1 | /*
|
---|
2 | * Platform-specific and custom entropy polling functions
|
---|
3 | *
|
---|
4 | * Copyright (C) 2006-2016, ARM Limited, All Rights Reserved
|
---|
5 | * 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.
|
---|
18 | *
|
---|
19 | * This file is part of mbed TLS (https://tls.mbed.org)
|
---|
20 | */
|
---|
21 |
|
---|
22 | #if defined(__linux__)
|
---|
23 | /* Ensure that syscall() is available even when compiling with -std=c99 */
|
---|
24 | #define _GNU_SOURCE
|
---|
25 | #endif
|
---|
26 |
|
---|
27 | #if !defined(MBEDTLS_CONFIG_FILE)
|
---|
28 | #include "mbedtls/config.h"
|
---|
29 | #else
|
---|
30 | #include MBEDTLS_CONFIG_FILE
|
---|
31 | #endif
|
---|
32 |
|
---|
33 | #include <string.h>
|
---|
34 |
|
---|
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)
|
---|
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) && \
|
---|
53 | !defined(__APPLE__) && !defined(_WIN32) && !defined(__QNXNTO__) && \
|
---|
54 | !defined(__HAIKU__)
|
---|
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
|
---|
102 | #include <errno.h>
|
---|
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
|
---|
112 | return( syscall( SYS_getrandom, buf, buflen, flags ) );
|
---|
113 | }
|
---|
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;
|
---|
124 | int ret;
|
---|
125 | ((void) data);
|
---|
126 |
|
---|
127 | #if defined(HAVE_GETRANDOM)
|
---|
128 | ret = getrandom_wrapper( output, len, 0 );
|
---|
129 | if( ret >= 0 )
|
---|
130 | {
|
---|
131 | *olen = ret;
|
---|
132 | return( 0 );
|
---|
133 | }
|
---|
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);
|
---|
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 */
|
---|