2 * Asynchronous Cryptographic Hash operations.
4 * This is the asynchronous version of hash.c with notification of
5 * completion via a callback.
7 * Copyright (c) 2008 Loc Ho <lho@amcc.com>
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)
16 #include <crypto/internal/hash.h>
17 #include <crypto/scatterwalk.h>
18 #include <linux/bug.h>
19 #include <linux/err.h>
20 #include <linux/kernel.h>
21 #include <linux/module.h>
22 #include <linux/sched.h>
23 #include <linux/slab.h>
24 #include <linux/seq_file.h>
25 #include <linux/cryptouser.h>
26 #include <net/netlink.h>
30 struct ahash_request_priv {
31 crypto_completion_t complete;
35 void *ubuf[] CRYPTO_MINALIGN_ATTR;
38 static inline struct ahash_alg *crypto_ahash_alg(struct crypto_ahash *hash)
40 return container_of(crypto_hash_alg_common(hash), struct ahash_alg,
44 static int hash_walk_next(struct crypto_hash_walk *walk)
46 unsigned int alignmask = walk->alignmask;
47 unsigned int offset = walk->offset;
48 unsigned int nbytes = min(walk->entrylen,
49 ((unsigned int)(PAGE_SIZE)) - offset);
51 if (walk->flags & CRYPTO_ALG_ASYNC)
52 walk->data = kmap(walk->pg);
54 walk->data = kmap_atomic(walk->pg);
57 if (offset & alignmask) {
58 unsigned int unaligned = alignmask + 1 - (offset & alignmask);
60 if (nbytes > unaligned)
64 walk->entrylen -= nbytes;
68 static int hash_walk_new_entry(struct crypto_hash_walk *walk)
70 struct scatterlist *sg;
73 walk->offset = sg->offset;
74 walk->pg = sg_page(walk->sg) + (walk->offset >> PAGE_SHIFT);
75 walk->offset = offset_in_page(walk->offset);
76 walk->entrylen = sg->length;
78 if (walk->entrylen > walk->total)
79 walk->entrylen = walk->total;
80 walk->total -= walk->entrylen;
82 return hash_walk_next(walk);
85 int crypto_hash_walk_done(struct crypto_hash_walk *walk, int err)
87 unsigned int alignmask = walk->alignmask;
88 unsigned int nbytes = walk->entrylen;
90 walk->data -= walk->offset;
92 if (nbytes && walk->offset & alignmask && !err) {
93 walk->offset = ALIGN(walk->offset, alignmask + 1);
95 ((unsigned int)(PAGE_SIZE)) - walk->offset);
96 walk->entrylen -= nbytes;
99 walk->data += walk->offset;
104 if (walk->flags & CRYPTO_ALG_ASYNC)
107 kunmap_atomic(walk->data);
109 * The may sleep test only makes sense for sync users.
110 * Async users don't need to sleep here anyway.
112 crypto_yield(walk->flags);
121 return hash_walk_next(walk);
127 walk->sg = sg_next(walk->sg);
129 return hash_walk_new_entry(walk);
131 EXPORT_SYMBOL_GPL(crypto_hash_walk_done);
133 int crypto_hash_walk_first(struct ahash_request *req,
134 struct crypto_hash_walk *walk)
136 walk->total = req->nbytes;
143 walk->alignmask = crypto_ahash_alignmask(crypto_ahash_reqtfm(req));
145 walk->flags = req->base.flags & CRYPTO_TFM_REQ_MASK;
147 return hash_walk_new_entry(walk);
149 EXPORT_SYMBOL_GPL(crypto_hash_walk_first);
151 int crypto_ahash_walk_first(struct ahash_request *req,
152 struct crypto_hash_walk *walk)
154 walk->total = req->nbytes;
161 walk->alignmask = crypto_ahash_alignmask(crypto_ahash_reqtfm(req));
163 walk->flags = req->base.flags & CRYPTO_TFM_REQ_MASK;
164 walk->flags |= CRYPTO_ALG_ASYNC;
166 BUILD_BUG_ON(CRYPTO_TFM_REQ_MASK & CRYPTO_ALG_ASYNC);
168 return hash_walk_new_entry(walk);
170 EXPORT_SYMBOL_GPL(crypto_ahash_walk_first);
172 int crypto_hash_walk_first_compat(struct hash_desc *hdesc,
173 struct crypto_hash_walk *walk,
174 struct scatterlist *sg, unsigned int len)
183 walk->alignmask = crypto_hash_alignmask(hdesc->tfm);
185 walk->flags = hdesc->flags & CRYPTO_TFM_REQ_MASK;
187 return hash_walk_new_entry(walk);
190 static int ahash_setkey_unaligned(struct crypto_ahash *tfm, const u8 *key,
