1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3  * SM4 Cipher Algorithm, using ARMv8 NEON
4  * as specified in
5  * https://tools.ietf.org/id/draft-ribose-cfrg-sm4-10.html
6  *
7  * Copyright (C) 2022, Alibaba Group.
8  * Copyright (C) 2022 Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
9  */
10 
11 #include <linux/module.h>
12 #include <linux/crypto.h>
13 #include <linux/kernel.h>
14 #include <linux/cpufeature.h>
15 #include <asm/neon.h>
16 #include <asm/simd.h>
17 #include <crypto/internal/simd.h>
18 #include <crypto/internal/skcipher.h>
19 #include <crypto/sm4.h>
20 
21 asmlinkage void sm4_neon_crypt(const u32 *rkey, u8 *dst, const u8 *src,
22 			       unsigned int nblocks);
23 asmlinkage void sm4_neon_cbc_dec(const u32 *rkey_dec, u8 *dst, const u8 *src,
24 				 u8 *iv, unsigned int nblocks);
25 asmlinkage void sm4_neon_cfb_dec(const u32 *rkey_enc, u8 *dst, const u8 *src,
26 				 u8 *iv, unsigned int nblocks);
27 asmlinkage void sm4_neon_ctr_crypt(const u32 *rkey_enc, u8 *dst, const u8 *src,
28 				   u8 *iv, unsigned int nblocks);
29 
30 static int sm4_setkey(struct crypto_skcipher *tfm, const u8 *key,
31 		      unsigned int key_len)
32 {
33 	struct sm4_ctx *ctx = crypto_skcipher_ctx(tfm);
34 
35 	return sm4_expandkey(ctx, key, key_len);
36 }
37 
38 static int sm4_ecb_do_crypt(struct skcipher_request *req, const u32 *rkey)
39 {
40 	struct skcipher_walk walk;
41 	unsigned int nbytes;
42 	int err;
43 
44 	err = skcipher_walk_virt(&walk, req, false);
45 
46 	while ((nbytes = walk.nbytes) > 0) {
47 		const u8 *src = walk.src.virt.addr;
48 		u8 *dst = walk.dst.virt.addr;
49 		unsigned int nblocks;
50 
51 		nblocks = nbytes / SM4_BLOCK_SIZE;
52 		if (nblocks) {
53 			kernel_neon_begin();
54 
55 			sm4_neon_crypt(rkey, dst, src, nblocks);
56 
57 			kernel_neon_end();
58 		}
59 
60 		err = skcipher_walk_done(&walk, nbytes % SM4_BLOCK_SIZE);
61 	}
62 
63 	return err;
64 }
65 
66 static int sm4_ecb_encrypt(struct skcipher_request *req)
67 {
68 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
69 	struct sm4_ctx *ctx = crypto_skcipher_ctx(tfm);
70 
71 	return sm4_ecb_do_crypt(req, ctx->rkey_enc);
72 }
73 
74 static int sm4_ecb_decrypt(struct skcipher_request *req)
75 {
76 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
77 	struct sm4_ctx *ctx = crypto_skcipher_ctx(tfm);
78 
79 	return sm4_ecb_do_crypt(req, ctx->rkey_dec);
80 }
81 
82 static int sm4_cbc_encrypt(struct skcipher_request *req)
83 {
84 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
85 	struct sm4_ctx *ctx = crypto_skcipher_ctx(tfm);
86 	struct skcipher_walk walk;
87 	unsigned int nbytes;
88 	int err;
89 
90 	err = skcipher_walk_virt(&walk, req, false);
91 
92 	while ((nbytes = walk.nbytes) > 0) {
93 		const u8 *iv = walk.iv;
94 		const u8 *src = walk.src.virt.addr;
95 		u8 *dst = walk.dst.virt.addr;
96 
97 		while (nbytes >= SM4_BLOCK_SIZE) {
98 			crypto_xor_cpy(dst, src, iv, SM4_BLOCK_SIZE);
99 			sm4_crypt_block(ctx->rkey_enc, dst, dst);
100 			iv = dst;
101 			src += SM4_BLOCK_SIZE;
102 			dst += SM4_BLOCK_SIZE;
103 			nbytes -= SM4_BLOCK_SIZE;
104 		}
105 		if (iv != walk.iv)
106 			memcpy(walk.iv, iv, SM4_BLOCK_SIZE);
107 
108 		err = skcipher_walk_done(&walk, nbytes);
109 	}
110 
111 	return err;
112 }
113 
114 static int sm4_cbc_decrypt(struct skcipher_request *req)
115 {
116 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
