Root/crypto/ahash.c

1/*
2 * Asynchronous Cryptographic Hash operations.
3 *
4 * This is the asynchronous version of hash.c with notification of
5 * completion via a callback.
6 *
7 * Copyright (c) 2008 Loc Ho <lho@amcc.com>
8 *
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)
12 * any later version.
13 *
14 */
15
16#include <crypto/internal/hash.h>
17#include <crypto/scatterwalk.h>
18#include <linux/err.h>
19#include <linux/kernel.h>
20#include <linux/module.h>
21#include <linux/sched.h>
22#include <linux/slab.h>
23#include <linux/seq_file.h>
24
25#include "internal.h"
26
27struct ahash_request_priv {
28    crypto_completion_t complete;
29    void *data;
30    u8 *result;
31    void *ubuf[] CRYPTO_MINALIGN_ATTR;
32};
33
34static inline struct ahash_alg *crypto_ahash_alg(struct crypto_ahash *hash)
35{
36    return container_of(crypto_hash_alg_common(hash), struct ahash_alg,
37                halg);
38}
39
40static int hash_walk_next(struct crypto_hash_walk *walk)
41{
42    unsigned int alignmask = walk->alignmask;
43    unsigned int offset = walk->offset;
44    unsigned int nbytes = min(walk->entrylen,
45                  ((unsigned int)(PAGE_SIZE)) - offset);
46
47    walk->data = crypto_kmap(walk->pg, 0);
48    walk->data += offset;
49
50    if (offset & alignmask) {
51        unsigned int unaligned = alignmask + 1 - (offset & alignmask);
52        if (nbytes > unaligned)
53            nbytes = unaligned;
54    }
55
56    walk->entrylen -= nbytes;
57    return nbytes;
58}
59
60static int hash_walk_new_entry(struct crypto_hash_walk *walk)
61{
62    struct scatterlist *sg;
63
64    sg = walk->sg;
65    walk->pg = sg_page(sg);
66    walk->offset = sg->offset;
67    walk->entrylen = sg->length;
68
69    if (walk->entrylen > walk->total)
70        walk->entrylen = walk->total;
71    walk->total -= walk->entrylen;
72
73    return hash_walk_next(walk);
74}
75
76int crypto_hash_walk_done(struct crypto_hash_walk *walk, int err)
77{
78    unsigned int alignmask = walk->alignmask;
79    unsigned int nbytes = walk->entrylen;
80
81    walk->data -= walk->offset;
82
83    if (nbytes && walk->offset & alignmask && !err) {
84        walk->offset = ALIGN(walk->offset, alignmask + 1);
85        walk->data += walk->offset;
86
87        nbytes = min(nbytes,
88                 ((unsigned int)(PAGE_SIZE)) - walk->offset);
89        walk->entrylen -= nbytes;
90
91        return nbytes;
92    }
93
94    crypto_kunmap(walk->data, 0);
95    crypto_yield(walk->flags);
96
97    if (err)
98        return err;
99
100    if (nbytes) {
101        walk->offset = 0;
102        walk->pg++;
103        return hash_walk_next(walk);
104    }
105
106    if (!walk->total)
107        return 0;
108
109    walk->sg = scatterwalk_sg_next(walk->sg);
110
111    return hash_walk_new_entry(walk);
112}
113EXPORT_SYMBOL_GPL(crypto_hash_walk_done);
114
115int crypto_hash_walk_first(struct ahash_request *req,
116               struct crypto_hash_walk *walk)
117{
118    walk->total = req->nbytes;
119
120    if (!walk->total)
121        return 0;
122
123    walk->alignmask = crypto_ahash_alignmask(crypto_ahash_reqtfm(req));
