1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * Asynchronous Cryptographic Hash operations.
5 * This is the asynchronous version of hash.c with notification of
6 * completion via a callback.
8 * Copyright (c) 2008 Loc Ho <lho@amcc.com>
11 #include <crypto/internal/hash.h>
12 #include <crypto/scatterwalk.h>
13 #include <linux/bug.h>
14 #include <linux/err.h>
15 #include <linux/kernel.h>
16 #include <linux/module.h>
17 #include <linux/sched.h>
18 #include <linux/slab.h>
19 #include <linux/seq_file.h>
20 #include <linux/cryptouser.h>
21 #include <linux/compiler.h>
22 #include <net/netlink.h>
26 static const struct crypto_type crypto_ahash_type;
28 struct ahash_request_priv {
29 crypto_completion_t complete;
33 void *ubuf[] CRYPTO_MINALIGN_ATTR;
36 static inline struct ahash_alg *crypto_ahash_alg(struct crypto_ahash *hash)
38 return container_of(crypto_hash_alg_common(hash), struct ahash_alg,
42 static int hash_walk_next(struct crypto_hash_walk *walk)
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);
49 if (walk->flags & CRYPTO_ALG_ASYNC)
50 walk->data = kmap(walk->pg);
52 walk->data = kmap_atomic(walk->pg);
55 if (offset & alignmask) {
56 unsigned int unaligned = alignmask + 1 - (offset & alignmask);
58 if (nbytes > unaligned)
62 walk->entrylen -= nbytes;
66 static int hash_walk_new_entry(struct crypto_hash_walk *walk)
68 struct scatterlist *sg;
71 walk->offset = sg->offset;
72 walk->pg = sg_page(walk->sg) + (walk->offset >> PAGE_SHIFT);
73 walk->offset = offset_in_page(walk->offset);
74 walk->entrylen = sg->length;
76 if (walk->entrylen > walk->total)
77 walk->entrylen = walk->total;
78 walk->total -= walk->entrylen;
80 return hash_walk_next(walk);
83 int crypto_hash_walk_done(struct crypto_hash_walk *walk, int err)
85 unsigned int alignmask = walk->alignmask;
87 walk->data -= walk->offset;
89 if (walk->entrylen && (walk->offset & alignmask) && !err) {
92 walk->offset = ALIGN(walk->offset, alignmask + 1);
93 nbytes = min(walk->entrylen,
94 (unsigned int)(PAGE_SIZE - walk->offset));
96 walk->entrylen -= nbytes;
97 walk->data += walk->offset;
102 if (walk->flags & CRYPTO_ALG_ASYNC)
105 kunmap_atomic(walk->data);
107 * The may sleep test only makes sense for sync users.
108 * Async users don't need to sleep here anyway.
110 crypto_yield(walk->flags);
116 if (walk->entrylen) {
119 return hash_walk_next(walk);
125 walk->sg = sg_next(walk->sg);
127 return hash_walk_new_entry(walk);
129 EXPORT_SYMBOL_GPL(crypto_hash_walk_done);
131 int crypto_hash_walk_first(struct ahash_request *req,
132 struct crypto_hash_walk *walk)
134 walk->total = req->nbytes;
141 walk->alignmask = crypto_ahash_alignmask(crypto_ahash_reqtfm(req));
143 walk->flags = req->base.flags & CRYPTO_TFM_REQ_MASK;
145 return hash_walk_new_entry(walk);
147 EXPORT_SYMBOL_GPL(crypto_hash_walk_first);
149 int crypto_ahash_walk_first(struct ahash_request *req,
150 struct crypto_hash_walk *walk)
152 walk->total = req->nbytes;
159 walk->alignmask = crypto_ahash_alignmask(crypto_ahash_reqtfm(req));
161 walk->flags = req->base.flags & CRYPTO_TFM_REQ_MASK;
162 walk->flags |= CRYPTO_ALG_ASYNC;
164 BUILD_BUG_ON(CRYPTO_TFM_REQ_MASK & CRYPTO_ALG_ASYNC);
166 return hash_walk_new_entry(walk);
168 EXPORT_SYMBOL_GPL(crypto_ahash_walk_first);
170 static int ahash_setkey_unaligned(struct crypto_ahash *tfm, const u8 *key,
173 unsigned long alignmask = crypto_ahash_alignmask(tfm);
175 u8 *buffer, *alignbuffer;
176 unsigned long absize;
178 absize = keylen + alignmask;
179 buffer = kmalloc(absize, GFP_KERNEL);
183 alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
184 memcpy(alignbuffer, key, keylen);
185 ret = tfm->setkey(tfm, alignbuffer, keylen);
