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    typedef u8 __attribute__ ((aligned)) u8_aligned;
71    return len + (mask & ~(__alignof__(u8_aligned) - 1));
72}
73
74static int shash_update_unaligned(struct shash_desc *desc, const u8 *data,
75                  unsigned int len)
76{
77    struct crypto_shash *tfm = desc->tfm;
78    struct shash_alg *shash = crypto_shash_alg(tfm);
79    unsigned long alignmask = crypto_shash_alignmask(tfm);
80    unsigned int unaligned_len = alignmask + 1 -
81                     ((unsigned long)data & alignmask);
82    u8 ubuf[shash_align_buffer_size(unaligned_len, alignmask)]
83        __attribute__ ((aligned));
84    u8 *buf = PTR_ALIGN(&ubuf[0], alignmask + 1);
85    int err;
86
87    if (unaligned_len > len)
88        unaligned_len = len;
89
90    memcpy(buf, data, unaligned_len);
91    err = shash->update(desc, buf, unaligned_len);
92    memset(buf, 0, unaligned_len);
93
94    return err ?:
95           shash->update(desc, data + unaligned_len, len - unaligned_len);
96}
97
98int crypto_shash_update(struct shash_desc *desc, const u8 *data,
99            unsigned int len)
100{
101    struct crypto_shash *tfm = desc->tfm;
102    struct shash_alg *shash = crypto_shash_alg(tfm);
103    unsigned long alignmask = crypto_shash_alignmask(tfm);
104
105    if ((unsigned long)data & alignmask)
106        return shash_update_unaligned(desc, data, len);
107
108    return shash->update(desc, data, len);
109}
110EXPORT_SYMBOL_GPL(crypto_shash_update);
111
112static int shash_final_unaligned(struct shash_desc *desc, u8 *out)
113{
114    struct crypto_shash *tfm = desc->tfm;
115    unsigned long alignmask = crypto_shash_alignmask(tfm);
116    struct shash_alg *shash = crypto_shash_alg(tfm);
117    unsigned int ds = crypto_shash_digestsize(tfm);
118    u8 ubuf[shash_align_buffer_size(ds, alignmask)]
119        __attribute__ ((aligned));
120    u8 *buf = PTR_ALIGN(&ubuf[0], alignmask + 1);
121    int err;
122
123    err = shash->final(desc, buf);
124    if (err)
125        goto out;
126
127    memcpy(out, buf, ds);
128
129out:
130    memset(buf, 0, ds);
131    return err;
132}
133
134int crypto_shash_final(struct shash_desc *desc, u8 *out)
135{
136    struct crypto_shash *tfm = desc->tfm;
137    struct shash_alg *shash = crypto_shash_alg(tfm);
138    unsigned long alignmask = crypto_shash_alignmask(tfm);
139
140    if ((unsigned long)out & alignmask)
141        return shash_final_unaligned(desc, out);
142
143    return shash->final(desc, out);
144}
145EXPORT_SYMBOL_GPL(crypto_shash_final);
146
147static int shash_finup_unaligned(struct shash_desc *desc, const u8 *data,
148                 unsigned int len, u8 *out)
149{
150    return crypto_shash_update(desc, data, len) ?:
151           crypto_shash_final(desc, out);
152}
153
154int crypto_shash_finup(struct shash_desc *desc, const u8 *data,
155               unsigned int len, u8 *out)
156{
157    struct crypto_shash *tfm = desc->tfm;
158    struct shash_alg *shash = crypto_shash_alg(tfm);
159    unsigned long alignmask = crypto_shash_alignmask(tfm);
160
161    if (((unsigned long)data | (unsigned long)out) & alignmask)
162        return shash_finup_unaligned(desc, data, len, out);
163
164    return shash->finup(desc, data, len, out);
165}
166EXPORT_SYMBOL_GPL(crypto_shash_finup);
167
168static int shash_digest_unaligned(struct shash_desc *desc, const u8 *data,
169                  unsigned int len, u8 *out)
170{
171    return crypto_shash_init(desc) ?:
172           crypto_shash_finup(desc, data, len, out);
173}
174
175int crypto_shash_digest(struct shash_desc *desc, const u8 *data,
176            unsigned int len, u8 *out)
177{
178    struct crypto_shash *tfm = desc->tfm;
179    struct shash_alg *shash = crypto_shash_alg(tfm);
180    unsigned long alignmask = crypto_shash_alignmask(tfm);
181
182    if (((unsigned long)data | (unsigned long)out) & alignmask)
183        return shash_digest_unaligned(desc, data, len, out);
184
185    return shash->digest(desc, data, len, out);
186}
187EXPORT_SYMBOL_GPL(crypto_shash_digest);
188
189static int shash_default_export(struct shash_desc *desc, void *out)
190{
191    memcpy(out, shash_desc_ctx(desc), crypto_shash_descsize(desc->tfm));
192    return 0;
193}
194
195static int shash_default_import(struct shash_desc *desc, const void *in)
196{
197    memcpy(shash_desc_ctx(desc), in, crypto_shash_descsize(desc->tfm));
198    return 0;
199}
200
201static int shash_async_setkey(struct crypto_ahash *tfm, const u8 *key,
202                  unsigned int keylen)
203{
204    struct crypto_shash **ctx = crypto_ahash_ctx(tfm);
205
206    return crypto_shash_setkey(*ctx, key, keylen);
207}
208
209static int shash_async_init(struct ahash_request *req)
