Commit fdd23894 authored by Ard Biesheuvel's avatar Ard Biesheuvel

arm64/crypto: GHASH secure hash using ARMv8 Crypto Extensions

This is a port to ARMv8 (Crypto Extensions) of the Intel implementation of the
GHASH Secure Hash (used in the Galois/Counter chaining mode). It relies on the
optional PMULL/PMULL2 instruction (polynomial multiply long, what Intel call
carry-less multiply).
Signed-off-by: default avatarArd Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent 6ba6c74d
......@@ -18,4 +18,10 @@ config CRYPTO_SHA2_ARM64_CE
depends on ARM64 && KERNEL_MODE_NEON
select CRYPTO_HASH
config CRYPTO_GHASH_ARM64_CE
tristate "GHASH (for GCM chaining mode) using ARMv8 Crypto Extensions"
depends on ARM64 && KERNEL_MODE_NEON
select CRYPTO_HASH
endif
......@@ -13,3 +13,6 @@ sha1-ce-y := sha1-ce-glue.o sha1-ce-core.o
obj-$(CONFIG_CRYPTO_SHA2_ARM64_CE) += sha2-ce.o
sha2-ce-y := sha2-ce-glue.o sha2-ce-core.o
obj-$(CONFIG_CRYPTO_GHASH_ARM64_CE) += ghash-ce.o
ghash-ce-y := ghash-ce-glue.o ghash-ce-core.o
/*
* Accelerated GHASH implementation with ARMv8 PMULL instructions.
*
* Copyright (C) 2014 Linaro Ltd. <ard.biesheuvel@linaro.org>
*
* Based on arch/x86/crypto/ghash-pmullni-intel_asm.S
*
* Copyright (c) 2009 Intel Corp.
* Author: Huang Ying <ying.huang@intel.com>
* Vinodh Gopal
* Erdinc Ozturk
* Deniz Karakoyunlu
*
* 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 <linux/linkage.h>
#include <asm/assembler.h>
DATA .req v0
SHASH .req v1
IN1 .req v2
T1 .req v2
T2 .req v3
T3 .req v4
VZR .req v5
.text
.arch armv8-a+crypto
/*
* void pmull_ghash_update(int blocks, u64 dg[], const char *src,
* struct ghash_key const *k, const char *head)
*/
ENTRY(pmull_ghash_update)
ld1 {DATA.16b}, [x1]
ld1 {SHASH.16b}, [x3]
eor VZR.16b, VZR.16b, VZR.16b
/* do the head block first, if supplied */
cbz x4, 0f
ld1 {IN1.2d}, [x4]
b 1f
0: ld1 {IN1.2d}, [x2], #16
sub w0, w0, #1
1: ext IN1.16b, IN1.16b, IN1.16b, #8
CPU_LE( rev64 IN1.16b, IN1.16b )
eor DATA.16b, DATA.16b, IN1.16b
/* multiply DATA by SHASH in GF(2^128) */
ext T2.16b, DATA.16b, DATA.16b, #8
ext T3.16b, SHASH.16b, SHASH.16b, #8
eor T2.16b, T2.16b, DATA.16b
eor T3.16b, T3.16b, SHASH.16b
pmull2 T1.1q, SHASH.2d, DATA.2d // a1 * b1
pmull DATA.1q, SHASH.1d, DATA.1d // a0 * b0
pmull T2.1q, T2.1d, T3.1d // (a1 + a0)(b1 + b0)
eor T2.16b, T2.16b, T1.16b // (a0 * b1) + (a1 * b0)
eor T2.16b, T2.16b, DATA.16b
ext T3.16b, VZR.16b, T2.16b, #8
ext T2.16b, T2.16b, VZR.16b, #8
eor DATA.16b, DATA.16b, T3.16b
eor T1.16b, T1.16b, T2.16b // <T1:DATA> is result of
// carry-less multiplication
/* first phase of the reduction */
shl T3.2d, DATA.2d, #1
eor T3.16b, T3.16b, DATA.16b
shl T3.2d, T3.2d, #5
eor T3.16b, T3.16b, DATA.16b
shl T3.2d, T3.2d, #57
ext T2.16b, VZR.16b, T3.16b, #8
ext T3.16b, T3.16b, VZR.16b, #8
eor DATA.16b, DATA.16b, T2.16b
eor T1.16b, T1.16b, T3.16b
/* second phase of the reduction */
ushr T2.2d, DATA.2d, #5
eor T2.16b, T2.16b, DATA.16b
ushr T2.2d, T2.2d, #1
eor T2.16b, T2.16b, DATA.16b
ushr T2.2d, T2.2d, #1
eor T1.16b, T1.16b, T2.16b
eor DATA.16b, DATA.16b, T1.16b
cbnz w0, 0b
st1 {DATA.16b}, [x1]
ret
ENDPROC(pmull_ghash_update)
/*
* Accelerated GHASH implementation with ARMv8 PMULL instructions.
