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 OR GPL-2.0-or-later
11 */
12
13 /*
14 * for arc4random_buf() from <stdlib.h>
15 */
16 #if defined(__NetBSD__)
17 #define _NETBSD_SOURCE 1
18 #elif defined(__OpenBSD__)
19 #define _BSD_SOURCE 1
20 #endif
21
22 #include <test/macros.h>
23 #include <test/random.h>
24 #include <string.h>
25
26 #include <mbedtls/entropy.h>
27 #include <alignment.h>
28
mbedtls_test_rnd_std_rand(void * rng_state,unsigned char * output,size_t len)29 int mbedtls_test_rnd_std_rand(void *rng_state,
30 unsigned char *output,
31 size_t len)
32 {
33 #if !defined(__OpenBSD__) && !defined(__NetBSD__)
34 size_t i;
35
36 if (rng_state != NULL) {
37 rng_state = NULL;
38 }
39
40 for (i = 0; i < len; ++i) {
41 output[i] = rand();
42 }
43 #else
44 if (rng_state != NULL) {
45 rng_state = NULL;
46 }
47
48 arc4random_buf(output, len);
49 #endif /* !OpenBSD && !NetBSD */
50
51 return 0;
52 }
53
mbedtls_test_rnd_zero_rand(void * rng_state,unsigned char * output,size_t len)54 int mbedtls_test_rnd_zero_rand(void *rng_state,
55 unsigned char *output,
56 size_t len)
57 {
58 if (rng_state != NULL) {
59 rng_state = NULL;
60 }
61
62 memset(output, 0, len);
63
64 return 0;
65 }
66
mbedtls_test_rnd_buffer_rand(void * rng_state,unsigned char * output,size_t len)67 int mbedtls_test_rnd_buffer_rand(void *rng_state,
68 unsigned char *output,
69 size_t len)
70 {
71 mbedtls_test_rnd_buf_info *info = (mbedtls_test_rnd_buf_info *) rng_state;
72 size_t use_len;
73
74 if (rng_state == NULL) {
75 return mbedtls_test_rnd_std_rand(NULL, output, len);
76 }
77
78 use_len = len;
79 if (len > info->length) {
80 use_len = info->length;
81 }
82
83 if (use_len) {
84 memcpy(output, info->buf, use_len);
85 info->buf += use_len;
86 info->length -= use_len;
87 }
88
89 if (len - use_len > 0) {
90 if (info->fallback_f_rng != NULL) {
91 return info->fallback_f_rng(info->fallback_p_rng,
92 output + use_len,
93 len - use_len);
94 } else {
95 return MBEDTLS_ERR_ENTROPY_SOURCE_FAILED;
96 }
97 }
98
99 return 0;
100 }
101
mbedtls_test_rnd_pseudo_rand(void * rng_state,unsigned char * output,size_t len)102 int mbedtls_test_rnd_pseudo_rand(void *rng_state,
103 unsigned char *output,
104 size_t len)
105 {
106 mbedtls_test_rnd_pseudo_info *info =
107 (mbedtls_test_rnd_pseudo_info *) rng_state;
108 uint32_t i, *k, sum, delta = 0x9E3779B9;
109 unsigned char result[4], *out = output;
110
111 if (rng_state == NULL) {
112 return mbedtls_test_rnd_std_rand(NULL, output, len);
113 }
114
115 k = info->key;
116
117 while (len > 0) {
118 size_t use_len = (len > 4) ? 4 : len;
119 sum = 0;
120
121 for (i = 0; i < 32; i++) {
122 info->v0 += (((info->v1 << 4) ^ (info->v1 >> 5))
123 + info->v1) ^ (sum + k[sum & 3]);
124 sum += delta;
125 info->v1 += (((info->v0 << 4) ^ (info->v0 >> 5))
126 + info->v0) ^ (sum + k[(sum>>11) & 3]);
127 }
128
129 MBEDTLS_PUT_UINT32_BE(info->v0, result, 0);
130 memcpy(out, result, use_len);
131 len -= use_len;
132 out += 4;
133 }
134
135 return 0;
136 }
137
