2 * Copyright 2019 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 "internal/rand_int.h"
17 #include "internal/thread_once.h"
20 static RAND_POOL *crngt_pool;
21 static unsigned char *crngt_prev;
23 int (*crngt_get_entropy)(unsigned char *) = &rand_crngt_get_entropy_cb;
25 int rand_crngt_get_entropy_cb(unsigned char *buf)
30 while ((n = rand_pool_acquire_entropy(crngt_pool)) != 0)
31 if (n >= CRNGT_BUFSIZ) {
32 p = rand_pool_detach(crngt_pool);
33 memcpy(buf, p, CRNGT_BUFSIZ);
34 rand_pool_reattach(crngt_pool, p);
40 void rand_crngt_cleanup(void)
42 rand_pool_free(crngt_pool);
43 OPENSSL_secure_free(crngt_prev);
48 int rand_crngt_init(void)
50 if ((crngt_pool = rand_pool_new(0, CRNGT_BUFSIZ, CRNGT_BUFSIZ)) == NULL)
52 if ((crngt_prev = OPENSSL_secure_malloc(CRNGT_BUFSIZ)) != NULL
53 && crngt_get_entropy(crngt_prev))
59 static CRYPTO_ONCE rand_crngt_init_flag = CRYPTO_ONCE_STATIC_INIT;
60 DEFINE_RUN_ONCE_STATIC(do_rand_crngt_init)
62 return OPENSSL_init_crypto(0, NULL)
64 && OPENSSL_atexit(&rand_crngt_cleanup);
67 int rand_crngt_single_init(void)
69 return RUN_ONCE(&rand_crngt_init_flag, do_rand_crngt_init);
72 size_t rand_crngt_get_entropy(RAND_DRBG *drbg,
74 int entropy, size_t min_len, size_t max_len,
75 int prediction_resistance)
77 unsigned char buf[CRNGT_BUFSIZ];
79 size_t q, r = 0, s, t = 0;
82 if (!RUN_ONCE(&rand_crngt_init_flag, do_rand_crngt_init))
85 if ((pool = rand_pool_new(entropy, min_len, max_len)) == NULL)
88 while ((q = rand_pool_bytes_needed(pool, 1)) > 0 && attempts-- > 0) {
89 s = q > sizeof(buf) ? sizeof(buf) : q;
90 if (!crngt_get_entropy(buf)
91 || memcmp(crngt_prev, buf, CRNGT_BUFSIZ) == 0
92 || !rand_pool_add(pool, buf, s, s * 8))
94 memcpy(crngt_prev, buf, CRNGT_BUFSIZ);
99 *pout = rand_pool_detach(pool);
101 rand_pool_free(pool);
105 void rand_crngt_cleanup_entropy(RAND_DRBG *drbg,
106 unsigned char *out, size_t outlen)
108 OPENSSL_secure_clear_free(out, outlen);