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);
94 walk->data += walk->offset;
97 ((unsigned int)(PAGE_SIZE)) - walk->offset);
98 walk->entrylen -= nbytes;
103 if (walk->flags & CRYPTO_ALG_ASYNC)
106 kunmap_atomic(walk->data);
108 * The may sleep test only makes sense for sync users.
109 * Async users don't need to sleep here anyway.
111 crypto_yield(walk->flags);
120 return hash_walk_next(walk);
126 walk->sg = sg_next(walk->sg);
128 return hash_walk_new_entry(walk);
130 EXPORT_SYMBOL_GPL(crypto_hash_walk_done);
132 int crypto_hash_walk_first(struct ahash_request *req,
133 struct crypto_hash_walk *walk)
135 walk->total = req->nbytes;
142 walk->alignmask = crypto_ahash_alignmask(crypto_ahash_reqtfm(req));
144 walk->flags = req->base.flags & CRYPTO_TFM_REQ_MASK;
146 return hash_walk_new_entry(walk);
148 EXPORT_SYMBOL_GPL(crypto_hash_walk_first);
150 int crypto_ahash_walk_first(struct ahash_request *req,
151 struct crypto_hash_walk *walk)
153 walk->total = req->nbytes;
160 walk->alignmask = crypto_ahash_alignmask(crypto_ahash_reqtfm(req));
162 walk->flags = req->base.flags & CRYPTO_TFM_REQ_MASK;
163 walk->flags |= CRYPTO_ALG_ASYNC;
165 BUILD_BUG_ON(CRYPTO_TFM_REQ_MASK & CRYPTO_ALG_ASYNC);
167 return hash_walk_new_entry(walk);
169 EXPORT_SYMBOL_GPL(crypto_ahash_walk_first);
171 int crypto_hash_walk_first_compat(struct hash_desc *hdesc,
172 struct crypto_hash_walk *walk,
173 struct scatterlist *sg, unsigned int len)
182 walk->alignmask = crypto_hash_alignmask(hdesc->tfm);
184 walk->flags = hdesc->flags & CRYPTO_TFM_REQ_MASK;
186 return hash_walk_new_entry(walk);
189 static int ahash_setkey_unaligned(struct crypto_ahash *tfm, const u8 *key,
192 unsigned long alignmask = crypto_ahash_alignmask(tfm);
194 u8 *buffer, *alignbuffer;
195 unsigned long absize;
197 absize = keylen + alignmask;
198 buffer = kmalloc(absize, GFP_KERNEL);
202 alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
203 memcpy(alignbuffer, key, keylen);
204 ret = tfm->setkey(tfm, alignbuffer, keylen);
209 int crypto_ahash_setkey(struct crypto_ahash *tfm, const u8 *key,
212 unsigned long alignmask = crypto_ahash_alignmask(tfm);
214 if ((unsigned long)key & alignmask)
215 return ahash_setkey_unaligned(tfm, key, keylen);
217 return tfm->setkey(tfm, key, keylen);
219 EXPORT_SYMBOL_GPL(crypto_ahash_setkey);
221 static int ahash_nosetkey(struct crypto_ahash *tfm, const u8 *key,
227 static inline unsigned int ahash_align_buffer_size(unsigned len,
230 return len + (mask & ~(crypto_tfm_ctx_alignment() - 1));
233 static int ahash_save_req(struct ahash_request *req, crypto_completion_t cplt)
235 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
236 unsigned long alignmask = crypto_ahash_alignmask(tfm);
237 unsigned int ds = crypto_ahash_digestsize(tfm);
238 struct ahash_request_priv *priv;
240 priv = kmalloc(sizeof(*priv) + ahash_align_buffer_size(ds, alignmask),
241 (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ?
242 GFP_KERNEL : GFP_ATOMIC);
247 * WARNING: Voodoo programming below!
249 * The code below is obscure and hard to understand, thus explanation
250 * is necessary. See include/crypto/hash.h and include/linux/crypto.h
251 * to understand the layout of structures used here!
253 * The code here will replace portions of the ORIGINAL request with
254 * pointers to new code and buffers so the hashing operation can store
255 * the result in aligned buffer. We will call the modified request
256 * an ADJUSTED request.
258 * The newly mangled request will look as such:
261 * .result = ADJUSTED[new aligned buffer]
262 * .base.complete = ADJUSTED[pointer to completion function]
263 * .base.data = ADJUSTED[*req (pointer to self)]
264 * .priv = ADJUSTED[new priv] {
265 * .result = ORIGINAL(result)
266 * .complete = ORIGINAL(base.complete)
267 * .data = ORIGINAL(base.data)
271 priv->result = req->result;
272 priv->complete = req->base.complete;
273 priv->data = req->base.data;
274 priv->flags = req->base.flags;
277 * WARNING: We do not backup req->priv here! The req->priv
278 * is for internal use of the Crypto API and the
279 * user must _NOT_ _EVER_ depend on it's content!
