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// SPDX-License-Identifier: GPL-2.0-only
/*
* Accelerated GHASH implementation with ARMv8 vmull.p64 instructions.
*
* Copyright (C) 2015 - 2018 Linaro Ltd. <ard.biesheuvel@linaro.org>
*/
#include <asm/hwcap.h>
#include <asm/neon.h>
#include <asm/simd.h>
#include <asm/unaligned.h>
#include <crypto/b128ops.h>
#include <crypto/cryptd.h>
#include <crypto/internal/hash.h>
#include <crypto/internal/simd.h>
#include <crypto/gf128mul.h>
#include <linux/cpufeature.h>
#include <linux/crypto.h>
#include <linux/module.h>
MODULE_DESCRIPTION("GHASH hash function using ARMv8 Crypto Extensions");
MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS_CRYPTO("ghash");
#define GHASH_BLOCK_SIZE 16
#define GHASH_DIGEST_SIZE 16
struct ghash_key {
u64 h[2];
u64 h2[2];
u64 h3[2];
u64 h4[2];
be128 k;
};
struct ghash_desc_ctx {
u64 digest[GHASH_DIGEST_SIZE/sizeof(u64)];
u8 buf[GHASH_BLOCK_SIZE];
u32 count;
};
struct ghash_async_ctx {
struct cryptd_ahash *cryptd_tfm;
};
asmlinkage void pmull_ghash_update_p64(int blocks, u64 dg[], const char *src,
struct ghash_key const *k,
const char *head);
asmlinkage void pmull_ghash_update_p8(int blocks, u64 dg[], const char *src,
struct ghash_key const *k,
const char *head);
static 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 void ghash_do_update(int blocks, u64 dg[], const char *src,
struct ghash_key *key, const char *head)
{
if (likely(crypto_simd_usable())) {
kernel_neon_begin();
pmull_ghash_update(blocks, dg, src, key, head);
kernel_neon_end();
} else {
be128 dst = { cpu_to_be64(dg[1]), cpu_to_be64(dg[0]) };
do {
const u8 *in = src;
if (head) {
in = head;
blocks++;
head = NULL;
} else {
src += GHASH_BLOCK_SIZE;
}
crypto_xor((u8 *)&dst, in, GHASH_BLOCK_SIZE);
gf128mul_lle(&dst, &key->k);
} while (--blocks);
dg[0] = be64_to_cpu(dst.b);
dg[1] = be64_to_cpu(dst.a);
}
}
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;
ghash_do_update(blocks, ctx->digest, src, key,
partial ? ctx->buf : NULL);
src += blocks * GHASH_BLOCK_SIZE;
partial = 0;
}
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);
ghash_do_update(1, ctx->digest, ctx->buf, key, NULL);
}
put_unaligned_be64(ctx->digest[1], dst);
put_unaligned_be64(ctx->digest[0], dst + 8);
*ctx = (struct ghash_desc_ctx){};
return 0;
}
static void ghash_reflect(u64 h[], const be128 *k)
{
u64 carry = be64_to_cpu(k->a) >> 63;
h[0] = (be64_to_cpu(k->b) << 1) | carry;
h[1] = (be64_to_cpu(k->a) << 1) | (be64_to_cpu(k->b) >> 63);
if (carry)
h[1] ^= 0xc200000000000000UL;
}
static int ghash_setkey(struct crypto_shash *tfm,
const u8 *inkey, unsigned int keylen)
{
struct ghash_key *key = crypto_shash_ctx(tfm);
be128 h;
if (keylen != GHASH_BLOCK_SIZE)
return -EINVAL;
/* needed for the fallback */
memcpy(&key->k, inkey, GHASH_BLOCK_SIZE);
ghash_reflect(key->h, &key->k);
h = key->k;
gf128mul_lle(&h, &key->k);
ghash_reflect(key->h2, &h);
gf128mul_lle(&h, &key->k);
ghash_reflect(key->h3, &h);
gf128mul_lle(&h, &key->k);
ghash_reflect(key->h4, &h);
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",
.base.cra_driver_name = "ghash-ce-sync",
.base.cra_priority = 300 - 1,
.base.cra_blocksize = GHASH_BLOCK_SIZE,
.base.cra_ctxsize = sizeof(struct ghash_key),
.base.cra_module = THIS_MODULE,
};
static int ghash_async_init(struct ahash_request *req)
{
struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
struct ahash_request *cryptd_req = ahash_request_ctx(req);
struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
struct crypto_shash *child = cryptd_ahash_child(cryptd_tfm);
desc->tfm = child;
return crypto_shash_init(desc);
}
static int ghash_async_update(struct ahash_request *req)
{
struct ahash_request *cryptd_req = ahash_request_ctx(req);
struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
if (!crypto_simd_usable() ||
(in_atomic() && cryptd_ahash_queued(cryptd_tfm))) {
memcpy(cryptd_req, req, sizeof(*req));
ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base);
return crypto_ahash_update(cryptd_req);