124    walk->sg = req->src;
125    walk->flags = req->base.flags;
126
127    return hash_walk_new_entry(walk);
128}
129EXPORT_SYMBOL_GPL(crypto_hash_walk_first);
130
131int crypto_hash_walk_first_compat(struct hash_desc *hdesc,
132                  struct crypto_hash_walk *walk,
133                  struct scatterlist *sg, unsigned int len)
134{
135    walk->total = len;
136
137    if (!walk->total)
138        return 0;
139
140    walk->alignmask = crypto_hash_alignmask(hdesc->tfm);
141    walk->sg = sg;
142    walk->flags = hdesc->flags;
143
144    return hash_walk_new_entry(walk);
145}
146
147static int ahash_setkey_unaligned(struct crypto_ahash *tfm, const u8 *key,
148                unsigned int keylen)
149{
150    unsigned long alignmask = crypto_ahash_alignmask(tfm);
151    int ret;
152    u8 *buffer, *alignbuffer;
153    unsigned long absize;
154
155    absize = keylen + alignmask;
156    buffer = kmalloc(absize, GFP_KERNEL);
157    if (!buffer)
158        return -ENOMEM;
159
160    alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
161    memcpy(alignbuffer, key, keylen);
162    ret = tfm->setkey(tfm, alignbuffer, keylen);
163    kzfree(buffer);
164    return ret;
165}
166
167int crypto_ahash_setkey(struct crypto_ahash *tfm, const u8 *key,
168            unsigned int keylen)
169{
170    unsigned long alignmask = crypto_ahash_alignmask(tfm);
171
172    if ((unsigned long)key & alignmask)
173        return ahash_setkey_unaligned(tfm, key, keylen);
174
175    return tfm->setkey(tfm, key, keylen);
176}
177EXPORT_SYMBOL_GPL(crypto_ahash_setkey);
178
179static int ahash_nosetkey(struct crypto_ahash *tfm, const u8 *key,
180              unsigned int keylen)
181{
182    return -ENOSYS;
183}
184
185static inline unsigned int ahash_align_buffer_size(unsigned len,
186                           unsigned long mask)
187{
188    return len + (mask & ~(crypto_tfm_ctx_alignment() - 1));
189}
190
191static void ahash_op_unaligned_finish(struct ahash_request *req, int err)
192{
193    struct ahash_request_priv *priv = req->priv;
194
195    if (err == -EINPROGRESS)
196        return;
197
198    if (!err)
199        memcpy(priv->result, req->result,
200               crypto_ahash_digestsize(crypto_ahash_reqtfm(req)));
201
202    kzfree(priv);
203}
204
205static void ahash_op_unaligned_done(struct crypto_async_request *req, int err)
206{
207    struct ahash_request *areq = req->data;
208    struct ahash_request_priv *priv = areq->priv;
209    crypto_completion_t complete = priv->complete;
210    void *data = priv->data;
211
212    ahash_op_unaligned_finish(areq, err);
213
214    complete(data, err);
215}
216
217static int ahash_op_unaligned(struct ahash_request *req,
218                  int (*op)(struct ahash_request *))
219{
220    struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
221    unsigned long alignmask = crypto_ahash_alignmask(tfm);
222    unsigned int ds = crypto_ahash_digestsize(tfm);
223    struct ahash_request_priv *priv;
224    int err;
225
226    priv = kmalloc(sizeof(*priv) + ahash_align_buffer_size(ds, alignmask),
227               (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ?
