mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-12-23 02:54:32 +08:00
e59c1c9874
Take the existing small footprint and mostly time invariant C code and turn it into a AES library that can be used for non-performance critical, casual use of AES, and as a fallback for, e.g., SIMD code that needs a secondary path that can be taken in contexts where the SIMD unit is off limits (e.g., in hard interrupts taken from kernel context) Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
84 lines
2.0 KiB
C
84 lines
2.0 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/*
|
|
* Scalar fixed time AES core transform
|
|
*
|
|
* Copyright (C) 2017 Linaro Ltd <ard.biesheuvel@linaro.org>
|
|
*/
|
|
|
|
#include <crypto/aes.h>
|
|
#include <linux/crypto.h>
|
|
#include <linux/module.h>
|
|
|
|
static int aesti_set_key(struct crypto_tfm *tfm, const u8 *in_key,
|
|
unsigned int key_len)
|
|
{
|
|
struct crypto_aes_ctx *ctx = crypto_tfm_ctx(tfm);
|
|
|
|
return aes_expandkey(ctx, in_key, key_len);
|
|
}
|
|
|
|
static void aesti_encrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
|
|
{
|
|
const struct crypto_aes_ctx *ctx = crypto_tfm_ctx(tfm);
|
|
unsigned long flags;
|
|
|
|
/*
|
|
* Temporarily disable interrupts to avoid races where cachelines are
|
|
* evicted when the CPU is interrupted to do something else.
|
|
*/
|
|
local_irq_save(flags);
|
|
|
|
aes_encrypt(ctx, out, in);
|
|
|
|
local_irq_restore(flags);
|
|
}
|
|
|
|
static void aesti_decrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
|
|
{
|
|
const struct crypto_aes_ctx *ctx = crypto_tfm_ctx(tfm);
|
|
unsigned long flags;
|
|
|
|
/*
|
|
* Temporarily disable interrupts to avoid races where cachelines are
|
|
* evicted when the CPU is interrupted to do something else.
|
|
*/
|
|
local_irq_save(flags);
|
|
|
|
aes_decrypt(ctx, out, in);
|
|
|
|
local_irq_restore(flags);
|
|
}
|
|
|
|
static struct crypto_alg aes_alg = {
|
|
.cra_name = "aes",
|
|
.cra_driver_name = "aes-fixed-time",
|
|
.cra_priority = 100 + 1,
|
|
.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,
|
|
.cra_cipher.cia_max_keysize = AES_MAX_KEY_SIZE,
|
|
.cra_cipher.cia_setkey = aesti_set_key,
|
|
.cra_cipher.cia_encrypt = aesti_encrypt,
|
|
.cra_cipher.cia_decrypt = aesti_decrypt
|
|
};
|
|
|
|
static int __init aes_init(void)
|
|
{
|
|
return crypto_register_alg(&aes_alg);
|
|
}
|
|
|
|
static void __exit aes_fini(void)
|
|
{
|
|
crypto_unregister_alg(&aes_alg);
|
|
}
|
|
|
|
module_init(aes_init);
|
|
module_exit(aes_fini);
|
|
|
|
MODULE_DESCRIPTION("Generic fixed time AES");
|
|
MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
|
|
MODULE_LICENSE("GPL v2");
|