Root/crypto/shash.c

1/*
2 * Synchronous Cryptographic Hash operations.
3 *
4 * Copyright (c) 2008 Herbert Xu <herbert@gondor.apana.org.au>
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License as published by the Free
8 * Software Foundation; either version 2 of the License, or (at your option)
9 * any later version.
10 *
11 */
12
13#include <crypto/scatterwalk.h>
14#include <crypto/internal/hash.h>
15#include <linux/err.h>
16#include <linux/kernel.h>
17#include <linux/module.h>
18#include <linux/slab.h>
19#include <linux/seq_file.h>
20#include <linux/cryptouser.h>
21#include <net/netlink.h>
22
23#include "internal.h"
24
25static const struct crypto_type crypto_shash_type;
26
27static int shash_no_setkey(struct crypto_shash *tfm, const u8 *key,
28               unsigned int keylen)
29{
30    return -ENOSYS;
31}
32
33static int shash_setkey_unaligned(struct crypto_shash *tfm, const u8 *key,
34                  unsigned int keylen)
35{
36    struct shash_alg *shash = crypto_shash_alg(tfm);
37    unsigned long alignmask = crypto_shash_alignmask(tfm);
38    unsigned long absize;
39    u8 *buffer, *alignbuffer;
40    int err;
41
42    absize = keylen + (alignmask & ~(crypto_tfm_ctx_alignment() - 1));
43    buffer = kmalloc(absize, GFP_KERNEL);
44    if (!buffer)
45        return -ENOMEM;
46
47    alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
48    memcpy(alignbuffer, key, keylen);
49    err = shash->setkey(tfm, alignbuffer, keylen);
50    kzfree(buffer);
51    return err;
52}
53
54int crypto_shash_setkey(struct crypto_shash *tfm, const u8 *key,
55            unsigned int keylen)
56{
57    struct shash_alg *shash = crypto_shash_alg(tfm);
58    unsigned long alignmask = crypto_shash_alignmask(tfm);
59
60    if ((unsigned long)key & alignmask)
61        return shash_setkey_unaligned(tfm, key, keylen);
62
63    return shash->setkey(tfm, key, keylen);
64}
65EXPORT_SYMBOL_GPL(crypto_shash_setkey);
66
67static inline unsigned int shash_align_buffer_size(unsigned len,
68                           unsigned long mask)
69{
70    return len + (mask & ~(__alignof__(u8 __attribute__ ((aligned))) - 1));
71}
72
73static int shash_update_unaligned(struct shash_desc *desc, const u8 *data,
74                  unsigned int len)
75{
76    struct crypto_shash *tfm = desc->tfm;
77    struct shash_alg *shash = crypto_shash_alg(tfm);
78    unsigned long alignmask = crypto_shash_alignmask(tfm);
79    unsigned int unaligned_len = alignmask + 1 -
80                     ((unsigned long)data & alignmask);
81    u8 ubuf[shash_align_buffer_size(unaligned_len, alignmask)]
82        __attribute__ ((aligned));
83    u8 *buf = PTR_ALIGN(&ubuf[0], alignmask + 1);
84    int err;
85
86    if (unaligned_len > len)
87        unaligned_len = len;
88
89    memcpy(buf, data, unaligned_len);
90    err = shash->update(desc, buf, unaligned_len);
91    memset(buf, 0, unaligned_len);
92
93    return err ?:
94           shash->update(desc, data + unaligned_len, len - unaligned_len);
95}
96
97int crypto_shash_update(struct shash_desc *desc, const u8 *data,
98            unsigned int len)
99{
100    struct crypto_shash *tfm = desc->tfm;
101    struct shash_alg *shash = crypto_shash_alg(tfm);
102    unsigned long alignmask = crypto_shash_alignmask(tfm);
103
104    if ((unsigned long)data & alignmask)
105        return shash_update_unaligned(desc, data, len);
106
107    return shash->update(desc, data, len);
108}
109EXPORT_SYMBOL_GPL(crypto_shash_update);
110
111static int shash_final_unaligned(struct shash_desc *desc, u8 *out)
112{
113    struct crypto_shash *tfm = desc->tfm;
114    unsigned long alignmask = crypto_shash_alignmask(tfm);
115    struct shash_alg *shash = crypto_shash_alg(tfm);
116    unsigned int ds = crypto_shash_digestsize(tfm);
117    u8 ubuf[shash_align_buffer_size(ds, alignmask)]
118        __attribute__ ((aligned));
119    u8 *buf = PTR_ALIGN(&ubuf[0], alignmask + 1);
120    int err;
121
122    err = shash->final(desc, buf);
123    if (err)
