erkin yucel / mbed-os

mbed os with nrf51 internal bandgap enabled to read battery level

Dependents:   BLE_file_test BLE_Blink ExternalEncoder

features/mbedtls/src/entropy_poll.c@0:f269e3021894, 2016-10-23 (annotated)

Committer:
elessair
Date:
Sun Oct 23 15:10:02 2016 +0000
Revision:
0:f269e3021894
Initial commit

Who changed what in which revision?

UserRevisionLine numberNew contents of line
elessair 0:f269e3021894 1 /*
elessair 0:f269e3021894 2 * Platform-specific and custom entropy polling functions
elessair 0:f269e3021894 3 *
elessair 0:f269e3021894 4 * Copyright (C) 2006-2016, ARM Limited, All Rights Reserved
elessair 0:f269e3021894 5 * SPDX-License-Identifier: Apache-2.0
elessair 0:f269e3021894 6 *
elessair 0:f269e3021894 7 * Licensed under the Apache License, Version 2.0 (the "License"); you may
elessair 0:f269e3021894 8 * not use this file except in compliance with the License.
elessair 0:f269e3021894 9 * You may obtain a copy of the License at
elessair 0:f269e3021894 10 *
elessair 0:f269e3021894 11 * http://www.apache.org/licenses/LICENSE-2.0
elessair 0:f269e3021894 12 *
elessair 0:f269e3021894 13 * Unless required by applicable law or agreed to in writing, software
elessair 0:f269e3021894 14 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
elessair 0:f269e3021894 15 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
elessair 0:f269e3021894 16 * See the License for the specific language governing permissions and
elessair 0:f269e3021894 17 * limitations under the License.
elessair 0:f269e3021894 18 *
elessair 0:f269e3021894 19 * This file is part of mbed TLS (https://tls.mbed.org)
elessair 0:f269e3021894 20 */
elessair 0:f269e3021894 21
elessair 0:f269e3021894 22 #if !defined(MBEDTLS_CONFIG_FILE)
elessair 0:f269e3021894 23 #include "mbedtls/config.h"
elessair 0:f269e3021894 24 #else
elessair 0:f269e3021894 25 #include MBEDTLS_CONFIG_FILE
elessair 0:f269e3021894 26 #endif
elessair 0:f269e3021894 27
elessair 0:f269e3021894 28 #if defined(MBEDTLS_ENTROPY_C)
elessair 0:f269e3021894 29
elessair 0:f269e3021894 30 #include "mbedtls/entropy.h"
elessair 0:f269e3021894 31 #include "mbedtls/entropy_poll.h"
elessair 0:f269e3021894 32
elessair 0:f269e3021894 33 #if defined(MBEDTLS_TIMING_C)
elessair 0:f269e3021894 34 #include <string.h>
elessair 0:f269e3021894 35 #include "mbedtls/timing.h"
elessair 0:f269e3021894 36 #endif
elessair 0:f269e3021894 37 #if defined(MBEDTLS_HAVEGE_C)
elessair 0:f269e3021894 38 #include "mbedtls/havege.h"
elessair 0:f269e3021894 39 #endif
elessair 0:f269e3021894 40 #if defined(MBEDTLS_ENTROPY_NV_SEED)
elessair 0:f269e3021894 41 #include "mbedtls/platform.h"
elessair 0:f269e3021894 42 #endif
elessair 0:f269e3021894 43
elessair 0:f269e3021894 44 #if !defined(MBEDTLS_NO_PLATFORM_ENTROPY)
elessair 0:f269e3021894 45
elessair 0:f269e3021894 46 #if !defined(unix) && !defined(__unix__) && !defined(__unix) && \
elessair 0:f269e3021894 47 !defined(__APPLE__) && !defined(_WIN32)
elessair 0:f269e3021894 48 #error "Platform entropy sources only work on Unix and Windows, see MBEDTLS_NO_PLATFORM_ENTROPY in config.h"
elessair 0:f269e3021894 49 #endif
elessair 0:f269e3021894 50
elessair 0:f269e3021894 51 #if defined(_WIN32) && !defined(EFIX64) && !defined(EFI32)
elessair 0:f269e3021894 52
elessair 0:f269e3021894 53 #if !defined(_WIN32_WINNT)
elessair 0:f269e3021894 54 #define _WIN32_WINNT 0x0400
elessair 0:f269e3021894 55 #endif
elessair 0:f269e3021894 56 #include <windows.h>
elessair 0:f269e3021894 57 #include <wincrypt.h>
