crypto/rand/prov_seed.c

   1 /*
   2  * Copyright 2020 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 "crypto/rand.h"
  11 #include "crypto/rand_pool.h"
  12 #include <openssl/core_dispatch.h>
  13 #include <openssl/err.h>
  14
  15 size_t ossl_rand_get_entropy(ossl_unused OSSL_CORE_HANDLE *handle,
  16                              unsigned char **pout, int entropy,
  17                              size_t min_len, size_t max_len)
  18 {
  19     size_t ret = 0;
  20     size_t entropy_available;
  21     RAND_POOL *pool;
  22
  23     pool = ossl_rand_pool_new(entropy, 1, min_len, max_len);
  24     if (pool == NULL) {
  25         ERR_raise(ERR_LIB_RAND, ERR_R_MALLOC_FAILURE);
  26         return 0;
  27     }
  28
  29     /* Get entropy by polling system entropy sources. */
  30     entropy_available = ossl_pool_acquire_entropy(pool);
  31
  32     if (entropy_available > 0) {
  33         ret   = ossl_rand_pool_length(pool);
  34         *pout = ossl_rand_pool_detach(pool);
  35     }
  36
  37     ossl_rand_pool_free(pool);
  38     return ret;
  39 }
  40
  41 void ossl_rand_cleanup_entropy(ossl_unused OSSL_CORE_HANDLE *handle,
  42                                unsigned char *buf, size_t len)
  43 {
  44     OPENSSL_secure_clear_free(buf, len);
  45 }
  46
  47 size_t ossl_rand_get_nonce(ossl_unused OSSL_CORE_HANDLE *handle,
  48                            unsigned char **pout, size_t min_len, size_t max_len,
  49                            const void *salt, size_t salt_len)
  50 {
  51     size_t ret = 0;
  52     RAND_POOL *pool;
  53
  54     pool = ossl_rand_pool_new(0, 0, min_len, max_len);
  55     if (pool == NULL) {
  56         ERR_raise(ERR_LIB_RAND, ERR_R_MALLOC_FAILURE);
  57         return 0;
  58     }
  59
  60     if (!ossl_pool_add_nonce_data(pool))
  61         goto err;
  62
  63     if (salt != NULL && !ossl_rand_pool_add(pool, salt, salt_len, 0))
  64         goto err;
  65     ret   = ossl_rand_pool_length(pool);
  66     *pout = ossl_rand_pool_detach(pool);
  67  err:
  68     ossl_rand_pool_free(pool);
  69     return ret;
  70 }
  71
  72 void ossl_rand_cleanup_nonce(ossl_unused OSSL_CORE_HANDLE *handle,
  73                              unsigned char *buf, size_t len)
  74 {
  75     OPENSSL_clear_free(buf, len);
  76 }