277 lines
7.3 KiB
C
277 lines
7.3 KiB
C
/*
|
|
* Platform-specific and custom entropy polling functions
|
|
*
|
|
* Copyright The Mbed TLS Contributors
|
|
* SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
|
|
*
|
|
* This file is provided under the Apache License 2.0, or the
|
|
* GNU General Public License v2.0 or later.
|
|
*
|
|
* **********
|
|
* Apache License 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.
|
|
*
|
|
* **********
|
|
*
|
|
* **********
|
|
* GNU General Public License v2.0 or later:
|
|
*
|
|
* 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(__linux__) && !defined(_GNU_SOURCE)
|
|
/* 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 <bcrypt.h>
|
|
#if defined(_MSC_VER) && _MSC_VER <= 1600
|
|
/* Visual Studio 2010 and earlier issue a warning when both <stdint.h> and
|
|
* <intsafe.h> are included, as they redefine a number of <TYPE>_MAX constants.
|
|
* These constants are guaranteed to be the same, though, so we suppress the
|
|
* warning when including intsafe.h.
|
|
*/
|
|
#pragma warning( push )
|
|
#pragma warning( disable : 4005 )
|
|
#endif
|
|
#include <intsafe.h>
|
|
#if defined(_MSC_VER) && _MSC_VER <= 1600
|
|
#pragma warning( pop )
|
|
#endif
|
|
|
|
int mbedtls_platform_entropy_poll( void *data, unsigned char *output, size_t len,
|
|
size_t *olen )
|
|
{
|
|
ULONG len_as_ulong = 0;
|
|
((void) data);
|
|
*olen = 0;
|
|
|
|
/*
|
|
* BCryptGenRandom takes ULONG for size, which is smaller than size_t on
|
|
* 64-bit Windows platforms. Ensure len's value can be safely converted into
|
|
* a ULONG.
|
|
*/
|
|
if ( FAILED( SizeTToULong( len, &len_as_ulong ) ) )
|
|
{
|
|
return( MBEDTLS_ERR_ENTROPY_SOURCE_FAILED );
|
|
}
|
|
|
|
if ( !BCRYPT_SUCCESS( BCryptGenRandom( NULL, output, len_as_ulong, BCRYPT_USE_SYSTEM_PREFERRED_RNG ) ) )
|
|
{
|
|
return( MBEDTLS_ERR_ENTROPY_SOURCE_FAILED );
|
|
}
|
|
|
|
*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 */
|