1/*-
2 * Copyright (c) 2005-2010 Pawel Jakub Dawidek <pjd@FreeBSD.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27#include <sys/cdefs.h>
28__FBSDID("$FreeBSD: releng/11.0/sys/geom/eli/g_eli_hmac.c 293306 2016-01-07 05:47:34Z allanjude $");
29
30#include <sys/param.h>
31#ifdef _KERNEL
32#include <sys/systm.h>
33#include <sys/kernel.h>
34#include <sys/malloc.h>
35#else
36#include <stdint.h>
37#include <string.h>
38#include <strings.h>
39#include <errno.h>
40#include <assert.h>
41#include <openssl/evp.h>
42#define	_OpenSSL_
43#endif
44#include <geom/eli/g_eli.h>
45
46void
47g_eli_crypto_hmac_init(struct hmac_ctx *ctx, const uint8_t *hkey,
48    size_t hkeylen)
49{
50	u_char k_ipad[128], key[128];
51	SHA512_CTX lctx;
52	u_int i;
53
54	bzero(key, sizeof(key));
55	if (hkeylen == 0)
56		; /* do nothing */
57	else if (hkeylen <= 128)
58		bcopy(hkey, key, hkeylen);
59	else {
60		/* If key is longer than 128 bytes reset it to key = SHA512(key). */
61		SHA512_Init(&lctx);
62		SHA512_Update(&lctx, hkey, hkeylen);
63		SHA512_Final(key, &lctx);
64	}
65
66	/* XOR key with ipad and opad values. */
67	for (i = 0; i < sizeof(key); i++) {
68		k_ipad[i] = key[i] ^ 0x36;
69		ctx->k_opad[i] = key[i] ^ 0x5c;
70	}
71	bzero(key, sizeof(key));
72	/* Perform inner SHA512. */
73	SHA512_Init(&ctx->shactx);
74	SHA512_Update(&ctx->shactx, k_ipad, sizeof(k_ipad));
75	bzero(k_ipad, sizeof(k_ipad));
76}
77
78void
79g_eli_crypto_hmac_update(struct hmac_ctx *ctx, const uint8_t *data,
80    size_t datasize)
81{
82
83	SHA512_Update(&ctx->shactx, data, datasize);
84}
85
86void
87g_eli_crypto_hmac_final(struct hmac_ctx *ctx, uint8_t *md, size_t mdsize)
88{
89	u_char digest[SHA512_MDLEN];
90	SHA512_CTX lctx;
91
92	SHA512_Final(digest, &ctx->shactx);
93	/* Perform outer SHA512. */
94	SHA512_Init(&lctx);
95	SHA512_Update(&lctx, ctx->k_opad, sizeof(ctx->k_opad));
96	bzero(ctx, sizeof(*ctx));
97	SHA512_Update(&lctx, digest, sizeof(digest));
98	SHA512_Final(digest, &lctx);
99	bzero(&lctx, sizeof(lctx));
100	/* mdsize == 0 means "Give me the whole hash!" */
101	if (mdsize == 0)
102		mdsize = SHA512_MDLEN;
103	bcopy(digest, md, mdsize);
104	bzero(digest, sizeof(digest));
105}
106
107void
108g_eli_crypto_hmac(const uint8_t *hkey, size_t hkeysize, const uint8_t *data,
109    size_t datasize, uint8_t *md, size_t mdsize)
110{
111	struct hmac_ctx ctx;
112
113	g_eli_crypto_hmac_init(&ctx, hkey, hkeysize);
114	g_eli_crypto_hmac_update(&ctx, data, datasize);
115	g_eli_crypto_hmac_final(&ctx, md, mdsize);
116}
117
118/*
119 * Here we generate IV. It is unique for every sector.
120 */
121void
122g_eli_crypto_ivgen(struct g_eli_softc *sc, off_t offset, u_char *iv,
123    size_t size)
124{
125	uint8_t off[8];
126
127	if ((sc->sc_flags & G_ELI_FLAG_NATIVE_BYTE_ORDER) != 0)
128		bcopy(&offset, off, sizeof(off));
129	else
130		le64enc(off, (uint64_t)offset);
131
132	switch (sc->sc_ealgo) {
133	case CRYPTO_AES_XTS:
134		bcopy(off, iv, sizeof(off));
135		bzero(iv + sizeof(off), size - sizeof(off));
136		break;
137	default:
138	    {
139		u_char hash[SHA256_DIGEST_LENGTH];
140		SHA256_CTX ctx;
141
142		/* Copy precalculated SHA256 context for IV-Key. */
143		bcopy(&sc->sc_ivctx, &ctx, sizeof(ctx));
144		SHA256_Update(&ctx, off, sizeof(off));
145		SHA256_Final(hash, &ctx);
146		bcopy(hash, iv, MIN(sizeof(hash), size));
147		break;
148	    }
149	}
150}
151