1/*
2 * Synchronous Cryptographic Hash operations.
3 *
4 * Copyright (c) 2008 Herbert Xu <herbert@gondor.apana.org.au>
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License as published by the Free
8 * Software Foundation; either version 2 of the License, or (at your option)
9 * any later version.
10 *
11 */
12
13#include <crypto/scatterwalk.h>
14#include <crypto/internal/hash.h>
15#include <linux/err.h>
16#include <linux/kernel.h>
17#include <linux/module.h>
18#include <linux/slab.h>
19#include <linux/seq_file.h>
20#include <linux/cryptouser.h>
21#include <net/netlink.h>
22
23#include "internal.h"
24
25static const struct crypto_type crypto_shash_type;
26
27static int shash_no_setkey(struct crypto_shash *tfm, const u8 *key,
28			   unsigned int keylen)
29{
30	return -ENOSYS;
31}
32
33static int shash_setkey_unaligned(struct crypto_shash *tfm, const u8 *key,
34				  unsigned int keylen)
35{
36	struct shash_alg *shash = crypto_shash_alg(tfm);
37	unsigned long alignmask = crypto_shash_alignmask(tfm);
38	unsigned long absize;
39	u8 *buffer, *alignbuffer;
40	int err;
41
42	absize = keylen + (alignmask & ~(crypto_tfm_ctx_alignment() - 1));
43	buffer = kmalloc(absize, GFP_KERNEL);
44	if (!buffer)
45		return -ENOMEM;
46
47	alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
48	memcpy(alignbuffer, key, keylen);
49	err = shash->setkey(tfm, alignbuffer, keylen);
50	kzfree(buffer);
51	return err;
52}
53
54int crypto_shash_setkey(struct crypto_shash *tfm, const u8 *key,
55			unsigned int keylen)
56{
57	struct shash_alg *shash = crypto_shash_alg(tfm);
58	unsigned long alignmask = crypto_shash_alignmask(tfm);
59
60	if ((unsigned long)key & alignmask)
61		return shash_setkey_unaligned(tfm, key, keylen);
62
63	return shash->setkey(tfm, key, keylen);
64}
65EXPORT_SYMBOL_GPL(crypto_shash_setkey);
66
67static inline unsigned int shash_align_buffer_size(unsigned len,
68						   unsigned long mask)
69{
70	typedef u8 __attribute__ ((aligned)) u8_aligned;
71	return len + (mask & ~(__alignof__(u8_aligned) - 1));
72}
73
74static int shash_update_unaligned(struct shash_desc *desc, const u8 *data,
75				  unsigned int len)
76{
77	struct crypto_shash *tfm = desc->tfm;
78	struct shash_alg *shash = crypto_shash_alg(tfm);
79	unsigned long alignmask = crypto_shash_alignmask(tfm);
80	unsigned int unaligned_len = alignmask + 1 -
81				     ((unsigned long)data & alignmask);
82	u8 ubuf[shash_align_buffer_size(unaligned_len, alignmask)]
83		__attribute__ ((aligned));
84	u8 *buf = PTR_ALIGN(&ubuf[0], alignmask + 1);
85	int err;
86
87	if (unaligned_len > len)
88		unaligned_len = len;
89
90	memcpy(buf, data, unaligned_len);
91	err = shash->update(desc, buf, unaligned_len);
92	memset(buf, 0, unaligned_len);
93
94	return err ?:
95	       shash->update(desc, data + unaligned_len, len - unaligned_len);
96}
97
98int crypto_shash_update(struct shash_desc *desc, const u8 *data,
99			unsigned int len)
100{
101	struct crypto_shash *tfm = desc->tfm;
102	struct shash_alg *shash = crypto_shash_alg(tfm);
103	unsigned long alignmask = crypto_shash_alignmask(tfm);
104
105	if ((unsigned long)data & alignmask)
106		return shash_update_unaligned(desc, data, len);
107
108	return shash->update(desc, data, len);
109}
110EXPORT_SYMBOL_GPL(crypto_shash_update);
111
112static int shash_final_unaligned(struct shash_desc *desc, u8 *out)
113{
114	struct crypto_shash *tfm = desc->tfm;
115	unsigned long alignmask = crypto_shash_alignmask(tfm);
116	struct shash_alg *shash = crypto_shash_alg(tfm);
117	unsigned int ds = crypto_shash_digestsize(tfm);
118	u8 ubuf[shash_align_buffer_size(ds, alignmask)]
119		__attribute__ ((aligned));
120	u8 *buf = PTR_ALIGN(&ubuf[0], alignmask + 1);
121	int err;
122
123	err = shash->final(desc, buf);
124	if (err)
125		goto out;