elessair 0:f269e3021894 58
elessair 0:f269e3021894 59 int mbedtls_platform_entropy_poll( void *data, unsigned char *output, size_t len,
elessair 0:f269e3021894 60 size_t *olen )
elessair 0:f269e3021894 61 {
elessair 0:f269e3021894 62 HCRYPTPROV provider;
elessair 0:f269e3021894 63 ((void) data);
elessair 0:f269e3021894 64 *olen = 0;
elessair 0:f269e3021894 65
elessair 0:f269e3021894 66 if( CryptAcquireContext( &provider, NULL, NULL,
elessair 0:f269e3021894 67 PROV_RSA_FULL, CRYPT_VERIFYCONTEXT ) == FALSE )
elessair 0:f269e3021894 68 {
elessair 0:f269e3021894 69 return( MBEDTLS_ERR_ENTROPY_SOURCE_FAILED );
elessair 0:f269e3021894 70 }
elessair 0:f269e3021894 71
elessair 0:f269e3021894 72 if( CryptGenRandom( provider, (DWORD) len, output ) == FALSE )
elessair 0:f269e3021894 73 {
elessair 0:f269e3021894 74 CryptReleaseContext( provider, 0 );
elessair 0:f269e3021894 75 return( MBEDTLS_ERR_ENTROPY_SOURCE_FAILED );
elessair 0:f269e3021894 76 }
elessair 0:f269e3021894 77
elessair 0:f269e3021894 78 CryptReleaseContext( provider, 0 );
elessair 0:f269e3021894 79 *olen = len;
elessair 0:f269e3021894 80
elessair 0:f269e3021894 81 return( 0 );
elessair 0:f269e3021894 82 }
elessair 0:f269e3021894 83 #else /* _WIN32 && !EFIX64 && !EFI32 */
elessair 0:f269e3021894 84
elessair 0:f269e3021894 85 /*
elessair 0:f269e3021894 86 * Test for Linux getrandom() support.
elessair 0:f269e3021894 87 * Since there is no wrapper in the libc yet, use the generic syscall wrapper
elessair 0:f269e3021894 88 * available in GNU libc and compatible libc's (eg uClibc).
elessair 0:f269e3021894 89 */
elessair 0:f269e3021894 90 #if defined(__linux__) && defined(__GLIBC__)
elessair 0:f269e3021894 91 #include <unistd.h>
elessair 0:f269e3021894 92 #include <sys/syscall.h>
elessair 0:f269e3021894 93 #if defined(SYS_getrandom)
elessair 0:f269e3021894 94 #define HAVE_GETRANDOM
elessair 0:f269e3021894 95
elessair 0:f269e3021894 96 static int getrandom_wrapper( void *buf, size_t buflen, unsigned int flags )
elessair 0:f269e3021894 97 {
elessair 0:f269e3021894 98 /* MemSan cannot understand that the syscall writes to the buffer */
elessair 0:f269e3021894 99 #if defined(__has_feature)
elessair 0:f269e3021894 100 #if __has_feature(memory_sanitizer)
elessair 0:f269e3021894 101 memset( buf, 0, buflen );
elessair 0:f269e3021894 102 #endif
elessair 0:f269e3021894 103 #endif
elessair 0:f269e3021894 104
elessair 0:f269e3021894 105 return( syscall( SYS_getrandom, buf, buflen, flags ) );
elessair 0:f269e3021894 106 }
elessair 0:f269e3021894 107
elessair 0:f269e3021894 108 #include <sys/utsname.h>
elessair 0:f269e3021894 109 /* Check if version is at least 3.17.0 */
elessair 0:f269e3021894 110 static int check_version_3_17_plus( void )
elessair 0:f269e3021894 111 {
elessair 0:f269e3021894 112 int minor;
elessair 0:f269e3021894 113 struct utsname un;
elessair 0:f269e3021894 114 const char *ver;
elessair 0:f269e3021894 115
elessair 0:f269e3021894 116 /* Get version information */
elessair 0:f269e3021894 117 uname(&un);
elessair 0:f269e3021894 118 ver = un.release;
elessair 0:f269e3021894 119
elessair 0:f269e3021894 120 /* Check major version; assume a single digit */
elessair 0:f269e3021894 121 if( ver[0] < '3' || ver[0] > '9' || ver [1] != '.' )
elessair 0:f269e3021894 122 return( -1 );
elessair 0:f269e3021894 123
elessair 0:f269e3021894 124 if( ver[0] - '0' > 3 )
elessair 0:f269e3021894 125 return( 0 );
elessair 0:f269e3021894 126
elessair 0:f269e3021894 127 /* Ok, so now we know major == 3, check minor.
