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("$FreeBSD$");
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#elif defined(_STANDALONE)
36#include "stand.h"
37#else
38#include <stdint.h>
39#include <string.h>
40#include <strings.h>
41#include <errno.h>
42#include <assert.h>
43#include <openssl/evp.h>
44#define	_OpenSSL_
45#endif
46#include <geom/eli/g_eli.h>
47
48void
49g_eli_crypto_hmac_init(struct hmac_ctx *ctx, const char *hkey,
50    size_t hkeylen)
51{
52	u_char k_ipad[128], k_opad[128], key[128];
53	SHA512_CTX lctx;
54	u_int i;
55
56	bzero(key, sizeof(key));
57	if (hkeylen == 0)
58		; /* do nothing */
59	else if (hkeylen <= 128)
60		bcopy(hkey, key, hkeylen);
61	else {
62		/* If key is longer than 128 bytes reset it to key = SHA512(key). */
63		SHA512_Init(&lctx);
64		SHA512_Update(&lctx, hkey, hkeylen);
65		SHA512_Final(key, &lctx);
66	}
67
68	/* XOR key with ipad and opad values. */
69	for (i = 0; i < sizeof(key); i++) {
70		k_ipad[i] = key[i] ^ 0x36;
71		k_opad[i] = key[i] ^ 0x5c;
72	}
73	explicit_bzero(key, sizeof(key));
74	/* Start inner SHA512. */
75	SHA512_Init(&ctx->innerctx);
76	SHA512_Update(&ctx->innerctx, k_ipad, sizeof(k_ipad));
77	explicit_bzero(k_ipad, sizeof(k_ipad));
78	/* Start outer SHA512. */
79	SHA512_Init(&ctx->outerctx);
80	SHA512_Update(&ctx->outerctx, k_opad, sizeof(k_opad));
81	explicit_bzero(k_opad, sizeof(k_opad));
82}
83
84void
85g_eli_crypto_hmac_update(struct hmac_ctx *ctx, const uint8_t *data,
86    size_t datasize)
87{
88
89	SHA512_Update(&ctx->innerctx, data, datasize);
90}
91
92void
93g_eli_crypto_hmac_final(struct hmac_ctx *ctx, uint8_t *md, size_t mdsize)
94{
95	u_char digest[SHA512_MDLEN];
96
97	/* Complete inner hash */
98	SHA512_Final(digest, &ctx->innerctx);
99
100	/* Complete outer hash */
101	SHA512_Update(&ctx->outerctx, digest, sizeof(digest));
102	SHA512_Final(digest, &ctx->outerctx);
103
104	explicit_bzero(ctx, sizeof(*ctx));
105	/* mdsize == 0 means "Give me the whole hash!" */
106	if (mdsize == 0)
107		mdsize = SHA512_MDLEN;
108	bcopy(digest, md, mdsize);
109	explicit_bzero(digest, sizeof(digest));
110}
111
112void
113g_eli_crypto_hmac(const char *hkey, size_t hkeysize, const uint8_t *data,
114    size_t datasize, uint8_t *md, size_t mdsize)
115{
116	struct hmac_ctx ctx;
117
118	g_eli_crypto_hmac_init(&ctx, hkey, hkeysize);
119	g_eli_crypto_hmac_update(&ctx, data, datasize);
120	g_eli_crypto_hmac_final(&ctx, md, mdsize);
121}
122
123/*
124 * Here we generate IV. It is unique for every sector.
125 */
126void
127g_eli_crypto_ivgen(struct g_eli_softc *sc, off_t offset, u_char *iv,
128    size_t size)
129{
130	uint8_t off[8];
131
132	if ((sc->sc_flags & G_ELI_FLAG_NATIVE_BYTE_ORDER) != 0)
133		bcopy(&offset, off, sizeof(off));
134	else
135		le64enc(off, (uint64_t)offset);
136
137	switch (sc->sc_ealgo) {
138	case CRYPTO_AES_XTS:
139		bcopy(off, iv, sizeof(off));
140		bzero(iv + sizeof(off), size - sizeof(off));
141		break;
142	default:
143	    {
144		u_char hash[SHA256_DIGEST_LENGTH];
145		SHA256_CTX ctx;
146
147		/* Copy precalculated SHA256 context for IV-Key. */
148		bcopy(&sc->sc_ivctx, &ctx, sizeof(ctx));
149		SHA256_Update(&ctx, off, sizeof(off));
150		SHA256_Final(hash, &ctx);
151		bcopy(hash, iv, MIN(sizeof(hash), size));
152		break;
153	    }
154	}
155}
156