cryptdata.cpp

/*
 * Copyright (C) 2014 Red Hat
 *
 * This file is part of openconnect-gui.
 *
 * openconnect-gui is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "cryptdata.h"
#include <QByteArray>

#if defined(_WIN32)
#include <windows.h>
#include <winbase.h>

typedef WINBOOL(WINAPI * CryptProtectDataFunc) (DATA_BLOB * pDataIn,
                                                LPCWSTR szDataDescr,
                                                DATA_BLOB * pOptionalEntropy,
                                                PVOID pvReserved,
                                                CRYPTPROTECT_PROMPTSTRUCT *
                                                pPromptStruct, DWORD dwFlags,
                                                DATA_BLOB * pDataOut);
typedef WINBOOL(WINAPI * CryptUnprotectDataFunc) (DATA_BLOB * pDataIn,
                                                  LPWSTR * ppszDataDescr,
                                                  DATA_BLOB * pOptionalEntropy,
                                                  PVOID pvReserved,
                                                  CRYPTPROTECT_PROMPTSTRUCT *
                                                  pPromptStruct, DWORD dwFlags,
                                                  DATA_BLOB * pDataOut);

static CryptProtectDataFunc pCryptProtectData;
static CryptUnprotectDataFunc pCryptUnprotectData;
static int lib_init = 0;

static void __attribute__ ((constructor)) init(void)
{
    static HMODULE lib;
    lib = LoadLibraryA("crypt32.dll");
    if (lib == NULL)
        return;

    pCryptProtectData =
        (CryptProtectDataFunc) GetProcAddress(lib, "CryptProtectData");
    pCryptUnprotectData =
        (CryptUnprotectDataFunc) GetProcAddress(lib, "CryptUnprotectData");
    if (pCryptProtectData == NULL || pCryptUnprotectData == NULL) {
        FreeLibrary(lib);
        return;
    }
    lib_init = 1;
}

QByteArray CryptData::encode(QString & txt, QString password)
{
    BOOL r;
    DATA_BLOB DataIn;
    DATA_BLOB Opt;
    DATA_BLOB DataOut;
    QByteArray res, data;

    if (lib_init == 0)
        return password.toUtf8();

    DataIn.pbData = (BYTE *) password.toUtf8().data();
    DataIn.cbData = password.toUtf8().size();

    Opt.pbData = (BYTE *) txt.toUtf8().data();
    Opt.cbData = txt.toUtf8().size();

    r = pCryptProtectData(&DataIn, NULL, &Opt, NULL, NULL, 0, &DataOut);
    if (r == false)
        return res;

    data.setRawData((const char *)DataOut.pbData, DataOut.cbData);

    res.clear();
    res.append("xxxx");
    res.append(data.toBase64());

    LocalFree(DataOut.pbData);
    return res;
}

bool CryptData::decode(QString & txt, QByteArray _enc, QString & res)
{
    BOOL r;
    DATA_BLOB DataIn;
    DATA_BLOB Opt;
    DATA_BLOB DataOut;
    QByteArray enc;

    res.clear();

    if (lib_init == 0 || _enc.startsWith("xxxx") == false) {
        res = QString::fromUtf8(_enc);
        return true;
    }

    enc = QByteArray::fromBase64(_enc.mid(4));

    DataIn.pbData = (BYTE *) enc.data();
    DataIn.cbData = enc.size();

    Opt.pbData = (BYTE *) txt.toAscii().data();
    Opt.cbData = txt.toAscii().size();

    r = pCryptUnprotectData(&DataIn, NULL, &Opt, NULL, NULL, 0, &DataOut);
    if (r == false)
        return false;

    res = QString::fromUtf8((const char *)DataOut.pbData, DataOut.cbData);
    LocalFree(DataOut.pbData);
    return true;
}

#else

QByteArray CryptData::encode(QString & txt, QString password)
{
    return password.toUtf8();
}

bool CryptData::decode(QString & txt, QByteArray _enc, QString & res)
{
    res = QString::fromUtf8(_enc);
    return true;
}

#endif