1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Linear symmetric key cipher operations.
4 *
5 * Generic encrypt/decrypt wrapper for ciphers.
6 *
7 * Copyright (c) 2023 Herbert Xu <herbert@gondor.apana.org.au>
8 */
9
10 #include <linux/cryptouser.h>
11 #include <linux/err.h>
12 #include <linux/export.h>
13 #include <linux/kernel.h>
14 #include <linux/seq_file.h>
15 #include <linux/slab.h>
16 #include <linux/string.h>
17 #include <net/netlink.h>
18 #include "skcipher.h"
19
20 static inline struct crypto_lskcipher *__crypto_lskcipher_cast(
21 struct crypto_tfm *tfm)
22 {
23 return container_of(tfm, struct crypto_lskcipher, base);
24 }
25
26 static inline struct lskcipher_alg *__crypto_lskcipher_alg(
27 struct crypto_alg *alg)
28 {
29 return container_of(alg, struct lskcipher_alg, co.base);
30 }
31
32 static int lskcipher_setkey_unaligned(struct crypto_lskcipher *tfm,
33 const u8 *key, unsigned int keylen)
34 {
35 unsigned long alignmask = crypto_lskcipher_alignmask(tfm);
36 struct lskcipher_alg *cipher = crypto_lskcipher_alg(tfm);
37 u8 *buffer, *alignbuffer;
38 unsigned long absize;
39 int ret;
40
41 absize = keylen + alignmask;
42 buffer = kmalloc(absize, GFP_ATOMIC);
43 if (!buffer)
44 return -ENOMEM;
45
46 alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
47 memcpy(alignbuffer, key, keylen);
48 ret = cipher->setkey(tfm, alignbuffer, keylen);
49 kfree_sensitive(buffer);
50 return ret;
51 }
52
53 int crypto_lskcipher_setkey(struct crypto_lskcipher *tfm, const u8 *key,
54 unsigned int keylen)
55 {
56 unsigned long alignmask = crypto_lskcipher_alignmask(tfm);
57 struct lskcipher_alg *cipher = crypto_lskcipher_alg(tfm);
58
59 if (keylen < cipher->co.min_keysize || keylen > cipher->co.max_keysize)
60 return -EINVAL;
61
62 if ((unsigned long)key & alignmask)
63 return lskcipher_setkey_unaligned(tfm, key, keylen);
64 else
65 return cipher->setkey(tfm, key, keylen);
66 }
67 EXPORT_SYMBOL_GPL(crypto_lskcipher_setkey);
68
69 static int crypto_lskcipher_crypt_unaligned(
70 struct crypto_lskcipher *tfm, const u8 *src, u8 *dst, unsigned len,
71 u8 *iv, int (*crypt)(struct crypto_lskcipher *tfm, const u8 *src,
72 u8 *dst, unsigned len, u8 *iv, u32 flags))
73 {
74 unsigned statesize = crypto_lskcipher_statesize(tfm);
75 unsigned ivsize = crypto_lskcipher_ivsize(tfm);
76 unsigned bs = crypto_lskcipher_blocksize(tfm);
77 unsigned cs = crypto_lskcipher_chunksize(tfm);
78 int err;
79 u8 *tiv;
80 u8 *p;
81
82 BUILD_BUG_ON(MAX_CIPHER_BLOCKSIZE > PAGE_SIZE ||
83 MAX_CIPHER_ALIGNMASK >= PAGE_SIZE);
84
85 tiv = kmalloc(PAGE_SIZE, GFP_ATOMIC);
86 if (!tiv)
87 return -ENOMEM;
88
89 memcpy(tiv, iv, ivsize + statesize);
90
91 p = kmalloc(PAGE_SIZE, GFP_ATOMIC);
92 err = -ENOMEM;
93 if (!p)
94 goto out;
95
96 while (len >= bs) {
