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
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		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
116out:
117	memcpy(iv, tiv, ivsize + statesize);
118	kfree_sensitive(p);
119	kfree_sensitive(tiv);
120	return err;
121}
122
123static 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
140int 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}
147EXPORT_SYMBOL_GPL(crypto_lskcipher_encrypt);
148
149int 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}
156EXPORT_SYMBOL_GPL(crypto_lskcipher_decrypt);
157
158static 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
201int 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
210int 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
219static 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
227static 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
241static 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
249static 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
263static 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
283static 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
299static 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
306int 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
327int 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}
334EXPORT_SYMBOL_GPL(crypto_grab_lskcipher);
335
336struct 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}
341EXPORT_SYMBOL_GPL(crypto_alloc_lskcipher);
342
343static 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
361int 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}
372EXPORT_SYMBOL_GPL(crypto_register_lskcipher);
373
374void crypto_unregister_lskcipher(struct lskcipher_alg *alg)
375{
376	crypto_unregister_alg(&alg->co.base);
377}
378EXPORT_SYMBOL_GPL(crypto_unregister_lskcipher);
379
380int 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
392err:
393	for (--i; i >= 0; --i)
394		crypto_unregister_lskcipher(&algs[i]);
395
396	return ret;
397}
398EXPORT_SYMBOL_GPL(crypto_register_lskciphers);
399
400void 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}
407EXPORT_SYMBOL_GPL(crypto_unregister_lskciphers);
408
409int 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}
423EXPORT_SYMBOL_GPL(lskcipher_register_instance);
424
425static 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
436static 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
452static 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
459static 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 */
482struct 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
588err_free_inst:
589	lskcipher_free_instance_simple(inst);
590	return ERR_PTR(err);
591}
592EXPORT_SYMBOL_GPL(lskcipher_alloc_instance_simple);
593