193 unsigned long alignmask = crypto_ahash_alignmask(tfm);
195 u8 *buffer, *alignbuffer;
196 unsigned long absize;
198 absize = keylen + alignmask;
199 buffer = kmalloc(absize, GFP_KERNEL);
203 alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
204 memcpy(alignbuffer, key, keylen);
205 ret = tfm->setkey(tfm, alignbuffer, keylen);
210 int crypto_ahash_setkey(struct crypto_ahash *tfm, const u8 *key,
213 unsigned long alignmask = crypto_ahash_alignmask(tfm);
215 if ((unsigned long)key & alignmask)
216 return ahash_setkey_unaligned(tfm, key, keylen);
218 return tfm->setkey(tfm, key, keylen);
220 EXPORT_SYMBOL_GPL(crypto_ahash_setkey);
222 static int ahash_nosetkey(struct crypto_ahash *tfm, const u8 *key,
228 static inline unsigned int ahash_align_buffer_size(unsigned len,
231 return len + (mask & ~(crypto_tfm_ctx_alignment() - 1));
234 static int ahash_save_req(struct ahash_request *req, crypto_completion_t cplt)
236 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
237 unsigned long alignmask = crypto_ahash_alignmask(tfm);
238 unsigned int ds = crypto_ahash_digestsize(tfm);
239 struct ahash_request_priv *priv;
241 priv = kmalloc(sizeof(*priv) + ahash_align_buffer_size(ds, alignmask),
242 (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ?
243 GFP_KERNEL : GFP_ATOMIC);
248 * WARNING: Voodoo programming below!
250 * The code below is obscure and hard to understand, thus explanation
251 * is necessary. See include/crypto/hash.h and include/linux/crypto.h
252 * to understand the layout of structures used here!
254 * The code here will replace portions of the ORIGINAL request with
255 * pointers to new code and buffers so the hashing operation can store
256 * the result in aligned buffer. We will call the modified request
257 * an ADJUSTED request.
259 * The newly mangled request will look as such:
262 * .result = ADJUSTED[new aligned buffer]
263 * .base.complete = ADJUSTED[pointer to completion function]
264 * .base.data = ADJUSTED[*req (pointer to self)]
265 * .priv = ADJUSTED[new priv] {
266 * .result = ORIGINAL(result)
267 * .complete = ORIGINAL(base.complete)
268 * .data = ORIGINAL(base.data)
272 priv->result = req->result;
273 priv->complete = req->base.complete;
274 priv->data = req->base.data;
275 priv->flags = req->base.flags;
278 * WARNING: We do not backup req->priv here! The req->priv
279 * is for internal use of the Crypto API and the
280 * user must _NOT_ _EVER_ depend on it's content!
283 req->result = PTR_ALIGN((u8 *)priv->ubuf, alignmask + 1);
284 req->base.complete = cplt;
285 req->base.data = req;
291 static void ahash_restore_req(struct ahash_request *req, int err)
293 struct ahash_request_priv *priv = req->priv;
296 memcpy(priv->result, req->result,
297 crypto_ahash_digestsize(crypto_ahash_reqtfm(req)));
299 /* Restore the original crypto request. */
300 req->result = priv->result;
302 ahash_request_set_callback(req, priv->flags,
303 priv->complete, priv->data);
306 /* Free the req->priv.priv from the ADJUSTED request. */
310 static void ahash_notify_einprogress(struct ahash_request *req)
312 struct ahash_request_priv *priv = req->priv;
313 struct crypto_async_request oreq;
315 oreq.data = priv->data;
317 priv->complete(&oreq, -EINPROGRESS);
320 static void ahash_op_unaligned_done(struct crypto_async_request *req, int err)
322 struct ahash_request *areq = req->data;
324 if (err == -EINPROGRESS) {
325 ahash_notify_einprogress(areq);
330 * Restore the original request, see ahash_op_unaligned() for what
333 * The "struct ahash_request *req" here is in fact the "req.base"
334 * from the ADJUSTED request from ahash_op_unaligned(), thus as it
335 * is a pointer to self, it is also the ADJUSTED "req" .
