Decode ASCII encoded SSID names

This patch adds a decodeHexEncoded() utility function
for decoding wpa_supplicant's hex encoded strings.

Task-number: QTEE-817
Change-Id: I257a8892cdc48ce285561fd879b8a9ab0a50bfc4
Reviewed-by: Laszlo Agocs <laszlo.agocs@theqtcompany.com>

6 files changed, 194 insertions, 15 deletions

diff --git a/src/wifi/qwificontroller.cpp b/src/wifi/qwificontroller.cpp
index 2c6baac..f63b554 100644
--- a/src/wifi/qwificontroller.cpp
+++ b/src/wifi/qwificontroller.cpp
@@ -33,7 +33,7 @@
 
 #ifdef Q_OS_ANDROID_NO_SDK
 /*
- * Work API differences between Android versions
+ * Workaround API differences between Android versions
  */
 int q_wifi_start_supplicant()
 {
diff --git a/src/wifi/qwifimanager.cpp b/src/wifi/qwifimanager.cpp
index bc236f2..319c9d9 100644
--- a/src/wifi/qwifimanager.cpp
+++ b/src/wifi/qwifimanager.cpp
@@ -20,6 +20,8 @@
 #include "qwifinetworklistmodel_p.h"
 #include "qwifinetwork_p.h"
 #include "qwifimanager_p.h"
+#include "qwifiutils_p.h"
+
 #include "qwifidevice.h"
 
 #include <QtCore/QFile>
@@ -98,7 +100,7 @@ void QWifiManagerPrivate::handleConnected()
     if (connectedNetwork.isEmpty())
         return;
 
-    m_currentSSID = connectedNetwork.split('\t').at(1);
+    m_currentSSID = QWifiUtils::decodeHexEncoded(connectedNetwork.split('\t').at(1));
     qCDebug(B2QT_WIFI) << "connected network: " << m_currentSSID;
     updateNetworkState(QWifiManager::ObtainingIPAddress);
     m_wifiController->call(QWifiController::AcquireIPAddress);
@@ -167,20 +169,21 @@ QString QWifiManagerPrivate::call(const QString &command)
     actualCommand.prepend(prefix);
 #endif
 #endif
-    if (q_wifi_command(m_interface, actualCommand.toLatin1(), data, &len) < 0) {
-        qCDebug(B2QT_WIFI) << "call to supplicant failed: " << actualCommand;
+    qCDebug(B2QT_WIFI) << "call command: " << actualCommand.toLocal8Bit();
+    if (q_wifi_command(m_interface, actualCommand.toLocal8Bit(), data, &len) < 0) {
+        qCDebug(B2QT_WIFI) << "call to supplicant failed!";
         return QString();
     }
     if (len < sizeof(data))
         data[len] = 0;
 
     QString result = QLatin1String(data);
-    return result;
+    return result.trimmed();
 }
 
 bool QWifiManagerPrivate::checkedCall(const QString &command)
 {
-    return call(command).trimmed().toUpper() == QLatin1String("OK");
+    return call(command).toUpper() == QLatin1String("OK");
 }
 
 void QWifiManagerPrivate::updateLastError(const QString &error)
@@ -472,11 +475,12 @@ bool QWifiManager::connect(QWifiConfiguration *config)
     d->m_currentSSID = config->ssid();
     bool networkKnown = false;
     QString id;
-    QString listResult = d->call(QStringLiteral("LIST_NETWORKS"));
-    QStringList lines = listResult.split('\n');
-    foreach (const QString &line, lines) {
-        if (line.contains(d->m_currentSSID)) {
-            id = line.split('\t').at(0);
+    const QStringList configuredNetworks = d->call(QStringLiteral("LIST_NETWORKS")).split('\n');
+    for (int i = 1; i < configuredNetworks.length(); ++i) {
+        const QStringList networkFields = configuredNetworks.at(i).split('\t');
+        const QString ssid = QWifiUtils::decodeHexEncoded(networkFields.at(1));
+        if (ssid == d->m_currentSSID) {
+            id = networkFields.at(0);
             networkKnown = true;
             break;
         }
@@ -484,7 +488,7 @@ bool QWifiManager::connect(QWifiConfiguration *config)
 
