1 files changed, 294 insertions, 2 deletions

diff --git a/src/OSSupport/TCPLinkImpl.cpp b/src/OSSupport/TCPLinkImpl.cpp
index b15b6282f..d55dc9da1 100644
--- a/src/OSSupport/TCPLinkImpl.cpp
+++ b/src/OSSupport/TCPLinkImpl.cpp
@@ -48,6 +48,9 @@ cTCPLinkImpl::cTCPLinkImpl(evutil_socket_t a_Socket, cTCPLink::cCallbacksPtr a_L
 
 cTCPLinkImpl::~cTCPLinkImpl()
 {
+	// If the TLS context still exists, free it:
+	m_TlsContext.reset();
+
 	bufferevent_free(m_BufferEvent);
 }
 
@@ -129,7 +132,16 @@ bool cTCPLinkImpl::Send(const void * a_Data, size_t a_Length)
 		LOGD("%s: Cannot send data, the link is already shut down.", __FUNCTION__);
 		return false;
 	}
-	return (bufferevent_write(m_BufferEvent, a_Data, a_Length) == 0);
+
+	// If running in TLS mode, push the data into the TLS context instead:
+	if (m_TlsContext != nullptr)
+	{
+		m_TlsContext->Send(a_Data, a_Length);
+		return true;
+	}
+
+	// Send the data:
+	return SendRaw(a_Data, a_Length);
 }
 
 
@@ -138,6 +150,14 @@ bool cTCPLinkImpl::Send(const void * a_Data, size_t a_Length)
 
 void cTCPLinkImpl::Shutdown(void)
 {
+	// If running in TLS mode, notify the TLS layer:
+	if (m_TlsContext != nullptr)
+	{
+		m_TlsContext->NotifyClose();
+		m_TlsContext->ResetSelf();
+		m_TlsContext.reset();
+	}
+
 	// If there's no outgoing data, shutdown the socket directly:
 	if (evbuffer_get_length(bufferevent_get_output(m_BufferEvent)) == 0)
 	{
@@ -155,6 +175,14 @@ void cTCPLinkImpl::Shutdown(void)
 
 void cTCPLinkImpl::Close(void)
 {
+	// If running in TLS mode, notify the TLS layer:
+	if (m_TlsContext != nullptr)
+	{
+		m_TlsContext->NotifyClose();
+		m_TlsContext->ResetSelf();
+		m_TlsContext.reset();
+	}
+
 	// Disable all events on the socket, but keep it alive:
 	bufferevent_disable(m_BufferEvent, EV_READ | EV_WRITE);
 	if (m_Server == nullptr)
@@ -173,18 +201,98 @@ void cTCPLinkImpl::Close(void)
 
 
 
+AString cTCPLinkImpl::StartTLSClient(
+	cX509CertPtr a_OwnCert,
+	cCryptoKeyPtr a_OwnPrivKey
+)
+{
+	// Check preconditions:
+	if (m_TlsContext != nullptr)
+	{
+		return "TLS is already active on this link";
+	}
+	if (
+		((a_OwnCert == nullptr) && (a_OwnPrivKey != nullptr)) ||
+		((a_OwnCert != nullptr) && (a_OwnPrivKey != nullptr))
+	)
+	{
+		return "Either provide both the certificate and private key, or neither";
+	}
+
+	// Create the TLS context:
+	m_TlsContext.reset(new cLinkTlsContext(*this));
+	m_TlsContext->Initialize(true);
+	if (a_OwnCert != nullptr)
+	{
+		m_TlsContext->SetOwnCert(a_OwnCert, a_OwnPrivKey);
+	}
+	m_TlsContext->SetSelf(cLinkTlsContextWPtr(m_TlsContext));
+
+	// Start the handshake:
+	m_TlsContext->Handshake();
+	return "";
+}
+
+
+
+
+
+AString cTCPLinkImpl::StartTLSServer(
+	cX509CertPtr a_OwnCert,
+	cCryptoKeyPtr a_OwnPrivKey,
+	const AString & a_StartTLSData
+)
+{
+	// Check preconditions:
+	if (m_TlsContext != nullptr)
+	{
+		return "TLS is already active on this link";
+	}
+	if ((a_OwnCert == nullptr)  || (a_OwnPrivKey == nullptr))
+	{
+		return "Provide the server certificate and private key";
+	}
+
+	// Create the TLS context:
+	m_TlsContext.reset(new cLinkTlsContext(*this));
+	m_TlsContext->Initialize(false);
+	m_TlsContext->SetOwnCert(a_OwnCert, a_OwnPrivKey);
+	m_TlsContext->SetSelf(cLinkTlsContextWPtr(m_TlsContext));
+
+	// Push the initial data:
+	m_TlsContext->StoreReceivedData(a_StartTLSData.data(), a_StartTLSData.size());
+
+	// Start the handshake:
+	m_TlsContext->Handshake();
+	return "";
+}
+
+
+
+
+
 void cTCPLinkImpl::ReadCallback(bufferevent * a_BufferEvent, void * a_Self)
 {
 	ASSERT(a_Self != nullptr);
 	cTCPLinkImpl * Self = static_cast<cTCPLinkImpl *>(a_Self);
+	ASSERT(Self->m_BufferEvent == a_BufferEvent);
 	ASSERT(Self->m_Callbacks != nullptr);
 
