Stream: Add IQ response sender check

Verifies that the sender of the response is correct, so no evil entity
can inject responses.

Fixes #510.

3 files changed, 18 insertions, 4 deletions

diff --git a/src/client/QXmppClient.cpp b/src/client/QXmppClient.cpp
index 174c4219..a6d55fa8 100644
--- a/src/client/QXmppClient.cpp
+++ b/src/client/QXmppClient.cpp
@@ -517,12 +517,12 @@ QFuture<QXmppClient::IqResult> QXmppClient::sendIq(QXmppIq &&iq, const std::opti
 ///
 QFuture<QXmppClient::IqResult> QXmppClient::sendSensitiveIq(QXmppIq &&iq, const std::optional<QXmppSendStanzaParams> &params)
 {
-    const auto sendEncrypted = [this](QFuture<IqEncryptResult> &&future, const QString &id) {
+    const auto sendEncrypted = [this](QFuture<IqEncryptResult> &&future, const QString &id, const QString &to) {
         QFutureInterface<IqResult> interface(QFutureInterfaceBase::Started);
-        await(future, this, [this, interface, id](IqEncryptResult result) mutable {
+        await(future, this, [this, interface, id, to](IqEncryptResult result) mutable {
             if (const auto *xml = std::get_if<QByteArray>(&result)) {
                 // encrypted successfully
-                auto future = d->stream->sendIq(QXmppPacket(*xml, true), id);
+                auto future = d->stream->QXmppStream::sendIq(QXmppPacket(*xml, true), id, to);
                 await(future, this, [this, interface](QXmppStream::IqResult result) mutable {
                     if (const auto encryptedDom = std::get_if<QDomElement>(&result)) {
                         if (!isIqResponse(*encryptedDom)) {
@@ -571,10 +571,13 @@ QFuture<QXmppClient::IqResult> QXmppClient::sendSensitiveIq(QXmppIq &&iq, const
     if (iq.id().isEmpty() || d->stream->hasIqId(iq.id())) {
         iq.setId(QXmppUtils::generateStanzaUuid());
     }
+    if (iq.to().isEmpty()) {
+        iq.setTo(d->stream->configuration().domain());
+    }
 
     if (d->encryptionExtension) {
         const auto id = iq.id();
-        return sendEncrypted(d->encryptionExtension->encryptIq(std::move(iq), params), id);
+        return sendEncrypted(d->encryptionExtension->encryptIq(std::move(iq), params), id, iq.to());
     }
     return d->stream->sendIq(std::move(iq));
 }
diff --git a/src/client/QXmppOutgoingClient.cpp b/src/client/QXmppOutgoingClient.cpp
index 7d1ad6a3..9a8e51b8 100644
--- a/src/client/QXmppOutgoingClient.cpp
+++ b/src/client/QXmppOutgoingClient.cpp
@@ -19,6 +19,7 @@
 
 #include <QCryptographicHash>
 #include <QDnsLookup>
+#include <QFuture>
 #include <QNetworkProxy>
 #include <QSslConfiguration>
 #include <QSslSocket>
@@ -316,6 +317,15 @@ bool QXmppOutgoingClient::isStreamResumed() const
     return d->streamResumed;
 }
 
+QFuture<QXmppStream::IqResult> QXmppOutgoingClient::sendIq(QXmppIq &&iq)
+{
+    // always set a to address (the QXmppStream needs this for matching)
+    if (iq.to().isEmpty()) {
+        iq.setTo(d->config.domain());
+    }
+    return QXmppStream::sendIq(std::move(iq));
+}
+
 void QXmppOutgoingClient::_q_socketDisconnected()
 {
     debug("Socket disconnected");
diff --git a/src/client/QXmppOutgoingClient.h b/src/client/QXmppOutgoingClient.h
index 57e3477a..6c72d076 100644
--- a/src/client/QXmppOutgoingClient.h
+++ b/src/client/QXmppOutgoingClient.h
@@ -38,6 +38,7 @@ public:
     bool isClientStateIndicationEnabled() const;
     bool isStreamManagementEnabled() const;
     bool isStreamResumed() const;
+    QFuture<IqResult> sendIq(QXmppIq &&);
 
     /// Returns the used socket
     QSslSocket *socket() const { return QXmppStream::socket(); };