1 files changed, 123 insertions, 61 deletions
diff --git a/Swiften/Client/ClientSession.cpp b/Swiften/Client/ClientSession.cpp
index c301881..bcfb004 100644
--- a/Swiften/Client/ClientSession.cpp
+++ b/Swiften/Client/ClientSession.cpp
@@ -1,514 +1,576 @@
 /*
  * Copyright (c) 2010-2016 Isode Limited.
  * All rights reserved.
  * See the COPYING file for more information.
  */
 
 #include <Swiften/Client/ClientSession.h>
 
+#include <memory>
+
 #include <boost/bind.hpp>
 #include <boost/uuid/uuid.hpp>
 #include <boost/uuid/uuid_io.hpp>
 #include <boost/uuid/uuid_generators.hpp>
-#include <memory>
 
-#include <Swiften/Base/Platform.h>
 #include <Swiften/Base/Log.h>
-#include <Swiften/Elements/ProtocolHeader.h>
-#include <Swiften/Elements/StreamFeatures.h>
-#include <Swiften/Elements/StreamError.h>
-#include <Swiften/Elements/StartTLSRequest.h>
-#include <Swiften/Elements/StartTLSFailure.h>
-#include <Swiften/Elements/TLSProceed.h>
-#include <Swiften/Elements/AuthRequest.h>
-#include <Swiften/Elements/AuthSuccess.h>
-#include <Swiften/Elements/AuthFailure.h>
+#include <Swiften/Base/Platform.h>
+#include <Swiften/Crypto/CryptoProvider.h>
 #include <Swiften/Elements/AuthChallenge.h>
+#include <Swiften/Elements/AuthFailure.h>
+#include <Swiften/Elements/AuthRequest.h>
 #include <Swiften/Elements/AuthResponse.h>
-#include <Swiften/Elements/Compressed.h>
+#include <Swiften/Elements/AuthSuccess.h>
 #include <Swiften/Elements/CompressFailure.h>
 #include <Swiften/Elements/CompressRequest.h>
+#include <Swiften/Elements/Compressed.h>
 #include <Swiften/Elements/EnableStreamManagement.h>
-#include <Swiften/Elements/StreamManagementEnabled.h>
-#include <Swiften/Elements/StreamManagementFailed.h>
-#include <Swiften/Elements/StartSession.h>
-#include <Swiften/Elements/StanzaAck.h>
-#include <Swiften/Elements/StanzaAckRequest.h>
 #include <Swiften/Elements/IQ.h>
+#include <Swiften/Elements/ProtocolHeader.h>
 #include <Swiften/Elements/ResourceBind.h>
-#include <Swiften/SASL/PLAINClientAuthenticator.h>
+#include <Swiften/Elements/StanzaAck.h>
+#include <Swiften/Elements/StanzaAckRequest.h>
+#include <Swiften/Elements/StartSession.h>
+#include <Swiften/Elements/StartTLSFailure.h>
+#include <Swiften/Elements/StartTLSRequest.h>
+#include <Swiften/Elements/StreamError.h>
+#include <Swiften/Elements/StreamFeatures.h>
+#include <Swiften/Elements/StreamManagementEnabled.h>
+#include <Swiften/Elements/StreamManagementFailed.h>
+#include <Swiften/Elements/TLSProceed.h>
+#include <Swiften/Network/Timer.h>
+#include <Swiften/Network/TimerFactory.h>
+#include <Swiften/SASL/DIGESTMD5ClientAuthenticator.h>
 #include <Swiften/SASL/EXTERNALClientAuthenticator.h>
+#include <Swiften/SASL/PLAINClientAuthenticator.h>
 #include <Swiften/SASL/SCRAMSHA1ClientAuthenticator.h>
-#include <Swiften/SASL/DIGESTMD5ClientAuthenticator.h>
-#include <Swiften/Crypto/CryptoProvider.h>
 #include <Swiften/Session/SessionStream.h>
+#include <Swiften/StreamManagement/StanzaAckRequester.h>
+#include <Swiften/StreamManagement/StanzaAckResponder.h>
 #include <Swiften/TLS/CertificateTrustChecker.h>
 #include <Swiften/TLS/ServerIdentityVerifier.h>
 
