forked from Minki/linux
317f2f750d
This patch adds support for the AES symmetric encryption algorithm for CPUs that have support for the AES part of the ARM v8 Crypto Extensions. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
156 lines
3.8 KiB
C
156 lines
3.8 KiB
C
/*
|
|
* aes-ce-cipher.c - core AES cipher using ARMv8 Crypto Extensions
|
|
*
|
|
* Copyright (C) 2013 - 2014 Linaro Ltd <ard.biesheuvel@linaro.org>
|
|
*
|
|
* 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 <asm/neon.h>
|
|
#include <crypto/aes.h>
|
|
#include <linux/cpufeature.h>
|
|
#include <linux/crypto.h>
|
|
#include <linux/module.h>
|
|
|
|
MODULE_DESCRIPTION("Synchronous AES cipher using ARMv8 Crypto Extensions");
|
|
MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
|
|
MODULE_LICENSE("GPL v2");
|
|
|
|
struct aes_block {
|
|
u8 b[AES_BLOCK_SIZE];
|
|
};
|
|
|
|
static int num_rounds(struct crypto_aes_ctx *ctx)
|
|
{
|
|
/*
|
|
* # of rounds specified by AES:
|
|
* 128 bit key 10 rounds
|
|
* 192 bit key 12 rounds
|
|
* 256 bit key 14 rounds
|
|
* => n byte key => 6 + (n/4) rounds
|
|
*/
|
|
return 6 + ctx->key_length / 4;
|
|
}
|
|
|
|
static void aes_cipher_encrypt(struct crypto_tfm *tfm, u8 dst[], u8 const src[])
|
|
{
|
|
struct crypto_aes_ctx *ctx = crypto_tfm_ctx(tfm);
|
|
struct aes_block *out = (struct aes_block *)dst;
|
|
struct aes_block const *in = (struct aes_block *)src;
|
|
void *dummy0;
|
|
int dummy1;
|
|
|
|
kernel_neon_begin_partial(4);
|
|
|
|
__asm__(" ld1 {v0.16b}, %[in] ;"
|
|
" ld1 {v1.2d}, [%[key]], #16 ;"
|
|
" cmp %w[rounds], #10 ;"
|
|
" bmi 0f ;"
|
|
" bne 3f ;"
|
|
" mov v3.16b, v1.16b ;"
|
|
" b 2f ;"
|
|
"0: mov v2.16b, v1.16b ;"
|
|
" ld1 {v3.2d}, [%[key]], #16 ;"
|
|
"1: aese v0.16b, v2.16b ;"
|
|
" aesmc v0.16b, v0.16b ;"
|
|
"2: ld1 {v1.2d}, [%[key]], #16 ;"
|
|
" aese v0.16b, v3.16b ;"
|
|
" aesmc v0.16b, v0.16b ;"
|
|
"3: ld1 {v2.2d}, [%[key]], #16 ;"
|
|
" subs %w[rounds], %w[rounds], #3 ;"
|
|
" aese v0.16b, v1.16b ;"
|
|
" aesmc v0.16b, v0.16b ;"
|
|
" ld1 {v3.2d}, [%[key]], #16 ;"
|
|
" bpl 1b ;"
|
|
" aese v0.16b, v2.16b ;"
|
|
" eor v0.16b, v0.16b, v3.16b ;"
|
|
" st1 {v0.16b}, %[out] ;"
|
|
|
|
: [out] "=Q"(*out),
|
|
[key] "=r"(dummy0),
|
|
[rounds] "=r"(dummy1)
|
|
: [in] "Q"(*in),
|
|
"1"(ctx->key_enc),
|
|
"2"(num_rounds(ctx) - 2)
|
|
: "cc");
|
|
|
|
kernel_neon_end();
|
|
}
|
|
|
|
static void aes_cipher_decrypt(struct crypto_tfm *tfm, u8 dst[], u8 const src[])
|
|
{
|
|
struct crypto_aes_ctx *ctx = crypto_tfm_ctx(tfm);
|
|
struct aes_block *out = (struct aes_block *)dst;
|
|
struct aes_block const *in = (struct aes_block *)src;
|
|
void *dummy0;
|
|
int dummy1;
|
|
|
|
kernel_neon_begin_partial(4);
|
|
|
|
__asm__(" ld1 {v0.16b}, %[in] ;"
|
|
" ld1 {v1.2d}, [%[key]], #16 ;"
|
|
" cmp %w[rounds], #10 ;"
|
|
" bmi 0f ;"
|
|
" bne 3f ;"
|
|
" mov v3.16b, v1.16b ;"
|
|
" b 2f ;"
|
|
"0: mov v2.16b, v1.16b ;"
|
|
" ld1 {v3.2d}, [%[key]], #16 ;"
|
|
"1: aesd v0.16b, v2.16b ;"
|
|
" aesimc v0.16b, v0.16b ;"
|
|
"2: ld1 {v1.2d}, [%[key]], #16 ;"
|
|
" aesd v0.16b, v3.16b ;"
|
|
" aesimc v0.16b, v0.16b ;"
|
|
"3: ld1 {v2.2d}, [%[key]], #16 ;"
|
|
" subs %w[rounds], %w[rounds], #3 ;"
|
|
" aesd v0.16b, v1.16b ;"
|
|
" aesimc v0.16b, v0.16b ;"
|
|
" ld1 {v3.2d}, [%[key]], #16 ;"
|
|
" bpl 1b ;"
|
|
" aesd v0.16b, v2.16b ;"
|
|
" eor v0.16b, v0.16b, v3.16b ;"
|
|
" st1 {v0.16b}, %[out] ;"
|
|
|
|
: [out] "=Q"(*out),
|
|
[key] "=r"(dummy0),
|
|
[rounds] "=r"(dummy1)
|
|
: [in] "Q"(*in),
|
|
"1"(ctx->key_dec),
|
|
"2"(num_rounds(ctx) - 2)
|
|
: "cc");
|
|
|
|
kernel_neon_end();
|
|
}
|
|
|
|
static struct crypto_alg aes_alg = {
|
|
.cra_name = "aes",
|
|
.cra_driver_name = "aes-ce",
|
|
.cra_priority = 300,
|
|
.cra_flags = CRYPTO_ALG_TYPE_CIPHER,
|
|
.cra_blocksize = AES_BLOCK_SIZE,
|
|
.cra_ctxsize = sizeof(struct crypto_aes_ctx),
|
|
.cra_module = THIS_MODULE,
|
|
.cra_cipher = {
|
|
.cia_min_keysize = AES_MIN_KEY_SIZE,
|
|
.cia_max_keysize = AES_MAX_KEY_SIZE,
|
|
.cia_setkey = crypto_aes_set_key,
|
|
.cia_encrypt = aes_cipher_encrypt,
|
|
.cia_decrypt = aes_cipher_decrypt
|
|
}
|
|
};
|
|
|
|
static int __init aes_mod_init(void)
|
|
{
|
|
return crypto_register_alg(&aes_alg);
|
|
}
|
|
|
|
static void __exit aes_mod_exit(void)
|
|
{
|
|
crypto_unregister_alg(&aes_alg);
|
|
}
|
|
|
|
module_cpu_feature_match(AES, aes_mod_init);
|
|
module_exit(aes_mod_exit);
|