338 /* First copy req->result into req->priv.result */
339 ahash_restore_req(areq, err);
341 /* Complete the ORIGINAL request. */
342 areq->base.complete(&areq->base, err);
345 static int ahash_op_unaligned(struct ahash_request *req,
346 int (*op)(struct ahash_request *))
350 err = ahash_save_req(req, ahash_op_unaligned_done);
355 if (err == -EINPROGRESS ||
356 (err == -EBUSY && (ahash_request_flags(req) &
357 CRYPTO_TFM_REQ_MAY_BACKLOG)))
360 ahash_restore_req(req, err);
365 static int crypto_ahash_op(struct ahash_request *req,
366 int (*op)(struct ahash_request *))
368 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
369 unsigned long alignmask = crypto_ahash_alignmask(tfm);
371 if ((unsigned long)req->result & alignmask)
372 return ahash_op_unaligned(req, op);
377 int crypto_ahash_final(struct ahash_request *req)
379 return crypto_ahash_op(req, crypto_ahash_reqtfm(req)->final);
381 EXPORT_SYMBOL_GPL(crypto_ahash_final);
383 int crypto_ahash_finup(struct ahash_request *req)
385 return crypto_ahash_op(req, crypto_ahash_reqtfm(req)->finup);
387 EXPORT_SYMBOL_GPL(crypto_ahash_finup);
389 int crypto_ahash_digest(struct ahash_request *req)
391 return crypto_ahash_op(req, crypto_ahash_reqtfm(req)->digest);
393 EXPORT_SYMBOL_GPL(crypto_ahash_digest);
395 static void ahash_def_finup_done2(struct crypto_async_request *req, int err)
397 struct ahash_request *areq = req->data;
399 if (err == -EINPROGRESS)
402 ahash_restore_req(areq, err);
404 areq->base.complete(&areq->base, err);
407 static int ahash_def_finup_finish1(struct ahash_request *req, int err)
412 req->base.complete = ahash_def_finup_done2;
414 err = crypto_ahash_reqtfm(req)->final(req);
415 if (err == -EINPROGRESS ||
416 (err == -EBUSY && (ahash_request_flags(req) &
417 CRYPTO_TFM_REQ_MAY_BACKLOG)))
421 ahash_restore_req(req, err);
425 static void ahash_def_finup_done1(struct crypto_async_request *req, int err)
427 struct ahash_request *areq = req->data;
429 if (err == -EINPROGRESS) {
430 ahash_notify_einprogress(areq);
434 areq->base.flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
436 err = ahash_def_finup_finish1(areq, err);
440 areq->base.complete(&areq->base, err);
443 static int ahash_def_finup(struct ahash_request *req)
445 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
448 err = ahash_save_req(req, ahash_def_finup_done1);
452 err = tfm->update(req);
453 if (err == -EINPROGRESS ||
454 (err == -EBUSY && (ahash_request_flags(req) &
455 CRYPTO_TFM_REQ_MAY_BACKLOG)))
458 return ahash_def_finup_finish1(req, err);
461 static int ahash_no_export(struct ahash_request *req, void *out)
466 static int ahash_no_import(struct ahash_request *req, const void *in)
471 static int crypto_ahash_init_tfm(struct crypto_tfm *tfm)
473 struct crypto_ahash *hash = __crypto_ahash_cast(tfm);
474 struct ahash_alg *alg = crypto_ahash_alg(hash);
476 hash->setkey = ahash_nosetkey;
477 hash->has_setkey = false;
478 hash->export = ahash_no_export;
479 hash->import = ahash_no_import;
481 if (tfm->__crt_alg->cra_type != &crypto_ahash_type)
482 return crypto_init_shash_ops_async(tfm);
484 hash->init = alg->init;
485 hash->update = alg->update;
486 hash->final = alg->final;
487 hash->finup = alg->finup ?: ahash_def_finup;
488 hash->digest = alg->digest;
491 hash->setkey = alg->setkey;
492 hash->has_setkey = true;
495 hash->export = alg->export;
497 hash->import = alg->import;
502 static unsigned int crypto_ahash_extsize(struct crypto_alg *alg)
504 if (alg->cra_type == &crypto_ahash_type)
505 return alg->cra_ctxsize;
507 return sizeof(struct crypto_shash *);
511 static int crypto_ahash_report(struct sk_buff *skb, struct crypto_alg *alg)
