public Packet ReadPacket()
{
int hdr = this.ReadByte();
if (hdr < 0)
{
return(null);
}
if ((hdr & 0x80) == 0)
{
throw new IOException("invalid header encountered");
}
bool newPacket = (hdr & 0x40) != 0;
PacketTag tag = 0;
int bodyLen = 0;
bool partial = false;
if (newPacket)
{
tag = (PacketTag)(hdr & 0x3f);
int l = this.ReadByte();
if (l < 192)
{
bodyLen = l;
}
else if (l <= 223)
{
int b = m_in.ReadByte();
bodyLen = ((l - 192) << 8) + (b) + 192;
}
else if (l == 255)
{
bodyLen = (m_in.ReadByte() << 24) | (m_in.ReadByte() << 16)
| (m_in.ReadByte() << 8) | m_in.ReadByte();
}
else
{
partial = true;
bodyLen = 1 << (l & 0x1f);
}
}
else
{
int lengthType = hdr & 0x3;
tag = (PacketTag)((hdr & 0x3f) >> 2);
switch (lengthType)
{
case 0:
bodyLen = this.ReadByte();
break;
case 1:
bodyLen = (this.ReadByte() << 8) | this.ReadByte();
break;
case 2:
bodyLen = (this.ReadByte() << 24) | (this.ReadByte() << 16)
| (this.ReadByte() << 8) | this.ReadByte();
break;
case 3:
partial = true;
break;
default:
throw new IOException("unknown length type encountered");
}
}
BcpgInputStream objStream;
if (bodyLen == 0 && partial)
{
objStream = this;
}
else
{
PartialInputStream pis = new PartialInputStream(this, partial, bodyLen);
objStream = new BcpgInputStream(pis);
}
switch (tag)
{
case PacketTag.Reserved:
return(new InputStreamPacket(objStream));
case PacketTag.PublicKeyEncryptedSession:
return(new PublicKeyEncSessionPacket(objStream));
case PacketTag.Signature:
return(new SignaturePacket(objStream));
case PacketTag.SymmetricKeyEncryptedSessionKey:
return(new SymmetricKeyEncSessionPacket(objStream));
case PacketTag.OnePassSignature:
return(new OnePassSignaturePacket(objStream));
case PacketTag.SecretKey:
return(new SecretKeyPacket(objStream));
case PacketTag.PublicKey:
return(new PublicKeyPacket(objStream));
case PacketTag.SecretSubkey:
return(new SecretSubkeyPacket(objStream));
case PacketTag.CompressedData:
return(new CompressedDataPacket(objStream));
case PacketTag.SymmetricKeyEncrypted:
return(new SymmetricEncDataPacket(objStream));
case PacketTag.Marker:
return(new MarkerPacket(objStream));
case PacketTag.LiteralData:
return(new LiteralDataPacket(objStream));
case PacketTag.Trust:
return(new TrustPacket(objStream));
case PacketTag.UserId:
return(new UserIdPacket(objStream));
case PacketTag.UserAttribute:
return(new UserAttributePacket(objStream));
case PacketTag.PublicSubkey:
return(new PublicSubkeyPacket(objStream));
case PacketTag.SymmetricEncryptedIntegrityProtected:
return(new SymmetricEncIntegrityPacket(objStream));
case PacketTag.ModificationDetectionCode:
return(new ModDetectionCodePacket(objStream));
case PacketTag.Experimental1:
case PacketTag.Experimental2:
case PacketTag.Experimental3:
case PacketTag.Experimental4:
return(new ExperimentalPacket(tag, objStream));
default:
throw new IOException("unknown packet type encountered: " + tag);
}
}
public MarkerPacket(
BcpgInputStream bcpgIn)
{
bcpgIn.ReadFully(marker);
}
internal SymmetricEncIntegrityPacket(
BcpgInputStream bcpgIn)
: base(bcpgIn)
{
version = bcpgIn.ReadByte();
}
internal CompressedDataPacket(
BcpgInputStream bcpgIn)
: base(bcpgIn)
{
this.algorithm = (CompressionAlgorithmTag)bcpgIn.ReadByte();
}
public UserIdPacket(
BcpgInputStream bcpgIn)
{
this.idData = bcpgIn.ReadAll();
}
internal SignaturePacket(
