lskcipher.c

  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	.algsize = offsetof(struct lskcipher_alg, co.base),
298};
299
300static void crypto_lskcipher_exit_tfm_sg(struct crypto_tfm *tfm)
301{
302	struct crypto_lskcipher **ctx = crypto_tfm_ctx(tfm);
303
304	crypto_free_lskcipher(*ctx);
305}
306
307int crypto_init_lskcipher_ops_sg(struct crypto_tfm *tfm)
308{
309	struct crypto_lskcipher **ctx = crypto_tfm_ctx(tfm);
310	struct crypto_alg *calg = tfm->__crt_alg;
311	struct crypto_lskcipher *skcipher;
312
313	if (!crypto_mod_get(calg))
314		return -EAGAIN;
315
316	skcipher = crypto_create_tfm(calg, &crypto_lskcipher_type);
317	if (IS_ERR(skcipher)) {
318		crypto_mod_put(calg);
319		return PTR_ERR(skcipher);
320	}
321
322	*ctx = skcipher;
323	tfm->exit = crypto_lskcipher_exit_tfm_sg;
324
325	return 0;
326}
327
328int crypto_grab_lskcipher(struct crypto_lskcipher_spawn *spawn,
329			  struct crypto_instance *inst,
330			  const char *name, u32 type, u32 mask)
331{
332	spawn->base.frontend = &crypto_lskcipher_type;
333	return crypto_grab_spawn(&spawn->base, inst, name, type, mask);
334}
335EXPORT_SYMBOL_GPL(crypto_grab_lskcipher);
336
337struct crypto_lskcipher *crypto_alloc_lskcipher(const char *alg_name,
338						u32 type, u32 mask)
339{
340	return crypto_alloc_tfm(alg_name, &crypto_lskcipher_type, type, mask);
341}
342EXPORT_SYMBOL_GPL(crypto_alloc_lskcipher);
343
344static int lskcipher_prepare_alg(struct lskcipher_alg *alg)
345{
346	struct crypto_alg *base = &alg->co.base;
347	int err;
348
349	err = skcipher_prepare_alg_common(&alg->co);
350	if (err)
351		return err;
352
353	if (alg->co.chunksize & (alg->co.chunksize - 1))
354		return -EINVAL;
355
356	base->cra_type = &crypto_lskcipher_type;
357	base->cra_flags |= CRYPTO_ALG_TYPE_LSKCIPHER;
358
359	return 0;
360}
361
362int crypto_register_lskcipher(struct lskcipher_alg *alg)
363{
364	struct crypto_alg *base = &alg->co.base;
365	int err;
366
367	err = lskcipher_prepare_alg(alg);
368	if (err)
369		return err;
370
371	return crypto_register_alg(base);
372}
373EXPORT_SYMBOL_GPL(crypto_register_lskcipher);
374
375void crypto_unregister_lskcipher(struct lskcipher_alg *alg)
376{
377	crypto_unregister_alg(&alg->co.base);
378}
379EXPORT_SYMBOL_GPL(crypto_unregister_lskcipher);
380
381int crypto_register_lskciphers(struct lskcipher_alg *algs, int count)
382{
383	int i, ret;
384
385	for (i = 0; i < count; i++) {
386		ret = crypto_register_lskcipher(&algs[i]);
387		if (ret)
388			goto err;
389	}
390
391	return 0;
392
393err:
394	for (--i; i >= 0; --i)
395		crypto_unregister_lskcipher(&algs[i]);
396
397	return ret;
398}
399EXPORT_SYMBOL_GPL(crypto_register_lskciphers);
400
401void crypto_unregister_lskciphers(struct lskcipher_alg *algs, int count)
402{
403	int i;
404
405	for (i = count - 1; i >= 0; --i)
406		crypto_unregister_lskcipher(&algs[i]);
407}
408EXPORT_SYMBOL_GPL(crypto_unregister_lskciphers);
409
410int lskcipher_register_instance(struct crypto_template *tmpl,
411				struct lskcipher_instance *inst)
412{
413	int err;
414
415	if (WARN_ON(!inst->free))
416		return -EINVAL;
417
418	err = lskcipher_prepare_alg(&inst->alg);
419	if (err)
420		return err;
421
422	return crypto_register_instance(tmpl, lskcipher_crypto_instance(inst));
423}
424EXPORT_SYMBOL_GPL(lskcipher_register_instance);
425
426static int lskcipher_setkey_simple(struct crypto_lskcipher *tfm, const u8 *key,
427				   unsigned int keylen)
428{
429	struct crypto_lskcipher *cipher = lskcipher_cipher_simple(tfm);
430
431	crypto_lskcipher_clear_flags(cipher, CRYPTO_TFM_REQ_MASK);
432	crypto_lskcipher_set_flags(cipher, crypto_lskcipher_get_flags(tfm) &
433				   CRYPTO_TFM_REQ_MASK);
434	return crypto_lskcipher_setkey(cipher, key, keylen);
435}
436
437static int lskcipher_init_tfm_simple(struct crypto_lskcipher *tfm)
438{
439	struct lskcipher_instance *inst = lskcipher_alg_instance(tfm);
440	struct crypto_lskcipher **ctx = crypto_lskcipher_ctx(tfm);
441	struct crypto_lskcipher_spawn *spawn;
442	struct crypto_lskcipher *cipher;
443
444	spawn = lskcipher_instance_ctx(inst);
445	cipher = crypto_spawn_lskcipher(spawn);
446	if (IS_ERR(cipher))
447		return PTR_ERR(cipher);
448
449	*ctx = cipher;
450	return 0;
451}
452
453static void lskcipher_exit_tfm_simple(struct crypto_lskcipher *tfm)
454{
455	struct crypto_lskcipher **ctx = crypto_lskcipher_ctx(tfm);
456
457	crypto_free_lskcipher(*ctx);
458}
459
460static void lskcipher_free_instance_simple(struct lskcipher_instance *inst)
461{
462	crypto_drop_lskcipher(lskcipher_instance_ctx(inst));
463	kfree(inst);
464}
465
466/**
467 * lskcipher_alloc_instance_simple - allocate instance of simple block cipher
468 *
469 * Allocate an lskcipher_instance for a simple block cipher mode of operation,
470 * e.g. cbc or ecb.  The instance context will have just a single crypto_spawn,
471 * that for the underlying cipher.  The {min,max}_keysize, ivsize, blocksize,
472 * alignmask, and priority are set from the underlying cipher but can be
473 * overridden if needed.  The tfm context defaults to
474 * struct crypto_lskcipher *, and default ->setkey(), ->init(), and
475 * ->exit() methods are installed.