126
127	memcpy(out, buf, ds);
128
129out:
130	memset(buf, 0, ds);
131	return err;
132}
133
134int crypto_shash_final(struct shash_desc *desc, u8 *out)
135{
136	struct crypto_shash *tfm = desc->tfm;
137	struct shash_alg *shash = crypto_shash_alg(tfm);
138	unsigned long alignmask = crypto_shash_alignmask(tfm);
139
140	if ((unsigned long)out & alignmask)
141		return shash_final_unaligned(desc, out);
142
143	return shash->final(desc, out);
144}
145EXPORT_SYMBOL_GPL(crypto_shash_final);
146
147static int shash_finup_unaligned(struct shash_desc *desc, const u8 *data,
148				 unsigned int len, u8 *out)
149{
150	return crypto_shash_update(desc, data, len) ?:
151	       crypto_shash_final(desc, out);
152}
153
154int crypto_shash_finup(struct shash_desc *desc, const u8 *data,
155		       unsigned int len, u8 *out)
156{
157	struct crypto_shash *tfm = desc->tfm;
158	struct shash_alg *shash = crypto_shash_alg(tfm);
159	unsigned long alignmask = crypto_shash_alignmask(tfm);
160
161	if (((unsigned long)data | (unsigned long)out) & alignmask)
162		return shash_finup_unaligned(desc, data, len, out);
163
164	return shash->finup(desc, data, len, out);
165}
166EXPORT_SYMBOL_GPL(crypto_shash_finup);
167
168static int shash_digest_unaligned(struct shash_desc *desc, const u8 *data,
169				  unsigned int len, u8 *out)
170{
171	return crypto_shash_init(desc) ?:
172	       crypto_shash_finup(desc, data, len, out);
173}
174
175int crypto_shash_digest(struct shash_desc *desc, const u8 *data,
176			unsigned int len, u8 *out)
177{
178	struct crypto_shash *tfm = desc->tfm;
179	struct shash_alg *shash = crypto_shash_alg(tfm);
180	unsigned long alignmask = crypto_shash_alignmask(tfm);
181
182	if (((unsigned long)data | (unsigned long)out) & alignmask)
183		return shash_digest_unaligned(desc, data, len, out);
184
185	return shash->digest(desc, data, len, out);
186}
187EXPORT_SYMBOL_GPL(crypto_shash_digest);
188
189static int shash_default_export(struct shash_desc *desc, void *out)
190{
191	memcpy(out, shash_desc_ctx(desc), crypto_shash_descsize(desc->tfm));
192	return 0;
193}
194
195static int shash_default_import(struct shash_desc *desc, const void *in)
196{
197	memcpy(shash_desc_ctx(desc), in, crypto_shash_descsize(desc->tfm));
198	return 0;
199}
200
201static int shash_async_setkey(struct crypto_ahash *tfm, const u8 *key,
202			      unsigned int keylen)
203{
204	struct crypto_shash **ctx = crypto_ahash_ctx(tfm);
205
206	return crypto_shash_setkey(*ctx, key, keylen);
207}
208
209static int shash_async_init(struct ahash_request *req)
210{
211	struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
212	struct shash_desc *desc = ahash_request_ctx(req);
213
214	desc->tfm = *ctx;
215	desc->flags = req->base.flags;
216
217	return crypto_shash_init(desc);
218}
219
220int shash_ahash_update(struct ahash_request *req, struct shash_desc *desc)
221{
222	struct crypto_hash_walk walk;
223	int nbytes;
224
225	for (nbytes = crypto_hash_walk_first(req, &walk); nbytes > 0;
226	     nbytes = crypto_hash_walk_done(&walk, nbytes))
227		nbytes = crypto_shash_update(desc, walk.data, nbytes);
228
229	return nbytes;
230}
231EXPORT_SYMBOL_GPL(shash_ahash_update);
232
233static int shash_async_update(struct ahash_request *req)
234{
235	return shash_ahash_update(req, ahash_request_ctx(req));
236}
237
238static int shash_async_final(struct ahash_request *req)
239{
240	return crypto_shash_final(ahash_request_ctx(req), req->result);
241}
242
243int shash_ahash_finup(struct ahash_request *req, struct shash_desc *desc)
244{
245	struct crypto_hash_walk walk;
246	int nbytes;
247
248	nbytes = crypto_hash_walk_first(req, &walk);
249	if (!nbytes)
250		return crypto_shash_final(desc, req->result);
251
252	do {
253		nbytes = crypto_hash_walk_last(&walk) ?
