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Paul Bakker6083fd22011-12-03 21:45:14 +00001/*
2 * Platform-specific and custom entropy polling functions
3 *
Paul Bakker9988d6b2016-06-01 11:29:42 +01004 * Copyright (C) 2006-2016, ARM Limited, All Rights Reserved
Manuel Pégourié-Gonnard37ff1402015-09-04 14:21:07 +02005 * SPDX-License-Identifier: Apache-2.0
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.
Paul Bakker6083fd22011-12-03 21:45:14 +000018 *
Manuel Pégourié-Gonnardfe446432015-03-06 13:17:10 +000019 * This file is part of mbed TLS (https://tls.mbed.org)
Paul Bakker6083fd22011-12-03 21:45:14 +000020 */
21
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +020022#if !defined(MBEDTLS_CONFIG_FILE)
Manuel Pégourié-Gonnard7f809972015-03-09 17:05:11 +000023#include "mbedtls/config.h"
Manuel Pégourié-Gonnardcef4ad22014-04-29 12:39:06 +020024#else
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +020025#include MBEDTLS_CONFIG_FILE
Manuel Pégourié-Gonnardcef4ad22014-04-29 12:39:06 +020026#endif
Paul Bakker6083fd22011-12-03 21:45:14 +000027
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +020028#if defined(MBEDTLS_ENTROPY_C)
Paul Bakker6083fd22011-12-03 21:45:14 +000029
Manuel Pégourié-Gonnard7f809972015-03-09 17:05:11 +000030#include "mbedtls/entropy.h"
31#include "mbedtls/entropy_poll.h"
Paul Bakker6083fd22011-12-03 21:45:14 +000032
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +020033#if defined(MBEDTLS_TIMING_C)
Rich Evans00ab4702015-02-06 13:43:58 +000034#include <string.h>
Manuel Pégourié-Gonnard7f809972015-03-09 17:05:11 +000035#include "mbedtls/timing.h"
Paul Bakker6083fd22011-12-03 21:45:14 +000036#endif
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +020037#if defined(MBEDTLS_HAVEGE_C)
Manuel Pégourié-Gonnard7f809972015-03-09 17:05:11 +000038#include "mbedtls/havege.h"
Paul Bakker6083fd22011-12-03 21:45:14 +000039#endif
Paul Bakker9988d6b2016-06-01 11:29:42 +010040#if defined(MBEDTLS_ENTROPY_NV_SEED)
41#include "mbedtls/platform.h"
42#endif
Paul Bakker6083fd22011-12-03 21:45:14 +000043
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +020044#if !defined(MBEDTLS_NO_PLATFORM_ENTROPY)
Manuel Pégourié-Gonnard325ce092016-02-22 10:33:34 +010045
46#if !defined(unix) && !defined(__unix__) && !defined(__unix) && \
47 !defined(__APPLE__) && !defined(_WIN32)
48#error "Platform entropy sources only work on Unix and Windows, see MBEDTLS_NO_PLATFORM_ENTROPY in config.h"
49#endif
50
Paul Bakkerfa6a6202013-10-28 18:48:30 +010051#if defined(_WIN32) && !defined(EFIX64) && !defined(EFI32)
Paul Bakker6083fd22011-12-03 21:45:14 +000052
Paul Bakker6083fd22011-12-03 21:45:14 +000053#if !defined(_WIN32_WINNT)
54#define _WIN32_WINNT 0x0400
55#endif
Paul Bakker4a2bd0d2012-11-02 11:06:08 +000056#include <windows.h>
Paul Bakker6083fd22011-12-03 21:45:14 +000057#include <wincrypt.h>
58
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +020059int mbedtls_platform_entropy_poll( void *data, unsigned char *output, size_t len,
Paul Bakker6083fd22011-12-03 21:45:14 +000060 size_t *olen )
61{
62 HCRYPTPROV provider;
Paul Bakker6bcfc672011-12-05 13:54:00 +000063 ((void) data);
Paul Bakker6083fd22011-12-03 21:45:14 +000064 *olen = 0;
65
66 if( CryptAcquireContext( &provider, NULL, NULL,
67 PROV_RSA_FULL, CRYPT_VERIFYCONTEXT ) == FALSE )
68 {
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +020069 return( MBEDTLS_ERR_ENTROPY_SOURCE_FAILED );
Paul Bakker6083fd22011-12-03 21:45:14 +000070 }
71
Paul Bakkerb9cfaa02013-10-11 18:58:55 +020072 if( CryptGenRandom( provider, (DWORD) len, output ) == FALSE )
Attila Molnar2791ba12016-01-26 11:39:26 +010073 {
74 CryptReleaseContext( provider, 0 );
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +020075 return( MBEDTLS_ERR_ENTROPY_SOURCE_FAILED );
Attila Molnar2791ba12016-01-26 11:39:26 +010076 }
Paul Bakker6083fd22011-12-03 21:45:14 +000077
78 CryptReleaseContext( provider, 0 );
79 *olen = len;
80
81 return( 0 );
82}
Paul Bakker9af723c2014-05-01 13:03:14 +020083#else /* _WIN32 && !EFIX64 && !EFI32 */
Paul Bakker6083fd22011-12-03 21:45:14 +000084
Manuel Pégourié-Gonnard18292452015-01-09 14:34:13 +010085/*
86 * Test for Linux getrandom() support.
