1 /*
2  * Glue Code for SSE2 assembler versions of Serpent Cipher
3  *
4  * Copyright (c) 2011 Jussi Kivilinna <jussi.kivilinna@mbnet.fi>
5  *
6  * Glue code based on aesni-intel_glue.c by:
7  *  Copyright (C) 2008, Intel Corp.
8  *    Author: Huang Ying <ying.huang@intel.com>
9  *
10  * CBC & ECB parts based on code (crypto/cbc.c,ecb.c) by:
11  *   Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
12  * CTR part based on code (crypto/ctr.c) by:
13  *   (C) Copyright IBM Corp. 2007 - Joy Latten <latten@us.ibm.com>
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  */
31 
32 #include <linux/module.h>
33 #include <linux/types.h>
34 #include <linux/crypto.h>
35 #include <linux/err.h>
36 #include <crypto/algapi.h>
37 #include <crypto/b128ops.h>
38 #include <crypto/internal/simd.h>
39 #include <crypto/serpent.h>
40 #include <asm/crypto/serpent-sse2.h>
41 #include <asm/crypto/glue_helper.h>
42 
43 static int serpent_setkey_skcipher(struct crypto_skcipher *tfm,
44 				   const u8 *key, unsigned int keylen)
45 {
46 	return __serpent_setkey(crypto_skcipher_ctx(tfm), key, keylen);
47 }
48 
49 static void serpent_decrypt_cbc_xway(void *ctx, u128 *dst, const u128 *src)
50 {
51 	u128 ivs[SERPENT_PARALLEL_BLOCKS - 1];
52 	unsigned int j;
53 
54 	for (j = 0; j < SERPENT_PARALLEL_BLOCKS - 1; j++)
55 		ivs[j] = src[j];
56 
57 	serpent_dec_blk_xway(ctx, (u8 *)dst, (u8 *)src);
58 
59 	for (j = 0; j < SERPENT_PARALLEL_BLOCKS - 1; j++)
60 		u128_xor(dst + (j + 1), dst + (j + 1), ivs + j);
61 }
62 
63 static void serpent_crypt_ctr(void *ctx, u128 *dst, const u128 *src, le128 *iv)
64 {
65 	be128 ctrblk;
66 
67 	le128_to_be128(&ctrblk, iv);
68 	le128_inc(iv);
69 
70 	__serpent_encrypt(ctx, (u8 *)&ctrblk, (u8 *)&ctrblk);
71 	u128_xor(dst, src, (u128 *)&ctrblk);
72 }
73 
74 static void serpent_crypt_ctr_xway(void *ctx, u128 *dst, const u128 *src,
75 				   le128 *iv)
76 {
77 	be128 ctrblks[SERPENT_PARALLEL_BLOCKS];
78 	unsigned int i;
79 
80 	for (i = 0; i < SERPENT_PARALLEL_BLOCKS; i++) {
81 		if (dst != src)
82 			dst[i] = src[i];
83 
84 		le128_to_be128(&ctrblks[i], iv);
85 		le128_inc(iv);
86 	}
87 
88 	serpent_enc_blk_xway_xor(ctx, (u8 *)dst, (u8 *)ctrblks);
89 }
90 
91 static const struct common_glue_ctx serpent_enc = {
92 	.num_funcs = 2,
93 	.fpu_blocks_limit = SERPENT_PARALLEL_BLOCKS,
94 
95 	.funcs = { {
96 		.num_blocks = SERPENT_PARALLEL_BLOCKS,
97 		.fn_u = { .ecb = GLUE_FUNC_CAST(serpent_enc_blk_xway) }
98 	}, {
99 		.num_blocks = 1,
100 		.fn_u = { .ecb = GLUE_FUNC_CAST(__serpent_encrypt) }
101 	} }
102 };
103 
104 static const struct common_glue_ctx serpent_ctr = {
105 	.num_funcs = 2,
106 	.fpu_blocks_limit = SERPENT_PARALLEL_BLOCKS,
107 
108 	.funcs = { {
109 		.num_blocks = SERPENT_PARALLEL_BLOCKS,
110 		.fn_u = { .ctr = GLUE_CTR_FUNC_CAST(serpent_crypt_ctr_xway) }
111 	}, {
112 		.num_blocks = 1,
113 		.fn_u = { .ctr = GLUE_CTR_FUNC_CAST(serpent_crypt_ctr) }
114 	} }
115 };
116 
117 static const struct common_glue_ctx serpent_dec = {
118 	.num_funcs = 2,
119 	.fpu_blocks_limit = SERPENT_PARALLEL_BLOCKS,
120 
121 	.funcs = { {
122 		.num_blocks = SERPENT_PARALLEL_BLOCKS,
123 		.fn_u = { .ecb = GLUE_FUNC_CAST(serpent_dec_blk_xway) }
124 	}, {
125 		.num_blocks = 1,
126 		.fn_u = { .ecb = GLUE_FUNC_CAST(__serpent_decrypt) }
127 	} }
128 };
129 
130 static const struct common_glue_ctx serpent_dec_cbc = {
131 	.num_funcs = 2,
132 	.fpu_blocks_limit = SERPENT_PARALLEL_BLOCKS,
133 
