internal RecordStream(
TlsProtocolHandler handler,
Stream inStr,
Stream outStr)
{
this.handler = handler;
this.inStr = inStr;
this.outStr = outStr;
hash1 = new CombinedHash();
hash2 = new CombinedHash();
this.readSuite = new TlsNullCipherSuite();
this.writeSuite = this.readSuite;
}
internal RecordStream(
TlsProtocolHandler handler,
Stream inStr,
Stream outStr)
{
this.handler = handler;
this.inStr = inStr;
this.outStr = outStr;
hash1 = new CombinedHash();
hash2 = new CombinedHash();
this.readSuite = new TlsNullCipherSuite();
this.writeSuite = this.readSuite;
}
private void processHandshake()
{
bool read;
do
{
read = false;
/*
* We need the first 4 bytes, they contain type and length of
* the message.
*/
if (handshakeQueue.Available >= 4)
{
byte[] beginning = new byte[4];
handshakeQueue.Read(beginning, 0, 4, 0);
MemoryStream bis = new MemoryStream(beginning, false);
short type = TlsUtilities.ReadUint8(bis);
int len = TlsUtilities.ReadUint24(bis);
/*
* Check if we have enough bytes in the buffer to read
* the full message.
*/
if (handshakeQueue.Available >= (len + 4))
{
/*
* Read the message.
*/
byte[] buf = new byte[len];
handshakeQueue.Read(buf, 0, len, 4);
handshakeQueue.RemoveData(len + 4);
/*
* If it is not a finished message, update our hashes
* we prepare for the finish message.
*/
if (type != HP_FINISHED)
{
rs.hash1.BlockUpdate(beginning, 0, 4);
rs.hash2.BlockUpdate(beginning, 0, 4);
rs.hash1.BlockUpdate(buf, 0, len);
rs.hash2.BlockUpdate(buf, 0, len);
}
/*
* Now, parse the message.
*/
MemoryStream inStr = new MemoryStream(buf, false);
/*
* Check the type.
*/
switch (type)
{
case HP_CERTIFICATE:
{
switch (connection_state)
{
case CS_SERVER_HELLO_RECEIVED:
{
/*
* Parse the certificates.
*/
Certificate cert = Certificate.Parse(inStr);
AssertEmpty(inStr);
X509CertificateStructure x509Cert = cert.certs[0];
SubjectPublicKeyInfo keyInfo = x509Cert.SubjectPublicKeyInfo;
try
{
this.serverPublicKey = PublicKeyFactory.CreateKey(keyInfo);
}
catch (Exception)
{
this.FailWithError(AL_fatal, AP_unsupported_certificate);
}
// Sanity check the PublicKeyFactory
if (this.serverPublicKey.IsPrivate)
{
this.FailWithError(AL_fatal, AP_internal_error);
}
/*
* Perform various checks per RFC2246 7.4.2
* TODO "Unless otherwise specified, the signing algorithm for the certificate
* must be the same as the algorithm for the certificate key."
*/
switch (this.chosenCipherSuite.KeyExchangeAlgorithm)
{
case TlsCipherSuite.KE_RSA:
if (!(this.serverPublicKey is RsaKeyParameters))
{
this.FailWithError(AL_fatal, AP_certificate_unknown);
}
validateKeyUsage(x509Cert, KeyUsage.KeyEncipherment);
break;
case TlsCipherSuite.KE_DHE_RSA:
if (!(this.serverPublicKey is RsaKeyParameters))
{
this.FailWithError(AL_fatal, AP_certificate_unknown);
}
validateKeyUsage(x509Cert, KeyUsage.DigitalSignature);
break;
case TlsCipherSuite.KE_DHE_DSS:
if (!(this.serverPublicKey is DsaPublicKeyParameters))
{
this.FailWithError(AL_fatal, AP_certificate_unknown);
}
break;
default:
this.FailWithError(AL_fatal, AP_unsupported_certificate);
break;
}
/*
* Verify them.
*/
if (!this.verifyer.IsValid(cert.GetCerts()))
{
this.FailWithError(AL_fatal, AP_user_canceled);
}
break;
}
default:
this.FailWithError(AL_fatal, AP_unexpected_message);
break;
}
connection_state = CS_SERVER_CERTIFICATE_RECEIVED;
read = true;
break;
}
case HP_FINISHED:
switch (connection_state)
{
case CS_SERVER_CHANGE_CIPHER_SPEC_RECEIVED:
/*
* Read the checksum from the finished message,
* it has always 12 bytes.
*/
byte[] receivedChecksum = new byte[12];
TlsUtilities.ReadFully(receivedChecksum, inStr);
AssertEmpty(inStr);
/*
* Calculate our own checksum.
*/
byte[] checksum = new byte[12];
byte[] md5andsha1 = new byte[16 + 20];
rs.hash2.DoFinal(md5andsha1, 0);
TlsUtilities.PRF(this.ms, TlsUtilities.ToByteArray("server finished"), md5andsha1, checksum);
/*
* Compare both checksums.
*/
for (int i = 0; i < receivedChecksum.Length; i++)
{
if (receivedChecksum[i] != checksum[i])
{
/*
* Wrong checksum in the finished message.
*/
this.FailWithError(AL_fatal, AP_handshake_failure);
}
}
connection_state = CS_DONE;
/*
* We are now ready to receive application data.
*/
this.appDataReady = true;
read = true;
break;
default:
this.FailWithError(AL_fatal, AP_unexpected_message);
break;
}
break;
case HP_SERVER_HELLO:
switch (connection_state)
{
case CS_CLIENT_HELLO_SEND:
/*
* Read the server hello message
*/
TlsUtilities.CheckVersion(inStr, this);
/*
* Read the server random
*/
this.serverRandom = new byte[32];
TlsUtilities.ReadFully(this.serverRandom, inStr);
/*
* Currently, we don't support session ids
*/
short sessionIdLength = TlsUtilities.ReadUint8(inStr);
byte[] sessionId = new byte[sessionIdLength];
TlsUtilities.ReadFully(sessionId, inStr);
/*
* Find out which ciphersuite the server has
* chosen. If we don't support this ciphersuite,
* the TlsCipherSuiteManager will throw an
* exception.
*/
this.chosenCipherSuite = TlsCipherSuiteManager.GetCipherSuite(
TlsUtilities.ReadUint16(inStr), this);
/*
* We support only the null compression which
* means no compression.
*/
short compressionMethod = TlsUtilities.ReadUint8(inStr);
if (compressionMethod != 0)
{
this.FailWithError(TlsProtocolHandler.AL_fatal, TlsProtocolHandler.AP_illegal_parameter);
}
AssertEmpty(inStr);
connection_state = CS_SERVER_HELLO_RECEIVED;
read = true;
break;
default:
this.FailWithError(AL_fatal, AP_unexpected_message);
break;
}
break;
case HP_SERVER_HELLO_DONE:
switch (connection_state)
{
case CS_SERVER_CERTIFICATE_RECEIVED:
case CS_SERVER_KEY_EXCHANGE_RECEIVED:
case CS_CERTIFICATE_REQUEST_RECEIVED:
// NB: Original code used case label fall-through
if (connection_state == CS_SERVER_CERTIFICATE_RECEIVED)
{
/*
* There was no server key exchange message, check
* that we are doing RSA key exchange.
