private void VerifyHostKeyByDSS(SSH2DataReader pubkey, byte[] sigbody, byte[] hash)
{
BigInteger p = pubkey.ReadMPInt();
BigInteger q = pubkey.ReadMPInt();
BigInteger g = pubkey.ReadMPInt();
BigInteger y = pubkey.ReadMPInt();
Debug.Assert(pubkey.Rest==0);
//Debug.WriteLine(p.ToHexString());
//Debug.WriteLine(q.ToHexString());
//Debug.WriteLine(g.ToHexString());
//Debug.WriteLine(y.ToHexString());
DSAPublicKey pk = new DSAPublicKey(p,g,q,y);
pk.Verify(sigbody, new SHA1CryptoServiceProvider().ComputeHash(hash));
_cInfo._hostkey = pk;
}
private void VerifyHostKeyByRSA(SSH2DataReader pubkey, byte[] sigbody, byte[] hash)
{
BigInteger exp = pubkey.ReadMPInt();
BigInteger mod = pubkey.ReadMPInt();
Debug.Assert(pubkey.Rest==0);
//Debug.WriteLine(exp.ToHexString());
//Debug.WriteLine(mod.ToHexString());
RSAPublicKey pk = new RSAPublicKey(exp, mod);
pk.VerifyWithSHA1(sigbody, new SHA1CryptoServiceProvider().ComputeHash(hash));
_cInfo._hostkey = pk;
}
private bool ProcessKEXDHREPLY(SSH2Packet packet)
{
//Round2 receives response
SSH2DataReader re = new SSH2DataReader(packet.Data);
PacketType h = re.ReadPacketType();
if(h!=PacketType.SSH_MSG_KEXDH_REPLY) throw new SSHException(String.Format("KeyExchange response is not KEXDH_REPLY but {0}", h));
byte[] key_and_cert = re.ReadString();
BigInteger f = re.ReadMPInt();
byte[] signature = re.ReadString();
Debug.Assert(re.Rest==0);
//Round3 calc hash H
SSH2DataWriter wr = new SSH2DataWriter();
_k = f.modPow(_x, DH_PRIME);
wr = new SSH2DataWriter();
wr.Write(_cInfo._clientVersionString);
wr.Write(_cInfo._serverVersionString);
wr.WriteAsString(_clientKEXINITPayload);
wr.WriteAsString(_serverKEXINITPayload);
wr.WriteAsString(key_and_cert);
wr.Write(_e);
wr.Write(f);
wr.Write(_k);
_hash = new SHA1CryptoServiceProvider().ComputeHash(wr.ToByteArray());
if(!VerifyHostKey(key_and_cert, signature, _hash)) return false;
//Debug.WriteLine("hash="+DebugUtil.DumpByteArray(hash));
if(_sessionID==null) _sessionID = _hash;
return true;
}