/*
* Cryptographic API.
*
* Glue code for the SHA1 Secure Hash Algorithm assembler implementation using
* Supplemental SSE3 instructions.
*
* This file is based on sha1_generic.c
*
* Copyright (c) Alan Smithee.
* Copyright (c) Andrew McDonald <andrew@mcdonald.org.uk>
* Copyright (c) Jean-Francois Dive <jef@linuxbe.org>
* Copyright (c) Mathias Krause <minipli@googlemail.com>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the Free
* Software Foundation; either version 2 of the License, or (at your option)
* any later version.
*
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <crypto/internal/hash.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/mm.h>
#include <linux/cryptohash.h>
#include <linux/types.h>
#include <crypto/sha.h>
#include <asm/byteorder.h>
#include <asm/i387.h>
#include <asm/xcr.h>
#include <asm/xsave.h>
asmlinkage void sha1_transform_ssse3(u32 *digest, const char *data,
unsigned int rounds);
#ifdef CONFIG_AS_AVX
asmlinkage void sha1_transform_avx(u32 *digest, const char *data,
unsigned int rounds);
#endif
static asmlinkage void (*sha1_transform_asm)(u32 *, const char *, unsigned int);
static int sha1_ssse3_init(struct shash_desc *desc)
{
struct sha1_state *sctx = shash_desc_ctx(desc);
*sctx = (struct sha1_state){
.state = { SHA1_H0, SHA1_H1, SHA1_H2, SHA1_H3, SHA1_H4 },
};
return 0;
}
static int __sha1_ssse3_update(struct shash_desc *desc, const u8 *data,
unsigned int len, unsigned int partial)
{
struct sha1_state *sctx = shash_desc_ctx(desc);
unsigned int done = 0;
sctx->count += len;
if (partial) {
done = SHA1_BLOCK_SIZE - partial;
memcpy(sctx->buffer + partial, data, done);
sha1_transform_asm(sctx->state, sctx->buffer, 1);
}
if (len - done >= SHA1_BLOCK_SIZE) {
const unsigned int rounds = (len - done) / SHA1_BLOCK_SIZE;
sha1_transform_asm(sctx->state, data + done, rounds);
done += rounds * SHA1_BLOCK_SIZE;
}
memcpy(sctx->buffer, data + done, len - done);
return 0;
}
static int sha1_ssse3_update(struct shash_desc *desc, const u8 *data,
unsigned int len)
{
struct sha1_state *sctx = shash_desc_ctx(desc);
unsigned int partial = sctx->count % SHA1_BLOCK_SIZE;
int res;
/* Handle the fast case right here */
if (partial + len < SHA1_BLOCK_SIZE) {
sctx->count += len;
memcpy(sctx->buffer + partial, data, len);
return 0;
}
if (!irq_fpu_usable()) {
res = crypto_sha1_update(desc, data, len);
} else {
kernel_fpu_begin();
res = __sha1_ssse3_update(desc, data, len, partial);
kernel_fpu_end();
}
return res;
}
/* Add padding and return the message digest. */
static int sha1_ssse3_final(struct shash_desc *desc, u8 *out)
{
struct sha1_state *sctx = shash_desc_ctx(desc);
unsigned int i, index, padlen;
__be32 *dst = (__be32 *)out;
__be64 bits;
static const u8 padding[SHA1_BLOCK_SIZE] = { 0x80, };
bits = cpu_to_be64(sctx->count << 3);
/* Pad out to 56 mod 64 and append length */
index = sctx->count % SHA1_BLOCK_SIZE;
padlen = (index < 56) ? (56 - index) : ((SHA1_BLOCK_SIZE+56) - index);
if (!irq_fpu_usable()) {
crypto_sha1_update(desc, padding, padlen);
crypto_sha1_update(desc, (const u8 *)&bits, sizeof(bits));
} else {
kernel_fpu_begin();
/* We need to fill a whole block for __sha1_ssse3_update() */
if (padlen <= 56) {
sctx->count += padlen;
memcpy(sctx->buffer + index, padding, padlen);
} else {
__sha1_ssse3_update(desc, padding, padlen, index);
}
__sha1_ssse3_update(desc, (const u8 *)&bits, sizeof(bits), 56);
kernel_fpu_end();
}
/* Store state in digest */
for (i = 0; i < 5; i++)
dst[i] = cpu_to_be32(sctx->state[i]);
/* Wipe context */
memset(sctx, 0, sizeof(*sctx));
return 0;
}
static int sha1_ssse3_export(struct shash_desc *desc, void *out)
{
struct sha1_state *sctx = shash_desc_ctx(desc);
memcpy(out, sctx, sizeof(*sctx));
return 0;
}
static int sha1_ssse3_import(struct shash_desc *desc, const void *in)
{
struct sha1_state *sctx = shash_desc_ctx(desc);
memcpy(sctx, in, sizeof(*sctx));
return 0;
}
static struct shash_alg alg = {
.digestsize = SHA1_DIGEST_SIZE,
.init = sha1_ssse3_init,
.update = sha1_ssse3_update,
.final = sha1_ssse3_final,
.export = sha1_ssse3_export,
.import = sha1_ssse3_import,
.descsize = sizeof(struct sha1_state),
.statesize = sizeof(struct sha1_state),
.base = {
.cra_name = "sha1",
.cra_driver_name= "sha1-ssse3",
.cra_priority = 150,
.cra_flags = CRYPTO_ALG_TYPE_SHASH,
.cra_blocksize = SHA1_BLOCK_SIZE,
.cra_module = THIS_MODULE,
}
};
#ifdef CONFIG_AS_AVX
static bool __init avx_usable(void)
{
u64 xcr0;
if (!cpu_has_avx || !cpu_has_osxsave)
return false;
xcr0 = xgetbv(XCR_XFEATURE_ENABLED_MASK);
if ((xcr0 & (XSTATE_SSE | XSTATE_YMM)) != (XSTATE_SSE | XSTATE_YMM)) {
pr_info("AVX detected but unusable.\n");
return false;
}
return true;
}
#endif
static int __init sha1_ssse3_mod_init(void)
{
/* test for SSSE3 first */
if (cpu_has_ssse3)
sha1_transform_asm = sha1_transform_ssse3;
#ifdef CONFIG_AS_AVX
/* allow AVX to override SSSE3, it's a little faster */
if (avx_usable())
sha1_transform_asm = sha1_transform_avx;
#endif
if (sha1_transform_asm) {
pr_info("Using %s optimized SHA-1 implementation\n",
sha1_transform_asm == sha1_transform_ssse3 ? "SSSE3"
: "AVX");
return crypto_register_shash(&alg);
}
pr_info("Neither AVX nor SSSE3 is available/usable.\n");
return -ENODEV;
}
static void __exit sha1_ssse3_mod_fini(void)
{
crypto_unregister_shash(&alg);
}
module_init(sha1_ssse3_mod_init);
module_exit(sha1_ssse3_mod_fini);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("SHA1 Secure Hash Algorithm, Supplemental SSE3 accelerated");
MODULE_ALIAS("sha1");