*/
if (this.chosenCipherSuite.KeyExchangeAlgorithm != TlsCipherSuite.KE_RSA)
{
this.FailWithError(AL_fatal, AP_unexpected_message);
}
}
AssertEmpty(inStr);
bool isCertReq = (connection_state == CS_CERTIFICATE_REQUEST_RECEIVED);
connection_state = CS_SERVER_HELLO_DONE_RECEIVED;
if (isCertReq)
{
sendClientCertificate();
}
/*
* Send the client key exchange message, depending
* on the key exchange we are using in our
* ciphersuite.
*/
switch (this.chosenCipherSuite.KeyExchangeAlgorithm)
{
case TlsCipherSuite.KE_RSA:
{
/*
* We are doing RSA key exchange. We will
* choose a pre master secret and send it
* rsa encrypted to the server.
*
* Prepare pre master secret.
*/
pms = new byte[48];
pms[0] = 3;
pms[1] = 1;
random.NextBytes(pms, 2, 46);
/*
* Encode the pms and send it to the server.
*
* Prepare an Pkcs1Encoding with good random
* padding.
*/
RsaBlindedEngine rsa = new RsaBlindedEngine();
Pkcs1Encoding encoding = new Pkcs1Encoding(rsa);
encoding.Init(true, new ParametersWithRandom(this.serverPublicKey, this.random));
byte[] encrypted = null;
try
{
encrypted = encoding.ProcessBlock(pms, 0, pms.Length);
}
catch (InvalidCipherTextException)
{
/*
* This should never happen, only during decryption.
*/
this.FailWithError(AL_fatal, AP_internal_error);
}
/*
* Send the encrypted pms.
*/
sendClientKeyExchange(encrypted);
break;
}
case TlsCipherSuite.KE_DHE_DSS:
case TlsCipherSuite.KE_DHE_RSA:
{
/*
* Send the Client Key Exchange message for
* DHE key exchange.
*/
byte[] YcByte = BigIntegers.AsUnsignedByteArray(this.Yc);
sendClientKeyExchange(YcByte);
break;
}
default:
/*
* Problem during handshake, we don't know
* how to handle this key exchange method.
*/
this.FailWithError(AL_fatal, AP_unexpected_message);
break;
}
connection_state = CS_CLIENT_KEY_EXCHANGE_SEND;
/*
* Now, we send change cipher state
*/
byte[] cmessage = new byte[1];
cmessage[0] = 1;
rs.WriteMessage((short)RL_CHANGE_CIPHER_SPEC, cmessage, 0, cmessage.Length);
connection_state = CS_CLIENT_CHANGE_CIPHER_SPEC_SEND;
/*
* Calculate the ms
*/
this.ms = new byte[48];
byte[] randBytes = new byte[clientRandom.Length + serverRandom.Length];
Array.Copy(clientRandom, 0, randBytes, 0, clientRandom.Length);
Array.Copy(serverRandom, 0, randBytes, clientRandom.Length, serverRandom.Length);
TlsUtilities.PRF(pms, TlsUtilities.ToByteArray("master secret"), randBytes, this.ms);
/*
* Initialize our cipher suite
*/
rs.writeSuite = this.chosenCipherSuite;
rs.writeSuite.Init(this.ms, clientRandom, serverRandom);
/*
* Send our finished message.
*/
byte[] checksum = new byte[12];
byte[] md5andsha1 = new byte[16 + 20];
rs.hash1.DoFinal(md5andsha1, 0);
TlsUtilities.PRF(this.ms, TlsUtilities.ToByteArray("client finished"), md5andsha1, checksum);
MemoryStream bos2 = new MemoryStream();
TlsUtilities.WriteUint8(HP_FINISHED, bos2);
TlsUtilities.WriteUint24(12, bos2);
bos2.Write(checksum, 0, checksum.Length);
byte[] message2 = bos2.ToArray();
rs.WriteMessage((short)RL_HANDSHAKE, message2, 0, message2.Length);
this.connection_state = CS_CLIENT_FINISHED_SEND;
read = true;
break;
default:
this.FailWithError(AL_fatal, AP_handshake_failure);
break;
}
break;
case HP_SERVER_KEY_EXCHANGE:
{
switch (connection_state)
{
case CS_SERVER_CERTIFICATE_RECEIVED:
{
/*
* Check that we are doing DHE key exchange
*/
switch (this.chosenCipherSuite.KeyExchangeAlgorithm)
{
case TlsCipherSuite.KE_DHE_RSA:
{
processDHEKeyExchange(inStr, new TlsRsaSigner());
break;
}
case TlsCipherSuite.KE_DHE_DSS:
{
processDHEKeyExchange(inStr, new TlsDssSigner());
break;
}
default:
this.FailWithError(AL_fatal, AP_unexpected_message);
break;
}
break;
}
default:
this.FailWithError(AL_fatal, AP_unexpected_message);
break;
}
this.connection_state = CS_SERVER_KEY_EXCHANGE_RECEIVED;
read = true;
break;
}
case HP_CERTIFICATE_REQUEST:
switch (connection_state)
{
case CS_SERVER_CERTIFICATE_RECEIVED:
case CS_SERVER_KEY_EXCHANGE_RECEIVED:
{
// NB: Original code used case label fall-through
if (connection_state == CS_SERVER_CERTIFICATE_RECEIVED)
{
/*
* There was no server key exchange message, check
* that we are doing RSA key exchange.
*/
if (this.chosenCipherSuite.KeyExchangeAlgorithm != TlsCipherSuite.KE_RSA)
{
this.FailWithError(AL_fatal, AP_unexpected_message);
}
}
int typesLength = TlsUtilities.ReadUint8(inStr);
byte[] types = new byte[typesLength];
TlsUtilities.ReadFully(types, inStr);
int authsLength = TlsUtilities.ReadUint16(inStr);
byte[] auths = new byte[authsLength];
TlsUtilities.ReadFully(auths, inStr);
AssertEmpty(inStr);
break;
}
default:
this.FailWithError(AL_fatal, AP_unexpected_message);
break;
}
this.connection_state = CS_CERTIFICATE_REQUEST_RECEIVED;
read = true;
break;
case HP_HELLO_REQUEST:
case HP_CLIENT_KEY_EXCHANGE:
case HP_CERTIFICATE_VERIFY:
case HP_CLIENT_HELLO:
default:
// We do not support this!
this.FailWithError(AL_fatal, AP_unexpected_message);
break;
}
}
}
}while (read);
}
private void processHandshake()
{
bool read;
do
{
read = false;
/*
* We need the first 4 bytes, they contain type and length of
* the message.
*/
if (handshakeQueue.Available >= 4)
{
byte[] beginning = new byte[4];
handshakeQueue.Read(beginning, 0, 4, 0);
MemoryStream bis = new MemoryStream(beginning, false);
short type = TlsUtilities.ReadUint8(bis);
int len = TlsUtilities.ReadUint24(bis);
/*
* Check if we have enough bytes in the buffer to read
* the full message.
*/
if (handshakeQueue.Available >= (len + 4))
{
/*
* Read the message.
*/
byte[] buf = new byte[len];
handshakeQueue.Read(buf, 0, len, 4);
handshakeQueue.RemoveData(len + 4);
/*
* If it is not a finished message, update our hashes
* we prepare for the finish message.
