/* | |
* Platform-specific and custom entropy polling functions | |
* | |
* Copyright (C) 2006-2016, ARM Limited, All Rights Reserved | |
* SPDX-License-Identifier: Apache-2.0 | |
* | |
* Licensed under the Apache License, Version 2.0 (the "License"); you may | |
* not use this file except in compliance with the License. | |
* You may obtain a copy of the License at | |
* | |
* http://www.apache.org/licenses/LICENSE-2.0 | |
* | |
* Unless required by applicable law or agreed to in writing, software | |
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT | |
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | |
* See the License for the specific language governing permissions and | |
* limitations under the License. | |
* | |
* This file is part of mbed TLS (https://tls.mbed.org) | |
*/ | |
#if defined(__linux__) | |
/* Ensure that syscall() is available even when compiling with -std=c99 */ | |
#define _GNU_SOURCE | |
#endif | |
#if !defined(MBEDTLS_CONFIG_FILE) | |
#include "mbedtls/config.h" | |
#else | |
#include MBEDTLS_CONFIG_FILE | |
#endif | |
#include <string.h> | |
#if defined(MBEDTLS_ENTROPY_C) | |
#include "mbedtls/entropy.h" | |
#include "mbedtls/entropy_poll.h" | |
#if defined(MBEDTLS_TIMING_C) | |
#include "mbedtls/timing.h" | |
#endif | |
#if defined(MBEDTLS_HAVEGE_C) | |
#include "mbedtls/havege.h" | |
#endif | |
#if defined(MBEDTLS_ENTROPY_NV_SEED) | |
#include "mbedtls/platform.h" | |
#endif | |
#if !defined(MBEDTLS_NO_PLATFORM_ENTROPY) | |
#if !defined(unix) && !defined(__unix__) && !defined(__unix) && \ | |
!defined(__APPLE__) && !defined(_WIN32) && !defined(__QNXNTO__) && \ | |
!defined(__HAIKU__) | |
#error "Platform entropy sources only work on Unix and Windows, see MBEDTLS_NO_PLATFORM_ENTROPY in config.h" | |
#endif | |
#if defined(_WIN32) && !defined(EFIX64) && !defined(EFI32) | |
#if !defined(_WIN32_WINNT) | |
#define _WIN32_WINNT 0x0400 | |
#endif | |
#include <windows.h> | |
#include <wincrypt.h> | |
int mbedtls_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( MBEDTLS_ERR_ENTROPY_SOURCE_FAILED ); | |
} | |
if( CryptGenRandom( provider, (DWORD) len, output ) == FALSE ) | |
{ | |
CryptReleaseContext( provider, 0 ); | |
return( MBEDTLS_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 <unistd.h> | |
#include <sys/syscall.h> | |
#if defined(SYS_getrandom) | |
#define HAVE_GETRANDOM | |
#include <errno.h> | |
static int getrandom_wrapper( void *buf, size_t buflen, unsigned int flags ) | |
{ | |
/* MemSan cannot understand that the syscall writes to the buffer */ | |
#if defined(__has_feature) | |
#if __has_feature(memory_sanitizer) | |
memset( buf, 0, buflen ); | |
#endif | |
#endif | |
return( syscall( SYS_getrandom, buf, buflen, flags ) ); | |
} | |
#endif /* SYS_getrandom */ | |
#endif /* __linux__ */ | |
#include <stdio.h> | |
int mbedtls_platform_entropy_poll( void *data, | |
unsigned char *output, size_t len, size_t *olen ) | |
{ | |
FILE *file; | |
size_t read_len; | |
int ret; | |
((void) data); | |
#if defined(HAVE_GETRANDOM) | |
ret = getrandom_wrapper( output, len, 0 ); | |
if( ret >= 0 ) | |
{ | |
*olen = ret; | |
return( 0 ); | |
} | |
else if( errno != ENOSYS ) | |
return( MBEDTLS_ERR_ENTROPY_SOURCE_FAILED ); | |
/* Fall through if the system call isn't known. */ | |
#else | |
((void) ret); | |
#endif /* HAVE_GETRANDOM */ | |
*olen = 0; | |
file = fopen( "/dev/urandom", "rb" ); | |
if( file == NULL ) | |
return( MBEDTLS_ERR_ENTROPY_SOURCE_FAILED ); | |
read_len = fread( output, 1, len, file ); | |
if( read_len != len ) | |
{ | |
fclose( file ); | |
return( MBEDTLS_ERR_ENTROPY_SOURCE_FAILED ); | |
} | |
fclose( file ); | |
*olen = len; | |
return( 0 ); | |
} | |
#endif /* _WIN32 && !EFIX64 && !EFI32 */ | |
#endif /* !MBEDTLS_NO_PLATFORM_ENTROPY */ | |
#if defined(MBEDTLS_TEST_NULL_ENTROPY) | |
int mbedtls_null_entropy_poll( void *data, | |
unsigned char *output, size_t len, size_t *olen ) | |
{ | |
((void) data); | |
((void) output); | |
*olen = 0; | |
if( len < sizeof(unsigned char) ) | |
return( 0 ); | |
*olen = sizeof(unsigned char); | |
return( 0 ); | |
} | |
#endif | |
#if defined(MBEDTLS_TIMING_C) | |
int mbedtls_hardclock_poll( void *data, | |
unsigned char *output, size_t len, size_t *olen ) | |
{ | |
unsigned long timer = mbedtls_timing_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 /* MBEDTLS_TIMING_C */ | |
#if defined(MBEDTLS_HAVEGE_C) | |
int mbedtls_havege_poll( void *data, | |
unsigned char *output, size_t len, size_t *olen ) | |
{ | |
mbedtls_havege_state *hs = (mbedtls_havege_state *) data; | |
*olen = 0; | |
if( mbedtls_havege_random( hs, output, len ) != 0 ) | |
return( MBEDTLS_ERR_ENTROPY_SOURCE_FAILED ); | |
*olen = len; | |
return( 0 ); | |
} | |
#endif /* MBEDTLS_HAVEGE_C */ | |
#if defined(MBEDTLS_ENTROPY_NV_SEED) | |
int mbedtls_nv_seed_poll( void *data, | |
unsigned char *output, size_t len, size_t *olen ) | |
{ | |
unsigned char buf[MBEDTLS_ENTROPY_BLOCK_SIZE]; | |
size_t use_len = MBEDTLS_ENTROPY_BLOCK_SIZE; | |
((void) data); | |
memset( buf, 0, MBEDTLS_ENTROPY_BLOCK_SIZE ); | |
if( mbedtls_nv_seed_read( buf, MBEDTLS_ENTROPY_BLOCK_SIZE ) < 0 ) | |
return( MBEDTLS_ERR_ENTROPY_SOURCE_FAILED ); | |
if( len < use_len ) | |
use_len = len; | |
memcpy( output, buf, use_len ); | |
*olen = use_len; | |
return( 0 ); | |
} | |
#endif /* MBEDTLS_ENTROPY_NV_SEED */ | |
#endif /* MBEDTLS_ENTROPY_C */ |