 #ifdef SWIFTEN_PLATFORM_WIN32
 #include <Swiften/Base/WindowsRegistry.h>
 #include <Swiften/SASL/WindowsGSSAPIClientAuthenticator.h>
 #endif
 
 #define CHECK_STATE_OR_RETURN(a) \
     if (!checkState(a)) { return; }
 
 namespace Swift {
 
 ClientSession::ClientSession(
         const JID& jid,
         std::shared_ptr<SessionStream> stream,
         IDNConverter* idnConverter,
-        CryptoProvider* crypto) :
+        CryptoProvider* crypto,
+        TimerFactory* timerFactory) :
             localJID(jid),
-            state(Initial),
+            state(State::Initial),
             stream(stream),
             idnConverter(idnConverter),
             crypto(crypto),
+            timerFactory(timerFactory),
             allowPLAINOverNonTLS(false),
             useStreamCompression(true),
             useTLS(UseTLSWhenAvailable),
             useAcks(true),
             needSessionStart(false),
             needResourceBind(false),
             needAcking(false),
             rosterVersioningSupported(false),
             authenticator(nullptr),
             certificateTrustChecker(nullptr),
             singleSignOn(false),
             authenticationPort(-1) {
 #ifdef SWIFTEN_PLATFORM_WIN32
 if (WindowsRegistry::isFIPSEnabled()) {
     SWIFT_LOG(info) << "Windows is running in FIPS-140 mode. Some authentication methods will be unavailable." << std::endl;
 }
 #endif
 }
 
 ClientSession::~ClientSession() {
 }
 
 void ClientSession::start() {
     stream->onStreamStartReceived.connect(boost::bind(&ClientSession::handleStreamStart, shared_from_this(), _1));
+    stream->onStreamEndReceived.connect(boost::bind(&ClientSession::handleStreamEnd, shared_from_this()));
     stream->onElementReceived.connect(boost::bind(&ClientSession::handleElement, shared_from_this(), _1));
     stream->onClosed.connect(boost::bind(&ClientSession::handleStreamClosed, shared_from_this(), _1));
     stream->onTLSEncrypted.connect(boost::bind(&ClientSession::handleTLSEncrypted, shared_from_this()));
 
-    assert(state == Initial);
-    state = WaitingForStreamStart;
+    assert(state == State::Initial);
+    state = State::WaitingForStreamStart;
     sendStreamHeader();
 }
 
 void ClientSession::sendStreamHeader() {
     ProtocolHeader header;
     header.setTo(getRemoteJID());
     stream->writeHeader(header);
 }
 
 void ClientSession::sendStanza(std::shared_ptr<Stanza> stanza) {
     stream->writeElement(stanza);
     if (stanzaAckRequester_) {
         stanzaAckRequester_->handleStanzaSent(stanza);
     }
 }
 
 void ClientSession::handleStreamStart(const ProtocolHeader&) {
-    CHECK_STATE_OR_RETURN(WaitingForStreamStart);
-    state = Negotiating;
+    CHECK_STATE_OR_RETURN(State::WaitingForStreamStart);
+    state = State::Negotiating;
+}
+
+void ClientSession::handleStreamEnd() {
+    if (state == State::Finishing) {
+        // We are already in finishing state if we iniated the close of the session.
+        stream->close();
+    }
+    else {
+        state = State::Finishing;
+        initiateShutdown(true);
+    }
 }
 
