forked from rrcarlosr/Jetpack
166 lines
3.6 KiB
C
166 lines
3.6 KiB
C
/*
|
|
* GHASH: digest algorithm for GCM (Galois/Counter Mode).
|
|
*
|
|
* Copyright (c) 2007 Nokia Siemens Networks - Mikko Herranen <mh1@iki.fi>
|
|
* Copyright (c) 2009 Intel Corp.
|
|
* Author: Huang Ying <ying.huang@intel.com>
|
|
*
|
|
* The algorithm implementation is copied from gcm.c.
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify it
|
|
* under the terms of the GNU General Public License version 2 as published
|
|
* by the Free Software Foundation.
|
|
*/
|
|
|
|
#include <crypto/algapi.h>
|
|
#include <crypto/gf128mul.h>
|
|
#include <crypto/ghash.h>
|
|
#include <crypto/internal/hash.h>
|
|
#include <linux/crypto.h>
|
|
#include <linux/init.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/module.h>
|
|
|
|
static int ghash_init(struct shash_desc *desc)
|
|
{
|
|
struct ghash_desc_ctx *dctx = shash_desc_ctx(desc);
|
|
|
|
memset(dctx, 0, sizeof(*dctx));
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int ghash_setkey(struct crypto_shash *tfm,
|
|
const u8 *key, unsigned int keylen)
|
|
{
|
|
struct ghash_ctx *ctx = crypto_shash_ctx(tfm);
|
|
|
|
if (keylen != GHASH_BLOCK_SIZE) {
|
|
crypto_shash_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (ctx->gf128)
|
|
gf128mul_free_4k(ctx->gf128);
|
|
ctx->gf128 = gf128mul_init_4k_lle((be128 *)key);
|
|
if (!ctx->gf128)
|
|
return -ENOMEM;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int ghash_update(struct shash_desc *desc,
|
|
const u8 *src, unsigned int srclen)
|
|
{
|
|
struct ghash_desc_ctx *dctx = shash_desc_ctx(desc);
|
|
struct ghash_ctx *ctx = crypto_shash_ctx(desc->tfm);
|
|
u8 *dst = dctx->buffer;
|
|
|
|
if (!ctx->gf128)
|
|
return -ENOKEY;
|
|
|
|
if (dctx->bytes) {
|
|
int n = min(srclen, dctx->bytes);
|
|
u8 *pos = dst + (GHASH_BLOCK_SIZE - dctx->bytes);
|
|
|
|
dctx->bytes -= n;
|
|
srclen -= n;
|
|
|
|
while (n--)
|
|
*pos++ ^= *src++;
|
|
|
|
if (!dctx->bytes)
|
|
gf128mul_4k_lle((be128 *)dst, ctx->gf128);
|
|
}
|
|
|
|
while (srclen >= GHASH_BLOCK_SIZE) {
|
|
crypto_xor(dst, src, GHASH_BLOCK_SIZE);
|
|
gf128mul_4k_lle((be128 *)dst, ctx->gf128);
|
|
src += GHASH_BLOCK_SIZE;
|
|
srclen -= GHASH_BLOCK_SIZE;
|
|
}
|
|
|
|
if (srclen) {
|
|
dctx->bytes = GHASH_BLOCK_SIZE - srclen;
|
|
while (srclen--)
|
|
*dst++ ^= *src++;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void ghash_flush(struct ghash_ctx *ctx, struct ghash_desc_ctx *dctx)
|
|
{
|
|
u8 *dst = dctx->buffer;
|
|
|
|
if (dctx->bytes) {
|
|
u8 *tmp = dst + (GHASH_BLOCK_SIZE - dctx->bytes);
|
|
|
|
while (dctx->bytes--)
|
|
*tmp++ ^= 0;
|
|
|
|
gf128mul_4k_lle((be128 *)dst, ctx->gf128);
|
|
}
|
|
|
|
dctx->bytes = 0;
|
|
}
|
|
|
|
static int ghash_final(struct shash_desc *desc, u8 *dst)
|
|
{
|
|
struct ghash_desc_ctx *dctx = shash_desc_ctx(desc);
|
|
struct ghash_ctx *ctx = crypto_shash_ctx(desc->tfm);
|
|
u8 *buf = dctx->buffer;
|
|
|
|
if (!ctx->gf128)
|
|
return -ENOKEY;
|
|
|
|
ghash_flush(ctx, dctx);
|
|
memcpy(dst, buf, GHASH_BLOCK_SIZE);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void ghash_exit_tfm(struct crypto_tfm *tfm)
|
|
{
|
|
struct ghash_ctx *ctx = crypto_tfm_ctx(tfm);
|
|
if (ctx->gf128)
|
|
gf128mul_free_4k(ctx->gf128);
|
|
}
|
|
|
|
static struct shash_alg ghash_alg = {
|
|
.digestsize = GHASH_DIGEST_SIZE,
|
|
.init = ghash_init,
|
|
.update = ghash_update,
|
|
.final = ghash_final,
|
|
.setkey = ghash_setkey,
|
|
.descsize = sizeof(struct ghash_desc_ctx),
|
|
.base = {
|
|
.cra_name = "ghash",
|
|
.cra_driver_name = "ghash-generic",
|
|
.cra_priority = 100,
|
|
.cra_flags = CRYPTO_ALG_TYPE_SHASH,
|
|
.cra_blocksize = GHASH_BLOCK_SIZE,
|
|
.cra_ctxsize = sizeof(struct ghash_ctx),
|
|
.cra_module = THIS_MODULE,
|
|
.cra_exit = ghash_exit_tfm,
|
|
},
|
|
};
|
|
|
|
static int __init ghash_mod_init(void)
|
|
{
|
|
return crypto_register_shash(&ghash_alg);
|
|
}
|
|
|
|
static void __exit ghash_mod_exit(void)
|
|
{
|
|
crypto_unregister_shash(&ghash_alg);
|
|
}
|
|
|
|
module_init(ghash_mod_init);
|
|
module_exit(ghash_mod_exit);
|
|
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_DESCRIPTION("GHASH Message Digest Algorithm");
|
|
MODULE_ALIAS_CRYPTO("ghash");
|
|
MODULE_ALIAS_CRYPTO("ghash-generic");
|