Kev Mann / mbed-dev-OS5_10_4

RTC auf true

features/mbedtls/src/entropy_poll.c@0:38ceb79fef03, 2018-11-28 (annotated)

Committer:
kevman
Date:
Wed Nov 28 15:10:15 2018 +0000
Revision:
0:38ceb79fef03
RTC modified

Who changed what in which revision?

UserRevisionLine numberNew contents of line
kevman 0:38ceb79fef03 1 /*
kevman 0:38ceb79fef03 2 * Platform-specific and custom entropy polling functions
kevman 0:38ceb79fef03 3 *
kevman 0:38ceb79fef03 4 * Copyright (C) 2006-2016, ARM Limited, All Rights Reserved
kevman 0:38ceb79fef03 5 * SPDX-License-Identifier: Apache-2.0
kevman 0:38ceb79fef03 6 *
kevman 0:38ceb79fef03 7 * Licensed under the Apache License, Version 2.0 (the "License"); you may
kevman 0:38ceb79fef03 8 * not use this file except in compliance with the License.
kevman 0:38ceb79fef03 9 * You may obtain a copy of the License at
kevman 0:38ceb79fef03 10 *
kevman 0:38ceb79fef03 11 * http://www.apache.org/licenses/LICENSE-2.0
kevman 0:38ceb79fef03 12 *
kevman 0:38ceb79fef03 13 * Unless required by applicable law or agreed to in writing, software
kevman 0:38ceb79fef03 14 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
kevman 0:38ceb79fef03 15 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
kevman 0:38ceb79fef03 16 * See the License for the specific language governing permissions and
kevman 0:38ceb79fef03 17 * limitations under the License.
kevman 0:38ceb79fef03 18 *
kevman 0:38ceb79fef03 19 * This file is part of mbed TLS (https://tls.mbed.org)
kevman 0:38ceb79fef03 20 */
kevman 0:38ceb79fef03 21
kevman 0:38ceb79fef03 22 #if defined(__linux__)
kevman 0:38ceb79fef03 23 /* Ensure that syscall() is available even when compiling with -std=c99 */
kevman 0:38ceb79fef03 24 #define _GNU_SOURCE
kevman 0:38ceb79fef03 25 #endif
kevman 0:38ceb79fef03 26
kevman 0:38ceb79fef03 27 #if !defined(MBEDTLS_CONFIG_FILE)
kevman 0:38ceb79fef03 28 #include "mbedtls/config.h"
kevman 0:38ceb79fef03 29 #else
kevman 0:38ceb79fef03 30 #include MBEDTLS_CONFIG_FILE
kevman 0:38ceb79fef03 31 #endif
kevman 0:38ceb79fef03 32
kevman 0:38ceb79fef03 33 #include <string.h>
kevman 0:38ceb79fef03 34
kevman 0:38ceb79fef03 35 #if defined(MBEDTLS_ENTROPY_C)
kevman 0:38ceb79fef03 36
kevman 0:38ceb79fef03 37 #include "mbedtls/entropy.h"
kevman 0:38ceb79fef03 38 #include "mbedtls/entropy_poll.h"
kevman 0:38ceb79fef03 39
kevman 0:38ceb79fef03 40 #if defined(MBEDTLS_TIMING_C)
kevman 0:38ceb79fef03 41 #include "mbedtls/timing.h"
kevman 0:38ceb79fef03 42 #endif
kevman 0:38ceb79fef03 43 #if defined(MBEDTLS_HAVEGE_C)
kevman 0:38ceb79fef03 44 #include "mbedtls/havege.h"