282 req->result = PTR_ALIGN((u8 *)priv->ubuf, alignmask + 1);
283 req->base.complete = cplt;
284 req->base.data = req;
290 static void ahash_restore_req(struct ahash_request *req, int err)
292 struct ahash_request_priv *priv = req->priv;
295 memcpy(priv->result, req->result,
296 crypto_ahash_digestsize(crypto_ahash_reqtfm(req)));
298 /* Restore the original crypto request. */
299 req->result = priv->result;
301 ahash_request_set_callback(req, priv->flags,
302 priv->complete, priv->data);
305 /* Free the req->priv.priv from the ADJUSTED request. */
309 static void ahash_notify_einprogress(struct ahash_request *req)
311 struct ahash_request_priv *priv = req->priv;
312 struct crypto_async_request oreq;
314 oreq.data = priv->data;
316 priv->complete(&oreq, -EINPROGRESS);
319 static void ahash_op_unaligned_done(struct crypto_async_request *req, int err)
321 struct ahash_request *areq = req->data;
323 if (err == -EINPROGRESS) {
324 ahash_notify_einprogress(areq);
329 * Restore the original request, see ahash_op_unaligned() for what
332 * The "struct ahash_request *req" here is in fact the "req.base"
333 * from the ADJUSTED request from ahash_op_unaligned(), thus as it
334 * is a pointer to self, it is also the ADJUSTED "req" .
337 /* First copy req->result into req->priv.result */
338 ahash_restore_req(areq, err);
340 /* Complete the ORIGINAL request. */
341 areq->base.complete(&areq->base, err);
344 static int ahash_op_unaligned(struct ahash_request *req,
345 int (*op)(struct ahash_request *))
349 err = ahash_save_req(req, ahash_op_unaligned_done);
354 if (err == -EINPROGRESS ||
355 (err == -EBUSY && (ahash_request_flags(req) &
356 CRYPTO_TFM_REQ_MAY_BACKLOG)))
359 ahash_restore_req(req, err);
364 static int crypto_ahash_op(struct ahash_request *req,
365 int (*op)(struct ahash_request *))
367 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
368 unsigned long alignmask = crypto_ahash_alignmask(tfm);
370 if ((unsigned long)req->result & alignmask)
371 return ahash_op_unaligned(req, op);
376 int crypto_ahash_final(struct ahash_request *req)
378 return crypto_ahash_op(req, crypto_ahash_reqtfm(req)->final);
380 EXPORT_SYMBOL_GPL(crypto_ahash_final);
382 int crypto_ahash_finup(struct ahash_request *req)
384 return crypto_ahash_op(req, crypto_ahash_reqtfm(req)->finup);
386 EXPORT_SYMBOL_GPL(crypto_ahash_finup);
388 int crypto_ahash_digest(struct ahash_request *req)
390 return crypto_ahash_op(req, crypto_ahash_reqtfm(req)->digest);
392 EXPORT_SYMBOL_GPL(crypto_ahash_digest);
394 static void ahash_def_finup_done2(struct crypto_async_request *req, int err)
396 struct ahash_request *areq = req->data;
398 if (err == -EINPROGRESS)
401 ahash_restore_req(areq, err);
403 areq->base.complete(&areq->base, err);
406 static int ahash_def_finup_finish1(struct ahash_request *req, int err)
411 req->base.complete = ahash_def_finup_done2;
413 err = crypto_ahash_reqtfm(req)->final(req);
414 if (err == -EINPROGRESS ||
415 (err == -EBUSY && (ahash_request_flags(req) &
416 CRYPTO_TFM_REQ_MAY_BACKLOG)))
420 ahash_restore_req(req, err);
424 static void ahash_def_finup_done1(struct crypto_async_request *req, int err)
426 struct ahash_request *areq = req->data;
428 if (err == -EINPROGRESS) {
429 ahash_notify_einprogress(areq);
433 areq->base.flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
435 err = ahash_def_finup_finish1(areq, err);
439 areq->base.complete(&areq->base, err);
442 static int ahash_def_finup(struct ahash_request *req)
444 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
447 err = ahash_save_req(req, ahash_def_finup_done1);
451 err = tfm->update(req);
452 if (err == -EINPROGRESS ||
453 (err == -EBUSY && (ahash_request_flags(req) &
454 CRYPTO_TFM_REQ_MAY_BACKLOG)))
457 return ahash_def_finup_finish1(req, err);
460 static int ahash_no_export(struct ahash_request *req, void *out)
465 static int ahash_no_import(struct ahash_request *req, const void *in)
470 static int crypto_ahash_init_tfm(struct crypto_tfm *tfm)
472 struct crypto_ahash *hash = __crypto_ahash_cast(tfm);
473 struct ahash_alg *alg = crypto_ahash_alg(hash);