254			 crypto_shash_finup(desc, walk.data, nbytes,
255					    req->result) :
256			 crypto_shash_update(desc, walk.data, nbytes);
257		nbytes = crypto_hash_walk_done(&walk, nbytes);
258	} while (nbytes > 0);
259
260	return nbytes;
261}
262EXPORT_SYMBOL_GPL(shash_ahash_finup);
263
264static int shash_async_finup(struct ahash_request *req)
265{
266	struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
267	struct shash_desc *desc = ahash_request_ctx(req);
268
269	desc->tfm = *ctx;
270	desc->flags = req->base.flags;
271
272	return shash_ahash_finup(req, desc);
273}
274
275int shash_ahash_digest(struct ahash_request *req, struct shash_desc *desc)
276{
277	struct scatterlist *sg = req->src;
278	unsigned int offset = sg->offset;
279	unsigned int nbytes = req->nbytes;
280	int err;
281
282	if (nbytes < min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset)) {
283		void *data;
284
285		data = kmap_atomic(sg_page(sg));
286		err = crypto_shash_digest(desc, data + offset, nbytes,
287					  req->result);
288		kunmap_atomic(data);
289		crypto_yield(desc->flags);
290	} else
291		err = crypto_shash_init(desc) ?:
292		      shash_ahash_finup(req, desc);
293
294	return err;
295}
296EXPORT_SYMBOL_GPL(shash_ahash_digest);
297
298static int shash_async_digest(struct ahash_request *req)
299{
300	struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
301	struct shash_desc *desc = ahash_request_ctx(req);
302
303	desc->tfm = *ctx;
304	desc->flags = req->base.flags;
305
306	return shash_ahash_digest(req, desc);
307}
308
309static int shash_async_export(struct ahash_request *req, void *out)
310{
311	return crypto_shash_export(ahash_request_ctx(req), out);
312}
313
314static int shash_async_import(struct ahash_request *req, const void *in)
315{
316	struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
317	struct shash_desc *desc = ahash_request_ctx(req);
318
319	desc->tfm = *ctx;
320	desc->flags = req->base.flags;
321
322	return crypto_shash_import(desc, in);
323}
324
325static void crypto_exit_shash_ops_async(struct crypto_tfm *tfm)
326{
327	struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
328
329	crypto_free_shash(*ctx);
330}
331
332int crypto_init_shash_ops_async(struct crypto_tfm *tfm)
333{
334	struct crypto_alg *calg = tfm->__crt_alg;
335	struct shash_alg *alg = __crypto_shash_alg(calg);
336	struct crypto_ahash *crt = __crypto_ahash_cast(tfm);
337	struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
338	struct crypto_shash *shash;
339
340	if (!crypto_mod_get(calg))
341		return -EAGAIN;
342
343	shash = crypto_create_tfm(calg, &crypto_shash_type);
344	if (IS_ERR(shash)) {
345		crypto_mod_put(calg);
346		return PTR_ERR(shash);
347	}
348
349	*ctx = shash;
350	tfm->exit = crypto_exit_shash_ops_async;
351
352	crt->init = shash_async_init;
353	crt->update = shash_async_update;
354	crt->final = shash_async_final;
355	crt->finup = shash_async_finup;
356	crt->digest = shash_async_digest;
357	crt->setkey = shash_async_setkey;
358
359	crt->has_setkey = alg->setkey != shash_no_setkey;
360
361	if (alg->export)
362		crt->export = shash_async_export;
