cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
Log | Files | Refs | README | LICENSE | sfeed.txt

chacha-neon-glue.c (6781B)

      1/*
      2 * ARM NEON and scalar accelerated ChaCha and XChaCha stream ciphers,
      3 * including ChaCha20 (RFC7539)
      4 *
      5 * Copyright (C) 2016 - 2017 Linaro, Ltd. <ard.biesheuvel@linaro.org>
      6 *
      7 * This program is free software; you can redistribute it and/or modify
      8 * it under the terms of the GNU General Public License version 2 as
      9 * published by the Free Software Foundation.
     10 *
     11 * Based on:
     12 * ChaCha20 256-bit cipher algorithm, RFC7539, SIMD glue code
     13 *
     14 * Copyright (C) 2015 Martin Willi
     15 *
     16 * This program is free software; you can redistribute it and/or modify
     17 * it under the terms of the GNU General Public License as published by
     18 * the Free Software Foundation; either version 2 of the License, or
     19 * (at your option) any later version.
     20 */
     21
     22#include <crypto/algapi.h>
     23#include <crypto/internal/chacha.h>
     24#include <crypto/internal/simd.h>
     25#include <crypto/internal/skcipher.h>
     26#include <linux/jump_label.h>
     27#include <linux/kernel.h>
     28#include <linux/module.h>
     29
     30#include <asm/hwcap.h>
     31#include <asm/neon.h>
     32#include <asm/simd.h>
     33
     34asmlinkage void chacha_block_xor_neon(u32 *state, u8 *dst, const u8 *src,
     35				      int nrounds);
     36asmlinkage void chacha_4block_xor_neon(u32 *state, u8 *dst, const u8 *src,
     37				       int nrounds, int bytes);
     38asmlinkage void hchacha_block_neon(const u32 *state, u32 *out, int nrounds);
     39
     40static __ro_after_init DEFINE_STATIC_KEY_FALSE(have_neon);
     41
     42static void chacha_doneon(u32 *state, u8 *dst, const u8 *src,
     43			  int bytes, int nrounds)
     44{
     45	while (bytes > 0) {
     46		int l = min(bytes, CHACHA_BLOCK_SIZE * 5);
     47
     48		if (l <= CHACHA_BLOCK_SIZE) {
     49			u8 buf[CHACHA_BLOCK_SIZE];
     50
     51			memcpy(buf, src, l);
     52			chacha_block_xor_neon(state, buf, buf, nrounds);
     53			memcpy(dst, buf, l);
     54			state[12] += 1;
     55			break;
     56		}
     57		chacha_4block_xor_neon(state, dst, src, nrounds, l);
     58		bytes -= l;
     59		src += l;
     60		dst += l;
     61		state[12] += DIV_ROUND_UP(l, CHACHA_BLOCK_SIZE);
     62	}
     63}
     64
     65void hchacha_block_arch(const u32 *state, u32 *stream, int nrounds)
     66{
     67	if (!static_branch_likely(&have_neon) || !crypto_simd_usable()) {
     68		hchacha_block_generic(state, stream, nrounds);
     69	} else {
     70		kernel_neon_begin();
     71		hchacha_block_neon(state, stream, nrounds);
     72		kernel_neon_end();
     73	}
     74}
     75EXPORT_SYMBOL(hchacha_block_arch);
     76
     77void chacha_init_arch(u32 *state, const u32 *key, const u8 *iv)
     78{
     79	chacha_init_generic(state, key, iv);
     80}
     81EXPORT_SYMBOL(chacha_init_arch);
     82
     83void chacha_crypt_arch(u32 *state, u8 *dst, const u8 *src, unsigned int bytes,
     84		       int nrounds)
     85{
     86	if (!static_branch_likely(&have_neon) || bytes <= CHACHA_BLOCK_SIZE ||
     87	    !crypto_simd_usable())
     88		return chacha_crypt_generic(state, dst, src, bytes, nrounds);
     89
     90	do {
     91		unsigned int todo = min_t(unsigned int, bytes, SZ_4K);
     92
     93		kernel_neon_begin();
     94		chacha_doneon(state, dst, src, todo, nrounds);
     95		kernel_neon_end();
     96
     97		bytes -= todo;
     98		src += todo;
     99		dst += todo;
    100	} while (bytes);
    101}
    102EXPORT_SYMBOL(chacha_crypt_arch);
    103
    104static int chacha_neon_stream_xor(struct skcipher_request *req,
    105				  const struct chacha_ctx *ctx, const u8 *iv)
    106{
    107	struct skcipher_walk walk;
    108	u32 state[16];
    109	int err;
    110
    111	err = skcipher_walk_virt(&walk, req, false);
    112
    113	chacha_init_generic(state, ctx->key, iv);
    114
    115	while (walk.nbytes > 0) {
    116		unsigned int nbytes = walk.nbytes;
    117
    118		if (nbytes < walk.total)
    119			nbytes = rounddown(nbytes, walk.stride);
    120
    121		if (!static_branch_likely(&have_neon) ||
