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->offset = sg->offset;
73 walk->pg = sg_page(walk->sg) + (walk->offset >> PAGE_SHIFT);
74 walk->offset = offset_in_page(walk->offset);
75 walk->entrylen = sg->length;
77 if (walk->entrylen > walk->total)
78 walk->entrylen = walk->total;
79 walk->total -= walk->entrylen;
81 return hash_walk_next(walk);
84 int crypto_hash_walk_done(struct crypto_hash_walk *walk, int err)
86 unsigned int alignmask = walk->alignmask;
87 unsigned int nbytes = walk->entrylen;
89 walk->data -= walk->offset;
91 if (nbytes && walk->offset & alignmask && !err) {
92 walk->offset = ALIGN(walk->offset, alignmask + 1);
93 walk->data += walk->offset;
96 ((unsigned int)(PAGE_SIZE)) - walk->offset);
97 walk->entrylen -= nbytes;
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);
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 int crypto_hash_walk_first_compat(struct hash_desc *hdesc,
171 struct crypto_hash_walk *walk,
172 struct scatterlist *sg, unsigned int len)
181 walk->alignmask = crypto_hash_alignmask(hdesc->tfm);
183 walk->flags = hdesc->flags & CRYPTO_TFM_REQ_MASK;
185 return hash_walk_new_entry(walk);
188 static int ahash_setkey_unaligned(struct crypto_ahash *tfm, const u8 *key,
191 unsigned long alignmask = crypto_ahash_alignmask(tfm);
193 u8 *buffer, *alignbuffer;
194 unsigned long absize;
196 absize = keylen + alignmask;
197 buffer = kmalloc(absize, GFP_KERNEL);
201 alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
202 memcpy(alignbuffer, key, keylen);
203 ret = tfm->setkey(tfm, alignbuffer, keylen);
208 int crypto_ahash_setkey(struct crypto_ahash *tfm, const u8 *key,
211 unsigned long alignmask = crypto_ahash_alignmask(tfm);
213 if ((unsigned long)key & alignmask)
214 return ahash_setkey_unaligned(tfm, key, keylen);
216 return tfm->setkey(tfm, key, keylen);
218 EXPORT_SYMBOL_GPL(crypto_ahash_setkey);
220 static int ahash_nosetkey(struct crypto_ahash *tfm, const u8 *key,
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;
274 * WARNING: We do not backup req->priv here! The req->priv
275 * is for internal use of the Crypto API and the
276 * user must _NOT_ _EVER_ depend on it's content!
279 req->result = PTR_ALIGN((u8 *)priv->ubuf, alignmask + 1);
280 req->base.complete = cplt;
281 req->base.data = req;
287 static void ahash_restore_req(struct ahash_request *req)
289 struct ahash_request_priv *priv = req->priv;
291 /* Restore the original crypto request. */
292 req->result = priv->result;
293 req->base.complete = priv->complete;
294 req->base.data = priv->data;
297 /* Free the req->priv.priv from the ADJUSTED request. */
301 static void ahash_op_unaligned_finish(struct ahash_request *req, int err)
303 struct ahash_request_priv *priv = req->priv;
305 if (err == -EINPROGRESS)
309 memcpy(priv->result, req->result,
310 crypto_ahash_digestsize(crypto_ahash_reqtfm(req)));
312 ahash_restore_req(req);
315 static void ahash_op_unaligned_done(struct crypto_async_request *req, int err)
317 struct ahash_request *areq = req->data;
320 * Restore the original request, see ahash_op_unaligned() for what
323 * The "struct ahash_request *req" here is in fact the "req.base"
324 * from the ADJUSTED request from ahash_op_unaligned(), thus as it
325 * is a pointer to self, it is also the ADJUSTED "req" .