elessair 0:f269e3021894 128 * Assume 1 or 2 digits. */
elessair 0:f269e3021894 129 if( ver[2] < '0' || ver[2] > '9' )
elessair 0:f269e3021894 130 return( -1 );
elessair 0:f269e3021894 131
elessair 0:f269e3021894 132 minor = ver[2] - '0';
elessair 0:f269e3021894 133
elessair 0:f269e3021894 134 if( ver[3] >= '0' && ver[3] <= '9' )
elessair 0:f269e3021894 135 minor = 10 * minor + ver[3] - '0';
elessair 0:f269e3021894 136 else if( ver [3] != '.' )
elessair 0:f269e3021894 137 return( -1 );
elessair 0:f269e3021894 138
elessair 0:f269e3021894 139 if( minor < 17 )
elessair 0:f269e3021894 140 return( -1 );
elessair 0:f269e3021894 141
elessair 0:f269e3021894 142 return( 0 );
elessair 0:f269e3021894 143 }
elessair 0:f269e3021894 144 static int has_getrandom = -1;
elessair 0:f269e3021894 145 #endif /* SYS_getrandom */
elessair 0:f269e3021894 146 #endif /* __linux__ */
elessair 0:f269e3021894 147
elessair 0:f269e3021894 148 #include <stdio.h>
elessair 0:f269e3021894 149
elessair 0:f269e3021894 150 int mbedtls_platform_entropy_poll( void *data,
elessair 0:f269e3021894 151 unsigned char *output, size_t len, size_t *olen )
elessair 0:f269e3021894 152 {
elessair 0:f269e3021894 153 FILE *file;
elessair 0:f269e3021894 154 size_t read_len;
elessair 0:f269e3021894 155 ((void) data);
elessair 0:f269e3021894 156
elessair 0:f269e3021894 157 #if defined(HAVE_GETRANDOM)
elessair 0:f269e3021894 158 if( has_getrandom == -1 )
elessair 0:f269e3021894 159 has_getrandom = ( check_version_3_17_plus() == 0 );
elessair 0:f269e3021894 160
elessair 0:f269e3021894 161 if( has_getrandom )
elessair 0:f269e3021894 162 {
elessair 0:f269e3021894 163 int ret;
elessair 0:f269e3021894 164
elessair 0:f269e3021894 165 if( ( ret = getrandom_wrapper( output, len, 0 ) ) < 0 )
elessair 0:f269e3021894 166 return( MBEDTLS_ERR_ENTROPY_SOURCE_FAILED );
elessair 0:f269e3021894 167
elessair 0:f269e3021894 168 *olen = ret;
elessair 0:f269e3021894 169 return( 0 );
elessair 0:f269e3021894 170 }
elessair 0:f269e3021894 171 #endif /* HAVE_GETRANDOM */
elessair 0:f269e3021894 172
elessair 0:f269e3021894 173 *olen = 0;
elessair 0:f269e3021894 174
elessair 0:f269e3021894 175 file = fopen( "/dev/urandom", "rb" );
elessair 0:f269e3021894 176 if( file == NULL )
elessair 0:f269e3021894 177 return( MBEDTLS_ERR_ENTROPY_SOURCE_FAILED );
elessair 0:f269e3021894 178
elessair 0:f269e3021894 179 read_len = fread( output, 1, len, file );
elessair 0:f269e3021894 180 if( read_len != len )
elessair 0:f269e3021894 181 {
elessair 0:f269e3021894 182 fclose( file );
elessair 0:f269e3021894 183 return( MBEDTLS_ERR_ENTROPY_SOURCE_FAILED );
elessair 0:f269e3021894 184 }
elessair 0:f269e3021894 185
elessair 0:f269e3021894 186 fclose( file );
elessair 0:f269e3021894 187 *olen = len;
elessair 0:f269e3021894 188
elessair 0:f269e3021894 189 return( 0 );
elessair 0:f269e3021894 190 }
elessair 0:f269e3021894 191 #endif /* _WIN32 && !EFIX64 && !EFI32 */
elessair 0:f269e3021894 192 #endif /* !MBEDTLS_NO_PLATFORM_ENTROPY */
elessair 0:f269e3021894 193
elessair 0:f269e3021894 194 #if defined(MBEDTLS_TEST_NULL_ENTROPY)
elessair 0:f269e3021894 195 int mbedtls_null_entropy_poll( void *data,
elessair 0:f269e3021894 196 unsigned char *output, size_t len, size_t *olen )
elessair 0:f269e3021894 197 {
elessair 0:f269e3021894 198 ((void) data);
elessair 0:f269e3021894 199 ((void) output);
