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author | dreijer <dreijer@echobit.net> | 2010-11-12 18:33:40 (GMT) |
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committer | Kevin Smith <git@kismith.co.uk> | 2011-11-03 18:49:22 (GMT) |
commit | 7b0795215f601a9561dbedbed3af32dbe9aba032 (patch) | |
tree | 554a6693de362fb3403a44a586f48865c4d949bf /Swiften/TLS/Schannel/SchannelContext.cpp | |
parent | 16d50c0df983e96a28a6572da27b3633b40a41d7 (diff) | |
download | swift-contrib-7b0795215f601a9561dbedbed3af32dbe9aba032.zip swift-contrib-7b0795215f601a9561dbedbed3af32dbe9aba032.tar.bz2 |
* Added Schannel support.
License: This patch is BSD-licensed, see http://www.opensource.org/licenses/bsd-license.php
Diffstat (limited to 'Swiften/TLS/Schannel/SchannelContext.cpp')
-rw-r--r-- | Swiften/TLS/Schannel/SchannelContext.cpp | 503 |
1 files changed, 503 insertions, 0 deletions
diff --git a/Swiften/TLS/Schannel/SchannelContext.cpp b/Swiften/TLS/Schannel/SchannelContext.cpp new file mode 100644 index 0000000..6771d4a --- /dev/null +++ b/Swiften/TLS/Schannel/SchannelContext.cpp @@ -0,0 +1,503 @@ +/* + * Copyright (c) 2011 Soren Dreijer + * Licensed under the simplified BSD license. + * See Documentation/Licenses/BSD-simplified.txt for more information. + */ + +#include "Swiften/TLS/Schannel/SchannelContext.h" +#include "Swiften/TLS/Schannel/SchannelCertificate.h" + +namespace Swift { + +//------------------------------------------------------------------------ + +SchannelContext::SchannelContext() +: m_state(Start) +, m_secContext(0) +, m_verificationError(CertificateVerificationError::UnknownError) +{ + m_ctxtFlags = ISC_REQ_ALLOCATE_MEMORY | + ISC_REQ_CONFIDENTIALITY | + ISC_REQ_EXTENDED_ERROR | + ISC_REQ_INTEGRITY | + ISC_REQ_REPLAY_DETECT | + ISC_REQ_SEQUENCE_DETECT | + ISC_REQ_USE_SUPPLIED_CREDS | + ISC_REQ_STREAM; + + ZeroMemory(&m_streamSizes, sizeof(m_streamSizes)); +} + +//------------------------------------------------------------------------ + +void SchannelContext::determineStreamSizes() +{ + QueryContextAttributes(m_ctxtHandle, SECPKG_ATTR_STREAM_SIZES, &m_streamSizes); +} + +//------------------------------------------------------------------------ + +void SchannelContext::connect() +{ + m_state = Connecting; + + // We use an empty list for client certificates + PCCERT_CONTEXT clientCerts[1] = {0}; + + SCHANNEL_CRED sc = {0}; + sc.dwVersion = SCHANNEL_CRED_VERSION; + sc.cCreds = 0; // Let Crypto API find the appropriate certificate for us + sc.paCred = clientCerts; + sc.grbitEnabledProtocols = SP_PROT_SSL3_CLIENT | SP_PROT_TLS1_CLIENT | SP_PROT_TLS1_1_CLIENT | SP_PROT_TLS1_2_CLIENT; + sc.dwFlags = SCH_CRED_AUTO_CRED_VALIDATION | /*SCH_CRED_NO_DEFAULT_CREDS*/ SCH_CRED_USE_DEFAULT_CREDS | SCH_CRED_REVOCATION_CHECK_CHAIN; + + // Swiften performs the server name check for us + sc.dwFlags |= SCH_CRED_NO_SERVERNAME_CHECK; + + SECURITY_STATUS status = AcquireCredentialsHandle( + NULL, + UNISP_NAME, + SECPKG_CRED_OUTBOUND, + NULL, + &sc, + NULL, + NULL, + m_credHandle.Reset(), + NULL); + + if (status != SEC_E_OK) + { + // We failed to obtain the credentials handle + indicateError(); + return; + } + + SecBuffer outBuffers[2]; + + // We let Schannel allocate the output buffer for us + outBuffers[0].pvBuffer = NULL; + outBuffers[0].cbBuffer = 0; + outBuffers[0].BufferType = SECBUFFER_TOKEN; + + // Contains alert data if an alert is generated + outBuffers[1].pvBuffer = NULL; + outBuffers[1].cbBuffer = 0; + outBuffers[1].BufferType = SECBUFFER_ALERT; + + // Make sure the output buffers are freed + ScopedSecBuffer scopedOutputData(&outBuffers[0]); + ScopedSecBuffer scopedOutputAlertData(&outBuffers[1]); + + SecBufferDesc outBufferDesc = {0}; + outBufferDesc.cBuffers = 2; + outBufferDesc.pBuffers = outBuffers; + outBufferDesc.ulVersion = SECBUFFER_VERSION; + + // Create the initial security context + status = InitializeSecurityContext( + m_credHandle, + NULL, + NULL, + m_ctxtFlags, + 0, + 0, + NULL, + 0, + m_ctxtHandle.Reset(), + &outBufferDesc, + &m_secContext, + NULL); + + if (status != SEC_E_OK && status != SEC_I_CONTINUE_NEEDED) + { + // We failed to initialize the security context + indicateError(); + return; + } + + // Start the handshake + sendDataOnNetwork(outBuffers[0].pvBuffer, outBuffers[0].cbBuffer); + + if (status == SEC_E_OK) + { + m_state = Connected; + determineStreamSizes(); + + onConnected(); + } +} + +//------------------------------------------------------------------------ + +void SchannelContext::appendNewData(const SafeByteArray& data) +{ + size_t originalSize = m_receivedData.size(); + m_receivedData.resize( originalSize + data.size() ); + memcpy( &m_receivedData[0] + originalSize, &data[0], data.size() ); +} + +//------------------------------------------------------------------------ + +void SchannelContext::continueHandshake(const SafeByteArray& data) +{ + appendNewData(data); + + while (!m_receivedData.empty()) + { + SecBuffer inBuffers[2]; + + // Provide Schannel with the remote host's handshake data + inBuffers[0].pvBuffer = (char*)(&m_receivedData[0]); + inBuffers[0].cbBuffer = (unsigned long)m_receivedData.size(); + inBuffers[0].BufferType = SECBUFFER_TOKEN; + + inBuffers[1].pvBuffer = NULL; + inBuffers[1].cbBuffer = 0; + inBuffers[1].BufferType = SECBUFFER_EMPTY; + + SecBufferDesc inBufferDesc = {0}; + inBufferDesc.cBuffers = 2; + inBufferDesc.pBuffers = inBuffers; + inBufferDesc.ulVersion = SECBUFFER_VERSION; + + SecBuffer outBuffers[2]; + + // We let Schannel allocate the output buffer for us + outBuffers[0].pvBuffer = NULL; + outBuffers[0].cbBuffer = 0; + outBuffers[0].BufferType = SECBUFFER_TOKEN; + + // Contains alert data if an alert is generated + outBuffers[1].pvBuffer = NULL; + outBuffers[1].cbBuffer = 0; + outBuffers[1].BufferType = SECBUFFER_ALERT; + + // Make sure the output buffers are freed + ScopedSecBuffer scopedOutputData(&outBuffers[0]); + ScopedSecBuffer scopedOutputAlertData(&outBuffers[1]); + + SecBufferDesc outBufferDesc = {0}; + outBufferDesc.cBuffers = 2; + outBufferDesc.pBuffers = outBuffers; + outBufferDesc.ulVersion = SECBUFFER_VERSION; + + SECURITY_STATUS status = InitializeSecurityContext( + m_credHandle, + m_ctxtHandle, + NULL, + m_ctxtFlags, + 0, + 0, + &inBufferDesc, + 0, + NULL, + &outBufferDesc, + &m_secContext, + NULL); + + if (status == SEC_E_INCOMPLETE_MESSAGE) + { + // Wait for more data to arrive + break; + } + else if (status == SEC_I_CONTINUE_NEEDED) + { + SecBuffer* pDataBuffer = &outBuffers[0]; + SecBuffer* pExtraBuffer = &inBuffers[1]; + + if (pDataBuffer && pDataBuffer->cbBuffer > 0 && pDataBuffer->pvBuffer != NULL) + sendDataOnNetwork(pDataBuffer->pvBuffer, pDataBuffer->cbBuffer); + + if (pExtraBuffer->BufferType == SECBUFFER_EXTRA) + m_receivedData.erase(m_receivedData.begin(), m_receivedData.end() - pExtraBuffer->cbBuffer); + else + m_receivedData.clear(); + + break; + } + else if (status == SEC_E_OK) + { + SecBuffer* pExtraBuffer = &inBuffers[1]; + + if (pExtraBuffer && pExtraBuffer->cbBuffer > 0) + m_receivedData.erase(m_receivedData.begin(), m_receivedData.end() - pExtraBuffer->cbBuffer); + else + m_receivedData.clear(); + + m_state = Connected; + determineStreamSizes(); + + onConnected(); + } + else + { + // We failed to initialize the security context + indicateError(); + return; + } + } +} + +//------------------------------------------------------------------------ + +void