363	if (alg->import)
364		crt->import = shash_async_import;
365
366	crt->reqsize = sizeof(struct shash_desc) + crypto_shash_descsize(shash);
367
368	return 0;
369}
370
371static int shash_compat_setkey(struct crypto_hash *tfm, const u8 *key,
372			       unsigned int keylen)
373{
374	struct shash_desc **descp = crypto_hash_ctx(tfm);
375	struct shash_desc *desc = *descp;
376
377	return crypto_shash_setkey(desc->tfm, key, keylen);
378}
379
380static int shash_compat_init(struct hash_desc *hdesc)
381{
382	struct shash_desc **descp = crypto_hash_ctx(hdesc->tfm);
383	struct shash_desc *desc = *descp;
384
385	desc->flags = hdesc->flags;
386
387	return crypto_shash_init(desc);
388}
389
390static int shash_compat_update(struct hash_desc *hdesc, struct scatterlist *sg,
391			       unsigned int len)
392{
393	struct shash_desc **descp = crypto_hash_ctx(hdesc->tfm);
394	struct shash_desc *desc = *descp;
395	struct crypto_hash_walk walk;
396	int nbytes;
397
398	for (nbytes = crypto_hash_walk_first_compat(hdesc, &walk, sg, len);
399	     nbytes > 0; nbytes = crypto_hash_walk_done(&walk, nbytes))
400		nbytes = crypto_shash_update(desc, walk.data, nbytes);
401
402	return nbytes;
403}
404
405static int shash_compat_final(struct hash_desc *hdesc, u8 *out)
406{
407	struct shash_desc **descp = crypto_hash_ctx(hdesc->tfm);
408
409	return crypto_shash_final(*descp, out);
410}
411
412static int shash_compat_digest(struct hash_desc *hdesc, struct scatterlist *sg,
413			       unsigned int nbytes, u8 *out)
414{
415	unsigned int offset = sg->offset;
416	int err;
417
418	if (nbytes < min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset)) {
419		struct shash_desc **descp = crypto_hash_ctx(hdesc->tfm);
420		struct shash_desc *desc = *descp;
421		void *data;
422
423		desc->flags = hdesc->flags;
424
425		data = kmap_atomic(sg_page(sg));
426		err = crypto_shash_digest(desc, data + offset, nbytes, out);
427		kunmap_atomic(data);
428		crypto_yield(desc->flags);
429		goto out;
430	}
431
432	err = shash_compat_init(hdesc);
433	if (err)
434		goto out;
435
436	err = shash_compat_update(hdesc, sg, nbytes);
437	if (err)
438		goto out;
439
440	err = shash_compat_final(hdesc, out);
441
442out:
443	return err;
444}
445
446static void crypto_exit_shash_ops_compat(struct crypto_tfm *tfm)
447{
448	struct shash_desc **descp = crypto_tfm_ctx(tfm);
449	struct shash_desc *desc = *descp;
450
451	crypto_free_shash(desc->tfm);
452	kzfree(desc);
453}
454
455static int crypto_init_shash_ops_compat(struct crypto_tfm *tfm)
456{
457	struct hash_tfm *crt = &tfm->crt_hash;
458	struct crypto_alg *calg = tfm->__crt_alg;
459	struct shash_alg *alg = __crypto_shash_alg(calg);
460	struct shash_desc **descp = crypto_tfm_ctx(tfm);
461	struct crypto_shash *shash;
462	struct shash_desc *desc;
463
464	if (!crypto_mod_get(calg))
465		return -EAGAIN;
466
467	shash = crypto_create_tfm(calg, &crypto_shash_type);
468	if (IS_ERR(shash)) {
469		crypto_mod_put(calg);
470		return PTR_ERR(shash);
471	}
472
473	desc = kmalloc(sizeof(*desc) + crypto_shash_descsize(shash),
474		       GFP_KERNEL);
475	if (!desc) {
