freebsd-skq/sys/geom/eli/g_eli_hmac.c

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/*-
* Copyright (c) 2005-2010 Pawel Jakub Dawidek <pjd@FreeBSD.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#ifdef _KERNEL
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#elif defined(_STANDALONE)
#include "stand.h"
#else
#include <stdint.h>
#include <string.h>
#include <strings.h>
#include <errno.h>
#include <assert.h>
#include <openssl/evp.h>
#define _OpenSSL_
#endif
#include <geom/eli/g_eli.h>
void
g_eli_crypto_hmac_init(struct hmac_ctx *ctx, const uint8_t *hkey,
size_t hkeylen)
{
u_char k_ipad[128], k_opad[128], key[128];
SHA512_CTX lctx;
u_int i;
bzero(key, sizeof(key));
if (hkeylen == 0)
; /* do nothing */
else if (hkeylen <= 128)
bcopy(hkey, key, hkeylen);
else {
/* If key is longer than 128 bytes reset it to key = SHA512(key). */
SHA512_Init(&lctx);
SHA512_Update(&lctx, hkey, hkeylen);
SHA512_Final(key, &lctx);
}
/* XOR key with ipad and opad values. */
for (i = 0; i < sizeof(key); i++) {
k_ipad[i] = key[i] ^ 0x36;
k_opad[i] = key[i] ^ 0x5c;
}
explicit_bzero(key, sizeof(key));
/* Start inner SHA512. */
SHA512_Init(&ctx->innerctx);
SHA512_Update(&ctx->innerctx, k_ipad, sizeof(k_ipad));
explicit_bzero(k_ipad, sizeof(k_ipad));
/* Start outer SHA512. */
SHA512_Init(&ctx->outerctx);
SHA512_Update(&ctx->outerctx, k_opad, sizeof(k_opad));
explicit_bzero(k_opad, sizeof(k_opad));
}
void
g_eli_crypto_hmac_update(struct hmac_ctx *ctx, const uint8_t *data,
size_t datasize)
{
SHA512_Update(&ctx->innerctx, data, datasize);
}
void
g_eli_crypto_hmac_final(struct hmac_ctx *ctx, uint8_t *md, size_t mdsize)
{
u_char digest[SHA512_MDLEN];
/* Complete inner hash */
SHA512_Final(digest, &ctx->innerctx);
/* Complete outer hash */
SHA512_Update(&ctx->outerctx, digest, sizeof(digest));
SHA512_Final(digest, &ctx->outerctx);
explicit_bzero(ctx, sizeof(*ctx));
/* mdsize == 0 means "Give me the whole hash!" */
if (mdsize == 0)
mdsize = SHA512_MDLEN;
bcopy(digest, md, mdsize);
explicit_bzero(digest, sizeof(digest));
}
void
g_eli_crypto_hmac(const uint8_t *hkey, size_t hkeysize, const uint8_t *data,
size_t datasize, uint8_t *md, size_t mdsize)
{
struct hmac_ctx ctx;
g_eli_crypto_hmac_init(&ctx, hkey, hkeysize);
g_eli_crypto_hmac_update(&ctx, data, datasize);
g_eli_crypto_hmac_final(&ctx, md, mdsize);
}
/*
* Here we generate IV. It is unique for every sector.
*/
void
g_eli_crypto_ivgen(struct g_eli_softc *sc, off_t offset, u_char *iv,
size_t size)
{
uint8_t off[8];
if ((sc->sc_flags & G_ELI_FLAG_NATIVE_BYTE_ORDER) != 0)
bcopy(&offset, off, sizeof(off));
else
le64enc(off, (uint64_t)offset);
switch (sc->sc_ealgo) {
case CRYPTO_AES_XTS:
bcopy(off, iv, sizeof(off));
bzero(iv + sizeof(off), size - sizeof(off));
break;
default:
{
u_char hash[SHA256_DIGEST_LENGTH];
SHA256_CTX ctx;
/* Copy precalculated SHA256 context for IV-Key. */
bcopy(&sc->sc_ivctx, &ctx, sizeof(ctx));
SHA256_Update(&ctx, off, sizeof(off));
SHA256_Final(hash, &ctx);
bcopy(hash, iv, MIN(sizeof(hash), size));
break;
}
}
}