PgpOnePassSignature
using Org.BouncyCastle.Crypto;
using Org.BouncyCastle.Security;
using System;
using System.IO;
namespace Org.BouncyCastle.Bcpg.OpenPgp
{
public class PgpOnePassSignature
{
private readonly OnePassSignaturePacket sigPack;
private readonly int signatureType;
private ISigner sig;
private byte lastb;
public long KeyId => sigPack.KeyId;
public int SignatureType => sigPack.SignatureType;
public HashAlgorithmTag HashAlgorithm => sigPack.HashAlgorithm;
public PublicKeyAlgorithmTag KeyAlgorithm => sigPack.KeyAlgorithm;
private static OnePassSignaturePacket Cast(Packet packet)
{
OnePassSignaturePacket onePassSignaturePacket = packet as OnePassSignaturePacket;
if (onePassSignaturePacket != null)
return onePassSignaturePacket;
throw new IOException("unexpected packet in stream: " + packet?.ToString());
}
internal PgpOnePassSignature(BcpgInputStream bcpgInput)
: this(Cast(bcpgInput.ReadPacket()))
{
}
internal PgpOnePassSignature(OnePassSignaturePacket sigPack)
{
this.sigPack = sigPack;
signatureType = sigPack.SignatureType;
}
public void InitVerify(PgpPublicKey pubKey)
{
lastb = 0;
AsymmetricKeyParameter key = pubKey.GetKey();
try {
sig = PgpUtilities.CreateSigner(sigPack.KeyAlgorithm, sigPack.HashAlgorithm, key);
} catch (Exception innerException) {
throw new PgpException("can't set up signature object.", innerException);
}
try {
sig.Init(false, key);
} catch (InvalidKeyException innerException2) {
throw new PgpException("invalid key.", innerException2);
}
}
public void Update(byte b)
{
if (signatureType == 1)
DoCanonicalUpdateByte(b);
else
sig.Update(b);
}
private void DoCanonicalUpdateByte(byte b)
{
switch (b) {
case 13:
DoUpdateCRLF();
break;
case 10:
if (lastb != 13)
DoUpdateCRLF();
break;
default:
sig.Update(b);
break;
}
lastb = b;
}
private void DoUpdateCRLF()
{
sig.Update(13);
sig.Update(10);
}
public void Update(params byte[] bytes)
{
Update(bytes, 0, bytes.Length);
}
public void Update(byte[] bytes, int off, int length)
{
Update(bytes.AsSpan(off, length));
}
public void Update(ReadOnlySpan<byte> input)
{
if (signatureType == 1) {
for (int i = 0; i < input.Length; i++) {
DoCanonicalUpdateByte(input[i]);
}
} else
sig.BlockUpdate(input);
}
public bool Verify(PgpSignature pgpSig)
{
byte[] signatureTrailer = pgpSig.GetSignatureTrailer();
sig.BlockUpdate(signatureTrailer, 0, signatureTrailer.Length);
return sig.VerifySignature(pgpSig.GetSignature());
}
public byte[] GetEncoded()
{
MemoryStream memoryStream = new MemoryStream();
Encode(memoryStream);
return memoryStream.ToArray();
}
public void Encode(Stream outStr)
{
BcpgOutputStream.Wrap(outStr).WritePacket(sigPack);
}
}
}