190 static int ahash_nosetkey(struct crypto_ahash *tfm, const u8 *key,
196 static void ahash_set_needkey(struct crypto_ahash *tfm)
198 const struct hash_alg_common *alg = crypto_hash_alg_common(tfm);
200 if (tfm->setkey != ahash_nosetkey &&
201 !(alg->base.cra_flags & CRYPTO_ALG_OPTIONAL_KEY))
202 crypto_ahash_set_flags(tfm, CRYPTO_TFM_NEED_KEY);
205 int crypto_ahash_setkey(struct crypto_ahash *tfm, const u8 *key,
208 unsigned long alignmask = crypto_ahash_alignmask(tfm);
211 if ((unsigned long)key & alignmask)
212 err = ahash_setkey_unaligned(tfm, key, keylen);
214 err = tfm->setkey(tfm, key, keylen);
217 ahash_set_needkey(tfm);
221 crypto_ahash_clear_flags(tfm, CRYPTO_TFM_NEED_KEY);
224 EXPORT_SYMBOL_GPL(crypto_ahash_setkey);
226 static inline unsigned int ahash_align_buffer_size(unsigned len,
229 return len + (mask & ~(crypto_tfm_ctx_alignment() - 1));
232 static int ahash_save_req(struct ahash_request *req, crypto_completion_t cplt)
234 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
235 unsigned long alignmask = crypto_ahash_alignmask(tfm);
236 unsigned int ds = crypto_ahash_digestsize(tfm);
237 struct ahash_request_priv *priv;
239 priv = kmalloc(sizeof(*priv) + ahash_align_buffer_size(ds, alignmask),
240 (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ?
241 GFP_KERNEL : GFP_ATOMIC);
246 * WARNING: Voodoo programming below!
248 * The code below is obscure and hard to understand, thus explanation
249 * is necessary. See include/crypto/hash.h and include/linux/crypto.h
250 * to understand the layout of structures used here!
252 * The code here will replace portions of the ORIGINAL request with
253 * pointers to new code and buffers so the hashing operation can store
254 * the result in aligned buffer. We will call the modified request
255 * an ADJUSTED request.
257 * The newly mangled request will look as such:
260 * .result = ADJUSTED[new aligned buffer]
261 * .base.complete = ADJUSTED[pointer to completion function]
262 * .base.data = ADJUSTED[*req (pointer to self)]
263 * .priv = ADJUSTED[new priv] {
264 * .result = ORIGINAL(result)
265 * .complete = ORIGINAL(base.complete)
266 * .data = ORIGINAL(base.data)
270 priv->result = req->result;
271 priv->complete = req->base.complete;
272 priv->data = req->base.data;
273 priv->flags = req->base.flags;
276 * WARNING: We do not backup req->priv here! The req->priv
277 * is for internal use of the Crypto API and the
278 * user must _NOT_ _EVER_ depend on it's content!
281 req->result = PTR_ALIGN((u8 *)priv->ubuf, alignmask + 1);
282 req->base.complete = cplt;
283 req->base.data = req;
289 static void ahash_restore_req(struct ahash_request *req, int err)
291 struct ahash_request_priv *priv = req->priv;
294 memcpy(priv->result, req->result,
295 crypto_ahash_digestsize(crypto_ahash_reqtfm(req)));
297 /* Restore the original crypto request. */
298 req->result = priv->result;
300 ahash_request_set_callback(req, priv->flags,
301 priv->complete, priv->data);
304 /* Free the req->priv.priv from the ADJUSTED request. */
308 static void ahash_notify_einprogress(struct ahash_request *req)
310 struct ahash_request_priv *priv = req->priv;
311 struct crypto_async_request oreq;
313 oreq.data = priv->data;
315 priv->complete(&oreq, -EINPROGRESS);
318 static void ahash_op_unaligned_done(struct crypto_async_request *req, int err)
320 struct ahash_request *areq = req->data;
322 if (err == -EINPROGRESS) {
323 ahash_notify_einprogress(areq);
328 * Restore the original request, see ahash_op_unaligned() for what
331 * The "struct ahash_request *req" here is in fact the "req.base"
332 * from the ADJUSTED request from ahash_op_unaligned(), thus as it
333 * is a pointer to self, it is also the ADJUSTED "req" .
