2 * Copyright 2019-2022 The OpenSSL Project Authors. All Rights Reserved.
3 * Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved.
5 * Licensed under the Apache License 2.0 (the "License"). You may not use
6 * this file except in compliance with the License. You can obtain a copy
7 * in the file LICENSE in the source distribution or at
8 * https://www.openssl.org/source/license.html
12 * Implementation of the FIPS 140-2 section 4.9.2 Conditional Tests.
16 #include <openssl/evp.h>
17 #include <openssl/core_dispatch.h>
18 #include <openssl/params.h>
19 #include <openssl/self_test.h>
20 #include "prov/providercommon.h"
21 #include "prov/provider_ctx.h"
22 #include "internal/cryptlib.h"
23 #include "crypto/rand_pool.h"
24 #include "drbg_local.h"
25 #include "prov/seeding.h"
26 #include "crypto/context.h"
28 typedef struct crng_test_global_st {
29 unsigned char crngt_prev[EVP_MAX_MD_SIZE];
35 static int crngt_get_entropy(PROV_CTX *provctx, const EVP_MD *digest,
36 unsigned char *buf, unsigned char *md,
37 unsigned int *md_size)
43 n = ossl_prov_get_entropy(provctx, &p, 0, CRNGT_BUFSIZ, CRNGT_BUFSIZ);
44 if (n == CRNGT_BUFSIZ) {
45 r = EVP_Digest(p, CRNGT_BUFSIZ, md, md_size, digest, NULL);
47 memcpy(buf, p, CRNGT_BUFSIZ);
48 ossl_prov_cleanup_entropy(provctx, p, n);
52 ossl_prov_cleanup_entropy(provctx, p, n);
56 void ossl_rand_crng_ctx_free(void *vcrngt_glob)
58 CRNG_TEST_GLOBAL *crngt_glob = vcrngt_glob;
60 CRYPTO_THREAD_lock_free(crngt_glob->lock);
61 EVP_MD_free(crngt_glob->md);
62 OPENSSL_free(crngt_glob);
65 void *ossl_rand_crng_ctx_new(OSSL_LIB_CTX *ctx)
67 CRNG_TEST_GLOBAL *crngt_glob = OPENSSL_zalloc(sizeof(*crngt_glob));
69 if (crngt_glob == NULL)
72 if ((crngt_glob->md = EVP_MD_fetch(ctx, "SHA256", "")) == NULL) {
73 OPENSSL_free(crngt_glob);
77 if ((crngt_glob->lock = CRYPTO_THREAD_lock_new()) == NULL) {
78 EVP_MD_free(crngt_glob->md);
79 OPENSSL_free(crngt_glob);
86 static int prov_crngt_compare_previous(const unsigned char *prev,
87 const unsigned char *cur,
90 const int res = memcmp(prev, cur, sz) != 0;
93 ossl_set_error_state(OSSL_SELF_TEST_TYPE_CRNG);
97 size_t ossl_crngt_get_entropy(PROV_DRBG *drbg,
99 int entropy, size_t min_len, size_t max_len,
100 int prediction_resistance)
102 unsigned char md[EVP_MAX_MD_SIZE];
103 unsigned char buf[CRNGT_BUFSIZ];
104 unsigned char *ent, *entp, *entbuf;
108 int crng_test_pass = 1;
109 OSSL_LIB_CTX *libctx = ossl_prov_ctx_get0_libctx(drbg->provctx);
110 CRNG_TEST_GLOBAL *crngt_glob
111 = ossl_lib_ctx_get_data(libctx, OSSL_LIB_CTX_RAND_CRNGT_INDEX);
112 OSSL_CALLBACK *stcb = NULL;
113 void *stcbarg = NULL;
114 OSSL_SELF_TEST *st = NULL;
116 if (crngt_glob == NULL)
119 if (!CRYPTO_THREAD_write_lock(crngt_glob->lock))
122 if (!crngt_glob->preloaded) {
123 if (!crngt_get_entropy(drbg->provctx, crngt_glob->md, buf,
124 crngt_glob->crngt_prev, NULL)) {
125 OPENSSL_cleanse(buf, sizeof(buf));
128 crngt_glob->preloaded = 1;
132 * Calculate how many bytes of seed material we require, rounded up
133 * to the nearest byte. If the entropy is of less than full quality,
134 * the amount required should be scaled up appropriately here.
136 bytes_needed = (entropy + 7) / 8;
137 if (bytes_needed < min_len)
138 bytes_needed = min_len;
139 if (bytes_needed > max_len)
141 entp = ent = OPENSSL_secure_malloc(bytes_needed);
145 OSSL_SELF_TEST_get_callback(libctx, &stcb, &stcbarg);
147 st = OSSL_SELF_TEST_new(stcb, stcbarg);
150 OSSL_SELF_TEST_onbegin(st, OSSL_SELF_TEST_TYPE_CRNG,
151 OSSL_SELF_TEST_DESC_RNG);
154 for (t = bytes_needed; t > 0;) {
155 /* Care needs to be taken to avoid overrunning the buffer */
156 s = t >= CRNGT_BUFSIZ ? CRNGT_BUFSIZ : t;
157 entbuf = t >= CRNGT_BUFSIZ ? entp : buf;
158 if (!crngt_get_entropy(drbg->provctx, crngt_glob->md, entbuf, md, &sz))
160 if (t < CRNGT_BUFSIZ)
161 memcpy(entp, buf, t);
162 /* Force a failure here if the callback returns 1 */
163 if (OSSL_SELF_TEST_oncorrupt_byte(st, md))
164 memcpy(md, crngt_glob->crngt_prev, sz);
165 if (!prov_crngt_compare_previous(crngt_glob->crngt_prev, md, sz)) {
169 /* Update for next block */
170 memcpy(crngt_glob->crngt_prev, md, sz);
179 OSSL_SELF_TEST_onend(st, crng_test_pass);
180 OSSL_SELF_TEST_free(st);
181 OPENSSL_secure_clear_free(ent, bytes_needed);
184 CRYPTO_THREAD_unlock(crngt_glob->lock);
188 void ossl_crngt_cleanup_entropy(ossl_unused PROV_DRBG *drbg,
189 unsigned char *out, size_t outlen)
191 OPENSSL_secure_clear_free(out, outlen);