     if (!networkKnown) {
         bool ok;
-        id = d->call(QStringLiteral("ADD_NETWORK")).trimmed();
+        id = d->call(QStringLiteral("ADD_NETWORK"));
         id.toInt(&ok);
         if (!ok) {
             d->updateLastError(QStringLiteral("failed to add network!"));
diff --git a/src/wifi/qwifinetworklistmodel.cpp b/src/wifi/qwifinetworklistmodel.cpp
index 6f53295..e562b2b 100644
--- a/src/wifi/qwifinetworklistmodel.cpp
+++ b/src/wifi/qwifinetworklistmodel.cpp
@@ -18,6 +18,7 @@
 ****************************************************************************/
 #include "qwifinetworklistmodel_p.h"
 #include "qwifinetwork_p.h"
+#include "qwifiutils_p.h"
 
 #include "qwifimanager.h"
 
@@ -123,7 +124,7 @@ void QWifiNetworkListModel::parseScanResults(const QString &results)
             continue;
         int pos = 0;
 
-        QString ssid = info.at(4);
+        QString ssid = QWifiUtils::decodeHexEncoded(info.at(4));
         sensibleNetworks.insert(ssid);
         QWifiNetwork *knownNetwork = networkForSSID(ssid, &pos);
         if (!knownNetwork)
diff --git a/src/wifi/qwifiutils.cpp b/src/wifi/qwifiutils.cpp
new file mode 100644
index 0000000..21c440b
--- /dev/null
+++ b/src/wifi/qwifiutils.cpp
@@ -0,0 +1,135 @@
+/****************************************************************************
+**
+** Copyright (C) 2015 Digia Plc
+** All rights reserved.
+** For any questions to Digia, please use the contact form at
+** http://www.qt.io
+**
+** This file is part of Qt Enterprise Embedded.
+**
+** Licensees holding valid Qt Enterprise licenses may use this file in
+** accordance with the Qt Enterprise License Agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and Digia.
+**
+** If you have questions regarding the use of this file, please use
+** the contact form at http://www.qt.io
+**
+****************************************************************************/
+#include "qwifiutils_p.h"
+
+QT_BEGIN_NAMESPACE
+
+int QWifiUtils::hex2num(char c)
+{
+    if (c >= '0' && c <= '9')
+        return c - '0';
+    if (c >= 'a' && c <= 'f')
+        return c - 'a' + 10;
+    if (c >= 'A' && c <= 'F')
+        return c - 'A' + 10;
+    return -1;
+}
+
+int QWifiUtils::hex2byte(const char *hex)
+{
+    int a, b;
+    a = hex2num(*hex++);
+    if (a < 0)
+        return -1;
+    b = hex2num(*hex++);
+    if (b < 0)
+        return -1;
+    return (a << 4) | b;
+}
+
+// the logic of this function is taken from wpa_supplicant source code (BSD
+// licensed code) see http://w1.fi/cgit file hostapd/src/utils/common.c
+// For Ascii encoded string, any octet < 32 or > 127 is encoded as a "\x"
+// followed by the hex representation of the octet. Exception chars are ",
+// \, \e, \n, \r, \t which are escaped by a backslash
+QString QWifiUtils::decodeHexEncoded(const QString &encoded)
+{
+    int maxlen = encoded.size() + 1;
+    QByteArray buf;
+    buf.resize(maxlen);
+    const char *pos = encoded.toLocal8Bit().constData();
+    int len = 0;
+    int val;
+
+    while (*pos) {
+        if (len + 1 >= maxlen)
+            break;
+        switch (*pos) {
+        case '\\':
+            pos++;
+            switch (*pos) {
+            case '\\':
+                buf[len++] = '\\';
+                pos++;
+                break;
+            case '"':
+                buf[len++] = '"';
+                pos++;
+                break;
+            case 'n':
