mbedtls/library/entropy_poll.c

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/*
* Platform-specific and custom entropy polling functions
*
* Copyright (C) 2006-2011, Brainspark B.V.
*
* This file is part of PolarSSL (http://www.polarssl.org)
* Lead Maintainer: Paul Bakker <polarssl_maintainer at polarssl.org>
*
* All rights reserved.
*
* This program 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, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include "polarssl/config.h"
#if defined(POLARSSL_ENTROPY_C)
#include "polarssl/entropy.h"
#include "polarssl/entropy_poll.h"
#if defined(POLARSSL_TIMING_C)
#include "polarssl/timing.h"
#endif
#if defined(POLARSSL_HAVEGE_C)
#include "polarssl/havege.h"
#endif
#if !defined(POLARSSL_NO_PLATFORM_ENTROPY)
#if defined(_WIN32)
#if !defined(_WIN32_WINNT)
#define _WIN32_WINNT 0x0400
#endif
#include <windows.h>
#include <wincrypt.h>
int platform_entropy_poll( void *data, unsigned char *output, size_t len,
size_t *olen )
{
HCRYPTPROV provider;
((void) data);
*olen = 0;
if( CryptAcquireContext( &provider, NULL, NULL,
PROV_RSA_FULL, CRYPT_VERIFYCONTEXT ) == FALSE )
{
return POLARSSL_ERR_ENTROPY_SOURCE_FAILED;
}
if( CryptGenRandom( provider, len, output ) == FALSE )
return POLARSSL_ERR_ENTROPY_SOURCE_FAILED;
CryptReleaseContext( provider, 0 );
*olen = len;
return( 0 );
}
#else
#include <stdio.h>
int platform_entropy_poll( void *data,
unsigned char *output, size_t len, size_t *olen )
{
FILE *file;
size_t ret;
((void) data);
*olen = 0;
file = fopen( "/dev/urandom", "rb" );
if( file == NULL )
return POLARSSL_ERR_ENTROPY_SOURCE_FAILED;
ret = fread( output, 1, len, file );
if( ret != len )
{
fclose( file );
return POLARSSL_ERR_ENTROPY_SOURCE_FAILED;
}
fclose( file );
*olen = len;
return( 0 );
}
#endif
#endif
#if defined(POLARSSL_TIMING_C)
int hardclock_poll( void *data,
unsigned char *output, size_t len, size_t *olen )
{
unsigned long timer = hardclock();
((void) data);
*olen = 0;
if( len < sizeof(unsigned long) )
return( 0 );
memcpy( output, &timer, sizeof(unsigned long) );
*olen = sizeof(unsigned long);
return( 0 );
}
#endif
#if defined(POLARSSL_HAVEGE_C)
int havege_poll( void *data,
unsigned char *output, size_t len, size_t *olen )
{
havege_state *hs = (havege_state *) data;
*olen = 0;
if( havege_random( hs, output, len ) != 0 )
return POLARSSL_ERR_ENTROPY_SOURCE_FAILED;
*olen = len;
return( 0 );
}
#endif
#endif /* POLARSSL_ENTROPY_C */