1/*
2 * Asynchronous Cryptographic Hash operations.
3 *
4 * This is the asynchronous version of hash.c with notification of
5 * completion via a callback.
6 *
7 * Copyright (c) 2008 Loc Ho <lho@amcc.com>
8 *
9 * This program is free software; you can redistribute it and/or modify it
10 * under the terms of the GNU General Public License as published by the Free
11 * Software Foundation; either version 2 of the License, or (at your option)
12 * any later version.
13 *
14 */
15
16#include <crypto/internal/hash.h>
17#include <crypto/scatterwalk.h>
18#include <linux/err.h>
19#include <linux/kernel.h>
20#include <linux/module.h>
21#include <linux/sched.h>
22#include <linux/slab.h>
23#include <linux/seq_file.h>
24#include <linux/cryptouser.h>
25#include <net/netlink.h>
26
27#include "internal.h"
28
29struct ahash_request_priv {
30	crypto_completion_t complete;
31	void *data;
32	u8 *result;
33	void *ubuf[] CRYPTO_MINALIGN_ATTR;
34};
35
36static inline struct ahash_alg *crypto_ahash_alg(struct crypto_ahash *hash)
37{
38	return container_of(crypto_hash_alg_common(hash), struct ahash_alg,
39			    halg);
40}
41
42static int hash_walk_next(struct crypto_hash_walk *walk)
43{
44	unsigned int alignmask = walk->alignmask;
45	unsigned int offset = walk->offset;
46	unsigned int nbytes = min(walk->entrylen,
47				  ((unsigned int)(PAGE_SIZE)) - offset);
48
49	walk->data = kmap_atomic(walk->pg);
50	walk->data += offset;
51
52	if (offset & alignmask) {
53		unsigned int unaligned = alignmask + 1 - (offset & alignmask);
54		if (nbytes > unaligned)
55			nbytes = unaligned;
56	}
57
58	walk->entrylen -= nbytes;
59	return nbytes;
60}
61
62static int hash_walk_new_entry(struct crypto_hash_walk *walk)
63{
64	struct scatterlist *sg;
65
66	sg = walk->sg;
67	walk->pg = sg_page(sg);
68	walk->offset = sg->offset;
69	walk->entrylen = sg->length;
70
71	if (walk->entrylen > walk->total)
72		walk->entrylen = walk->total;
73	walk->total -= walk->entrylen;
74
75	return hash_walk_next(walk);
76}
77
78int crypto_hash_walk_done(struct crypto_hash_walk *walk, int err)
79{
80	unsigned int alignmask = walk->alignmask;
81	unsigned int nbytes = walk->entrylen;
82
83	walk->data -= walk->offset;
84
85	if (nbytes && walk->offset & alignmask && !err) {
86		walk->offset = ALIGN(walk->offset, alignmask + 1);
87		walk->data += walk->offset;
88
89		nbytes = min(nbytes,
90			     ((unsigned int)(PAGE_SIZE)) - walk->offset);
91		walk->entrylen -= nbytes;
92
93		return nbytes;
94	}
95
96	kunmap_atomic(walk->data);
97	crypto_yield(walk->flags);
98
99	if (err)
100		return err;
101
102	if (nbytes) {
103		walk->offset = 0;
104		walk->pg++;
105		return hash_walk_next(walk);
106	}
107
108	if (!walk->total)
109		return 0;
110
111	walk->sg = scatterwalk_sg_next(walk->sg);
112
113	return hash_walk_new_entry(walk);
114}
115EXPORT_SYMBOL_GPL(crypto_hash_walk_done);
116
117int crypto_hash_walk_first(struct ahash_request *req,
118			   struct crypto_hash_walk *walk)
119{
120	walk->total = req->nbytes;
121
122	if (!walk->total)
123		return 0;
124
125	walk->alignmask = crypto_ahash_alignmask(crypto_ahash_reqtfm(req));
126	walk->sg = req->src;
127	walk->flags = req->base.flags;
128
129	return hash_walk_new_entry(walk);
130}
131EXPORT_SYMBOL_GPL(crypto_hash_walk_first);
132
133int crypto_hash_walk_first_compat(struct hash_desc *hdesc,
134				  struct crypto_hash_walk *walk,
135				  struct scatterlist *sg, unsigned int len)
136{
137	walk->total = len;
138
139	if (!walk->total)
140		return 0;
141
142	walk->alignmask = crypto_hash_alignmask(hdesc->tfm);
143	walk->sg = sg;
144	walk->flags = hdesc->flags;
145
146	return hash_walk_new_entry(walk);
147}
