tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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
19MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
20MODULE_LICENSE("GPL v2");
21
22MODULE_ALIAS_CRYPTO("ecb(aes)");
23MODULE_ALIAS_CRYPTO("cbc(aes)");
24MODULE_ALIAS_CRYPTO("ctr(aes)");
25MODULE_ALIAS_CRYPTO("xts(aes)");
26
27asmlinkage void aesbs_convert_key(u8 out[], u32 const rk[], int rounds);
28
29asmlinkage void aesbs_ecb_encrypt(u8 out[], u8 const in[], u8 const rk[],
30 int rounds, int blocks);
31asmlinkage void aesbs_ecb_decrypt(u8 out[], u8 const in[], u8 const rk[],
32 int rounds, int blocks);
33
34asmlinkage void aesbs_cbc_decrypt(u8 out[], u8 const in[], u8 const rk[],
35 int rounds, int blocks, u8 iv[]);
36
37asmlinkage void aesbs_ctr_encrypt(u8 out[], u8 const in[], u8 const rk[],
38 int rounds, int blocks, u8 ctr[], u8 final[]);
39
40asmlinkage void aesbs_xts_encrypt(u8 out[], u8 const in[], u8 const rk[],
41 int rounds, int blocks, u8 iv[]);
42asmlinkage void aesbs_xts_decrypt(u8 out[], u8 const in[], u8 const rk[],
43 int rounds, int blocks, u8 iv[]);
44
45struct aesbs_ctx {
46 int rounds;
47 u8 rk[13 * (8 * AES_BLOCK_SIZE) + 32] __aligned(AES_BLOCK_SIZE);
48};
49
50struct aesbs_cbc_ctx {
51 struct aesbs_ctx key;
52 struct crypto_cipher *enc_tfm;
53};
54
55struct aesbs_xts_ctx {
56 struct aesbs_ctx key;
57 struct crypto_cipher *tweak_tfm;
58};
59
60static 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
80static 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
109static int ecb_encrypt(struct skcipher_request *req)
110{
111 return __ecb_crypt(req, aesbs_ecb_encrypt);
112}
113
114static int ecb_decrypt(struct skcipher_request *req)
115{
116 return __ecb_crypt(req, aesbs_ecb_decrypt);
117}
118
119static 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
139static 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
146static int cbc_encrypt(struct skcipher_request *req)
147{
148 return crypto_cbc_encrypt_walk(req, cbc_encrypt_one);
149}
150
151static 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
179static 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
185 return PTR_ERR_OR_ZERO(ctx->enc_tfm);
186}
187
188static void cbc_exit(struct crypto_tfm *tfm)
189{
190 struct aesbs_cbc_ctx *ctx = crypto_tfm_ctx(tfm);
191
192 crypto_free_cipher(ctx->enc_tfm);
193}
194
195static int ctr_encrypt(struct skcipher_request *req)
196{
197 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
198 struct aesbs_ctx *ctx = crypto_skcipher_ctx(tfm);
199 struct skcipher_walk walk;
200 u8 buf[AES_BLOCK_SIZE];
201 int err;
202
203 err = skcipher_walk_virt(&walk, req, true);
204
205 kernel_neon_begin();
206 while (walk.nbytes > 0) {
207 unsigned int blocks = walk.nbytes / AES_BLOCK_SIZE;
208 u8 *final = (walk.total % AES_BLOCK_SIZE) ? buf : NULL;
209
210 if (walk.nbytes < walk.total) {
211 blocks = round_down(blocks,
212 walk.stride / AES_BLOCK_SIZE);
213 final = NULL;
214 }
215
216 aesbs_ctr_encrypt(walk.dst.virt.addr, walk.src.virt.addr,