 	// Read all the incoming data, in 1024-byte chunks:
 	char data[1024];
 	size_t length;
+	auto tlsContext = Self->m_TlsContext;
 	while ((length = bufferevent_read(a_BufferEvent, data, sizeof(data))) > 0)
 	{
-		Self->m_Callbacks->OnReceivedData(data, length);
+		if (tlsContext != nullptr)
+		{
+			ASSERT(tlsContext->IsLink(Self));
+			tlsContext->StoreReceivedData(data, length);
+		}
+		else
+		{
+			Self->ReceivedCleartextData(data, length);
+		}
 	}
 }
 
@@ -214,6 +322,11 @@ void cTCPLinkImpl::EventCallback(bufferevent * a_BufferEvent, short a_What, void
 {
 	ASSERT(a_Self != nullptr);
 	cTCPLinkImplPtr Self = static_cast<cTCPLinkImpl *>(a_Self)->m_Self;
+	if (Self == nullptr)
+	{
+		// The link has already been freed
+		return;
+	}
 
 	// If an error is reported, call the error callback:
 	if (a_What & BEV_EVENT_ERROR)
@@ -262,6 +375,13 @@ void cTCPLinkImpl::EventCallback(bufferevent * a_BufferEvent, short a_What, void
 	// If the connection has been closed, call the link callback and remove the connection:
 	if (a_What & BEV_EVENT_EOF)
 	{
+		// If running in TLS mode and there's data left in the TLS contect, report it:
+		auto tlsContext = Self->m_TlsContext;
+		if (tlsContext != nullptr)
+		{
+			tlsContext->FlushBuffers();
+		}
+
 		Self->m_Callbacks->OnRemoteClosed();
 		if (Self->m_Server != nullptr)
 		{
@@ -357,6 +477,178 @@ void cTCPLinkImpl::DoActualShutdown(void)
 
 
 
