Add support for finding the version of SSL/TLS in use.

Previously we allowed you to specify which version(s) you wanted to use,
but did not provide access to the version that was actually negotiated.

[ChangeLog][QtNetwork][QSslSocket] Add support for finding the version
of SSL/TLS in use by a connection.

Task-number: QTBUG-28471
Change-Id: I6d50d2bc9f1ce7f98192e67992178fe7e41c0575
Reviewed-by: Peter Hartmann <phartmann@blackberry.com>

src/network/ssl/qsslconfiguration.cpp

@@ -208,6 +208,7 @@ bool QSslConfiguration::operator==(const QSslConfiguration &other) const
         d->localCertificateChain == other.d->localCertificateChain &&
         d->privateKey == other.d->privateKey &&
         d->sessionCipher == other.d->sessionCipher &&
+        d->sessionProtocol == other.d->sessionProtocol &&
         d->ciphers == other.d->ciphers &&
         d->caCertificates == other.d->caCertificates &&
         d->protocol == other.d->protocol &&
@@ -511,6 +512,18 @@ QSslCipher QSslConfiguration::sessionCipher() const
     return d->sessionCipher;
 }
 
+/*!
+    Returns the socket's SSL/TLS protocol or UnknownProtocol if the
+    connection isn't encrypted. The socket's protocol for the session
+    is set during the handshake phase.
+
+    \sa protocol(), setProtocol()
+*/
+QSsl::SslProtocol QSslConfiguration::sessionProtocol() const
+{
+    return d->sessionProtocol;
+}
+
 /*!
     Returns the \l {QSslKey} {SSL key} assigned to this connection or
     a null key if none has been assigned yet.

src/network/ssl/qsslconfiguration.h

@@ -109,6 +109,7 @@ public:
     QSslCertificate peerCertificate() const;
     QList<QSslCertificate> peerCertificateChain() const;
     QSslCipher sessionCipher() const;
+    QSsl::SslProtocol sessionProtocol() const;
 
     // Private keys, for server sockets
     QSslKey privateKey() const;

src/network/ssl/qsslconfiguration_p.h

@@ -81,7 +81,8 @@ class QSslConfigurationPrivate: public QSharedData
 {
 public:
     QSslConfigurationPrivate()
-        : protocol(QSsl::SecureProtocols),
+        : sessionProtocol(QSsl::UnknownProtocol),
+          protocol(QSsl::SecureProtocols),
           peerVerifyMode(QSslSocket::AutoVerifyPeer),
           peerVerifyDepth(0),
           allowRootCertOnDemandLoading(true),
@@ -98,6 +99,7 @@ public:
 
     QSslKey privateKey;
     QSslCipher sessionCipher;
+    QSsl::SslProtocol sessionProtocol;
     QList<QSslCipher> ciphers;
     QList<QSslCertificate> caCertificates;
 

src/network/ssl/qsslsocket.cpp

@@ -878,6 +878,7 @@ QSslConfiguration QSslSocket::sslConfiguration() const
     QSslConfigurationPrivate *copy = new QSslConfigurationPrivate(d->configuration);
     copy->ref.store(0);              // the QSslConfiguration constructor refs up
     copy->sessionCipher = d->sessionCipher();
+    copy->sessionProtocol = d->sessionProtocol();
 
     return QSslConfiguration(copy);
 }
@@ -1072,6 +1073,20 @@ QSslCipher QSslSocket::sessionCipher() const
     return d->sessionCipher();
 }
 
+/*!
+    Returns the socket's SSL/TLS protocol or UnknownProtocol if the
+    connection isn't encrypted. The socket's protocol for the session
+    is set during the handshake phase.
+
+    \sa protocol(), setProtocol()
+*/
+QSsl::SslProtocol QSslSocket::sessionProtocol() const
+{
+    Q_D(const QSslSocket);
+    return d->sessionProtocol();
+}
+
+
 /*!
     Sets the socket's private \l {QSslKey} {key} to \a key. The
     private key and the local \l {QSslCertificate} {certificate} are
@@ -2095,6 +2110,7 @@ void QSslConfigurationPrivate::deepCopyDefaultConfiguration(QSslConfigurationPri
     ptr->localCertificateChain = global->localCertificateChain;
     ptr->privateKey = global->privateKey;
     ptr->sessionCipher = global->sessionCipher;
+    ptr->sessionProtocol = global->sessionProtocol;
     ptr->ciphers = global->ciphers;
     ptr->caCertificates = global->caCertificates;
     ptr->protocol = global->protocol;

src/network/ssl/qsslsocket.h

@@ -140,6 +140,7 @@ public:
     QSslCertificate peerCertificate() const;
     QList<QSslCertificate> peerCertificateChain() const;
     QSslCipher sessionCipher() const;
+    QSsl::SslProtocol sessionProtocol() const;
 