 void ClientSession::handleElement(std::shared_ptr<ToplevelElement> element) {
     if (std::shared_ptr<Stanza> stanza = std::dynamic_pointer_cast<Stanza>(element)) {
         if (stanzaAckResponder_) {
             stanzaAckResponder_->handleStanzaReceived();
         }
-        if (getState() == Initialized) {
+        if (getState() == State::Initialized) {
             onStanzaReceived(stanza);
         }
         else if (std::shared_ptr<IQ> iq = std::dynamic_pointer_cast<IQ>(element)) {
-            if (state == BindingResource) {
+            if (state == State::BindingResource) {
                 std::shared_ptr<ResourceBind> resourceBind(iq->getPayload<ResourceBind>());
                 if (iq->getType() == IQ::Error && iq->getID() == "session-bind") {
                     finishSession(Error::ResourceBindError);
                 }
                 else if (!resourceBind) {
                     finishSession(Error::UnexpectedElementError);
                 }
                 else if (iq->getType() == IQ::Result) {
                     localJID = resourceBind->getJID();
                     if (!localJID.isValid()) {
                         finishSession(Error::ResourceBindError);
                     }
                     needResourceBind = false;
                     continueSessionInitialization();
                 }
                 else {
                     finishSession(Error::UnexpectedElementError);
                 }
             }
-            else if (state == StartingSession) {
+            else if (state == State::StartingSession) {
                 if (iq->getType() == IQ::Result) {
                     needSessionStart = false;
                     continueSessionInitialization();
                 }
                 else if (iq->getType() == IQ::Error) {
                     finishSession(Error::SessionStartError);
                 }
                 else {
                     finishSession(Error::UnexpectedElementError);
                 }
             }
             else {
                 finishSession(Error::UnexpectedElementError);
             }
         }
     }
     else if (std::dynamic_pointer_cast<StanzaAckRequest>(element)) {
         if (stanzaAckResponder_) {
             stanzaAckResponder_->handleAckRequestReceived();
         }
     }
     else if (std::shared_ptr<StanzaAck> ack = std::dynamic_pointer_cast<StanzaAck>(element)) {
         if (stanzaAckRequester_) {
             if (ack->isValid()) {
                 stanzaAckRequester_->handleAckReceived(ack->getHandledStanzasCount());
             }
             else {
                 SWIFT_LOG(warning) << "Got invalid ack from server";
             }
         }
         else {
             SWIFT_LOG(warning) << "Ignoring ack";
         }
     }
     else if (StreamError::ref streamError = std::dynamic_pointer_cast<StreamError>(element)) {
         finishSession(Error::StreamError);
     }
-    else if (getState() == Initialized) {
+    else if (getState() == State::Initialized) {
         std::shared_ptr<Stanza> stanza = std::dynamic_pointer_cast<Stanza>(element);
         if (stanza) {
             if (stanzaAckResponder_) {
                 stanzaAckResponder_->handleStanzaReceived();
             }
             onStanzaReceived(stanza);
         }
     }
     else if (StreamFeatures* streamFeatures = dynamic_cast<StreamFeatures*>(element.get())) {
-        CHECK_STATE_OR_RETURN(Negotiating);
+        CHECK_STATE_OR_RETURN(State::Negotiating);
 
         if (streamFeatures->hasStartTLS() && stream->supportsTLSEncryption() && useTLS != NeverUseTLS) {
-            state = WaitingForEncrypt;
+            state = State::WaitingForEncrypt;
             stream->writeElement(std::make_shared<StartTLSRequest>());
         }
         else if (useTLS == RequireTLS && !stream->isTLSEncrypted()) {
             finishSession(Error::NoSupportedAuthMechanismsError);
         }
         else if (useStreamCompression && stream->supportsZLibCompression() && streamFeatures->hasCompressionMethod("zlib")) {
-            state = Compressing;
+            state = State::Compressing;
             stream->writeElement(std::make_shared<CompressRequest>("zlib"));
         }
         else if (streamFeatures->hasAuthenticationMechanisms()) {
 #ifdef SWIFTEN_PLATFORM_WIN32
             if (singleSignOn) {
                 const boost::optional<std::string> authenticationHostname = streamFeatures->getAuthenticationHostname();
                 bool gssapiSupported = streamFeatures->hasAuthenticationMechanism("GSSAPI") && authenticationHostname && !authenticationHostname->empty();
 