124        goto out;
125
126    memcpy(out, buf, ds);
127
128out:
129    memset(buf, 0, ds);
130    return err;
131}
132
133int crypto_shash_final(struct shash_desc *desc, u8 *out)
134{
135    struct crypto_shash *tfm = desc->tfm;
136    struct shash_alg *shash = crypto_shash_alg(tfm);
137    unsigned long alignmask = crypto_shash_alignmask(tfm);
138
139    if ((unsigned long)out & alignmask)
140        return shash_final_unaligned(desc, out);
141
142    return shash->final(desc, out);
143}
144EXPORT_SYMBOL_GPL(crypto_shash_final);
145
146static int shash_finup_unaligned(struct shash_desc *desc, const u8 *data,
147                 unsigned int len, u8 *out)
148{
149    return crypto_shash_update(desc, data, len) ?:
150           crypto_shash_final(desc, out);
151}
152
153int crypto_shash_finup(struct shash_desc *desc, const u8 *data,
154               unsigned int len, u8 *out)
155{
156    struct crypto_shash *tfm = desc->tfm;
157    struct shash_alg *shash = crypto_shash_alg(tfm);
158    unsigned long alignmask = crypto_shash_alignmask(tfm);
159
160    if (((unsigned long)data | (unsigned long)out) & alignmask)
161        return shash_finup_unaligned(desc, data, len, out);
162
163    return shash->finup(desc, data, len, out);
164}
165EXPORT_SYMBOL_GPL(crypto_shash_finup);
166
167static int shash_digest_unaligned(struct shash_desc *desc, const u8 *data,
168                  unsigned int len, u8 *out)
169{
170    return crypto_shash_init(desc) ?:
171           crypto_shash_finup(desc, data, len, out);
172}
173
174int crypto_shash_digest(struct shash_desc *desc, const u8 *data,
175            unsigned int len, u8 *out)
176{
177    struct crypto_shash *tfm = desc->tfm;
178    struct shash_alg *shash = crypto_shash_alg(tfm);
179    unsigned long alignmask = crypto_shash_alignmask(tfm);
180
181    if (((unsigned long)data | (unsigned long)out) & alignmask)
182        return shash_digest_unaligned(desc, data, len, out);
183
184    return shash->digest(desc, data, len, out);
185}
186EXPORT_SYMBOL_GPL(crypto_shash_digest);
187
188static int shash_default_export(struct shash_desc *desc, void *out)
189{
190    memcpy(out, shash_desc_ctx(desc), crypto_shash_descsize(desc->tfm));
191    return 0;
192}
193
194static int shash_default_import(struct shash_desc *desc, const void *in)
195{
196    memcpy(shash_desc_ctx(desc), in, crypto_shash_descsize(desc->tfm));
197    return 0;
198}
199
200static int shash_async_setkey(struct crypto_ahash *tfm, const u8 *key,
201                  unsigned int keylen)
202{
203    struct crypto_shash **ctx = crypto_ahash_ctx(tfm);
204
205    return crypto_shash_setkey(*ctx, key, keylen);
206}
207
208static int shash_async_init(struct ahash_request *req)
209{
210    struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
211    struct shash_desc *desc = ahash_request_ctx(req);
212
213    desc->tfm = *ctx;
214    desc->flags = req->base.flags;
215
216    return crypto_shash_init(desc);
217}
218
219int shash_ahash_update(struct ahash_request *req, struct shash_desc *desc)
220{
221    struct crypto_hash_walk walk;
222    int nbytes;
223
224    for (nbytes = crypto_hash_walk_first(req, &walk); nbytes > 0;
225         nbytes = crypto_hash_walk_done(&walk, nbytes))
226        nbytes = crypto_shash_update(desc, walk.data, nbytes);
227
228    return nbytes;
229}
230EXPORT_SYMBOL_GPL(shash_ahash_update);
231
232static int shash_async_update(struct ahash_request *req)
233{
234    return shash_ahash_update(req, ahash_request_ctx(req));
235}
236
237static int shash_async_final(struct ahash_request *req)
238{
239    return crypto_shash_final(ahash_request_ctx(req), req->result);
240}
241
242int shash_ahash_finup(struct ahash_request *req, struct shash_desc *desc)
243{
244    struct crypto_hash_walk walk;
245    int nbytes;
246
247    nbytes = crypto_hash_walk_first(req, &walk);
248    if (!nbytes)
249        return crypto_shash_final(desc, req->result);
250
251    do {
252        nbytes = crypto_hash_walk_last(&walk) ?
