1 /*
2 * Bit sliced AES using NEON instructions
3 *
4 * Copyright (C) 2017 Linaro Ltd <ard.biesheuvel@linaro.org>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 */
10
11 #include <asm/neon.h>
12 #include <crypto/aes.h>
13 #include <crypto/cbc.h>
14 #include <crypto/internal/simd.h>
15 #include <crypto/internal/skcipher.h>
16 #include <crypto/xts.h>
17 #include <linux/module.h>
18
19 MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
20 MODULE_LICENSE("GPL v2");
21
22 MODULE_ALIAS_CRYPTO("ecb(aes)");
23 MODULE_ALIAS_CRYPTO("cbc(aes)");
24 MODULE_ALIAS_CRYPTO("ctr(aes)");
25 MODULE_ALIAS_CRYPTO("xts(aes)");
26
27 asmlinkage void aesbs_convert_key(u8 out[], u32 const rk[], int rounds);
28
29 asmlinkage void aesbs_ecb_encrypt(u8 out[], u8 const in[], u8 const rk[],
30 int rounds, int blocks);
31 asmlinkage void aesbs_ecb_decrypt(u8 out[], u8 const in[], u8 const rk[],
32 int rounds, int blocks);
33
34 asmlinkage void aesbs_cbc_decrypt(u8 out[], u8 const in[], u8 const rk[],
35 int rounds, int blocks, u8 iv[]);
36
37 asmlinkage void aesbs_ctr_encrypt(u8 out[], u8 const in[], u8 const rk[],
38 int rounds, int blocks, u8 ctr[], u8 final[]);
39
40 asmlinkage void aesbs_xts_encrypt(u8 out[], u8 const in[], u8 const rk[],
41 int rounds, int blocks, u8 iv[]);
42 asmlinkage void aesbs_xts_decrypt(u8 out[], u8 const in[], u8 const rk[],
43 int rounds, int blocks, u8 iv[]);
44
45 struct aesbs_ctx {
46 int rounds;
47 u8 rk[13 * (8 * AES_BLOCK_SIZE) + 32] __aligned(AES_BLOCK_SIZE);
48 };
49
50 struct aesbs_cbc_ctx {
51 struct aesbs_ctx key;
52 struct crypto_cipher *enc_tfm;
53 };
54
55 struct aesbs_xts_ctx {
56 struct aesbs_ctx key;
57 struct crypto_cipher *tweak_tfm;
58 };
59
aesbs_setkey(struct crypto_skcipher * tfm,const u8 * in_key,unsigned int key_len)60 static int aesbs_setkey(struct crypto_skcipher *tfm, const u8 *in_key,
61 unsigned int key_len)
62 {
63 struct aesbs_ctx *ctx = crypto_skcipher_ctx(tfm);
64 struct crypto_aes_ctx rk;
65 int err;
66
67 err = crypto_aes_expand_key(&rk, in_key, key_len);
68 if (err)
69 return err;
70
71 ctx->rounds = 6 + key_len / 4;
72
73 kernel_neon_begin();
74 aesbs_convert_key(ctx->rk, rk.key_enc, ctx->rounds);
75 kernel_neon_end();
76
77 return 0;
78 }
79
__ecb_crypt(struct skcipher_request * req,void (* fn)(u8 out[],u8 const in[],u8 const rk[],int rounds,int blocks))80 static int __ecb_crypt(struct skcipher_request *req,
81 void (*fn)(u8 out[], u8 const in[], u8 const rk[],
82 int rounds, int blocks))
83 {
84 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
85 struct aesbs_ctx *ctx = crypto_skcipher_ctx(tfm);
86 struct skcipher_walk walk;
87 int err;
88
89 err = skcipher_walk_virt(&walk, req, true);
90
91 kernel_neon_begin();
92 while (walk.nbytes >= AES_BLOCK_SIZE) {
93 unsigned int blocks = walk.nbytes / AES_BLOCK_SIZE;
94
95 if (walk.nbytes < walk.total)
96 blocks = round_down(blocks,
97 walk.stride / AES_BLOCK_SIZE);
98
99 fn(walk.dst.virt.addr, walk.src.virt.addr, ctx->rk,
100 ctx->rounds, blocks);
101 err = skcipher_walk_done(&walk,
102 walk.nbytes - blocks * AES_BLOCK_SIZE);
103 }
104 kernel_neon_end();
105
106 return err;
107 }
108
ecb_encrypt(struct skcipher_request * req)109 static int ecb_encrypt(struct skcipher_request *req)
110 {
