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;
34 void *ubuf[] CRYPTO_MINALIGN_ATTR;
37 static inline struct ahash_alg *crypto_ahash_alg(struct crypto_ahash *hash)
39 return container_of(crypto_hash_alg_common(hash), struct ahash_alg,
43 static int hash_walk_next(struct crypto_hash_walk *walk)
45 unsigned int alignmask = walk->alignmask;
46 unsigned int offset = walk->offset;
47 unsigned int nbytes = min(walk->entrylen,
48 ((unsigned int)(PAGE_SIZE)) - offset);
50 if (walk->flags & CRYPTO_ALG_ASYNC)
51 walk->data = kmap(walk->pg);
53 walk->data = kmap_atomic(walk->pg);
56 if (offset & alignmask) {
57 unsigned int unaligned = alignmask + 1 - (offset & alignmask);
59 if (nbytes > unaligned)
63 walk->entrylen -= nbytes;
67 static int hash_walk_new_entry(struct crypto_hash_walk *walk)
69 struct scatterlist *sg;
72 walk->pg = sg_page(sg);
73 walk->offset = sg->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;
86 unsigned int nbytes = walk->entrylen;
88 walk->data -= walk->offset;
90 if (nbytes && walk->offset & alignmask && !err) {
91 walk->offset = ALIGN(walk->offset, alignmask + 1);
92 walk->data += walk->offset;
95 ((unsigned int)(PAGE_SIZE)) - walk->offset);
96 walk->entrylen -= nbytes;
101 if (walk->flags & CRYPTO_ALG_ASYNC)
104 kunmap_atomic(walk->data);
106 * The may sleep test only makes sense for sync users.
107 * Async users don't need to sleep here anyway.
109 crypto_yield(walk->flags);
118 return hash_walk_next(walk);
124 walk->sg = sg_next(walk->sg);
126 return hash_walk_new_entry(walk);
128 EXPORT_SYMBOL_GPL(crypto_hash_walk_done);
130 int crypto_hash_walk_first(struct ahash_request *req,
131 struct crypto_hash_walk *walk)
133 walk->total = req->nbytes;
140 walk->alignmask = crypto_ahash_alignmask(crypto_ahash_reqtfm(req));
142 walk->flags = req->base.flags & CRYPTO_TFM_REQ_MASK;
144 return hash_walk_new_entry(walk);
146 EXPORT_SYMBOL_GPL(crypto_hash_walk_first);
148 int crypto_ahash_walk_first(struct ahash_request *req,
149 struct crypto_hash_walk *walk)
151 walk->total = req->nbytes;
158 walk->alignmask = crypto_ahash_alignmask(crypto_ahash_reqtfm(req));
160 walk->flags = req->base.flags & CRYPTO_TFM_REQ_MASK;
161 walk->flags |= CRYPTO_ALG_ASYNC;
163 BUILD_BUG_ON(CRYPTO_TFM_REQ_MASK & CRYPTO_ALG_ASYNC);
165 return hash_walk_new_entry(walk);
167 EXPORT_SYMBOL_GPL(crypto_ahash_walk_first);
169 int crypto_hash_walk_first_compat(struct hash_desc *hdesc,
170 struct crypto_hash_walk *walk,
171 struct scatterlist *sg, unsigned int len)
180 walk->alignmask = crypto_hash_alignmask(hdesc->tfm);
182 walk->flags = hdesc->flags & CRYPTO_TFM_REQ_MASK;
184 return hash_walk_new_entry(walk);
187 static int ahash_setkey_unaligned(struct crypto_ahash *tfm, const u8 *key,
190 unsigned long alignmask = crypto_ahash_alignmask(tfm);
192 u8 *buffer, *alignbuffer;
193 unsigned long absize;
195 absize = keylen + alignmask;
196 buffer = kmalloc(absize, GFP_KERNEL);
200 alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
201 memcpy(alignbuffer, key, keylen);
202 ret = tfm->setkey(tfm, alignbuffer, keylen);
207 int crypto_ahash_setkey(struct crypto_ahash *tfm, const u8 *key,
210 unsigned long alignmask = crypto_ahash_alignmask(tfm);
212 if ((unsigned long)key & alignmask)
213 return ahash_setkey_unaligned(tfm, key, keylen);
215 return tfm->setkey(tfm, key, keylen);
217 EXPORT_SYMBOL_GPL(crypto_ahash_setkey);
219 static int ahash_nosetkey(struct crypto_ahash *tfm, const u8 *key,
225 static inline unsigned int ahash_align_buffer_size(unsigned len,
228 return len + (mask & ~(crypto_tfm_ctx_alignment() - 1));
231 static int ahash_save_req(struct ahash_request *req, crypto_completion_t cplt)
233 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
234 unsigned long alignmask = crypto_ahash_alignmask(tfm);
235 unsigned int ds = crypto_ahash_digestsize(tfm);
236 struct ahash_request_priv *priv;
238 priv = kmalloc(sizeof(*priv) + ahash_align_buffer_size(ds, alignmask),
239 (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ?
