1 files changed, 131 insertions, 12 deletions
diff --git a/Swiften/TLS/Schannel/SchannelContext.cpp b/Swiften/TLS/Schannel/SchannelContext.cpp
index b2fea65..9be1ded 100644
--- a/Swiften/TLS/Schannel/SchannelContext.cpp
+++ b/Swiften/TLS/Schannel/SchannelContext.cpp
@@ -1,219 +1,289 @@
 /*
  * 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>
+#include "Swiften/TLS/Schannel/SchannelContext.h"
+#include "Swiften/TLS/Schannel/SchannelCertificate.h"
 #include <Swiften/TLS/CAPICertificate.h>
+#include <WinHTTP.h> // For SECURITY_FLAG_IGNORE_CERT_CN_INVALID
 
 namespace Swift {
 
 //------------------------------------------------------------------------
 
 SchannelContext::SchannelContext() 
 : m_state(Start)
 , m_secContext(0)
-, m_verificationError(CertificateVerificationError::UnknownError)
 , m_my_cert_store(NULL)
 , m_cert_store_name("MY")
 , m_cert_name()
 {
 	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));
 }
 
 //------------------------------------------------------------------------
 
 SchannelContext::~SchannelContext()
 {
 	if (m_my_cert_store) CertCloseStore(m_my_cert_store, 0);
 }
 
 //------------------------------------------------------------------------
 
 void SchannelContext::determineStreamSizes()
 {
 	QueryContextAttributes(m_ctxtHandle, SECPKG_ATTR_STREAM_SIZES, &m_streamSizes);
 }
 
 //------------------------------------------------------------------------
 
 void SchannelContext::connect() 
 {
-	PCCERT_CONTEXT   pCertContext = NULL;
+	ScopedCertContext pCertContext;
 
 	m_state = Connecting;
 
 	// If a user name is specified, then attempt to find a client
 	// certificate. Otherwise, just create a NULL credential.
 	if (!m_cert_name.empty())
 	{
 		if (m_my_cert_store == NULL)
 		{
 			m_my_cert_store = CertOpenSystemStore(0, m_cert_store_name.c_str());
 			if (!m_my_cert_store)
 			{
 /////			printf( "**** Error 0x%x returned by CertOpenSystemStore\n", GetLastError() );
 				indicateError();
 				return;
 			}
 		}
 
 		pCertContext = findCertificateInStore( m_my_cert_store, m_cert_name );
 		if (pCertContext == NULL)
 		{
 /////		printf("**** Error 0x%x returned by CertFindCertificateInStore\n", GetLastError());
 			indicateError();
 			return;
 		}
 	}
 
 	// We use an empty list for client certificates
 	PCCERT_CONTEXT clientCerts[1] = {0};
 
 	SCHANNEL_CRED sc = {0};
 	sc.dwVersion = SCHANNEL_CRED_VERSION;
 
 /////SSL3?
 	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_REVOCATION_CHECK_CHAIN;
+	sc.dwFlags = SCH_CRED_MANUAL_CRED_VALIDATION;
 
 	if (pCertContext)
 	{
 		sc.cCreds = 1;
-		sc.paCred = &pCertContext;
+		sc.paCred = pCertContext.GetPointer();
 		sc.dwFlags |= SCH_CRED_NO_DEFAULT_CREDS;
 	}
 	else
 	{
 		sc.cCreds = 0; // Let Crypto API find the appropriate certificate for us
 		sc.paCred = clientCerts;
 		sc.dwFlags |= SCH_CRED_USE_DEFAULT_CREDS;
 	}
 
 	// 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);
-
-	// cleanup: Free the certificate context. Schannel has already made its own copy.
-	if (pCertContext) CertFreeCertificateContext(pCertContext);
-
+	
 	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
+		handleCertError(status);
 		indicateError();
 		return;
 	}
 
 	// Start the handshake
 	sendDataOnNetwork(outBuffers[0].pvBuffer, outBuffers[0].cbBuffer);
 
 	if (status == SEC_E_OK) 
 	{
+		status = validateServerCertificate();
+		if (status != SEC_E_OK)
+			handleCertError(status);
+
 		m_state = Connected;
 		determineStreamSizes();
 