111 return __ecb_crypt(req, aesbs_ecb_encrypt);
112 }
113
ecb_decrypt(struct skcipher_request * req)114 static int ecb_decrypt(struct skcipher_request *req)
115 {
116 return __ecb_crypt(req, aesbs_ecb_decrypt);
117 }
118
aesbs_cbc_setkey(struct crypto_skcipher * tfm,const u8 * in_key,unsigned int key_len)119 static int aesbs_cbc_setkey(struct crypto_skcipher *tfm, const u8 *in_key,
120 unsigned int key_len)
121 {
122 struct aesbs_cbc_ctx *ctx = crypto_skcipher_ctx(tfm);
123 struct crypto_aes_ctx rk;
124 int err;
125
126 err = crypto_aes_expand_key(&rk, in_key, key_len);
127 if (err)
128 return err;
129
130 ctx->key.rounds = 6 + key_len / 4;
131
132 kernel_neon_begin();
133 aesbs_convert_key(ctx->key.rk, rk.key_enc, ctx->key.rounds);
134 kernel_neon_end();
135
136 return crypto_cipher_setkey(ctx->enc_tfm, in_key, key_len);
137 }
138
cbc_encrypt_one(struct crypto_skcipher * tfm,const u8 * src,u8 * dst)139 static void cbc_encrypt_one(struct crypto_skcipher *tfm, const u8 *src, u8 *dst)
140 {
141 struct aesbs_cbc_ctx *ctx = crypto_skcipher_ctx(tfm);
142
143 crypto_cipher_encrypt_one(ctx->enc_tfm, dst, src);
144 }
145
cbc_encrypt(struct skcipher_request * req)146 static int cbc_encrypt(struct skcipher_request *req)
147 {
148 return crypto_cbc_encrypt_walk(req, cbc_encrypt_one);
149 }
150
cbc_decrypt(struct skcipher_request * req)151 static int cbc_decrypt(struct skcipher_request *req)
152 {
153 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
154 struct aesbs_cbc_ctx *ctx = crypto_skcipher_ctx(tfm);
155 struct skcipher_walk walk;
156 int err;
157
158 err = skcipher_walk_virt(&walk, req, true);
159
160 kernel_neon_begin();
161 while (walk.nbytes >= AES_BLOCK_SIZE) {
162 unsigned int blocks = walk.nbytes / AES_BLOCK_SIZE;
163
164 if (walk.nbytes < walk.total)
165 blocks = round_down(blocks,
166 walk.stride / AES_BLOCK_SIZE);
167
168 aesbs_cbc_decrypt(walk.dst.virt.addr, walk.src.virt.addr,
169 ctx->key.rk, ctx->key.rounds, blocks,
170 walk.iv);
171 err = skcipher_walk_done(&walk,
172 walk.nbytes - blocks * AES_BLOCK_SIZE);
173 }
174 kernel_neon_end();
175
176 return err;
177 }
178
cbc_init(struct crypto_tfm * tfm)179 static int cbc_init(struct crypto_tfm *tfm)
180 {
181 struct aesbs_cbc_ctx *ctx = crypto_tfm_ctx(tfm);
182
183 ctx->enc_tfm = crypto_alloc_cipher("aes", 0, 0);
184 if (IS_ERR(ctx->enc_tfm))
185 return PTR_ERR(ctx->enc_tfm);
186 return 0;
187 }
188
cbc_exit(struct crypto_tfm * tfm)189 static void cbc_exit(struct crypto_tfm *tfm)
190 {
191 struct aesbs_cbc_ctx *ctx = crypto_tfm_ctx(tfm);
192
193 crypto_free_cipher(ctx->enc_tfm);
194 }
195
ctr_encrypt(struct skcipher_request * req)196 static int ctr_encrypt(struct skcipher_request *req)
197 {
198 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
199 struct aesbs_ctx *ctx = crypto_skcipher_ctx(tfm);
200 struct skcipher_walk walk;
201 u8 buf[AES_BLOCK_SIZE];
202 int err;
203
204 err = skcipher_walk_virt(&walk, req, true);
205
206 kernel_neon_begin();
207 while (walk.nbytes > 0) {
208 unsigned int blocks = walk.nbytes / AES_BLOCK_SIZE;
209 u8 *final = (walk.total % AES_BLOCK_SIZE) ? buf : NULL;
210
211 if (walk.nbytes < walk.total) {
212 blocks = round_down(blocks,
213 walk.stride / AES_BLOCK_SIZE);
214 final = NULL;
215 }
216