328 /* First copy req->result into req->priv.result */
329 ahash_op_unaligned_finish(areq, err);
331 /* Complete the ORIGINAL request. */
332 areq->base.complete(&areq->base, err);
335 static int ahash_op_unaligned(struct ahash_request *req,
336 int (*op)(struct ahash_request *))
340 err = ahash_save_req(req, ahash_op_unaligned_done);
345 ahash_op_unaligned_finish(req, err);
350 static int crypto_ahash_op(struct ahash_request *req,
351 int (*op)(struct ahash_request *))
353 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
354 unsigned long alignmask = crypto_ahash_alignmask(tfm);
356 if ((unsigned long)req->result & alignmask)
357 return ahash_op_unaligned(req, op);
362 int crypto_ahash_final(struct ahash_request *req)
364 return crypto_ahash_op(req, crypto_ahash_reqtfm(req)->final);
366 EXPORT_SYMBOL_GPL(crypto_ahash_final);
368 int crypto_ahash_finup(struct ahash_request *req)
370 return crypto_ahash_op(req, crypto_ahash_reqtfm(req)->finup);
372 EXPORT_SYMBOL_GPL(crypto_ahash_finup);
374 int crypto_ahash_digest(struct ahash_request *req)
376 return crypto_ahash_op(req, crypto_ahash_reqtfm(req)->digest);
378 EXPORT_SYMBOL_GPL(crypto_ahash_digest);
380 static void ahash_def_finup_finish2(struct ahash_request *req, int err)
382 struct ahash_request_priv *priv = req->priv;
384 if (err == -EINPROGRESS)
388 memcpy(priv->result, req->result,
389 crypto_ahash_digestsize(crypto_ahash_reqtfm(req)));
391 ahash_restore_req(req);
394 static void ahash_def_finup_done2(struct crypto_async_request *req, int err)
396 struct ahash_request *areq = req->data;
398 ahash_def_finup_finish2(areq, err);
400 areq->base.complete(&areq->base, err);
403 static int ahash_def_finup_finish1(struct ahash_request *req, int err)
408 req->base.complete = ahash_def_finup_done2;
409 req->base.flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
410 err = crypto_ahash_reqtfm(req)->final(req);
413 ahash_def_finup_finish2(req, err);
417 static void ahash_def_finup_done1(struct crypto_async_request *req, int err)
419 struct ahash_request *areq = req->data;
421 err = ahash_def_finup_finish1(areq, err);
423 areq->base.complete(&areq->base, err);
426 static int ahash_def_finup(struct ahash_request *req)
428 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
431 err = ahash_save_req(req, ahash_def_finup_done1);
435 err = tfm->update(req);
436 return ahash_def_finup_finish1(req, err);
439 static int ahash_no_export(struct ahash_request *req, void *out)
444 static int ahash_no_import(struct ahash_request *req, const void *in)
449 static int crypto_ahash_init_tfm(struct crypto_tfm *tfm)
451 struct crypto_ahash *hash = __crypto_ahash_cast(tfm);
452 struct ahash_alg *alg = crypto_ahash_alg(hash);
454 hash->setkey = ahash_nosetkey;
455 hash->has_setkey = false;
456 hash->export = ahash_no_export;
457 hash->import = ahash_no_import;
459 if (tfm->__crt_alg->cra_type != &crypto_ahash_type)
460 return crypto_init_shash_ops_async(tfm);
462 hash->init = alg->init;
463 hash->update = alg->update;
464 hash->final = alg->final;
465 hash->finup = alg->finup ?: ahash_def_finup;
466 hash->digest = alg->digest;
469 hash->setkey = alg->setkey;
470 hash->has_setkey = true;
473 hash->export = alg->export;
475 hash->import = alg->import;
480 static unsigned int crypto_ahash_extsize(struct crypto_alg *alg)
482 if (alg->cra_type == &crypto_ahash_type)
483 return alg->cra_ctxsize;