148
149static int ahash_setkey_unaligned(struct crypto_ahash *tfm, const u8 *key,
150				unsigned int keylen)
151{
152	unsigned long alignmask = crypto_ahash_alignmask(tfm);
153	int ret;
154	u8 *buffer, *alignbuffer;
155	unsigned long absize;
156
157	absize = keylen + alignmask;
158	buffer = kmalloc(absize, GFP_KERNEL);
159	if (!buffer)
160		return -ENOMEM;
161
162	alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
163	memcpy(alignbuffer, key, keylen);
164	ret = tfm->setkey(tfm, alignbuffer, keylen);
165	kzfree(buffer);
166	return ret;
167}
168
169int crypto_ahash_setkey(struct crypto_ahash *tfm, const u8 *key,
170			unsigned int keylen)
171{
172	unsigned long alignmask = crypto_ahash_alignmask(tfm);
173
174	if ((unsigned long)key & alignmask)
175		return ahash_setkey_unaligned(tfm, key, keylen);
176
177	return tfm->setkey(tfm, key, keylen);
178}
179EXPORT_SYMBOL_GPL(crypto_ahash_setkey);
180
181static int ahash_nosetkey(struct crypto_ahash *tfm, const u8 *key,
182			  unsigned int keylen)
183{
184	return -ENOSYS;
185}
186
187static inline unsigned int ahash_align_buffer_size(unsigned len,
188						   unsigned long mask)
189{
190	return len + (mask & ~(crypto_tfm_ctx_alignment() - 1));
191}
192
193static void ahash_op_unaligned_finish(struct ahash_request *req, int err)
194{
195	struct ahash_request_priv *priv = req->priv;
196
197	if (err == -EINPROGRESS)
198		return;
199
200	if (!err)
201		memcpy(priv->result, req->result,
202		       crypto_ahash_digestsize(crypto_ahash_reqtfm(req)));
203
204	kzfree(priv);
205}
206
207static void ahash_op_unaligned_done(struct crypto_async_request *req, int err)
208{
209	struct ahash_request *areq = req->data;
210	struct ahash_request_priv *priv = areq->priv;
211	crypto_completion_t complete = priv->complete;
212	void *data = priv->data;
213
214	ahash_op_unaligned_finish(areq, err);
215
216	complete(data, err);
217}
218
219static int ahash_op_unaligned(struct ahash_request *req,
220			      int (*op)(struct ahash_request *))
221{
222	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
223	unsigned long alignmask = crypto_ahash_alignmask(tfm);
224	unsigned int ds = crypto_ahash_digestsize(tfm);
225	struct ahash_request_priv *priv;
226	int err;
227
228	priv = kmalloc(sizeof(*priv) + ahash_align_buffer_size(ds, alignmask),
229		       (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ?
230		       GFP_KERNEL : GFP_ATOMIC);
231	if (!priv)
232		return -ENOMEM;
233
234	priv->result = req->result;
235	priv->complete = req->base.complete;
236	priv->data = req->base.data;
237
238	req->result = PTR_ALIGN((u8 *)priv->ubuf, alignmask + 1);
239	req->base.complete = ahash_op_unaligned_done;
240	req->base.data = req;
241	req->priv = priv;
242
243	err = op(req);
244	ahash_op_unaligned_finish(req, err);
245
246	return err;
247}
248
249static int crypto_ahash_op(struct ahash_request *req,
250			   int (*op)(struct ahash_request *))
251{
252	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
253	unsigned long alignmask = crypto_ahash_alignmask(tfm);
254
255	if ((unsigned long)req->result & alignmask)
256		return ahash_op_unaligned(req, op);
257
258	return op(req);
259}
260
261int crypto_ahash_final(struct ahash_request *req)
262{
263	return crypto_ahash_op(req, crypto_ahash_reqtfm(req)->final);
264}
265EXPORT_SYMBOL_GPL(crypto_ahash_final);
266
267int crypto_ahash_finup(struct ahash_request *req)
268{
269	return crypto_ahash_op(req, crypto_ahash_reqtfm(req)->finup);
270}
271EXPORT_SYMBOL_GPL(crypto_ahash_finup);
272
273int crypto_ahash_digest(struct ahash_request *req)
274{
275	return crypto_ahash_op(req, crypto_ahash_reqtfm(req)->digest);
276}
