Ashley Mills / tinydtls_0_4_0

mbed port of tinydtls

prng.h@1:bc8a649bad13, 2013-10-11 (annotated)

Committer:
ashleymills
Date:
Fri Oct 11 08:46:21 2013 +0000
Revision:
1:bc8a649bad13
Parent:
0:04990d454f45 
Cleaned up all the debug stuff I added finding the hash table bug.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
ashleymills 0:04990d454f45 1 /* prng.h -- Pseudo Random Numbers
ashleymills 0:04990d454f45 2 *
ashleymills 0:04990d454f45 3 * Copyright (C) 2010--2012 Olaf Bergmann <bergmann@tzi.org>
ashleymills 0:04990d454f45 4 *
ashleymills 0:04990d454f45 5 * This file is part of the library tinydtls. Please see
ashleymills 0:04990d454f45 6 * README for terms of use.
ashleymills 0:04990d454f45 7 */
ashleymills 0:04990d454f45 8
ashleymills 0:04990d454f45 9 /**
ashleymills 0:04990d454f45 10 * @file prng.h
ashleymills 0:04990d454f45 11 * @brief Pseudo Random Numbers
ashleymills 0:04990d454f45 12 */
ashleymills 0:04990d454f45 13
ashleymills 0:04990d454f45 14 #ifndef _DTLS_PRNG_H_
ashleymills 0:04990d454f45 15 #define _DTLS_PRNG_H_
ashleymills 0:04990d454f45 16
ashleymills 0:04990d454f45 17 #include "config.h"
ashleymills 0:04990d454f45 18
ashleymills 0:04990d454f45 19 /**
ashleymills 0:04990d454f45 20 * @defgroup prng Pseudo Random Numbers
ashleymills 0:04990d454f45 21 * @{
ashleymills 0:04990d454f45 22 */
ashleymills 0:04990d454f45 23
ashleymills 0:04990d454f45 24 #ifndef WITH_CONTIKI
ashleymills 0:04990d454f45 25 #include <stdlib.h>
ashleymills 0:04990d454f45 26
ashleymills 0:04990d454f45 27 /**
ashleymills 0:04990d454f45 28 * Fills \p buf with \p len random bytes. This is the default
ashleymills 0:04990d454f45 29 * implementation for prng(). You might want to change prng() to use
ashleymills 0:04990d454f45 30 * a better PRNG on your specific platform.
ashleymills 0:04990d454f45 31 */
ashleymills 0:04990d454f45 32 static inline int
ashleymills 0:04990d454f45 33 dtls_prng_impl(unsigned char *buf, size_t len) {
ashleymills 0:04990d454f45 34 while (len--)
ashleymills 0:04990d454f45 35 *buf++ = rand() & 0xFF;
ashleymills 0:04990d454f45 36 return 1;
ashleymills 0:04990d454f45 37 }
ashleymills 0:04990d454f45 38 #else /* WITH_CONTIKI */
ashleymills 0:04990d454f45 39 #include <string.h>
ashleymills 0:04990d454f45 40
ashleymills 0:04990d454f45 41 #ifdef HAVE_PRNG
ashleymills 0:04990d454f45 42 extern int contiki_prng_impl(unsigned char *buf, size_t len);
ashleymills 0:04990d454f45 43 #else
ashleymills 0:04990d454f45 44 /**
ashleymills 0:04990d454f45 45 * Fills \p buf with \p len random bytes. This is the default
ashleymills 0:04990d454f45 46 * implementation for prng(). You might want to change prng() to use
ashleymills 0:04990d454f45 47 * a better PRNG on your specific platform.
ashleymills 0:04990d454f45 48 */
ashleymills 0:04990d454f45 49 static inline int
ashleymills 0:04990d454f45 50 contiki_prng_impl(unsigned char *buf, size_t len) {
ashleymills 0:04990d454f45 51 unsigned short v = random_rand();
ashleymills 0:04990d454f45 52 while (len > sizeof(v)) {
ashleymills 0:04990d454f45 53 memcpy(buf, &v, sizeof(v));
ashleymills 0:04990d454f45 54 len -= sizeof(v);
ashleymills 0:04990d454f45 55 buf += sizeof(v);
ashleymills 0:04990d454f45 56 v = random_rand();
ashleymills 0:04990d454f45 57 }
ashleymills 0:04990d454f45 58
ashleymills 0:04990d454f45 59 memcpy(buf, &v, len);
ashleymills 0:04990d454f45 60 return 1;
ashleymills 0:04990d454f45 61 }
ashleymills 0:04990d454f45 62 #endif /* HAVE_PRNG */
ashleymills 0:04990d454f45 63
ashleymills 0:04990d454f45 64 #define prng(Buf,Length) contiki_prng_impl((Buf), (Length))
ashleymills 0:04990d454f45 65 #define prng_init(Value) random_init((unsigned short)(Value))
ashleymills 0:04990d454f45 66 #endif /* WITH_CONTIKI */
ashleymills 0:04990d454f45 67
ashleymills 0:04990d454f45 68 #ifndef prng
ashleymills 0:04990d454f45 69 /**
ashleymills 0:04990d454f45 70 * Fills \p Buf with \p Length bytes of random data.
ashleymills 0:04990d454f45 71 *
ashleymills 0:04990d454f45 72 * @hideinitializer
ashleymills 0:04990d454f45 73 */
ashleymills 0:04990d454f45 74 #define prng(Buf,Length) dtls_prng_impl((Buf), (Length))
ashleymills 0:04990d454f45 75 #endif
ashleymills 0:04990d454f45 76
ashleymills 0:04990d454f45 77 #ifndef prng_init
ashleymills 0:04990d454f45 78 /**
ashleymills 0:04990d454f45 79 * Called to set the PRNG seed. You may want to re-define this to
ashleymills 0:04990d454f45 80 * allow for a better PRNG.
ashleymills 0:04990d454f45 81 *
ashleymills 0:04990d454f45 82 * @hideinitializer
ashleymills 0:04990d454f45 83 */
ashleymills 0:04990d454f45 84 #define prng_init(Value) srand((unsigned long)(Value))
ashleymills 0:04990d454f45 85 #endif
ashleymills 0:04990d454f45 86
ashleymills 0:04990d454f45 87 /** @} */
ashleymills 0:04990d454f45 88
ashleymills 0:04990d454f45 89 #endif /* _DTLS_PRNG_H_ */