 		onConnected();
 	}
 }
 
 //------------------------------------------------------------------------
 
+SECURITY_STATUS SchannelContext::validateServerCertificate()
+{
+	SchannelCertificate::ref pServerCert = boost::dynamic_pointer_cast<SchannelCertificate>( getPeerCertificate() );
+	if (!pServerCert)
+		return SEC_E_WRONG_PRINCIPAL;
+
+	const LPSTR usage[] = 
+	{
+		szOID_PKIX_KP_SERVER_AUTH,
+		szOID_SERVER_GATED_CRYPTO,
+		szOID_SGC_NETSCAPE
+	};
+
+	CERT_CHAIN_PARA chainParams = {0};
+	chainParams.cbSize = sizeof(chainParams);
+	chainParams.RequestedUsage.dwType = USAGE_MATCH_TYPE_OR;
+	chainParams.RequestedUsage.Usage.cUsageIdentifier = ARRAYSIZE(usage);
+	chainParams.RequestedUsage.Usage.rgpszUsageIdentifier = const_cast<LPSTR*>(usage);
+
+	DWORD chainFlags = CERT_CHAIN_CACHE_END_CERT | CERT_CHAIN_REVOCATION_CHECK_CHAIN_EXCLUDE_ROOT;
+
+	ScopedCertChainContext pChainContext;
+
+	BOOL success = CertGetCertificateChain(
+		NULL, // Use the chain engine for the current user (assumes a user is logged in)
+		pServerCert->getCertContext(),
+		NULL,
+		NULL,
+		&chainParams,
+		chainFlags,
+		NULL,
+		pChainContext.Reset());
+
+	if (!success)
+		return GetLastError();
+
+	SSL_EXTRA_CERT_CHAIN_POLICY_PARA sslChainPolicy = {0};
+	sslChainPolicy.cbSize = sizeof(sslChainPolicy);
+	sslChainPolicy.dwAuthType = AUTHTYPE_SERVER;
+	sslChainPolicy.fdwChecks = SECURITY_FLAG_IGNORE_CERT_CN_INVALID; // Swiften checks the server name for us. Is this the correct way to disable server name checking?
+	sslChainPolicy.pwszServerName = NULL;
+
+	CERT_CHAIN_POLICY_PARA certChainPolicy = {0};
+	certChainPolicy.cbSize = sizeof(certChainPolicy);
+	certChainPolicy.dwFlags = CERT_CHAIN_POLICY_IGNORE_INVALID_NAME_FLAG; // Swiften checks the server name for us. Is this the correct way to disable server name checking?
+	certChainPolicy.pvExtraPolicyPara = &sslChainPolicy;
+
+	CERT_CHAIN_POLICY_STATUS certChainPolicyStatus = {0};
+	certChainPolicyStatus.cbSize = sizeof(certChainPolicyStatus);
+
+	// Verify the chain
+	if (!CertVerifyCertificateChainPolicy(
+		CERT_CHAIN_POLICY_SSL,
+		pChainContext,
+		&certChainPolicy,
+		&certChainPolicyStatus))
+	{
+		return GetLastError();
+	}
+
+	if (certChainPolicyStatus.dwError != S_OK)
+		return certChainPolicyStatus.dwError;
+
+	return S_OK;
+}
+
+//------------------------------------------------------------------------
+
 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;
@@ -238,93 +308,139 @@ void SchannelContext::continueHandshake(const SafeByteArray& data)
 			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) 
 		{
+			status = validateServerCertificate();
+			if (status != SEC_E_OK)
+				handleCertError(status);
+
 			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
+			handleCertError(status);
 			indicateError();
 			return;
 		}
 	}
 }
 
 //------------------------------------------------------------------------
 
+void SchannelContext::handleCertError(SECURITY_STATUS status) 
+{
+	if (status == SEC_E_UNTRUSTED_ROOT			|| 
+		status == CERT_E_UNTRUSTEDROOT			||
+		status == CRYPT_E_ISSUER_SERIALNUMBER	|| 
+		status == CRYPT_E_SIGNER_NOT_FOUND		||
+		status == CRYPT_E_NO_TRUSTED_SIGNER)
+	{
+		m_verificationError = CertificateVerificationError::Untrusted;
+	}
+	else if (status == SEC_E_CERT_EXPIRED || 
+			 status == CERT_E_EXPIRED)
+	{
+		m_verificationError = CertificateVerificationError::Expired;
+	}
+	else if (status == CRYPT_E_SELF_SIGNED)
+	{
+		m_verificationError = CertificateVerificationError::SelfSigned;
+	}
+	else if (status == CRYPT_E_HASH_VALUE	||
+			 status == TRUST_E_CERT_SIGNATURE)
+	{
+		m_verificationError = CertificateVerificationError::InvalidSignature;
+	}
+	else if (status == CRYPT_E_REVOKED)
+	{
+		m_verificationError = CertificateVerificationError::Revoked;
+	}
+	else if (status == CRYPT_E_NO_REVOCATION_CHECK ||
+			 status == CRYPT_E_REVOCATION_OFFLINE)
+	{
+		m_verificationError = CertificateVerificationError::RevocationCheckFailed;
+	}
+	else
+	{
+		m_verificationError = CertificateVerificationError::UnknownError;
+	}
+}
+
+//------------------------------------------------------------------------
+
 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);
 }
 
 //------------------------------------------------------------------------
 
@@ -417,70 +533,73 @@ void SchannelContext::decryptAndProcessData(const SafeByteArray& data)
 			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) 
 {	
+	if (m_streamSizes.cbMaximumMessage == 0)
+		return;
+
 	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;
@@ -512,54 +631,54 @@ void SchannelContext::encryptAndSendData(const SafeByteArray& data)
 bool SchannelContext::setClientCertificate(CertificateWithKey::ref certificate)
 {
 	boost::shared_ptr<CAPICertificate> capiCertificate = boost::dynamic_pointer_cast<CAPICertificate>(certificate);
 	if (!capiCertificate || capiCertificate->isNull()) {
 		return false;
 	}
 
 	// We assume that the Certificate Store Name/Certificate Name
 	// are valid at this point
 	m_cert_store_name = capiCertificate->getCertStoreName();
 	m_cert_name = capiCertificate->getCertName();
 	return true;
 }
 
 //------------------------------------------------------------------------
 
 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) );
+	if (m_verificationError)
+		pCertError.reset( new CertificateVerificationError(*m_verificationError) );
 	
 	return pCertError;
 }
 
 //------------------------------------------------------------------------
 
 ByteArray SchannelContext::getFinishMessage() const
 {
 	// TODO: Implement
 
 	ByteArray emptyArray;
 	return emptyArray;
 }
 
 //------------------------------------------------------------------------
 
 }