Edison Ai | 7b07920 | 2018-02-28 15:01:47 +0800 | [diff] [blame] | 1 | // SPDX-License-Identifier: Apache-2.0 |
Jens Wiklander | 817466c | 2018-05-22 13:49:31 +0200 | [diff] [blame] | 2 | /* |
| 3 | * Platform-specific and custom entropy polling functions |
| 4 | * |
| 5 | * Copyright (C) 2006-2016, ARM Limited, All Rights Reserved |
Jens Wiklander | 817466c | 2018-05-22 13:49:31 +0200 | [diff] [blame] | 6 | * |
| 7 | * Licensed under the Apache License, Version 2.0 (the "License"); you may |
| 8 | * not use this file except in compliance with the License. |
| 9 | * You may obtain a copy of the License at |
| 10 | * |
| 11 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 12 | * |
| 13 | * Unless required by applicable law or agreed to in writing, software |
| 14 | * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT |
| 15 | * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 16 | * See the License for the specific language governing permissions and |
| 17 | * limitations under the License. |
| 18 | * |
| 19 | * This file is part of mbed TLS (https://tls.mbed.org) |
| 20 | */ |
| 21 | |
Jens Wiklander | 50a57cf | 2019-03-13 10:41:54 +0100 | [diff] [blame] | 22 | #if defined(__linux__) |
| 23 | /* Ensure that syscall() is available even when compiling with -std=c99 */ |
| 24 | #define _GNU_SOURCE |
| 25 | #endif |
| 26 | |
Jens Wiklander | 817466c | 2018-05-22 13:49:31 +0200 | [diff] [blame] | 27 | #if !defined(MBEDTLS_CONFIG_FILE) |
| 28 | #include "mbedtls/config.h" |
| 29 | #else |
| 30 | #include MBEDTLS_CONFIG_FILE |
| 31 | #endif |
| 32 | |
Jens Wiklander | 50a57cf | 2019-03-13 10:41:54 +0100 | [diff] [blame] | 33 | #include <string.h> |
| 34 | |
Jens Wiklander | 817466c | 2018-05-22 13:49:31 +0200 | [diff] [blame] | 35 | #if defined(MBEDTLS_ENTROPY_C) |
| 36 | |
| 37 | #include "mbedtls/entropy.h" |
| 38 | #include "mbedtls/entropy_poll.h" |
| 39 | |
| 40 | #if defined(MBEDTLS_TIMING_C) |
Jens Wiklander | 817466c | 2018-05-22 13:49:31 +0200 | [diff] [blame] | 41 | #include "mbedtls/timing.h" |
| 42 | #endif |
| 43 | #if defined(MBEDTLS_HAVEGE_C) |
| 44 | #include "mbedtls/havege.h" |
| 45 | #endif |
| 46 | #if defined(MBEDTLS_ENTROPY_NV_SEED) |
| 47 | #include "mbedtls/platform.h" |
| 48 | #endif |
| 49 | |
| 50 | #if !defined(MBEDTLS_NO_PLATFORM_ENTROPY) |
| 51 | |
| 52 | #if !defined(unix) && !defined(__unix__) && !defined(__unix) && \ |
Jens Wiklander | 50a57cf | 2019-03-13 10:41:54 +0100 | [diff] [blame] | 53 | !defined(__APPLE__) && !defined(_WIN32) && !defined(__QNXNTO__) && \ |
| 54 | !defined(__HAIKU__) |
Jens Wiklander | 817466c | 2018-05-22 13:49:31 +0200 | [diff] [blame] | 55 | #error "Platform entropy sources only work on Unix and Windows, see MBEDTLS_NO_PLATFORM_ENTROPY in config.h" |
| 56 | #endif |
| 57 | |
| 58 | #if defined(_WIN32) && !defined(EFIX64) && !defined(EFI32) |
| 59 | |
| 60 | #if !defined(_WIN32_WINNT) |
| 61 | #define _WIN32_WINNT 0x0400 |
| 62 | #endif |
| 63 | #include <windows.h> |
| 64 | #include <wincrypt.h> |
| 65 | |
