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
23typedef 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
30err_status_t
31x917_prng_init(rand_source_func_t random_source);
32
33err_status_t
34x917_prng_get_octet_string(uint8_t *dest, uint32_t len);
35
36
37/*
38 * ctr_prng is an AES-CTR based PRNG
39 */
40
41typedef 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
47err_status_t
48ctr_prng_init(rand_source_func_t random_source);
49
50err_status_t
51ctr_prng_get_octet_string(void *dest, uint32_t len);
52
53
54#endif
55