277EXPORT_SYMBOL_GPL(crypto_ahash_digest);
278
279static void ahash_def_finup_finish2(struct ahash_request *req, int err)
280{
281	struct ahash_request_priv *priv = req->priv;
282
283	if (err == -EINPROGRESS)
284		return;
285
286	if (!err)
287		memcpy(priv->result, req->result,
288		       crypto_ahash_digestsize(crypto_ahash_reqtfm(req)));
289
290	kzfree(priv);
291}
292
293static void ahash_def_finup_done2(struct crypto_async_request *req, int err)
294{
295	struct ahash_request *areq = req->data;
296	struct ahash_request_priv *priv = areq->priv;
297	crypto_completion_t complete = priv->complete;
298	void *data = priv->data;
299
300	ahash_def_finup_finish2(areq, err);
301
302	complete(data, err);
303}
304
305static int ahash_def_finup_finish1(struct ahash_request *req, int err)
306{
307	if (err)
308		goto out;
309
310	req->base.complete = ahash_def_finup_done2;
311	req->base.flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
312	err = crypto_ahash_reqtfm(req)->final(req);
313
314out:
315	ahash_def_finup_finish2(req, err);
316	return err;
317}
318
319static void ahash_def_finup_done1(struct crypto_async_request *req, int err)
320{
321	struct ahash_request *areq = req->data;
322	struct ahash_request_priv *priv = areq->priv;
323	crypto_completion_t complete = priv->complete;
324	void *data = priv->data;
325
326	err = ahash_def_finup_finish1(areq, err);
327
328	complete(data, err);
329}
330
331static int ahash_def_finup(struct ahash_request *req)
332{
333	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
334	unsigned long alignmask = crypto_ahash_alignmask(tfm);
335	unsigned int ds = crypto_ahash_digestsize(tfm);
336	struct ahash_request_priv *priv;
337
338	priv = kmalloc(sizeof(*priv) + ahash_align_buffer_size(ds, alignmask),
339		       (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ?
340		       GFP_KERNEL : GFP_ATOMIC);
341	if (!priv)
342		return -ENOMEM;
343
344	priv->result = req->result;
345	priv->complete = req->base.complete;
346	priv->data = req->base.data;
347
348	req->result = PTR_ALIGN((u8 *)priv->ubuf, alignmask + 1);
349	req->base.complete = ahash_def_finup_done1;
350	req->base.data = req;
351	req->priv = priv;
352
353	return ahash_def_finup_finish1(req, tfm->update(req));
354}
355
356static int ahash_no_export(struct ahash_request *req, void *out)
357{
358	return -ENOSYS;
359}
360
361static int ahash_no_import(struct ahash_request *req, const void *in)
362{
363	return -ENOSYS;
364}
365
366static int crypto_ahash_init_tfm(struct crypto_tfm *tfm)
367{
368	struct crypto_ahash *hash = __crypto_ahash_cast(tfm);
369	struct ahash_alg *alg = crypto_ahash_alg(hash);
370
371	hash->setkey = ahash_nosetkey;
372	hash->export = ahash_no_export;
373	hash->import = ahash_no_import;
374
375	if (tfm->__crt_alg->cra_type != &crypto_ahash_type)
376		return crypto_init_shash_ops_async(tfm);
377
378	hash->init = alg->init;
379	hash->update = alg->update;
380	hash->final = alg->final;
381	hash->finup = alg->finup ?: ahash_def_finup;
382	hash->digest = alg->digest;
383
384	if (alg->setkey)
385		hash->setkey = alg->setkey;
386	if (alg->export)
387		hash->export = alg->export;
388	if (alg->import)
389		hash->import = alg->import;
390
391	return 0;
392}
393
394static unsigned int crypto_ahash_extsize(struct crypto_alg *alg)
395{
396	if (alg->cra_type == &crypto_ahash_type)
397		return alg->cra_ctxsize;
398
399	return sizeof(struct crypto_shash *);
400}
401
402#ifdef CONFIG_NET
403static int crypto_ahash_report(struct sk_buff *skb, struct crypto_alg *alg)
404{
405	struct crypto_report_hash rhash;
406
407	strncpy(rhash.type, "ahash", sizeof(rhash.type));
408
