1/*	$NetBSD: nist_hash_drbg.h,v 1.1 2019/09/02 20:09:29 riastradh Exp $	*/
2
3/*-
4 * Copyright (c) 2019 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Taylor R. Campbell.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32#ifndef	NIST_HASH_DRBG_H
33#define	NIST_HASH_DRBG_H
34
35#include <sys/types.h>
36
37/* Instantiation: SHA-256 */
38
39/* 10.1 DRBG Mechanisms Based on Hash Functions, Table 2, SHA-256 column */
40#define	NIST_SHA256_HASH_DRBG_SEEDLEN		440u
41
42#define	NIST_HASH_DRBG_SEEDLEN		NIST_SHA256_HASH_DRBG_SEEDLEN
43#define	nist_hash_drbg			nist_sha256_hash_drbg
44#define	nist_hash_drbg_destroy		nist_sha256_hash_drbg_destroy
45#define	nist_hash_drbg_generate		nist_sha256_hash_drbg_generate
46#define	nist_hash_drbg_initialize	nist_sha256_hash_drbg_initialize
47#define	nist_hash_drbg_instantiate	nist_sha256_hash_drbg_instantiate
48#define	nist_hash_drbg_reseed		nist_sha256_hash_drbg_reseed
49
50/*
51 * By 10.1 DRBG Mechanisms Based on Hash Functions, Table 2, the limit
52 * is <2^48 requests between reseeds.  We truncate this to fit in
53 * 32-bit signed integer instead for hysterical raisins.
54 */
55#define	NIST_HASH_DRBG_RESEED_INTERVAL	0x7fffffff
56
57/* 10.1 DRBG Mechanisms Based on Hash Functions, Table 2 */
58#define	NIST_HASH_DRBG_MAX_REQUEST	0x80000
59#define	NIST_HASH_DRBG_MAX_REQUEST_BYTES (NIST_HASH_DRBG_MAX_REQUEST/8)
60
61#define	NIST_HASH_DRBG_SEEDLEN_BYTES	(NIST_HASH_DRBG_SEEDLEN/8)
62
63#define	NIST_HASH_DRBG_MIN_SEEDLEN_BYTES				      \
64	MIN(32, NIST_HASH_DRBG_SEEDLEN_BYTES)
65
66/* 10.1.1.1 Hash_DRBG Internal State */
67
68struct nist_hash_drbg {
69	uint8_t		V[NIST_HASH_DRBG_SEEDLEN_BYTES];
70	uint8_t		C[NIST_HASH_DRBG_SEEDLEN_BYTES];
71	unsigned	reseed_counter;
72};
73
74typedef struct nist_hash_drbg	NIST_HASH_DRBG;
75
76int	nist_hash_drbg_initialize(void); /* self-test */
77int	nist_hash_drbg_instantiate(struct nist_hash_drbg *,
78	    const void *, size_t, const void *, size_t, const void *, size_t);
79int	nist_hash_drbg_reseed(struct nist_hash_drbg *,
80	    const void *, size_t, const void *, size_t);
81int	nist_hash_drbg_generate(struct nist_hash_drbg *, void *, size_t,
82	    const void *, size_t);
83int	nist_hash_drbg_destroy(struct nist_hash_drbg *);
84
85#endif	/* NIST_HASH_DRBG_H */
86