1
0
Fork 0
mirror of synced 2025-03-06 20:59:54 +01:00
linux/arch/s390/crypto/chacha-glue.c
Vladis Dronov 349d03ffd5 crypto: s390 - add crypto library interface for ChaCha20
Implement a crypto library interface for the s390-native ChaCha20 cipher
algorithm. This allows us to stop to select CRYPTO_CHACHA20 and instead
select CRYPTO_ARCH_HAVE_LIB_CHACHA. This allows BIG_KEYS=y not to build
a whole ChaCha20 crypto infrastructure as a built-in, but build a smaller
CRYPTO_LIB_CHACHA instead.

Make CRYPTO_CHACHA_S390 config entry to look like similar ones on other
architectures. Remove CRYPTO_ALGAPI select as anyway it is selected by
CRYPTO_SKCIPHER.

Add a new test module and a test script for ChaCha20 cipher and its
interfaces. Here are test results on an idle z15 machine:

Data | Generic crypto TFM |  s390 crypto TFM |    s390 lib
size |      enc      dec  |     enc     dec  |     enc     dec
-----+--------------------+------------------+----------------
512b |   1545ns   1295ns  |   604ns   446ns  |   430ns  407ns
4k   |   9536ns   9463ns  |  2329ns  2174ns  |  2170ns  2154ns
64k  |  149.6us  149.3us  |  34.4us  34.5us  |  33.9us  33.1us
6M   |  23.61ms  23.11ms  |  4223us  4160us  |  3951us  4008us
60M  |  143.9ms  143.9ms  |  33.5ms  33.2ms  |  32.2ms  32.1ms

Signed-off-by: Vladis Dronov <vdronov@redhat.com>
Reviewed-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2022-05-13 17:24:49 +08:00

130 lines
3.4 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* s390 ChaCha stream cipher.
*
* Copyright IBM Corp. 2021
*/
#define KMSG_COMPONENT "chacha_s390"
#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
#include <crypto/internal/chacha.h>
#include <crypto/internal/skcipher.h>
#include <crypto/algapi.h>
#include <linux/cpufeature.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/sizes.h>
#include <asm/fpu/api.h>
#include "chacha-s390.h"
static void chacha20_crypt_s390(u32 *state, u8 *dst, const u8 *src,
unsigned int nbytes, const u32 *key,
u32 *counter)
{
struct kernel_fpu vxstate;
kernel_fpu_begin(&vxstate, KERNEL_VXR);
chacha20_vx(dst, src, nbytes, key, counter);
kernel_fpu_end(&vxstate, KERNEL_VXR);
*counter += round_up(nbytes, CHACHA_BLOCK_SIZE) / CHACHA_BLOCK_SIZE;
}
static int chacha20_s390(struct skcipher_request *req)
{
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
struct chacha_ctx *ctx = crypto_skcipher_ctx(tfm);
u32 state[CHACHA_STATE_WORDS] __aligned(16);
struct skcipher_walk walk;
unsigned int nbytes;
int rc;
rc = skcipher_walk_virt(&walk, req, false);
chacha_init_generic(state, ctx->key, req->iv);
while (walk.nbytes > 0) {
nbytes = walk.nbytes;
if (nbytes < walk.total)
nbytes = round_down(nbytes, walk.stride);
if (nbytes <= CHACHA_BLOCK_SIZE) {
chacha_crypt_generic(state, walk.dst.virt.addr,
walk.src.virt.addr, nbytes,
ctx->nrounds);
} else {
chacha20_crypt_s390(state, walk.dst.virt.addr,
walk.src.virt.addr, nbytes,
&state[4], &state[12]);
}
rc = skcipher_walk_done(&walk, walk.nbytes - nbytes);
}
return rc;
}
void hchacha_block_arch(const u32 *state, u32 *stream, int nrounds)
{
/* TODO: implement hchacha_block_arch() in assembly */
hchacha_block_generic(state, stream, nrounds);
}
EXPORT_SYMBOL(hchacha_block_arch);
void chacha_init_arch(u32 *state, const u32 *key, const u8 *iv)
{
chacha_init_generic(state, key, iv);
}
EXPORT_SYMBOL(chacha_init_arch);
void chacha_crypt_arch(u32 *state, u8 *dst, const u8 *src,
unsigned int bytes, int nrounds)
{
/* s390 chacha20 implementation has 20 rounds hard-coded,
* it cannot handle a block of data or less, but otherwise
* it can handle data of arbitrary size
*/
if (bytes <= CHACHA_BLOCK_SIZE || nrounds != 20)
chacha_crypt_generic(state, dst, src, bytes, nrounds);
else
chacha20_crypt_s390(state, dst, src, bytes,
&state[4], &state[12]);
}
EXPORT_SYMBOL(chacha_crypt_arch);
static struct skcipher_alg chacha_algs[] = {
{
.base.cra_name = "chacha20",
.base.cra_driver_name = "chacha20-s390",
.base.cra_priority = 900,
.base.cra_blocksize = 1,
.base.cra_ctxsize = sizeof(struct chacha_ctx),
.base.cra_module = THIS_MODULE,
.min_keysize = CHACHA_KEY_SIZE,
.max_keysize = CHACHA_KEY_SIZE,
.ivsize = CHACHA_IV_SIZE,
.chunksize = CHACHA_BLOCK_SIZE,
.setkey = chacha20_setkey,
.encrypt = chacha20_s390,
.decrypt = chacha20_s390,
}
};
static int __init chacha_mod_init(void)
{
return IS_REACHABLE(CONFIG_CRYPTO_SKCIPHER) ?
crypto_register_skciphers(chacha_algs, ARRAY_SIZE(chacha_algs)) : 0;
}
static void __exit chacha_mod_fini(void)
{
if (IS_REACHABLE(CONFIG_CRYPTO_SKCIPHER))
crypto_unregister_skciphers(chacha_algs, ARRAY_SIZE(chacha_algs));
}
module_cpu_feature_match(VXRS, chacha_mod_init);
module_exit(chacha_mod_fini);
MODULE_DESCRIPTION("ChaCha20 stream cipher");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS_CRYPTO("chacha20");