*/
if (type != HP_FINISHED)
{
rs.hash1.BlockUpdate(beginning, 0, 4);
rs.hash2.BlockUpdate(beginning, 0, 4);
rs.hash1.BlockUpdate(buf, 0, len);
rs.hash2.BlockUpdate(buf, 0, len);
}
/*
* Now, parse the message.
*/
MemoryStream inStr = new MemoryStream(buf, false);
/*
* Check the type.
*/
switch (type)
{
case HP_CERTIFICATE:
switch (connection_state)
{
case CS_SERVER_HELLO_RECEIVED:
/*
* Parse the certificates.
*/
Certificate cert = Certificate.Parse(inStr);
AssertEmpty(inStr);
/*
* Verify them.
*/
if (!this.verifyer.IsValid(cert.GetCerts()))
{
this.FailWithError(AL_fatal, AP_user_canceled);
}
/*
* We only support RSA certificates. Lets hope
* this is one.
*/
RsaPublicKeyStructure rsaKey = null;
try
{
rsaKey = RsaPublicKeyStructure.GetInstance(
cert.certs[0].TbsCertificate.SubjectPublicKeyInfo.GetPublicKey());
}
catch (Exception)
{
/*
* Sorry, we have to fail ;-(
*/
this.FailWithError(AL_fatal, AP_unsupported_certificate);
}
/*
* Parse the servers public RSA key.
*/
this.serverRsaKey = new RsaKeyParameters(
false,
rsaKey.Modulus,
rsaKey.PublicExponent);
connection_state = CS_SERVER_CERTIFICATE_RECEIVED;
read = true;
break;
default:
this.FailWithError(AL_fatal, AP_unexpected_message);
break;
}
break;
case HP_FINISHED:
switch (connection_state)
{
case CS_SERVER_CHANGE_CIPHER_SPEC_RECEIVED:
/*
* Read the checksum from the finished message,
* it has always 12 bytes.
*/
byte[] receivedChecksum = new byte[12];
TlsUtilities.ReadFully(receivedChecksum, inStr);
AssertEmpty(inStr);
/*
* Calculate our owne checksum.
*/
byte[] checksum = new byte[12];
byte[] md5andsha1 = new byte[16 + 20];
rs.hash2.DoFinal(md5andsha1, 0);
TlsUtilities.PRF(this.ms, TlsUtilities.ToByteArray("server finished"), md5andsha1, checksum);
/*
* Compare both checksums.
*/
for (int i = 0; i < receivedChecksum.Length; i++)
{
if (receivedChecksum[i] != checksum[i])
{
/*
* Wrong checksum in the finished message.
*/
this.FailWithError(AL_fatal, AP_handshake_failure);
}
}
connection_state = CS_DONE;
/*
* We are now ready to receive application data.
*/
this.appDataReady = true;
read = true;
break;
default:
this.FailWithError(AL_fatal, AP_unexpected_message);
break;
}
break;
case HP_SERVER_HELLO:
switch (connection_state)
{
case CS_CLIENT_HELLO_SEND:
/*
* Read the server hello message
*/
TlsUtilities.CheckVersion(inStr, this);
/*
* Read the server random
*/
this.serverRandom = new byte[32];
TlsUtilities.ReadFully(this.serverRandom, inStr);
/*
* Currenty, we don't support session ids
*/
short sessionIdLength = TlsUtilities.ReadUint8(inStr);
byte[] sessionId = new byte[sessionIdLength];
TlsUtilities.ReadFully(sessionId, inStr);
/*
* Find out which ciphersuite the server has
* choosen. If we don't support this ciphersuite,
* the TlsCipherSuiteManager will throw an
* exception.
*/
this.choosenCipherSuite = TlsCipherSuiteManager.GetCipherSuite(
TlsUtilities.ReadUint16(inStr), this);
/*
* We support only the null compression which
* means no compression.
*/
short compressionMethod = TlsUtilities.ReadUint8(inStr);
if (compressionMethod != 0)
{
this.FailWithError(TlsProtocolHandler.AL_fatal, TlsProtocolHandler.AP_illegal_parameter);
}
AssertEmpty(inStr);
connection_state = CS_SERVER_HELLO_RECEIVED;
read = true;
break;
default:
this.FailWithError(AL_fatal, AP_unexpected_message);
break;
}
break;
case HP_SERVER_HELLO_DONE:
switch (connection_state)
{
case CS_SERVER_CERTIFICATE_RECEIVED:
case CS_SERVER_KEY_EXCHANGE_RECEIVED:
// NB: Original code used case label fall-through
if (connection_state == CS_SERVER_CERTIFICATE_RECEIVED)
{
/*
* There was no server key exchange message, check
* that we are doing RSA key exchange.
*/
if (this.choosenCipherSuite.KeyExchangeAlgorithm != TlsCipherSuite.KE_RSA)
{
this.FailWithError(AL_fatal, AP_unexpected_message);
}
}
AssertEmpty(inStr);
connection_state = CS_SERVER_HELLO_DONE_RECEIVED;
/*
* Send the client key exchange message, depending
* on the key exchange we are using in our
* ciphersuite.
*/
short ke = this.choosenCipherSuite.KeyExchangeAlgorithm;
switch (ke)
{
case TlsCipherSuite.KE_RSA:
/*
* We are doing RSA key exchange. We will
* choose a pre master secret and send it
* rsa encrypted to the server.
*
* Prepare pre master secret.
*/
pms = new byte[48];
pms[0] = 3;
pms[1] = 1;
random.NextBytes(pms, 2, 46);
/*
* Encode the pms and send it to the server.
*
* Prepare an Pkcs1Encoding with good random
* padding.
*/
RsaBlindedEngine rsa = new RsaBlindedEngine();
Pkcs1Encoding encoding = new Pkcs1Encoding(rsa);
encoding.Init(true, new ParametersWithRandom(this.serverRsaKey, this.random));
byte[] encrypted = null;
try
{
encrypted = encoding.ProcessBlock(pms, 0, pms.Length);
}
catch (InvalidCipherTextException)
{
/*
* This should never happen, only during decryption.
*/
this.FailWithError(AL_fatal, AP_internal_error);
}
/*
* Send the encrypted pms.
*/
MemoryStream bos = new MemoryStream();
TlsUtilities.WriteUint8(HP_CLIENT_KEY_EXCHANGE, bos);
TlsUtilities.WriteUint24(encrypted.Length + 2, bos);
TlsUtilities.WriteUint16(encrypted.Length, bos);
bos.Write(encrypted, 0, encrypted.Length);
byte[] message = bos.ToArray();
rs.WriteMessage((short)RL_HANDSHAKE, message, 0, message.Length);
break;
case TlsCipherSuite.KE_DHE_RSA:
/*
* Send the Client Key Exchange message for
* DHE key exchange.
*/
byte[] YcByte = this.Yc.ToByteArray();
MemoryStream DHbos = new MemoryStream();
TlsUtilities.WriteUint8(HP_CLIENT_KEY_EXCHANGE, DHbos);
TlsUtilities.WriteUint24(YcByte.Length + 2, DHbos);
TlsUtilities.WriteUint16(YcByte.Length, DHbos);
DHbos.Write(YcByte, 0, YcByte.Length);
byte[] DHmessage = DHbos.ToArray();
rs.WriteMessage((short)RL_HANDSHAKE, DHmessage, 0, DHmessage.Length);
break;
default:
/*
* Proble during handshake, we don't know
* how to thandle this key exchange method.