485 return sizeof(struct crypto_shash *);
489 static int crypto_ahash_report(struct sk_buff *skb, struct crypto_alg *alg)
491 struct crypto_report_hash rhash;
493 strncpy(rhash.type, "ahash", sizeof(rhash.type));
495 rhash.blocksize = alg->cra_blocksize;
496 rhash.digestsize = __crypto_hash_alg_common(alg)->digestsize;
498 if (nla_put(skb, CRYPTOCFGA_REPORT_HASH,
499 sizeof(struct crypto_report_hash), &rhash))
500 goto nla_put_failure;
507 static int crypto_ahash_report(struct sk_buff *skb, struct crypto_alg *alg)
513 static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg)
514 __attribute__ ((unused));
515 static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg)
517 seq_printf(m, "type : ahash\n");
518 seq_printf(m, "async : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
520 seq_printf(m, "blocksize : %u\n", alg->cra_blocksize);
521 seq_printf(m, "digestsize : %u\n",
522 __crypto_hash_alg_common(alg)->digestsize);
525 const struct crypto_type crypto_ahash_type = {
526 .extsize = crypto_ahash_extsize,
527 .init_tfm = crypto_ahash_init_tfm,
528 #ifdef CONFIG_PROC_FS
529 .show = crypto_ahash_show,
531 .report = crypto_ahash_report,
532 .maskclear = ~CRYPTO_ALG_TYPE_MASK,
533 .maskset = CRYPTO_ALG_TYPE_AHASH_MASK,
534 .type = CRYPTO_ALG_TYPE_AHASH,
535 .tfmsize = offsetof(struct crypto_ahash, base),
537 EXPORT_SYMBOL_GPL(crypto_ahash_type);
539 struct crypto_ahash *crypto_alloc_ahash(const char *alg_name, u32 type,
542 return crypto_alloc_tfm(alg_name, &crypto_ahash_type, type, mask);
544 EXPORT_SYMBOL_GPL(crypto_alloc_ahash);
546 static int ahash_prepare_alg(struct ahash_alg *alg)
548 struct crypto_alg *base = &alg->halg.base;
550 if (alg->halg.digestsize > PAGE_SIZE / 8 ||
551 alg->halg.statesize > PAGE_SIZE / 8 ||
552 alg->halg.statesize == 0)
555 base->cra_type = &crypto_ahash_type;
556 base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
557 base->cra_flags |= CRYPTO_ALG_TYPE_AHASH;
562 int crypto_register_ahash(struct ahash_alg *alg)
564 struct crypto_alg *base = &alg->halg.base;
567 err = ahash_prepare_alg(alg);
571 return crypto_register_alg(base);
573 EXPORT_SYMBOL_GPL(crypto_register_ahash);
575 int crypto_unregister_ahash(struct ahash_alg *alg)
577 return crypto_unregister_alg(&alg->halg.base);
579 EXPORT_SYMBOL_GPL(crypto_unregister_ahash);
581 int ahash_register_instance(struct crypto_template *tmpl,
582 struct ahash_instance *inst)
586 err = ahash_prepare_alg(&inst->alg);
590 return crypto_register_instance(tmpl, ahash_crypto_instance(inst));
592 EXPORT_SYMBOL_GPL(ahash_register_instance);
594 void ahash_free_instance(struct crypto_instance *inst)
596 crypto_drop_spawn(crypto_instance_ctx(inst));
597 kfree(ahash_instance(inst));
599 EXPORT_SYMBOL_GPL(ahash_free_instance);
601 int crypto_init_ahash_spawn(struct crypto_ahash_spawn *spawn,
602 struct hash_alg_common *alg,
603 struct crypto_instance *inst)
605 return crypto_init_spawn2(&spawn->base, &alg->base, inst,
608 EXPORT_SYMBOL_GPL(crypto_init_ahash_spawn);
610 struct hash_alg_common *ahash_attr_alg(struct rtattr *rta, u32 type, u32 mask)
612 struct crypto_alg *alg;
614 alg = crypto_attr_alg2(rta, &crypto_ahash_type, type, mask);
615 return IS_ERR(alg) ? ERR_CAST(alg) : __crypto_hash_alg_common(alg);
617 EXPORT_SYMBOL_GPL(ahash_attr_alg);
619 MODULE_LICENSE("GPL");
620 MODULE_DESCRIPTION("Asynchronous cryptographic hash type");