1 /*
2  * Glue Code for assembler optimized version of TWOFISH
3  *
4  * Originally Twofish for GPG
5  * By Matthew Skala <mskala@ansuz.sooke.bc.ca>, July 26, 1998
6  * 256-bit key length added March 20, 1999
7  * Some modifications to reduce the text size by Werner Koch, April, 1998
8  * Ported to the kerneli patch by Marc Mutz <Marc@Mutz.com>
9  * Ported to CryptoAPI by Colin Slater <hoho@tacomeat.net>
10  *
11  * The original author has disclaimed all copyright interest in this
12  * code and thus put it in the public domain. The subsequent authors
13  * have put this under the GNU General Public License.
14  *
15  * This program is free software; you can redistribute it and/or modify
16  * it under the terms of the GNU General Public License as published by
17  * the Free Software Foundation; either version 2 of the License, or
18  * (at your option) any later version.
19  *
20  * This program is distributed in the hope that it will be useful,
21  * but WITHOUT ANY WARRANTY; without even the implied warranty of
22  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
23  * GNU General Public License for more details.
24  *
25  * You should have received a copy of the GNU General Public License
26  * along with this program; if not, write to the Free Software
27  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307
28  * USA
29  *
30  * This code is a "clean room" implementation, written from the paper
31  * _Twofish: A 128-Bit Block Cipher_ by Bruce Schneier, John Kelsey,
32  * Doug Whiting, David Wagner, Chris Hall, and Niels Ferguson, available
33  * through http://www.counterpane.com/twofish.html
34  *
35  * For background information on multiplication in finite fields, used for
36  * the matrix operations in the key schedule, see the book _Contemporary
37  * Abstract Algebra_ by Joseph A. Gallian, especially chapter 22 in the
38  * Third Edition.
39  */
40 
41 #include <crypto/twofish.h>
42 #include <linux/crypto.h>
43 #include <linux/init.h>
44 #include <linux/module.h>
45 #include <linux/types.h>
46 
47 asmlinkage void twofish_enc_blk(struct twofish_ctx *ctx, u8 *dst,
48 				const u8 *src);
49 EXPORT_SYMBOL_GPL(twofish_enc_blk);
50 asmlinkage void twofish_dec_blk(struct twofish_ctx *ctx, u8 *dst,
51 				const u8 *src);
52 EXPORT_SYMBOL_GPL(twofish_dec_blk);
53 
twofish_encrypt(struct crypto_tfm * tfm,u8 * dst,const u8 * src)54 static void twofish_encrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
55 {
56 	twofish_enc_blk(crypto_tfm_ctx(tfm), dst, src);
57 }
58 
twofish_decrypt(struct crypto_tfm * tfm,u8 * dst,const u8 * src)59 static void twofish_decrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
60 {
61 	twofish_dec_blk(crypto_tfm_ctx(tfm), dst, src);
62 }
63 
64 static struct crypto_alg alg = {
65 	.cra_name		=	"twofish",
66 	.cra_driver_name	=	"twofish-asm",
67 	.cra_priority		=	200,
68 	.cra_flags		=	CRYPTO_ALG_TYPE_CIPHER,
69 	.cra_blocksize		=	TF_BLOCK_SIZE,
70 	.cra_ctxsize		=	sizeof(struct twofish_ctx),
71 	.cra_alignmask		=	0,
72 	.cra_module		=	THIS_MODULE,
73 	.cra_u			=	{
74 		.cipher = {
75 			.cia_min_keysize	=	TF_MIN_KEY_SIZE,
76 			.cia_max_keysize	=	TF_MAX_KEY_SIZE,
77 			.cia_setkey		=	twofish_setkey,
78 			.cia_encrypt		=	twofish_encrypt,
79 			.cia_decrypt		=	twofish_decrypt
80 		}
81 	}
82 };
83 
twofish_glue_init(void)84 static int __init twofish_glue_init(void)
85 {
86 	return crypto_register_alg(&alg);
87 }
88 
twofish_glue_fini(void)89 static void __exit twofish_glue_fini(void)
90 {
91 	crypto_unregister_alg(&alg);
92 }
93 
94 module_init(twofish_glue_init);
95 module_exit(twofish_glue_fini);
96 
97 MODULE_LICENSE("GPL");
98 MODULE_DESCRIPTION ("Twofish Cipher Algorithm, asm optimized");
99 MODULE_ALIAS_CRYPTO("twofish");
100 MODULE_ALIAS_CRYPTO("twofish-asm");
101