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(const void *ctx, u8 *dst, const u8 *src)
29 {
30 	__twofish_enc_blk_3way(ctx, dst, src, false);
31 }
32 
33 static inline void twofish_enc_blk_xor_3way(const void *ctx, u8 *dst,
34 					    const u8 *src)
35 {
36 	__twofish_enc_blk_3way(ctx, dst, src, true);
37 }
38 
39 void twofish_dec_blk_cbc_3way(const void *ctx, u8 *d, const u8 *s)
40 {
41 	u128 ivs[2];
42 	u128 *dst = (u128 *)d;
43 	const u128 *src = (const u128 *)s;
44 
45 	ivs[0] = src[0];
46 	ivs[1] = src[1];
47 
48 	twofish_dec_blk_3way(ctx, (u8 *)dst, (u8 *)src);
49 
50 	u128_xor(&dst[1], &dst[1], &ivs[0]);
51 	u128_xor(&dst[2], &dst[2], &ivs[1]);
52 }
53 EXPORT_SYMBOL_GPL(twofish_dec_blk_cbc_3way);
54 
55 void twofish_enc_blk_ctr(const void *ctx, u8 *d, const u8 *s, le128 *iv)
56 {
57 	be128 ctrblk;
58 	u128 *dst = (u128 *)d;
59 	const u128 *src = (const u128 *)s;
60 
61 	if (dst != src)
62 		*dst = *src;
63 
64 	le128_to_be128(&ctrblk, iv);
65 	le128_inc(iv);
66 
67 	twofish_enc_blk(ctx, (u8 *)&ctrblk, (u8 *)&ctrblk);
68 	u128_xor(dst, dst, (u128 *)&ctrblk);
69 }
70 EXPORT_SYMBOL_GPL(twofish_enc_blk_ctr);
71 
72 void twofish_enc_blk_ctr_3way(const void *ctx, u8 *d, const u8 *s, le128 *iv)
73 {
74 	be128 ctrblks[3];
75 	u128 *dst = (u128 *)d;
76 	const u128 *src = (const u128 *)s;
77 
78 	if (dst != src) {
79 		dst[0] = src[0];
80 		dst[1] = src[1];
81 		dst[2] = src[2];
82 	}
83 
84 	le128_to_be128(&ctrblks[0], iv);
85 	le128_inc(iv);
86 	le128_to_be128(&ctrblks[1], iv);
87 	le128_inc(iv);
88 	le128_to_be128(&ctrblks[2], iv);
89 	le128_inc(iv);
90 
91 	twofish_enc_blk_xor_3way(ctx, (u8 *)dst, (u8 *)ctrblks);
92 }
93 EXPORT_SYMBOL_GPL(twofish_enc_blk_ctr_3way);
94 
95 static const struct common_glue_ctx twofish_enc = {
96 	.num_funcs = 2,
97 	.fpu_blocks_limit = -1,
98 
99 	.funcs = { {
100 		.num_blocks = 3,
101 		.fn_u = { .ecb = twofish_enc_blk_3way }
102 	}, {
103 		.num_blocks = 1,
104 		.fn_u = { .ecb = twofish_enc_blk }
105 	} }
106 };
107 
108 static const struct common_glue_ctx twofish_ctr = {
109 	.num_funcs = 2,
110 	.fpu_blocks_limit = -1,
111 
112 	.funcs = { {
113 		.num_blocks = 3,
114 		.fn_u = { .ctr = twofish_enc_blk_ctr_3way }
115 	}, {
116 		.num_blocks = 1,
117 		.fn_u = { .ctr = twofish_enc_blk_ctr }
118 	} }
119 };
120 
121 static const struct common_glue_ctx twofish_dec = {
122 	.num_funcs = 2,
123 	.fpu_blocks_limit = -1,
124 
125 	.funcs = { {
126 		.num_blocks = 3,
127 		.fn_u = { .ecb = twofish_dec_blk_3way }
128 	}, {
129 		.num_blocks = 1,
130 		.fn_u = { .ecb = twofish_dec_blk }
131 	} }
132 };
133 
134 static const struct common_glue_ctx twofish_dec_cbc = {
135 	.num_funcs = 2,
136 	.fpu_blocks_limit = -1,
137 
138 	.funcs = { {
139 		.num_blocks = 3,
140 		.fn_u = { .cbc = twofish_dec_blk_cbc_3way }
141 	}, {
142 		.num_blocks = 1,
143 		.fn_u = { .cbc = twofish_dec_blk }
144 	} }
145 };
146 
147 static int ecb_encrypt(struct skcipher_request *req)
148 {
149 	return glue_ecb_req_128bit(&twofish_enc, req);
150 }
151 
152 static int ecb_decrypt(struct skcipher_request *req)
153 {
154 	return glue_ecb_req_128bit(&twofish_dec, req);
155 }
156 
157 static int cbc_encrypt(struct skcipher_request *req)
158 {
159 	return glue_cbc_encrypt_req_128bit(twofish_enc_blk, req);
160 }
161 
162 static int cbc_decrypt(struct skcipher_request *req)
163 {
164 	return glue_cbc_decrypt_req_128bit(&twofish_dec_cbc, req);
165 }
166 
167 static int ctr_crypt(struct skcipher_request *req)
168 {
169 	return glue_ctr_req_128bit(&twofish_ctr, req);
170 }