BcpgInputStream bcpgIn)
{
version = bcpgIn.ReadByte();
if (version == 3 || version == 2)
{
// int l =
bcpgIn.ReadByte();
signatureType = bcpgIn.ReadByte();
creationTime = (((long)bcpgIn.ReadByte() << 24) | ((long)bcpgIn.ReadByte() << 16)
| ((long)bcpgIn.ReadByte() << 8) | (uint)bcpgIn.ReadByte()) * 1000L;
keyId |= (long)bcpgIn.ReadByte() << 56;
keyId |= (long)bcpgIn.ReadByte() << 48;
keyId |= (long)bcpgIn.ReadByte() << 40;
keyId |= (long)bcpgIn.ReadByte() << 32;
keyId |= (long)bcpgIn.ReadByte() << 24;
keyId |= (long)bcpgIn.ReadByte() << 16;
keyId |= (long)bcpgIn.ReadByte() << 8;
keyId |= (uint)bcpgIn.ReadByte();
keyAlgorithm = (PublicKeyAlgorithmTag)bcpgIn.ReadByte();
hashAlgorithm = (HashAlgorithmTag)bcpgIn.ReadByte();
}
else if (version == 4)
{
signatureType = bcpgIn.ReadByte();
keyAlgorithm = (PublicKeyAlgorithmTag)bcpgIn.ReadByte();
hashAlgorithm = (HashAlgorithmTag)bcpgIn.ReadByte();
int hashedLength = (bcpgIn.ReadByte() << 8) | bcpgIn.ReadByte();
byte[] hashed = new byte[hashedLength];
bcpgIn.ReadFully(hashed);
//
// read the signature sub packet data.
//
SignatureSubpacketsParser sIn = new SignatureSubpacketsParser(
new MemoryStream(hashed, false));
IList v = Platform.CreateArrayList();
SignatureSubpacket sub;
while ((sub = sIn.ReadPacket()) != null)
{
v.Add(sub);
}
hashedData = new SignatureSubpacket[v.Count];
for (int i = 0; i != hashedData.Length; i++)
{
SignatureSubpacket p = (SignatureSubpacket)v[i];
if (p is IssuerKeyId)
{
keyId = ((IssuerKeyId)p).KeyId;
}
else if (p is SignatureCreationTime)
{
creationTime = DateTimeUtilities.DateTimeToUnixMs(
((SignatureCreationTime)p).GetTime());
}
hashedData[i] = p;
}
int unhashedLength = (bcpgIn.ReadByte() << 8) | bcpgIn.ReadByte();
byte[] unhashed = new byte[unhashedLength];
bcpgIn.ReadFully(unhashed);
sIn = new SignatureSubpacketsParser(new MemoryStream(unhashed, false));
v.Clear();
while ((sub = sIn.ReadPacket()) != null)
{
v.Add(sub);
}
unhashedData = new SignatureSubpacket[v.Count];
for (int i = 0; i != unhashedData.Length; i++)
{
SignatureSubpacket p = (SignatureSubpacket)v[i];
if (p is IssuerKeyId)
{
keyId = ((IssuerKeyId)p).KeyId;
}
unhashedData[i] = p;
}
}
else
{
throw new Exception("unsupported version: " + version);
}
fingerprint = new byte[2];
bcpgIn.ReadFully(fingerprint);
switch (keyAlgorithm)
{
case PublicKeyAlgorithmTag.RsaGeneral:
case PublicKeyAlgorithmTag.RsaSign:
MPInteger v = new MPInteger(bcpgIn);
signature = new MPInteger[] { v };
break;
case PublicKeyAlgorithmTag.Dsa:
MPInteger r = new MPInteger(bcpgIn);
MPInteger s = new MPInteger(bcpgIn);
signature = new MPInteger[] { r, s };
break;
case PublicKeyAlgorithmTag.ElGamalEncrypt: // yep, this really does happen sometimes.
case PublicKeyAlgorithmTag.ElGamalGeneral:
MPInteger p = new MPInteger(bcpgIn);
MPInteger g = new MPInteger(bcpgIn);
MPInteger y = new MPInteger(bcpgIn);
signature = new MPInteger[] { p, g, y };
break;
default:
if (keyAlgorithm >= PublicKeyAlgorithmTag.Experimental_1 && keyAlgorithm <= PublicKeyAlgorithmTag.Experimental_11)
{
signature = null;
MemoryStream bOut = new MemoryStream();
int ch;
while ((ch = bcpgIn.ReadByte()) >= 0)
{
bOut.WriteByte((byte)ch);
}
signatureEncoding = bOut.ToArray();
}
else
{
throw new IOException("unknown signature key algorithm: " + keyAlgorithm);
}
break;
}
}