elessair 0:f269e3021894 200 *olen = 0;
elessair 0:f269e3021894 201
elessair 0:f269e3021894 202 if( len < sizeof(unsigned char) )
elessair 0:f269e3021894 203 return( 0 );
elessair 0:f269e3021894 204
elessair 0:f269e3021894 205 *olen = sizeof(unsigned char);
elessair 0:f269e3021894 206
elessair 0:f269e3021894 207 return( 0 );
elessair 0:f269e3021894 208 }
elessair 0:f269e3021894 209 #endif
elessair 0:f269e3021894 210
elessair 0:f269e3021894 211 #if defined(MBEDTLS_TIMING_C)
elessair 0:f269e3021894 212 int mbedtls_hardclock_poll( void *data,
elessair 0:f269e3021894 213 unsigned char *output, size_t len, size_t *olen )
elessair 0:f269e3021894 214 {
elessair 0:f269e3021894 215 unsigned long timer = mbedtls_timing_hardclock();
elessair 0:f269e3021894 216 ((void) data);
elessair 0:f269e3021894 217 *olen = 0;
elessair 0:f269e3021894 218
elessair 0:f269e3021894 219 if( len < sizeof(unsigned long) )
elessair 0:f269e3021894 220 return( 0 );
elessair 0:f269e3021894 221
elessair 0:f269e3021894 222 memcpy( output, &timer, sizeof(unsigned long) );
elessair 0:f269e3021894 223 *olen = sizeof(unsigned long);
elessair 0:f269e3021894 224
elessair 0:f269e3021894 225 return( 0 );
elessair 0:f269e3021894 226 }
elessair 0:f269e3021894 227 #endif /* MBEDTLS_TIMING_C */
elessair 0:f269e3021894 228
elessair 0:f269e3021894 229 #if defined(MBEDTLS_HAVEGE_C)
elessair 0:f269e3021894 230 int mbedtls_havege_poll( void *data,
elessair 0:f269e3021894 231 unsigned char *output, size_t len, size_t *olen )
elessair 0:f269e3021894 232 {
elessair 0:f269e3021894 233 mbedtls_havege_state *hs = (mbedtls_havege_state *) data;
elessair 0:f269e3021894 234 *olen = 0;
elessair 0:f269e3021894 235
elessair 0:f269e3021894 236 if( mbedtls_havege_random( hs, output, len ) != 0 )
elessair 0:f269e3021894 237 return( MBEDTLS_ERR_ENTROPY_SOURCE_FAILED );
elessair 0:f269e3021894 238
elessair 0:f269e3021894 239 *olen = len;
elessair 0:f269e3021894 240
elessair 0:f269e3021894 241 return( 0 );
elessair 0:f269e3021894 242 }
elessair 0:f269e3021894 243 #endif /* MBEDTLS_HAVEGE_C */
elessair 0:f269e3021894 244
elessair 0:f269e3021894 245 #if defined(MBEDTLS_ENTROPY_NV_SEED)
elessair 0:f269e3021894 246 int mbedtls_nv_seed_poll( void *data,
elessair 0:f269e3021894 247 unsigned char *output, size_t len, size_t *olen )
elessair 0:f269e3021894 248 {
elessair 0:f269e3021894 249 unsigned char buf[MBEDTLS_ENTROPY_BLOCK_SIZE];
elessair 0:f269e3021894 250 size_t use_len = MBEDTLS_ENTROPY_BLOCK_SIZE;
elessair 0:f269e3021894 251 ((void) data);
elessair 0:f269e3021894 252
elessair 0:f269e3021894 253 memset( buf, 0, MBEDTLS_ENTROPY_BLOCK_SIZE );
elessair 0:f269e3021894 254
elessair 0:f269e3021894 255 if( mbedtls_nv_seed_read( buf, MBEDTLS_ENTROPY_BLOCK_SIZE ) < 0 )
elessair 0:f269e3021894 256 return( MBEDTLS_ERR_ENTROPY_SOURCE_FAILED );
elessair 0:f269e3021894 257
elessair 0:f269e3021894 258 if( len < use_len )
elessair 0:f269e3021894 259 use_len = len;
elessair 0:f269e3021894 260
elessair 0:f269e3021894 261 memcpy( output, buf, use_len );
elessair 0:f269e3021894 262 *olen = use_len;
elessair 0:f269e3021894 263
elessair 0:f269e3021894 264 return( 0 );
elessair 0:f269e3021894 265 }
elessair 0:f269e3021894 266 #endif /* MBEDTLS_ENTROPY_NV_SEED */
elessair 0:f269e3021894 267
elessair 0:f269e3021894 268 #endif /* MBEDTLS_ENTROPY_C */