linux/arch/arm64/crypto/aes-glue.c

/*
 * linux/arch/arm64/crypto/aes-glue.c - wrapper code for ARMv8 AES
 *
 * Copyright (C) 2013 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 <asm/hwcap.h>
#include <crypto/aes.h>
#include <crypto/ablk_helper.h>
#include <crypto/algapi.h>
#include <linux/module.h>
#include <linux/cpufeature.h>

#ifdef USE_V8_CRYPTO_EXTENSIONS
#define MODE			"ce"
#define PRIO			300
#define aes_ecb_encrypt		ce_aes_ecb_encrypt
#define aes_ecb_decrypt		ce_aes_ecb_decrypt
#define aes_cbc_encrypt		ce_aes_cbc_encrypt
#define aes_cbc_decrypt		ce_aes_cbc_decrypt
#define aes_ctr_encrypt		ce_aes_ctr_encrypt
#define aes_xts_encrypt		ce_aes_xts_encrypt
#define aes_xts_decrypt		ce_aes_xts_decrypt
MODULE_DESCRIPTION("AES-ECB/CBC/CTR/XTS using ARMv8 Crypto Extensions");
#else
#define MODE			"neon"
#define PRIO			200
#define aes_ecb_encrypt		neon_aes_ecb_encrypt
#define aes_ecb_decrypt		neon_aes_ecb_decrypt
#define aes_cbc_encrypt		neon_aes_cbc_encrypt
#define aes_cbc_decrypt		neon_aes_cbc_decrypt
#define aes_ctr_encrypt		neon_aes_ctr_encrypt
#define aes_xts_encrypt		neon_aes_xts_encrypt
#define aes_xts_decrypt		neon_aes_xts_decrypt
MODULE_DESCRIPTION("AES-ECB/CBC/CTR/XTS using ARMv8 NEON");
MODULE_ALIAS("ecb(aes)");
MODULE_ALIAS("cbc(aes)");
MODULE_ALIAS("ctr(aes)");
MODULE_ALIAS("xts(aes)");
#endif

MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
MODULE_LICENSE("GPL v2");

/* defined in aes-modes.S */
asmlinkage void aes_ecb_encrypt(u8 out[], u8 const in[], u8 const rk[],
				int rounds, int blocks, int first);
asmlinkage void aes_ecb_decrypt(u8 out[], u8 const in[], u8 const rk[],
				int rounds, int blocks, int first);

asmlinkage void aes_cbc_encrypt(u8 out[], u8 const in[], u8 const rk[],
				int rounds, int blocks, u8 iv[], int first);
asmlinkage void aes_cbc_decrypt(u8 out[], u8 const in[], u8 const rk[],
				int rounds, int blocks, u8 iv[], int first);

asmlinkage void aes_ctr_encrypt(u8 out[], u8 const in[], u8 const rk[],
				int rounds, int blocks, u8 ctr[], int first);

asmlinkage void aes_xts_encrypt(u8 out[], u8 const in[], u8 const rk1[],
				int rounds, int blocks, u8 const rk2[], u8 iv[],
				int first);
asmlinkage void aes_xts_decrypt(u8 out[], u8 const in[], u8 const rk1[],
				int rounds, int blocks, u8 const rk2[], u8 iv[],
				int first);

struct crypto_aes_xts_ctx {
	struct crypto_aes_ctx key1;
	struct crypto_aes_ctx __aligned(8) key2;
};

static int xts_set_key(struct crypto_tfm *tfm, const u8 *in_key,
		       unsigned int key_len)
{
	struct crypto_aes_xts_ctx *ctx = crypto_tfm_ctx(tfm);
	int ret;

	ret = crypto_aes_expand_key(&ctx->key1, in_key, key_len / 2);
	if (!ret)
		ret = crypto_aes_expand_key(&ctx->key2, &in_key[key_len / 2],
					    key_len / 2);
	if (!ret)
		return 0;

	tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
	return -EINVAL;
}

static int ecb_encrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
		       struct scatterlist *src, unsigned int nbytes)
{
	struct crypto_aes_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
	int err, first, rounds = 6 + ctx->key_length / 4;
	struct blkcipher_walk walk;
	unsigned int blocks;

	desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
	blkcipher_walk_init(&walk, dst, src, nbytes);
	err = blkcipher_walk_virt(desc, &walk);

	kernel_neon_begin();
	for (first = 1; (blocks = (walk.nbytes / AES_BLOCK_SIZE)); first = 0) {
		aes_ecb_encrypt(walk.dst.virt.addr, walk.src.virt.addr,
				(u8 *)ctx->key_enc, rounds, blocks, first);
		err = blkcipher_walk_done(desc, &walk, 0);
	}
	kernel_neon_end();
	return err;
}