253             crypto_shash_finup(desc, walk.data, nbytes,
254                        req->result) :
255             crypto_shash_update(desc, walk.data, nbytes);
256        nbytes = crypto_hash_walk_done(&walk, nbytes);
257    } while (nbytes > 0);
258
259    return nbytes;
260}
261EXPORT_SYMBOL_GPL(shash_ahash_finup);
262
263static int shash_async_finup(struct ahash_request *req)
264{
265    struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
266    struct shash_desc *desc = ahash_request_ctx(req);
267
268    desc->tfm = *ctx;
269    desc->flags = req->base.flags;
270
271    return shash_ahash_finup(req, desc);
272}
273
274int shash_ahash_digest(struct ahash_request *req, struct shash_desc *desc)
275{
276    struct scatterlist *sg = req->src;
277    unsigned int offset = sg->offset;
278    unsigned int nbytes = req->nbytes;
279    int err;
280
281    if (nbytes < min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset)) {
282        void *data;
283
284        data = kmap_atomic(sg_page(sg));
285        err = crypto_shash_digest(desc, data + offset, nbytes,
286                      req->result);
287        kunmap_atomic(data);
288        crypto_yield(desc->flags);
289    } else
290        err = crypto_shash_init(desc) ?:
291              shash_ahash_finup(req, desc);
292
293    return err;
294}
295EXPORT_SYMBOL_GPL(shash_ahash_digest);
296
297static int shash_async_digest(struct ahash_request *req)
298{
299    struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
300    struct shash_desc *desc = ahash_request_ctx(req);
301
302    desc->tfm = *ctx;
303    desc->flags = req->base.flags;
304
305    return shash_ahash_digest(req, desc);
306}
307
308static int shash_async_export(struct ahash_request *req, void *out)
309{
310    return crypto_shash_export(ahash_request_ctx(req), out);
311}
312
313static int shash_async_import(struct ahash_request *req, const void *in)
314{
315    struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
316    struct shash_desc *desc = ahash_request_ctx(req);
317
318    desc->tfm = *ctx;
319    desc->flags = req->base.flags;
320
321    return crypto_shash_import(desc, in);
322}
323
324static void crypto_exit_shash_ops_async(struct crypto_tfm *tfm)
325{
326    struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
327
328    crypto_free_shash(*ctx);
329}
330
331int crypto_init_shash_ops_async(struct crypto_tfm *tfm)
332{
333    struct crypto_alg *calg = tfm->__crt_alg;
334    struct shash_alg *alg = __crypto_shash_alg(calg);
335    struct crypto_ahash *crt = __crypto_ahash_cast(tfm);
336    struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
337    struct crypto_shash *shash;
338
339    if (!crypto_mod_get(calg))
340        return -EAGAIN;
341
342    shash = crypto_create_tfm(calg, &crypto_shash_type);
343    if (IS_ERR(shash)) {
344        crypto_mod_put(calg);
345        return PTR_ERR(shash);
346    }
347
348    *ctx = shash;
349    tfm->exit = crypto_exit_shash_ops_async;
350
351    crt->init = shash_async_init;
352    crt->update = shash_async_update;
353    crt->final = shash_async_final;
354    crt->finup = shash_async_finup;
355    crt->digest = shash_async_digest;
356
357    if (alg->setkey)
358        crt->setkey = shash_async_setkey;
359    if (alg->export)
360        crt->export = shash_async_export;
361    if (alg->import)