336 /* First copy req->result into req->priv.result */
337 ahash_restore_req(areq, err);
339 /* Complete the ORIGINAL request. */
340 areq->base.complete(&areq->base, err);
343 static int ahash_op_unaligned(struct ahash_request *req,
344 int (*op)(struct ahash_request *))
348 err = ahash_save_req(req, ahash_op_unaligned_done);
353 if (err == -EINPROGRESS || err == -EBUSY)
356 ahash_restore_req(req, err);
361 static int crypto_ahash_op(struct ahash_request *req,
362 int (*op)(struct ahash_request *))
364 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
365 unsigned long alignmask = crypto_ahash_alignmask(tfm);
367 if ((unsigned long)req->result & alignmask)
368 return ahash_op_unaligned(req, op);
373 int crypto_ahash_final(struct ahash_request *req)
375 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
376 struct crypto_alg *alg = tfm->base.__crt_alg;
377 unsigned int nbytes = req->nbytes;
380 crypto_stats_get(alg);
381 ret = crypto_ahash_op(req, crypto_ahash_reqtfm(req)->final);
382 crypto_stats_ahash_final(nbytes, ret, alg);
385 EXPORT_SYMBOL_GPL(crypto_ahash_final);
387 int crypto_ahash_finup(struct ahash_request *req)
389 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
390 struct crypto_alg *alg = tfm->base.__crt_alg;
391 unsigned int nbytes = req->nbytes;
394 crypto_stats_get(alg);
395 ret = crypto_ahash_op(req, crypto_ahash_reqtfm(req)->finup);
396 crypto_stats_ahash_final(nbytes, ret, alg);
399 EXPORT_SYMBOL_GPL(crypto_ahash_finup);
401 int crypto_ahash_digest(struct ahash_request *req)
403 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
404 struct crypto_alg *alg = tfm->base.__crt_alg;
405 unsigned int nbytes = req->nbytes;
408 crypto_stats_get(alg);
409 if (crypto_ahash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
412 ret = crypto_ahash_op(req, tfm->digest);
413 crypto_stats_ahash_final(nbytes, ret, alg);
416 EXPORT_SYMBOL_GPL(crypto_ahash_digest);
418 static void ahash_def_finup_done2(struct crypto_async_request *req, int err)
420 struct ahash_request *areq = req->data;
422 if (err == -EINPROGRESS)
425 ahash_restore_req(areq, err);
427 areq->base.complete(&areq->base, err);
430 static int ahash_def_finup_finish1(struct ahash_request *req, int err)
435 req->base.complete = ahash_def_finup_done2;
437 err = crypto_ahash_reqtfm(req)->final(req);
438 if (err == -EINPROGRESS || err == -EBUSY)
442 ahash_restore_req(req, err);
446 static void ahash_def_finup_done1(struct crypto_async_request *req, int err)
448 struct ahash_request *areq = req->data;
450 if (err == -EINPROGRESS) {
451 ahash_notify_einprogress(areq);
455 areq->base.flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
457 err = ahash_def_finup_finish1(areq, err);
461 areq->base.complete(&areq->base, err);
464 static int ahash_def_finup(struct ahash_request *req)
466 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
469 err = ahash_save_req(req, ahash_def_finup_done1);
473 err = tfm->update(req);
474 if (err == -EINPROGRESS || err == -EBUSY)
477 return ahash_def_finup_finish1(req, err);
480 static int crypto_ahash_init_tfm(struct crypto_tfm *tfm)
482 struct crypto_ahash *hash = __crypto_ahash_cast(tfm);
483 struct ahash_alg *alg = crypto_ahash_alg(hash);
485 hash->setkey = ahash_nosetkey;
487 if (tfm->__crt_alg->cra_type != &crypto_ahash_type)
488 return crypto_init_shash_ops_async(tfm);
490 hash->init = alg->init;
491 hash->update = alg->update;
492 hash->final = alg->final;
493 hash->finup = alg->finup ?: ahash_def_finup;
494 hash->digest = alg->digest;
495 hash->export = alg->export;
496 hash->import = alg->import;
499 hash->setkey = alg->setkey;
500 ahash_set_needkey(hash);
506 static unsigned int crypto_ahash_extsize(struct crypto_alg *alg)
508 if (alg->cra_type != &crypto_ahash_type)
509 return sizeof(struct crypto_shash *);
511 return crypto_alg_extsize(alg);
514 static void crypto_ahash_free_instance(struct crypto_instance *inst)