kevman 0:38ceb79fef03 45 #endif
kevman 0:38ceb79fef03 46 #if defined(MBEDTLS_ENTROPY_NV_SEED)
kevman 0:38ceb79fef03 47 #include "mbedtls/platform.h"
kevman 0:38ceb79fef03 48 #endif
kevman 0:38ceb79fef03 49
kevman 0:38ceb79fef03 50 #if !defined(MBEDTLS_NO_PLATFORM_ENTROPY)
kevman 0:38ceb79fef03 51
kevman 0:38ceb79fef03 52 #if !defined(unix) && !defined(__unix__) && !defined(__unix) && \
kevman 0:38ceb79fef03 53 !defined(__APPLE__) && !defined(_WIN32) && !defined(__QNXNTO__) && \
kevman 0:38ceb79fef03 54 !defined(__HAIKU__)
kevman 0:38ceb79fef03 55 #error "Platform entropy sources only work on Unix and Windows, see MBEDTLS_NO_PLATFORM_ENTROPY in config.h"
kevman 0:38ceb79fef03 56 #endif
kevman 0:38ceb79fef03 57
kevman 0:38ceb79fef03 58 #if defined(_WIN32) && !defined(EFIX64) && !defined(EFI32)
kevman 0:38ceb79fef03 59
kevman 0:38ceb79fef03 60 #if !defined(_WIN32_WINNT)
kevman 0:38ceb79fef03 61 #define _WIN32_WINNT 0x0400
kevman 0:38ceb79fef03 62 #endif
kevman 0:38ceb79fef03 63 #include <windows.h>
kevman 0:38ceb79fef03 64 #include <wincrypt.h>
kevman 0:38ceb79fef03 65
kevman 0:38ceb79fef03 66 int mbedtls_platform_entropy_poll( void *data, unsigned char *output, size_t len,
kevman 0:38ceb79fef03 67 size_t *olen )
kevman 0:38ceb79fef03 68 {
kevman 0:38ceb79fef03 69 HCRYPTPROV provider;
kevman 0:38ceb79fef03 70 ((void) data);
kevman 0:38ceb79fef03 71 *olen = 0;
kevman 0:38ceb79fef03 72
kevman 0:38ceb79fef03 73 if( CryptAcquireContext( &provider, NULL, NULL,
kevman 0:38ceb79fef03 74 PROV_RSA_FULL, CRYPT_VERIFYCONTEXT ) == FALSE )
kevman 0:38ceb79fef03 75 {
kevman 0:38ceb79fef03 76 return( MBEDTLS_ERR_ENTROPY_SOURCE_FAILED );
kevman 0:38ceb79fef03 77 }
kevman 0:38ceb79fef03 78
kevman 0:38ceb79fef03 79 if( CryptGenRandom( provider, (DWORD) len, output ) == FALSE )
kevman 0:38ceb79fef03 80 {
kevman 0:38ceb79fef03 81 CryptReleaseContext( provider, 0 );
kevman 0:38ceb79fef03 82 return( MBEDTLS_ERR_ENTROPY_SOURCE_FAILED );
kevman 0:38ceb79fef03 83 }
kevman 0:38ceb79fef03 84
kevman 0:38ceb79fef03 85 CryptReleaseContext( provider, 0 );
kevman 0:38ceb79fef03 86 *olen = len;
kevman 0:38ceb79fef03 87
kevman 0:38ceb79fef03 88 return( 0 );
kevman 0:38ceb79fef03 89 }
kevman 0:38ceb79fef03 90 #else /* _WIN32 && !EFIX64 && !EFI32 */
kevman 0:38ceb79fef03 91
kevman 0:38ceb79fef03 92 /*
kevman 0:38ceb79fef03 93 * Test for Linux getrandom() support.
kevman 0:38ceb79fef03 94 * Since there is no wrapper in the libc yet, use the generic syscall wrapper
kevman 0:38ceb79fef03 95 * available in GNU libc and compatible libc's (eg uClibc).
