[linux-block.git] / arch / arm64 / crypto / aes-ce-glue.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * aes-ce-cipher.c - core AES cipher using ARMv8 Crypto Extensions
 *
 * Copyright (C) 2013 - 2017 Linaro Ltd <ard.biesheuvel@linaro.org>
 */

#include <asm/neon.h>
#include <asm/simd.h>
#include <asm/unaligned.h>
#include <crypto/aes.h>
#include <crypto/algapi.h>
#include <crypto/internal/simd.h>
#include <linux/cpufeature.h>
#include <linux/module.h>

#include "aes-ce-setkey.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];
};

asmlinkage void __aes_ce_encrypt(u32 *rk, u8 *out, const u8 *in, int rounds);
asmlinkage void __aes_ce_decrypt(u32 *rk, u8 *out, const u8 *in, int rounds);

asmlinkage u32 __aes_ce_sub(u32 l);
asmlinkage void __aes_ce_invert(struct aes_block *out,
				const struct aes_block *in);

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);

	if (!crypto_simd_usable()) {
		aes_encrypt(ctx, dst, src);
		return;
	}

	kernel_neon_begin();
	__aes_ce_encrypt(ctx->key_enc, dst, src, num_rounds(ctx));
	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);

	if (!crypto_simd_usable()) {
		aes_decrypt(ctx, dst, src);
		return;
	}

	kernel_neon_begin();
	__aes_ce_decrypt(ctx->key_dec, dst, src, num_rounds(ctx));
	kernel_neon_end();
}

int ce_aes_expandkey(struct crypto_aes_ctx *ctx, const u8 *in_key,
		     unsigned int key_len)
{
	/*
	 * The AES key schedule round constants
	 */
	static u8 const rcon[] = {
		0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36,
	};

	u32 kwords = key_len / sizeof(u32);
	struct aes_block *key_enc, *key_dec;
	int i, j;

	if (key_len != AES_KEYSIZE_128 &&
	    key_len != AES_KEYSIZE_192 &&
	    key_len != AES_KEYSIZE_256)
		return -EINVAL;

	ctx->key_length = key_len;
	for (i = 0; i < kwords; i++)
		ctx->key_enc[i] = get_unaligned_le32(in_key + i * sizeof(u32));

	kernel_neon_begin();
	for (i = 0; i < sizeof(rcon); i++) {
		u32 *rki = ctx->key_enc + (i * kwords);
		u32 *rko = rki + kwords;

		rko[0] = ror32(__aes_ce_sub(rki[kwords - 1]), 8) ^ rcon[i] ^ rki[0];
		rko[1] = rko[0] ^ rki[1];
		rko[2] = rko[1] ^ rki[2];
		rko[3] = rko[2] ^ rki[3];

		if (key_len == AES_KEYSIZE_192) {
			if (i >= 7)
				break;
			rko[4] = rko[3] ^ rki[4];
			rko[5] = rko[4] ^ rki[5];
		} else if (key_len == AES_KEYSIZE_256) {
			if (i >= 6)
				break;
			rko[4] = __aes_ce_sub(rko[3]) ^ rki[4];
			rko[5] = rko[4] ^ rki[5];
			rko[6] = rko[5] ^ rki[6];
			rko[7] = rko[6] ^ rki[7];
		}
	}

	/*
	 * Generate the decryption keys for the Equivalent Inverse Cipher.
	 * This involves reversing the order of the round keys, and applying
	 * the Inverse Mix Columns transformation on all but the first and
	 * the last one.
	 */
	key_enc = (struct aes_block *)ctx->key_enc;
	key_dec = (struct aes_block *)ctx->key_dec;
	j = num_rounds(ctx);

	key_dec[0] = key_enc[j];
	for (i = 1, j--; j > 0; i++, j--)
		__aes_ce_invert(key_dec + i, key_enc + j);
	key_dec[i] = key_enc[0];

	kernel_neon_end();
	return 0;
}
EXPORT_SYMBOL(ce_aes_expandkey);

int ce_aes_setkey(struct crypto_tfm *tfm, const u8 *in_key,
		  unsigned int key_len)
{
	struct crypto_aes_ctx *ctx = crypto_tfm_ctx(tfm);