*
* Copyright (C) 2014 Linaro Ltd. <ard.biesheuvel@linaro.org>
*
* 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 <asm/neon.h>
#include <asm/unaligned.h>
#include <crypto/internal/hash.h>
#include <linux/cpufeature.h>
#include <linux/crypto.h>
#include <linux/module.h>
MODULE_DESCRIPTION("GHASH secure hash using ARMv8 Crypto Extensions");
MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
MODULE_LICENSE("GPL v2");
#define GHASH_BLOCK_SIZE 16
#define GHASH_DIGEST_SIZE 16
struct ghash_key {
u64 a;
u64 b;
};
struct ghash_desc_ctx {
u64 digest[GHASH_DIGEST_SIZE/sizeof(u64)];
u8 buf[GHASH_BLOCK_SIZE];
u32 count;
};
asmlinkage void pmull_ghash_update(int blocks, u64 dg[], const char *src,
struct ghash_key const *k, const char *head);
static int ghash_init(struct shash_desc *desc)
{
struct ghash_desc_ctx *ctx = shash_desc_ctx(desc);
*ctx = (struct ghash_desc_ctx){};
return 0;
}
static int ghash_update(struct shash_desc *desc, const u8 *src,
unsigned int len)
{
struct ghash_desc_ctx *ctx = shash_desc_ctx(desc);
unsigned int partial = ctx->count % GHASH_BLOCK_SIZE;
ctx->count += len;
if ((partial + len) >= GHASH_BLOCK_SIZE) {
struct ghash_key *key = crypto_shash_ctx(desc->tfm);
int blocks;
if (partial) {
int p = GHASH_BLOCK_SIZE - partial;
memcpy(ctx->buf + partial, src, p);
src += p;
len -= p;
}
blocks = len / GHASH_BLOCK_SIZE;
len %= GHASH_BLOCK_SIZE;
kernel_neon_begin_partial(6);
pmull_ghash_update(blocks, ctx->digest, src, key,
partial ? ctx->buf : NULL);
kernel_neon_end();
src += blocks * GHASH_BLOCK_SIZE;
}
if (len)
memcpy(ctx->buf + partial, src, len);
return 0;
}
static int ghash_final(struct shash_desc *desc, u8 *dst)
{
struct ghash_desc_ctx *ctx = shash_desc_ctx(desc);
unsigned int partial = ctx->count % GHASH_BLOCK_SIZE;
if (partial) {
struct ghash_key *key = crypto_shash_ctx(desc->tfm);
memset(ctx->buf + partial, 0, GHASH_BLOCK_SIZE - partial);
kernel_neon_begin_partial(6);
pmull_ghash_update(1, ctx->digest, ctx->buf, key, NULL);
kernel_neon_end();
}
put_unaligned_be64(ctx->digest[1], dst);
put_unaligned_be64(ctx->digest[0], dst + 8);
*ctx = (struct ghash_desc_ctx){};
return 0;
}
static int ghash_setkey(struct crypto_shash *tfm,
const u8 *inkey, unsigned int keylen)
{
struct ghash_key *key = crypto_shash_ctx(tfm);
u64 a, b;
if (keylen != GHASH_BLOCK_SIZE) {
crypto_shash_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
return -EINVAL;
}
/* perform multiplication by 'x' in GF(2^128) */
b = get_unaligned_be64(inkey);
a = get_unaligned_be64(inkey + 8);
key->a = (a << 1) | (b >> 63);
key->b = (b << 1) | (a >> 63);
if (b >> 63)
key->b ^= 0xc200000000000000UL;
return 0;
}
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-ce",
.cra_priority = 200,
.cra_flags = CRYPTO_ALG_TYPE_SHASH,
.cra_blocksize = GHASH_BLOCK_SIZE,
.cra_ctxsize = sizeof(struct ghash_key),
.cra_module = THIS_MODULE,
},
};
static int __init ghash_ce_mod_init(void)
{
return crypto_register_shash(&ghash_alg);
}
static void __exit ghash_ce_mod_exit(void)
{
crypto_unregister_shash(&ghash_alg);
}
module_cpu_feature_match(PMULL, ghash_ce_mod_init);
module_exit(ghash_ce_mod_exit);
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