476 *
477 * @tmpl: the template being instantiated
478 * @tb: the template parameters
479 *
480 * Return: a pointer to the new instance, or an ERR_PTR().  The caller still
481 *	   needs to register the instance.
482 */
483struct lskcipher_instance *lskcipher_alloc_instance_simple(
484	struct crypto_template *tmpl, struct rtattr **tb)
485{
486	u32 mask;
487	struct lskcipher_instance *inst;
488	struct crypto_lskcipher_spawn *spawn;
489	char ecb_name[CRYPTO_MAX_ALG_NAME];
490	struct lskcipher_alg *cipher_alg;
491	const char *cipher_name;
492	int err;
493
494	err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_LSKCIPHER, &mask);
495	if (err)
496		return ERR_PTR(err);
497
498	cipher_name = crypto_attr_alg_name(tb[1]);
499	if (IS_ERR(cipher_name))
500		return ERR_CAST(cipher_name);
501
502	inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
503	if (!inst)
504		return ERR_PTR(-ENOMEM);
505
506	spawn = lskcipher_instance_ctx(inst);
507	err = crypto_grab_lskcipher(spawn,
508				    lskcipher_crypto_instance(inst),
509				    cipher_name, 0, mask);
510
511	ecb_name[0] = 0;
512	if (err == -ENOENT && !!memcmp(tmpl->name, "ecb", 4)) {
513		err = -ENAMETOOLONG;
514		if (snprintf(ecb_name, CRYPTO_MAX_ALG_NAME, "ecb(%s)",
515			     cipher_name) >= CRYPTO_MAX_ALG_NAME)
516			goto err_free_inst;
517
518		err = crypto_grab_lskcipher(spawn,
519					    lskcipher_crypto_instance(inst),
520					    ecb_name, 0, mask);
521	}
522
523	if (err)
524		goto err_free_inst;
525
526	cipher_alg = crypto_lskcipher_spawn_alg(spawn);
527
528	err = crypto_inst_setname(lskcipher_crypto_instance(inst), tmpl->name,
529				  &cipher_alg->co.base);
530	if (err)
531		goto err_free_inst;
532
533	if (ecb_name[0]) {
534		int len;
535
536		err = -EINVAL;
537		len = strscpy(ecb_name, &cipher_alg->co.base.cra_name[4],
538			      sizeof(ecb_name));
539		if (len < 2)
540			goto err_free_inst;
541
542		if (ecb_name[len - 1] != ')')
543			goto err_free_inst;
544
545		ecb_name[len - 1] = 0;
546
547		err = -ENAMETOOLONG;
548		if (snprintf(inst->alg.co.base.cra_name, CRYPTO_MAX_ALG_NAME,
549			     "%s(%s)", tmpl->name, ecb_name) >=
550		    CRYPTO_MAX_ALG_NAME)
551			goto err_free_inst;
552
553		if (strcmp(ecb_name, cipher_name) &&
554		    snprintf(inst->alg.co.base.cra_driver_name,
555			     CRYPTO_MAX_ALG_NAME,
556			     "%s(%s)", tmpl->name, cipher_name) >=
557		    CRYPTO_MAX_ALG_NAME)
558			goto err_free_inst;
559	} else {
560		/* Don't allow nesting. */
561		err = -ELOOP;
562		if ((cipher_alg->co.base.cra_flags & CRYPTO_ALG_INSTANCE))
563			goto err_free_inst;
564	}
565
566	err = -EINVAL;
567	if (cipher_alg->co.ivsize)
568		goto err_free_inst;
569
570	inst->free = lskcipher_free_instance_simple;
571
572	/* Default algorithm properties, can be overridden */
573	inst->alg.co.base.cra_blocksize = cipher_alg->co.base.cra_blocksize;
574	inst->alg.co.base.cra_alignmask = cipher_alg->co.base.cra_alignmask;
575	inst->alg.co.base.cra_priority = cipher_alg->co.base.cra_priority;
576	inst->alg.co.min_keysize = cipher_alg->co.min_keysize;
577	inst->alg.co.max_keysize = cipher_alg->co.max_keysize;
578	inst->alg.co.ivsize = cipher_alg->co.base.cra_blocksize;
579	inst->alg.co.statesize = cipher_alg->co.statesize;
580
581	/* Use struct crypto_lskcipher * by default, can be overridden */
582	inst->alg.co.base.cra_ctxsize = sizeof(struct crypto_lskcipher *);
583	inst->alg.setkey = lskcipher_setkey_simple;
584	inst->alg.init = lskcipher_init_tfm_simple;
585	inst->alg.exit = lskcipher_exit_tfm_simple;
586
587	return inst;
588
589err_free_inst:
590	lskcipher_free_instance_simple(inst);
591	return ERR_PTR(err);
592}
593EXPORT_SYMBOL_GPL(lskcipher_alloc_instance_simple);