static int ecb_decrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
		       struct scatterlist *src, unsigned int nbytes)
{
	struct crypto_aes_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
	int err, first, rounds = 6 + ctx->key_length / 4;
	struct blkcipher_walk walk;
	unsigned int blocks;

	desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
	blkcipher_walk_init(&walk, dst, src, nbytes);
	err = blkcipher_walk_virt(desc, &walk);

	kernel_neon_begin();
	for (first = 1; (blocks = (walk.nbytes / AES_BLOCK_SIZE)); first = 0) {
		aes_ecb_decrypt(walk.dst.virt.addr, walk.src.virt.addr,
				(u8 *)ctx->key_dec, rounds, blocks, first);
		err = blkcipher_walk_done(desc, &walk, 0);
	}
	kernel_neon_end();
	return err;
}

static int cbc_encrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
		       struct scatterlist *src, unsigned int nbytes)
{
	struct crypto_aes_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
	int err, first, rounds = 6 + ctx->key_length / 4;
	struct blkcipher_walk walk;
	unsigned int blocks;

	desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
	blkcipher_walk_init(&walk, dst, src, nbytes);
	err = blkcipher_walk_virt(desc, &walk);

	kernel_neon_begin();
	for (first = 1; (blocks = (walk.nbytes / AES_BLOCK_SIZE)); first = 0) {
		aes_cbc_encrypt(walk.dst.virt.addr, walk.src.virt.addr,
				(u8 *)ctx->key_enc, rounds, blocks, walk.iv,
				first);
		err = blkcipher_walk_done(desc, &walk, 0);
	}
	kernel_neon_end();
	return err;
}

static int cbc_decrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
		       struct scatterlist *src, unsigned int nbytes)
{
	struct crypto_aes_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
	int err, first, rounds = 6 + ctx->key_length / 4;
	struct blkcipher_walk walk;
	unsigned int blocks;

	desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
	blkcipher_walk_init(&walk, dst, src, nbytes);
	err = blkcipher_walk_virt(desc, &walk);

	kernel_neon_begin();
	for (first = 1; (blocks = (walk.nbytes / AES_BLOCK_SIZE)); first = 0) {
		aes_cbc_decrypt(walk.dst.virt.addr, walk.src.virt.addr,
				(u8 *)ctx->key_dec, rounds, blocks, walk.iv,
				first);
		err = blkcipher_walk_done(desc, &walk, 0);
	}
	kernel_neon_end();
	return err;
}

static int ctr_encrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
		       struct scatterlist *src, unsigned int nbytes)
{
	struct crypto_aes_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
	int err, first, rounds = 6 + ctx->key_length / 4;
	struct blkcipher_walk walk;
	int blocks;

	desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
	blkcipher_walk_init(&walk, dst, src, nbytes);
	err = blkcipher_walk_virt_block(desc, &walk, AES_BLOCK_SIZE);

	first = 1;
	kernel_neon_begin();
	while ((blocks = (walk.nbytes / AES_BLOCK_SIZE))) {
		aes_ctr_encrypt(walk.dst.virt.addr, walk.src.virt.addr,
				(u8 *)ctx->key_enc, rounds, blocks, walk.iv,
				first);
		first = 0;
		nbytes -= blocks * AES_BLOCK_SIZE;
		if (nbytes && nbytes == walk.nbytes % AES_BLOCK_SIZE)
			break;
		err = blkcipher_walk_done(desc, &walk,
					  walk.nbytes % AES_BLOCK_SIZE);
	}
	if (nbytes) {
		u8 *tdst = walk.dst.virt.addr + blocks * AES_BLOCK_SIZE;
		u8 *tsrc = walk.src.virt.addr + blocks * AES_BLOCK_SIZE;
		u8 __aligned(8) tail[AES_BLOCK_SIZE];

		/*
		 * Minimum alignment is 8 bytes, so if nbytes is <= 8, we need
		 * to tell aes_ctr_encrypt() to only read half a block.
		 */
		blocks = (nbytes <= 8) ? -1 : 1;

		aes_ctr_encrypt(tail, tsrc, (u8 *)ctx->key_enc, rounds,
				blocks, walk.iv, first);
		memcpy(tdst, tail, nbytes);
		err = blkcipher_walk_done(desc, &walk, 0);
	}
	kernel_neon_end();

	return err;
}

static int xts_encrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
		       struct scatterlist *src, unsigned int nbytes)
{
	struct crypto_aes_xts_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
	int err, first, rounds = 6 + ctx->key1.key_length / 4;
	struct blkcipher_walk walk;
	unsigned int blocks;

	desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
	blkcipher_walk_init(&walk, dst, src, nbytes);
	err = blkcipher_walk_virt(desc, &walk);

