xref: /linux/arch/x86/crypto/twofish_glue_3way.c (revision 888dc273ea4e7ca332a6f73d10dfc8f2b212c803)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Glue Code for 3-way parallel assembler optimized version of Twofish
4  *
5  * Copyright (c) 2011 Jussi Kivilinna <jussi.kivilinna@mbnet.fi>
6  */
7 
8 #include <asm/crypto/glue_helper.h>
9 #include <asm/crypto/twofish.h>
10 #include <crypto/algapi.h>
11 #include <crypto/b128ops.h>
12 #include <crypto/internal/skcipher.h>
13 #include <crypto/twofish.h>
14 #include <linux/crypto.h>
15 #include <linux/init.h>
16 #include <linux/module.h>
17 #include <linux/types.h>
18 
19 EXPORT_SYMBOL_GPL(__twofish_enc_blk_3way);
20 EXPORT_SYMBOL_GPL(twofish_dec_blk_3way);
21 
22 static int twofish_setkey_skcipher(struct crypto_skcipher *tfm,
23 				   const u8 *key, unsigned int keylen)
24 {
25 	return twofish_setkey(&tfm->base, key, keylen);
26 }
27 
28 static inline void twofish_enc_blk_3way(struct twofish_ctx *ctx, u8 *dst,
29 					const u8 *src)
30 {
31 	__twofish_enc_blk_3way(ctx, dst, src, false);
32 }
33 
34 static inline void twofish_enc_blk_xor_3way(struct twofish_ctx *ctx, u8 *dst,
35 					    const u8 *src)
36 {
37 	__twofish_enc_blk_3way(ctx, dst, src, true);
38 }
39 
40 void twofish_dec_blk_cbc_3way(void *ctx, u128 *dst, const u128 *src)
41 {
42 	u128 ivs[2];
43 
44 	ivs[0] = src[0];
45 	ivs[1] = src[1];
46 
47 	twofish_dec_blk_3way(ctx, (u8 *)dst, (u8 *)src);
48 
49 	u128_xor(&dst[1], &dst[1], &ivs[0]);
50 	u128_xor(&dst[2], &dst[2], &ivs[1]);
51 }
52 EXPORT_SYMBOL_GPL(twofish_dec_blk_cbc_3way);
53 
54 void twofish_enc_blk_ctr(void *ctx, u128 *dst, const u128 *src, le128 *iv)
55 {
56 	be128 ctrblk;
57 
58 	if (dst != src)
59 		*dst = *src;
60 
61 	le128_to_be128(&ctrblk, iv);
62 	le128_inc(iv);
63 
64 	twofish_enc_blk(ctx, (u8 *)&ctrblk, (u8 *)&ctrblk);
65 	u128_xor(dst, dst, (u128 *)&ctrblk);
66 }
67 EXPORT_SYMBOL_GPL(twofish_enc_blk_ctr);
68 
69 void twofish_enc_blk_ctr_3way(void *ctx, u128 *dst, const u128 *src,
70 			      le128 *iv)
71 {
72 	be128 ctrblks[3];
73 
74 	if (dst != src) {
75 		dst[0] = src[0];
76 		dst[1] = src[1];
77 		dst[2] = src[2];
78 	}
79 
80 	le128_to_be128(&ctrblks[0], iv);
81 	le128_inc(iv);
82 	le128_to_be128(&ctrblks[1], iv);
83 	le128_inc(iv);
84 	le128_to_be128(&ctrblks[2], iv);
85 	le128_inc(iv);
86 
87 	twofish_enc_blk_xor_3way(ctx, (u8 *)dst, (u8 *)ctrblks);
88 }
89 EXPORT_SYMBOL_GPL(twofish_enc_blk_ctr_3way);
90 
91 static const struct common_glue_ctx twofish_enc = {
92 	.num_funcs = 2,
93 	.fpu_blocks_limit = -1,
94 
95 	.funcs = { {
96 		.num_blocks = 3,
97 		.fn_u = { .ecb = GLUE_FUNC_CAST(twofish_enc_blk_3way) }
98 	}, {
99 		.num_blocks = 1,
100 		.fn_u = { .ecb = GLUE_FUNC_CAST(twofish_enc_blk) }
101 	} }
102 };
103 
104 static const struct common_glue_ctx twofish_ctr = {
105 	.num_funcs = 2,
106 	.fpu_blocks_limit = -1,
107 
108 	.funcs = { {
109 		.num_blocks = 3,
110 		.fn_u = { .ecb = GLUE_FUNC_CAST(twofish_enc_blk_ctr_3way) }
111 	}, {
112 		.num_blocks = 1,
113 		.fn_u = { .ecb = GLUE_FUNC_CAST(twofish_enc_blk_ctr) }
114 	} }
115 };
116 
117 static const struct common_glue_ctx twofish_dec = {
118 	.num_funcs = 2,
119 	.fpu_blocks_limit = -1,
120 
121 	.funcs = { {
122 		.num_blocks = 3,
123 		.fn_u = { .ecb = GLUE_FUNC_CAST(twofish_dec_blk_3way) }
124 	}, {
125 		.num_blocks = 1,
126 		.fn_u = { .ecb = GLUE_FUNC_CAST(twofish_dec_blk) }
127 	} }
128 };
129 
130 static const struct common_glue_ctx twofish_dec_cbc = {
131 	.num_funcs = 2,
132 	.fpu_blocks_limit = -1,
133 
134 	.funcs = { {
135 		.num_blocks = 3,
136 		.fn_u = { .cbc = GLUE_CBC_FUNC_CAST(twofish_dec_blk_cbc_3way) }
137 	}, {
138 		.num_blocks = 1,
139 		.fn_u = { .cbc = GLUE_CBC_FUNC_CAST(twofish_dec_blk) }
140 	} }
141 };
142 
143 static int ecb_encrypt(struct skcipher_request *req)
144 {
145 	return glue_ecb_req_128bit(&twofish_enc, req);
146 }
147 
148 static int ecb_decrypt(struct skcipher_request *req)
149 {
150 	return glue_ecb_req_128bit(&twofish_dec, req);