SchannelContext::sendDataOnNetwork(const void* pData, size_t dataSize) +{ + if (dataSize > 0 && pData) + { + SafeByteArray byteArray(dataSize); + memcpy(&byteArray[0], pData, dataSize); + + onDataForNetwork(byteArray); + } +} + +//------------------------------------------------------------------------ + +void SchannelContext::forwardDataToApplication(const void* pData, size_t dataSize) +{ + SafeByteArray byteArray(dataSize); + memcpy(&byteArray[0], pData, dataSize); + + onDataForApplication(byteArray); +} + +//------------------------------------------------------------------------ + +void SchannelContext::handleDataFromApplication(const SafeByteArray& data) +{ + // Don't attempt to send data until we're fully connected + if (m_state == Connecting) + return; + + // Encrypt the data + encryptAndSendData(data); +} + +//------------------------------------------------------------------------ + +void SchannelContext::handleDataFromNetwork(const SafeByteArray& data) +{ + switch (m_state) + { + case Connecting: + { + // We're still establishing the connection, so continue the handshake + continueHandshake(data); + } + break; + + case Connected: + { + // Decrypt the data + decryptAndProcessData(data); + } + break; + + default: + return; + } +} + +//------------------------------------------------------------------------ + +void SchannelContext::indicateError() +{ + m_state = Error; + m_receivedData.clear(); + onError(); +} + +//------------------------------------------------------------------------ + +void SchannelContext::decryptAndProcessData(const SafeByteArray& data) +{ + SecBuffer inBuffers[4] = {0}; + + appendNewData(data); + + while (!m_receivedData.empty()) + { + // + // MSDN: + // When using the Schannel SSP with contexts that are not connection oriented, on input, + // the structure must contain four SecBuffer structures. Exactly one buffer must be of type + // SECBUFFER_DATA and contain an encrypted message, which is decrypted in place. The remaining + // buffers are used for output and must be of type SECBUFFER_EMPTY. For connection-oriented + // contexts, a SECBUFFER_DATA type buffer must be supplied, as noted for nonconnection-oriented + // contexts. Additionally, a second SECBUFFER_TOKEN type buffer that contains a security token + // must also be supplied. + // + inBuffers[0].pvBuffer = (char*)(&m_receivedData[0]); + inBuffers[0].cbBuffer = (unsigned long)m_receivedData.size(); + inBuffers[0].BufferType = SECBUFFER_DATA; + + inBuffers[1].BufferType = SECBUFFER_EMPTY; + inBuffers[2].BufferType = SECBUFFER_EMPTY; + inBuffers[3].BufferType = SECBUFFER_EMPTY; + + SecBufferDesc inBufferDesc = {0}; + inBufferDesc.cBuffers = 4; + inBufferDesc.pBuffers = inBuffers; + inBufferDesc.ulVersion = SECBUFFER_VERSION; + + size_t inData = m_receivedData.size(); + SECURITY_STATUS status = DecryptMessage(m_ctxtHandle, &inBufferDesc, 0, NULL); + + if (status == SEC_E_INCOMPLETE_MESSAGE) + { + // Wait for more data to arrive + break; + } + else if (status == SEC_I_RENEGOTIATE) + { + // TODO: Handle renegotiation scenarios + indicateError(); + break; + } + else if (status == SEC_I_CONTEXT_EXPIRED) + { + indicateError(); + break; + } + else if (status != SEC_E_OK) + { + indicateError(); + break; + } + + SecBuffer* pDataBuffer = NULL; + SecBuffer* pExtraBuffer = NULL; + for (int i = 0; i < 4; ++i) + { + if (inBuffers[i].BufferType == SECBUFFER_DATA) + pDataBuffer = &inBuffers[i]; + + else if (inBuffers[i].BufferType == SECBUFFER_EXTRA) + pExtraBuffer = &inBuffers[i]; + } + + if (pDataBuffer && pDataBuffer->cbBuffer > 0 && pDataBuffer->pvBuffer != NULL) + forwardDataToApplication(pDataBuffer->pvBuffer, pDataBuffer->cbBuffer); + + // If there is extra data left