+bool cTCPLinkImpl::SendRaw(const void * a_Data, size_t a_Length)
+{
+	return (bufferevent_write(m_BufferEvent, a_Data, a_Length) == 0);
+}
+
+
+
+
+
+void cTCPLinkImpl::ReceivedCleartextData(const char * a_Data, size_t a_Length)
+{
+	ASSERT(m_Callbacks != nullptr);
+	m_Callbacks->OnReceivedData(a_Data, a_Length);
+}
+
+
+
+
+
+////////////////////////////////////////////////////////////////////////////////
+// cTCPLinkImpl::cLinkTlsContext:
+
+cTCPLinkImpl::cLinkTlsContext::cLinkTlsContext(cTCPLinkImpl & a_Link):
+	m_Link(a_Link)
+{
+}
+
+
+
+
+
+void cTCPLinkImpl::cLinkTlsContext::SetSelf(cLinkTlsContextWPtr a_Self)
+{
+	m_Self = a_Self;
+}
+
+
+
+
+
+void cTCPLinkImpl::cLinkTlsContext::ResetSelf(void)
+{
+	m_Self.reset();
+}
+
+
+
+
+
+void cTCPLinkImpl::cLinkTlsContext::StoreReceivedData(const char * a_Data, size_t a_NumBytes)
+{
+	// Hold self alive for the duration of this function
+	cLinkTlsContextPtr Self(m_Self);
+
+	m_EncryptedData.append(a_Data, a_NumBytes);
+
+	// Try to finish a pending handshake:
+	TryFinishHandshaking();
+
+	// Flush any cleartext data that can be "received":
+	FlushBuffers();
+}
+
+
+
+
+
+void cTCPLinkImpl::cLinkTlsContext::FlushBuffers(void)
+{
+	// Hold self alive for the duration of this function
+	cLinkTlsContextPtr Self(m_Self);
+
+	// If the handshake didn't complete yet, bail out:
+	if (!HasHandshaken())
+	{
+		return;
+	}
+
+	char Buffer[1024];
+	int NumBytes;
+	while ((NumBytes = ReadPlain(Buffer, sizeof(Buffer))) > 0)
+	{
+		m_Link.ReceivedCleartextData(Buffer, static_cast<size_t>(NumBytes));
+		if (m_Self.expired())
+		{
+			// The callback closed the SSL context, bail out
+			return;
+		}
+	}
+}
+
+
+
+
+
+void cTCPLinkImpl::cLinkTlsContext::TryFinishHandshaking(void)
+{
+	// Hold self alive for the duration of this function
+	cLinkTlsContextPtr Self(m_Self);
+
+	// If the handshake hasn't finished yet, retry:
+	if (!HasHandshaken())
+	{
+		Handshake();
+		// If the handshake succeeded, write all the queued plaintext data:
+		if (HasHandshaken())
+		{
+			m_Link.GetCallbacks()->OnTlsHandshakeCompleted();
+			WritePlain(m_CleartextData.data(), m_CleartextData.size());
+			m_CleartextData.clear();
+		}
+	}
+}
+
+
+
+
+
+void cTCPLinkImpl::cLinkTlsContext::Send(const void * a_Data, size_t a_Length)
+{
+	// Hold self alive for the duration of this function
+	cLinkTlsContextPtr Self(m_Self);
+
+	// If the handshake hasn't completed yet, queue the data:
+	if (!HasHandshaken())
+	{
+		m_CleartextData.append(reinterpret_cast<const char *>(a_Data), a_Length);
+		TryFinishHandshaking();
+		return;
+	}
+
+	// The connection is all set up, write the cleartext data into the SSL context:
+	WritePlain(a_Data, a_Length);
+	FlushBuffers();
+}
+
+
+
+
+
+int cTCPLinkImpl::cLinkTlsContext::ReceiveEncrypted(unsigned char * a_Buffer, size_t a_NumBytes)
+{
+	// Hold self alive for the duration of this function
+	cLinkTlsContextPtr Self(m_Self);
+
+	// If there's nothing queued in the buffer, report empty buffer:
+	if (m_EncryptedData.empty())
+	{
+		return POLARSSL_ERR_NET_WANT_READ;
+	}
+
+	// Copy as much data as possible to the provided buffer:
+	size_t BytesToCopy = std::min(a_NumBytes, m_EncryptedData.size());
+	memcpy(a_Buffer, m_EncryptedData.data(), BytesToCopy);
+	m_EncryptedData.erase(0, BytesToCopy);
+	return static_cast<int>(BytesToCopy);
+}
+
+
+
+
+
+int cTCPLinkImpl::cLinkTlsContext::SendEncrypted(const unsigned char * a_Buffer, size_t a_NumBytes)
+{
+	m_Link.SendRaw(a_Buffer, a_NumBytes);
+	return static_cast<int>(a_NumBytes);
+}
+
+
+
+
+
 ////////////////////////////////////////////////////////////////////////////////
 // cNetwork API: