linux/arch/x86/crypto/blowfish_glue.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Glue Code for assembler optimized version of Blowfish
 *
 * Copyright (c) 2011 Jussi Kivilinna <jussi.kivilinna@mbnet.fi>
 *
 * CBC & ECB parts based on code (crypto/cbc.c,ecb.c) by:
 *   Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
 */

#include <crypto/algapi.h>
#include <crypto/blowfish.h>
#include <crypto/internal/skcipher.h>
#include <linux/crypto.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/types.h>

#include "ecb_cbc_helpers.h"

/* regular block cipher functions */
asmlinkage void blowfish_enc_blk(struct bf_ctx *ctx, u8 *dst, const u8 *src);
asmlinkage void blowfish_dec_blk(struct bf_ctx *ctx, u8 *dst, const u8 *src);

/* 4-way parallel cipher functions */
asmlinkage void blowfish_enc_blk_4way(struct bf_ctx *ctx, u8 *dst,
				      const u8 *src);
asmlinkage void __blowfish_dec_blk_4way(struct bf_ctx *ctx, u8 *dst,
					const u8 *src, bool cbc);

static inline void blowfish_dec_ecb_4way(struct bf_ctx *ctx, u8 *dst,
					     const u8 *src)
{
	return __blowfish_dec_blk_4way(ctx, dst, src, false);
}

static inline void blowfish_dec_cbc_4way(struct bf_ctx *ctx, u8 *dst,
					     const u8 *src)
{
	return __blowfish_dec_blk_4way(ctx, dst, src, true);
}

static void blowfish_encrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
{
	blowfish_enc_blk(crypto_tfm_ctx(tfm), dst, src);
}

static void blowfish_decrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
{
	blowfish_dec_blk(crypto_tfm_ctx(tfm), dst, src);
}

static int blowfish_setkey_skcipher(struct crypto_skcipher *tfm,
				    const u8 *key, unsigned int keylen)
{
	return blowfish_setkey(&tfm->base, key, keylen);
}

static int ecb_encrypt(struct skcipher_request *req)
{
	ECB_WALK_START(req, BF_BLOCK_SIZE, -1);
	ECB_BLOCK(4, blowfish_enc_blk_4way);
	ECB_BLOCK(1, blowfish_enc_blk);
	ECB_WALK_END();
}

static int ecb_decrypt(struct skcipher_request *req)
{
	ECB_WALK_START(req, BF_BLOCK_SIZE, -1);
	ECB_BLOCK(4, blowfish_dec_ecb_4way);
	ECB_BLOCK(1, blowfish_dec_blk);
	ECB_WALK_END();
}

static int cbc_encrypt(struct skcipher_request *req)
{
	CBC_WALK_START(req, BF_BLOCK_SIZE, -1);
	CBC_ENC_BLOCK(blowfish_enc_blk);
	CBC_WALK_END();
}

static int cbc_decrypt(struct skcipher_request *req)
{
	CBC_WALK_START(req, BF_BLOCK_SIZE, -1);
	CBC_DEC_BLOCK(4, blowfish_dec_cbc_4way);
	CBC_DEC_BLOCK(1, blowfish_dec_blk);
	CBC_WALK_END();
}

static struct crypto_alg bf_cipher_alg = {
	.cra_name		= "blowfish",
	.cra_driver_name	= "blowfish-asm",
	.cra_priority		= 200,
	.cra_flags		= CRYPTO_ALG_TYPE_CIPHER,
	.cra_blocksize		= BF_BLOCK_SIZE,
	.cra_ctxsize		= sizeof(struct bf_ctx),
	.cra_alignmask		= 0,
	.cra_module		= THIS_MODULE,
	.cra_u = {
		.cipher = {
			.cia_min_keysize	= BF_MIN_KEY_SIZE,
			.cia_max_keysize	= BF_MAX_KEY_SIZE,
			.cia_setkey		= blowfish_setkey,
			.cia_encrypt		= blowfish_encrypt,
			.cia_decrypt		= blowfish_decrypt,
		}
	}
};

static struct skcipher_alg bf_skcipher_algs[] = {
	{
		.base.cra_name		= "ecb(blowfish)",
		.base.cra_driver_name	= "ecb-blowfish-asm",
		.base.cra_priority	= 300,
		.base.cra_blocksize	= BF_BLOCK_SIZE,
		.base.cra_ctxsize	= sizeof(struct bf_ctx),
		.base.cra_module	= THIS_MODULE,
		.min_keysize		= BF_MIN_KEY_SIZE,
		.max_keysize		= BF_MAX_KEY_SIZE,
		.setkey			= blowfish_setkey_skcipher,
		.encrypt		= ecb_encrypt,
		.decrypt		= ecb_decrypt,
	}, {
		.base.cra_name		= "cbc(blowfish)",
		.base.cra_driver_name	= "cbc-blowfish-asm",
		.base.cra_priority	= 300,
		.base.cra_blocksize	= BF_BLOCK_SIZE,
		.base.cra_ctxsize	= sizeof(struct bf_ctx),
		.base.cra_module	= THIS_MODULE,
		.min_keysize		= BF_MIN_KEY_SIZE,
		.max_keysize		= BF_MAX_KEY_SIZE,
		.ivsize			= BF_BLOCK_SIZE,
		.setkey			= blowfish_setkey_skcipher,
		.encrypt		= cbc_encrypt,
		.decrypt		= cbc_decrypt,
	},
};

static bool is_blacklisted_cpu(void)
{
	if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL)
		return false;

	if (boot_cpu_data.x86 == 0x0f) {
		/*
		 * On Pentium 4, blowfish-x86_64 is slower than generic C
		 * implementation because use of 64bit rotates (which are really
		 * slow on P4). Therefore blacklist P4s.
		 */
		return true;
	}

	return false;
}

static int force;
module_param(force, int, 0);
MODULE_PARM_DESC(force, "Force module load, ignore CPU blacklist");

static int __init blowfish_init(void)
{
	int err;

	if (!force && is_blacklisted_cpu()) {
		printk(KERN_INFO
			"blowfish-x86_64: performance on this CPU "
			"would be suboptimal: disabling "
			"blowfish-x86_64.\n");
		return -ENODEV;
	}

	err = crypto_register_alg(&bf_cipher_alg);
	if (err)
		return err;

	err = crypto_register_skciphers(bf_skcipher_algs,
					ARRAY_SIZE(bf_skcipher_algs));
	if (err)
		crypto_unregister_alg(&bf_cipher_alg);

	return err;
}

static void __exit blowfish_fini(void)
{
	crypto_unregister_alg(&bf_cipher_alg);
	crypto_unregister_skciphers(bf_skcipher_algs,
				    ARRAY_SIZE(bf_skcipher_algs));
}

module_init(blowfish_init);
module_exit(blowfish_fini);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Blowfish Cipher Algorithm, asm optimized");
MODULE_ALIAS_CRYPTO("blowfish");
MODULE_ALIAS_CRYPTO("blowfish-asm");