97 unsigned chunk = min((unsigned)PAGE_SIZE, len);
98 int err;
99
100 if (chunk > cs)
101 chunk &= ~(cs - 1);
102
103 memcpy(p, src, chunk);
104 err = crypt(tfm, p, p, chunk, tiv, CRYPTO_LSKCIPHER_FLAG_FINAL);
105 if (err)
106 goto out;
107
108 memcpy(dst, p, chunk);
109 src += chunk;
110 dst += chunk;
111 len -= chunk;
112 }
113
114 err = len ? -EINVAL : 0;
115
116 out:
117 memcpy(iv, tiv, ivsize + statesize);
118 kfree_sensitive(p);
119 kfree_sensitive(tiv);
120 return err;
121 }
122
123 static int crypto_lskcipher_crypt(struct crypto_lskcipher *tfm, const u8 *src,
124 u8 *dst, unsigned len, u8 *iv,
125 int (*crypt)(struct crypto_lskcipher *tfm,
126 const u8 *src, u8 *dst,
127 unsigned len, u8 *iv,
128 u32 flags))
129 {
130 unsigned long alignmask = crypto_lskcipher_alignmask(tfm);
131
132 if (((unsigned long)src | (unsigned long)dst | (unsigned long)iv) &
133 alignmask)
134 return crypto_lskcipher_crypt_unaligned(tfm, src, dst, len, iv,
135 crypt);
136
137 return crypt(tfm, src, dst, len, iv, CRYPTO_LSKCIPHER_FLAG_FINAL);
138 }
139
140 int crypto_lskcipher_encrypt(struct crypto_lskcipher *tfm, const u8 *src,
141 u8 *dst, unsigned len, u8 *iv)
142 {
143 struct lskcipher_alg *alg = crypto_lskcipher_alg(tfm);
144
145 return crypto_lskcipher_crypt(tfm, src, dst, len, iv, alg->encrypt);
146 }
147 EXPORT_SYMBOL_GPL(crypto_lskcipher_encrypt);
148
149 int crypto_lskcipher_decrypt(struct crypto_lskcipher *tfm, const u8 *src,
150 u8 *dst, unsigned len, u8 *iv)
151 {
152 struct lskcipher_alg *alg = crypto_lskcipher_alg(tfm);
153
154 return crypto_lskcipher_crypt(tfm, src, dst, len, iv, alg->decrypt);
155 }
156 EXPORT_SYMBOL_GPL(crypto_lskcipher_decrypt);
157
158 static int crypto_lskcipher_crypt_sg(struct skcipher_request *req,
159 int (*crypt)(struct crypto_lskcipher *tfm,
160 const u8 *src, u8 *dst,
161 unsigned len, u8 *ivs,
162 u32 flags))
163 {
164 struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req);
165 struct crypto_lskcipher **ctx = crypto_skcipher_ctx(skcipher);
166 u8 *ivs = skcipher_request_ctx(req);
167 struct crypto_lskcipher *tfm = *ctx;
168 struct skcipher_walk walk;
169 unsigned ivsize;
170 u32 flags;
171 int err;
172
173 ivsize = crypto_lskcipher_ivsize(tfm);
174 ivs = PTR_ALIGN(ivs, crypto_skcipher_alignmask(skcipher) + 1);
175 memcpy(ivs, req->iv, ivsize);
176
177 flags = req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP;
178
179 if (req->base.flags & CRYPTO_SKCIPHER_REQ_CONT)
180 flags |= CRYPTO_LSKCIPHER_FLAG_CONT;
181
182 if (!(req->base.flags & CRYPTO_SKCIPHER_REQ_NOTFINAL))
183 flags |= CRYPTO_LSKCIPHER_FLAG_FINAL;
184
185 err = skcipher_walk_virt(&walk, req, false);
186
187 while (walk.nbytes) {
188 err = crypt(tfm, walk.src.virt.addr, walk.dst.virt.addr,
189 walk.nbytes, ivs,
190 flags & ~(walk.nbytes == walk.total ?
