include/nettle/knuth-lfib.h

0001 /* knuth-lfib.h
0002
0003    The "lagged fibonacci" pseudorandomness generator, described in
0004    Knuth, TAoCP, 3.6
0005
0006    This file is part of GNU Nettle.
0007
0008    GNU Nettle is free software: you can redistribute it and/or
0009    modify it under the terms of either:
0010
0011      * the GNU Lesser General Public License as published by the Free
0012        Software Foundation; either version 3 of the License, or (at your
0013        option) any later version.
0014
0015    or
0016
0017      * the GNU General Public License as published by the Free
0018        Software Foundation; either version 2 of the License, or (at your
0019        option) any later version.
0020
0021    or both in parallel, as here.
0022
0023    GNU Nettle is distributed in the hope that it will be useful,
0024    but WITHOUT ANY WARRANTY; without even the implied warranty of
0025    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
0026    General Public License for more details.
0027
0028    You should have received copies of the GNU General Public License and
0029    the GNU Lesser General Public License along with this program.  If
0030    not, see http://www.gnu.org/licenses/.
0031 */
0032
0033 /* NOTE: This generator is totally inappropriate for cryptographic
0034  * applications. It is useful for generating deterministic but
0035  * random-looking test data, and is used by the Nettle testsuite. */
0036 #ifndef NETTLE_KNUTH_LFIB_H_INCLUDED
0037 #define NETTLE_KNUTH_LFIB_H_INCLUDED
0038
0039 #include "nettle-types.h"
0040
0041 #ifdef __cplusplus
0042 extern "C" {
0043 #endif
0044
0045 /* Namespace mangling */
0046 #define knuth_lfib_init nettle_knuth_lfib_init
0047 #define knuth_lfib_get nettle_knuth_lfib_get
0048 #define knuth_lfib_get_array nettle_knuth_lfib_get_array
0049 #define knuth_lfib_random nettle_knuth_lfib_random
0050
0051 #define _KNUTH_LFIB_KK 100
0052
0053 struct knuth_lfib_ctx
0054 {
0055   uint32_t x[_KNUTH_LFIB_KK];
0056   unsigned index;
0057 };
0058
0059 void
0060 knuth_lfib_init(struct knuth_lfib_ctx *ctx, uint32_t seed);
0061
0062 /* Get's a single number in the range 0 ... 2^30-1 */
0063 uint32_t
0064 knuth_lfib_get(struct knuth_lfib_ctx *ctx);
0065
0066 /* Get an array of numbers */
0067 void
0068 knuth_lfib_get_array(struct knuth_lfib_ctx *ctx,
0069              size_t n, uint32_t *a);
0070
0071 /* Get an array of octets. */
0072 void
0073 knuth_lfib_random(struct knuth_lfib_ctx *ctx,
0074           size_t n, uint8_t *dst);
0075
0076 #ifdef __cplusplus
0077 }
0078 #endif
0079
0080 #endif /* NETTLE_KNUTH_LFIB_H_INCLUDED */