1/*
2 * Copyright 2011-2018 The OpenSSL Project Authors. All Rights Reserved.
3 *
4 * Licensed under the OpenSSL license (the "License").  You may not use
5 * this file except in compliance with the License.  You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
8 */
9
10#include <openssl/opensslconf.h>
11
12#include <stdio.h>
13#include <string.h>
14#include "crypto/engine.h"
15#include <openssl/rand.h>
16#include <openssl/err.h>
17#include <openssl/crypto.h>
18
19#if (defined(__i386)   || defined(__i386__)   || defined(_M_IX86) || \
20     defined(__x86_64) || defined(__x86_64__) || \
21     defined(_M_AMD64) || defined (_M_X64)) && defined(OPENSSL_CPUID_OBJ)
22
23size_t OPENSSL_ia32_rdrand_bytes(unsigned char *buf, size_t len);
24
25static int get_random_bytes(unsigned char *buf, int num)
26{
27    if (num < 0) {
28        return 0;
29    }
30
31    return (size_t)num == OPENSSL_ia32_rdrand_bytes(buf, (size_t)num);
32}
33
34static int random_status(void)
35{
36    return 1;
37}
38
39static RAND_METHOD rdrand_meth = {
40    NULL,                       /* seed */
41    get_random_bytes,
42    NULL,                       /* cleanup */
43    NULL,                       /* add */
44    get_random_bytes,
45    random_status,
46};
47
48static int rdrand_init(ENGINE *e)
49{
50    return 1;
51}
52
53static const char *engine_e_rdrand_id = "rdrand";
54static const char *engine_e_rdrand_name = "Intel RDRAND engine";
55
56static int bind_helper(ENGINE *e)
57{
58    if (!ENGINE_set_id(e, engine_e_rdrand_id) ||
59        !ENGINE_set_name(e, engine_e_rdrand_name) ||
60        !ENGINE_set_flags(e, ENGINE_FLAGS_NO_REGISTER_ALL) ||
61        !ENGINE_set_init_function(e, rdrand_init) ||
62        !ENGINE_set_RAND(e, &rdrand_meth))
63        return 0;
64
65    return 1;
66}
67
68static ENGINE *ENGINE_rdrand(void)
69{
70    ENGINE *ret = ENGINE_new();
71    if (ret == NULL)
72        return NULL;
73    if (!bind_helper(ret)) {
74        ENGINE_free(ret);
75        return NULL;
76    }
77    return ret;
78}
79
80void engine_load_rdrand_int(void)
81{
82    extern unsigned int OPENSSL_ia32cap_P[];
83
84    if (OPENSSL_ia32cap_P[1] & (1 << (62 - 32))) {
85        ENGINE *toadd = ENGINE_rdrand();
86        if (!toadd)
87            return;
88        ENGINE_add(toadd);
89        ENGINE_free(toadd);
90        ERR_clear_error();
91    }
92}
93#else
94void engine_load_rdrand_int(void)
95{
96}
97#endif
98