Version 0.5.0 of tinydtls
Dependents: tinydtls_test_cellular tinydtls_test_ethernet tiny-dtls
prng.h
- Committer:
- ashleymills
- Date:
- 2014-02-12
- Revision:
- 1:598a56fe116e
- Parent:
- 0:ff9ebe0cf0e9
File content as of revision 1:598a56fe116e:
/* prng.h -- Pseudo Random Numbers * * Copyright (C) 2010--2012 Olaf Bergmann <bergmann@tzi.org> * * This file is part of the library tinydtls. Please see * README for terms of use. */ /** * @file prng.h * @brief Pseudo Random Numbers */ #ifndef _DTLS_PRNG_H_ #define _DTLS_PRNG_H_ #include "config.h" /** * @defgroup prng Pseudo Random Numbers * @{ */ #ifndef WITH_CONTIKI #include <stdlib.h> /** * Fills \p buf with \p len random bytes. This is the default * implementation for prng(). You might want to change prng() to use * a better PRNG on your specific platform. */ static inline int dtls_prng_impl(unsigned char *buf, size_t len) { while (len--) *buf++ = rand() & 0xFF; return 1; } #else /* WITH_CONTIKI */ #include <string.h> #ifdef HAVE_PRNG extern int contiki_prng_impl(unsigned char *buf, size_t len); #else /** * Fills \p buf with \p len random bytes. This is the default * implementation for prng(). You might want to change prng() to use * a better PRNG on your specific platform. */ static inline int contiki_prng_impl(unsigned char *buf, size_t len) { unsigned short v = random_rand(); while (len > sizeof(v)) { memcpy(buf, &v, sizeof(v)); len -= sizeof(v); buf += sizeof(v); v = random_rand(); } memcpy(buf, &v, len); return 1; } #endif /* HAVE_PRNG */ #define prng(Buf,Length) contiki_prng_impl((Buf), (Length)) #define prng_init(Value) random_init((unsigned short)(Value)) #endif /* WITH_CONTIKI */ #ifndef prng /** * Fills \p Buf with \p Length bytes of random data. * * @hideinitializer */ #define prng(Buf,Length) dtls_prng_impl((Buf), (Length)) #endif #ifndef prng_init /** * Called to set the PRNG seed. You may want to re-define this to * allow for a better PRNG. * * @hideinitializer */ #define prng_init(Value) srand((unsigned long)(Value)) #endif /** @} */ #endif /* _DTLS_PRNG_H_ */