476		crypto_free_shash(shash);
477		return -ENOMEM;
478	}
479
480	*descp = desc;
481	desc->tfm = shash;
482	tfm->exit = crypto_exit_shash_ops_compat;
483
484	crt->init = shash_compat_init;
485	crt->update = shash_compat_update;
486	crt->final  = shash_compat_final;
487	crt->digest = shash_compat_digest;
488	crt->setkey = shash_compat_setkey;
489
490	crt->digestsize = alg->digestsize;
491
492	return 0;
493}
494
495static int crypto_init_shash_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
496{
497	switch (mask & CRYPTO_ALG_TYPE_MASK) {
498	case CRYPTO_ALG_TYPE_HASH_MASK:
499		return crypto_init_shash_ops_compat(tfm);
500	}
501
502	return -EINVAL;
503}
504
505static unsigned int crypto_shash_ctxsize(struct crypto_alg *alg, u32 type,
506					 u32 mask)
507{
508	switch (mask & CRYPTO_ALG_TYPE_MASK) {
509	case CRYPTO_ALG_TYPE_HASH_MASK:
510		return sizeof(struct shash_desc *);
511	}
512
513	return 0;
514}
515
516static int crypto_shash_init_tfm(struct crypto_tfm *tfm)
517{
518	struct crypto_shash *hash = __crypto_shash_cast(tfm);
519
520	hash->descsize = crypto_shash_alg(hash)->descsize;
521	return 0;
522}
523
524static unsigned int crypto_shash_extsize(struct crypto_alg *alg)
525{
526	return alg->cra_ctxsize;
527}
528
529#ifdef CONFIG_NET
530static int crypto_shash_report(struct sk_buff *skb, struct crypto_alg *alg)
531{
532	struct crypto_report_hash rhash;
533	struct shash_alg *salg = __crypto_shash_alg(alg);
534
535	strncpy(rhash.type, "shash", sizeof(rhash.type));
536
537	rhash.blocksize = alg->cra_blocksize;
538	rhash.digestsize = salg->digestsize;
539
540	if (nla_put(skb, CRYPTOCFGA_REPORT_HASH,
541		    sizeof(struct crypto_report_hash), &rhash))
542		goto nla_put_failure;
543	return 0;
544
545nla_put_failure:
546	return -EMSGSIZE;
547}
548#else
549static int crypto_shash_report(struct sk_buff *skb, struct crypto_alg *alg)
550{
551	return -ENOSYS;
552}
553#endif
554
555static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
556	__attribute__ ((unused));
557static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
558{
559	struct shash_alg *salg = __crypto_shash_alg(alg);
560
561	seq_printf(m, "type         : shash\n");
562	seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
563	seq_printf(m, "digestsize   : %u\n", salg->digestsize);
564}
565
566static const struct crypto_type crypto_shash_type = {
567	.ctxsize = crypto_shash_ctxsize,
568	.extsize = crypto_shash_extsize,
569	.init = crypto_init_shash_ops,
570	.init_tfm = crypto_shash_init_tfm,
571#ifdef CONFIG_PROC_FS
572	.show = crypto_shash_show,
573#endif
574	.report = crypto_shash_report,
575	.maskclear = ~CRYPTO_ALG_TYPE_MASK,
576	.maskset = CRYPTO_ALG_TYPE_MASK,
577	.type = CRYPTO_ALG_TYPE_SHASH,
578	.tfmsize = offsetof(struct crypto_shash, base),
579};
580
581struct crypto_shash *crypto_alloc_shash(const char *alg_name, u32 type,
582					u32 mask)
583{
584	return crypto_alloc_tfm(alg_name, &crypto_shash_type, type, mask);
585}
586EXPORT_SYMBOL_GPL(crypto_alloc_shash);
587
588static int shash_prepare_alg(struct shash_alg *alg)
589{
590	struct crypto_alg *base = &alg->base;
591
