diff options
Diffstat (limited to 'lib/mbedtls-2.27.0/library/entropy_poll.c')
-rw-r--r-- | lib/mbedtls-2.27.0/library/entropy_poll.c | 291 |
1 files changed, 291 insertions, 0 deletions
diff --git a/lib/mbedtls-2.27.0/library/entropy_poll.c b/lib/mbedtls-2.27.0/library/entropy_poll.c new file mode 100644 index 0000000..2c1e093 --- /dev/null +++ b/lib/mbedtls-2.27.0/library/entropy_poll.c @@ -0,0 +1,291 @@ +/* + * 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 <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__)) || 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 */ |