1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
|
/*
* util/random.h - thread safe random generator, which is reasonably secure.
*
* Copyright (c) 2007, NLnet Labs. All rights reserved.
*
* This software is open source.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* Neither the name of the NLNET LABS nor the names of its contributors may
* be used to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef UTIL_RANDOM_H
#define UTIL_RANDOM_H
/**
* \file
* Thread safe random functions. Similar to arc4random() with an explicit
* initialisation routine.
*/
/**
* random state structure.
*/
struct ub_randstate;
/**
* Initialize the system randomness. Obtains entropy from the system
* before a chroot or privilege makes it unavailable.
* You do not have to call this, otherwise ub_initstate does so.
* @param seed: seed value to create state (if no good entropy is found).
*/
void ub_systemseed(unsigned int seed);
/**
* Initialize a random generator state for use
* @param seed: seed value to create state contents.
* (ignored for arc4random).
* @param from: if not NULL, the seed is taken from this random structure.
* can be used to seed random states via a parent-random-state that
* is itself seeded with entropy.
* @return new state or NULL alloc failure.
*/
struct ub_randstate* ub_initstate(unsigned int seed,
struct ub_randstate* from);
/**
* Generate next random number from the state passed along.
* Thread safe, so random numbers are repeatable.
* @param state: must have been initialised with ub_initstate.
* @return: random 31 bit value.
*/
long int ub_random(struct ub_randstate* state);
/**
* Generate random number between 0 and x-1. No modulo bias.
* @param state: must have been initialised with ub_initstate.
* @param x: an upper limit. not (negative or zero). must be smaller than 2**31.
* @return: random value between 0..x-1. Possibly more than one
* random number is picked from the random stream to satisfy this.
*/
long int ub_random_max(struct ub_randstate* state, long int x);
/**
* Delete the random state.
* @param state: to delete.
*/
void ub_randfree(struct ub_randstate* state);
#endif /* UTIL_RANDOM_H */
|