217 aesbs_ctr_encrypt(walk.dst.virt.addr, walk.src.virt.addr,
218 ctx->rk, ctx->rounds, blocks, walk.iv, final);
219
220 if (final) {
221 u8 *dst = walk.dst.virt.addr + blocks * AES_BLOCK_SIZE;
222 u8 *src = walk.src.virt.addr + blocks * AES_BLOCK_SIZE;
223
224 crypto_xor_cpy(dst, src, final,
225 walk.total % AES_BLOCK_SIZE);
226
227 err = skcipher_walk_done(&walk, 0);
228 break;
229 }
230 err = skcipher_walk_done(&walk,
231 walk.nbytes - blocks * AES_BLOCK_SIZE);
232 }
233 kernel_neon_end();
234
235 return err;
236 }
237
aesbs_xts_setkey(struct crypto_skcipher * tfm,const u8 * in_key,unsigned int key_len)238 static int aesbs_xts_setkey(struct crypto_skcipher *tfm, const u8 *in_key,
239 unsigned int key_len)
240 {
241 struct aesbs_xts_ctx *ctx = crypto_skcipher_ctx(tfm);
242 int err;
243
244 err = xts_verify_key(tfm, in_key, key_len);
245 if (err)
246 return err;
247
248 key_len /= 2;
249 err = crypto_cipher_setkey(ctx->tweak_tfm, in_key + key_len, key_len);
250 if (err)
251 return err;
252
253 return aesbs_setkey(tfm, in_key, key_len);
254 }
255
xts_init(struct crypto_tfm * tfm)256 static int xts_init(struct crypto_tfm *tfm)
257 {
258 struct aesbs_xts_ctx *ctx = crypto_tfm_ctx(tfm);
259
260 ctx->tweak_tfm = crypto_alloc_cipher("aes", 0, 0);
261 if (IS_ERR(ctx->tweak_tfm))
262 return PTR_ERR(ctx->tweak_tfm);
263 return 0;
264 }
265
xts_exit(struct crypto_tfm * tfm)266 static void xts_exit(struct crypto_tfm *tfm)
267 {
268 struct aesbs_xts_ctx *ctx = crypto_tfm_ctx(tfm);
269
270 crypto_free_cipher(ctx->tweak_tfm);
271 }
272
__xts_crypt(struct skcipher_request * req,void (* fn)(u8 out[],u8 const in[],u8 const rk[],int rounds,int blocks,u8 iv[]))273 static int __xts_crypt(struct skcipher_request *req,
274 void (*fn)(u8 out[], u8 const in[], u8 const rk[],
275 int rounds, int blocks, u8 iv[]))
276 {
277 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
278 struct aesbs_xts_ctx *ctx = crypto_skcipher_ctx(tfm);
279 struct skcipher_walk walk;
280 int err;
281
282 err = skcipher_walk_virt(&walk, req, true);
283 if (err)
284 return err;
285
286 crypto_cipher_encrypt_one(ctx->tweak_tfm, walk.iv, walk.iv);
287
288 kernel_neon_begin();
289 while (walk.nbytes >= AES_BLOCK_SIZE) {
290 unsigned int blocks = walk.nbytes / AES_BLOCK_SIZE;
291
292 if (walk.nbytes < walk.total)
293 blocks = round_down(blocks,
294 walk.stride / AES_BLOCK_SIZE);
295
296 fn(walk.dst.virt.addr, walk.src.virt.addr, ctx->key.rk,
297 ctx->key.rounds, blocks, walk.iv);
298 err = skcipher_walk_done(&walk,
299 walk.nbytes - blocks * AES_BLOCK_SIZE);
300 }
301 kernel_neon_end();
302
303 return err;
304 }
305
xts_encrypt(struct skcipher_request * req)306 static int xts_encrypt(struct skcipher_request *req)
307 {
308 return __xts_crypt(req, aesbs_xts_encrypt);
309 }
310
xts_decrypt(struct skcipher_request * req)311 static int xts_decrypt(struct skcipher_request *req)
312 {
313 return __xts_crypt(req, aesbs_xts_decrypt);
314 }
315
316 static struct skcipher_alg aes_algs[] = { {
317 .base.cra_name = "__ecb(aes)",
318 .base.cra_driver_name = "__ecb-aes-neonbs",
319 .base.cra_priority = 250,
320 .base.cra_blocksize = AES_BLOCK_SIZE,
321 .base.cra_ctxsize = sizeof(struct aesbs_ctx),
322 .base.cra_module = THIS_MODULE,
323 .base.cra_flags = CRYPTO_ALG_INTERNAL,