| 66 | int mbedtls_platform_entropy_poll( void *data, unsigned char *output, size_t len, |
| 67 | size_t *olen ) |
| 68 | { |
| 69 | HCRYPTPROV provider; |
| 70 | ((void) data); |
| 71 | *olen = 0; |
| 72 | |
| 73 | if( CryptAcquireContext( &provider, NULL, NULL, |
| 74 | PROV_RSA_FULL, CRYPT_VERIFYCONTEXT ) == FALSE ) |
| 75 | { |
| 76 | return( MBEDTLS_ERR_ENTROPY_SOURCE_FAILED ); |
| 77 | } |
| 78 | |
| 79 | if( CryptGenRandom( provider, (DWORD) len, output ) == FALSE ) |
| 80 | { |
| 81 | CryptReleaseContext( provider, 0 ); |
| 82 | return( MBEDTLS_ERR_ENTROPY_SOURCE_FAILED ); |
| 83 | } |
| 84 | |
| 85 | CryptReleaseContext( provider, 0 ); |
| 86 | *olen = len; |
| 87 | |
| 88 | return( 0 ); |
| 89 | } |
| 90 | #else /* _WIN32 && !EFIX64 && !EFI32 */ |
| 91 | |
| 92 | /* |
| 93 | * Test for Linux getrandom() support. |
| 94 | * Since there is no wrapper in the libc yet, use the generic syscall wrapper |
| 95 | * available in GNU libc and compatible libc's (eg uClibc). |
| 96 | */ |
| 97 | #if defined(__linux__) && defined(__GLIBC__) |
| 98 | #include <unistd.h> |
| 99 | #include <sys/syscall.h> |
| 100 | #if defined(SYS_getrandom) |
| 101 | #define HAVE_GETRANDOM |
Jens Wiklander | 50a57cf | 2019-03-13 10:41:54 +0100 | [diff] [blame] | 102 | #include <errno.h> |
Jens Wiklander | 817466c | 2018-05-22 13:49:31 +0200 | [diff] [blame] | 103 | |
| 104 | static int getrandom_wrapper( void *buf, size_t buflen, unsigned int flags ) |
| 105 | { |
| 106 | /* MemSan cannot understand that the syscall writes to the buffer */ |
| 107 | #if defined(__has_feature) |
| 108 | #if __has_feature(memory_sanitizer) |
| 109 | memset( buf, 0, buflen ); |
| 110 | #endif |
| 111 | #endif |
Jens Wiklander | 817466c | 2018-05-22 13:49:31 +0200 | [diff] [blame] | 112 | return( syscall( SYS_getrandom, buf, buflen, flags ) ); |
| 113 | } |
Jens Wiklander | 817466c | 2018-05-22 13:49:31 +0200 | [diff] [blame] | 114 | #endif /* SYS_getrandom */ |
| 115 | #endif /* __linux__ */ |
| 116 | |
| 117 | #include <stdio.h> |
| 118 | |
| 119 | int mbedtls_platform_entropy_poll( void *data, |
| 120 | unsigned char *output, size_t len, size_t *olen ) |
| 121 | { |
| 122 | FILE *file; |
| 123 | size_t read_len; |
Jens Wiklander | 50a57cf | 2019-03-13 10:41:54 +0100 | [diff] [blame] | 124 | int ret; |
Jens Wiklander | 817466c | 2018-05-22 13:49:31 +0200 | [diff] [blame] | 125 | ((void) data); |
| 126 | |
| 127 | #if defined(HAVE_GETRANDOM) |
Jens Wiklander | 50a57cf | 2019-03-13 10:41:54 +0100 | [diff] [blame] | 128 | ret = getrandom_wrapper( output, len, 0 ); |
| 129 | if( ret >= 0 ) |
Jens Wiklander | 817466c | 2018-05-22 13:49:31 +0200 | [diff] [blame] | 130 | { |
Jens Wiklander | 817466c | 2018-05-22 13:49:31 +0200 | [diff] [blame] | 131 | *olen = ret; |
| 132 | return( 0 ); |
| 133 | } |
Jens Wiklander | 50a57cf | 2019-03-13 10:41:54 +0100 | [diff] [blame] | 134 | else if( errno != ENOSYS ) |
| 135 | return( MBEDTLS_ERR_ENTROPY_SOURCE_FAILED ); |
| 136 | /* Fall through if the system call isn't known. */ |