117 	struct sm4_ctx *ctx = crypto_skcipher_ctx(tfm);
118 	struct skcipher_walk walk;
119 	unsigned int nbytes;
120 	int err;
121 
122 	err = skcipher_walk_virt(&walk, req, false);
123 
124 	while ((nbytes = walk.nbytes) > 0) {
125 		const u8 *src = walk.src.virt.addr;
126 		u8 *dst = walk.dst.virt.addr;
127 		unsigned int nblocks;
128 
129 		nblocks = nbytes / SM4_BLOCK_SIZE;
130 		if (nblocks) {
131 			kernel_neon_begin();
132 
133 			sm4_neon_cbc_dec(ctx->rkey_dec, dst, src,
134 					 walk.iv, nblocks);
135 
136 			kernel_neon_end();
137 		}
138 
139 		err = skcipher_walk_done(&walk, nbytes % SM4_BLOCK_SIZE);
140 	}
141 
142 	return err;
143 }
144 
145 static int sm4_cfb_encrypt(struct skcipher_request *req)
146 {
147 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
148 	struct sm4_ctx *ctx = crypto_skcipher_ctx(tfm);
149 	struct skcipher_walk walk;
150 	unsigned int nbytes;
151 	int err;
152 
153 	err = skcipher_walk_virt(&walk, req, false);
154 
155 	while ((nbytes = walk.nbytes) > 0) {
156 		u8 keystream[SM4_BLOCK_SIZE];
157 		const u8 *iv = walk.iv;
158 		const u8 *src = walk.src.virt.addr;
159 		u8 *dst = walk.dst.virt.addr;
160 
161 		while (nbytes >= SM4_BLOCK_SIZE) {
162 			sm4_crypt_block(ctx->rkey_enc, keystream, iv);
163 			crypto_xor_cpy(dst, src, keystream, SM4_BLOCK_SIZE);
164 			iv = dst;
165 			src += SM4_BLOCK_SIZE;
166 			dst += SM4_BLOCK_SIZE;
167 			nbytes -= SM4_BLOCK_SIZE;
168 		}
169 		if (iv != walk.iv)
170 			memcpy(walk.iv, iv, SM4_BLOCK_SIZE);
171 
172 		/* tail */
173 		if (walk.nbytes == walk.total && nbytes > 0) {
174 			sm4_crypt_block(ctx->rkey_enc, keystream, walk.iv);
175 			crypto_xor_cpy(dst, src, keystream, nbytes);
176 			nbytes = 0;
177 		}
178 
179 		err = skcipher_walk_done(&walk, nbytes);
180 	}
181 
182 	return err;
183 }
184 
185 static int sm4_cfb_decrypt(struct skcipher_request *req)
186 {
187 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
188 	struct sm4_ctx *ctx = crypto_skcipher_ctx(tfm);
189 	struct skcipher_walk walk;
190 	unsigned int nbytes;
191 	int err;
192 
193 	err = skcipher_walk_virt(&walk, req, false);
194 
195 	while ((nbytes = walk.nbytes) > 0) {
196 		const u8 *src = walk.src.virt.addr;
197 		u8 *dst = walk.dst.virt.addr;
198 		unsigned int nblocks;
199 
200 		nblocks = nbytes / SM4_BLOCK_SIZE;
201 		if (nblocks) {
202 			kernel_neon_begin();
203 
204 			sm4_neon_cfb_dec(ctx->rkey_enc, dst, src,
205 					 walk.iv, nblocks);
206 
207 			kernel_neon_end();
208 
209 			dst += nblocks * SM4_BLOCK_SIZE;
210 			src += nblocks * SM4_BLOCK_SIZE;
211 			nbytes -= nblocks * SM4_BLOCK_SIZE;
212 		}
213 
214 		/* tail */
215 		if (walk.nbytes == walk.total && nbytes > 0) {
216 			u8 keystream[SM4_BLOCK_SIZE];
217 
218 			sm4_crypt_block(ctx->rkey_enc, keystream, walk.iv);
219 			crypto_xor_cpy(dst, src, keystream, nbytes);
220 			nbytes = 0;
221 		}
222 
223 		err = skcipher_walk_done(&walk, nbytes);
224 	}
225 
226 	return err;
227 }
228 
229 static int sm4_ctr_crypt(struct skcipher_request *req)
230 {
231 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
232 	struct sm4_ctx *ctx = crypto_skcipher_ctx(tfm);
233 	struct skcipher_walk walk;
234 	unsigned int nbytes;
235 	int err;
236 
237 	err = skcipher_walk_virt(&walk, req, false);
238 
239 	while ((nbytes = walk.nbytes) > 0) {
240 		const u8 *src = walk.src.virt.addr;
241 		u8 *dst = walk.dst.virt.addr;