over from the decryption operation, we call DecryptMessage() again + if (pExtraBuffer) + { + m_receivedData.erase(m_receivedData.begin(), m_receivedData.end() - pExtraBuffer->cbBuffer); + } + else + { + // We're done + m_receivedData.erase(m_receivedData.begin(), m_receivedData.begin() + inData); + } + } +} + +//------------------------------------------------------------------------ + +void SchannelContext::encryptAndSendData(const SafeByteArray& data) +{ + SecBuffer outBuffers[4] = {0}; + + // Calculate the largest required size of the send buffer + size_t messageBufferSize = (data.size() > m_streamSizes.cbMaximumMessage) + ? m_streamSizes.cbMaximumMessage + : data.size(); + + // Allocate a packet for the encrypted data + SafeByteArray sendBuffer; + sendBuffer.resize(m_streamSizes.cbHeader + messageBufferSize + m_streamSizes.cbTrailer); + + size_t bytesSent = 0; + do + { + size_t bytesLeftToSend = data.size() - bytesSent; + + // Calculate how much of the send buffer we'll be using for this chunk + size_t bytesToSend = (bytesLeftToSend > m_streamSizes.cbMaximumMessage) + ? m_streamSizes.cbMaximumMessage + : bytesLeftToSend; + + // Copy the plain text data into the send buffer + memcpy(&sendBuffer[0] + m_streamSizes.cbHeader, &data[0] + bytesSent, bytesToSend); + + outBuffers[0].pvBuffer = &sendBuffer[0]; + outBuffers[0].cbBuffer = m_streamSizes.cbHeader; + outBuffers[0].BufferType = SECBUFFER_STREAM_HEADER; + + outBuffers[1].pvBuffer = &sendBuffer[0] + m_streamSizes.cbHeader; + outBuffers[1].cbBuffer = (unsigned long)bytesToSend; + outBuffers[1].BufferType = SECBUFFER_DATA; + + outBuffers[2].pvBuffer = &sendBuffer[0] + m_streamSizes.cbHeader + bytesToSend; + outBuffers[2].cbBuffer = m_streamSizes.cbTrailer; + outBuffers[2].BufferType = SECBUFFER_STREAM_TRAILER; + + outBuffers[3].pvBuffer = 0; + outBuffers[3].cbBuffer = 0; + outBuffers[3].BufferType = SECBUFFER_EMPTY; + + SecBufferDesc outBufferDesc = {0}; + outBufferDesc.cBuffers = 4; + outBufferDesc.pBuffers = outBuffers; + outBufferDesc.ulVersion = SECBUFFER_VERSION; + + SECURITY_STATUS status = EncryptMessage(m_ctxtHandle, 0, &outBufferDesc, 0); + if (status != SEC_E_OK) + { + indicateError(); + return; + } + + sendDataOnNetwork(&sendBuffer[0], outBuffers[0].cbBuffer + outBuffers[1].cbBuffer + outBuffers[2].cbBuffer); + bytesSent += bytesToSend; + + } while (bytesSent < data.size()); +} + +//------------------------------------------------------------------------ + +bool SchannelContext::setClientCertificate(const PKCS12Certificate& certificate) +{ + return false; +} + +//------------------------------------------------------------------------ + +Certificate::ref SchannelContext::getPeerCertificate() const +{ + SchannelCertificate::ref pCertificate; + + ScopedCertContext pServerCert; + SECURITY_STATUS status = QueryContextAttributes(m_ctxtHandle, SECPKG_ATTR_REMOTE_CERT_CONTEXT, pServerCert.Reset()); + if (status != SEC_E_OK) + return pCertificate; + + pCertificate.reset( new SchannelCertificate(pServerCert) ); + return pCertificate; +} + +//------------------------------------------------------------------------ + +CertificateVerificationError::ref SchannelContext::getPeerCertificateVerificationError() const +{ + boost::shared_ptr<CertificateVerificationError> pCertError; + + if (m_state == Error) + pCertError.reset( new CertificateVerificationError(m_verificationError) ); + + return pCertError; +} + +//------------------------------------------------------------------------ + +ByteArray SchannelContext::getFinishMessage() const +{ + // TODO: Implement + + ByteArray emptyArray; + return emptyArray; +} + +//------------------------------------------------------------------------ + +} |