	return ce_aes_expandkey(ctx, in_key, key_len);
}
EXPORT_SYMBOL(ce_aes_setkey);

static struct crypto_alg aes_alg = {
	.cra_name		= "aes",
	.cra_driver_name	= "aes-ce",
	.cra_priority		= 250,
	.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		= ce_aes_setkey,
		.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);
Commit	Line	Data
d2912cb1	1	// SPDX-License-Identifier: GPL-2.0-only
317f2f75 AB	2	/*
	3	* aes-ce-cipher.c - core AES cipher using ARMv8 Crypto Extensions
	4	*
f402e311	5	* Copyright (C) 2013 - 2017 Linaro Ltd <ard.biesheuvel@linaro.org>
317f2f75 AB	6	*/
	7
	8	#include <asm/neon.h>
b8fb993a	9	#include <asm/simd.h>
f402e311	10	#include <asm/unaligned.h>
317f2f75	11	#include <crypto/aes.h>
14386d47	12	#include <crypto/algapi.h>
e52b7023	13	#include <crypto/internal/simd.h>
317f2f75	14	#include <linux/cpufeature.h>
317f2f75 AB	15	#include <linux/module.h>
317f2f75 AB	16
12ac3efe AB	17	#include "aes-ce-setkey.h"
12ac3efe AB	18
317f2f75 AB	19	MODULE_DESCRIPTION("Synchronous AES cipher using ARMv8 Crypto Extensions");
	20	MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
	21	MODULE_LICENSE("GPL v2");
	22
	23	struct aes_block {
	24	u8 b[AES_BLOCK_SIZE];
	25	};
	26
019cd469 AB	27	asmlinkage void __aes_ce_encrypt(u32 rk, u8 out, const u8 *in, int rounds);
	28	asmlinkage void __aes_ce_decrypt(u32 rk, u8 out, const u8 *in, int rounds);
	29
	30	asmlinkage u32 __aes_ce_sub(u32 l);
	31	asmlinkage void __aes_ce_invert(struct aes_block *out,
	32	const struct aes_block *in);
	33
317f2f75 AB	34	static int num_rounds(struct crypto_aes_ctx *ctx)
	35	{
	36	/*
	37	* # of rounds specified by AES:
	38	* 128 bit key 10 rounds
	39	* 192 bit key 12 rounds
	40	* 256 bit key 14 rounds
	41	* => n byte key => 6 + (n/4) rounds
	42	*/
	43	return 6 + ctx->key_length / 4;
	44	}
	45
	46	static void aes_cipher_encrypt(struct crypto_tfm *tfm, u8 dst[], u8 const src[])
	47	{
	48	struct crypto_aes_ctx *ctx = crypto_tfm_ctx(tfm);
317f2f75	49
e52b7023	50	if (!crypto_simd_usable()) {
4d3f9d89	51	aes_encrypt(ctx, dst, src);
b8fb993a AB	52	return;
	53	}
	54
	55	kernel_neon_begin();
019cd469	56	__aes_ce_encrypt(ctx->key_enc, dst, src, num_rounds(ctx));
317f2f75 AB	57	kernel_neon_end();
	58	}
	59
	60	static void aes_cipher_decrypt(struct crypto_tfm *tfm, u8 dst[], u8 const src[])
	61	{
	62	struct crypto_aes_ctx *ctx = crypto_tfm_ctx(tfm);
317f2f75	63
e52b7023	64	if (!crypto_simd_usable()) {
4d3f9d89	65	aes_decrypt(ctx, dst, src);
b8fb993a AB	66	return;
	67	}
	68
	69	kernel_neon_begin();
019cd469	70	__aes_ce_decrypt(ctx->key_dec, dst, src, num_rounds(ctx));
317f2f75 AB	71	kernel_neon_end();
	72	}
	73
12ac3efe AB	74	int ce_aes_expandkey(struct crypto_aes_ctx ctx, const u8 in_key,
	75	unsigned int key_len)
	76	{
	77	/*
	78	* The AES key schedule round constants
	79	*/
	80	static u8 const rcon[] = {
	81	0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36,
	82	};
	83
