2 Unix SMB/CIFS implementation.
4 Functions to create reasonable random numbers for crypto use.
6 Copyright (C) Jeremy Allison 2001
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program. If not, see <http://www.gnu.org/licenses/>.
23 #include "lib/util/genrand.h"
25 #include <gnutls/gnutls.h>
26 #include <gnutls/crypto.h>
29 * Details about the GnuTLS CSPRNG:
31 * https://nikmav.blogspot.com/2017/03/improving-by-simplifying-gnutls-prng.html
34 _PUBLIC_ void generate_random_buffer(uint8_t *out, int len)
36 /* Thread and fork safe random number generator for temporary keys. */
37 gnutls_rnd(GNUTLS_RND_RANDOM, out, len);
40 _PUBLIC_ void generate_secret_buffer(uint8_t *out, int len)
42 /* The key generator, will re-seed after a fixed amount of bytes is
43 * generated (typically less than the nonce), and will also re-seed
44 * based on time, i.e., after few hours of operation without reaching
45 * the limit for a re-seed. For its re-seed it mixes mixes data obtained
46 * from the OS random device with the previous key.
48 gnutls_rnd(GNUTLS_RND_KEY, out, len);
51 _PUBLIC_ void generate_nonce_buffer(uint8_t *out, int len)
54 * The nonce generator will reseed after outputting a fixed amount of
55 * bytes (typically few megabytes), or after few hours of operation
56 * without reaching the limit has passed.
58 gnutls_rnd(GNUTLS_RND_NONCE, out, len);