git.maemo.org Git - keepassx/blob - src/lib/random.cpp

   1 /***************************************************************************
   2  *   Copyright (C) 2005 by Tarek Saidi                                     *
   3  *   mail@tarek-saidi.de                                                   *
   4  *                                                                         *
   5  *   This program is free software; you can redistribute it and/or modify  *
   6  *   it under the terms of the GNU General Public License as published by  *
   7  *   the Free Software Foundation; version 2 of the License.               *
   8
   9  *                                                                         *
  10  *   This program is distributed in the hope that it will be useful,       *
  11  *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
  12  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
  13  *   GNU General Public License for more details.                          *
  14  *                                                                         *
  15  *   You should have received a copy of the GNU General Public License     *
  16  *   along with this program; if not, write to the                         *
  17  *   Free Software Foundation, Inc.,                                       *
  18  *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
  19  ***************************************************************************/
  20
  21 #include "random.h"
  22
  23
  24 #if defined(Q_WS_X11) || defined(Q_WS_MAC)
  25         #include <QFile>
  26 #elif defined(Q_WS_WIN)
  27         #include <windows.h>
  28         #include <wincrypt.h>
  29         #include <QSysInfo>
  30 #endif
  31
  32 #include <QCryptographicHash>
  33 #include <QCursor>
  34 #include <QDataStream>
  35 #include <QTime>
  36
  37 void initStdRand();
  38 bool getNativeEntropy(quint8* buffer, int length);
  39
  40 void getEntropy(quint8* buffer, int length){
  41         if (!getNativeEntropy(buffer, length)) {
  42                 qWarning("Entropy collection failed, using fallback");
  43                 initStdRand();
  44                 for(int i=0;i<length;i++){
  45                         ((quint8*)buffer)[i] = (quint8) (qrand()%256);
  46                 }
  47         }
  48 }
  49
  50 quint32 randint(quint32 limit){
  51         quint32 rand;
  52         randomize(&rand, 4);
  53         return (rand % limit);
  54 }
  55
  56 quint32 randintRange(quint32 min, quint32 max){
  57         return min + randint(max-min+1);
  58 }
  59
  60 #if defined(Q_WS_X11) || defined(Q_WS_MAC)
  61
  62 extern bool getNativeEntropy(quint8* buffer, int length) {
  63         QFile dev_urandom("/dev/urandom");
  64         if (!dev_urandom.open(QIODevice::ReadOnly|QIODevice::Unbuffered))
  65                 return false;
  66         return (dev_urandom.read((char*)buffer,length) == length);
  67 }
  68
  69 #elif defined(Q_WS_WIN)
  70
  71 extern bool getNativeEntropy(quint8* buffer, int length) {
  72         HCRYPTPROV handle;
  73         if (!CryptAcquireContext(&handle, 0, 0,  PROV_RSA_FULL, CRYPT_VERIFYCONTEXT))
  74                 return false;
  75
  76         CryptGenRandom(handle, length, buffer);
  77         CryptReleaseContext(handle, 0);
  78
  79         return true;
  80 }
  81
  82 #endif
  83
  84 extern void initStdRand(){
  85         static bool initalized = false;
  86         if (initalized)
  87                 return;
  88
  89         QByteArray buffer;
  90         QDataStream stream(&buffer, QIODevice::WriteOnly);
  91
  92         stream << QCursor::pos();
  93         stream << QDateTime::currentDateTime().toTime_t();
  94         stream << QTime::currentTime().msec();
  95 #ifdef Q_WS_WIN
  96         stream << (quint32) GetCurrentProcessId();
  97 #else
  98         stream << getpid();
  99 #endif
 100         /* On a modern OS code, stack and heap base are randomized */
 101         quint64 code_value = (quint64)initStdRand;
 102         stream << code_value;
 103         stream << (quint64)&code_value;
 104
 105         QByteArray hash = QCryptographicHash::hash(buffer, QCryptographicHash::Sha1);
 106
 107         qsrand( *((uint*) hash.data()) );
 108         initalized = true;
 109 }