RAND_bytes/RAND_pseudo_bytes returns -1 if it is not supported by RAND method
[strongswan.git] / src / libstrongswan / plugins / openssl / openssl_rng.c
1 /*
2 * Copyright (C) 2012 Aleksandr Grinberg
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a copy
5 * of this software and associated documentation files (the "Software"), to deal
6 * in the Software without restriction, including without limitation the rights
7 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
8 * copies of the Software, and to permit persons to whom the Software is
9 * furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice shall be included in
12 * all copies or substantial portions of the Software.
13 *
14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
17 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
18 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
19 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
20 * THE SOFTWARE.
21 */
22
23 #include <utils/debug.h>
24 #include <openssl/rand.h>
25 #include <openssl/err.h>
26
27 #include "openssl_rng.h"
28
29 typedef struct private_openssl_rng_t private_openssl_rng_t;
30
31 /**
32 * Private data of openssl_rng_t
33 */
34 struct private_openssl_rng_t {
35
36 /**
37 * Public part of this class.
38 */
39 openssl_rng_t public;
40
41 /**
42 * Quality of randomness
43 */
44 rng_quality_t quality;
45 };
46
47 METHOD(rng_t, get_bytes, bool,
48 private_openssl_rng_t *this, size_t bytes, u_int8_t *buffer)
49 {
50 u_int32_t ret;
51
52 if (this->quality == RNG_STRONG)
53 {
54 ret = RAND_bytes((char*)buffer, bytes);
55 }
56 else
57 {
58 ret = RAND_pseudo_bytes((char*)buffer, bytes);
59 }
60 return ret == 1;
61 }
62
63 METHOD(rng_t, allocate_bytes, bool,
64 private_openssl_rng_t *this, size_t bytes, chunk_t *chunk)
65 {
66 *chunk = chunk_alloc(bytes);
67 if (!get_bytes(this, chunk->len, chunk->ptr))
68 {
69 chunk_free(chunk);
70 return FALSE;
71 }
72 return TRUE;
73 }
74
75 METHOD(rng_t, destroy, void,
76 private_openssl_rng_t *this)
77 {
78 free(this);
79 }
80
81 /*
82 * Described in header.
83 */
84 openssl_rng_t *openssl_rng_create(rng_quality_t quality)
85 {
86 private_openssl_rng_t *this;
87
88 INIT(this,
89 .public = {
90 .rng = {
91 .get_bytes = _get_bytes,
92 .allocate_bytes = _allocate_bytes,
93 .destroy = _destroy,
94 },
95 },
96 .quality = quality,
97 );
98
99 return &this->public;
100 }