f8e98fc0f57ec2166bf1ad4d892c98a58658b94f
[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 <library.h>
24 #include <utils/debug.h>
25
26 #include <openssl/rand.h>
27 #include <openssl/err.h>
28
29 #include "openssl_rng.h"
30
31 typedef struct private_openssl_rng_t private_openssl_rng_t;
32
33 /**
34 * Private data of openssl_rng_t
35 */
36 struct private_openssl_rng_t {
37
38 /**
39 * Public part of this class.
40 */
41 openssl_rng_t public;
42
43 /**
44 * Quality of randomness
45 */
46 rng_quality_t quality;
47 };
48
49 METHOD(rng_t, get_bytes, bool,
50 private_openssl_rng_t *this, size_t bytes, uint8_t *buffer)
51 {
52 if (this->quality == RNG_WEAK)
53 {
54 /* RAND_pseudo_bytes() returns 1 if returned bytes are strong,
55 * 0 if of not. Both is acceptable for RNG_WEAK. */
56 return RAND_pseudo_bytes((char*)buffer, bytes) != -1;
57 }
58 /* A 0 return value is a failure for RAND_bytes() */
59 return RAND_bytes((char*)buffer, bytes) == 1;
60 }
61
62 METHOD(rng_t, allocate_bytes, bool,
63 private_openssl_rng_t *this, size_t bytes, chunk_t *chunk)
64 {
65 *chunk = chunk_alloc(bytes);
66 if (!get_bytes(this, chunk->len, chunk->ptr))
67 {
68 chunk_free(chunk);
69 return FALSE;
70 }
71 return TRUE;
72 }
73
74 METHOD(rng_t, destroy, void,
75 private_openssl_rng_t *this)
76 {
77 free(this);
78 }
79
80 /*
81 * Described in header.
82 */
83 openssl_rng_t *openssl_rng_create(rng_quality_t quality)
84 {
85 private_openssl_rng_t *this;
86
87 INIT(this,
88 .public = {
89 .rng = {
90 .get_bytes = _get_bytes,
91 .allocate_bytes = _allocate_bytes,
92 .destroy = _destroy,
93 },
94 },
95 .quality = quality,
96 );
97
98 return &this->public;
99 }