mbed TLS library
Dependents: HTTPClient-SSL WS_SERVER
Diff: polarssl/entropy_poll.c
- Revision:
- 0:137634ff4186
diff -r 000000000000 -r 137634ff4186 polarssl/entropy_poll.c --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/polarssl/entropy_poll.c Thu Jun 11 03:27:03 2015 +0000 @@ -0,0 +1,211 @@ +/* + * Platform-specific and custom entropy polling functions + * + * Copyright (C) 2006-2014, ARM Limited, All Rights Reserved + * + * This file is part of mbed TLS (https://tls.mbed.org) + * + * 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. + */ + +#if !defined(POLARSSL_CONFIG_FILE) +#include "polarssl/config.h" +#else +#include POLARSSL_CONFIG_FILE +#endif + +#if defined(POLARSSL_ENTROPY_C) + +#include "polarssl/entropy.h" +#include "polarssl/entropy_poll.h" + +#if defined(POLARSSL_TIMING_C) +#include <string.h> +#include "polarssl/timing.h" +#endif +#if defined(POLARSSL_HAVEGE_C) +#include "polarssl/havege.h" +#endif + +#if !defined(POLARSSL_NO_PLATFORM_ENTROPY) +#if defined(_WIN32) && !defined(EFIX64) && !defined(EFI32) + +#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, (DWORD) len, output ) == FALSE ) + return( POLARSSL_ERR_ENTROPY_SOURCE_FAILED ); + + CryptReleaseContext( provider, 0 ); + *olen = len; + + return( 0 ); +} +#else /* _WIN32 && !EFIX64 && !EFI32 */ + +/* + * Test for Linux getrandom() support. + * Since there is no wrapper in the libc yet, use the generic syscall wrapper + * available in GNU libc and compatible libc's (eg uClibc). + */ +#if defined(__linux__) && defined(__GLIBC__) +#include <linux/version.h> +#include <unistd.h> +#include <sys/syscall.h> +#if defined(SYS_getrandom) +#define HAVE_GETRANDOM +static int getrandom_wrapper( void *buf, size_t buflen, unsigned int flags ) +{ + return( syscall( SYS_getrandom, buf, buflen, flags ) ); +} + +#include <sys/utsname.h> +/* Check if version is at least 3.17.0 */ +static int check_version_3_17_plus( void ) +{ + int minor; + struct utsname un; + const char *ver; + + /* Get version information */ + uname(&un); + ver = un.release; + + /* Check major version; assume a single digit */ + if( ver[0] < '3' || ver[0] > '9' || ver [1] != '.' ) + return( -1 ); + + if( ver[0] - '0' > 3 ) + return( 0 ); + + /* Ok, so now we know major == 3, check minor. + * Assume 1 or 2 digits. */ + if( ver[2] < '0' || ver[2] > '9' ) + return( -1 ); + + minor = ver[2] - '0'; + + if( ver[3] >= '0' && ver[3] <= '9' ) + minor = 10 * minor + ver[3] - '0'; + else if( ver [3] != '.' ) + return( -1 ); + + if( minor < 17 ) + return( -1 ); + + return( 0 ); +} +static int has_getrandom = -1; +#endif /* SYS_getrandom */ +#endif /* __linux__ */ + +#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); + +#if defined(HAVE_GETRANDOM) + if( has_getrandom == -1 ) + has_getrandom = ( check_version_3_17_plus() == 0 ); + + if( has_getrandom ) + { + int ret; + + if( ( ret = getrandom_wrapper( output, len, 0 ) ) < 0 ) + return( POLARSSL_ERR_ENTROPY_SOURCE_FAILED ); + + *olen = ret; + return( 0 ); + } +#endif /* HAVE_GETRANDOM */ + + *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 /* _WIN32 && !EFIX64 && !EFI32 */ +#endif /* !POLARSSL_NO_PLATFORM_ENTROPY */ + +#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 /* POLARSSL_TIMING_C */ + +#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 /* POLARSSL_HAVEGE_C */ + +#endif /* POLARSSL_ENTROPY_C */ +