592	if (alg->digestsize > PAGE_SIZE / 8 ||
593	    alg->descsize > PAGE_SIZE / 8 ||
594	    alg->statesize > PAGE_SIZE / 8)
595		return -EINVAL;
596
597	base->cra_type = &crypto_shash_type;
598	base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
599	base->cra_flags |= CRYPTO_ALG_TYPE_SHASH;
600
601	if (!alg->finup)
602		alg->finup = shash_finup_unaligned;
603	if (!alg->digest)
604		alg->digest = shash_digest_unaligned;
605	if (!alg->export) {
606		alg->export = shash_default_export;
607		alg->import = shash_default_import;
608		alg->statesize = alg->descsize;
609	}
610	if (!alg->setkey)
611		alg->setkey = shash_no_setkey;
612
613	return 0;
614}
615
616int crypto_register_shash(struct shash_alg *alg)
617{
618	struct crypto_alg *base = &alg->base;
619	int err;
620
621	err = shash_prepare_alg(alg);
622	if (err)
623		return err;
624
625	return crypto_register_alg(base);
626}
627EXPORT_SYMBOL_GPL(crypto_register_shash);
628
629int crypto_unregister_shash(struct shash_alg *alg)
630{
631	return crypto_unregister_alg(&alg->base);
632}
633EXPORT_SYMBOL_GPL(crypto_unregister_shash);
634
635int crypto_register_shashes(struct shash_alg *algs, int count)
636{
637	int i, ret;
638
639	for (i = 0; i < count; i++) {
640		ret = crypto_register_shash(&algs[i]);
641		if (ret)
642			goto err;
643	}
644
645	return 0;
646
647err:
648	for (--i; i >= 0; --i)
649		crypto_unregister_shash(&algs[i]);
650
651	return ret;
652}
653EXPORT_SYMBOL_GPL(crypto_register_shashes);
654
655int crypto_unregister_shashes(struct shash_alg *algs, int count)
656{
657	int i, ret;
658
659	for (i = count - 1; i >= 0; --i) {
660		ret = crypto_unregister_shash(&algs[i]);
661		if (ret)
662			pr_err("Failed to unregister %s %s: %d\n",
663			       algs[i].base.cra_driver_name,
664			       algs[i].base.cra_name, ret);
665	}
666
667	return 0;
668}
669EXPORT_SYMBOL_GPL(crypto_unregister_shashes);
670
671int shash_register_instance(struct crypto_template *tmpl,
672			    struct shash_instance *inst)
673{
674	int err;
675
676	err = shash_prepare_alg(&inst->alg);
677	if (err)
678		return err;
679
680	return crypto_register_instance(tmpl, shash_crypto_instance(inst));
681}
682EXPORT_SYMBOL_GPL(shash_register_instance);
683
684void shash_free_instance(struct crypto_instance *inst)
685{
686	crypto_drop_spawn(crypto_instance_ctx(inst));
687	kfree(shash_instance(inst));
688}
689EXPORT_SYMBOL_GPL(shash_free_instance);
690
691int crypto_init_shash_spawn(struct crypto_shash_spawn *spawn,
692			    struct shash_alg *alg,
693			    struct crypto_instance *inst)
694{
695	return crypto_init_spawn2(&spawn->base, &alg->base, inst,
696				  &crypto_shash_type);
697}
698EXPORT_SYMBOL_GPL(crypto_init_shash_spawn);
699
700struct shash_alg *shash_attr_alg(struct rtattr *rta, u32 type, u32 mask)
701{
702	struct crypto_alg *alg;
703
704	alg = crypto_attr_alg2(rta, &crypto_shash_type, type, mask);
705	return IS_ERR(alg) ? ERR_CAST(alg) :
706	       container_of(alg, struct shash_alg, base);
707}
708EXPORT_SYMBOL_GPL(shash_attr_alg);
709
710MODULE_LICENSE("GPL");
711MODULE_DESCRIPTION("Synchronous cryptographic hash type");
712