191 0 : CRYPTO_LSKCIPHER_FLAG_FINAL));
192 err = skcipher_walk_done(&walk, err);
193 flags |= CRYPTO_LSKCIPHER_FLAG_CONT;
194 }
195
196 memcpy(req->iv, ivs, ivsize);
197
198 return err;
199 }
200
201 int crypto_lskcipher_encrypt_sg(struct skcipher_request *req)
202 {
203 struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req);
204 struct crypto_lskcipher **ctx = crypto_skcipher_ctx(skcipher);
205 struct lskcipher_alg *alg = crypto_lskcipher_alg(*ctx);
206
207 return crypto_lskcipher_crypt_sg(req, alg->encrypt);
208 }
209
210 int crypto_lskcipher_decrypt_sg(struct skcipher_request *req)
211 {
212 struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req);
213 struct crypto_lskcipher **ctx = crypto_skcipher_ctx(skcipher);
214 struct lskcipher_alg *alg = crypto_lskcipher_alg(*ctx);
215
216 return crypto_lskcipher_crypt_sg(req, alg->decrypt);
217 }
218
219 static void crypto_lskcipher_exit_tfm(struct crypto_tfm *tfm)
220 {
221 struct crypto_lskcipher *skcipher = __crypto_lskcipher_cast(tfm);
222 struct lskcipher_alg *alg = crypto_lskcipher_alg(skcipher);
223
224 alg->exit(skcipher);
225 }
226
227 static int crypto_lskcipher_init_tfm(struct crypto_tfm *tfm)
228 {
229 struct crypto_lskcipher *skcipher = __crypto_lskcipher_cast(tfm);
230 struct lskcipher_alg *alg = crypto_lskcipher_alg(skcipher);
231
232 if (alg->exit)
233 skcipher->base.exit = crypto_lskcipher_exit_tfm;
234
235 if (alg->init)
236 return alg->init(skcipher);
237
238 return 0;
239 }
240
241 static void crypto_lskcipher_free_instance(struct crypto_instance *inst)
242 {
243 struct lskcipher_instance *skcipher =
244 container_of(inst, struct lskcipher_instance, s.base);
245
246 skcipher->free(skcipher);
247 }
248
249 static void __maybe_unused crypto_lskcipher_show(
250 struct seq_file *m, struct crypto_alg *alg)
251 {
252 struct lskcipher_alg *skcipher = __crypto_lskcipher_alg(alg);
253
254 seq_printf(m, "type : lskcipher\n");
255 seq_printf(m, "blocksize : %u\n", alg->cra_blocksize);
256 seq_printf(m, "min keysize : %u\n", skcipher->co.min_keysize);
257 seq_printf(m, "max keysize : %u\n", skcipher->co.max_keysize);
258 seq_printf(m, "ivsize : %u\n", skcipher->co.ivsize);
259 seq_printf(m, "chunksize : %u\n", skcipher->co.chunksize);
260 seq_printf(m, "statesize : %u\n", skcipher->co.statesize);
261 }
262
263 static int __maybe_unused crypto_lskcipher_report(
264 struct sk_buff *skb, struct crypto_alg *alg)
265 {
266 struct lskcipher_alg *skcipher = __crypto_lskcipher_alg(alg);
267 struct crypto_report_blkcipher rblkcipher;
268
269 memset(&rblkcipher, 0, sizeof(rblkcipher));
270
271 strscpy(rblkcipher.type, "lskcipher", sizeof(rblkcipher.type));
272 strscpy(rblkcipher.geniv, "<none>", sizeof(rblkcipher.geniv));
273
274 rblkcipher.blocksize = alg->cra_blocksize;
275 rblkcipher.min_keysize = skcipher->co.min_keysize;
276 rblkcipher.max_keysize = skcipher->co.max_keysize;
277 rblkcipher.ivsize = skcipher->co.ivsize;