516 struct ahash_instance *ahash = ahash_instance(inst);
522 static int crypto_ahash_report(struct sk_buff *skb, struct crypto_alg *alg)
524 struct crypto_report_hash rhash;
526 memset(&rhash, 0, sizeof(rhash));
528 strscpy(rhash.type, "ahash", sizeof(rhash.type));
530 rhash.blocksize = alg->cra_blocksize;
531 rhash.digestsize = __crypto_hash_alg_common(alg)->digestsize;
533 return nla_put(skb, CRYPTOCFGA_REPORT_HASH, sizeof(rhash), &rhash);
536 static int crypto_ahash_report(struct sk_buff *skb, struct crypto_alg *alg)
542 static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg)
544 static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg)
546 seq_printf(m, "type : ahash\n");
547 seq_printf(m, "async : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
549 seq_printf(m, "blocksize : %u\n", alg->cra_blocksize);
550 seq_printf(m, "digestsize : %u\n",
551 __crypto_hash_alg_common(alg)->digestsize);
554 static const struct crypto_type crypto_ahash_type = {
555 .extsize = crypto_ahash_extsize,
556 .init_tfm = crypto_ahash_init_tfm,
557 .free = crypto_ahash_free_instance,
558 #ifdef CONFIG_PROC_FS
559 .show = crypto_ahash_show,
561 .report = crypto_ahash_report,
562 .maskclear = ~CRYPTO_ALG_TYPE_MASK,
563 .maskset = CRYPTO_ALG_TYPE_AHASH_MASK,
564 .type = CRYPTO_ALG_TYPE_AHASH,
565 .tfmsize = offsetof(struct crypto_ahash, base),
568 int crypto_grab_ahash(struct crypto_ahash_spawn *spawn,
569 struct crypto_instance *inst,
570 const char *name, u32 type, u32 mask)
572 spawn->base.frontend = &crypto_ahash_type;
573 return crypto_grab_spawn(&spawn->base, inst, name, type, mask);
575 EXPORT_SYMBOL_GPL(crypto_grab_ahash);
577 struct crypto_ahash *crypto_alloc_ahash(const char *alg_name, u32 type,
580 return crypto_alloc_tfm(alg_name, &crypto_ahash_type, type, mask);
582 EXPORT_SYMBOL_GPL(crypto_alloc_ahash);
584 int crypto_has_ahash(const char *alg_name, u32 type, u32 mask)
586 return crypto_type_has_alg(alg_name, &crypto_ahash_type, type, mask);
588 EXPORT_SYMBOL_GPL(crypto_has_ahash);
590 static int ahash_prepare_alg(struct ahash_alg *alg)
592 struct crypto_alg *base = &alg->halg.base;
594 if (alg->halg.digestsize > HASH_MAX_DIGESTSIZE ||
595 alg->halg.statesize > HASH_MAX_STATESIZE ||
596 alg->halg.statesize == 0)
599 base->cra_type = &crypto_ahash_type;
600 base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
601 base->cra_flags |= CRYPTO_ALG_TYPE_AHASH;
606 int crypto_register_ahash(struct ahash_alg *alg)
608 struct crypto_alg *base = &alg->halg.base;
611 err = ahash_prepare_alg(alg);
615 return crypto_register_alg(base);
617 EXPORT_SYMBOL_GPL(crypto_register_ahash);
619 void crypto_unregister_ahash(struct ahash_alg *alg)
621 crypto_unregister_alg(&alg->halg.base);
623 EXPORT_SYMBOL_GPL(crypto_unregister_ahash);
625 int crypto_register_ahashes(struct ahash_alg *algs, int count)
629 for (i = 0; i < count; i++) {
630 ret = crypto_register_ahash(&algs[i]);
638 for (--i; i >= 0; --i)
639 crypto_unregister_ahash(&algs[i]);
643 EXPORT_SYMBOL_GPL(crypto_register_ahashes);
645 void crypto_unregister_ahashes(struct ahash_alg *algs, int count)
649 for (i = count - 1; i >= 0; --i)
650 crypto_unregister_ahash(&algs[i]);
652 EXPORT_SYMBOL_GPL(crypto_unregister_ahashes);
654 int ahash_register_instance(struct crypto_template *tmpl,
655 struct ahash_instance *inst)
659 if (WARN_ON(!inst->free))
662 err = ahash_prepare_alg(&inst->alg);
666 return crypto_register_instance(tmpl, ahash_crypto_instance(inst));
668 EXPORT_SYMBOL_GPL(ahash_register_instance);
670 bool crypto_hash_alg_has_setkey(struct hash_alg_common *halg)
672 struct crypto_alg *alg = &halg->base;
674 if (alg->cra_type != &crypto_ahash_type)
675 return crypto_shash_alg_has_setkey(__crypto_shash_alg(alg));
677 return __crypto_ahash_alg(alg)->setkey != NULL;
679 EXPORT_SYMBOL_GPL(crypto_hash_alg_has_setkey);
681 MODULE_LICENSE("GPL");
682 MODULE_DESCRIPTION("Asynchronous cryptographic hash type");