+                buf[len++] = '\n';
+                pos++;
+                break;
+            case 'r':
+                buf[len++] = '\r';
+                pos++;
+                break;
+            case 't':
+                buf[len++] = '\t';
+                pos++;
+                break;
+            case 'e':
+                buf[len++] = '\033';
+                pos++;
+                break;
+            case 'x':
+                pos++;
+                val = hex2byte(pos);
+                if (val < 0) {
+                    val = hex2num(*pos);
+                    if (val < 0)
+                        break;
+                    buf[len++] = val;
+                    pos++;
+                } else {
+                    buf[len++] = val;
+                    pos += 2;
+                }
+                break;
+            case '0':
+            case '1':
+            case '2':
+            case '3':
+            case '4':
+            case '5':
+            case '6':
+            case '7':
+                val = *pos++ - '0';
+                if (*pos >= '0' && *pos <= '7')
+                    val = val * 8 + (*pos++ - '0');
+                if (*pos >= '0' && *pos <= '7')
+                    val = val * 8 + (*pos++ - '0');
+                buf[len++] = val;
+                break;
+            default:
+                break;
+            }
+            break;
+        default:
+            buf[len++] = *pos++;
+            break;
+        }
+    }
+    if (maxlen > len)
+        buf[len] = '\0';
+
+    return QString::fromUtf8(buf);
+}
+
+QT_END_NAMESPACE
diff --git a/src/wifi/qwifiutils_p.h b/src/wifi/qwifiutils_p.h
new file mode 100644
index 0000000..8b3e54a
--- /dev/null
+++ b/src/wifi/qwifiutils_p.h
@@ -0,0 +1,37 @@
+/****************************************************************************
+**
+** Copyright (C) 2015 Digia Plc
+** All rights reserved.
+** For any questions to Digia, please use the contact form at
+** http://www.qt.io
+**
+** This file is part of Qt Enterprise Embedded.
+**
+** Licensees holding valid Qt Enterprise licenses may use this file in
+** accordance with the Qt Enterprise License Agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and Digia.
+**
+** If you have questions regarding the use of this file, please use
+** the contact form at http://www.qt.io
+**
+****************************************************************************/
+#ifndef QWIFIUTILS_H
+#define QWIFIUTILS_H
+
+#include <QtCore/QString>
+
+QT_BEGIN_NAMESPACE
+
+class QWifiUtils
+{
+public:
+    static int hex2num(char c);
+    static int hex2byte(const char *hex);
+
+    static QString decodeHexEncoded(const QString &encoded);
+};
+
+QT_END_NAMESPACE
+
+#endif // QWIFIUTILS_H
diff --git a/src/wifi/wifi.pro b/src/wifi/wifi.pro
index e558081..f248774 100644
--- a/src/wifi/wifi.pro
+++ b/src/wifi/wifi.pro
@@ -16,7 +16,8 @@ HEADERS += \
     $$PWD/qwifinetworklistmodel_p.h \
     $$PWD/qwificontroller_p.h \
     $$PWD/qwifidevice.h \
-    $$PWD/qwificonfiguration.h
+    $$PWD/qwificonfiguration.h \
+    $$PWD/qwifiutils_p.h
 
 SOURCES += \
     $$PWD/qwifimanager.cpp \
@@ -24,7 +25,8 @@ SOURCES += \
     $$PWD/qwifinetworklistmodel.cpp \
     $$PWD/qwificontroller.cpp \
     $$PWD/qwifidevice.cpp \
-    $$PWD/qwificonfiguration.cpp
+    $$PWD/qwificonfiguration.cpp \
+    $$PWD/qwifiutils.cpp
 
 android: {
     LIBS += -lhardware_legacy -lcutils