278
279 return nla_put(skb, CRYPTOCFGA_REPORT_BLKCIPHER,
280 sizeof(rblkcipher), &rblkcipher);
281 }
282
283 static const struct crypto_type crypto_lskcipher_type = {
284 .extsize = crypto_alg_extsize,
285 .init_tfm = crypto_lskcipher_init_tfm,
286 .free = crypto_lskcipher_free_instance,
287 #ifdef CONFIG_PROC_FS
288 .show = crypto_lskcipher_show,
289 #endif
290 #if IS_ENABLED(CONFIG_CRYPTO_USER)
291 .report = crypto_lskcipher_report,
292 #endif
293 .maskclear = ~CRYPTO_ALG_TYPE_MASK,
294 .maskset = CRYPTO_ALG_TYPE_MASK,
295 .type = CRYPTO_ALG_TYPE_LSKCIPHER,
296 .tfmsize = offsetof(struct crypto_lskcipher, base),
297 };
298
299 static void crypto_lskcipher_exit_tfm_sg(struct crypto_tfm *tfm)
300 {
301 struct crypto_lskcipher **ctx = crypto_tfm_ctx(tfm);
302
303 crypto_free_lskcipher(*ctx);
304 }
305
306 int crypto_init_lskcipher_ops_sg(struct crypto_tfm *tfm)
307 {
308 struct crypto_lskcipher **ctx = crypto_tfm_ctx(tfm);
309 struct crypto_alg *calg = tfm->__crt_alg;
310 struct crypto_lskcipher *skcipher;
311
312 if (!crypto_mod_get(calg))
313 return -EAGAIN;
314
315 skcipher = crypto_create_tfm(calg, &crypto_lskcipher_type);
316 if (IS_ERR(skcipher)) {
317 crypto_mod_put(calg);
318 return PTR_ERR(skcipher);
319 }
320
321 *ctx = skcipher;
322 tfm->exit = crypto_lskcipher_exit_tfm_sg;
323
324 return 0;
325 }
326
327 int crypto_grab_lskcipher(struct crypto_lskcipher_spawn *spawn,
328 struct crypto_instance *inst,
329 const char *name, u32 type, u32 mask)
330 {
331 spawn->base.frontend = &crypto_lskcipher_type;
332 return crypto_grab_spawn(&spawn->base, inst, name, type, mask);
333 }
334 EXPORT_SYMBOL_GPL(crypto_grab_lskcipher);
335
336 struct crypto_lskcipher *crypto_alloc_lskcipher(const char *alg_name,
337 u32 type, u32 mask)
338 {
339 return crypto_alloc_tfm(alg_name, &crypto_lskcipher_type, type, mask);
340 }
341 EXPORT_SYMBOL_GPL(crypto_alloc_lskcipher);
342
343 static int lskcipher_prepare_alg(struct lskcipher_alg *alg)
344 {
345 struct crypto_alg *base = &alg->co.base;
346 int err;
347
348 err = skcipher_prepare_alg_common(&alg->co);
349 if (err)
350 return err;
351
352 if (alg->co.chunksize & (alg->co.chunksize - 1))
353 return -EINVAL;
354
355 base->cra_type = &crypto_lskcipher_type;
356 base->cra_flags |= CRYPTO_ALG_TYPE_LSKCIPHER;
357
358 return 0;
359 }
360
361 int crypto_register_lskcipher(struct lskcipher_alg *alg)
362 {
363 struct crypto_alg *base = &alg->co.base;
364 int err;
365
366 err = lskcipher_prepare_alg(alg);
367 if (err)
368 return err;
369
370 return crypto_register_alg(base);
371 }
372 EXPORT_SYMBOL_GPL(crypto_register_lskcipher);
373
374 void crypto_unregister_lskcipher(struct lskcipher_alg *alg)
375 {
376 crypto_unregister_alg(&alg->co.base);
377 }
378 EXPORT_SYMBOL_GPL(crypto_unregister_lskcipher);
379
380 int crypto_register_lskciphers(struct lskcipher_alg *algs, int count)
381 {
382 int i, ret;
383
384 for (i = 0; i < count; i++) {
