1 /**
2 * \file random.c
3 *
4 * \brief This file contains the helper functions to generate random numbers
5 * for the purpose of testing.
6 */
7
8 /*
9 * Copyright The Mbed TLS Contributors
10 * SPDX-License-Identifier: Apache-2.0
11 *
12 * Licensed under the Apache License, Version 2.0 (the "License"); you may
13 * not use this file except in compliance with the License.
14 * You may obtain a copy of the License at
15 *
16 * http://www.apache.org/licenses/LICENSE-2.0
17 *
18 * Unless required by applicable law or agreed to in writing, software
19 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
20 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
21 * See the License for the specific language governing permissions and
22 * limitations under the License.
23 */
24
25 /*
26 * for arc4random_buf() from <stdlib.h>
27 */
28 #if defined(__NetBSD__)
29 #define _NETBSD_SOURCE 1
30 #elif defined(__OpenBSD__)
31 #define _BSD_SOURCE 1
32 #endif
33
34 #include <test/macros.h>
35 #include <test/random.h>
36 #include <string.h>
37
38 #include <mbedtls/entropy.h>
39 #include "../../library/alignment.h"
40
mbedtls_test_rnd_std_rand(void * rng_state,unsigned char * output,size_t len)41 int mbedtls_test_rnd_std_rand(void *rng_state,
42 unsigned char *output,
43 size_t len)
44 {
45 #if !defined(__OpenBSD__) && !defined(__NetBSD__)
46 size_t i;
47
48 if (rng_state != NULL) {
49 rng_state = NULL;
50 }
51
52 for (i = 0; i < len; ++i) {
53 output[i] = rand();
54 }
55 #else
56 if (rng_state != NULL) {
57 rng_state = NULL;
58 }
59
60 arc4random_buf(output, len);
61 #endif /* !OpenBSD && !NetBSD */
62
63 return 0;
64 }
65
mbedtls_test_rnd_zero_rand(void * rng_state,unsigned char * output,size_t len)66 int mbedtls_test_rnd_zero_rand(void *rng_state,
67 unsigned char *output,
68 size_t len)
69 {
70 if (rng_state != NULL) {
71 rng_state = NULL;
72 }
73
74 memset(output, 0, len);
75
76 return 0;
77 }
78
mbedtls_test_rnd_buffer_rand(void * rng_state,unsigned char * output,size_t len)79 int mbedtls_test_rnd_buffer_rand(void *rng_state,
80 unsigned char *output,
81 size_t len)
82 {
83 mbedtls_test_rnd_buf_info *info = (mbedtls_test_rnd_buf_info *) rng_state;
84 size_t use_len;
85
86 if (rng_state == NULL) {
87 return mbedtls_test_rnd_std_rand(NULL, output, len);
88 }
89
90 use_len = len;
91 if (len > info->length) {
92 use_len = info->length;
93 }
94
95 if (use_len) {
96 memcpy(output, info->buf, use_len);
97 info->buf += use_len;
98 info->length -= use_len;
99 }
100
101 if (len - use_len > 0) {
102 if (info->fallback_f_rng != NULL) {
103 return info->fallback_f_rng(info->fallback_p_rng,
104 output + use_len,
105 len - use_len);
106 } else {
107 return MBEDTLS_ERR_ENTROPY_SOURCE_FAILED;
108 }
109 }
110
111 return 0;
112 }
113
mbedtls_test_rnd_pseudo_rand(void * rng_state,unsigned char * output,size_t len)114 int mbedtls_test_rnd_pseudo_rand(void *rng_state,
115 unsigned char *output,
116 size_t len)
117 {
118 mbedtls_test_rnd_pseudo_info *info =
119 (mbedtls_test_rnd_pseudo_info *) rng_state;
120 uint32_t i, *k, sum, delta = 0x9E3779B9;
121 unsigned char result[4], *out = output;
122
123 if (rng_state == NULL) {
124 return mbedtls_test_rnd_std_rand(NULL, output, len);
125 }
126
127 k = info->key;
128
129 while (len > 0) {
130 size_t use_len = (len > 4) ? 4 : len;
131 sum = 0;
132
133 for (i = 0; i < 32; i++) {
134 info->v0 += (((info->v1 << 4) ^ (info->v1 >> 5))
135 + info->v1) ^ (sum + k[sum & 3]);
136 sum += delta;
137 info->v1 += (((info->v0 << 4) ^ (info->v0 >> 5))
138 + info->v0) ^ (sum + k[(sum>>11) & 3]);
139 }
140
141 MBEDTLS_PUT_UINT32_BE(info->v0, result, 0);
142 memcpy(out, result, use_len);
143 len -= use_len;
144 out += 4;
145 }
146
147 return 0;
148 }
149