1 /*
2 * Copyright 2019-2024 The OpenSSL Project Authors. All Rights Reserved.
3 *
4 * Licensed under the Apache License 2.0 (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 <openssl/rand.h>
13 #include "crypto/rand_pool.h"
14 #include "crypto/rand.h"
15 #include "internal/cryptlib.h"
16 #include "prov/seeding.h"
17 #include <version.h>
18 #include <taskLib.h>
19
20 #if defined(OPENSSL_RAND_SEED_NONE)
21 /* none means none */
22 # undef OPENSSL_RAND_SEED_OS
23 #endif
24
25 #if defined(OPENSSL_RAND_SEED_OS)
26 # if _WRS_VXWORKS_MAJOR >= 7
27 # define RAND_SEED_VXRANDLIB
28 # else
29 # error "VxWorks <7 only support RAND_SEED_NONE"
30 # endif
31 #endif
32
33 #if defined(RAND_SEED_VXRANDLIB)
34 # include <randomNumGen.h>
35 #endif
36
37 /* Macro to convert two thirty two bit values into a sixty four bit one */
38 #define TWO32TO64(a, b) ((((uint64_t)(a)) << 32) + (b))
39
get_time_stamp(void)40 static uint64_t get_time_stamp(void)
41 {
42 struct timespec ts;
43
44 if (clock_gettime(CLOCK_REALTIME, &ts) == 0)
45 return TWO32TO64(ts.tv_sec, ts.tv_nsec);
46 return time(NULL);
47 }
48
get_timer_bits(void)49 static uint64_t get_timer_bits(void)
50 {
51 uint64_t res = OPENSSL_rdtsc();
52 struct timespec ts;
53
54 if (res != 0)
55 return res;
56
57 if (clock_gettime(CLOCK_MONOTONIC, &ts) == 0)
58 return TWO32TO64(ts.tv_sec, ts.tv_nsec);
59 return time(NULL);
60 }
61
62 /*
63 * empty implementation
64 * vxworks does not need to init/cleanup or keep open the random lib
65 */
ossl_rand_pool_init(void)66 int ossl_rand_pool_init(void)
67 {
68 return 1;
69 }
70
ossl_rand_pool_cleanup(void)71 void ossl_rand_pool_cleanup(void)
72 {
73 }
74
ossl_rand_pool_keep_random_devices_open(int keep)75 void ossl_rand_pool_keep_random_devices_open(int keep)
76 {
77 }
78
ossl_pool_add_nonce_data(RAND_POOL * pool)79 int ossl_pool_add_nonce_data(RAND_POOL *pool)
80 {
81 struct {
82 pid_t pid;
83 CRYPTO_THREAD_ID tid;
84 uint64_t time;
85 } data;
86
87 memset(&data, 0, sizeof(data));
88
89 /*
90 * Add process id, thread id, and a high resolution timestamp to
91 * ensure that the nonce is unique with high probability for
92 * different process instances.
93 */
94 data.pid = getpid();
95 data.tid = CRYPTO_THREAD_get_current_id();
96 data.time = get_time_stamp();
97
98 return ossl_rand_pool_add(pool, (unsigned char *)&data, sizeof(data), 0);
99 }
100
ossl_pool_acquire_entropy(RAND_POOL * pool)101 size_t ossl_pool_acquire_entropy(RAND_POOL *pool)
102 {
103 #if defined(RAND_SEED_VXRANDLIB)
104 /* vxRandLib based entropy method */
105 size_t bytes_needed;
106
107 bytes_needed = ossl_rand_pool_bytes_needed(pool, 1 /*entropy_factor*/);
108 if (bytes_needed > 0) {
109 int retryCount = 0;
110 STATUS result = ERROR;
111 unsigned char *buffer;
112
113 buffer = ossl_rand_pool_add_begin(pool, bytes_needed);
114 while ((result != OK) && (retryCount < 10)) {
115 RANDOM_NUM_GEN_STATUS status = randStatus();
116
117 if ((status == RANDOM_NUM_GEN_ENOUGH_ENTROPY)
118 || (status == RANDOM_NUM_GEN_MAX_ENTROPY)) {
119 result = randBytes(buffer, bytes_needed);
120 if (result == OK)
121 ossl_rand_pool_add_end(pool, bytes_needed, 8 * bytes_needed);
122 /*
123 * no else here: randStatus said ok, if randBytes failed
124 * it will result in another loop or no entropy
125 */
126 } else {
127 /*
128 * give a minimum delay here to allow OS to collect more
129 * entropy. taskDelay duration will depend on the system tick,
130 * this is by design as the sw-random lib uses interrupts
131 * which will at least happen during ticks
132 */
133 taskDelay(5);
134 }
135 retryCount++;
136 }
137 }
138 return ossl_rand_pool_entropy_available(pool);
139 #else
140 /*
141 * SEED_NONE means none, without randlib we dont have entropy and
142 * rely on it being added externally
143 */
144 return ossl_rand_pool_entropy_available(pool);
145 #endif /* defined(RAND_SEED_VXRANDLIB) */
146 }
147