324
325 .min_keysize = AES_MIN_KEY_SIZE,
326 .max_keysize = AES_MAX_KEY_SIZE,
327 .walksize = 8 * AES_BLOCK_SIZE,
328 .setkey = aesbs_setkey,
329 .encrypt = ecb_encrypt,
330 .decrypt = ecb_decrypt,
331 }, {
332 .base.cra_name = "__cbc(aes)",
333 .base.cra_driver_name = "__cbc-aes-neonbs",
334 .base.cra_priority = 250,
335 .base.cra_blocksize = AES_BLOCK_SIZE,
336 .base.cra_ctxsize = sizeof(struct aesbs_cbc_ctx),
337 .base.cra_module = THIS_MODULE,
338 .base.cra_flags = CRYPTO_ALG_INTERNAL,
339 .base.cra_init = cbc_init,
340 .base.cra_exit = cbc_exit,
341
342 .min_keysize = AES_MIN_KEY_SIZE,
343 .max_keysize = AES_MAX_KEY_SIZE,
344 .walksize = 8 * AES_BLOCK_SIZE,
345 .ivsize = AES_BLOCK_SIZE,
346 .setkey = aesbs_cbc_setkey,
347 .encrypt = cbc_encrypt,
348 .decrypt = cbc_decrypt,
349 }, {
350 .base.cra_name = "__ctr(aes)",
351 .base.cra_driver_name = "__ctr-aes-neonbs",
352 .base.cra_priority = 250,
353 .base.cra_blocksize = 1,
354 .base.cra_ctxsize = sizeof(struct aesbs_ctx),
355 .base.cra_module = THIS_MODULE,
356 .base.cra_flags = CRYPTO_ALG_INTERNAL,
357
358 .min_keysize = AES_MIN_KEY_SIZE,
359 .max_keysize = AES_MAX_KEY_SIZE,
360 .chunksize = AES_BLOCK_SIZE,
361 .walksize = 8 * AES_BLOCK_SIZE,
362 .ivsize = AES_BLOCK_SIZE,
363 .setkey = aesbs_setkey,
364 .encrypt = ctr_encrypt,
365 .decrypt = ctr_encrypt,
366 }, {
367 .base.cra_name = "__xts(aes)",
368 .base.cra_driver_name = "__xts-aes-neonbs",
369 .base.cra_priority = 250,
370 .base.cra_blocksize = AES_BLOCK_SIZE,
371 .base.cra_ctxsize = sizeof(struct aesbs_xts_ctx),
372 .base.cra_module = THIS_MODULE,
373 .base.cra_flags = CRYPTO_ALG_INTERNAL,
374 .base.cra_init = xts_init,
375 .base.cra_exit = xts_exit,
376
377 .min_keysize = 2 * AES_MIN_KEY_SIZE,
378 .max_keysize = 2 * AES_MAX_KEY_SIZE,
379 .walksize = 8 * AES_BLOCK_SIZE,
380 .ivsize = AES_BLOCK_SIZE,
381 .setkey = aesbs_xts_setkey,
382 .encrypt = xts_encrypt,
383 .decrypt = xts_decrypt,
384 } };
385
386 static struct simd_skcipher_alg *aes_simd_algs[ARRAY_SIZE(aes_algs)];
387
aes_exit(void)388 static void aes_exit(void)
389 {
390 int i;
391
392 for (i = 0; i < ARRAY_SIZE(aes_simd_algs); i++)
393 if (aes_simd_algs[i])
394 simd_skcipher_free(aes_simd_algs[i]);
395
396 crypto_unregister_skciphers(aes_algs, ARRAY_SIZE(aes_algs));
397 }
398
aes_init(void)399 static int __init aes_init(void)
400 {
401 struct simd_skcipher_alg *simd;
402 const char *basename;
403 const char *algname;
404 const char *drvname;
405 int err;
406 int i;
407
408 if (!(elf_hwcap & HWCAP_NEON))
409 return -ENODEV;
410
411 err = crypto_register_skciphers(aes_algs, ARRAY_SIZE(aes_algs));
412 if (err)
413 return err;
414
415 for (i = 0; i < ARRAY_SIZE(aes_algs); i++) {
416 if (!(aes_algs[i].base.cra_flags & CRYPTO_ALG_INTERNAL))
417 continue;
418
419 algname = aes_algs[i].base.cra_name + 2;
420 drvname = aes_algs[i].base.cra_driver_name + 2;
421 basename = aes_algs[i].base.cra_driver_name;
422 simd = simd_skcipher_create_compat(algname, drvname, basename);
423 err = PTR_ERR(simd);
424 if (IS_ERR(simd))
425 goto unregister_simds;
426
427 aes_simd_algs[i] = simd;
428 }
429 return 0;
430
431 unregister_simds:
432 aes_exit();
433 return err;
434 }
435
436 late_initcall(aes_init);
437 module_exit(aes_exit);
438