	kernel_neon_begin();
	for (first = 1; (blocks = (walk.nbytes / AES_BLOCK_SIZE)); first = 0) {
		aes_xts_encrypt(walk.dst.virt.addr, walk.src.virt.addr,
				(u8 *)ctx->key1.key_enc, rounds, blocks,
				(u8 *)ctx->key2.key_enc, walk.iv, first);
		err = blkcipher_walk_done(desc, &walk, 0);
	}
	kernel_neon_end();

	return err;
}

static int xts_decrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
		       struct scatterlist *src, unsigned int nbytes)
{
	struct crypto_aes_xts_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
	int err, first, rounds = 6 + ctx->key1.key_length / 4;
	struct blkcipher_walk walk;
	unsigned int blocks;

	desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
	blkcipher_walk_init(&walk, dst, src, nbytes);
	err = blkcipher_walk_virt(desc, &walk);

	kernel_neon_begin();
	for (first = 1; (blocks = (walk.nbytes / AES_BLOCK_SIZE)); first = 0) {
		aes_xts_decrypt(walk.dst.virt.addr, walk.src.virt.addr,
				(u8 *)ctx->key1.key_dec, rounds, blocks,
				(u8 *)ctx->key2.key_enc, walk.iv, first);
		err = blkcipher_walk_done(desc, &walk, 0);
	}
	kernel_neon_end();