513 struct crypto_report_hash rhash;
515 strncpy(rhash.type, "ahash", sizeof(rhash.type));
517 rhash.blocksize = alg->cra_blocksize;
518 rhash.digestsize = __crypto_hash_alg_common(alg)->digestsize;
520 if (nla_put(skb, CRYPTOCFGA_REPORT_HASH,
521 sizeof(struct crypto_report_hash), &rhash))
522 goto nla_put_failure;
529 static int crypto_ahash_report(struct sk_buff *skb, struct crypto_alg *alg)
535 static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg)
536 __attribute__ ((unused));
537 static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg)
539 seq_printf(m, "type : ahash\n");
540 seq_printf(m, "async : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
542 seq_printf(m, "blocksize : %u\n", alg->cra_blocksize);
543 seq_printf(m, "digestsize : %u\n",
544 __crypto_hash_alg_common(alg)->digestsize);
547 const struct crypto_type crypto_ahash_type = {
548 .extsize = crypto_ahash_extsize,
549 .init_tfm = crypto_ahash_init_tfm,
550 #ifdef CONFIG_PROC_FS
551 .show = crypto_ahash_show,
553 .report = crypto_ahash_report,
554 .maskclear = ~CRYPTO_ALG_TYPE_MASK,
555 .maskset = CRYPTO_ALG_TYPE_AHASH_MASK,
556 .type = CRYPTO_ALG_TYPE_AHASH,
557 .tfmsize = offsetof(struct crypto_ahash, base),
559 EXPORT_SYMBOL_GPL(crypto_ahash_type);
561 struct crypto_ahash *crypto_alloc_ahash(const char *alg_name, u32 type,
564 return crypto_alloc_tfm(alg_name, &crypto_ahash_type, type, mask);
566 EXPORT_SYMBOL_GPL(crypto_alloc_ahash);
568 static int ahash_prepare_alg(struct ahash_alg *alg)
570 struct crypto_alg *base = &alg->halg.base;
572 if (alg->halg.digestsize > PAGE_SIZE / 8 ||
573 alg->halg.statesize > PAGE_SIZE / 8 ||
574 alg->halg.statesize == 0)
577 base->cra_type = &crypto_ahash_type;
578 base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
579 base->cra_flags |= CRYPTO_ALG_TYPE_AHASH;
584 int crypto_register_ahash(struct ahash_alg *alg)
586 struct crypto_alg *base = &alg->halg.base;
589 err = ahash_prepare_alg(alg);
593 return crypto_register_alg(base);
595 EXPORT_SYMBOL_GPL(crypto_register_ahash);
597 int crypto_unregister_ahash(struct ahash_alg *alg)
599 return crypto_unregister_alg(&alg->halg.base);
601 EXPORT_SYMBOL_GPL(crypto_unregister_ahash);
603 int ahash_register_instance(struct crypto_template *tmpl,
604 struct ahash_instance *inst)
608 err = ahash_prepare_alg(&inst->alg);
612 return crypto_register_instance(tmpl, ahash_crypto_instance(inst));
614 EXPORT_SYMBOL_GPL(ahash_register_instance);
616 void ahash_free_instance(struct crypto_instance *inst)
618 crypto_drop_spawn(crypto_instance_ctx(inst));
619 kfree(ahash_instance(inst));
621 EXPORT_SYMBOL_GPL(ahash_free_instance);
623 int crypto_init_ahash_spawn(struct crypto_ahash_spawn *spawn,
624 struct hash_alg_common *alg,
625 struct crypto_instance *inst)
627 return crypto_init_spawn2(&spawn->base, &alg->base, inst,
630 EXPORT_SYMBOL_GPL(crypto_init_ahash_spawn);
632 struct hash_alg_common *ahash_attr_alg(struct rtattr *rta, u32 type, u32 mask)
634 struct crypto_alg *alg;
636 alg = crypto_attr_alg2(rta, &crypto_ahash_type, type, mask);
637 return IS_ERR(alg) ? ERR_CAST(alg) : __crypto_hash_alg_common(alg);
639 EXPORT_SYMBOL_GPL(ahash_attr_alg);
641 bool crypto_hash_alg_has_setkey(struct hash_alg_common *halg)
643 struct crypto_alg *alg = &halg->base;
645 if (alg->cra_type != &crypto_ahash_type)
646 return crypto_shash_alg_has_setkey(__crypto_shash_alg(alg));
648 return __crypto_ahash_alg(alg)->setkey != NULL;
650 EXPORT_SYMBOL_GPL(crypto_hash_alg_has_setkey);
652 MODULE_LICENSE("GPL");
653 MODULE_DESCRIPTION("Asynchronous cryptographic hash type");