virtualx-engine/thirdparty/mbedtls/library/entropy_poll.c
Fabio Alessandrelli e375cbd094 Bump mbedTLS version to 2.28.0 (new LTS).
Keep applying the windows entropy patch (UWP support).
Remove no longer needed padlock patch.
Update thirdparty README to reflect changes, and new source inclusion
criteria.
2021-12-21 13:26:02 +01:00

306 lines
8.1 KiB
C

/*
* Platform-specific and custom entropy polling functions
*
* Copyright The Mbed TLS Contributors
* 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.
*/
#if defined(__linux__) && !defined(_GNU_SOURCE)
/* Ensure that syscall() is available even when compiling with -std=c99 */
#define _GNU_SOURCE
#endif
#include "common.h"
#include <string.h>
#if defined(MBEDTLS_ENTROPY_C)
#include "mbedtls/entropy.h"
#include "mbedtls/entropy_poll.h"
#include "mbedtls/error.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__) && !defined(__midipix__)
#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__)) || defined(__midipix__))
#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__ || __midipix__ */
#if defined(__FreeBSD__) || defined(__DragonFly__)
#include <sys/param.h>
#if (defined(__FreeBSD__) && __FreeBSD_version >= 1200000) || \
(defined(__DragonFly__) && __DragonFly_version >= 500700)
#include <errno.h>
#include <sys/random.h>
#define HAVE_GETRANDOM
static int getrandom_wrapper( void *buf, size_t buflen, unsigned int flags )
{
return getrandom( buf, buflen, flags );
}
#endif /* (__FreeBSD__ && __FreeBSD_version >= 1200000) ||
(__DragonFly__ && __DragonFly_version >= 500700) */
#endif /* __FreeBSD__ || __DragonFly__ */
/*
* Some BSD systems provide KERN_ARND.
* This is equivalent to reading from /dev/urandom, only it doesn't require an
* open file descriptor, and provides up to 256 bytes per call (basically the
* same as getentropy(), but with a longer history).
*
* Documentation: https://netbsd.gw.com/cgi-bin/man-cgi?sysctl+7
*/
#if (defined(__FreeBSD__) || defined(__NetBSD__)) && !defined(HAVE_GETRANDOM)
#include <sys/param.h>
#include <sys/sysctl.h>
#if defined(KERN_ARND)
#define HAVE_SYSCTL_ARND
static int sysctl_arnd_wrapper( unsigned char *buf, size_t buflen )
{
int name[2];
size_t len;
name[0] = CTL_KERN;
name[1] = KERN_ARND;
while( buflen > 0 )
{
len = buflen > 256 ? 256 : buflen;
if( sysctl(name, 2, buf, &len, NULL, 0) == -1 )
return( -1 );
buflen -= len;
buf += len;
}
return( 0 );
}
#endif /* KERN_ARND */
#endif /* __FreeBSD__ || __NetBSD__ */
#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 = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
((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 */
#if defined(HAVE_SYSCTL_ARND)
((void) file);
((void) read_len);
if( sysctl_arnd_wrapper( output, len ) == -1 )
return( MBEDTLS_ERR_ENTROPY_SOURCE_FAILED );
*olen = len;
return( 0 );
#else
*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 /* HAVE_SYSCTL_ARND */
}
#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 );
output[0] = 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 */