87 * Since there is no wrapper in the libc yet, use the generic syscall wrapper
88 * available in GNU libc and compatible libc's (eg uClibc).
89 */
90#if defined(__linux__) && defined(__GLIBC__)
Manuel Pégourié-Gonnard18292452015-01-09 14:34:13 +010091#include <unistd.h>
92#include <sys/syscall.h>
93#if defined(SYS_getrandom)
94#define HAVE_GETRANDOM
Manuel Pégourié-Gonnardbcf13ba2015-06-22 18:06:17 +020095
Manuel Pégourié-Gonnard18292452015-01-09 14:34:13 +010096static int getrandom_wrapper( void *buf, size_t buflen, unsigned int flags )
97{
Manuel Pégourié-Gonnardbcf13ba2015-06-22 18:06:17 +020098 /* MemSan cannot understand that the syscall writes to the buffer */
99#if defined(__has_feature)
100#if __has_feature(memory_sanitizer)
101 memset( buf, 0, buflen );
102#endif
103#endif
104
Manuel Pégourié-Gonnard18292452015-01-09 14:34:13 +0100105 return( syscall( SYS_getrandom, buf, buflen, flags ) );
106}
Manuel Pégourié-Gonnard18292452015-01-09 14:34:13 +0100107
Manuel Pégourié-Gonnardd97828e2015-04-29 14:03:28 +0200108#include <sys/utsname.h>
109/* Check if version is at least 3.17.0 */
110static int check_version_3_17_plus( void )
Manuel Pégourié-Gonnard18292452015-01-09 14:34:13 +0100111{
Manuel Pégourié-Gonnardd97828e2015-04-29 14:03:28 +0200112 int minor;
113 struct utsname un;
114 const char *ver;
Manuel Pégourié-Gonnard18292452015-01-09 14:34:13 +0100115
Manuel Pégourié-Gonnardd97828e2015-04-29 14:03:28 +0200116 /* Get version information */
117 uname(&un);
118 ver = un.release;
Manuel Pégourié-Gonnard18292452015-01-09 14:34:13 +0100119
Manuel Pégourié-Gonnardd97828e2015-04-29 14:03:28 +0200120 /* Check major version; assume a single digit */
121 if( ver[0] < '3' || ver[0] > '9' || ver [1] != '.' )
122 return( -1 );
123
124 if( ver[0] - '0' > 3 )
125 return( 0 );
126
127 /* Ok, so now we know major == 3, check minor.
128 * Assume 1 or 2 digits. */
129 if( ver[2] < '0' || ver[2] > '9' )
130 return( -1 );
131
132 minor = ver[2] - '0';
133
134 if( ver[3] >= '0' && ver[3] <= '9' )
135 minor = 10 * minor + ver[3] - '0';
136 else if( ver [3] != '.' )
137 return( -1 );
138
139 if( minor < 17 )
140 return( -1 );
141
Manuel Pégourié-Gonnard18292452015-01-09 14:34:13 +0100142 return( 0 );
143}
Manuel Pégourié-Gonnardd97828e2015-04-29 14:03:28 +0200144static int has_getrandom = -1;
145#endif /* SYS_getrandom */
146#endif /* __linux__ */
Manuel Pégourié-Gonnard18292452015-01-09 14:34:13 +0100147
Paul Bakker6083fd22011-12-03 21:45:14 +0000148#include <stdio.h>
149
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +0200150int mbedtls_platform_entropy_poll( void *data,
Paul Bakker6083fd22011-12-03 21:45:14 +0000151 unsigned char *output, size_t len, size_t *olen )
152{
153 FILE *file;
Manuel Pégourié-Gonnardea356662015-08-27 12:02:40 +0200154 size_t read_len;
Paul Bakker6083fd22011-12-03 21:45:14 +0000155 ((void) data);
156
Manuel Pégourié-Gonnardd97828e2015-04-29 14:03:28 +0200157#if defined(HAVE_GETRANDOM)
158 if( has_getrandom == -1 )
159 has_getrandom = ( check_version_3_17_plus() == 0 );
160
161 if( has_getrandom )
162 {
163 int ret;
164
165 if( ( ret = getrandom_wrapper( output, len, 0 ) ) < 0 )
Manuel Pégourié-Gonnard9f145de2015-05-04 15:03:50 +0200166 return( MBEDTLS_ERR_ENTROPY_SOURCE_FAILED );
Manuel Pégourié-Gonnardd97828e2015-04-29 14:03:28 +0200167
168 *olen = ret;
169 return( 0 );
170 }
171#endif /* HAVE_GETRANDOM */
172
Paul Bakker6083fd22011-12-03 21:45:14 +0000173 *olen = 0;
174
175 file = fopen( "/dev/urandom", "rb" );