kevman 0:38ceb79fef03 96 */
kevman 0:38ceb79fef03 97 #if defined(__linux__) && defined(__GLIBC__)
kevman 0:38ceb79fef03 98 #include <unistd.h>
kevman 0:38ceb79fef03 99 #include <sys/syscall.h>
kevman 0:38ceb79fef03 100 #if defined(SYS_getrandom)
kevman 0:38ceb79fef03 101 #define HAVE_GETRANDOM
kevman 0:38ceb79fef03 102
kevman 0:38ceb79fef03 103 static int getrandom_wrapper( void *buf, size_t buflen, unsigned int flags )
kevman 0:38ceb79fef03 104 {
kevman 0:38ceb79fef03 105 /* MemSan cannot understand that the syscall writes to the buffer */
kevman 0:38ceb79fef03 106 #if defined(__has_feature)
kevman 0:38ceb79fef03 107 #if __has_feature(memory_sanitizer)
kevman 0:38ceb79fef03 108 memset( buf, 0, buflen );
kevman 0:38ceb79fef03 109 #endif
kevman 0:38ceb79fef03 110 #endif
kevman 0:38ceb79fef03 111
kevman 0:38ceb79fef03 112 return( syscall( SYS_getrandom, buf, buflen, flags ) );
kevman 0:38ceb79fef03 113 }
kevman 0:38ceb79fef03 114
kevman 0:38ceb79fef03 115 #include <sys/utsname.h>
kevman 0:38ceb79fef03 116 /* Check if version is at least 3.17.0 */
kevman 0:38ceb79fef03 117 static int check_version_3_17_plus( void )
kevman 0:38ceb79fef03 118 {
kevman 0:38ceb79fef03 119 int minor;
kevman 0:38ceb79fef03 120 struct utsname un;
kevman 0:38ceb79fef03 121 const char *ver;
kevman 0:38ceb79fef03 122
kevman 0:38ceb79fef03 123 /* Get version information */
kevman 0:38ceb79fef03 124 uname(&un);
kevman 0:38ceb79fef03 125 ver = un.release;
kevman 0:38ceb79fef03 126
kevman 0:38ceb79fef03 127 /* Check major version; assume a single digit */
kevman 0:38ceb79fef03 128 if( ver[0] < '3' || ver[0] > '9' || ver [1] != '.' )
kevman 0:38ceb79fef03 129 return( -1 );
kevman 0:38ceb79fef03 130
kevman 0:38ceb79fef03 131 if( ver[0] - '0' > 3 )
kevman 0:38ceb79fef03 132 return( 0 );
kevman 0:38ceb79fef03 133
kevman 0:38ceb79fef03 134 /* Ok, so now we know major == 3, check minor.
kevman 0:38ceb79fef03 135 * Assume 1 or 2 digits. */
kevman 0:38ceb79fef03 136 if( ver[2] < '0' || ver[2] > '9' )
kevman 0:38ceb79fef03 137 return( -1 );
kevman 0:38ceb79fef03 138
kevman 0:38ceb79fef03 139 minor = ver[2] - '0';
kevman 0:38ceb79fef03 140
kevman 0:38ceb79fef03 141 if( ver[3] >= '0' && ver[3] <= '9' )
kevman 0:38ceb79fef03 142 minor = 10 * minor + ver[3] - '0';
kevman 0:38ceb79fef03 143 else if( ver [3] != '.' )
kevman 0:38ceb79fef03 144 return( -1 );
kevman 0:38ceb79fef03 145
kevman 0:38ceb79fef03 146 if( minor < 17 )
kevman 0:38ceb79fef03 147 return( -1 );
kevman 0:38ceb79fef03 148
kevman 0:38ceb79fef03 149 return( 0 );
kevman 0:38ceb79fef03 150 }
kevman 0:38ceb79fef03 151 static int has_getrandom = -1;
kevman 0:38ceb79fef03 152 #endif /* SYS_getrandom */
kevman 0:38ceb79fef03 153 #endif /* __linux__ */
kevman 0:38ceb79fef03 154