	84	u32 kwords = key_len / sizeof(u32);
	85	struct aes_block key_enc, key_dec;
	86	int i, j;
	87
	88	if (key_len != AES_KEYSIZE_128 &&
	89	key_len != AES_KEYSIZE_192 &&
	90	key_len != AES_KEYSIZE_256)
	91	return -EINVAL;
	92
12ac3efe	93	ctx->key_length = key_len;
f402e311 AB	94	for (i = 0; i < kwords; i++)
f402e311 AB	95	ctx->key_enc[i] = get_unaligned_le32(in_key + i * sizeof(u32));
12ac3efe	96
b8fb993a	97	kernel_neon_begin();
12ac3efe AB	98	for (i = 0; i < sizeof(rcon); i++) {
	99	u32 rki = ctx->key_enc + (i kwords);
	100	u32 *rko = rki + kwords;
	101
019cd469	102	rko[0] = ror32(__aes_ce_sub(rki[kwords - 1]), 8) ^ rcon[i] ^ rki[0];
12ac3efe AB	103	rko[1] = rko[0] ^ rki[1];
	104	rko[2] = rko[1] ^ rki[2];
	105	rko[3] = rko[2] ^ rki[3];
	106
	107	if (key_len == AES_KEYSIZE_192) {
	108	if (i >= 7)
	109	break;
	110	rko[4] = rko[3] ^ rki[4];
	111	rko[5] = rko[4] ^ rki[5];
	112	} else if (key_len == AES_KEYSIZE_256) {
	113	if (i >= 6)
	114	break;
019cd469	115	rko[4] = __aes_ce_sub(rko[3]) ^ rki[4];
12ac3efe AB	116	rko[5] = rko[4] ^ rki[5];
	117	rko[6] = rko[5] ^ rki[6];
	118	rko[7] = rko[6] ^ rki[7];
	119	}
	120	}
	121
	122	/*
	123	* Generate the decryption keys for the Equivalent Inverse Cipher.
	124	* This involves reversing the order of the round keys, and applying
	125	* the Inverse Mix Columns transformation on all but the first and
	126	* the last one.
	127	*/
	128	key_enc = (struct aes_block *)ctx->key_enc;
	129	key_dec = (struct aes_block *)ctx->key_dec;
	130	j = num_rounds(ctx);
	131
	132	key_dec[0] = key_enc[j];
	133	for (i = 1, j--; j > 0; i++, j--)
019cd469	134	__aes_ce_invert(key_dec + i, key_enc + j);
12ac3efe AB	135	key_dec[i] = key_enc[0];
	136
	137	kernel_neon_end();
	138	return 0;
	139	}
	140	EXPORT_SYMBOL(ce_aes_expandkey);
	141
	142	int ce_aes_setkey(struct crypto_tfm tfm, const u8 in_key,
	143	unsigned int key_len)
	144	{
	145	struct crypto_aes_ctx *ctx = crypto_tfm_ctx(tfm);
12ac3efe	146
674f368a	147	return ce_aes_expandkey(ctx, in_key, key_len);
12ac3efe AB	148	}
	149	EXPORT_SYMBOL(ce_aes_setkey);
	150
317f2f75 AB	151	static struct crypto_alg aes_alg = {
	152	.cra_name = "aes",
	153	.cra_driver_name = "aes-ce",
08c6781c	154	.cra_priority = 250,
317f2f75 AB	155	.cra_flags = CRYPTO_ALG_TYPE_CIPHER,
	156	.cra_blocksize = AES_BLOCK_SIZE,
	157	.cra_ctxsize = sizeof(struct crypto_aes_ctx),
	158	.cra_module = THIS_MODULE,
	159	.cra_cipher = {
	160	.cia_min_keysize = AES_MIN_KEY_SIZE,
	161	.cia_max_keysize = AES_MAX_KEY_SIZE,
12ac3efe	162	.cia_setkey = ce_aes_setkey,
317f2f75 AB	163	.cia_encrypt = aes_cipher_encrypt,
	164	.cia_decrypt = aes_cipher_decrypt
	165	}
	166	};
	167
	168	static int __init aes_mod_init(void)
	169	{
	170	return crypto_register_alg(&aes_alg);
	171	}
	172
	173	static void __exit aes_mod_exit(void)
	174	{
	175	crypto_unregister_alg(&aes_alg);
	176	}
	177
	178	module_cpu_feature_match(AES, aes_mod_init);
	179	module_exit(aes_mod_exit);