Line data    Source code

       1             : 
       2             : /* Copyright (c) 2010-2012, Stefan Eilemann <eile@equalizergraphics.com>
       3             :  *                    2012, Daniel Nachbaur <danielnachbaur@gmail.com>
       4             :  *
       5             :  * This library is free software; you can redistribute it and/or modify it under
       6             :  * the terms of the GNU Lesser General Public License version 2.1 as published
       7             :  * by the Free Software Foundation.
       8             :  *  
       9             :  * This library is distributed in the hope that it will be useful, but WITHOUT
      10             :  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
      11             :  * FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more
      12             :  * details.
      13             :  * 
      14             :  * You should have received a copy of the GNU Lesser General Public License
      15             :  * along with this library; if not, write to the Free Software Foundation, Inc.,
      16             :  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
      17             :  */
      18             : 
      19             : #include "rng.h"
      20             : 
      21             : #pragma warning (push)
      22             : #pragma warning (disable: 4985) // inconsistent decl of ceil
      23             : 
      24             : #ifdef _WIN32
      25             : #  ifndef NOMINMAX
      26             : #    define NOMINMAX
      27             : #  endif
      28             : #  include <wtypes.h>
      29             : #  include <wincrypt.h>
      30             : #  pragma comment(lib, "advapi32.lib")
      31             : #else
      32             : #  include <unistd.h>
      33             : #endif
      34             : 
      35             : #include <cstdlib>
      36             : #include <fcntl.h>
      37             : #include <limits>
      38             : #include <stdio.h>
      39             : #pragma warning (pop)
      40             : 
      41             : 
      42             : namespace lunchbox
      43             : {
      44             : namespace
      45             : {
      46             : #ifdef __linux__
      47             : static int _fd = -1;
      48             : #elif defined (_WIN32)
      49             : static HCRYPTPROV _provider = 0;
      50             : #endif
      51             : }
      52             : 
      53      100425 : RNG::RNG()
      54      100425 :         : _impl( 0 )
      55             : {
      56      100161 :     _init();
      57      100187 : }
      58             : 
      59      101035 : RNG::~RNG()
      60      101035 : {}
      61             : 
      62      100175 : bool RNG::_init()
      63             : {
      64             : #ifdef __APPLE__
      65             :     srandomdev();
      66             : #elif defined (__linux__)
      67             :     static int fd = -1; // prevent static initializer fiasco
      68      100175 :     if( fd >= 0 )
      69      100166 :         return true;
      70             : 
      71           9 :     fd = ::open( "/dev/urandom", O_RDONLY );
      72           9 :     if( fd >= 0 )
      73           9 :         ::atexit( RNG::_exit );
      74             :     else
      75             :     {
      76           0 :         LBERROR << "Failed to open /dev/urandom: " << sysError << std::endl;
      77           0 :         return false;
      78             :     }
      79           9 :     _fd = fd;
      80             : 
      81             : #elif defined (_WIN32)
      82             : 
      83             :     static HCRYPTPROV provider = 0; // prevent static initializer fiasco
      84             :     if( provider )
      85             :         return true;
      86             : 
      87             :     if( CryptAcquireContext( &provider, 0, 0, PROV_RSA_FULL,
      88             :                               CRYPT_VERIFYCONTEXT ) || !provider )
      89             :     {
      90             :         ::atexit( RNG::_exit );
      91             :     }
      92             :     else
      93             :     {
      94             :         LBERROR << "Failed to acquire crypto context: " << sysError <<std::endl;
      95             :         return false;
      96             :     }
      97             : 
      98             :     _provider = provider;
      99             : #endif
     100           9 :     return true;
     101             : }
     102             : 
     103           9 : void RNG::_exit()
     104             : {
     105             : #ifdef __linux__
     106           9 :     if( _fd >= 0 )
     107             :     {
     108           9 :         ::close( _fd );
     109           9 :         _fd = -1;
     110             :     }
     111             : #elif defined (_WIN32)
     112             :     if( _provider && !CryptReleaseContext( _provider, 0 ))
     113             :         LBERROR << "Failed to release crypto context: " << sysError
     114             :                 << std::endl;
     115             :     _provider = 0;
     116             : #endif
     117           9 : }
     118             : 
     119           0 : void RNG::reseed()
     120             : {
     121             : #ifdef __APPLE__
     122             :     srandomdev();
     123             : #endif
     124           0 : }
     125             : 
     126    11197300 : bool RNG::_get( void* data, const size_t size )
     127             : {
     128             : #ifdef __linux__
     129    11197300 :     LBASSERTINFO( _fd >= 0, "init() not called?" );
     130    11197500 :     int read = ::read( _fd, data, size );
     131    11198771 :     LBASSERTINFO( read == ssize_t( size ),
     132             :                   read << " != " << size << ": " << sysError );
     133    11200423 :     if( read != ssize_t( size ))
     134             :     {
     135           0 :         LBERROR << "random number generator not working" << std::endl;
     136           0 :         return false;
     137             :     }
     138             : 
     139             : #elif defined (_WIN32)
     140             :     LBASSERTINFO( _provider, "init() not called?" );
     141             :     if( !CryptGenRandom( _provider, (DWORD)size, (BYTE*)data ))
     142             :     {
     143             :         LBERROR << "random number generator not working" << std::endl;
     144             :         return false;
     145             :     }
     146             : #else // __APPLE__
     147             :     uint8_t* ptr = reinterpret_cast< uint8_t* >( data );
     148             :     for( size_t i=0; i < size; ++i )
     149             :         ptr[i] = ( random() & 0xff );
     150             : #endif
     151    11200423 :     return true;
     152             : }
     153             : 
     154          90 : }