228               GFP_KERNEL : GFP_ATOMIC);
229    if (!priv)
230        return -ENOMEM;
231
232    priv->result = req->result;
233    priv->complete = req->base.complete;
234    priv->data = req->base.data;
235
236    req->result = PTR_ALIGN((u8 *)priv->ubuf, alignmask + 1);
237    req->base.complete = ahash_op_unaligned_done;
238    req->base.data = req;
239    req->priv = priv;
240
241    err = op(req);
242    ahash_op_unaligned_finish(req, err);
243
244    return err;
245}
246
247static int crypto_ahash_op(struct ahash_request *req,
248               int (*op)(struct ahash_request *))
249{
250    struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
251    unsigned long alignmask = crypto_ahash_alignmask(tfm);
252
253    if ((unsigned long)req->result & alignmask)
254        return ahash_op_unaligned(req, op);
255
256    return op(req);
257}
258
259int crypto_ahash_final(struct ahash_request *req)
260{
261    return crypto_ahash_op(req, crypto_ahash_reqtfm(req)->final);
262}
263EXPORT_SYMBOL_GPL(crypto_ahash_final);
264
265int crypto_ahash_finup(struct ahash_request *req)
266{
267    return crypto_ahash_op(req, crypto_ahash_reqtfm(req)->finup);
268}
269EXPORT_SYMBOL_GPL(crypto_ahash_finup);
270
271int crypto_ahash_digest(struct ahash_request *req)
272{
273    return crypto_ahash_op(req, crypto_ahash_reqtfm(req)->digest);
274}
275EXPORT_SYMBOL_GPL(crypto_ahash_digest);
276
277static void ahash_def_finup_finish2(struct ahash_request *req, int err)
278{
279    struct ahash_request_priv *priv = req->priv;
280
281    if (err == -EINPROGRESS)
282        return;
283
284    if (!err)
285        memcpy(priv->result, req->result,
286               crypto_ahash_digestsize(crypto_ahash_reqtfm(req)));
287
288    kzfree(priv);
289}
290
291static void ahash_def_finup_done2(struct crypto_async_request *req, int err)
292{
293    struct ahash_request *areq = req->data;
294    struct ahash_request_priv *priv = areq->priv;
295    crypto_completion_t complete = priv->complete;
296    void *data = priv->data;
297
298    ahash_def_finup_finish2(areq, err);
299
300    complete(data, err);
301}
302
303static int ahash_def_finup_finish1(struct ahash_request *req, int err)
304{
305    if (err)
306        goto out;
307
308    req->base.complete = ahash_def_finup_done2;
309    req->base.flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
310    err = crypto_ahash_reqtfm(req)->final(req);
311
312out:
313    ahash_def_finup_finish2(req, err);
314    return err;
315}
316
317static void ahash_def_finup_done1(struct crypto_async_request *req, int err)
318{
319    struct ahash_request *areq = req->data;
320    struct ahash_request_priv *priv = areq->priv;
321    crypto_completion_t complete = priv->complete;
322    void *data = priv->data;
323
324    err = ahash_def_finup_finish1(areq, err);
325
326    complete(data, err);
327}
328
329static int ahash_def_finup(struct ahash_request *req)
330{
331    struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
332    unsigned long alignmask = crypto_ahash_alignmask(tfm);
333    unsigned int ds = crypto_ahash_digestsize(tfm);
334    struct ahash_request_priv *priv;
335
336    priv = kmalloc(sizeof(*priv) + ahash_align_buffer_size(ds, alignmask),
337               (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ?
338               GFP_KERNEL : GFP_ATOMIC);
339    if (!priv)
340        return -ENOMEM;
341
342    priv->result = req->result;
343    priv->complete = req->base.complete;
344    priv->data = req->base.data;
345
346    req->result = PTR_ALIGN((u8 *)priv->ubuf, alignmask + 1);
347    req->base.complete = ahash_def_finup_done1;
348    req->base.data = req;
349    req->priv = priv;
350
351    return ahash_def_finup_finish1(req, tfm->update(req));
352}
353
354static int ahash_no_export(struct ahash_request *req, void *out)
355{
356    return -ENOSYS;
357}
358
359static int ahash_no_import(struct ahash_request *req, const void *in)
360{
361    return -ENOSYS;
362}
363
364static int crypto_ahash_init_tfm(struct crypto_tfm *tfm)
365{
366    struct crypto_ahash *hash = __crypto_ahash_cast(tfm);
367    struct ahash_alg *alg = crypto_ahash_alg(hash);
368
369    hash->setkey = ahash_nosetkey;
370    hash->export = ahash_no_export;
