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;
+}
+
+//------------------------------------------------------------------------
+
+}