kevman 0:38ceb79fef03 155 #include <stdio.h>
kevman 0:38ceb79fef03 156
kevman 0:38ceb79fef03 157 int mbedtls_platform_entropy_poll( void *data,
kevman 0:38ceb79fef03 158 unsigned char *output, size_t len, size_t *olen )
kevman 0:38ceb79fef03 159 {
kevman 0:38ceb79fef03 160 FILE *file;
kevman 0:38ceb79fef03 161 size_t read_len;
kevman 0:38ceb79fef03 162 ((void) data);
kevman 0:38ceb79fef03 163
kevman 0:38ceb79fef03 164 #if defined(HAVE_GETRANDOM)
kevman 0:38ceb79fef03 165 if( has_getrandom == -1 )
kevman 0:38ceb79fef03 166 has_getrandom = ( check_version_3_17_plus() == 0 );
kevman 0:38ceb79fef03 167
kevman 0:38ceb79fef03 168 if( has_getrandom )
kevman 0:38ceb79fef03 169 {
kevman 0:38ceb79fef03 170 int ret;
kevman 0:38ceb79fef03 171
kevman 0:38ceb79fef03 172 if( ( ret = getrandom_wrapper( output, len, 0 ) ) < 0 )
kevman 0:38ceb79fef03 173 return( MBEDTLS_ERR_ENTROPY_SOURCE_FAILED );
kevman 0:38ceb79fef03 174
kevman 0:38ceb79fef03 175 *olen = ret;
kevman 0:38ceb79fef03 176 return( 0 );
kevman 0:38ceb79fef03 177 }
kevman 0:38ceb79fef03 178 #endif /* HAVE_GETRANDOM */
kevman 0:38ceb79fef03 179
kevman 0:38ceb79fef03 180 *olen = 0;
kevman 0:38ceb79fef03 181
kevman 0:38ceb79fef03 182 file = fopen( "/dev/urandom", "rb" );
kevman 0:38ceb79fef03 183 if( file == NULL )
kevman 0:38ceb79fef03 184 return( MBEDTLS_ERR_ENTROPY_SOURCE_FAILED );
kevman 0:38ceb79fef03 185
kevman 0:38ceb79fef03 186 read_len = fread( output, 1, len, file );
kevman 0:38ceb79fef03 187 if( read_len != len )
kevman 0:38ceb79fef03 188 {
kevman 0:38ceb79fef03 189 fclose( file );
kevman 0:38ceb79fef03 190 return( MBEDTLS_ERR_ENTROPY_SOURCE_FAILED );
kevman 0:38ceb79fef03 191 }
kevman 0:38ceb79fef03 192
kevman 0:38ceb79fef03 193 fclose( file );
kevman 0:38ceb79fef03 194 *olen = len;
kevman 0:38ceb79fef03 195
kevman 0:38ceb79fef03 196 return( 0 );
kevman 0:38ceb79fef03 197 }
kevman 0:38ceb79fef03 198 #endif /* _WIN32 && !EFIX64 && !EFI32 */
kevman 0:38ceb79fef03 199 #endif /* !MBEDTLS_NO_PLATFORM_ENTROPY */
kevman 0:38ceb79fef03 200
kevman 0:38ceb79fef03 201 #if defined(MBEDTLS_TEST_NULL_ENTROPY)
kevman 0:38ceb79fef03 202 int mbedtls_null_entropy_poll( void *data,
kevman 0:38ceb79fef03 203 unsigned char *output, size_t len, size_t *olen )
kevman 0:38ceb79fef03 204 {
kevman 0:38ceb79fef03 205 ((void) data);
kevman 0:38ceb79fef03 206 ((void) output);
kevman 0:38ceb79fef03 207 *olen = 0;
kevman 0:38ceb79fef03 208
kevman 0:38ceb79fef03 209 if( len < sizeof(unsigned char) )
kevman 0:38ceb79fef03 210 return( 0 );
kevman 0:38ceb79fef03 211
kevman 0:38ceb79fef03 212 *olen = sizeof(unsigned char);
kevman 0:38ceb79fef03 213
kevman 0:38ceb79fef03 214 return( 0 );
kevman 0:38ceb79fef03 215 }
kevman 0:38ceb79fef03 216 #endif
kevman 0:38ceb79fef03 217
