1 /*
2 * Copyright 2020-2023 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 "rand_local.h"
11 #include "crypto/evp.h"
12 #include "crypto/rand.h"
13 #include "crypto/rand_pool.h"
14 #include "internal/core.h"
15 #include <openssl/core_dispatch.h>
16 #include <openssl/err.h>
17
ossl_rand_get_entropy(ossl_unused OSSL_LIB_CTX * ctx,unsigned char ** pout,int entropy,size_t min_len,size_t max_len)18 size_t ossl_rand_get_entropy(ossl_unused OSSL_LIB_CTX *ctx,
19 unsigned char **pout, int entropy,
20 size_t min_len, size_t max_len)
21 {
22 size_t ret = 0;
23 size_t entropy_available;
24 RAND_POOL *pool;
25
26 pool = ossl_rand_pool_new(entropy, 1, min_len, max_len);
27 if (pool == NULL) {
28 ERR_raise(ERR_LIB_RAND, ERR_R_RAND_LIB);
29 return 0;
30 }
31
32 /* Get entropy by polling system entropy sources. */
33 entropy_available = ossl_pool_acquire_entropy(pool);
34
35 if (entropy_available > 0) {
36 ret = ossl_rand_pool_length(pool);
37 *pout = ossl_rand_pool_detach(pool);
38 }
39
40 ossl_rand_pool_free(pool);
41 return ret;
42 }
43
ossl_rand_get_user_entropy(OSSL_LIB_CTX * ctx,unsigned char ** pout,int entropy,size_t min_len,size_t max_len)44 size_t ossl_rand_get_user_entropy(OSSL_LIB_CTX *ctx,
45 unsigned char **pout, int entropy,
46 size_t min_len, size_t max_len)
47 {
48 EVP_RAND_CTX *rng = ossl_rand_get0_seed_noncreating(ctx);
49
50 if (rng != NULL && evp_rand_can_seed(rng))
51 return evp_rand_get_seed(rng, pout, entropy, min_len, max_len,
52 0, NULL, 0);
53 else
54 return ossl_rand_get_entropy(ctx, pout, entropy, min_len, max_len);
55 }
56
ossl_rand_cleanup_entropy(ossl_unused OSSL_LIB_CTX * ctx,unsigned char * buf,size_t len)57 void ossl_rand_cleanup_entropy(ossl_unused OSSL_LIB_CTX *ctx,
58 unsigned char *buf, size_t len)
59 {
60 OPENSSL_secure_clear_free(buf, len);
61 }
62
ossl_rand_cleanup_user_entropy(OSSL_LIB_CTX * ctx,unsigned char * buf,size_t len)63 void ossl_rand_cleanup_user_entropy(OSSL_LIB_CTX *ctx,
64 unsigned char *buf, size_t len)
65 {
66 EVP_RAND_CTX *rng = ossl_rand_get0_seed_noncreating(ctx);
67
68 if (rng != NULL && evp_rand_can_seed(rng))
69 evp_rand_clear_seed(rng, buf, len);
70 else
71 OPENSSL_secure_clear_free(buf, len);
72 }
73
ossl_rand_get_nonce(ossl_unused OSSL_LIB_CTX * ctx,unsigned char ** pout,size_t min_len,ossl_unused size_t max_len,const void * salt,size_t salt_len)74 size_t ossl_rand_get_nonce(ossl_unused OSSL_LIB_CTX *ctx,
75 unsigned char **pout,
76 size_t min_len, ossl_unused size_t max_len,
77 const void *salt, size_t salt_len)
78 {
79 size_t ret = 0;
80 RAND_POOL *pool;
81
82 pool = ossl_rand_pool_new(0, 0, min_len, max_len);
83 if (pool == NULL) {
84 ERR_raise(ERR_LIB_RAND, ERR_R_RAND_LIB);
85 return 0;
86 }
87
88 if (!ossl_pool_add_nonce_data(pool))
89 goto err;
90
91 if (salt != NULL && !ossl_rand_pool_add(pool, salt, salt_len, 0))
92 goto err;
93 ret = ossl_rand_pool_length(pool);
94 *pout = ossl_rand_pool_detach(pool);
95 err:
96 ossl_rand_pool_free(pool);
97 return ret;
98 }
99
ossl_rand_get_user_nonce(OSSL_LIB_CTX * ctx,unsigned char ** pout,size_t min_len,size_t max_len,const void * salt,size_t salt_len)100 size_t ossl_rand_get_user_nonce(OSSL_LIB_CTX *ctx,
101 unsigned char **pout,
102 size_t min_len, size_t max_len,
103 const void *salt, size_t salt_len)
104 {
105 unsigned char *buf;
106 EVP_RAND_CTX *rng = ossl_rand_get0_seed_noncreating(ctx);
107
108 if (rng == NULL)
109 return ossl_rand_get_nonce(ctx, pout, min_len, max_len, salt, salt_len);
110
111 if ((buf = OPENSSL_malloc(min_len)) == NULL)
112 return 0;
113
114 if (!EVP_RAND_generate(rng, buf, min_len, 0, 0, salt, salt_len)) {
115 OPENSSL_free(buf);
116 return 0;
117 }
118 *pout = buf;
119 return min_len;
120 }
121
ossl_rand_cleanup_nonce(ossl_unused OSSL_LIB_CTX * ctx,unsigned char * buf,size_t len)122 void ossl_rand_cleanup_nonce(ossl_unused OSSL_LIB_CTX *ctx,
123 unsigned char *buf, size_t len)
124 {
125 OPENSSL_clear_free(buf, len);
126 }
127
ossl_rand_cleanup_user_nonce(ossl_unused OSSL_LIB_CTX * ctx,unsigned char * buf,size_t len)128 void ossl_rand_cleanup_user_nonce(ossl_unused OSSL_LIB_CTX *ctx,
129 unsigned char *buf, size_t len)
130 {
131 OPENSSL_clear_free(buf, len);
132 }
133
