libcoap 4.3.1
coap_prng.h
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1/*
2 * coap_prng.h -- Pseudo Random Numbers
3 *
4 * Copyright (C) 2010-2020 Olaf Bergmann <bergmann@tzi.org>
5 *
6 * SPDX-License-Identifier: BSD-2-Clause
7 *
8 * This file is part of the CoAP library libcoap. Please see README for terms
9 * of use.
10 */
11
17#ifndef COAP_PRNG_H_
18#define COAP_PRNG_H_
19
27#if defined(WITH_CONTIKI)
28#include <string.h>
29
36contiki_prng_impl(unsigned char *buf, size_t len) {
37 uint16_t v = random_rand();
38 while (len > sizeof(v)) {
39 memcpy(buf, &v, sizeof(v));
40 len -= sizeof(v);
41 buf += sizeof(v);
42 v = random_rand();
43 }
44
45 memcpy(buf, &v, len);
46 return 1;
47}
48
49#define coap_prng(Buf,Length) contiki_prng_impl((Buf), (Length))
50#define coap_prng_init(Value) random_init((uint16_t)(Value))
51
52#elif defined(WITH_LWIP) && defined(LWIP_RAND)
53
55lwip_prng_impl(unsigned char *buf, size_t len) {
56 u32_t v = LWIP_RAND();
57 while (len > sizeof(v)) {
58 memcpy(buf, &v, sizeof(v));
59 len -= sizeof(v);
60 buf += sizeof(v);
61 v = LWIP_RAND();
62 }
63
64 memcpy(buf, &v, len);
65 return 1;
66}
67
68#define coap_prng(Buf,Length) lwip_prng_impl((Buf), (Length))
69#define coap_prng_init(Value) (void)Value
70
71#else
72
78typedef int (*coap_rand_func_t)(void *out, size_t len);
79
87
95void coap_prng_init(unsigned int seed);
96
108int coap_prng(void *buf, size_t len);
109
110#endif /* POSIX */
111
114#endif /* COAP_PRNG_H_ */
int(* coap_rand_func_t)(void *out, size_t len)
Data type for random number generator function.
Definition: coap_prng.h:78
void coap_set_prng(coap_rand_func_t rng)
Replaces the current random number generation function with the default function rng.
Definition: coap_prng.c:89
int coap_prng(void *buf, size_t len)
Fills buf with len random bytes using the default pseudo random number generator.
Definition: coap_prng.c:105
void coap_prng_init(unsigned int seed)
Seeds the default random number generation function with the given seed.
Definition: coap_prng.c:94
#define COAP_STATIC_INLINE
Definition: libcoap.h:45