kevman 0:38ceb79fef03 218 #if defined(MBEDTLS_TIMING_C)
kevman 0:38ceb79fef03 219 int mbedtls_hardclock_poll( void *data,
kevman 0:38ceb79fef03 220 unsigned char *output, size_t len, size_t *olen )
kevman 0:38ceb79fef03 221 {
kevman 0:38ceb79fef03 222 unsigned long timer = mbedtls_timing_hardclock();
kevman 0:38ceb79fef03 223 ((void) data);
kevman 0:38ceb79fef03 224 *olen = 0;
kevman 0:38ceb79fef03 225
kevman 0:38ceb79fef03 226 if( len < sizeof(unsigned long) )
kevman 0:38ceb79fef03 227 return( 0 );
kevman 0:38ceb79fef03 228
kevman 0:38ceb79fef03 229 memcpy( output, &timer, sizeof(unsigned long) );
kevman 0:38ceb79fef03 230 *olen = sizeof(unsigned long);
kevman 0:38ceb79fef03 231
kevman 0:38ceb79fef03 232 return( 0 );
kevman 0:38ceb79fef03 233 }
kevman 0:38ceb79fef03 234 #endif /* MBEDTLS_TIMING_C */
kevman 0:38ceb79fef03 235
kevman 0:38ceb79fef03 236 #if defined(MBEDTLS_HAVEGE_C)
kevman 0:38ceb79fef03 237 int mbedtls_havege_poll( void *data,
kevman 0:38ceb79fef03 238 unsigned char *output, size_t len, size_t *olen )
kevman 0:38ceb79fef03 239 {
kevman 0:38ceb79fef03 240 mbedtls_havege_state *hs = (mbedtls_havege_state *) data;
kevman 0:38ceb79fef03 241 *olen = 0;
kevman 0:38ceb79fef03 242
kevman 0:38ceb79fef03 243 if( mbedtls_havege_random( hs, output, len ) != 0 )
kevman 0:38ceb79fef03 244 return( MBEDTLS_ERR_ENTROPY_SOURCE_FAILED );
kevman 0:38ceb79fef03 245
kevman 0:38ceb79fef03 246 *olen = len;
kevman 0:38ceb79fef03 247
kevman 0:38ceb79fef03 248 return( 0 );
kevman 0:38ceb79fef03 249 }
kevman 0:38ceb79fef03 250 #endif /* MBEDTLS_HAVEGE_C */
kevman 0:38ceb79fef03 251
kevman 0:38ceb79fef03 252 #if defined(MBEDTLS_ENTROPY_NV_SEED)
kevman 0:38ceb79fef03 253 int mbedtls_nv_seed_poll( void *data,
kevman 0:38ceb79fef03 254 unsigned char *output, size_t len, size_t *olen )
kevman 0:38ceb79fef03 255 {
kevman 0:38ceb79fef03 256 unsigned char buf[MBEDTLS_ENTROPY_BLOCK_SIZE];
kevman 0:38ceb79fef03 257 size_t use_len = MBEDTLS_ENTROPY_BLOCK_SIZE;
kevman 0:38ceb79fef03 258 ((void) data);
kevman 0:38ceb79fef03 259
kevman 0:38ceb79fef03 260 memset( buf, 0, MBEDTLS_ENTROPY_BLOCK_SIZE );
kevman 0:38ceb79fef03 261
kevman 0:38ceb79fef03 262 if( mbedtls_nv_seed_read( buf, MBEDTLS_ENTROPY_BLOCK_SIZE ) < 0 )
kevman 0:38ceb79fef03 263 return( MBEDTLS_ERR_ENTROPY_SOURCE_FAILED );
kevman 0:38ceb79fef03 264
kevman 0:38ceb79fef03 265 if( len < use_len )
kevman 0:38ceb79fef03 266 use_len = len;
kevman 0:38ceb79fef03 267
kevman 0:38ceb79fef03 268 memcpy( output, buf, use_len );
kevman 0:38ceb79fef03 269 *olen = use_len;
kevman 0:38ceb79fef03 270
kevman 0:38ceb79fef03 271 return( 0 );
kevman 0:38ceb79fef03 272 }
kevman 0:38ceb79fef03 273 #endif /* MBEDTLS_ENTROPY_NV_SEED */
kevman 0:38ceb79fef03 274
kevman 0:38ceb79fef03 275 #endif /* MBEDTLS_ENTROPY_C */