include/crypto/rand.h

   1 /*
   2  * Copyright 2016-2018 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 /*
  11  * Licensed under the Apache License 2.0 (the "License");
  12  * you may not use this file except in compliance with the License.
  13  * You may obtain a copy of the License at
  14  * https://www.openssl.org/source/license.html
  15  * or in the file LICENSE in the source distribution.
  16  */
  17
  18 #ifndef HEADER_RAND_INT_H
  19 # define HEADER_RAND_INT_H
  20
  21 # include <openssl/rand.h>
  22
  23 /* forward declaration */
  24 typedef struct rand_pool_st RAND_POOL;
  25
  26 void rand_cleanup_int(void);
  27
  28 /* Hardware-based seeding functions. */
  29 size_t rand_acquire_entropy_from_tsc(RAND_POOL *pool);
  30 size_t rand_acquire_entropy_from_cpu(RAND_POOL *pool);
  31
  32 /* DRBG entropy callbacks. */
  33 size_t rand_drbg_get_entropy(RAND_DRBG *drbg,
  34                              unsigned char **pout,
  35                              int entropy, size_t min_len, size_t max_len,
  36                              int prediction_resistance);
  37 void rand_drbg_cleanup_entropy(RAND_DRBG *drbg,
  38                                unsigned char *out, size_t outlen);
  39 size_t rand_drbg_get_nonce(RAND_DRBG *drbg,
  40                            unsigned char **pout,
  41                            int entropy, size_t min_len, size_t max_len);
  42 void rand_drbg_cleanup_nonce(RAND_DRBG *drbg,
  43                              unsigned char *out, size_t outlen);
  44
  45 size_t rand_drbg_get_additional_data(RAND_POOL *pool, unsigned char **pout);
  46
  47 void rand_drbg_cleanup_additional_data(RAND_POOL *pool, unsigned char *out);
  48
  49 /* CRNG test entropy filter callbacks. */
  50 size_t rand_crngt_get_entropy(RAND_DRBG *drbg,
  51                               unsigned char **pout,
  52                               int entropy, size_t min_len, size_t max_len,
  53                               int prediction_resistance);
  54 void rand_crngt_cleanup_entropy(RAND_DRBG *drbg,
  55                                 unsigned char *out, size_t outlen);
  56
  57 /*
  58  * RAND_POOL functions
  59  */
  60 RAND_POOL *rand_pool_new(int entropy_requested, int secure,
  61                          size_t min_len, size_t max_len);
  62 RAND_POOL *rand_pool_attach(const unsigned char *buffer, size_t len,
  63                             size_t entropy);
  64 void rand_pool_free(RAND_POOL *pool);
  65
  66 const unsigned char *rand_pool_buffer(RAND_POOL *pool);
  67 unsigned char *rand_pool_detach(RAND_POOL *pool);
  68 void rand_pool_reattach(RAND_POOL *pool, unsigned char *buffer);
  69
  70 size_t rand_pool_entropy(RAND_POOL *pool);
  71 size_t rand_pool_length(RAND_POOL *pool);
  72
  73 size_t rand_pool_entropy_available(RAND_POOL *pool);
  74 size_t rand_pool_entropy_needed(RAND_POOL *pool);
  75 /* |entropy_factor| expresses how many bits of data contain 1 bit of entropy */
  76 size_t rand_pool_bytes_needed(RAND_POOL *pool, unsigned int entropy_factor);
  77 size_t rand_pool_bytes_remaining(RAND_POOL *pool);
  78
  79 int rand_pool_add(RAND_POOL *pool,
  80                   const unsigned char *buffer, size_t len, size_t entropy);
  81 unsigned char *rand_pool_add_begin(RAND_POOL *pool, size_t len);
  82 int rand_pool_add_end(RAND_POOL *pool, size_t len, size_t entropy);
  83
  84
  85 /*
  86  * Add random bytes to the pool to acquire requested amount of entropy
  87  *
  88  * This function is platform specific and tries to acquire the requested
  89  * amount of entropy by polling platform specific entropy sources.
  90  *
  91  * If the function succeeds in acquiring at least |entropy_requested| bits
  92  * of entropy, the total entropy count is returned. If it fails, it returns
  93  * an entropy count of 0.
  94  */
  95 size_t rand_pool_acquire_entropy(RAND_POOL *pool);
  96
  97 /*
  98  * Add some application specific nonce data
  99  *
 100  * This function is platform specific and adds some application specific
 101  * data to the nonce used for instantiating the drbg.
 102  *
 103  * This data currently consists of the process and thread id, and a high
 104  * resolution timestamp. The data does not include an atomic counter,
 105  * because that is added by the calling function rand_drbg_get_nonce().
 106  *
 107  * Returns 1 on success and 0 on failure.
 108  */
 109 int rand_pool_add_nonce_data(RAND_POOL *pool);
 110
 111
 112 /*
 113  * Add some platform specific additional data
 114  *
 115  * This function is platform specific and adds some random noise to the
 116  * additional data used for generating random bytes and for reseeding
 117  * the drbg.
 118  *
 119  * Returns 1 on success and 0 on failure.
 120  */
 121 int rand_pool_add_additional_data(RAND_POOL *pool);
 122
 123 /*
 124  * Initialise the random pool reseeding sources.
 125  *
 126  * Returns 1 on success and 0 on failure.
 127  */
 128 int rand_pool_init(void);
 129
 130 /*
 131  * Finalise the random pool reseeding sources.
 132  */
 133 void rand_pool_cleanup(void);
 134
 135 /*
 136  * Control the random pool use of open file descriptors.
 137  */
 138 void rand_pool_keep_random_devices_open(int keep);
 139
 140 /* Equivalent of RAND_priv_bytes() but additionally taking an OPENSSL_CTX */
 141 int rand_priv_bytes_ex(OPENSSL_CTX *ctx, unsigned char *buf, int num);
 142
 143 /* Equivalent of RAND_bytes() but additionally taking an OPENSSL_CTX */
 144 int rand_bytes_ex(OPENSSL_CTX *ctx, unsigned char *buf, int num);
 145
 146 #endif