*/
this.FailWithError(AL_fatal, AP_unexpected_message);
break;
}
connection_state = CS_CLIENT_KEY_EXCHANGE_SEND;
/*
* Now, we send change cipher state
*/
byte[] cmessage = new byte[1];
cmessage[0] = 1;
rs.WriteMessage((short)RL_CHANGE_CIPHER_SPEC, cmessage, 0, cmessage.Length);
connection_state = CS_CLIENT_CHANGE_CIPHER_SPEC_SEND;
/*
* Calculate the ms
*/
this.ms = new byte[48];
byte[] randBytes = new byte[clientRandom.Length + serverRandom.Length];
Array.Copy(clientRandom, 0, randBytes, 0, clientRandom.Length);
Array.Copy(serverRandom, 0, randBytes, clientRandom.Length, serverRandom.Length);
TlsUtilities.PRF(pms, TlsUtilities.ToByteArray("master secret"), randBytes, this.ms);
/*
* Initialize our cipher suite
*/
rs.writeSuite = this.choosenCipherSuite;
rs.writeSuite.Init(this.ms, clientRandom, serverRandom);
/*
* Send our finished message.
*/
byte[] checksum = new byte[12];
byte[] md5andsha1 = new byte[16 + 20];
rs.hash1.DoFinal(md5andsha1, 0);
TlsUtilities.PRF(this.ms, TlsUtilities.ToByteArray("client finished"), md5andsha1, checksum);
MemoryStream bos2 = new MemoryStream();
TlsUtilities.WriteUint8(HP_FINISHED, bos2);
TlsUtilities.WriteUint24(12, bos2);
bos2.Write(checksum, 0, checksum.Length);
byte[] message2 = bos2.ToArray();
rs.WriteMessage((short)RL_HANDSHAKE, message2, 0, message2.Length);
this.connection_state = CS_CLIENT_FINISHED_SEND;
read = true;
break;
default:
this.FailWithError(AL_fatal, AP_handshake_failure);
break;
}
break;
case HP_SERVER_KEY_EXCHANGE:
switch (connection_state)
{
case CS_SERVER_CERTIFICATE_RECEIVED:
/*
* Check that we are doing DHE key exchange
*/
if (this.choosenCipherSuite.KeyExchangeAlgorithm != TlsCipherSuite.KE_DHE_RSA)
{
this.FailWithError(AL_fatal, AP_unexpected_message);
}
/*
* Parse the Structure
*/
int pLength = TlsUtilities.ReadUint16(inStr);
byte[] pByte = new byte[pLength];
TlsUtilities.ReadFully(pByte, inStr);
int gLength = TlsUtilities.ReadUint16(inStr);
byte[] gByte = new byte[gLength];
TlsUtilities.ReadFully(gByte, inStr);
int YsLength = TlsUtilities.ReadUint16(inStr);
byte[] YsByte = new byte[YsLength];
TlsUtilities.ReadFully(YsByte, inStr);
int sigLength = TlsUtilities.ReadUint16(inStr);
byte[] sigByte = new byte[sigLength];
TlsUtilities.ReadFully(sigByte, inStr);
this.AssertEmpty(inStr);
/*
* Verify the Signature.
*
* First, calculate the hash.
*/
CombinedHash sigDigest = new CombinedHash();
MemoryStream signedData = new MemoryStream();
TlsUtilities.WriteUint16(pLength, signedData);
signedData.Write(pByte, 0, pByte.Length);
TlsUtilities.WriteUint16(gLength, signedData);
signedData.Write(gByte, 0, gByte.Length);
TlsUtilities.WriteUint16(YsLength, signedData);
signedData.Write(YsByte, 0, YsByte.Length);
byte[] signed = signedData.ToArray();
sigDigest.BlockUpdate(this.clientRandom, 0, this.clientRandom.Length);
sigDigest.BlockUpdate(this.serverRandom, 0, this.serverRandom.Length);
sigDigest.BlockUpdate(signed, 0, signed.Length);
byte[] hash = new byte[sigDigest.GetDigestSize()];
sigDigest.DoFinal(hash, 0);
/*
* Now, do the RSA operation
*/
RsaBlindedEngine rsa = new RsaBlindedEngine();
Pkcs1Encoding encoding = new Pkcs1Encoding(rsa);
encoding.Init(false, this.serverRsaKey);
/*
* The data which was signed
*/
byte[] sigHash = null;
try
{
sigHash = encoding.ProcessBlock(sigByte, 0, sigByte.Length);
}
catch (InvalidCipherTextException)
{
this.FailWithError(AL_fatal, AP_bad_certificate);
}
/*
* Check if the data which was signed is equal to
* the hash we calculated.
*/
if (sigHash.Length != hash.Length)
{
this.FailWithError(AL_fatal, AP_bad_certificate);
}
for (int i = 0; i < sigHash.Length; i++)
{
if (sigHash[i] != hash[i])
{
this.FailWithError(AL_fatal, AP_bad_certificate);
}
}
/*
* OK, Signature was correct.
*
* Do the DH calculation.
*/
BigInteger p = new BigInteger(1, pByte);
BigInteger g = new BigInteger(1, gByte);
BigInteger Ys = new BigInteger(1, YsByte);
BigInteger x = new BigInteger(p.BitLength - 1, this.random);
Yc = g.ModPow(x, p);
this.pms = (Ys.ModPow(x, p)).ToByteArray();
/*
* Remove leading zero byte, if present.
*/
if (this.pms[0] == 0)
{
byte[] tmp = new byte[this.pms.Length - 1];
Array.Copy(this.pms, 1, tmp, 0, tmp.Length);
this.pms = tmp;
}
this.connection_state = CS_SERVER_KEY_EXCHANGE_RECEIVED;
read = true;
break;
default:
this.FailWithError(AL_fatal, AP_unexpected_message);
break;
}
break;
case HP_HELLO_REQUEST:
case HP_CLIENT_KEY_EXCHANGE:
case HP_CERTIFICATE_REQUEST:
case HP_CERTIFICATE_VERIFY:
case HP_CLIENT_HELLO:
default:
// We do not support this!
this.FailWithError(AL_fatal, AP_unexpected_message);
break;
}
}
}
}
while (read);
}
private void processHandshake()
{
bool read;
do
{
read = false;
/*
* We need the first 4 bytes, they contain type and length of
* the message.
*/
if (handshakeQueue.Available >= 4)
{
byte[] beginning = new byte[4];
handshakeQueue.Read(beginning, 0, 4, 0);
MemoryStream bis = new MemoryStream(beginning, false);
short type = TlsUtilities.ReadUint8(bis);
int len = TlsUtilities.ReadUint24(bis);
/*
* Check if we have enough bytes in the buffer to read
* the full message.
*/
if (handshakeQueue.Available >= (len + 4))
{
/*
* Read the message.
*/
byte[] buf = new byte[len];
handshakeQueue.Read(buf, 0, len, 4);
handshakeQueue.RemoveData(len + 4);
/*
* If it is not a finished message, update our hashes
* we prepare for the finish message.