475 hash->setkey = ahash_nosetkey;
476 hash->has_setkey = false;
477 hash->export = ahash_no_export;
478 hash->import = ahash_no_import;
480 if (tfm->__crt_alg->cra_type != &crypto_ahash_type)
481 return crypto_init_shash_ops_async(tfm);
483 hash->init = alg->init;
484 hash->update = alg->update;
485 hash->final = alg->final;
486 hash->finup = alg->finup ?: ahash_def_finup;
487 hash->digest = alg->digest;
490 hash->setkey = alg->setkey;
491 hash->has_setkey = true;
494 hash->export = alg->export;
496 hash->import = alg->import;
501 static unsigned int crypto_ahash_extsize(struct crypto_alg *alg)
503 if (alg->cra_type == &crypto_ahash_type)
504 return alg->cra_ctxsize;
506 return sizeof(struct crypto_shash *);
510 static int crypto_ahash_report(struct sk_buff *skb, struct crypto_alg *alg)
512 struct crypto_report_hash rhash;
514 strncpy(rhash.type, "ahash", sizeof(rhash.type));
516 rhash.blocksize = alg->cra_blocksize;
517 rhash.digestsize = __crypto_hash_alg_common(alg)->digestsize;
519 if (nla_put(skb, CRYPTOCFGA_REPORT_HASH,
520 sizeof(struct crypto_report_hash), &rhash))
521 goto nla_put_failure;
528 static int crypto_ahash_report(struct sk_buff *skb, struct crypto_alg *alg)
534 static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg)
535 __attribute__ ((unused));
536 static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg)
538 seq_printf(m, "type : ahash\n");
539 seq_printf(m, "async : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
541 seq_printf(m, "blocksize : %u\n", alg->cra_blocksize);
542 seq_printf(m, "digestsize : %u\n",
543 __crypto_hash_alg_common(alg)->digestsize);
546 const struct crypto_type crypto_ahash_type = {
547 .extsize = crypto_ahash_extsize,
548 .init_tfm = crypto_ahash_init_tfm,
549 #ifdef CONFIG_PROC_FS
550 .show = crypto_ahash_show,
552 .report = crypto_ahash_report,
553 .maskclear = ~CRYPTO_ALG_TYPE_MASK,
554 .maskset = CRYPTO_ALG_TYPE_AHASH_MASK,
555 .type = CRYPTO_ALG_TYPE_AHASH,
556 .tfmsize = offsetof(struct crypto_ahash, base),
558 EXPORT_SYMBOL_GPL(crypto_ahash_type);
560 struct crypto_ahash *crypto_alloc_ahash(const char *alg_name, u32 type,
563 return crypto_alloc_tfm(alg_name, &crypto_ahash_type, type, mask);
565 EXPORT_SYMBOL_GPL(crypto_alloc_ahash);
567 static int ahash_prepare_alg(struct ahash_alg *alg)
569 struct crypto_alg *base = &alg->halg.base;
571 if (alg->halg.digestsize > PAGE_SIZE / 8 ||
572 alg->halg.statesize > PAGE_SIZE / 8 ||
573 alg->halg.statesize == 0)
576 base->cra_type = &crypto_ahash_type;
577 base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
578 base->cra_flags |= CRYPTO_ALG_TYPE_AHASH;
583 int crypto_register_ahash(struct ahash_alg *alg)
585 struct crypto_alg *base = &alg->halg.base;
588 err = ahash_prepare_alg(alg);
592 return crypto_register_alg(base);
594 EXPORT_SYMBOL_GPL(crypto_register_ahash);
596 int crypto_unregister_ahash(struct ahash_alg *alg)
598 return crypto_unregister_alg(&alg->halg.base);
600 EXPORT_SYMBOL_GPL(crypto_unregister_ahash);
602 int ahash_register_instance(struct crypto_template *tmpl,
603 struct ahash_instance *inst)
607 err = ahash_prepare_alg(&inst->alg);
611 return crypto_register_instance(tmpl, ahash_crypto_instance(inst));
613 EXPORT_SYMBOL_GPL(ahash_register_instance);
615 void ahash_free_instance(struct crypto_instance *inst)
617 crypto_drop_spawn(crypto_instance_ctx(inst));
618 kfree(ahash_instance(inst));
620 EXPORT_SYMBOL_GPL(ahash_free_instance);
622 int crypto_init_ahash_spawn(struct crypto_ahash_spawn *spawn,
623 struct hash_alg_common *alg,
624 struct crypto_instance *inst)
626 return crypto_init_spawn2(&spawn->base, &alg->base, inst,
629 EXPORT_SYMBOL_GPL(crypto_init_ahash_spawn);
631 struct hash_alg_common *ahash_attr_alg(struct rtattr *rta, u32 type, u32 mask)
633 struct crypto_alg *alg;
635 alg = crypto_attr_alg2(rta, &crypto_ahash_type, type, mask);
636 return IS_ERR(alg) ? ERR_CAST(alg) : __crypto_hash_alg_common(alg);
638 EXPORT_SYMBOL_GPL(ahash_attr_alg);
640 MODULE_LICENSE("GPL");
641 MODULE_DESCRIPTION("Asynchronous cryptographic hash type");