} else {
struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
return shash_ahash_update(req, desc);
}
}
static int ghash_async_final(struct ahash_request *req)
{
struct ahash_request *cryptd_req = ahash_request_ctx(req);
struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
if (!crypto_simd_usable() ||
(in_atomic() && cryptd_ahash_queued(cryptd_tfm))) {
memcpy(cryptd_req, req, sizeof(*req));
ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base);
return crypto_ahash_final(cryptd_req);
} else {
struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
return crypto_shash_final(desc, req->result);
}
}
static int ghash_async_digest(struct ahash_request *req)
{
struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
struct ahash_request *cryptd_req = ahash_request_ctx(req);
struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
if (!crypto_simd_usable() ||
(in_atomic() && cryptd_ahash_queued(cryptd_tfm))) {
memcpy(cryptd_req, req, sizeof(*req));
ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base);
return crypto_ahash_digest(cryptd_req);
} else {
struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
struct crypto_shash *child = cryptd_ahash_child(cryptd_tfm);
desc->tfm = child;
return shash_ahash_digest(req, desc);
}
}
static int ghash_async_import(struct ahash_request *req, const void *in)
{
struct ahash_request *cryptd_req = ahash_request_ctx(req);
struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
desc->tfm = cryptd_ahash_child(ctx->cryptd_tfm);
return crypto_shash_import(desc, in);
}
static int ghash_async_export(struct ahash_request *req, void *out)
{
struct ahash_request *cryptd_req = ahash_request_ctx(req);
struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
return crypto_shash_export(desc, out);
}
static int ghash_async_setkey(struct crypto_ahash *tfm, const u8 *key,
unsigned int keylen)
{
struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
struct crypto_ahash *child = &ctx->cryptd_tfm->base;
crypto_ahash_clear_flags(child, CRYPTO_TFM_REQ_MASK);
crypto_ahash_set_flags(child, crypto_ahash_get_flags(tfm)
& CRYPTO_TFM_REQ_MASK);
return crypto_ahash_setkey(child, key, keylen);
}
static int ghash_async_init_tfm(struct crypto_tfm *tfm)
{
struct cryptd_ahash *cryptd_tfm;
struct ghash_async_ctx *ctx = crypto_tfm_ctx(tfm);
cryptd_tfm = cryptd_alloc_ahash("ghash-ce-sync", 0, 0);
if (IS_ERR(cryptd_tfm))
return PTR_ERR(cryptd_tfm);
ctx->cryptd_tfm = cryptd_tfm;
crypto_ahash_set_reqsize(__crypto_ahash_cast(tfm),
sizeof(struct ahash_request) +
crypto_ahash_reqsize(&cryptd_tfm->base));
return 0;
}
static void ghash_async_exit_tfm(struct crypto_tfm *tfm)
{
struct ghash_async_ctx *ctx = crypto_tfm_ctx(tfm);
cryptd_free_ahash(ctx->cryptd_tfm);
}
static struct ahash_alg ghash_async_alg = {
.init = ghash_async_init,
.update = ghash_async_update,
.final = ghash_async_final,
.setkey = ghash_async_setkey,
.digest = ghash_async_digest,
.import = ghash_async_import,
.export = ghash_async_export,
.halg.digestsize = GHASH_DIGEST_SIZE,
.halg.statesize = sizeof(struct ghash_desc_ctx),
.halg.base = {
.cra_name = "ghash",
.cra_driver_name = "ghash-ce",
.cra_priority = 300,
.cra_flags = CRYPTO_ALG_ASYNC,
.cra_blocksize = GHASH_BLOCK_SIZE,
.cra_ctxsize = sizeof(struct ghash_async_ctx),
.cra_module = THIS_MODULE,
.cra_init = ghash_async_init_tfm,
.cra_exit = ghash_async_exit_tfm,
},
};
static int __init ghash_ce_mod_init(void)
{
int err;
if (!(elf_hwcap & HWCAP_NEON))
return -ENODEV;
if (elf_hwcap2 & HWCAP2_PMULL)
pmull_ghash_update = pmull_ghash_update_p64;
else
pmull_ghash_update = pmull_ghash_update_p8;
err = crypto_register_shash(&ghash_alg);
if (err)
return err;
err = crypto_register_ahash(&ghash_async_alg);
if (err)
goto err_shash;
return 0;
err_shash:
crypto_unregister_shash(&ghash_alg);
return err;
}
static void __exit ghash_ce_mod_exit(void)
{
crypto_unregister_ahash(&ghash_async_alg);
crypto_unregister_shash(&ghash_alg);
}
module_init(ghash_ce_mod_init);
module_exit(ghash_ce_mod_exit);