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