eng_rdrand.c revision 296341 
1/* ====================================================================
2 * Copyright (c) 2011 The OpenSSL Project.  All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 *
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 *
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in
13 *    the documentation and/or other materials provided with the
14 *    distribution.
15 *
16 * 3. All advertising materials mentioning features or use of this
17 *    software must display the following acknowledgment:
18 *    "This product includes software developed by the OpenSSL Project
19 *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
20 *
21 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
22 *    endorse or promote products derived from this software without
23 *    prior written permission. For written permission, please contact
24 *    licensing@OpenSSL.org.
25 *
26 * 5. Products derived from this software may not be called "OpenSSL"
27 *    nor may "OpenSSL" appear in their names without prior written
28 *    permission of the OpenSSL Project.
29 *
30 * 6. Redistributions of any form whatsoever must retain the following
31 *    acknowledgment:
32 *    "This product includes software developed by the OpenSSL Project
33 *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
34 *
35 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
36 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
37 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
38 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
39 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
40 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
41 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
42 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
43 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
44 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
45 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
46 * OF THE POSSIBILITY OF SUCH DAMAGE.
47 * ====================================================================
48 */
49
50#include <openssl/opensslconf.h>
51
52#include <stdio.h>
53#include <string.h>
54#include <openssl/engine.h>
55#include <openssl/rand.h>
56#include <openssl/err.h>
57
58#if (defined(__i386)   || defined(__i386__)   || defined(_M_IX86) || \
59     defined(__x86_64) || defined(__x86_64__) || \
60     defined(_M_AMD64) || defined (_M_X64)) && defined(OPENSSL_CPUID_OBJ)
61
62size_t OPENSSL_ia32_rdrand(void);
63
64static int get_random_bytes(unsigned char *buf, int num)
65{
66    size_t rnd;
67
68    while (num >= (int)sizeof(size_t)) {
69        if ((rnd = OPENSSL_ia32_rdrand()) == 0)
70            return 0;
71
72        *((size_t *)buf) = rnd;
73        buf += sizeof(size_t);
74        num -= sizeof(size_t);
75    }
76    if (num) {
77        if ((rnd = OPENSSL_ia32_rdrand()) == 0)
78            return 0;
79
80        memcpy(buf, &rnd, num);
81    }
82
83    return 1;
84}
85
86static int random_status(void)
87{
88    return 1;
89}
90
91static RAND_METHOD rdrand_meth = {
92    NULL,                       /* seed */
93    get_random_bytes,
94    NULL,                       /* cleanup */
95    NULL,                       /* add */
96    get_random_bytes,
97    random_status,
98};
99
100static int rdrand_init(ENGINE *e)
101{
102    return 1;
103}
104
105static const char *engine_e_rdrand_id = "rdrand";
106static const char *engine_e_rdrand_name = "Intel RDRAND engine";
107
108static int bind_helper(ENGINE *e)
109{
110    if (!ENGINE_set_id(e, engine_e_rdrand_id) ||
111        !ENGINE_set_name(e, engine_e_rdrand_name) ||
112        !ENGINE_set_flags(e, ENGINE_FLAGS_NO_REGISTER_ALL) ||
113        !ENGINE_set_init_function(e, rdrand_init) ||
114        !ENGINE_set_RAND(e, &rdrand_meth))
115        return 0;
116
117    return 1;
118}
119
120static ENGINE *ENGINE_rdrand(void)
121{
122    ENGINE *ret = ENGINE_new();
123    if (!ret)
124        return NULL;
125    if (!bind_helper(ret)) {
126        ENGINE_free(ret);
127        return NULL;
128    }
129    return ret;
130}
131
132void ENGINE_load_rdrand(void)
133{
134    extern unsigned int OPENSSL_ia32cap_P[];
135
136    if (OPENSSL_ia32cap_P[1] & (1 << (62 - 32))) {
137        ENGINE *toadd = ENGINE_rdrand();
138        if (!toadd)
139            return;
140        ENGINE_add(toadd);
141        ENGINE_free(toadd);
142        ERR_clear_error();
143    }
144}
145#else
146void ENGINE_load_rdrand(void)
147{
148}
149#endif
150