362        crt->import = shash_async_import;
363
364    crt->reqsize = sizeof(struct shash_desc) + crypto_shash_descsize(shash);
365
366    return 0;
367}
368
369static int shash_compat_setkey(struct crypto_hash *tfm, const u8 *key,
370                   unsigned int keylen)
371{
372    struct shash_desc **descp = crypto_hash_ctx(tfm);
373    struct shash_desc *desc = *descp;
374
375    return crypto_shash_setkey(desc->tfm, key, keylen);
376}
377
378static int shash_compat_init(struct hash_desc *hdesc)
379{
380    struct shash_desc **descp = crypto_hash_ctx(hdesc->tfm);
381    struct shash_desc *desc = *descp;
382
383    desc->flags = hdesc->flags;
384
385    return crypto_shash_init(desc);
386}
387
388static int shash_compat_update(struct hash_desc *hdesc, struct scatterlist *sg,
389                   unsigned int len)
390{
391    struct shash_desc **descp = crypto_hash_ctx(hdesc->tfm);
392    struct shash_desc *desc = *descp;
393    struct crypto_hash_walk walk;
394    int nbytes;
395
396    for (nbytes = crypto_hash_walk_first_compat(hdesc, &walk, sg, len);
397         nbytes > 0; nbytes = crypto_hash_walk_done(&walk, nbytes))
398        nbytes = crypto_shash_update(desc, walk.data, nbytes);
399
400    return nbytes;
401}
402
403static int shash_compat_final(struct hash_desc *hdesc, u8 *out)
404{
405    struct shash_desc **descp = crypto_hash_ctx(hdesc->tfm);
406
407    return crypto_shash_final(*descp, out);
408}
409
410static int shash_compat_digest(struct hash_desc *hdesc, struct scatterlist *sg,
411                   unsigned int nbytes, u8 *out)
412{
413    unsigned int offset = sg->offset;
414    int err;
415
416    if (nbytes < min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset)) {
417        struct shash_desc **descp = crypto_hash_ctx(hdesc->tfm);
418        struct shash_desc *desc = *descp;
419        void *data;
420
421        desc->flags = hdesc->flags;
422
423        data = kmap_atomic(sg_page(sg));
424        err = crypto_shash_digest(desc, data + offset, nbytes, out);
425        kunmap_atomic(data);
426        crypto_yield(desc->flags);
427        goto out;
428    }
429
430    err = shash_compat_init(hdesc);
431    if (err)
432        goto out;
433
434    err = shash_compat_update(hdesc, sg, nbytes);
435    if (err)
436        goto out;
437
438    err = shash_compat_final(hdesc, out);
439
440out:
441    return err;
442}
443
444static void crypto_exit_shash_ops_compat(struct crypto_tfm *tfm)
445{
446    struct shash_desc **descp = crypto_tfm_ctx(tfm);
447    struct shash_desc *desc = *descp;
448
449    crypto_free_shash(desc->tfm);
450    kzfree(desc);
451}
452
453static int crypto_init_shash_ops_compat(struct crypto_tfm *tfm)
454{
455    struct hash_tfm *crt = &tfm->crt_hash;
456    struct crypto_alg *calg = tfm->__crt_alg;
457    struct shash_alg *alg = __crypto_shash_alg(calg);
458    struct shash_desc **descp = crypto_tfm_ctx(tfm);
459    struct crypto_shash *shash;
460    struct shash_desc *desc;
461
462    if (!crypto_mod_get(calg))
463        return -EAGAIN;
464
465    shash = crypto_create_tfm(calg, &crypto_shash_type);
466    if (IS_ERR(shash)) {
467        crypto_mod_put(calg);
468        return PTR_ERR(shash);
469    }
470
471    desc = kmalloc(sizeof(*desc) + crypto_shash_descsize(shash),
472               GFP_KERNEL);
473    if (!desc) {
474        crypto_free_shash(shash);