| 137 | #else |
| 138 | ((void) ret); |
Jens Wiklander | 817466c | 2018-05-22 13:49:31 +0200 | [diff] [blame] | 139 | #endif /* HAVE_GETRANDOM */ |
| 140 | |
| 141 | *olen = 0; |
| 142 | |
| 143 | file = fopen( "/dev/urandom", "rb" ); |
| 144 | if( file == NULL ) |
| 145 | return( MBEDTLS_ERR_ENTROPY_SOURCE_FAILED ); |
| 146 | |
| 147 | read_len = fread( output, 1, len, file ); |
| 148 | if( read_len != len ) |
| 149 | { |
| 150 | fclose( file ); |
| 151 | return( MBEDTLS_ERR_ENTROPY_SOURCE_FAILED ); |
| 152 | } |
| 153 | |
| 154 | fclose( file ); |
| 155 | *olen = len; |
| 156 | |
| 157 | return( 0 ); |
| 158 | } |
| 159 | #endif /* _WIN32 && !EFIX64 && !EFI32 */ |
| 160 | #endif /* !MBEDTLS_NO_PLATFORM_ENTROPY */ |
| 161 | |
| 162 | #if defined(MBEDTLS_TEST_NULL_ENTROPY) |
| 163 | int mbedtls_null_entropy_poll( void *data, |
| 164 | unsigned char *output, size_t len, size_t *olen ) |
| 165 | { |
| 166 | ((void) data); |
| 167 | ((void) output); |
| 168 | *olen = 0; |
| 169 | |
| 170 | if( len < sizeof(unsigned char) ) |
| 171 | return( 0 ); |
| 172 | |
| 173 | *olen = sizeof(unsigned char); |
| 174 | |
| 175 | return( 0 ); |
| 176 | } |
| 177 | #endif |
| 178 | |
| 179 | #if defined(MBEDTLS_TIMING_C) |
| 180 | int mbedtls_hardclock_poll( void *data, |
| 181 | unsigned char *output, size_t len, size_t *olen ) |
| 182 | { |
| 183 | unsigned long timer = mbedtls_timing_hardclock(); |
| 184 | ((void) data); |
| 185 | *olen = 0; |
| 186 | |
| 187 | if( len < sizeof(unsigned long) ) |
| 188 | return( 0 ); |
| 189 | |
| 190 | memcpy( output, &timer, sizeof(unsigned long) ); |
| 191 | *olen = sizeof(unsigned long); |
| 192 | |
| 193 | return( 0 ); |
| 194 | } |
| 195 | #endif /* MBEDTLS_TIMING_C */ |
| 196 | |
| 197 | #if defined(MBEDTLS_HAVEGE_C) |
| 198 | int mbedtls_havege_poll( void *data, |
| 199 | unsigned char *output, size_t len, size_t *olen ) |
| 200 | { |
| 201 | mbedtls_havege_state *hs = (mbedtls_havege_state *) data; |
| 202 | *olen = 0; |
| 203 | |
| 204 | if( mbedtls_havege_random( hs, output, len ) != 0 ) |
| 205 | return( MBEDTLS_ERR_ENTROPY_SOURCE_FAILED ); |
| 206 | |
| 207 | *olen = len; |
| 208 | |
| 209 | return( 0 ); |
| 210 | } |
| 211 | #endif /* MBEDTLS_HAVEGE_C */ |
| 212 | |
| 213 | #if defined(MBEDTLS_ENTROPY_NV_SEED) |
| 214 | int mbedtls_nv_seed_poll( void *data, |
| 215 | unsigned char *output, size_t len, size_t *olen ) |
| 216 | { |
| 217 | unsigned char buf[MBEDTLS_ENTROPY_BLOCK_SIZE]; |
| 218 | size_t use_len = MBEDTLS_ENTROPY_BLOCK_SIZE; |
| 219 | ((void) data); |
| 220 | |
| 221 | memset( buf, 0, MBEDTLS_ENTROPY_BLOCK_SIZE ); |
| 222 | |
| 223 | if( mbedtls_nv_seed_read( buf, MBEDTLS_ENTROPY_BLOCK_SIZE ) < 0 ) |
| 224 | return( MBEDTLS_ERR_ENTROPY_SOURCE_FAILED ); |
| 225 | |
| 226 | if( len < use_len ) |
| 227 | use_len = len; |
| 228 | |
| 229 | memcpy( output, buf, use_len ); |
| 230 | *olen = use_len; |
| 231 | |
| 232 | return( 0 ); |
| 233 | } |
| 234 | #endif /* MBEDTLS_ENTROPY_NV_SEED */ |
| 235 | |
| 236 | #endif /* MBEDTLS_ENTROPY_C */ |