Refactor WLAN PSK retrieval code

- Reduce platform specific code in ImageWriter class,
  and move that to seperate classes.
- Use API calls to get current SSID on Windows and Linux instead
  of launching command line utilities.

src/windows/winwlancredentials.cpp

@@ -0,0 +1,140 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ * Copyright (C) 2023 Raspberry Pi Ltd
+ */
+
+#include "winwlancredentials.h"
+#include <windows.h>
+#include <winioctl.h>
+#include <wlanapi.h>
+#include <Windot11.h>
+#include <QDebug>
+#include <QRegularExpression>
+#ifndef WLAN_PROFILE_GET_PLAINTEXT_KEY
+#define WLAN_PROFILE_GET_PLAINTEXT_KEY 4
+#endif
+
+inline QString unescapeXml(QString str)
+{
+    static const char *table[] = {
+        "&lt;", "<",
+        "&gt;", ">",
+        "&quot;", "\"",
+        "&apos;", "'",
+        "&amp;", "&"
+    };
+    int tableLen = sizeof(table) / sizeof(table[0]);
+
+    for (int i=0; i < tableLen; i+=2)
+    {
+        str.replace(table[i], table[i+1]);
+    }
+
+    return str;
+}
+
+WinWlanCredentials::WinWlanCredentials()
+{
+    /* Get both SSID and PSK in one go, and store it in variables */
+    HANDLE h;
+    DWORD supportedVersion = 0;
+    DWORD clientVersion = 2;
+
+    if (WlanOpenHandle(clientVersion, NULL, &supportedVersion, &h) != ERROR_SUCCESS)
+        return;
+
+    PWLAN_INTERFACE_INFO_LIST ifList = NULL;
+
+    if (WlanEnumInterfaces(h, NULL, &ifList) == ERROR_SUCCESS)
+    {
+        for (DWORD i=0; i < ifList->dwNumberOfItems; i++)
+        {
+            PWLAN_PROFILE_INFO_LIST profileList = NULL;
+
+            if (ifList->InterfaceInfo[i].isState != wlan_interface_state_connected)
+                continue; /* Wlan adapter not connected */
+
+            /* Get current connection info for SSID */
+            PWLAN_CONNECTION_ATTRIBUTES pConnectInfo = NULL;
+            DWORD connectInfoSize = sizeof(WLAN_CONNECTION_ATTRIBUTES);
+            WLAN_OPCODE_VALUE_TYPE opCode = wlan_opcode_value_type_invalid;
+
+            if (WlanQueryInterface(h, &ifList->InterfaceInfo[i].InterfaceGuid,
+                               wlan_intf_opcode_current_connection, NULL,
+                               &connectInfoSize, (PVOID *) &pConnectInfo, &opCode) != ERROR_SUCCESS || !pConnectInfo)
+            {
+                continue;
+            }
+
+            if (pConnectInfo->wlanAssociationAttributes.dot11Ssid.uSSIDLength)
+            {
+                _ssid = QByteArray((const char *) pConnectInfo->wlanAssociationAttributes.dot11Ssid.ucSSID,
+                                   pConnectInfo->wlanAssociationAttributes.dot11Ssid.uSSIDLength);
+            }
+            WlanFreeMemory(pConnectInfo);
+
+            if (_ssid.isEmpty())
+                continue;
+
+            if (WlanGetProfileList(h, &ifList->InterfaceInfo[i].InterfaceGuid,
+                                   NULL, &profileList) == ERROR_SUCCESS)
+            {
+                for (DWORD j=0; j < profileList->dwNumberOfItems; j++)
+                {
+                    QString s = QString::fromWCharArray(profileList->ProfileInfo[j].strProfileName);
+                    qDebug() << "Enumerating wlan profiles, SSID found:" << s << " looking for:" << _ssid;
+
+                    if (s == _ssid) {
+                        DWORD flags = WLAN_PROFILE_GET_PLAINTEXT_KEY;
+                        DWORD access = 0;
+                        DWORD ret = 0;
+                        LPWSTR xmlstr = NULL;
+
+                        if ( (ret = WlanGetProfile(h, &ifList->InterfaceInfo[i].InterfaceGuid, profileList->ProfileInfo[j].strProfileName,
+                                          NULL, &xmlstr, &flags, &access)) == ERROR_SUCCESS && xmlstr)
+                        {
+                            QString xml = QString::fromWCharArray(xmlstr);
+                            qDebug() << "XML wlan profile:" << xml;
+                            QRegularExpression rx("<keyMaterial>(.+)</keyMaterial>");
+                            QRegularExpressionMatch match = rx.match(xml);
+
+                            if (match.hasMatch()) {
+                                _psk = unescapeXml(match.captured(1)).toLatin1();
+                            }
+
+                            WlanFreeMemory(xmlstr);
+                            break;
+                        }
+                    }
+                }
+            }
+
+            if (profileList) {
+                WlanFreeMemory(profileList);
+            }
+        }
+    }
+
+    if (ifList)
+        WlanFreeMemory(ifList);
+    WlanCloseHandle(h, NULL);
+}
+
+QByteArray WinWlanCredentials::getSSID()
+{
+    return _ssid;
+}
+
+QByteArray WinWlanCredentials::getPSK()
+{
+    return _psk;
+}
+
+WlanCredentials *WlanCredentials::_instance = NULL;
+WlanCredentials *WlanCredentials::instance()
+{
+    if (!_instance)
+        _instance = new WinWlanCredentials();
+
+    return _instance;
+}

src/windows/winwlancredentials.h

@@ -0,0 +1,22 @@
+#ifndef WINWLANCREDENTIALS_H
+#define WINWLANCREDENTIALS_H
+
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ * Copyright (C) 2023 Raspberry Pi Ltd
+ */
+
+#include "wlancredentials.h"
+
+class WinWlanCredentials : public WlanCredentials
+{
+public:
+    WinWlanCredentials();
+    virtual QByteArray getSSID();
+    virtual QByteArray getPSK();
+
+protected:
+    QByteArray _ssid, _psk;
+};
+
+#endif // WINWLANCREDENTIALS_H