*/
if (type != HP_FINISHED)
{
rs.hash1.BlockUpdate(beginning, 0, 4);
rs.hash2.BlockUpdate(beginning, 0, 4);
rs.hash1.BlockUpdate(buf, 0, len);
rs.hash2.BlockUpdate(buf, 0, len);
}
/*
* Now, parse the message.
*/
MemoryStream inStr = new MemoryStream(buf, false);
/*
* Check the type.
*/
switch (type)
{
case HP_CERTIFICATE:
{
switch (connection_state)
{
case CS_SERVER_HELLO_RECEIVED:
{
/*
* Parse the certificates.
*/
Certificate cert = Certificate.Parse(inStr);
AssertEmpty(inStr);
X509CertificateStructure x509Cert = cert.certs[0];
SubjectPublicKeyInfo keyInfo = x509Cert.SubjectPublicKeyInfo;
try
{
this.serverPublicKey = PublicKeyFactory.CreateKey(keyInfo);
}
catch (Exception)
{
this.FailWithError(AL_fatal, AP_unsupported_certificate);
}
// Sanity check the PublicKeyFactory
if (this.serverPublicKey.IsPrivate)
{
this.FailWithError(AL_fatal, AP_internal_error);
}
/*
* Perform various checks per RFC2246 7.4.2
* TODO "Unless otherwise specified, the signing algorithm for the certificate
* must be the same as the algorithm for the certificate key."
*/
switch (this.chosenCipherSuite.KeyExchangeAlgorithm)
{
case TlsCipherSuite.KE_RSA:
if (!(this.serverPublicKey is RsaKeyParameters))
{
this.FailWithError(AL_fatal, AP_certificate_unknown);
}
validateKeyUsage(x509Cert, KeyUsage.KeyEncipherment);
break;
case TlsCipherSuite.KE_DHE_RSA:
case TlsCipherSuite.KE_SRP_RSA:
if (!(this.serverPublicKey is RsaKeyParameters))
{
this.FailWithError(AL_fatal, AP_certificate_unknown);
}
validateKeyUsage(x509Cert, KeyUsage.DigitalSignature);
break;
case TlsCipherSuite.KE_DHE_DSS:
case TlsCipherSuite.KE_SRP_DSS:
if (!(this.serverPublicKey is DsaPublicKeyParameters))
{
this.FailWithError(AL_fatal, AP_certificate_unknown);
}
break;
default:
this.FailWithError(AL_fatal, AP_unsupported_certificate);
break;
}
/*
* Verify them.
*/
if (!this.verifyer.IsValid(cert.GetCerts()))
{
this.FailWithError(AL_fatal, AP_user_canceled);
}
break;
}
default:
this.FailWithError(AL_fatal, AP_unexpected_message);
break;
}
connection_state = CS_SERVER_CERTIFICATE_RECEIVED;
read = true;
break;
}
case HP_FINISHED:
switch (connection_state)
{
case CS_SERVER_CHANGE_CIPHER_SPEC_RECEIVED:
/*
* Read the checksum from the finished message,
* it has always 12 bytes.
*/
byte[] receivedChecksum = new byte[12];
TlsUtilities.ReadFully(receivedChecksum, inStr);
AssertEmpty(inStr);
/*
* Calculate our own checksum.
*/
byte[] checksum = new byte[12];
byte[] md5andsha1 = new byte[16 + 20];
rs.hash2.DoFinal(md5andsha1, 0);
TlsUtilities.PRF(this.ms, TlsUtilities.ToByteArray("server finished"), md5andsha1, checksum);
/*
* Compare both checksums.
*/
for (int i = 0; i < receivedChecksum.Length; i++)
{
if (receivedChecksum[i] != checksum[i])
{
/*
* Wrong checksum in the finished message.
*/
this.FailWithError(AL_fatal, AP_handshake_failure);
}
}
connection_state = CS_DONE;
/*
* We are now ready to receive application data.
*/
this.appDataReady = true;
read = true;
break;
default:
this.FailWithError(AL_fatal, AP_unexpected_message);
break;
}
break;
case HP_SERVER_HELLO:
switch (connection_state)
{
case CS_CLIENT_HELLO_SEND:
/*
* Read the server hello message
*/
TlsUtilities.CheckVersion(inStr, this);
/*
* Read the server random
*/
this.serverRandom = new byte[32];
TlsUtilities.ReadFully(this.serverRandom, inStr);
/*
* Currently, we don't support session ids
*/
byte[] sessionId = TlsUtilities.ReadOpaque8(inStr);
/*
* Find out which ciphersuite the server has
* chosen. If we don't support this ciphersuite,
* the TlsCipherSuiteManager will throw an
* exception.
*/
this.chosenCipherSuite = TlsCipherSuiteManager.GetCipherSuite(
TlsUtilities.ReadUint16(inStr), this);
/*
* We support only the null compression which
* means no compression.
*/
short compressionMethod = TlsUtilities.ReadUint8(inStr);
if (compressionMethod != 0)
{
this.FailWithError(TlsProtocolHandler.AL_fatal, TlsProtocolHandler.AP_illegal_parameter);
}
/*
* RFC4366 2.2
* The extended server hello message format MAY be sent
* in place of the server hello message when the client
* has requested extended functionality via the extended
* client hello message specified in Section 2.1.
*/
if (extendedClientHello && inStr.Position < inStr.Length)
{
// Process extensions from extended server hello
byte[] extBytes = TlsUtilities.ReadOpaque16(inStr);
// Int32 -> byte[]
Hashtable serverExtensions = new Hashtable();
MemoryStream ext = new MemoryStream(extBytes, false);
while (ext.Position < ext.Length)
{
int extType = TlsUtilities.ReadUint16(ext);
byte[] extValue = TlsUtilities.ReadOpaque16(ext);
serverExtensions[extType] = extValue;
}
// TODO Validate/process serverExtensions (via client?)
// TODO[SRP]
}
/*
* Process any extensions
*/
// TODO[SRP]
// if (inStr.Position < inStr.Length)
// {
// int extensionsLength = TlsUtilities.ReadUint16(inStr);
// byte[] extensions = new byte[extensionsLength];
// TlsUtilities.ReadFully(extensions, inStr);
//
// // TODO Validate/process
// }
AssertEmpty(inStr);
connection_state = CS_SERVER_HELLO_RECEIVED;
read = true;
break;
default:
this.FailWithError(AL_fatal, AP_unexpected_message);
break;
}
break;
case HP_SERVER_HELLO_DONE:
switch (connection_state)
{
case CS_SERVER_CERTIFICATE_RECEIVED:
case CS_SERVER_KEY_EXCHANGE_RECEIVED:
case CS_CERTIFICATE_REQUEST_RECEIVED:
// NB: Original code used case label fall-through
if (connection_state == CS_SERVER_CERTIFICATE_RECEIVED)
{
/*
* There was no server key exchange message, check
* that we are doing RSA key exchange.