240 GFP_KERNEL : GFP_ATOMIC);
245 * WARNING: Voodoo programming below!
247 * The code below is obscure and hard to understand, thus explanation
248 * is necessary. See include/crypto/hash.h and include/linux/crypto.h
249 * to understand the layout of structures used here!
251 * The code here will replace portions of the ORIGINAL request with
252 * pointers to new code and buffers so the hashing operation can store
253 * the result in aligned buffer. We will call the modified request
254 * an ADJUSTED request.
256 * The newly mangled request will look as such:
259 * .result = ADJUSTED[new aligned buffer]
260 * .base.complete = ADJUSTED[pointer to completion function]
261 * .base.data = ADJUSTED[*req (pointer to self)]
262 * .priv = ADJUSTED[new priv] {
263 * .result = ORIGINAL(result)
264 * .complete = ORIGINAL(base.complete)
265 * .data = ORIGINAL(base.data)
269 priv->result = req->result;
270 priv->complete = req->base.complete;
271 priv->data = req->base.data;
273 * WARNING: We do not backup req->priv here! The req->priv
274 * is for internal use of the Crypto API and the
275 * user must _NOT_ _EVER_ depend on it's content!
278 req->result = PTR_ALIGN((u8 *)priv->ubuf, alignmask + 1);
279 req->base.complete = cplt;
280 req->base.data = req;
286 static void ahash_restore_req(struct ahash_request *req)
288 struct ahash_request_priv *priv = req->priv;
290 /* Restore the original crypto request. */
291 req->result = priv->result;
292 req->base.complete = priv->complete;
293 req->base.data = priv->data;
296 /* Free the req->priv.priv from the ADJUSTED request. */
300 static void ahash_op_unaligned_finish(struct ahash_request *req, int err)
302 struct ahash_request_priv *priv = req->priv;
304 if (err == -EINPROGRESS)
308 memcpy(priv->result, req->result,
309 crypto_ahash_digestsize(crypto_ahash_reqtfm(req)));
311 ahash_restore_req(req);
314 static void ahash_op_unaligned_done(struct crypto_async_request *req, int err)
316 struct ahash_request *areq = req->data;
319 * Restore the original request, see ahash_op_unaligned() for what
322 * The "struct ahash_request *req" here is in fact the "req.base"
323 * from the ADJUSTED request from ahash_op_unaligned(), thus as it
324 * is a pointer to self, it is also the ADJUSTED "req" .
