148 lines
4.0 KiB
C
148 lines
4.0 KiB
C
/*
|
|
* ChaCha20 256-bit cipher algorithm, RFC7539, SIMD glue code
|
|
*
|
|
* Copyright (C) 2015 Martin Willi
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation; either version 2 of the License, or
|
|
* (at your option) any later version.
|
|
*/
|
|
|
|
#include <crypto/algapi.h>
|
|
#include <crypto/chacha20.h>
|
|
#include <crypto/internal/skcipher.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/module.h>
|
|
#include <asm/fpu/api.h>
|
|
#include <asm/simd.h>
|
|
|
|
#define CHACHA20_STATE_ALIGN 16
|
|
|
|
asmlinkage void chacha20_block_xor_ssse3(u32 *state, u8 *dst, const u8 *src);
|
|
asmlinkage void chacha20_4block_xor_ssse3(u32 *state, u8 *dst, const u8 *src);
|
|
#ifdef CONFIG_AS_AVX2
|
|
asmlinkage void chacha20_8block_xor_avx2(u32 *state, u8 *dst, const u8 *src);
|
|
static bool chacha20_use_avx2;
|
|
#endif
|
|
|
|
static void chacha20_dosimd(u32 *state, u8 *dst, const u8 *src,
|
|
unsigned int bytes)
|
|
{
|
|
u8 buf[CHACHA20_BLOCK_SIZE];
|
|
|
|
#ifdef CONFIG_AS_AVX2
|
|
if (chacha20_use_avx2) {
|
|
while (bytes >= CHACHA20_BLOCK_SIZE * 8) {
|
|
chacha20_8block_xor_avx2(state, dst, src);
|
|
bytes -= CHACHA20_BLOCK_SIZE * 8;
|
|
src += CHACHA20_BLOCK_SIZE * 8;
|
|
dst += CHACHA20_BLOCK_SIZE * 8;
|
|
state[12] += 8;
|
|
}
|
|
}
|
|
#endif
|
|
while (bytes >= CHACHA20_BLOCK_SIZE * 4) {
|
|
chacha20_4block_xor_ssse3(state, dst, src);
|
|
bytes -= CHACHA20_BLOCK_SIZE * 4;
|
|
src += CHACHA20_BLOCK_SIZE * 4;
|
|
dst += CHACHA20_BLOCK_SIZE * 4;
|
|
state[12] += 4;
|
|
}
|
|
while (bytes >= CHACHA20_BLOCK_SIZE) {
|
|
chacha20_block_xor_ssse3(state, dst, src);
|
|
bytes -= CHACHA20_BLOCK_SIZE;
|
|
src += CHACHA20_BLOCK_SIZE;
|
|
dst += CHACHA20_BLOCK_SIZE;
|
|
state[12]++;
|
|
}
|
|
if (bytes) {
|
|
memcpy(buf, src, bytes);
|
|
chacha20_block_xor_ssse3(state, buf, buf);
|
|
memcpy(dst, buf, bytes);
|
|
}
|
|
}
|
|
|
|
static int chacha20_simd(struct skcipher_request *req)
|
|
{
|
|
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
|
|
struct chacha20_ctx *ctx = crypto_skcipher_ctx(tfm);
|
|
u32 *state, state_buf[16 + 2] __aligned(8);
|
|
struct skcipher_walk walk;
|
|
int err;
|
|
|
|
BUILD_BUG_ON(CHACHA20_STATE_ALIGN != 16);
|
|
state = PTR_ALIGN(state_buf + 0, CHACHA20_STATE_ALIGN);
|
|
|
|
if (req->cryptlen <= CHACHA20_BLOCK_SIZE || !may_use_simd())
|
|
return crypto_chacha20_crypt(req);
|
|
|
|
err = skcipher_walk_virt(&walk, req, true);
|
|
|
|
crypto_chacha20_init(state, ctx, walk.iv);
|
|
|
|
kernel_fpu_begin();
|
|
|
|
while (walk.nbytes >= CHACHA20_BLOCK_SIZE) {
|
|
chacha20_dosimd(state, walk.dst.virt.addr, walk.src.virt.addr,
|
|
rounddown(walk.nbytes, CHACHA20_BLOCK_SIZE));
|
|
err = skcipher_walk_done(&walk,
|
|
walk.nbytes % CHACHA20_BLOCK_SIZE);
|
|
}
|
|
|
|
if (walk.nbytes) {
|
|
chacha20_dosimd(state, walk.dst.virt.addr, walk.src.virt.addr,
|
|
walk.nbytes);
|
|
err = skcipher_walk_done(&walk, 0);
|
|
}
|
|
|
|
kernel_fpu_end();
|
|
|
|
return err;
|
|
}
|
|
|
|
static struct skcipher_alg alg = {
|
|
.base.cra_name = "chacha20",
|
|
.base.cra_driver_name = "chacha20-simd",
|
|
.base.cra_priority = 300,
|
|
.base.cra_blocksize = 1,
|
|
.base.cra_ctxsize = sizeof(struct chacha20_ctx),
|
|
.base.cra_alignmask = sizeof(u32) - 1,
|
|
.base.cra_module = THIS_MODULE,
|
|
|
|
.min_keysize = CHACHA20_KEY_SIZE,
|
|
.max_keysize = CHACHA20_KEY_SIZE,
|
|
.ivsize = CHACHA20_IV_SIZE,
|
|
.chunksize = CHACHA20_BLOCK_SIZE,
|
|
.setkey = crypto_chacha20_setkey,
|
|
.encrypt = chacha20_simd,
|
|
.decrypt = chacha20_simd,
|
|
};
|
|
|
|
static int __init chacha20_simd_mod_init(void)
|
|
{
|
|
if (!boot_cpu_has(X86_FEATURE_SSSE3))
|
|
return -ENODEV;
|
|
|
|
#ifdef CONFIG_AS_AVX2
|
|
chacha20_use_avx2 = boot_cpu_has(X86_FEATURE_AVX) &&
|
|
boot_cpu_has(X86_FEATURE_AVX2) &&
|
|
cpu_has_xfeatures(XFEATURE_MASK_SSE | XFEATURE_MASK_YMM, NULL);
|
|
#endif
|
|
return crypto_register_skcipher(&alg);
|
|
}
|
|
|
|
static void __exit chacha20_simd_mod_fini(void)
|
|
{
|
|
crypto_unregister_skcipher(&alg);
|
|
}
|
|
|
|
module_init(chacha20_simd_mod_init);
|
|
module_exit(chacha20_simd_mod_fini);
|
|
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_AUTHOR("Martin Willi <martin@strongswan.org>");
|
|
MODULE_DESCRIPTION("chacha20 cipher algorithm, SIMD accelerated");
|
|
MODULE_ALIAS_CRYPTO("chacha20");
|
|
MODULE_ALIAS_CRYPTO("chacha20-simd");
|