*/
if (this.chosenCipherSuite.KeyExchangeAlgorithm != TlsCipherSuite.KE_RSA)
{
this.FailWithError(AL_fatal, AP_unexpected_message);
}
}
AssertEmpty(inStr);
bool isCertReq = (connection_state == CS_CERTIFICATE_REQUEST_RECEIVED);
connection_state = CS_SERVER_HELLO_DONE_RECEIVED;
if (isCertReq)
{
sendClientCertificate();
}
/*
* Send the client key exchange message, depending
* on the key exchange we are using in our
* ciphersuite.
*/
switch (this.chosenCipherSuite.KeyExchangeAlgorithm)
{
case TlsCipherSuite.KE_RSA:
{
/*
* We are doing RSA key exchange. We will
* choose a pre master secret and send it
* rsa encrypted to the server.
*
* Prepare pre master secret.
*/
pms = new byte[48];
pms[0] = 3;
pms[1] = 1;
random.NextBytes(pms, 2, 46);
/*
* Encode the pms and send it to the server.
*
* Prepare an Pkcs1Encoding with good random
* padding.
*/
RsaBlindedEngine rsa = new RsaBlindedEngine();
Pkcs1Encoding encoding = new Pkcs1Encoding(rsa);
encoding.Init(true, new ParametersWithRandom(this.serverPublicKey, this.random));
byte[] encrypted = null;
try
{
encrypted = encoding.ProcessBlock(pms, 0, pms.Length);
}
catch (InvalidCipherTextException)
{
/*
* This should never happen, only during decryption.
*/
this.FailWithError(AL_fatal, AP_internal_error);
}
/*
* Send the encrypted pms.
*/
sendClientKeyExchange(encrypted);
break;
}
case TlsCipherSuite.KE_DHE_DSS:
case TlsCipherSuite.KE_DHE_RSA:
{
/*
* Send the Client Key Exchange message for
* DHE key exchange.
*/
byte[] YcByte = BigIntegers.AsUnsignedByteArray(this.Yc);
sendClientKeyExchange(YcByte);
break;
}
case TlsCipherSuite.KE_SRP:
case TlsCipherSuite.KE_SRP_RSA:
case TlsCipherSuite.KE_SRP_DSS:
{
/*
* Send the Client Key Exchange message for
* SRP key exchange.
*/
byte[] bytes = BigIntegers.AsUnsignedByteArray(this.SRP_A);
sendClientKeyExchange(bytes);
break;
}
default:
/*
* Problem during handshake, we don't know
* how to handle this key exchange method.
*/
this.FailWithError(AL_fatal, AP_unexpected_message);
break;
}
connection_state = CS_CLIENT_KEY_EXCHANGE_SEND;
/*
* Now, we send change cipher state
*/
byte[] cmessage = new byte[1];
cmessage[0] = 1;
rs.WriteMessage((short)RL_CHANGE_CIPHER_SPEC, cmessage, 0, cmessage.Length);
connection_state = CS_CLIENT_CHANGE_CIPHER_SPEC_SEND;
/*
* Calculate the ms
*/
this.ms = new byte[48];
byte[] randBytes = new byte[clientRandom.Length + serverRandom.Length];
Array.Copy(clientRandom, 0, randBytes, 0, clientRandom.Length);
Array.Copy(serverRandom, 0, randBytes, clientRandom.Length, serverRandom.Length);
TlsUtilities.PRF(pms, TlsUtilities.ToByteArray("master secret"), randBytes, this.ms);
/*
* Initialize our cipher suite
*/
rs.writeSuite = this.chosenCipherSuite;
rs.writeSuite.Init(this.ms, clientRandom, serverRandom);
/*
* Send our finished message.
*/
byte[] checksum = new byte[12];
byte[] md5andsha1 = new byte[16 + 20];
rs.hash1.DoFinal(md5andsha1, 0);
TlsUtilities.PRF(this.ms, TlsUtilities.ToByteArray("client finished"), md5andsha1, checksum);
MemoryStream bos2 = new MemoryStream();
TlsUtilities.WriteUint8(HP_FINISHED, bos2);
TlsUtilities.WriteUint24(12, bos2);
bos2.Write(checksum, 0, checksum.Length);
byte[] message2 = bos2.ToArray();
rs.WriteMessage((short)RL_HANDSHAKE, message2, 0, message2.Length);
this.connection_state = CS_CLIENT_FINISHED_SEND;
read = true;
break;
default:
this.FailWithError(AL_fatal, AP_handshake_failure);
break;
}
break;
case HP_SERVER_KEY_EXCHANGE:
{
switch (connection_state)
{
case CS_SERVER_HELLO_RECEIVED:
case CS_SERVER_CERTIFICATE_RECEIVED:
{
// NB: Original code used case label fall-through
if (connection_state == CS_SERVER_HELLO_RECEIVED)
{
/*
* There was no server certificate message, check
* that we are doing SRP key exchange.
*/
if (this.chosenCipherSuite.KeyExchangeAlgorithm != TlsCipherSuite.KE_SRP)
{
this.FailWithError(AL_fatal, AP_unexpected_message);
}
}
/*
* Check that we are doing DHE key exchange
*/
switch (this.chosenCipherSuite.KeyExchangeAlgorithm)
{
case TlsCipherSuite.KE_DHE_RSA:
{
processDHEKeyExchange(inStr, new TlsRsaSigner());
break;
}
case TlsCipherSuite.KE_DHE_DSS:
{
processDHEKeyExchange(inStr, new TlsDssSigner());
break;
}
case TlsCipherSuite.KE_SRP:
{
processSRPKeyExchange(inStr, null);
break;
}
case TlsCipherSuite.KE_SRP_RSA:
{
processSRPKeyExchange(inStr, new TlsRsaSigner());
break;
}
case TlsCipherSuite.KE_SRP_DSS:
{
processSRPKeyExchange(inStr, new TlsDssSigner());
break;
}
default:
this.FailWithError(AL_fatal, AP_unexpected_message);
break;
}
break;
}
default:
this.FailWithError(AL_fatal, AP_unexpected_message);
break;
}
this.connection_state = CS_SERVER_KEY_EXCHANGE_RECEIVED;
read = true;
break;
}
case HP_CERTIFICATE_REQUEST:
switch (connection_state)
{
case CS_SERVER_CERTIFICATE_RECEIVED:
case CS_SERVER_KEY_EXCHANGE_RECEIVED:
{
// NB: Original code used case label fall-through
if (connection_state == CS_SERVER_CERTIFICATE_RECEIVED)
{
/*
* There was no server key exchange message, check
* that we are doing RSA key exchange.
*/
if (this.chosenCipherSuite.KeyExchangeAlgorithm != TlsCipherSuite.KE_RSA)
{
this.FailWithError(AL_fatal, AP_unexpected_message);
}
}
byte[] types = TlsUtilities.ReadOpaque8(inStr);
byte[] auths = TlsUtilities.ReadOpaque8(inStr);
// TODO Validate/process
AssertEmpty(inStr);
break;
}
default:
this.FailWithError(AL_fatal, AP_unexpected_message);
break;
}
this.connection_state = CS_CERTIFICATE_REQUEST_RECEIVED;
read = true;
break;
case HP_HELLO_REQUEST:
case HP_CLIENT_KEY_EXCHANGE:
case HP_CERTIFICATE_VERIFY:
case HP_CLIENT_HELLO:
default:
// We do not support this!
this.FailWithError(AL_fatal, AP_unexpected_message);
break;
}
}
}
}
while (read);
}
private void processHandshake()
{
bool read;
do
{
read = false;
/*
* We need the first 4 bytes, they contain type and length of
* the message.
