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-rw-r--r--src/OSSupport/Network.h33
-rw-r--r--src/OSSupport/TCPLinkImpl.cpp296
-rw-r--r--src/OSSupport/TCPLinkImpl.h75
3 files changed, 402 insertions, 2 deletions
diff --git a/src/OSSupport/Network.h b/src/OSSupport/Network.h
index 1162d7fc6..78c5e92f0 100644
--- a/src/OSSupport/Network.h
+++ b/src/OSSupport/Network.h
@@ -20,6 +20,11 @@ typedef std::vector<cTCPLinkPtr> cTCPLinkPtrs;
class cServerHandle;
typedef SharedPtr<cServerHandle> cServerHandlePtr;
typedef std::vector<cServerHandlePtr> cServerHandlePtrs;
+class cCryptoKey;
+typedef SharedPtr<cCryptoKey> cCryptoKeyPtr;
+class cX509Cert;
+typedef SharedPtr<cX509Cert> cX509CertPtr;
+
@@ -49,6 +54,10 @@ public:
Sending data on the link is not an error, but the data won't be delivered. */
virtual void OnRemoteClosed(void) = 0;
+ /** Called when the TLS handshake has been completed and communication can continue regularly.
+ Has an empty default implementation, so that link callback descendants don't need to specify TLS handlers when they don't use TLS at all. */
+ virtual void OnTlsHandshakeCompleted(void) {}
+
/** Called when an error is detected on the connection. */
virtual void OnError(int a_ErrorCode, const AString & a_ErrorMsg) = 0;
};
@@ -90,6 +99,30 @@ public:
Sends the RST packet, queued outgoing and incoming data is lost. */
virtual void Close(void) = 0;
+ /** Starts a TLS handshake as a client connection.
+ If a client certificate should be used for the connection, set the certificate into a_OwnCertData and
+ its corresponding private key to a_OwnPrivKeyData. If both are empty, no client cert is presented.
+ a_OwnPrivKeyPassword is the password to be used for decoding PrivKey, empty if not passworded.
+ Returns empty string on success, non-empty error description on failure. */
+ virtual AString StartTLSClient(
+ cX509CertPtr a_OwnCert,
+ cCryptoKeyPtr a_OwnPrivKey
+ ) = 0;
+
+ /** Starts a TLS handshake as a server connection.
+ Set the server certificate into a_CertData and its corresponding private key to a_OwnPrivKeyData.
+ a_OwnPrivKeyPassword is the password to be used for decoding PrivKey, empty if not passworded.
+ a_StartTLSData is any data that should be pushed into the TLS before reading more data from the remote.
+ This is used mainly for protocols starting TLS in the middle of communication, when the TLS start command
+ can be received together with the TLS Client Hello message in one OnReceivedData() call, to re-queue the
+ Client Hello message into the TLS handshake buffer.