171 
172 static struct skcipher_alg tf_skciphers[] = {
173 	{
174 		.base.cra_name		= "ecb(twofish)",
175 		.base.cra_driver_name	= "ecb-twofish-3way",
176 		.base.cra_priority	= 300,
177 		.base.cra_blocksize	= TF_BLOCK_SIZE,
178 		.base.cra_ctxsize	= sizeof(struct twofish_ctx),
179 		.base.cra_module	= THIS_MODULE,
180 		.min_keysize		= TF_MIN_KEY_SIZE,
181 		.max_keysize		= TF_MAX_KEY_SIZE,
182 		.setkey			= twofish_setkey_skcipher,
183 		.encrypt		= ecb_encrypt,
184 		.decrypt		= ecb_decrypt,
185 	}, {
186 		.base.cra_name		= "cbc(twofish)",
187 		.base.cra_driver_name	= "cbc-twofish-3way",
188 		.base.cra_priority	= 300,
189 		.base.cra_blocksize	= TF_BLOCK_SIZE,
190 		.base.cra_ctxsize	= sizeof(struct twofish_ctx),
191 		.base.cra_module	= THIS_MODULE,
192 		.min_keysize		= TF_MIN_KEY_SIZE,
193 		.max_keysize		= TF_MAX_KEY_SIZE,
194 		.ivsize			= TF_BLOCK_SIZE,
195 		.setkey			= twofish_setkey_skcipher,
196 		.encrypt		= cbc_encrypt,
197 		.decrypt		= cbc_decrypt,
198 	}, {
199 		.base.cra_name		= "ctr(twofish)",
200 		.base.cra_driver_name	= "ctr-twofish-3way",
201 		.base.cra_priority	= 300,
202 		.base.cra_blocksize	= 1,
203 		.base.cra_ctxsize	= sizeof(struct twofish_ctx),
204 		.base.cra_module	= THIS_MODULE,
205 		.min_keysize		= TF_MIN_KEY_SIZE,
206 		.max_keysize		= TF_MAX_KEY_SIZE,
207 		.ivsize			= TF_BLOCK_SIZE,
208 		.chunksize		= TF_BLOCK_SIZE,
209 		.setkey			= twofish_setkey_skcipher,
210 		.encrypt		= ctr_crypt,
211 		.decrypt		= ctr_crypt,
212 	},
213 };
214 
215 static bool is_blacklisted_cpu(void)
216 {
217 	if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL)
218 		return false;
219 
220 	if (boot_cpu_data.x86 == 0x06 &&
221 		(boot_cpu_data.x86_model == 0x1c ||
222 		 boot_cpu_data.x86_model == 0x26 ||
223 		 boot_cpu_data.x86_model == 0x36)) {
224 		/*
225 		 * On Atom, twofish-3way is slower than original assembler
226 		 * implementation. Twofish-3way trades off some performance in
227 		 * storing blocks in 64bit registers to allow three blocks to
228 		 * be processed parallel. Parallel operation then allows gaining
229 		 * more performance than was trade off, on out-of-order CPUs.
230 		 * However Atom does not benefit from this parallellism and
231 		 * should be blacklisted.
232 		 */
233 		return true;
234 	}
235 
236 	if (boot_cpu_data.x86 == 0x0f) {
237 		/*
238 		 * On Pentium 4, twofish-3way is slower than original assembler
239 		 * implementation because excessive uses of 64bit rotate and
240 		 * left-shifts (which are really slow on P4) needed to store and
241 		 * handle 128bit block in two 64bit registers.
242 		 */
243 		return true;
244 	}
245 
246 	return false;
247 }
248 
249 static int force;
250 module_param(force, int, 0);
251 MODULE_PARM_DESC(force, "Force module load, ignore CPU blacklist");
252 
253 static int __init init(void)
254 {
255 	if (!force && is_blacklisted_cpu()) {
256 		printk(KERN_INFO
257 			"twofish-x86_64-3way: performance on this CPU "
258 			"would be suboptimal: disabling "
259 			"twofish-x86_64-3way.\n");
260 		return -ENODEV;
261 	}
262 
263 	return crypto_register_skciphers(tf_skciphers,
264 					 ARRAY_SIZE(tf_skciphers));
265 }
266 
267 static void __exit fini(void)
268 {
269 	crypto_unregister_skciphers(tf_skciphers, ARRAY_SIZE(tf_skciphers));
270 }
271 
272 module_init(init);
273 module_exit(fini);
274 
275 MODULE_LICENSE("GPL");
276 MODULE_DESCRIPTION("Twofish Cipher Algorithm, 3-way parallel asm optimized");
277 MODULE_ALIAS_CRYPTO("twofish");
278 MODULE_ALIAS_CRYPTO("twofish-asm");
279