475        return -ENOMEM;
476    }
477
478    *descp = desc;
479    desc->tfm = shash;
480    tfm->exit = crypto_exit_shash_ops_compat;
481
482    crt->init = shash_compat_init;
483    crt->update = shash_compat_update;
484    crt->final = shash_compat_final;
485    crt->digest = shash_compat_digest;
486    crt->setkey = shash_compat_setkey;
487
488    crt->digestsize = alg->digestsize;
489
490    return 0;
491}
492
493static int crypto_init_shash_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
494{
495    switch (mask & CRYPTO_ALG_TYPE_MASK) {
496    case CRYPTO_ALG_TYPE_HASH_MASK:
497        return crypto_init_shash_ops_compat(tfm);
498    }
499
500    return -EINVAL;
501}
502
503static unsigned int crypto_shash_ctxsize(struct crypto_alg *alg, u32 type,
504                     u32 mask)
505{
506    switch (mask & CRYPTO_ALG_TYPE_MASK) {
507    case CRYPTO_ALG_TYPE_HASH_MASK:
508        return sizeof(struct shash_desc *);
509    }
510
511    return 0;
512}
513
514static int crypto_shash_init_tfm(struct crypto_tfm *tfm)
515{
516    struct crypto_shash *hash = __crypto_shash_cast(tfm);
517
518    hash->descsize = crypto_shash_alg(hash)->descsize;
519    return 0;
520}
521
522static unsigned int crypto_shash_extsize(struct crypto_alg *alg)
523{
524    return alg->cra_ctxsize;
525}
526
527#ifdef CONFIG_NET
528static int crypto_shash_report(struct sk_buff *skb, struct crypto_alg *alg)
529{
530    struct crypto_report_hash rhash;
531    struct shash_alg *salg = __crypto_shash_alg(alg);
532
533    strncpy(rhash.type, "shash", sizeof(rhash.type));
534
535    rhash.blocksize = alg->cra_blocksize;
536    rhash.digestsize = salg->digestsize;
537
538    if (nla_put(skb, CRYPTOCFGA_REPORT_HASH,
539            sizeof(struct crypto_report_hash), &rhash))
540        goto nla_put_failure;
541    return 0;
542
543nla_put_failure:
544    return -EMSGSIZE;
545}
546#else
547static int crypto_shash_report(struct sk_buff *skb, struct crypto_alg *alg)
548{
549    return -ENOSYS;
550}
551#endif
552
553static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
554    __attribute__ ((unused));
555static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
556{
557    struct shash_alg *salg = __crypto_shash_alg(alg);
558
559    seq_printf(m, "type : shash\n");
560    seq_printf(m, "blocksize : %u\n", alg->cra_blocksize);
561    seq_printf(m, "digestsize : %u\n", salg->digestsize);
562}
563
564static const struct crypto_type crypto_shash_type = {
565    .ctxsize = crypto_shash_ctxsize,
566    .extsize = crypto_shash_extsize,
567    .init = crypto_init_shash_ops,
568    .init_tfm = crypto_shash_init_tfm,
569#ifdef CONFIG_PROC_FS
570    .show = crypto_shash_show,
571#endif
572    .report = crypto_shash_report,
573    .maskclear = ~CRYPTO_ALG_TYPE_MASK,
574    .maskset = CRYPTO_ALG_TYPE_MASK,
575    .type = CRYPTO_ALG_TYPE_SHASH,
576    .tfmsize = offsetof(struct crypto_shash, base),
577};
578
579struct crypto_shash *crypto_alloc_shash(const char *alg_name, u32 type,
580                    u32 mask)
581{
582    return crypto_alloc_tfm(alg_name, &crypto_shash_type, type, mask);
583}
584EXPORT_SYMBOL_GPL(crypto_alloc_shash);
585
586static int shash_prepare_alg(struct shash_alg *alg)
587{
588    struct crypto_alg *base = &alg->base;
589
590    if (alg->digestsize > PAGE_SIZE / 8 ||
591        alg->descsize > PAGE_SIZE / 8 ||