217 ctx->rk, ctx->rounds, blocks, walk.iv, final);
218
219 if (final) {
220 u8 *dst = walk.dst.virt.addr + blocks * AES_BLOCK_SIZE;
221 u8 *src = walk.src.virt.addr + blocks * AES_BLOCK_SIZE;
222
223 crypto_xor_cpy(dst, src, final,
224 walk.total % AES_BLOCK_SIZE);
225
226 err = skcipher_walk_done(&walk, 0);
227 break;
228 }
229 err = skcipher_walk_done(&walk,
230 walk.nbytes - blocks * AES_BLOCK_SIZE);
231 }
232 kernel_neon_end();
233
234 return err;
235}
236
237static int aesbs_xts_setkey(struct crypto_skcipher *tfm, const u8 *in_key,
238 unsigned int key_len)
239{
240 struct aesbs_xts_ctx *ctx = crypto_skcipher_ctx(tfm);
241 int err;
242
243 err = xts_verify_key(tfm, in_key, key_len);
244 if (err)
245 return err;
246
247 key_len /= 2;
248 err = crypto_cipher_setkey(ctx->tweak_tfm, in_key + key_len, key_len);
249 if (err)
250 return err;
251
252 return aesbs_setkey(tfm, in_key, key_len);
253}
254
255static int xts_init(struct crypto_tfm *tfm)
256{
257 struct aesbs_xts_ctx *ctx = crypto_tfm_ctx(tfm);
258
259 ctx->tweak_tfm = crypto_alloc_cipher("aes", 0, 0);
260
261 return PTR_ERR_OR_ZERO(ctx->tweak_tfm);
262}
263
264static void xts_exit(struct crypto_tfm *tfm)
265{
266 struct aesbs_xts_ctx *ctx = crypto_tfm_ctx(tfm);
267
268 crypto_free_cipher(ctx->tweak_tfm);
269}
270
271static int __xts_crypt(struct skcipher_request *req,
272 void (*fn)(u8 out[], u8 const in[], u8 const rk[],
273 int rounds, int blocks, u8 iv[]))
274{
275 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
276 struct aesbs_xts_ctx *ctx = crypto_skcipher_ctx(tfm);
277 struct skcipher_walk walk;
278 int err;
279
280 err = skcipher_walk_virt(&walk, req, true);
281
282 crypto_cipher_encrypt_one(ctx->tweak_tfm, walk.iv, walk.iv);
283
284 kernel_neon_begin();
285 while (walk.nbytes >= AES_BLOCK_SIZE) {
286 unsigned int blocks = walk.nbytes / AES_BLOCK_SIZE;
287
288 if (walk.nbytes < walk.total)
289 blocks = round_down(blocks,
290 walk.stride / AES_BLOCK_SIZE);
291
292 fn(walk.dst.virt.addr, walk.src.virt.addr, ctx->key.rk,
293 ctx->key.rounds, blocks, walk.iv);
294 err = skcipher_walk_done(&walk,
295 walk.nbytes - blocks * AES_BLOCK_SIZE);
296 }
297 kernel_neon_end();
298
299 return err;
300}
301
302static int xts_encrypt(struct skcipher_request *req)
303{
304 return __xts_crypt(req, aesbs_xts_encrypt);
305}
306
307static int xts_decrypt(struct skcipher_request *req)
308{
309 return __xts_crypt(req, aesbs_xts_decrypt);
310}
311
312static struct skcipher_alg aes_algs[] = { {
313 .base.cra_name = "__ecb(aes)",
314 .base.cra_driver_name = "__ecb-aes-neonbs",
315 .base.cra_priority = 250,
316 .base.cra_blocksize = AES_BLOCK_SIZE,
317 .base.cra_ctxsize = sizeof(struct aesbs_ctx),
318 .base.cra_module = THIS_MODULE,
319 .base.cra_flags = CRYPTO_ALG_INTERNAL,
320
321 .min_keysize = AES_MIN_KEY_SIZE,
322 .max_keysize = AES_MAX_KEY_SIZE,
323 .walksize = 8 * AES_BLOCK_SIZE,
324 .setkey = aesbs_setkey,
325 .encrypt = ecb_encrypt,
326 .decrypt = ecb_decrypt,