                 if (!gssapiSupported) {
                     finishSession(Error::NoSupportedAuthMechanismsError);
                 }
                 else {
                     WindowsGSSAPIClientAuthenticator* gssapiAuthenticator = new WindowsGSSAPIClientAuthenticator(*authenticationHostname, localJID.getDomain(), authenticationPort);
                     std::shared_ptr<Error> error = std::make_shared<Error>(Error::AuthenticationFailedError);
 
                     authenticator = gssapiAuthenticator;
 
                     if (!gssapiAuthenticator->isError()) {
-                        state = Authenticating;
+                        state = State::Authenticating;
                         stream->writeElement(std::make_shared<AuthRequest>(authenticator->getName(), authenticator->getResponse()));
                     }
                     else {
                         error->errorCode = gssapiAuthenticator->getErrorCode();
                         finishSession(error);
                     }
                 }
             }
             else
 #endif
             if (stream->hasTLSCertificate()) {
                 if (streamFeatures->hasAuthenticationMechanism("EXTERNAL")) {
                     authenticator = new EXTERNALClientAuthenticator();
-                    state = Authenticating;
+                    state = State::Authenticating;
                     stream->writeElement(std::make_shared<AuthRequest>("EXTERNAL", createSafeByteArray("")));
                 }
                 else {
                     finishSession(Error::TLSClientCertificateError);
                 }
             }
             else if (streamFeatures->hasAuthenticationMechanism("EXTERNAL")) {
                 authenticator = new EXTERNALClientAuthenticator();
-                state = Authenticating;
+                state = State::Authenticating;
                 stream->writeElement(std::make_shared<AuthRequest>("EXTERNAL", createSafeByteArray("")));
             }
             else if (streamFeatures->hasAuthenticationMechanism("SCRAM-SHA-1") || streamFeatures->hasAuthenticationMechanism("SCRAM-SHA-1-PLUS")) {
                 std::ostringstream s;
                 ByteArray finishMessage;
                 bool plus = streamFeatures->hasAuthenticationMechanism("SCRAM-SHA-1-PLUS");
                 if (stream->isTLSEncrypted()) {
                     finishMessage = stream->getTLSFinishMessage();
                     plus &= !finishMessage.empty();
                 }
                 s << boost::uuids::random_generator()();
                 SCRAMSHA1ClientAuthenticator* scramAuthenticator = new SCRAMSHA1ClientAuthenticator(s.str(), plus, idnConverter, crypto);
                 if (!finishMessage.empty()) {
                     scramAuthenticator->setTLSChannelBindingData(finishMessage);
                 }
                 authenticator = scramAuthenticator;
-                state = WaitingForCredentials;
+                state = State::WaitingForCredentials;
                 onNeedCredentials();
             }
             else if ((stream->isTLSEncrypted() || allowPLAINOverNonTLS) && streamFeatures->hasAuthenticationMechanism("PLAIN")) {
                 authenticator = new PLAINClientAuthenticator();
-                state = WaitingForCredentials;
+                state = State::WaitingForCredentials;
                 onNeedCredentials();
             }
             else if (streamFeatures->hasAuthenticationMechanism("DIGEST-MD5") && crypto->isMD5AllowedForCrypto()) {
                 std::ostringstream s;
                 s << boost::uuids::random_generator()();
                 // FIXME: Host should probably be the actual host
                 authenticator = new DIGESTMD5ClientAuthenticator(localJID.getDomain(), s.str(), crypto);
-                state = WaitingForCredentials;
+                state = State::WaitingForCredentials;
                 onNeedCredentials();
             }
             else {
                 finishSession(Error::NoSupportedAuthMechanismsError);
             }
         }
         else {
             // Start the session
             rosterVersioningSupported = streamFeatures->hasRosterVersioning();
             stream->setWhitespacePingEnabled(true);
             needSessionStart = streamFeatures->hasSession();
             needResourceBind = streamFeatures->hasResourceBind();
             needAcking = streamFeatures->hasStreamManagement() && useAcks;
             if (!needResourceBind) {
                 // Resource binding is a MUST
                 finishSession(Error::ResourceBindError);
             }
             else {
                 continueSessionInitialization();
             }
         }
     }
     else if (std::dynamic_pointer_cast<Compressed>(element)) {
-        CHECK_STATE_OR_RETURN(Compressing);
-        state = WaitingForStreamStart;
+        CHECK_STATE_OR_RETURN(State::Compressing);
+        state = State::WaitingForStreamStart;
         stream->addZLibCompression();
         stream->resetXMPPParser();
         sendStreamHeader();
     }
     else if (std::dynamic_pointer_cast<CompressFailure>(element)) {
         finishSession(Error::CompressionFailedError);
     }
     else if (std::dynamic_pointer_cast<StreamManagementEnabled>(element)) {
         stanzaAckRequester_ = std::make_shared<StanzaAckRequester>();
         stanzaAckRequester_->onRequestAck.connect(boost::bind(&ClientSession::requestAck, shared_from_this()));
         stanzaAckRequester_->onStanzaAcked.connect(boost::bind(&ClientSession::handleStanzaAcked, shared_from_this(), _1));
         stanzaAckResponder_ = std::make_shared<StanzaAckResponder>();
         stanzaAckResponder_->onAck.connect(boost::bind(&ClientSession::ack, shared_from_this(), _1));
         needAcking = false;
         continueSessionInitialization();
     }
     else if (std::dynamic_pointer_cast<StreamManagementFailed>(element)) {
         needAcking = false;
         continueSessionInitialization();
     }
     else if (AuthChallenge* challenge = dynamic_cast<AuthChallenge*>(element.get())) {
-        CHECK_STATE_OR_RETURN(Authenticating);
+        CHECK_STATE_OR_RETURN(State::Authenticating);
         assert(authenticator);
         if (authenticator->setChallenge(challenge->getValue())) {
             stream->writeElement(std::make_shared<AuthResponse>(authenticator->getResponse()));
         }
 #ifdef SWIFTEN_PLATFORM_WIN32
         else if (WindowsGSSAPIClientAuthenticator* gssapiAuthenticator = dynamic_cast<WindowsGSSAPIClientAuthenticator*>(authenticator)) {
             std::shared_ptr<Error> error = std::make_shared<Error>(Error::AuthenticationFailedError);
 