327 /* First copy req->result into req->priv.result */
328 ahash_op_unaligned_finish(areq, err);
330 /* Complete the ORIGINAL request. */
331 areq->base.complete(&areq->base, err);
334 static int ahash_op_unaligned(struct ahash_request *req,
335 int (*op)(struct ahash_request *))
339 err = ahash_save_req(req, ahash_op_unaligned_done);
344 ahash_op_unaligned_finish(req, err);
349 static int crypto_ahash_op(struct ahash_request *req,
350 int (*op)(struct ahash_request *))
352 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
353 unsigned long alignmask = crypto_ahash_alignmask(tfm);
355 if ((unsigned long)req->result & alignmask)
356 return ahash_op_unaligned(req, op);
361 int crypto_ahash_final(struct ahash_request *req)
363 return crypto_ahash_op(req, crypto_ahash_reqtfm(req)->final);
365 EXPORT_SYMBOL_GPL(crypto_ahash_final);
367 int crypto_ahash_finup(struct ahash_request *req)
369 return crypto_ahash_op(req, crypto_ahash_reqtfm(req)->finup);
371 EXPORT_SYMBOL_GPL(crypto_ahash_finup);
373 int crypto_ahash_digest(struct ahash_request *req)
375 return crypto_ahash_op(req, crypto_ahash_reqtfm(req)->digest);
377 EXPORT_SYMBOL_GPL(crypto_ahash_digest);
379 static void ahash_def_finup_finish2(struct ahash_request *req, int err)
381 struct ahash_request_priv *priv = req->priv;
383 if (err == -EINPROGRESS)
387 memcpy(priv->result, req->result,
388 crypto_ahash_digestsize(crypto_ahash_reqtfm(req)));
390 ahash_restore_req(req);
393 static void ahash_def_finup_done2(struct crypto_async_request *req, int err)
395 struct ahash_request *areq = req->data;
397 ahash_def_finup_finish2(areq, err);
399 areq->base.complete(&areq->base, err);
402 static int ahash_def_finup_finish1(struct ahash_request *req, int err)
407 req->base.complete = ahash_def_finup_done2;
408 req->base.flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
409 err = crypto_ahash_reqtfm(req)->final(req);
412 ahash_def_finup_finish2(req, err);
416 static void ahash_def_finup_done1(struct crypto_async_request *req, int err)
418 struct ahash_request *areq = req->data;
420 err = ahash_def_finup_finish1(areq, err);
422 areq->base.complete(&areq->base, err);
425 static int ahash_def_finup(struct ahash_request *req)
427 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
430 err = ahash_save_req(req, ahash_def_finup_done1);
434 err = tfm->update(req);
435 return ahash_def_finup_finish1(req, err);
438 static int ahash_no_export(struct ahash_request *req, void *out)
443 static int ahash_no_import(struct ahash_request *req, const void *in)
448 static int crypto_ahash_init_tfm(struct crypto_tfm *tfm)
450 struct crypto_ahash *hash = __crypto_ahash_cast(tfm);
451 struct ahash_alg *alg = crypto_ahash_alg(hash);
453 hash->setkey = ahash_nosetkey;
454 hash->has_setkey = false;
455 hash->export = ahash_no_export;
456 hash->import = ahash_no_import;
458 if (tfm->__crt_alg->cra_type != &crypto_ahash_type)
459 return crypto_init_shash_ops_async(tfm);
461 hash->init = alg->init;
462 hash->update = alg->update;
463 hash->final = alg->final;
464 hash->finup = alg->finup ?: ahash_def_finup;
465 hash->digest = alg->digest;
468 hash->setkey = alg->setkey;
469 hash->has_setkey = true;
472 hash->export = alg->export;
474 hash->import = alg->import;
479 static unsigned int crypto_ahash_extsize(struct crypto_alg *alg)
481 if (alg->cra_type == &crypto_ahash_type)
482 return alg->cra_ctxsize;