176 if( file == NULL )
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +0200177 return( MBEDTLS_ERR_ENTROPY_SOURCE_FAILED );
Paul Bakker9af723c2014-05-01 13:03:14 +0200178
Manuel Pégourié-Gonnardea356662015-08-27 12:02:40 +0200179 read_len = fread( output, 1, len, file );
180 if( read_len != len )
Paul Bakker6083fd22011-12-03 21:45:14 +0000181 {
182 fclose( file );
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +0200183 return( MBEDTLS_ERR_ENTROPY_SOURCE_FAILED );
Paul Bakker6083fd22011-12-03 21:45:14 +0000184 }
185
186 fclose( file );
187 *olen = len;
188
189 return( 0 );
190}
Paul Bakker9af723c2014-05-01 13:03:14 +0200191#endif /* _WIN32 && !EFIX64 && !EFI32 */
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +0200192#endif /* !MBEDTLS_NO_PLATFORM_ENTROPY */
Paul Bakker6083fd22011-12-03 21:45:14 +0000193
Janos Follath53de7842016-06-08 15:29:18 +0100194#if defined(MBEDTLS_TEST_WO_ENTROPY)
195int mbedtls_zero_entropy_poll( void *data,
196 unsigned char *output, size_t len, size_t *olen )
197{
198 ((void) data);
199 *olen = 0;
200
201 if( len < sizeof(unsigned char) )
202 return( 0 );
203
204 *olen = sizeof(unsigned char);
205
206 return( 0 );
207}
208#endif
209
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +0200210#if defined(MBEDTLS_TIMING_C)
211int mbedtls_hardclock_poll( void *data,
Paul Bakker6083fd22011-12-03 21:45:14 +0000212 unsigned char *output, size_t len, size_t *olen )
213{
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +0200214 unsigned long timer = mbedtls_timing_hardclock();
Paul Bakker6083fd22011-12-03 21:45:14 +0000215 ((void) data);
216 *olen = 0;
217
218 if( len < sizeof(unsigned long) )
219 return( 0 );
220
221 memcpy( output, &timer, sizeof(unsigned long) );
222 *olen = sizeof(unsigned long);
223
224 return( 0 );
225}
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +0200226#endif /* MBEDTLS_TIMING_C */
Paul Bakker6083fd22011-12-03 21:45:14 +0000227
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +0200228#if defined(MBEDTLS_HAVEGE_C)
229int mbedtls_havege_poll( void *data,
Paul Bakker6083fd22011-12-03 21:45:14 +0000230 unsigned char *output, size_t len, size_t *olen )
231{
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +0200232 mbedtls_havege_state *hs = (mbedtls_havege_state *) data;
Paul Bakker6083fd22011-12-03 21:45:14 +0000233 *olen = 0;
234
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +0200235 if( mbedtls_havege_random( hs, output, len ) != 0 )
236 return( MBEDTLS_ERR_ENTROPY_SOURCE_FAILED );
Paul Bakker6083fd22011-12-03 21:45:14 +0000237
238 *olen = len;
239
240 return( 0 );
241}
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +0200242#endif /* MBEDTLS_HAVEGE_C */
Paul Bakker6083fd22011-12-03 21:45:14 +0000243
Paul Bakker9988d6b2016-06-01 11:29:42 +0100244#if defined(MBEDTLS_ENTROPY_NV_SEED)
245int mbedtls_nv_seed_poll( void *data,
246 unsigned char *output, size_t len, size_t *olen )
247{
248 unsigned char buf[MBEDTLS_ENTROPY_BLOCK_SIZE];
249 size_t use_len = MBEDTLS_ENTROPY_BLOCK_SIZE;
250 ((void) data);
251
252 memset( buf, 0, MBEDTLS_ENTROPY_BLOCK_SIZE );
253
254 if( mbedtls_nv_seed_read( buf, MBEDTLS_ENTROPY_BLOCK_SIZE ) < 0 )
255 return( MBEDTLS_ERR_ENTROPY_SOURCE_FAILED );
256
257 if( len < use_len )
258 use_len = len;
259
260 memcpy( output, buf, use_len );
261 *olen = use_len;
262
263 return( 0 );
264}
265#endif /* MBEDTLS_ENTROPY_NV_SEED */
266
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +0200267#endif /* MBEDTLS_ENTROPY_C */