*/
if (handshakeQueue.Available >= 4)
{
byte[] beginning = new byte[4];
handshakeQueue.Read(beginning, 0, 4, 0);
MemoryStream bis = new MemoryStream(beginning, false);
short type = TlsUtilities.ReadUint8(bis);
int len = TlsUtilities.ReadUint24(bis);
/*
* Check if we have enough bytes in the buffer to read
* the full message.
*/
if (handshakeQueue.Available >= (len + 4))
{
/*
* Read the message.
*/
byte[] buf = new byte[len];
handshakeQueue.Read(buf, 0, len, 4);
handshakeQueue.RemoveData(len + 4);
/*
* If it is not a finished message, update our hashes
* we prepare for the finish message.
*/
if (type != HP_FINISHED)
{
rs.hash1.BlockUpdate(beginning, 0, 4);
rs.hash2.BlockUpdate(beginning, 0, 4);
rs.hash1.BlockUpdate(buf, 0, len);
rs.hash2.BlockUpdate(buf, 0, len);
}
/*
* Now, parse the message.
*/
MemoryStream inStr = new MemoryStream(buf, false);
/*
* Check the type.
*/
switch (type)
{
case HP_CERTIFICATE:
switch (connection_state)
{
case CS_SERVER_HELLO_RECEIVED:
/*
* Parse the certificates.
*/
Certificate cert = Certificate.Parse(inStr);
AssertEmpty(inStr);
/*
* Verify them.
*/
if (!this.verifyer.IsValid(cert.GetCerts()))
{
this.FailWithError(AL_fatal, AP_user_canceled);
}
/*
* We only support RSA certificates. Lets hope
* this is one.
*/
RsaPublicKeyStructure rsaKey = null;
try
{
rsaKey = RsaPublicKeyStructure.GetInstance(
cert.certs[0].TbsCertificate.SubjectPublicKeyInfo.GetPublicKey());
}
catch (Exception)
{
/*
* Sorry, we have to fail ;-(
*/
this.FailWithError(AL_fatal, AP_unsupported_certificate);
}
/*
* Parse the servers public RSA key.
*/
this.serverRsaKey = new RsaKeyParameters(
false,
rsaKey.Modulus,
rsaKey.PublicExponent);
connection_state = CS_SERVER_CERTIFICATE_RECEIVED;
read = true;
break;
default:
this.FailWithError(AL_fatal, AP_unexpected_message);
break;
}
break;
case HP_FINISHED:
switch (connection_state)
{
case CS_SERVER_CHANGE_CIPHER_SPEC_RECEIVED:
/*
* Read the checksum from the finished message,
* it has always 12 bytes.
*/
byte[] receivedChecksum = new byte[12];
TlsUtilities.ReadFully(receivedChecksum, inStr);
AssertEmpty(inStr);
/*
* Calculate our owne checksum.
*/
byte[] checksum = new byte[12];
byte[] md5andsha1 = new byte[16 + 20];
rs.hash2.DoFinal(md5andsha1, 0);
TlsUtilities.PRF(this.ms, TlsUtilities.ToByteArray("server finished"), md5andsha1, checksum);
/*
* Compare both checksums.
*/
for (int i = 0; i < receivedChecksum.Length; i++)
{
if (receivedChecksum[i] != checksum[i])
{
/*
* Wrong checksum in the finished message.
*/
this.FailWithError(AL_fatal, AP_handshake_failure);
}
}
connection_state = CS_DONE;
/*
* We are now ready to receive application data.
*/
this.appDataReady = true;
read = true;
break;
default:
this.FailWithError(AL_fatal, AP_unexpected_message);
break;
}
break;
case HP_SERVER_HELLO:
switch (connection_state)
{
case CS_CLIENT_HELLO_SEND:
/*
* Read the server hello message
*/
TlsUtilities.CheckVersion(inStr, this);
/*
* Read the server random
*/
this.serverRandom = new byte[32];
TlsUtilities.ReadFully(this.serverRandom, inStr);
/*
* Currenty, we don't support session ids
*/
short sessionIdLength = TlsUtilities.ReadUint8(inStr);
byte[] sessionId = new byte[sessionIdLength];
TlsUtilities.ReadFully(sessionId, inStr);
/*
* Find out which ciphersuite the server has
* choosen. If we don't support this ciphersuite,
* the TlsCipherSuiteManager will throw an
* exception.
*/
this.choosenCipherSuite = TlsCipherSuiteManager.GetCipherSuite(
TlsUtilities.ReadUint16(inStr), this);
/*
* We support only the null compression which
* means no compression.
*/
short compressionMethod = TlsUtilities.ReadUint8(inStr);
if (compressionMethod != 0)
{
this.FailWithError(TlsProtocolHandler.AL_fatal, TlsProtocolHandler.AP_illegal_parameter);
}
AssertEmpty(inStr);
connection_state = CS_SERVER_HELLO_RECEIVED;
read = true;
break;
default:
this.FailWithError(AL_fatal, AP_unexpected_message);
break;
}
break;
case HP_SERVER_HELLO_DONE:
switch (connection_state)
{
case CS_SERVER_CERTIFICATE_RECEIVED:
case CS_SERVER_KEY_EXCHANGE_RECEIVED:
// NB: Original code used case label fall-through
if (connection_state == CS_SERVER_CERTIFICATE_RECEIVED)
{
/*
* There was no server key exchange message, check
* that we are doing RSA key exchange.
*/
if (this.choosenCipherSuite.KeyExchangeAlgorithm != TlsCipherSuite.KE_RSA)
{
this.FailWithError(AL_fatal, AP_unexpected_message);
}
}
AssertEmpty(inStr);
connection_state = CS_SERVER_HELLO_DONE_RECEIVED;
/*
* Send the client key exchange message, depending
* on the key exchange we are using in our
* ciphersuite.
*/
short ke = this.choosenCipherSuite.KeyExchangeAlgorithm;
switch (ke)
{
case TlsCipherSuite.KE_RSA:
/*
* We are doing RSA key exchange. We will
* choose a pre master secret and send it
* rsa encrypted to the server.
*
* Prepare pre master secret.
*/
pms = new byte[48];
pms[0] = 3;
pms[1] = 1;
random.NextBytes(pms, 2, 46);
/*
* Encode the pms and send it to the server.
*
* Prepare an Pkcs1Encoding with good random
* padding.
*/
RsaBlindedEngine rsa = new RsaBlindedEngine();
Pkcs1Encoding encoding = new Pkcs1Encoding(rsa);
encoding.Init(true, new ParametersWithRandom(this.serverRsaKey, this.random));
byte[] encrypted = null;
try
{
encrypted = encoding.ProcessBlock(pms, 0, pms.Length);
}
catch (InvalidCipherTextException)
{
/*
* This should never happen, only during decryption.
*/
this.FailWithError(AL_fatal, AP_internal_error);
}
/*
* Send the encrypted pms.