409	rhash.blocksize = alg->cra_blocksize;
410	rhash.digestsize = __crypto_hash_alg_common(alg)->digestsize;
411
412	if (nla_put(skb, CRYPTOCFGA_REPORT_HASH,
413		    sizeof(struct crypto_report_hash), &rhash))
414		goto nla_put_failure;
415	return 0;
416
417nla_put_failure:
418	return -EMSGSIZE;
419}
420#else
421static int crypto_ahash_report(struct sk_buff *skb, struct crypto_alg *alg)
422{
423	return -ENOSYS;
424}
425#endif
426
427static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg)
428	__attribute__ ((unused));
429static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg)
430{
431	seq_printf(m, "type         : ahash\n");
432	seq_printf(m, "async        : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
433					     "yes" : "no");
434	seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
435	seq_printf(m, "digestsize   : %u\n",
436		   __crypto_hash_alg_common(alg)->digestsize);
437}
438
439const struct crypto_type crypto_ahash_type = {
440	.extsize = crypto_ahash_extsize,
441	.init_tfm = crypto_ahash_init_tfm,
442#ifdef CONFIG_PROC_FS
443	.show = crypto_ahash_show,
444#endif
445	.report = crypto_ahash_report,
446	.maskclear = ~CRYPTO_ALG_TYPE_MASK,
447	.maskset = CRYPTO_ALG_TYPE_AHASH_MASK,
448	.type = CRYPTO_ALG_TYPE_AHASH,
449	.tfmsize = offsetof(struct crypto_ahash, base),
450};
451EXPORT_SYMBOL_GPL(crypto_ahash_type);
452
453struct crypto_ahash *crypto_alloc_ahash(const char *alg_name, u32 type,
454					u32 mask)
455{
456	return crypto_alloc_tfm(alg_name, &crypto_ahash_type, type, mask);
457}
458EXPORT_SYMBOL_GPL(crypto_alloc_ahash);
459
460static int ahash_prepare_alg(struct ahash_alg *alg)
461{
462	struct crypto_alg *base = &alg->halg.base;
463
464	if (alg->halg.digestsize > PAGE_SIZE / 8 ||
465	    alg->halg.statesize > PAGE_SIZE / 8)
466		return -EINVAL;
467
468	base->cra_type = &crypto_ahash_type;
469	base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
470	base->cra_flags |= CRYPTO_ALG_TYPE_AHASH;
471
472	return 0;
473}
474
475int crypto_register_ahash(struct ahash_alg *alg)
476{
477	struct crypto_alg *base = &alg->halg.base;
478	int err;
479
480	err = ahash_prepare_alg(alg);
481	if (err)
482		return err;
483
484	return crypto_register_alg(base);
485}
486EXPORT_SYMBOL_GPL(crypto_register_ahash);
487
488int crypto_unregister_ahash(struct ahash_alg *alg)
489{
490	return crypto_unregister_alg(&alg->halg.base);
491}
492EXPORT_SYMBOL_GPL(crypto_unregister_ahash);
493
494int ahash_register_instance(struct crypto_template *tmpl,
495			    struct ahash_instance *inst)
496{
497	int err;
498
499	err = ahash_prepare_alg(&inst->alg);
500	if (err)
501		return err;
502
503	return crypto_register_instance(tmpl, ahash_crypto_instance(inst));
504}
505EXPORT_SYMBOL_GPL(ahash_register_instance);
506
507void ahash_free_instance(struct crypto_instance *inst)
508{
509	crypto_drop_spawn(crypto_instance_ctx(inst));
510	kfree(ahash_instance(inst));
511}
512EXPORT_SYMBOL_GPL(ahash_free_instance);
513
514int crypto_init_ahash_spawn(struct crypto_ahash_spawn *spawn,
515			    struct hash_alg_common *alg,
516			    struct crypto_instance *inst)
517{
518	return crypto_init_spawn2(&spawn->base, &alg->base, inst,
519				  &crypto_ahash_type);
520}
521EXPORT_SYMBOL_GPL(crypto_init_ahash_spawn);
522
523struct hash_alg_common *ahash_attr_alg(struct rtattr *rta, u32 type, u32 mask)
524{
525	struct crypto_alg *alg;
526
527	alg = crypto_attr_alg2(rta, &crypto_ahash_type, type, mask);
528	return IS_ERR(alg) ? ERR_CAST(alg) : __crypto_hash_alg_common(alg);
529}
530EXPORT_SYMBOL_GPL(ahash_attr_alg);
531
532MODULE_LICENSE("GPL");
533MODULE_DESCRIPTION("Asynchronous cryptographic hash type");
534