    122		    !crypto_simd_usable()) {
    123			chacha_crypt_generic(state, walk.dst.virt.addr,
    124					     walk.src.virt.addr, nbytes,
    125					     ctx->nrounds);
    126		} else {
    127			kernel_neon_begin();
    128			chacha_doneon(state, walk.dst.virt.addr,
    129				      walk.src.virt.addr, nbytes, ctx->nrounds);
    130			kernel_neon_end();
    131		}
    132		err = skcipher_walk_done(&walk, walk.nbytes - nbytes);
    133	}
    134
    135	return err;
    136}
    137
    138static int chacha_neon(struct skcipher_request *req)
    139{
    140	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
    141	struct chacha_ctx *ctx = crypto_skcipher_ctx(tfm);
    142
    143	return chacha_neon_stream_xor(req, ctx, req->iv);
    144}
    145
    146static int xchacha_neon(struct skcipher_request *req)
    147{
    148	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
    149	struct chacha_ctx *ctx = crypto_skcipher_ctx(tfm);
    150	struct chacha_ctx subctx;
    151	u32 state[16];
    152	u8 real_iv[16];
    153
    154	chacha_init_generic(state, ctx->key, req->iv);
    155	hchacha_block_arch(state, subctx.key, ctx->nrounds);
    156	subctx.nrounds = ctx->nrounds;
    157
    158	memcpy(&real_iv[0], req->iv + 24, 8);
    159	memcpy(&real_iv[8], req->iv + 16, 8);
    160	return chacha_neon_stream_xor(req, &subctx, real_iv);
    161}
    162
    163static struct skcipher_alg algs[] = {
    164	{
    165		.base.cra_name		= "chacha20",
    166		.base.cra_driver_name	= "chacha20-neon",
    167		.base.cra_priority	= 300,
    168		.base.cra_blocksize	= 1,
    169		.base.cra_ctxsize	= sizeof(struct chacha_ctx),
    170		.base.cra_module	= THIS_MODULE,
    171
    172		.min_keysize		= CHACHA_KEY_SIZE,
    173		.max_keysize		= CHACHA_KEY_SIZE,
    174		.ivsize			= CHACHA_IV_SIZE,
    175		.chunksize		= CHACHA_BLOCK_SIZE,
    176		.walksize		= 5 * CHACHA_BLOCK_SIZE,
    177		.setkey			= chacha20_setkey,
    178		.encrypt		= chacha_neon,
    179		.decrypt		= chacha_neon,
    180	}, {
    181		.base.cra_name		= "xchacha20",
    182		.base.cra_driver_name	= "xchacha20-neon",
    183		.base.cra_priority	= 300,
    184		.base.cra_blocksize	= 1,
    185		.base.cra_ctxsize	= sizeof(struct chacha_ctx),
    186		.base.cra_module	= THIS_MODULE,
    187
    188		.min_keysize		= CHACHA_KEY_SIZE,
    189		.max_keysize		= CHACHA_KEY_SIZE,
    190		.ivsize			= XCHACHA_IV_SIZE,
    191		.chunksize		= CHACHA_BLOCK_SIZE,
    192		.walksize		= 5 * CHACHA_BLOCK_SIZE,
    193		.setkey			= chacha20_setkey,
    194		.encrypt		= xchacha_neon,
    195		.decrypt		= xchacha_neon,
    196	}, {
    197		.base.cra_name		= "xchacha12",
    198		.base.cra_driver_name	= "xchacha12-neon",
    199		.base.cra_priority	= 300,
    200		.base.cra_blocksize	= 1,
    201		.base.cra_ctxsize	= sizeof(struct chacha_ctx),
    202		.base.cra_module	= THIS_MODULE,
    203
    204		.min_keysize		= CHACHA_KEY_SIZE,
    205		.max_keysize		= CHACHA_KEY_SIZE,
    206		.ivsize			= XCHACHA_IV_SIZE,
    207		.chunksize		= CHACHA_BLOCK_SIZE,
    208		.walksize		= 5 * CHACHA_BLOCK_SIZE,
    209		.setkey			= chacha12_setkey,
    210		.encrypt		= xchacha_neon,
    211		.decrypt		= xchacha_neon,
    212	}
    213};
    214
    215static int __init chacha_simd_mod_init(void)
    216{
    217	if (!cpu_have_named_feature(ASIMD))
    218		return 0;
    219
    220	static_branch_enable(&have_neon);
    221
    222	return IS_REACHABLE(CONFIG_CRYPTO_SKCIPHER) ?
    223		crypto_register_skciphers(algs, ARRAY_SIZE(algs)) : 0;
    224}
    225
    226static void __exit chacha_simd_mod_fini(void)
    227{
    228	if (IS_REACHABLE(CONFIG_CRYPTO_SKCIPHER) && cpu_have_named_feature(ASIMD))
    229		crypto_unregister_skciphers(algs, ARRAY_SIZE(algs));
    230}
    231
    232module_init(chacha_simd_mod_init);
    233module_exit(chacha_simd_mod_fini);
    234
    235MODULE_DESCRIPTION("ChaCha and XChaCha stream ciphers (NEON accelerated)");
    236MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
    237MODULE_LICENSE("GPL v2");
    238MODULE_ALIAS_CRYPTO("chacha20");
    239MODULE_ALIAS_CRYPTO("chacha20-neon");
    240MODULE_ALIAS_CRYPTO("xchacha20");
    241MODULE_ALIAS_CRYPTO("xchacha20-neon");
    242MODULE_ALIAS_CRYPTO("xchacha12");
    243MODULE_ALIAS_CRYPTO("xchacha12-neon");