242 		unsigned int nblocks;
243 
244 		nblocks = nbytes / SM4_BLOCK_SIZE;
245 		if (nblocks) {
246 			kernel_neon_begin();
247 
248 			sm4_neon_ctr_crypt(ctx->rkey_enc, dst, src,
249 					   walk.iv, nblocks);
250 
251 			kernel_neon_end();
252 
253 			dst += nblocks * SM4_BLOCK_SIZE;
254 			src += nblocks * SM4_BLOCK_SIZE;
255 			nbytes -= nblocks * SM4_BLOCK_SIZE;
256 		}
257 
258 		/* tail */
259 		if (walk.nbytes == walk.total && nbytes > 0) {
260 			u8 keystream[SM4_BLOCK_SIZE];
261 
262 			sm4_crypt_block(ctx->rkey_enc, keystream, walk.iv);
263 			crypto_inc(walk.iv, SM4_BLOCK_SIZE);
264 			crypto_xor_cpy(dst, src, keystream, nbytes);
265 			nbytes = 0;
266 		}
267 
268 		err = skcipher_walk_done(&walk, nbytes);
269 	}
270 
271 	return err;
272 }
273 
274 static struct skcipher_alg sm4_algs[] = {
275 	{
276 		.base = {
277 			.cra_name		= "ecb(sm4)",
278 			.cra_driver_name	= "ecb-sm4-neon",
279 			.cra_priority		= 200,
280 			.cra_blocksize		= SM4_BLOCK_SIZE,
281 			.cra_ctxsize		= sizeof(struct sm4_ctx),
282 			.cra_module		= THIS_MODULE,
283 		},
284 		.min_keysize	= SM4_KEY_SIZE,
285 		.max_keysize	= SM4_KEY_SIZE,
286 		.setkey		= sm4_setkey,
287 		.encrypt	= sm4_ecb_encrypt,
288 		.decrypt	= sm4_ecb_decrypt,
289 	}, {
290 		.base = {
291 			.cra_name		= "cbc(sm4)",
292 			.cra_driver_name	= "cbc-sm4-neon",
293 			.cra_priority		= 200,
294 			.cra_blocksize		= SM4_BLOCK_SIZE,
295 			.cra_ctxsize		= sizeof(struct sm4_ctx),
296 			.cra_module		= THIS_MODULE,
297 		},
298 		.min_keysize	= SM4_KEY_SIZE,
299 		.max_keysize	= SM4_KEY_SIZE,
300 		.ivsize		= SM4_BLOCK_SIZE,
301 		.setkey		= sm4_setkey,
302 		.encrypt	= sm4_cbc_encrypt,
303 		.decrypt	= sm4_cbc_decrypt,
304 	}, {
305 		.base = {
306 			.cra_name		= "cfb(sm4)",
307 			.cra_driver_name	= "cfb-sm4-neon",
308 			.cra_priority		= 200,
309 			.cra_blocksize		= 1,
310 			.cra_ctxsize		= sizeof(struct sm4_ctx),
311 			.cra_module		= THIS_MODULE,
312 		},
313 		.min_keysize	= SM4_KEY_SIZE,
314 		.max_keysize	= SM4_KEY_SIZE,
315 		.ivsize		= SM4_BLOCK_SIZE,
316 		.chunksize	= SM4_BLOCK_SIZE,
317 		.setkey		= sm4_setkey,
318 		.encrypt	= sm4_cfb_encrypt,
319 		.decrypt	= sm4_cfb_decrypt,
320 	}, {
321 		.base = {
322 			.cra_name		= "ctr(sm4)",
323 			.cra_driver_name	= "ctr-sm4-neon",
324 			.cra_priority		= 200,
325 			.cra_blocksize		= 1,
326 			.cra_ctxsize		= sizeof(struct sm4_ctx),
327 			.cra_module		= THIS_MODULE,
328 		},
329 		.min_keysize	= SM4_KEY_SIZE,
330 		.max_keysize	= SM4_KEY_SIZE,
331 		.ivsize		= SM4_BLOCK_SIZE,
332 		.chunksize	= SM4_BLOCK_SIZE,
333 		.setkey		= sm4_setkey,
334 		.encrypt	= sm4_ctr_crypt,
335 		.decrypt	= sm4_ctr_crypt,
336 	}
337 };
338 
339 static int __init sm4_init(void)
340 {
341 	return crypto_register_skciphers(sm4_algs, ARRAY_SIZE(sm4_algs));
342 }
343 
344 static void __exit sm4_exit(void)
345 {
346 	crypto_unregister_skciphers(sm4_algs, ARRAY_SIZE(sm4_algs));
347 }
348 
349 module_init(sm4_init);
350 module_exit(sm4_exit);
351 
352 MODULE_DESCRIPTION("SM4 ECB/CBC/CFB/CTR using ARMv8 NEON");
353 MODULE_ALIAS_CRYPTO("sm4-neon");
354 MODULE_ALIAS_CRYPTO("sm4");
355 MODULE_ALIAS_CRYPTO("ecb(sm4)");
356 MODULE_ALIAS_CRYPTO("cbc(sm4)");
357 MODULE_ALIAS_CRYPTO("cfb(sm4)");
358 MODULE_ALIAS_CRYPTO("ctr(sm4)");
359 MODULE_AUTHOR("Tianjia Zhang <tianjia.zhang@linux.alibaba.com>");
360 MODULE_LICENSE("GPL v2");
361