385 ret = crypto_register_lskcipher(&algs[i]);
386 if (ret)
387 goto err;
388 }
389
390 return 0;
391
392 err:
393 for (--i; i >= 0; --i)
394 crypto_unregister_lskcipher(&algs[i]);
395
396 return ret;
397 }
398 EXPORT_SYMBOL_GPL(crypto_register_lskciphers);
399
400 void crypto_unregister_lskciphers(struct lskcipher_alg *algs, int count)
401 {
402 int i;
403
404 for (i = count - 1; i >= 0; --i)
405 crypto_unregister_lskcipher(&algs[i]);
406 }
407 EXPORT_SYMBOL_GPL(crypto_unregister_lskciphers);
408
409 int lskcipher_register_instance(struct crypto_template *tmpl,
410 struct lskcipher_instance *inst)
411 {
412 int err;
413
414 if (WARN_ON(!inst->free))
415 return -EINVAL;
416
417 err = lskcipher_prepare_alg(&inst->alg);
418 if (err)
419 return err;
420
421 return crypto_register_instance(tmpl, lskcipher_crypto_instance(inst));
422 }
423 EXPORT_SYMBOL_GPL(lskcipher_register_instance);
424
425 static int lskcipher_setkey_simple(struct crypto_lskcipher *tfm, const u8 *key,
426 unsigned int keylen)
427 {
428 struct crypto_lskcipher *cipher = lskcipher_cipher_simple(tfm);
429
430 crypto_lskcipher_clear_flags(cipher, CRYPTO_TFM_REQ_MASK);
431 crypto_lskcipher_set_flags(cipher, crypto_lskcipher_get_flags(tfm) &
432 CRYPTO_TFM_REQ_MASK);
433 return crypto_lskcipher_setkey(cipher, key, keylen);
434 }
435
436 static int lskcipher_init_tfm_simple(struct crypto_lskcipher *tfm)
437 {
438 struct lskcipher_instance *inst = lskcipher_alg_instance(tfm);
439 struct crypto_lskcipher **ctx = crypto_lskcipher_ctx(tfm);
440 struct crypto_lskcipher_spawn *spawn;
441 struct crypto_lskcipher *cipher;
442
443 spawn = lskcipher_instance_ctx(inst);
444 cipher = crypto_spawn_lskcipher(spawn);
445 if (IS_ERR(cipher))
446 return PTR_ERR(cipher);
447
448 *ctx = cipher;
449 return 0;
450 }
451
452 static void lskcipher_exit_tfm_simple(struct crypto_lskcipher *tfm)
453 {
454 struct crypto_lskcipher **ctx = crypto_lskcipher_ctx(tfm);
455
456 crypto_free_lskcipher(*ctx);
457 }
458
459 static void lskcipher_free_instance_simple(struct lskcipher_instance *inst)
460 {
461 crypto_drop_lskcipher(lskcipher_instance_ctx(inst));
462 kfree(inst);
463 }
464
465 /**
466 * lskcipher_alloc_instance_simple - allocate instance of simple block cipher
467 *
468 * Allocate an lskcipher_instance for a simple block cipher mode of operation,
469 * e.g. cbc or ecb. The instance context will have just a single crypto_spawn,
470 * that for the underlying cipher. The {min,max}_keysize, ivsize, blocksize,
471 * alignmask, and priority are set from the underlying cipher but can be
472 * overridden if needed. The tfm context defaults to
473 * struct crypto_lskcipher *, and default ->setkey(), ->init(), and
474 * ->exit() methods are installed.
475 *
476 * @tmpl: the template being instantiated
477 * @tb: the template parameters
478 *
479 * Return: a pointer to the new instance, or an ERR_PTR(). The caller still
480 * needs to register the instance.
