2 * Copyright 2017 The OpenSSL Project Authors. All Rights Reserved.
4 * Licensed under the OpenSSL license (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
10 #ifndef HEADER_DRBG_RAND_H
11 # define HEADER_DRBG_RAND_H
13 /* In CTR mode, use derivation function ctr_df */
14 #define RAND_DRBG_FLAG_CTR_USE_DF 0x2
17 * Default security strength (in the sense of [NIST SP 800-90Ar1])
18 * of the default OpenSSL DRBG, and the corresponding NID.
20 * Currently supported values: 128, 192, 256
22 * TODO(DRBG): would be nice to have the strength configurable
24 # define RAND_DRBG_STRENGTH 128
25 # define RAND_DRBG_NID NID_aes_128_ctr
28 * Object lifetime functions.
30 RAND_DRBG *RAND_DRBG_new(int type, unsigned int flags, RAND_DRBG *parent);
31 int RAND_DRBG_set(RAND_DRBG *drbg, int type, unsigned int flags);
32 int RAND_DRBG_instantiate(RAND_DRBG *drbg,
33 const unsigned char *pers, size_t perslen);
34 int RAND_DRBG_uninstantiate(RAND_DRBG *drbg);
35 void RAND_DRBG_free(RAND_DRBG *drbg);
38 * Object "use" functions.
40 int RAND_DRBG_reseed(RAND_DRBG *drbg,
41 const unsigned char *adin, size_t adinlen);
42 int RAND_DRBG_generate(RAND_DRBG *drbg, unsigned char *out, size_t outlen,
43 int prediction_resistance,
44 const unsigned char *adin, size_t adinlen);
45 int RAND_DRBG_set_reseed_interval(RAND_DRBG *drbg, int interval);
46 RAND_DRBG *RAND_DRBG_get0_global(void);
47 RAND_DRBG *RAND_DRBG_get0_priv_global(void);
52 #define RAND_DRBG_get_ex_new_index(l, p, newf, dupf, freef) \
53 CRYPTO_get_ex_new_index(CRYPTO_EX_INDEX_DRBG, l, p, newf, dupf, freef)
54 int RAND_DRBG_set_ex_data(RAND_DRBG *dctx, int idx, void *arg);
55 void *RAND_DRBG_get_ex_data(const RAND_DRBG *dctx, int idx);
58 * Callback functions. See comments in drbg_lib.c
60 typedef size_t (*RAND_DRBG_get_entropy_fn)(RAND_DRBG *ctx,
62 int entropy, size_t min_len,
64 typedef void (*RAND_DRBG_cleanup_entropy_fn)(RAND_DRBG *ctx,
65 unsigned char *out, size_t outlen);
66 typedef size_t (*RAND_DRBG_get_nonce_fn)(RAND_DRBG *ctx, unsigned char **pout,
67 int entropy, size_t min_len,
69 typedef void (*RAND_DRBG_cleanup_nonce_fn)(RAND_DRBG *ctx,
70 unsigned char *out, size_t outlen);
72 int RAND_DRBG_set_callbacks(RAND_DRBG *dctx,
73 RAND_DRBG_get_entropy_fn get_entropy,
74 RAND_DRBG_cleanup_entropy_fn cleanup_entropy,
75 RAND_DRBG_get_nonce_fn get_nonce,
76 RAND_DRBG_cleanup_nonce_fn cleanup_nonce);
81 RAND_POOL *RAND_POOL_new(int entropy_requested, size_t min_len, size_t max_len);
82 void RAND_POOL_free(RAND_POOL *pool);
84 const unsigned char *RAND_POOL_buffer(RAND_POOL *pool);
85 unsigned char *RAND_POOL_detach(RAND_POOL *pool);
87 size_t RAND_POOL_entropy(RAND_POOL *pool);
88 size_t RAND_POOL_length(RAND_POOL *pool);
90 size_t RAND_POOL_entropy_available(RAND_POOL *pool);
91 size_t RAND_POOL_entropy_needed(RAND_POOL *pool);
92 size_t RAND_POOL_bytes_needed(RAND_POOL *pool, unsigned int entropy_per_byte);
93 size_t RAND_POOL_bytes_remaining(RAND_POOL *pool);
95 size_t RAND_POOL_add(RAND_POOL *pool,
96 const unsigned char *buffer, size_t len, size_t entropy);
97 unsigned char *RAND_POOL_add_begin(RAND_POOL *pool, size_t len);
98 size_t RAND_POOL_add_end(RAND_POOL *pool, size_t len, size_t entropy);
102 * Add random bytes to the pool to acquire requested amount of entropy
104 * This function is platform specific and tries to acquire the requested
105 * amount of entropy by polling platform specific entropy sources.
107 * If the function succeeds in acquiring at least |entropy_requested| bits
108 * of entropy, the total entropy count is returned. If it fails, it returns
109 * an entropy count of 0.
111 size_t RAND_POOL_acquire_entropy(RAND_POOL *pool);