.forSigning = forSigning;
ParametersWithRandom parametersWithRandom = parameters as ParametersWithRandom;
AsymmetricKeyParameter asymmetricKeyParameter = (parametersWithRandom == null) ? ((AsymmetricKeyParameter)parameters) : ((AsymmetricKeyParameter)parametersWithRandom.Parameters);
if (forSigning && !asymmetricKeyParameter.IsPrivate)
throw new InvalidKeyException("Signing requires private key.");
if (!forSigning && asymmetricKeyParameter.IsPrivate)
throw new InvalidKeyException("Verification requires public key.");
Reset();
engine.Init(forSigning, parameters);
}
public virtual void Update(byte input)
{
digest.Update(input);
}
public virtual void BlockUpdate(byte[] input, int inOff, int inLen)
{
digest.BlockUpdate(input, inOff, inLen);
}
public virtual void BlockUpdate(ReadOnlySpan<byte> input)
{
digest.BlockUpdate(input);
}
public virtual int GetMaxSignatureSize()
{
return engine.GetOutputBlockSize();
}
public virtual byte[] GenerateSignature()
{
if (!forSigning)
throw new InvalidOperationException("GenericSigner not initialised for signature generation.");
byte[] array = new byte[digest.GetDigestSize()];
digest.DoFinal(array, 0);
return engine.ProcessBlock(array, 0, array.Length);
}
public virtual bool VerifySignature(byte[] signature)
{
if (!forSigning) {
byte[] array = new byte[digest.GetDigestSize()];
digest.DoFinal(array, 0);
try {
byte[] array2 = engine.ProcessBlock(signature, 0, signature.Length);
if (array2.Length < array.Length) {
byte[] array3 = new byte[array.Length];
Array.Copy(array2, 0, array3, array3.Length - array2.Length, array2.Length);
array2 = array3;
}
return Arrays.FixedTimeEquals(array2, array);
} catch (Exception) {
return false;
}
}
throw new InvalidOperationException("GenericSigner not initialised for verification");
}
public virtual void Reset()
{
digest.Reset();
}
}
}