             error->errorCode = gssapiAuthenticator->getErrorCode();
             finishSession(error);
         }
 #endif
         else {
             finishSession(Error::AuthenticationFailedError);
         }
     }
     else if (AuthSuccess* authSuccess = dynamic_cast<AuthSuccess*>(element.get())) {
-        CHECK_STATE_OR_RETURN(Authenticating);
+        CHECK_STATE_OR_RETURN(State::Authenticating);
         assert(authenticator);
         if (!authenticator->setChallenge(authSuccess->getValue())) {
             finishSession(Error::ServerVerificationFailedError);
         }
         else {
-            state = WaitingForStreamStart;
+            state = State::WaitingForStreamStart;
             delete authenticator;
             authenticator = nullptr;
             stream->resetXMPPParser();
             sendStreamHeader();
         }
     }
     else if (dynamic_cast<AuthFailure*>(element.get())) {
         finishSession(Error::AuthenticationFailedError);
     }
     else if (dynamic_cast<TLSProceed*>(element.get())) {
-        CHECK_STATE_OR_RETURN(WaitingForEncrypt);
-        state = Encrypting;
+        CHECK_STATE_OR_RETURN(State::WaitingForEncrypt);
+        state = State::Encrypting;
         stream->addTLSEncryption();
     }
     else if (dynamic_cast<StartTLSFailure*>(element.get())) {
         finishSession(Error::TLSError);
     }
     else {
         // FIXME Not correct?
-        state = Initialized;
+        state = State::Initialized;
         onInitialized();
     }
 }
 