481 */
482 struct lskcipher_instance *lskcipher_alloc_instance_simple(
483 struct crypto_template *tmpl, struct rtattr **tb)
484 {
485 u32 mask;
486 struct lskcipher_instance *inst;
487 struct crypto_lskcipher_spawn *spawn;
488 char ecb_name[CRYPTO_MAX_ALG_NAME];
489 struct lskcipher_alg *cipher_alg;
490 const char *cipher_name;
491 int err;
492
493 err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_LSKCIPHER, &mask);
494 if (err)
495 return ERR_PTR(err);
496
497 cipher_name = crypto_attr_alg_name(tb[1]);
498 if (IS_ERR(cipher_name))
499 return ERR_CAST(cipher_name);
500
501 inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
502 if (!inst)
503 return ERR_PTR(-ENOMEM);
504
505 spawn = lskcipher_instance_ctx(inst);
506 err = crypto_grab_lskcipher(spawn,
507 lskcipher_crypto_instance(inst),
508 cipher_name, 0, mask);
509
510 ecb_name[0] = 0;
511 if (err == -ENOENT && !!memcmp(tmpl->name, "ecb", 4)) {
512 err = -ENAMETOOLONG;
513 if (snprintf(ecb_name, CRYPTO_MAX_ALG_NAME, "ecb(%s)",
514 cipher_name) >= CRYPTO_MAX_ALG_NAME)
515 goto err_free_inst;
516
517 err = crypto_grab_lskcipher(spawn,
518 lskcipher_crypto_instance(inst),
519 ecb_name, 0, mask);
520 }
521
522 if (err)
523 goto err_free_inst;
524
525 cipher_alg = crypto_lskcipher_spawn_alg(spawn);
526
527 err = crypto_inst_setname(lskcipher_crypto_instance(inst), tmpl->name,
528 &cipher_alg->co.base);
529 if (err)
530 goto err_free_inst;
531
532 if (ecb_name[0]) {
533 int len;
534
535 err = -EINVAL;
536 len = strscpy(ecb_name, &cipher_alg->co.base.cra_name[4],
537 sizeof(ecb_name));
538 if (len < 2)
539 goto err_free_inst;
540
541 if (ecb_name[len - 1] != ')')
542 goto err_free_inst;
543
544 ecb_name[len - 1] = 0;
545
546 err = -ENAMETOOLONG;
547 if (snprintf(inst->alg.co.base.cra_name, CRYPTO_MAX_ALG_NAME,
548 "%s(%s)", tmpl->name, ecb_name) >=
549 CRYPTO_MAX_ALG_NAME)
550 goto err_free_inst;
551
552 if (strcmp(ecb_name, cipher_name) &&
553 snprintf(inst->alg.co.base.cra_driver_name,
554 CRYPTO_MAX_ALG_NAME,
555 "%s(%s)", tmpl->name, cipher_name) >=
556 CRYPTO_MAX_ALG_NAME)
557 goto err_free_inst;
558 } else {
559 /* Don't allow nesting. */
560 err = -ELOOP;
561 if ((cipher_alg->co.base.cra_flags & CRYPTO_ALG_INSTANCE))
562 goto err_free_inst;
563 }
564
565 err = -EINVAL;
566 if (cipher_alg->co.ivsize)
567 goto err_free_inst;
568
569 inst->free = lskcipher_free_instance_simple;
570
571 /* Default algorithm properties, can be overridden */
572 inst->alg.co.base.cra_blocksize = cipher_alg->co.base.cra_blocksize;
573 inst->alg.co.base.cra_alignmask = cipher_alg->co.base.cra_alignmask;
574 inst->alg.co.base.cra_priority = cipher_alg->co.base.cra_priority;
575 inst->alg.co.min_keysize = cipher_alg->co.min_keysize;
576 inst->alg.co.max_keysize = cipher_alg->co.max_keysize;
577 inst->alg.co.ivsize = cipher_alg->co.base.cra_blocksize;
578 inst->alg.co.statesize = cipher_alg->co.statesize;
579
580 /* Use struct crypto_lskcipher * by default, can be overridden */
581 inst->alg.co.base.cra_ctxsize = sizeof(struct crypto_lskcipher *);
582 inst->alg.setkey = lskcipher_setkey_simple;
583 inst->alg.init = lskcipher_init_tfm_simple;
584 inst->alg.exit = lskcipher_exit_tfm_simple;
585
586 return inst;
587
588 err_free_inst:
589 lskcipher_free_instance_simple(inst);
590 return ERR_PTR(err);
591 }
592 EXPORT_SYMBOL_GPL(lskcipher_alloc_instance_simple);
593
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