	return err;
}

static struct crypto_alg aes_algs[] = { {
	.cra_name		= "__ecb-aes-" MODE,
	.cra_driver_name	= "__driver-ecb-aes-" MODE,
	.cra_priority		= 0,
	.cra_flags		= CRYPTO_ALG_TYPE_BLKCIPHER,
	.cra_blocksize		= AES_BLOCK_SIZE,
	.cra_ctxsize		= sizeof(struct crypto_aes_ctx),
	.cra_alignmask		= 7,
	.cra_type		= &crypto_blkcipher_type,
	.cra_module		= THIS_MODULE,
	.cra_blkcipher = {
		.min_keysize	= AES_MIN_KEY_SIZE,
		.max_keysize	= AES_MAX_KEY_SIZE,
		.ivsize		= AES_BLOCK_SIZE,
		.setkey		= crypto_aes_set_key,
		.encrypt	= ecb_encrypt,
		.decrypt	= ecb_decrypt,
	},
}, {
	.cra_name		= "__cbc-aes-" MODE,
	.cra_driver_name	= "__driver-cbc-aes-" MODE,
	.cra_priority		= 0,
	.cra_flags		= CRYPTO_ALG_TYPE_BLKCIPHER,
	.cra_blocksize		= AES_BLOCK_SIZE,
	.cra_ctxsize		= sizeof(struct crypto_aes_ctx),
	.cra_alignmask		= 7,
	.cra_type		= &crypto_blkcipher_type,
	.cra_module		= THIS_MODULE,
	.cra_blkcipher = {
		.min_keysize	= AES_MIN_KEY_SIZE,
		.max_keysize	= AES_MAX_KEY_SIZE,
		.ivsize		= AES_BLOCK_SIZE,
		.setkey		= crypto_aes_set_key,
		.encrypt	= cbc_encrypt,
		.decrypt	= cbc_decrypt,
	},
}, {
	.cra_name		= "__ctr-aes-" MODE,
	.cra_driver_name	= "__driver-ctr-aes-" MODE,
	.cra_priority		= 0,
	.cra_flags		= CRYPTO_ALG_TYPE_BLKCIPHER,
	.cra_blocksize		= 1,
	.cra_ctxsize		= sizeof(struct crypto_aes_ctx),
	.cra_alignmask		= 7,
	.cra_type		= &crypto_blkcipher_type,
	.cra_module		= THIS_MODULE,
	.cra_blkcipher = {
		.min_keysize	= AES_MIN_KEY_SIZE,
		.max_keysize	= AES_MAX_KEY_SIZE,
		.ivsize		= AES_BLOCK_SIZE,
		.setkey		= crypto_aes_set_key,
		.encrypt	= ctr_encrypt,
		.decrypt	= ctr_encrypt,
	},
}, {
	.cra_name		= "__xts-aes-" MODE,
	.cra_driver_name	= "__driver-xts-aes-" MODE,
	.cra_priority		= 0,
	.cra_flags		= CRYPTO_ALG_TYPE_BLKCIPHER,
	.cra_blocksize		= AES_BLOCK_SIZE,
	.cra_ctxsize		= sizeof(struct crypto_aes_xts_ctx),
	.cra_alignmask		= 7,
	.cra_type		= &crypto_blkcipher_type,
	.cra_module		= THIS_MODULE,
	.cra_blkcipher = {
		.min_keysize	= 2 * AES_MIN_KEY_SIZE,
		.max_keysize	= 2 * AES_MAX_KEY_SIZE,
		.ivsize		= AES_BLOCK_SIZE,
		.setkey		= xts_set_key,
		.encrypt	= xts_encrypt,
		.decrypt	= xts_decrypt,
	},
}, {
	.cra_name		= "ecb(aes)",
	.cra_driver_name	= "ecb-aes-" MODE,
	.cra_priority		= PRIO,
	.cra_flags		= CRYPTO_ALG_TYPE_ABLKCIPHER|CRYPTO_ALG_ASYNC,
	.cra_blocksize		= AES_BLOCK_SIZE,
	.cra_ctxsize		= sizeof(struct async_helper_ctx),
	.cra_alignmask		= 7,
	.cra_type		= &crypto_ablkcipher_type,
	.cra_module		= THIS_MODULE,
	.cra_init		= ablk_init,
	.cra_exit		= ablk_exit,
	.cra_ablkcipher = {
		.min_keysize	= AES_MIN_KEY_SIZE,
		.max_keysize	= AES_MAX_KEY_SIZE,
		.ivsize		= AES_BLOCK_SIZE,
		.setkey		= ablk_set_key,
		.encrypt	= ablk_encrypt,
		.decrypt	= ablk_decrypt,
	}
}, {
	.cra_name		= "cbc(aes)",
	.cra_driver_name	= "cbc-aes-" MODE,
	.cra_priority		= PRIO,
	.cra_flags		= CRYPTO_ALG_TYPE_ABLKCIPHER|CRYPTO_ALG_ASYNC,
	.cra_blocksize		= AES_BLOCK_SIZE,
	.cra_ctxsize		= sizeof(struct async_helper_ctx),
	.cra_alignmask		= 7,
	.cra_type		= &crypto_ablkcipher_type,
	.cra_module		= THIS_MODULE,
	.cra_init		= ablk_init,
	.cra_exit		= ablk_exit,
	.cra_ablkcipher = {
		.min_keysize	= AES_MIN_KEY_SIZE,
		.max_keysize	= AES_MAX_KEY_SIZE,
		.ivsize		= AES_BLOCK_SIZE,
		.setkey		= ablk_set_key,
		.encrypt	= ablk_encrypt,
		.decrypt	= ablk_decrypt,
	}
}, {
	.cra_name		= "ctr(aes)",
	.cra_driver_name	= "ctr-aes-" MODE,
	.cra_priority		= PRIO,
	.cra_flags		= CRYPTO_ALG_TYPE_ABLKCIPHER|CRYPTO_ALG_ASYNC,
	.cra_blocksize		= 1,
	.cra_ctxsize		= sizeof(struct async_helper_ctx),
	.cra_alignmask		= 7,
	.cra_type		= &crypto_ablkcipher_type,
	.cra_module		= THIS_MODULE,
	.cra_init		= ablk_init,
	.cra_exit		= ablk_exit,
	.cra_ablkcipher = {
		.min_keysize	= AES_MIN_KEY_SIZE,
		.max_keysize	= AES_MAX_KEY_SIZE,
		.ivsize		= AES_BLOCK_SIZE,
		.setkey		= ablk_set_key,
		.encrypt	= ablk_encrypt,
		.decrypt	= ablk_decrypt,
	}
}, {
	.cra_name		= "xts(aes)",
	.cra_driver_name	= "xts-aes-" MODE,
	.cra_priority		= PRIO,
	.cra_flags		= CRYPTO_ALG_TYPE_ABLKCIPHER|CRYPTO_ALG_ASYNC,
	.cra_blocksize		= AES_BLOCK_SIZE,
	.cra_ctxsize		= sizeof(struct async_helper_ctx),
	.cra_alignmask		= 7,
	.cra_type		= &crypto_ablkcipher_type,
	.cra_module		= THIS_MODULE,
	.cra_init		= ablk_init,
	.cra_exit		= ablk_exit,
	.cra_ablkcipher = {
		.min_keysize	= 2 * AES_MIN_KEY_SIZE,
		.max_keysize	= 2 * AES_MAX_KEY_SIZE,
		.ivsize		= AES_BLOCK_SIZE,
		.setkey		= ablk_set_key,
		.encrypt	= ablk_encrypt,
		.decrypt	= ablk_decrypt,
	}
} };

static int __init aes_init(void)
{
	return crypto_register_algs(aes_algs, ARRAY_SIZE(aes_algs));
}

static void __exit aes_exit(void)
{
	crypto_unregister_algs(aes_algs, ARRAY_SIZE(aes_algs));
}

#ifdef USE_V8_CRYPTO_EXTENSIONS
module_cpu_feature_match(AES, aes_init);
#else
module_init(aes_init);
#endif
module_exit(aes_exit);