 void ClientSession::continueSessionInitialization() {
     if (needResourceBind) {
-        state = BindingResource;
+        state = State::BindingResource;
         std::shared_ptr<ResourceBind> resourceBind(std::make_shared<ResourceBind>());
         if (!localJID.getResource().empty()) {
             resourceBind->setResource(localJID.getResource());
         }
         sendStanza(IQ::createRequest(IQ::Set, JID(), "session-bind", resourceBind));
     }
     else if (needAcking) {
-        state = EnablingSessionManagement;
+        state = State::EnablingSessionManagement;
         stream->writeElement(std::make_shared<EnableStreamManagement>());
     }
     else if (needSessionStart) {
-        state = StartingSession;
+        state = State::StartingSession;
         sendStanza(IQ::createRequest(IQ::Set, JID(), "session-start", std::make_shared<StartSession>()));
     }
     else {
-        state = Initialized;
+        state = State::Initialized;
         onInitialized();
     }
 }
 
 bool ClientSession::checkState(State state) {
     if (this->state != state) {
         finishSession(Error::UnexpectedElementError);
         return false;
     }
     return true;
 }
 
 void ClientSession::sendCredentials(const SafeByteArray& password) {
-    assert(WaitingForCredentials);
+    assert(state == State::WaitingForCredentials);
     assert(authenticator);
-    state = Authenticating;
+    state = State::Authenticating;
     authenticator->setCredentials(localJID.getNode(), password);
     stream->writeElement(std::make_shared<AuthRequest>(authenticator->getName(), authenticator->getResponse()));
 }
 
 void ClientSession::handleTLSEncrypted() {
-    CHECK_STATE_OR_RETURN(Encrypting);
+    CHECK_STATE_OR_RETURN(State::Encrypting);
 
     std::vector<Certificate::ref> certificateChain = stream->getPeerCertificateChain();
     std::shared_ptr<CertificateVerificationError> verificationError = stream->getPeerCertificateVerificationError();
     if (verificationError) {
         checkTrustOrFinish(certificateChain, verificationError);
     }
     else {
         ServerIdentityVerifier identityVerifier(localJID, idnConverter);
         if (!certificateChain.empty() && identityVerifier.certificateVerifies(certificateChain[0])) {
             continueAfterTLSEncrypted();
         }
         else {
             checkTrustOrFinish(certificateChain, std::make_shared<CertificateVerificationError>(CertificateVerificationError::InvalidServerIdentity));
         }
     }
 }
 
 void ClientSession::checkTrustOrFinish(const std::vector<Certificate::ref>& certificateChain, std::shared_ptr<CertificateVerificationError> error) {
     if (certificateTrustChecker && certificateTrustChecker->isCertificateTrusted(certificateChain)) {
         continueAfterTLSEncrypted();
     }
     else {
         finishSession(error);
     }
 }
 
+void ClientSession::initiateShutdown(bool sendFooter) {
+    if (!streamShutdownTimeout) {
+        streamShutdownTimeout = timerFactory->createTimer(sessionShutdownTimeoutInMilliseconds);
+        streamShutdownTimeout->onTick.connect(boost::bind(&ClientSession::handleStreamShutdownTimeout, shared_from_this()));
+        streamShutdownTimeout->start();
+    }
+    if (sendFooter) {
+        stream->writeFooter();
+    }
+    if (state == State::Finishing) {
+        // The other side already send </stream>; we can close the socket.
+        stream->close();
+    }
+    else {
+        state = State::Finishing;
+    }
+}
+
 void ClientSession::continueAfterTLSEncrypted() {
-    state = WaitingForStreamStart;
+    state = State::WaitingForStreamStart;
     stream->resetXMPPParser();
     sendStreamHeader();
 }
 
 void ClientSession::handleStreamClosed(std::shared_ptr<Swift::Error> streamError) {
     State previousState = state;
-    state = Finished;
+    state = State::Finished;
+
+    if (streamShutdownTimeout) {
+        streamShutdownTimeout->stop();
+        streamShutdownTimeout.reset();
+    }
 
     if (stanzaAckRequester_) {
         stanzaAckRequester_->onRequestAck.disconnect(boost::bind(&ClientSession::requestAck, shared_from_this()));
         stanzaAckRequester_->onStanzaAcked.disconnect(boost::bind(&ClientSession::handleStanzaAcked, shared_from_this(), _1));
         stanzaAckRequester_.reset();
     }
     if (stanzaAckResponder_) {
         stanzaAckResponder_->onAck.disconnect(boost::bind(&ClientSession::ack, shared_from_this(), _1));
         stanzaAckResponder_.reset();
     }
     stream->setWhitespacePingEnabled(false);
     stream->onStreamStartReceived.disconnect(boost::bind(&ClientSession::handleStreamStart, shared_from_this(), _1));
+    stream->onStreamEndReceived.disconnect(boost::bind(&ClientSession::handleStreamEnd, shared_from_this()));
     stream->onElementReceived.disconnect(boost::bind(&ClientSession::handleElement, shared_from_this(), _1));
     stream->onClosed.disconnect(boost::bind(&ClientSession::handleStreamClosed, shared_from_this(), _1));
     stream->onTLSEncrypted.disconnect(boost::bind(&ClientSession::handleTLSEncrypted, shared_from_this()));
 
-    if (previousState == Finishing) {
+    if (previousState == State::Finishing) {
         onFinished(error_);
     }
     else {
         onFinished(streamError);
     }
 }
 
+void ClientSession::handleStreamShutdownTimeout() {
+    handleStreamClosed(std::shared_ptr<Swift::Error>());
+}
+
 void ClientSession::finish() {
-    finishSession(std::shared_ptr<Error>());
+    if (state != State::Finishing && state != State::Finished) {
+        finishSession(std::shared_ptr<Error>());
+    }
+    else {
+        SWIFT_LOG(warning) << "Session already finished or finishing." << std::endl;
+    }
 }
 
 void ClientSession::finishSession(Error::Type error) {
     finishSession(std::make_shared<Swift::ClientSession::Error>(error));
 }
 
 void ClientSession::finishSession(std::shared_ptr<Swift::Error> error) {
-    state = Finishing;
     if (!error_) {
         error_ = error;
     }
     else {
         SWIFT_LOG(warning) << "Session finished twice";
     }
     assert(stream->isOpen());
     if (stanzaAckResponder_) {
         stanzaAckResponder_->handleAckRequestReceived();
     }
     if (authenticator) {
         delete authenticator;
         authenticator = nullptr;
     }
-    stream->writeFooter();
-    stream->close();
+    // Immidiately close TCP connection without stream closure.
+    if (std::dynamic_pointer_cast<CertificateVerificationError>(error)) {
+        state = State::Finishing;
+        initiateShutdown(false);
+    }
+    else {
+        if (state == State::Finishing) {
+            initiateShutdown(true);
+        }
+        else if (state != State::Finished) {
+            initiateShutdown(true);
+        }
+    }
 }
 
 void ClientSession::requestAck() {
     stream->writeElement(std::make_shared<StanzaAckRequest>());
 }
 
 void ClientSession::handleStanzaAcked(std::shared_ptr<Stanza> stanza) {
     onStanzaAcked(stanza);
 }
 
 void ClientSession::ack(unsigned int handledStanzasCount) {
     stream->writeElement(std::make_shared<StanzaAck>(handledStanzasCount));
 }
 
 }