151 }
152 
153 static int cbc_encrypt(struct skcipher_request *req)
154 {
155 	return glue_cbc_encrypt_req_128bit(GLUE_FUNC_CAST(twofish_enc_blk),
156 					   req);
157 }
158 
159 static int cbc_decrypt(struct skcipher_request *req)
160 {
161 	return glue_cbc_decrypt_req_128bit(&twofish_dec_cbc, req);
162 }
163 
164 static int ctr_crypt(struct skcipher_request *req)
165 {
166 	return glue_ctr_req_128bit(&twofish_ctr, req);
167 }
168 
169 static struct skcipher_alg tf_skciphers[] = {
170 	{
171 		.base.cra_name		= "ecb(twofish)",
172 		.base.cra_driver_name	= "ecb-twofish-3way",
173 		.base.cra_priority	= 300,
174 		.base.cra_blocksize	= TF_BLOCK_SIZE,
175 		.base.cra_ctxsize	= sizeof(struct twofish_ctx),
176 		.base.cra_module	= THIS_MODULE,
177 		.min_keysize		= TF_MIN_KEY_SIZE,
178 		.max_keysize		= TF_MAX_KEY_SIZE,
179 		.setkey			= twofish_setkey_skcipher,
180 		.encrypt		= ecb_encrypt,
181 		.decrypt		= ecb_decrypt,
182 	}, {
183 		.base.cra_name		= "cbc(twofish)",
184 		.base.cra_driver_name	= "cbc-twofish-3way",
185 		.base.cra_priority	= 300,
186 		.base.cra_blocksize	= TF_BLOCK_SIZE,
187 		.base.cra_ctxsize	= sizeof(struct twofish_ctx),
188 		.base.cra_module	= THIS_MODULE,
189 		.min_keysize		= TF_MIN_KEY_SIZE,
190 		.max_keysize		= TF_MAX_KEY_SIZE,
191 		.ivsize			= TF_BLOCK_SIZE,
192 		.setkey			= twofish_setkey_skcipher,
193 		.encrypt		= cbc_encrypt,
194 		.decrypt		= cbc_decrypt,
195 	}, {
196 		.base.cra_name		= "ctr(twofish)",
197 		.base.cra_driver_name	= "ctr-twofish-3way",
198 		.base.cra_priority	= 300,
199 		.base.cra_blocksize	= 1,
200 		.base.cra_ctxsize	= sizeof(struct twofish_ctx),
201 		.base.cra_module	= THIS_MODULE,
202 		.min_keysize		= TF_MIN_KEY_SIZE,
203 		.max_keysize		= TF_MAX_KEY_SIZE,
204 		.ivsize			= TF_BLOCK_SIZE,
205 		.chunksize		= TF_BLOCK_SIZE,
206 		.setkey			= twofish_setkey_skcipher,
207 		.encrypt		= ctr_crypt,
208 		.decrypt		= ctr_crypt,
209 	},
210 };
211 
212 static bool is_blacklisted_cpu(void)
213 {
214 	if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL)
215 		return false;
216 
217 	if (boot_cpu_data.x86 == 0x06 &&
218 		(boot_cpu_data.x86_model == 0x1c ||
219 		 boot_cpu_data.x86_model == 0x26 ||
220 		 boot_cpu_data.x86_model == 0x36)) {
221 		/*
222 		 * On Atom, twofish-3way is slower than original assembler
223 		 * implementation. Twofish-3way trades off some performance in
224 		 * storing blocks in 64bit registers to allow three blocks to
225 		 * be processed parallel. Parallel operation then allows gaining
226 		 * more performance than was trade off, on out-of-order CPUs.
227 		 * However Atom does not benefit from this parallellism and
228 		 * should be blacklisted.
229 		 */
230 		return true;
231 	}
232 
233 	if (boot_cpu_data.x86 == 0x0f) {
234 		/*
235 		 * On Pentium 4, twofish-3way is slower than original assembler
236 		 * implementation because excessive uses of 64bit rotate and
237 		 * left-shifts (which are really slow on P4) needed to store and
238 		 * handle 128bit block in two 64bit registers.
239 		 */
240 		return true;
241 	}
242 
243 	return false;
244 }
245 
246 static int force;
247 module_param(force, int, 0);
248 MODULE_PARM_DESC(force, "Force module load, ignore CPU blacklist");
249 
250 static int __init init(void)
251 {
252 	if (!force && is_blacklisted_cpu()) {
253 		printk(KERN_INFO
254 			"twofish-x86_64-3way: performance on this CPU "
255 			"would be suboptimal: disabling "
256 			"twofish-x86_64-3way.\n");
257 		return -ENODEV;
258 	}
259 
260 	return crypto_register_skciphers(tf_skciphers,
261 					 ARRAY_SIZE(tf_skciphers));
262 }
263 
264 static void __exit fini(void)
265 {
266 	crypto_unregister_skciphers(tf_skciphers, ARRAY_SIZE(tf_skciphers));
267 }
268 
269 module_init(init);
270 module_exit(fini);
271 
272 MODULE_LICENSE("GPL");
273 MODULE_DESCRIPTION("Twofish Cipher Algorithm, 3-way parallel asm optimized");
274 MODULE_ALIAS_CRYPTO("twofish");
275 MODULE_ALIAS_CRYPTO("twofish-asm");
276