[linux.git] / crypto / aes_ti.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Scalar fixed time AES core transform
 *
 * Copyright (C) 2017 Linaro Ltd <[email protected]>
 */

#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 <[email protected]>");
MODULE_LICENSE("GPL v2");
Commit	Line	Data
d2912cb1	1	// SPDX-License-Identifier: GPL-2.0-only
b5e0b032 AB	2	/*
	3	* Scalar fixed time AES core transform
	4	*
	5	* Copyright (C) 2017 Linaro Ltd <[email protected]>
b5e0b032 AB	6	*/
	7
	8	#include <crypto/aes.h>
	9	#include <linux/crypto.h>
	10	#include <linux/module.h>
b5e0b032 AB	11
	12	static int aesti_set_key(struct crypto_tfm tfm, const u8 in_key,
	13	unsigned int key_len)
	14	{
	15	struct crypto_aes_ctx *ctx = crypto_tfm_ctx(tfm);
b5e0b032	16
e59c1c98	17	return aes_expandkey(ctx, in_key, key_len);
b5e0b032 AB	18	}
	19
	20	static void aesti_encrypt(struct crypto_tfm tfm, u8 out, const u8 *in)
	21	{
	22	const struct crypto_aes_ctx *ctx = crypto_tfm_ctx(tfm);
0a6a40c2	23	unsigned long flags;
b5e0b032	24
0a6a40c2 EB	25	/*
	26	* Temporarily disable interrupts to avoid races where cachelines are
	27	* evicted when the CPU is interrupted to do something else.
	28	*/
	29	local_irq_save(flags);
	30
e59c1c98	31	aes_encrypt(ctx, out, in);
0a6a40c2 EB	32
0a6a40c2 EB	33	local_irq_restore(flags);
b5e0b032 AB	34	}
	35
	36	static void aesti_decrypt(struct crypto_tfm tfm, u8 out, const u8 *in)
	37	{
	38	const struct crypto_aes_ctx *ctx = crypto_tfm_ctx(tfm);
0a6a40c2	39	unsigned long flags;
b5e0b032	40
0a6a40c2 EB	41	/*
	42	* Temporarily disable interrupts to avoid races where cachelines are
	43	* evicted when the CPU is interrupted to do something else.
	44	*/
	45	local_irq_save(flags);
	46
e59c1c98	47	aes_decrypt(ctx, out, in);
0a6a40c2 EB	48
0a6a40c2 EB	49	local_irq_restore(flags);
b5e0b032 AB	50	}
	51
	52	static struct crypto_alg aes_alg = {
	53	.cra_name = "aes",
	54	.cra_driver_name = "aes-fixed-time",
	55	.cra_priority = 100 + 1,
	56	.cra_flags = CRYPTO_ALG_TYPE_CIPHER,
	57	.cra_blocksize = AES_BLOCK_SIZE,
	58	.cra_ctxsize = sizeof(struct crypto_aes_ctx),
	59	.cra_module = THIS_MODULE,
	60
	61	.cra_cipher.cia_min_keysize = AES_MIN_KEY_SIZE,
	62	.cra_cipher.cia_max_keysize = AES_MAX_KEY_SIZE,
	63	.cra_cipher.cia_setkey = aesti_set_key,
	64	.cra_cipher.cia_encrypt = aesti_encrypt,
	65	.cra_cipher.cia_decrypt = aesti_decrypt
	66	};
	67
	68	static int __init aes_init(void)
	69	{
	70	return crypto_register_alg(&aes_alg);
	71	}
	72
	73	static void __exit aes_fini(void)
	74	{
	75	crypto_unregister_alg(&aes_alg);
	76	}
	77
	78	module_init(aes_init);
	79	module_exit(aes_fini);
	80
	81	MODULE_DESCRIPTION("Generic fixed time AES");
	82	MODULE_AUTHOR("Ard Biesheuvel <[email protected]>");
	83	MODULE_LICENSE("GPL v2");