+ Returns empty string on success, non-empty error description on failure. */
+ virtual AString StartTLSServer(
+ cX509CertPtr a_OwnCert,
+ cCryptoKeyPtr a_OwnPrivKey,
+ const AString & a_StartTLSData
+ ) = 0;
+
/** Returns the callbacks that are used. */
cCallbacksPtr GetCallbacks(void) const { return m_Callbacks; }
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:
diff --git a/src/OSSupport/TCPLinkImpl.h b/src/OSSupport/TCPLinkImpl.h
index bea21aeff..b54c1a2cc 100644
--- a/src/OSSupport/TCPLinkImpl.h
+++ b/src/OSSupport/TCPLinkImpl.h
@@ -14,6 +14,7 @@
#include "Network.h"
#include <event2/event.h>
#include <event2/bufferevent.h>
+#include "../PolarSSL++/SslContext.h"
@@ -64,9 +65,73 @@ public:
virtual UInt16 GetRemotePort(void) const override { return m_RemotePort; }
virtual void Shutdown(void) override;
virtual void Close(void) override;
+ virtual AString StartTLSClient(
+ cX509CertPtr a_OwnCert,
+ cCryptoKeyPtr a_OwnPrivKey
+ ) override;
+ virtual AString StartTLSServer(
+ cX509CertPtr a_OwnCert,
+ cCryptoKeyPtr a_OwnPrivKey,
+ const AString & a_StartTLSData
+ ) override;
protected:
+ // fwd:
+ class cLinkTlsContext;
+ typedef SharedPtr<cLinkTlsContext> cLinkTlsContextPtr;
+ typedef WeakPtr<cLinkTlsContext> cLinkTlsContextWPtr;
+
+ /** Wrapper around cSslContext that is used when this link is being encrypted by SSL. */
+ class cLinkTlsContext :
+ public cSslContext
+ {
+ cTCPLinkImpl & m_Link;
+
+ /** Buffer for storing the incoming encrypted data until it is requested by the SSL decryptor. */
+ AString m_EncryptedData;
+
+ /** Buffer for storing the outgoing cleartext data until the link has finished handshaking. */
+ AString m_CleartextData;
+
+ /** Shared ownership of self, so that this object can keep itself alive for as long as it needs. */
+ cLinkTlsContextWPtr m_Self;
+
+ public:
+ cLinkTlsContext(cTCPLinkImpl & a_Link);
+
+ /** Shares ownership of self, so that this object can keep itself alive for as long as it needs. */
+ void SetSelf(cLinkTlsContextWPtr a_Self);
+
+ /** Removes the self ownership so that we can detect the SSL closure. */
+ void ResetSelf(void);
+
+ /** Stores the specified block of data into the buffer of the data to be decrypted (incoming from remote).
+ Also flushes the SSL buffers by attempting to read any data through the SSL context. */
+ void StoreReceivedData(const char * a_Data, size_t a_NumBytes);
+
+ /** Tries to read any cleartext data available through the SSL, reports it in the link. */
+ void FlushBuffers(void);
+
+ /** Tries to finish handshaking the SSL. */
+ void TryFinishHandshaking(void);
+
+ /** Sends the specified cleartext data over the SSL to the remote peer.
+ If the handshake hasn't been completed yet, queues the data for sending when it completes. */
+ void Send(const void * a_Data, size_t a_Length);
+
+ // cSslContext overrides:
+ virtual int ReceiveEncrypted(unsigned char * a_Buffer, size_t a_NumBytes) override;
+ virtual int SendEncrypted(const unsigned char * a_Buffer, size_t a_NumBytes) override;
+
+ /** Returns true if the context's associated TCP link is the same link as a_Link. */
+ bool IsLink(cTCPLinkImpl * a_Link)
+ {
+ return (a_Link == &m_Link);
+ }
+ };
+
+
/** Callbacks to call when the connection is established.
May be NULL if not used. Only used for outgoing connections (cNetwork::Connect()). */
cNetwork::cConnectCallbacksPtr m_ConnectCallbacks;
@@ -99,6 +164,10 @@ protected:
data is sent to the OS TCP stack, the socket gets shut down. */
bool m_ShouldShutdown;
+ /** The SSL context used for encryption, if this link uses SSL.
+ If valid, the link uses encryption through this context. */
+ cLinkTlsContextPtr m_TlsContext;
+
/** Creates a new link to be queued to connect to a specified host:port.
Used for outgoing connections created using cNetwork::Connect().
@@ -127,6 +196,12 @@ protected:
/** Calls shutdown on the link and disables LibEvent writing.
Called after all data from LibEvent buffers is sent to the OS TCP stack and shutdown() has been called before. */
void DoActualShutdown(void);
+
+ /** Sends the data directly to the socket (without the optional TLS). */
+ bool SendRaw(const void * a_Data, size_t a_Length);
+
+ /** Called by the TLS when it has decoded a piece of incoming cleartext data from the socket. */
+ void ReceivedCleartextData(const char * a_Data, size_t a_Length);
};
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