     // Private keys, for server sockets.
     void setPrivateKey(const QSslKey &key);

src/network/ssl/qsslsocket_openssl.cpp

@@ -1428,6 +1428,28 @@ QSslCipher QSslSocketBackendPrivate::sessionCipher() const
     return sessionCipher ? QSslCipher_from_SSL_CIPHER(sessionCipher) : QSslCipher();
 }
 
+QSsl::SslProtocol QSslSocketBackendPrivate::sessionProtocol() const
+{
+    if (!ssl)
+        return QSsl::UnknownProtocol;
+    int ver = q_SSL_version(ssl);
+
+    switch (ver) {
+    case 0x2:
+        return QSsl::SslV2;
+    case 0x300:
+        return QSsl::SslV3;
+    case 0x301:
+        return QSsl::TlsV1_0;
+    case 0x302:
+        return QSsl::TlsV1_1;
+    case 0x303:
+        return QSsl::TlsV1_2;
+    }
+
+    return QSsl::UnknownProtocol;
+}
+
 void QSslSocketBackendPrivate::continueHandshake()
 {
     Q_Q(QSslSocket);

src/network/ssl/qsslsocket_openssl_p.h

@@ -131,6 +131,7 @@ public:
     void disconnectFromHost();
     void disconnected();
     QSslCipher sessionCipher() const;
+    QSsl::SslProtocol sessionProtocol() const;
     void continueHandshake();
     bool checkSslErrors();
 #ifdef Q_OS_WIN

src/network/ssl/qsslsocket_openssl_symbols.cpp

@@ -238,6 +238,7 @@ DEFINEFUNC(const SSL_CIPHER *, SSL_get_current_cipher, SSL *a, a, return 0, retu
 #else
 DEFINEFUNC(SSL_CIPHER *, SSL_get_current_cipher, SSL *a, a, return 0, return)
 #endif
+DEFINEFUNC(int, SSL_version, const SSL *a, a, return 0, return)
 DEFINEFUNC2(int, SSL_get_error, SSL *a, a, int b, b, return -1, return)
 DEFINEFUNC(STACK_OF(X509) *, SSL_get_peer_cert_chain, SSL *a, a, return 0, return)
 DEFINEFUNC(X509 *, SSL_get_peer_certificate, SSL *a, a, return 0, return)
@@ -739,6 +740,7 @@ bool q_resolveOpenSslSymbols()
     RESOLVEFUNC(SSL_free)
     RESOLVEFUNC(SSL_get_ciphers)
     RESOLVEFUNC(SSL_get_current_cipher)
+    RESOLVEFUNC(SSL_version)
     RESOLVEFUNC(SSL_get_error)
     RESOLVEFUNC(SSL_get_peer_cert_chain)
     RESOLVEFUNC(SSL_get_peer_certificate)

src/network/ssl/qsslsocket_openssl_symbols_p.h

@@ -329,6 +329,7 @@ const SSL_CIPHER *q_SSL_get_current_cipher(SSL *a);
 #else
 SSL_CIPHER *q_SSL_get_current_cipher(SSL *a);
 #endif
+int q_SSL_version(const SSL *a);
 int q_SSL_get_error(SSL *a, int b);
 STACK_OF(X509) *q_SSL_get_peer_cert_chain(SSL *a);
 X509 *q_SSL_get_peer_certificate(SSL *a);

src/network/ssl/qsslsocket_p.h

@@ -190,6 +190,7 @@ public:
     virtual void disconnectFromHost() = 0;
     virtual void disconnected() = 0;
     virtual QSslCipher sessionCipher() const = 0;
+    virtual QSsl::SslProtocol sessionProtocol() const = 0;
     virtual void continueHandshake() = 0;
 
     Q_AUTOTEST_EXPORT static bool rootCertOnDemandLoadingSupported();