371    hash->import = ahash_no_import;
372
373    if (tfm->__crt_alg->cra_type != &crypto_ahash_type)
374        return crypto_init_shash_ops_async(tfm);
375
376    hash->init = alg->init;
377    hash->update = alg->update;
378    hash->final = alg->final;
379    hash->finup = alg->finup ?: ahash_def_finup;
380    hash->digest = alg->digest;
381
382    if (alg->setkey)
383        hash->setkey = alg->setkey;
384    if (alg->export)
385        hash->export = alg->export;
386    if (alg->import)
387        hash->import = alg->import;
388
389    return 0;
390}
391
392static unsigned int crypto_ahash_extsize(struct crypto_alg *alg)
393{
394    if (alg->cra_type == &crypto_ahash_type)
395        return alg->cra_ctxsize;
396
397    return sizeof(struct crypto_shash *);
398}
399
400static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg)
401    __attribute__ ((unused));
402static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg)
403{
404    seq_printf(m, "type : ahash\n");
405    seq_printf(m, "async : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
406                         "yes" : "no");
407    seq_printf(m, "blocksize : %u\n", alg->cra_blocksize);
408    seq_printf(m, "digestsize : %u\n",
409           __crypto_hash_alg_common(alg)->digestsize);
410}
411
412const struct crypto_type crypto_ahash_type = {
413    .extsize = crypto_ahash_extsize,
414    .init_tfm = crypto_ahash_init_tfm,
415#ifdef CONFIG_PROC_FS
416    .show = crypto_ahash_show,
417#endif
418    .maskclear = ~CRYPTO_ALG_TYPE_MASK,
419    .maskset = CRYPTO_ALG_TYPE_AHASH_MASK,
420    .type = CRYPTO_ALG_TYPE_AHASH,
421    .tfmsize = offsetof(struct crypto_ahash, base),
422};
423EXPORT_SYMBOL_GPL(crypto_ahash_type);
424
425struct crypto_ahash *crypto_alloc_ahash(const char *alg_name, u32 type,
426                    u32 mask)
427{
428    return crypto_alloc_tfm(alg_name, &crypto_ahash_type, type, mask);
429}
430EXPORT_SYMBOL_GPL(crypto_alloc_ahash);
431
432static int ahash_prepare_alg(struct ahash_alg *alg)
433{
434    struct crypto_alg *base = &alg->halg.base;
435
436    if (alg->halg.digestsize > PAGE_SIZE / 8 ||
437        alg->halg.statesize > PAGE_SIZE / 8)
438        return -EINVAL;
439
440    base->cra_type = &crypto_ahash_type;
441    base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
442    base->cra_flags |= CRYPTO_ALG_TYPE_AHASH;
443
444    return 0;
445}
446
447int crypto_register_ahash(struct ahash_alg *alg)
448{
449    struct crypto_alg *base = &alg->halg.base;
450    int err;
451
452    err = ahash_prepare_alg(alg);
453    if (err)
454        return err;
455
456    return crypto_register_alg(base);
457}
458EXPORT_SYMBOL_GPL(crypto_register_ahash);
459
460int crypto_unregister_ahash(struct ahash_alg *alg)
461{
462    return crypto_unregister_alg(&alg->halg.base);
463}
464EXPORT_SYMBOL_GPL(crypto_unregister_ahash);
465
466int ahash_register_instance(struct crypto_template *tmpl,
467                struct ahash_instance *inst)
468{
469    int err;
470
471    err = ahash_prepare_alg(&inst->alg);
472    if (err)
473        return err;
474
475    return crypto_register_instance(tmpl, ahash_crypto_instance(inst));
476}
477EXPORT_SYMBOL_GPL(ahash_register_instance);
478
479void ahash_free_instance(struct crypto_instance *inst)
480{
481    crypto_drop_spawn(crypto_instance_ctx(inst));
482    kfree(ahash_instance(inst));
483}
484EXPORT_SYMBOL_GPL(ahash_free_instance);
485
486int crypto_init_ahash_spawn(struct crypto_ahash_spawn *spawn,
487                struct hash_alg_common *alg,
488                struct crypto_instance *inst)
489{
490    return crypto_init_spawn2(&spawn->base, &alg->base, inst,
491                  &crypto_ahash_type);
492}
493EXPORT_SYMBOL_GPL(crypto_init_ahash_spawn);
494
495struct hash_alg_common *ahash_attr_alg(struct rtattr *rta, u32 type, u32 mask)
496{
497    struct crypto_alg *alg;
498
499    alg = crypto_attr_alg2(rta, &crypto_ahash_type, type, mask);
500    return IS_ERR(alg) ? ERR_CAST(alg) : __crypto_hash_alg_common(alg);
501}
502EXPORT_SYMBOL_GPL(ahash_attr_alg);
503
504MODULE_LICENSE("GPL");
505MODULE_DESCRIPTION("Asynchronous cryptographic hash type");
506

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