592        alg->statesize > PAGE_SIZE / 8)
593        return -EINVAL;
594
595    base->cra_type = &crypto_shash_type;
596    base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
597    base->cra_flags |= CRYPTO_ALG_TYPE_SHASH;
598
599    if (!alg->finup)
600        alg->finup = shash_finup_unaligned;
601    if (!alg->digest)
602        alg->digest = shash_digest_unaligned;
603    if (!alg->export) {
604        alg->export = shash_default_export;
605        alg->import = shash_default_import;
606        alg->statesize = alg->descsize;
607    }
608    if (!alg->setkey)
609        alg->setkey = shash_no_setkey;
610
611    return 0;
612}
613
614int crypto_register_shash(struct shash_alg *alg)
615{
616    struct crypto_alg *base = &alg->base;
617    int err;
618
619    err = shash_prepare_alg(alg);
620    if (err)
621        return err;
622
623    return crypto_register_alg(base);
624}
625EXPORT_SYMBOL_GPL(crypto_register_shash);
626
627int crypto_unregister_shash(struct shash_alg *alg)
628{
629    return crypto_unregister_alg(&alg->base);
630}
631EXPORT_SYMBOL_GPL(crypto_unregister_shash);
632
633int crypto_register_shashes(struct shash_alg *algs, int count)
634{
635    int i, ret;
636
637    for (i = 0; i < count; i++) {
638        ret = crypto_register_shash(&algs[i]);
639        if (ret)
640            goto err;
641    }
642
643    return 0;
644
645err:
646    for (--i; i >= 0; --i)
647        crypto_unregister_shash(&algs[i]);
648
649    return ret;
650}
651EXPORT_SYMBOL_GPL(crypto_register_shashes);
652
653int crypto_unregister_shashes(struct shash_alg *algs, int count)
654{
655    int i, ret;
656
657    for (i = count - 1; i >= 0; --i) {
658        ret = crypto_unregister_shash(&algs[i]);
659        if (ret)
660            pr_err("Failed to unregister %s %s: %d\n",
661                   algs[i].base.cra_driver_name,
662                   algs[i].base.cra_name, ret);
663    }
664
665    return 0;
666}
667EXPORT_SYMBOL_GPL(crypto_unregister_shashes);
668
669int shash_register_instance(struct crypto_template *tmpl,
670                struct shash_instance *inst)
671{
672    int err;
673
674    err = shash_prepare_alg(&inst->alg);
675    if (err)
676        return err;
677
678    return crypto_register_instance(tmpl, shash_crypto_instance(inst));
679}
680EXPORT_SYMBOL_GPL(shash_register_instance);
681
682void shash_free_instance(struct crypto_instance *inst)
683{
684    crypto_drop_spawn(crypto_instance_ctx(inst));
685    kfree(shash_instance(inst));
686}
687EXPORT_SYMBOL_GPL(shash_free_instance);
688
689int crypto_init_shash_spawn(struct crypto_shash_spawn *spawn,
690                struct shash_alg *alg,
691                struct crypto_instance *inst)
692{
693    return crypto_init_spawn2(&spawn->base, &alg->base, inst,
694                  &crypto_shash_type);
695}
696EXPORT_SYMBOL_GPL(crypto_init_shash_spawn);
697
698struct shash_alg *shash_attr_alg(struct rtattr *rta, u32 type, u32 mask)
699{
700    struct crypto_alg *alg;
701
702    alg = crypto_attr_alg2(rta, &crypto_shash_type, type, mask);
703    return IS_ERR(alg) ? ERR_CAST(alg) :
704           container_of(alg, struct shash_alg, base);
705}
706EXPORT_SYMBOL_GPL(shash_attr_alg);
707
708MODULE_LICENSE("GPL");
709MODULE_DESCRIPTION("Synchronous cryptographic hash type");
710

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