484 return sizeof(struct crypto_shash *);
488 static int crypto_ahash_report(struct sk_buff *skb, struct crypto_alg *alg)
490 struct crypto_report_hash rhash;
492 strncpy(rhash.type, "ahash", sizeof(rhash.type));
494 rhash.blocksize = alg->cra_blocksize;
495 rhash.digestsize = __crypto_hash_alg_common(alg)->digestsize;
497 if (nla_put(skb, CRYPTOCFGA_REPORT_HASH,
498 sizeof(struct crypto_report_hash), &rhash))
499 goto nla_put_failure;
506 static int crypto_ahash_report(struct sk_buff *skb, struct crypto_alg *alg)
512 static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg)
513 __attribute__ ((unused));
514 static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg)
516 seq_printf(m, "type : ahash\n");
517 seq_printf(m, "async : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
519 seq_printf(m, "blocksize : %u\n", alg->cra_blocksize);
520 seq_printf(m, "digestsize : %u\n",
521 __crypto_hash_alg_common(alg)->digestsize);
524 const struct crypto_type crypto_ahash_type = {
525 .extsize = crypto_ahash_extsize,
526 .init_tfm = crypto_ahash_init_tfm,
527 #ifdef CONFIG_PROC_FS
528 .show = crypto_ahash_show,
530 .report = crypto_ahash_report,
531 .maskclear = ~CRYPTO_ALG_TYPE_MASK,
532 .maskset = CRYPTO_ALG_TYPE_AHASH_MASK,
533 .type = CRYPTO_ALG_TYPE_AHASH,
534 .tfmsize = offsetof(struct crypto_ahash, base),
536 EXPORT_SYMBOL_GPL(crypto_ahash_type);
538 struct crypto_ahash *crypto_alloc_ahash(const char *alg_name, u32 type,
541 return crypto_alloc_tfm(alg_name, &crypto_ahash_type, type, mask);
543 EXPORT_SYMBOL_GPL(crypto_alloc_ahash);
545 static int ahash_prepare_alg(struct ahash_alg *alg)
547 struct crypto_alg *base = &alg->halg.base;
549 if (alg->halg.digestsize > PAGE_SIZE / 8 ||
550 alg->halg.statesize > PAGE_SIZE / 8 ||
551 alg->halg.statesize == 0)
554 base->cra_type = &crypto_ahash_type;
555 base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
556 base->cra_flags |= CRYPTO_ALG_TYPE_AHASH;
561 int crypto_register_ahash(struct ahash_alg *alg)
563 struct crypto_alg *base = &alg->halg.base;
566 err = ahash_prepare_alg(alg);
570 return crypto_register_alg(base);
572 EXPORT_SYMBOL_GPL(crypto_register_ahash);
574 int crypto_unregister_ahash(struct ahash_alg *alg)
576 return crypto_unregister_alg(&alg->halg.base);
578 EXPORT_SYMBOL_GPL(crypto_unregister_ahash);
580 int ahash_register_instance(struct crypto_template *tmpl,
581 struct ahash_instance *inst)
585 err = ahash_prepare_alg(&inst->alg);
589 return crypto_register_instance(tmpl, ahash_crypto_instance(inst));
591 EXPORT_SYMBOL_GPL(ahash_register_instance);
593 void ahash_free_instance(struct crypto_instance *inst)
595 crypto_drop_spawn(crypto_instance_ctx(inst));
596 kfree(ahash_instance(inst));
598 EXPORT_SYMBOL_GPL(ahash_free_instance);
600 int crypto_init_ahash_spawn(struct crypto_ahash_spawn *spawn,
601 struct hash_alg_common *alg,
602 struct crypto_instance *inst)
604 return crypto_init_spawn2(&spawn->base, &alg->base, inst,
607 EXPORT_SYMBOL_GPL(crypto_init_ahash_spawn);
609 struct hash_alg_common *ahash_attr_alg(struct rtattr *rta, u32 type, u32 mask)
611 struct crypto_alg *alg;
613 alg = crypto_attr_alg2(rta, &crypto_ahash_type, type, mask);
614 return IS_ERR(alg) ? ERR_CAST(alg) : __crypto_hash_alg_common(alg);
616 EXPORT_SYMBOL_GPL(ahash_attr_alg);
618 MODULE_LICENSE("GPL");
619 MODULE_DESCRIPTION("Asynchronous cryptographic hash type");