327}, {
328 .base.cra_name = "__cbc(aes)",
329 .base.cra_driver_name = "__cbc-aes-neonbs",
330 .base.cra_priority = 250,
331 .base.cra_blocksize = AES_BLOCK_SIZE,
332 .base.cra_ctxsize = sizeof(struct aesbs_cbc_ctx),
333 .base.cra_module = THIS_MODULE,
334 .base.cra_flags = CRYPTO_ALG_INTERNAL,
335 .base.cra_init = cbc_init,
336 .base.cra_exit = cbc_exit,
337
338 .min_keysize = AES_MIN_KEY_SIZE,
339 .max_keysize = AES_MAX_KEY_SIZE,
340 .walksize = 8 * AES_BLOCK_SIZE,
341 .ivsize = AES_BLOCK_SIZE,
342 .setkey = aesbs_cbc_setkey,
343 .encrypt = cbc_encrypt,
344 .decrypt = cbc_decrypt,
345}, {
346 .base.cra_name = "__ctr(aes)",
347 .base.cra_driver_name = "__ctr-aes-neonbs",
348 .base.cra_priority = 250,
349 .base.cra_blocksize = 1,
350 .base.cra_ctxsize = sizeof(struct aesbs_ctx),
351 .base.cra_module = THIS_MODULE,
352 .base.cra_flags = CRYPTO_ALG_INTERNAL,
353
354 .min_keysize = AES_MIN_KEY_SIZE,
355 .max_keysize = AES_MAX_KEY_SIZE,
356 .chunksize = AES_BLOCK_SIZE,
357 .walksize = 8 * AES_BLOCK_SIZE,
358 .ivsize = AES_BLOCK_SIZE,
359 .setkey = aesbs_setkey,
360 .encrypt = ctr_encrypt,
361 .decrypt = ctr_encrypt,
362}, {
363 .base.cra_name = "__xts(aes)",
364 .base.cra_driver_name = "__xts-aes-neonbs",
365 .base.cra_priority = 250,
366 .base.cra_blocksize = AES_BLOCK_SIZE,
367 .base.cra_ctxsize = sizeof(struct aesbs_xts_ctx),
368 .base.cra_module = THIS_MODULE,
369 .base.cra_flags = CRYPTO_ALG_INTERNAL,
370 .base.cra_init = xts_init,
371 .base.cra_exit = xts_exit,
372
373 .min_keysize = 2 * AES_MIN_KEY_SIZE,
374 .max_keysize = 2 * AES_MAX_KEY_SIZE,
375 .walksize = 8 * AES_BLOCK_SIZE,
376 .ivsize = AES_BLOCK_SIZE,
377 .setkey = aesbs_xts_setkey,
378 .encrypt = xts_encrypt,
379 .decrypt = xts_decrypt,
380} };
381
382static struct simd_skcipher_alg *aes_simd_algs[ARRAY_SIZE(aes_algs)];
383
384static void aes_exit(void)
385{
386 int i;
387
388 for (i = 0; i < ARRAY_SIZE(aes_simd_algs); i++)
389 if (aes_simd_algs[i])
390 simd_skcipher_free(aes_simd_algs[i]);
391
392 crypto_unregister_skciphers(aes_algs, ARRAY_SIZE(aes_algs));
393}
394
395static int __init aes_init(void)
396{
397 struct simd_skcipher_alg *simd;
398 const char *basename;
399 const char *algname;
400 const char *drvname;
401 int err;
402 int i;
403
404 if (!(elf_hwcap & HWCAP_NEON))
405 return -ENODEV;
406
407 err = crypto_register_skciphers(aes_algs, ARRAY_SIZE(aes_algs));
408 if (err)
409 return err;
410
411 for (i = 0; i < ARRAY_SIZE(aes_algs); i++) {
412 if (!(aes_algs[i].base.cra_flags & CRYPTO_ALG_INTERNAL))
413 continue;
414
415 algname = aes_algs[i].base.cra_name + 2;
416 drvname = aes_algs[i].base.cra_driver_name + 2;
417 basename = aes_algs[i].base.cra_driver_name;
418 simd = simd_skcipher_create_compat(algname, drvname, basename);
419 err = PTR_ERR(simd);
420 if (IS_ERR(simd))
421 goto unregister_simds;
422
423 aes_simd_algs[i] = simd;
424 }
425 return 0;
426
427unregister_simds:
428 aes_exit();
429 return err;
430}
431
432late_initcall(aes_init);
433module_exit(aes_exit);