134 	.funcs = { {
135 		.num_blocks = SERPENT_PARALLEL_BLOCKS,
136 		.fn_u = { .cbc = GLUE_CBC_FUNC_CAST(serpent_decrypt_cbc_xway) }
137 	}, {
138 		.num_blocks = 1,
139 		.fn_u = { .cbc = GLUE_CBC_FUNC_CAST(__serpent_decrypt) }
140 	} }
141 };
142 
143 static int ecb_encrypt(struct skcipher_request *req)
144 {
145 	return glue_ecb_req_128bit(&serpent_enc, req);
146 }
147 
148 static int ecb_decrypt(struct skcipher_request *req)
149 {
150 	return glue_ecb_req_128bit(&serpent_dec, req);
151 }
152 
153 static int cbc_encrypt(struct skcipher_request *req)
154 {
155 	return glue_cbc_encrypt_req_128bit(GLUE_FUNC_CAST(__serpent_encrypt),
156 					   req);
157 }
158 
159 static int cbc_decrypt(struct skcipher_request *req)
160 {
161 	return glue_cbc_decrypt_req_128bit(&serpent_dec_cbc, req);
162 }
163 
164 static int ctr_crypt(struct skcipher_request *req)
165 {
166 	return glue_ctr_req_128bit(&serpent_ctr, req);
167 }
168 
169 static struct skcipher_alg serpent_algs[] = {
170 	{
171 		.base.cra_name		= "__ecb(serpent)",
172 		.base.cra_driver_name	= "__ecb-serpent-sse2",
173 		.base.cra_priority	= 400,
174 		.base.cra_flags		= CRYPTO_ALG_INTERNAL,
175 		.base.cra_blocksize	= SERPENT_BLOCK_SIZE,
176 		.base.cra_ctxsize	= sizeof(struct serpent_ctx),
177 		.base.cra_module	= THIS_MODULE,
178 		.min_keysize		= SERPENT_MIN_KEY_SIZE,
179 		.max_keysize		= SERPENT_MAX_KEY_SIZE,
180 		.setkey			= serpent_setkey_skcipher,
181 		.encrypt		= ecb_encrypt,
182 		.decrypt		= ecb_decrypt,
183 	}, {
184 		.base.cra_name		= "__cbc(serpent)",
185 		.base.cra_driver_name	= "__cbc-serpent-sse2",
186 		.base.cra_priority	= 400,
187 		.base.cra_flags		= CRYPTO_ALG_INTERNAL,
188 		.base.cra_blocksize	= SERPENT_BLOCK_SIZE,
189 		.base.cra_ctxsize	= sizeof(struct serpent_ctx),
190 		.base.cra_module	= THIS_MODULE,
191 		.min_keysize		= SERPENT_MIN_KEY_SIZE,
192 		.max_keysize		= SERPENT_MAX_KEY_SIZE,
193 		.ivsize			= SERPENT_BLOCK_SIZE,
194 		.setkey			= serpent_setkey_skcipher,
195 		.encrypt		= cbc_encrypt,
196 		.decrypt		= cbc_decrypt,
197 	}, {
198 		.base.cra_name		= "__ctr(serpent)",
199 		.base.cra_driver_name	= "__ctr-serpent-sse2",
200 		.base.cra_priority	= 400,
201 		.base.cra_flags		= CRYPTO_ALG_INTERNAL,
202 		.base.cra_blocksize	= 1,
203 		.base.cra_ctxsize	= sizeof(struct serpent_ctx),
204 		.base.cra_module	= THIS_MODULE,
205 		.min_keysize		= SERPENT_MIN_KEY_SIZE,
206 		.max_keysize		= SERPENT_MAX_KEY_SIZE,
207 		.ivsize			= SERPENT_BLOCK_SIZE,
208 		.chunksize		= SERPENT_BLOCK_SIZE,
209 		.setkey			= serpent_setkey_skcipher,
210 		.encrypt		= ctr_crypt,
211 		.decrypt		= ctr_crypt,
212 	},
213 };
214 
215 static struct simd_skcipher_alg *serpent_simd_algs[ARRAY_SIZE(serpent_algs)];
216 
217 static int __init serpent_sse2_init(void)
218 {
219 	if (!boot_cpu_has(X86_FEATURE_XMM2)) {
220 		printk(KERN_INFO "SSE2 instructions are not detected.\n");
221 		return -ENODEV;
222 	}
223 
224 	return simd_register_skciphers_compat(serpent_algs,
225 					      ARRAY_SIZE(serpent_algs),
226 					      serpent_simd_algs);
227 }
228 
229 static void __exit serpent_sse2_exit(void)
230 {
231 	simd_unregister_skciphers(serpent_algs, ARRAY_SIZE(serpent_algs),
232 				  serpent_simd_algs);
233 }
234 
235 module_init(serpent_sse2_init);
236 module_exit(serpent_sse2_exit);
237 
238 MODULE_DESCRIPTION("Serpent Cipher Algorithm, SSE2 optimized");
239 MODULE_LICENSE("GPL");
240 MODULE_ALIAS_CRYPTO("serpent");
241