1 /* 2 * prng.h 3 * 4 * pseudorandom source 5 * 6 * David A. McGrew 7 * Cisco Systems, Inc. 8 */ 9 10 #ifndef PRNG_H 11 #define PRNG_H 12 13 #include "rand_source.h" /* for rand_source_func_t definition */ 14 #include "aes.h" /* for aes */ 15 #include "aes_icm.h" /* for aes ctr */ 16 17 #define MAX_PRNG_OUT_LEN 0xffffffffU 18 19 /* 20 * x917_prng is an ANSI X9.17-like AES-based PRNG 21 */ 22 23 typedef struct { 24 v128_t state; /* state data */ 25 aes_expanded_key_t key; /* secret key */ 26 uint32_t octet_count; /* number of octets output since last init */ 27 rand_source_func_t rand; /* random source for re-initialization */ 28 } x917_prng_t; 29 30 err_status_t 31 x917_prng_init(rand_source_func_t random_source); 32 33 err_status_t 34 x917_prng_get_octet_string(uint8_t *dest, uint32_t len); 35 36 37 /* 38 * ctr_prng is an AES-CTR based PRNG 39 */ 40 41 typedef struct { 42 uint32_t octet_count; /* number of octets output since last init */ 43 aes_icm_ctx_t state; /* state data */ 44 rand_source_func_t rand; /* random source for re-initialization */ 45 } ctr_prng_t; 46 47 err_status_t 48 ctr_prng_init(rand_source_func_t random_source); 49 50 err_status_t 51 ctr_prng_get_octet_string(void *dest, uint32_t len); 52 53 54 #endif 55