Fix bug in qsslsocket peek()

Calling peek() for qsslsocket caused socket data to be copied into
qiodevices buffer and therefore make it unaccessible in qsslsocket.

Cherry picked form 4.8-branch & modified to Qt5 API changes
(int -> qintptr)
Original commits:
commit 621f18955082fc73471e75d1f8c35c2dcd4befeb
Author: Shane Kearns <ext-shane.2.kearns@nokia.com>
commit 68b1d5c17aa38d5921bdade2b0e0cb67c6c90513
Author: Kalle Viironen <kalle.viironen@digia.com>

Task-number: QTBUG-18498
Change-Id: I6be4b19baec2f3197537f5e7b61432040ec84ad2
Reviewed-by: Shane Kearns <shane.kearns@accenture.com>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

2 files changed, 54 insertions, 0 deletions

diff --git a/src/network/ssl/qsslsocket.cpp b/src/network/ssl/qsslsocket.cpp
index 6338cbbe6f..27c0123fbd 100644
--- a/src/network/ssl/qsslsocket.cpp
+++ b/src/network/ssl/qsslsocket.cpp
@@ -2332,6 +2332,57 @@ bool QSslSocketPrivate::verifyErrorsHaveBeenIgnored()
 /*!
     \internal
 */
+qint64 QSslSocketPrivate::peek(char *data, qint64 maxSize)
+{
+    if (mode == QSslSocket::UnencryptedMode && !autoStartHandshake) {
+        //unencrypted mode - do not use QIODevice::peek, as it reads ahead data from the plain socket
+        //peek at data already in the QIODevice buffer (from a previous read)
+        qint64 r = buffer.peek(data, maxSize);
+        if (r == maxSize)
+            return r;
+        data += r;
+        //peek at data in the plain socket
+        if (plainSocket) {
+            qint64 r2 = plainSocket->peek(data, maxSize - r);
+            if (r2 < 0)
+                return (r > 0 ? r : r2);
+            return r + r2;
+        } else {
+            return -1;
+        }
+    } else {
+        //encrypted mode - the socket engine will read and decrypt data into the QIODevice buffer
+        return QTcpSocketPrivate::peek(data, maxSize);
+    }
+}
+
+/*!
+    \internal
+*/
+QByteArray QSslSocketPrivate::peek(qint64 maxSize)
+{
+    if (mode == QSslSocket::UnencryptedMode && !autoStartHandshake) {
+        //unencrypted mode - do not use QIODevice::peek, as it reads ahead data from the plain socket
+        //peek at data already in the QIODevice buffer (from a previous read)
+        QByteArray ret;
+        ret.reserve(maxSize);
+        ret.resize(buffer.peek(ret.data(), maxSize));
+        if (ret.length() == maxSize)
+            return ret;
+        //peek at data in the plain socket
+        if (plainSocket)
+            return ret + plainSocket->peek(maxSize - ret.length());
+        else
+            return QByteArray();
+    } else {
+        //encrypted mode - the socket engine will read and decrypt data into the QIODevice buffer
+        return QTcpSocketPrivate::peek(maxSize);
+    }
+}
+
+/*!
+    \internal
+*/
 QList<QByteArray> QSslSocketPrivate::unixRootCertDirectories()
 {
     return QList<QByteArray>() <<  "/etc/ssl/certs/" // (K)ubuntu, OpenSUSE, Mandriva, MeeGo ...
diff --git a/src/network/ssl/qsslsocket_p.h b/src/network/ssl/qsslsocket_p.h
index ff51628511..3b97b5da6d 100644
--- a/src/network/ssl/qsslsocket_p.h
+++ b/src/network/ssl/qsslsocket_p.h
@@ -166,6 +166,9 @@ public:
     virtual void _q_caRootLoaded(QSslCertificate,QSslCertificate) = 0;
 #endif
 
+    virtual qint64 peek(char *data, qint64 maxSize);
+    virtual QByteArray peek(qint64 maxSize);
+
     // Platform specific functions
     virtual void startClientEncryption() = 0;
     virtual void startServerEncryption() = 0;