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
mbedtls_test_rnd_std_rand(void * rng_state,unsigned char * output,size_t len)40 int mbedtls_test_rnd_std_rand( void *rng_state,
41 unsigned char *output,
42 size_t len )
43 {
44 #if !defined(__OpenBSD__) && !defined(__NetBSD__)
45 size_t i;
46
47 if( rng_state != NULL )
48 rng_state = NULL;
49
50 for( i = 0; i < len; ++i )
51 output[i] = rand();
52 #else
53 if( rng_state != NULL )
54 rng_state = NULL;
55
56 arc4random_buf( output, len );
57 #endif /* !OpenBSD && !NetBSD */
58
59 return( 0 );
60 }
61
mbedtls_test_rnd_zero_rand(void * rng_state,unsigned char * output,size_t len)62 int mbedtls_test_rnd_zero_rand( void *rng_state,
63 unsigned char *output,
64 size_t len )
65 {
66 if( rng_state != NULL )
67 rng_state = NULL;
68
69 memset( output, 0, len );
70
71 return( 0 );
72 }
73
mbedtls_test_rnd_buffer_rand(void * rng_state,unsigned char * output,size_t len)74 int mbedtls_test_rnd_buffer_rand( void *rng_state,
75 unsigned char *output,
76 size_t len )
77 {
78 mbedtls_test_rnd_buf_info *info = (mbedtls_test_rnd_buf_info *) rng_state;
79 size_t use_len;
80
81 if( rng_state == NULL )
82 return( mbedtls_test_rnd_std_rand( NULL, output, len ) );
83
84 use_len = len;
85 if( len > info->length )
86 use_len = info->length;
87
88 if( use_len )
89 {
90 memcpy( output, info->buf, use_len );
91 info->buf += use_len;
92 info->length -= use_len;
93 }
94
95 if( len - use_len > 0 )
96 {
97 if( info->fallback_f_rng != NULL )
98 {
99 return( info->fallback_f_rng( info->fallback_p_rng,
100 output + use_len,
101 len - use_len ) );
102 }
103 else
104 return( MBEDTLS_ERR_ENTROPY_SOURCE_FAILED );
105 }
106
107 return( 0 );
108 }
109
mbedtls_test_rnd_pseudo_rand(void * rng_state,unsigned char * output,size_t len)110 int mbedtls_test_rnd_pseudo_rand( void *rng_state,
111 unsigned char *output,
112 size_t len )
113 {
114 mbedtls_test_rnd_pseudo_info *info =
115 (mbedtls_test_rnd_pseudo_info *) rng_state;
116 uint32_t i, *k, sum, delta=0x9E3779B9;
117 unsigned char result[4], *out = output;
118
119 if( rng_state == NULL )
120 return( mbedtls_test_rnd_std_rand( NULL, output, len ) );
121
122 k = info->key;
123
124 while( len > 0 )
125 {
126 size_t use_len = ( len > 4 ) ? 4 : len;
127 sum = 0;
128
129 for( i = 0; i < 32; i++ )
130 {
131 info->v0 += ( ( ( info->v1 << 4 ) ^ ( info->v1 >> 5 ) )
132 + info->v1 ) ^ ( sum + k[sum & 3] );
133 sum += delta;
134 info->v1 += ( ( ( info->v0 << 4 ) ^ ( info->v0 >> 5 ) )
135 + info->v0 ) ^ ( sum + k[( sum>>11 ) & 3] );
136 }
137
138 PUT_UINT32_BE( info->v0, result, 0 );
139 memcpy( out, result, use_len );
140 len -= use_len;
141 out += 4;
142 }
143
144 return( 0 );
145 }
146