*/
MemoryStream bos = new MemoryStream();
TlsUtilities.WriteUint8(HP_CLIENT_KEY_EXCHANGE, bos);
TlsUtilities.WriteUint24(encrypted.Length + 2, bos);
TlsUtilities.WriteUint16(encrypted.Length, bos);
bos.Write(encrypted, 0, encrypted.Length);
byte[] message = bos.ToArray();
rs.WriteMessage((short)RL_HANDSHAKE, message, 0, message.Length);
break;
case TlsCipherSuite.KE_DHE_RSA:
/*
* Send the Client Key Exchange message for
* DHE key exchange.
*/
byte[] YcByte = this.Yc.ToByteArray();
MemoryStream DHbos = new MemoryStream();
TlsUtilities.WriteUint8(HP_CLIENT_KEY_EXCHANGE, DHbos);
TlsUtilities.WriteUint24(YcByte.Length + 2, DHbos);
TlsUtilities.WriteUint16(YcByte.Length, DHbos);
DHbos.Write(YcByte, 0, YcByte.Length);
byte[] DHmessage = DHbos.ToArray();
rs.WriteMessage((short)RL_HANDSHAKE, DHmessage, 0, DHmessage.Length);
break;
default:
/*
* Proble during handshake, we don't know
* how to thandle this key exchange method.
*/
this.FailWithError(AL_fatal, AP_unexpected_message);
break;
}
connection_state = CS_CLIENT_KEY_EXCHANGE_SEND;
/*
* Now, we send change cipher state
*/
byte[] cmessage = new byte[1];
cmessage[0] = 1;
rs.WriteMessage((short)RL_CHANGE_CIPHER_SPEC, cmessage, 0, cmessage.Length);
connection_state = CS_CLIENT_CHANGE_CIPHER_SPEC_SEND;
/*
* Calculate the ms
*/
this.ms = new byte[48];
byte[] randBytes = new byte[clientRandom.Length + serverRandom.Length];
Array.Copy(clientRandom, 0, randBytes, 0, clientRandom.Length);
Array.Copy(serverRandom, 0, randBytes, clientRandom.Length, serverRandom.Length);
TlsUtilities.PRF(pms, TlsUtilities.ToByteArray("master secret"), randBytes, this.ms);
/*
* Initialize our cipher suite
*/
rs.writeSuite = this.choosenCipherSuite;
rs.writeSuite.Init(this.ms, clientRandom, serverRandom);
/*
* Send our finished message.
*/
byte[] checksum = new byte[12];
byte[] md5andsha1 = new byte[16 + 20];
rs.hash1.DoFinal(md5andsha1, 0);
TlsUtilities.PRF(this.ms, TlsUtilities.ToByteArray("client finished"), md5andsha1, checksum);
MemoryStream bos2 = new MemoryStream();
TlsUtilities.WriteUint8(HP_FINISHED, bos2);
TlsUtilities.WriteUint24(12, bos2);
bos2.Write(checksum, 0, checksum.Length);
byte[] message2 = bos2.ToArray();
rs.WriteMessage((short)RL_HANDSHAKE, message2, 0, message2.Length);
this.connection_state = CS_CLIENT_FINISHED_SEND;
read = true;
break;
default:
this.FailWithError(AL_fatal, AP_handshake_failure);
break;
}
break;
case HP_SERVER_KEY_EXCHANGE:
switch (connection_state)
{
case CS_SERVER_CERTIFICATE_RECEIVED:
/*
* Check that we are doing DHE key exchange
*/
if (this.choosenCipherSuite.KeyExchangeAlgorithm != TlsCipherSuite.KE_DHE_RSA)
{
this.FailWithError(AL_fatal, AP_unexpected_message);
}
/*
* Parse the Structure
*/
int pLength = TlsUtilities.ReadUint16(inStr);
byte[] pByte = new byte[pLength];
TlsUtilities.ReadFully(pByte, inStr);
int gLength = TlsUtilities.ReadUint16(inStr);
byte[] gByte = new byte[gLength];
TlsUtilities.ReadFully(gByte, inStr);
int YsLength = TlsUtilities.ReadUint16(inStr);
byte[] YsByte = new byte[YsLength];
TlsUtilities.ReadFully(YsByte, inStr);
int sigLength = TlsUtilities.ReadUint16(inStr);
byte[] sigByte = new byte[sigLength];
TlsUtilities.ReadFully(sigByte, inStr);
this.AssertEmpty(inStr);
/*
* Verify the Signature.
*
* First, calculate the hash.
*/
CombinedHash sigDigest = new CombinedHash();
MemoryStream signedData = new MemoryStream();
TlsUtilities.WriteUint16(pLength, signedData);
signedData.Write(pByte, 0, pByte.Length);
TlsUtilities.WriteUint16(gLength, signedData);
signedData.Write(gByte, 0, gByte.Length);
TlsUtilities.WriteUint16(YsLength, signedData);
signedData.Write(YsByte, 0, YsByte.Length);
byte[] signed = signedData.ToArray();
sigDigest.BlockUpdate(this.clientRandom, 0, this.clientRandom.Length);
sigDigest.BlockUpdate(this.serverRandom, 0, this.serverRandom.Length);
sigDigest.BlockUpdate(signed, 0, signed.Length);
byte[] hash = new byte[sigDigest.GetDigestSize()];
sigDigest.DoFinal(hash, 0);
/*
* Now, do the RSA operation
*/
RsaBlindedEngine rsa = new RsaBlindedEngine();
Pkcs1Encoding encoding = new Pkcs1Encoding(rsa);
encoding.Init(false, this.serverRsaKey);
/*
* The data which was signed
*/
byte[] sigHash = null;
try
{
sigHash = encoding.ProcessBlock(sigByte, 0, sigByte.Length);
}
catch (InvalidCipherTextException)
{
this.FailWithError(AL_fatal, AP_bad_certificate);
}
/*
* Check if the data which was signed is equal to
* the hash we calculated.
*/
if (sigHash.Length != hash.Length)
{
this.FailWithError(AL_fatal, AP_bad_certificate);
}
for (int i = 0; i < sigHash.Length; i++)
{
if (sigHash[i] != hash[i])
{
this.FailWithError(AL_fatal, AP_bad_certificate);
}
}
/*
* OK, Signature was correct.
*
* Do the DH calculation.
*/
BigInteger p = new BigInteger(1, pByte);
BigInteger g = new BigInteger(1, gByte);
BigInteger Ys = new BigInteger(1, YsByte);
BigInteger x = new BigInteger(p.BitLength - 1, this.random);
Yc = g.ModPow(x, p);
this.pms = (Ys.ModPow(x, p)).ToByteArray();
/*
* Remove leading zero byte, if present.
*/
if (this.pms[0] == 0)
{
byte[] tmp = new byte[this.pms.Length - 1];
Array.Copy(this.pms, 1, tmp, 0, tmp.Length);
this.pms = tmp;
}
this.connection_state = CS_SERVER_KEY_EXCHANGE_RECEIVED;
read = true;
break;
default:
this.FailWithError(AL_fatal, AP_unexpected_message);
break;
}
break;
case HP_HELLO_REQUEST:
case HP_CLIENT_KEY_EXCHANGE:
case HP_CERTIFICATE_REQUEST:
case HP_CERTIFICATE_VERIFY:
case HP_CLIENT_HELLO:
default:
// We do not support this!
this.FailWithError(AL_fatal, AP_unexpected_message);
break;
}
}
}
}while (read);
}