/*
* Accelerated GHASH implementation with Intel PCLMULQDQ-NI
* instructions. This file contains glue code.
*
* Copyright (c) 2009 Intel Corp.
* Author: Huang Ying <ying.huang@intel.com>
*
* 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/err.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/crypto.h>
#include <crypto/algapi.h>
#include <crypto/cryptd.h>
#include <crypto/gf128mul.h>
#include <crypto/internal/hash.h>
#include <asm/i387.h>
#include <asm/cpu_device_id.h>
#define GHASH_BLOCK_SIZE 16
#define GHASH_DIGEST_SIZE 16
void clmul_ghash_mul(char *dst, const be128 *shash);
void clmul_ghash_update(char *dst, const char *src, unsigned int srclen,
const be128 *shash);
void clmul_ghash_setkey(be128 *shash, const u8 *key);
struct ghash_async_ctx {
struct cryptd_ahash *cryptd_tfm;
};
struct ghash_ctx {
be128 shash;
};
struct ghash_desc_ctx {
u8 buffer[GHASH_BLOCK_SIZE];
u32 bytes;
};
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;
}
clmul_ghash_setkey(&ctx->shash, key);
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;
kernel_fpu_begin();
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)
clmul_ghash_mul(dst, &ctx->shash);
}
clmul_ghash_update(dst, src, srclen, &ctx->shash);
kernel_fpu_end();
if (srclen & 0xf) {
src += srclen - (srclen & 0xf);
srclen &= 0xf;
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;
kernel_fpu_begin();
clmul_ghash_mul(dst, &ctx->shash);
kernel_fpu_end();
}
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;
ghash_flush(ctx, dctx);
memcpy(dst, buf, GHASH_BLOCK_SIZE);
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-pclmulqdqni",
.cra_priority = 0,
.cra_flags = CRYPTO_ALG_TYPE_SHASH,
.cra_blocksize = GHASH_BLOCK_SIZE,
.cra_ctxsize = sizeof(struct ghash_ctx),
.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;
if (!irq_fpu_usable()) {
memcpy(cryptd_req, req, sizeof(*req));
ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base);
return crypto_ahash_init(cryptd_req);
} else {
struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
struct crypto_shash *child = cryptd_ahash_child(cryptd_tfm);
desc->tfm = child;
desc->flags = req->base.flags;
return crypto_shash_init(desc);
}
}
static int ghash_async_update(struct ahash_request *req)
{
struct ahash_request *cryptd_req = ahash_request_ctx(req);
if (!irq_fpu_usable()) {
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;
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);
if (!irq_fpu_usable()) {
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;
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 (!irq_fpu_usable()) {
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;
desc->flags = req->base.flags;
return shash_ahash_digest(req, desc);
}
}
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;
int err;
crypto_ahash_clear_flags(child, CRYPTO_TFM_REQ_MASK);
crypto_ahash_set_flags(child, crypto_ahash_get_flags(tfm)
& CRYPTO_TFM_REQ_MASK);
err = crypto_ahash_setkey(child, key, keylen);
crypto_ahash_set_flags(tfm, crypto_ahash_get_flags(child)
& CRYPTO_TFM_RES_MASK);
return err;
}
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-pclmulqdqni", 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,
.halg = {
.digestsize = GHASH_DIGEST_SIZE,
.base = {
.cra_name = "ghash",
.cra_driver_name = "ghash-clmulni",
.cra_priority = 400,
.cra_flags = CRYPTO_ALG_TYPE_AHASH | CRYPTO_ALG_ASYNC,
.cra_blocksize = GHASH_BLOCK_SIZE,
.cra_type = &crypto_ahash_type,
.cra_module = THIS_MODULE,
.cra_init = ghash_async_init_tfm,
.cra_exit = ghash_async_exit_tfm,
},
},
};
static const struct x86_cpu_id pcmul_cpu_id[] = {
X86_FEATURE_MATCH(X86_FEATURE_PCLMULQDQ), /* Pickle-Mickle-Duck */
{}
};
MODULE_DEVICE_TABLE(x86cpu, pcmul_cpu_id);
static int __init ghash_pclmulqdqni_mod_init(void)
{
int err;
if (!x86_match_cpu(pcmul_cpu_id))
return -ENODEV;
err = crypto_register_shash(&ghash_alg);
if (err)
goto err_out;
err = crypto_register_ahash(&ghash_async_alg);
if (err)
goto err_shash;
return 0;
err_shash:
crypto_unregister_shash(&ghash_alg);
err_out:
return err;
}
static void __exit ghash_pclmulqdqni_mod_exit(void)
{
crypto_unregister_ahash(&ghash_async_alg);
crypto_unregister_shash(&ghash_alg);
}
module_init(ghash_pclmulqdqni_mod_init);
module_exit(ghash_pclmulqdqni_mod_exit);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("GHASH Message Digest Algorithm, "
"acclerated by PCLMULQDQ-NI");
MODULE_ALIAS("ghash");