210{
211    struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
212    struct shash_desc *desc = ahash_request_ctx(req);
213
214    desc->tfm = *ctx;
215    desc->flags = req->base.flags;
216
217    return crypto_shash_init(desc);
218}
219
220int shash_ahash_update(struct ahash_request *req, struct shash_desc *desc)
221{
222    struct crypto_hash_walk walk;
223    int nbytes;
224
225    for (nbytes = crypto_hash_walk_first(req, &walk); nbytes > 0;
226         nbytes = crypto_hash_walk_done(&walk, nbytes))
227        nbytes = crypto_shash_update(desc, walk.data, nbytes);
228
229    return nbytes;
230}
231EXPORT_SYMBOL_GPL(shash_ahash_update);
232
233static int shash_async_update(struct ahash_request *req)
234{
235    return shash_ahash_update(req, ahash_request_ctx(req));
236}
237
238static int shash_async_final(struct ahash_request *req)
239{
240    return crypto_shash_final(ahash_request_ctx(req), req->result);
241}
242
243int shash_ahash_finup(struct ahash_request *req, struct shash_desc *desc)
244{
245    struct crypto_hash_walk walk;
246    int nbytes;
247
248    nbytes = crypto_hash_walk_first(req, &walk);
249    if (!nbytes)
250        return crypto_shash_final(desc, req->result);
251
252    do {
253        nbytes = crypto_hash_walk_last(&walk) ?
254             crypto_shash_finup(desc, walk.data, nbytes,
255                        req->result) :
256             crypto_shash_update(desc, walk.data, nbytes);
257        nbytes = crypto_hash_walk_done(&walk, nbytes);
258    } while (nbytes > 0);
259
260    return nbytes;
261}
262EXPORT_SYMBOL_GPL(shash_ahash_finup);
263
264static int shash_async_finup(struct ahash_request *req)
265{
266    struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
267    struct shash_desc *desc = ahash_request_ctx(req);
268
269    desc->tfm = *ctx;
270    desc->flags = req->base.flags;
271
272    return shash_ahash_finup(req, desc);
273}
274
275int shash_ahash_digest(struct ahash_request *req, struct shash_desc *desc)
276{
277    struct scatterlist *sg = req->src;
278    unsigned int offset = sg->offset;
279    unsigned int nbytes = req->nbytes;
280    int err;
281
282    if (nbytes < min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset)) {
283        void *data;
284
285        data = kmap_atomic(sg_page(sg));
286        err = crypto_shash_digest(desc, data + offset, nbytes,
287                      req->result);
288        kunmap_atomic(data);
289        crypto_yield(desc->flags);
290    } else
291        err = crypto_shash_init(desc) ?:
292              shash_ahash_finup(req, desc);
293
294    return err;
295}
296EXPORT_SYMBOL_GPL(shash_ahash_digest);
297
298static int shash_async_digest(struct ahash_request *req)
299{
300    struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
301    struct shash_desc *desc = ahash_request_ctx(req);
302
303    desc->tfm = *ctx;
304    desc->flags = req->base.flags;
305
306    return shash_ahash_digest(req, desc);
307}
308
309static int shash_async_export(struct ahash_request *req, void *out)
310{
311    return crypto_shash_export(ahash_request_ctx(req), out);
312}
313
314static int shash_async_import(struct ahash_request *req, const void *in)
315{
316    struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
317    struct shash_desc *desc = ahash_request_ctx(req);
318
319    desc->tfm = *ctx;
320    desc->flags = req->base.flags;
321
322    return crypto_shash_import(desc, in);
323}
324
325static void crypto_exit_shash_ops_async(struct crypto_tfm *tfm)
326{
327    struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
328
329    crypto_free_shash(*ctx);
330}
331
332int crypto_init_shash_ops_async(struct crypto_tfm *tfm)
333{
334    struct crypto_alg *calg = tfm->__crt_alg;
335    struct shash_alg *alg = __crypto_shash_alg(calg);
336    struct crypto_ahash *crt = __crypto_ahash_cast(tfm);
337    struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
338    struct crypto_shash *shash;
339
340    if (!crypto_mod_get(calg))
341        return -EAGAIN;
342
343    shash = crypto_create_tfm(calg, &crypto_shash_type);
344    if (IS_ERR(shash)) {
345        crypto_mod_put(calg);
346        return PTR_ERR(shash);
347    }
348
349    *ctx = shash;
350    tfm->exit = crypto_exit_shash_ops_async;
351
352    crt->init = shash_async_init;
353    crt->update = shash_async_update;
354    crt->final = shash_async_final;
355    crt->finup = shash_async_finup;
356    crt->digest = shash_async_digest;
357
358    if (alg->setkey)
359        crt->setkey = shash_async_setkey;
360    if (alg->export)
361        crt->export = shash_async_export;
362    if (alg->import)
363        crt->import = shash_async_import;
364
365    crt->reqsize = sizeof(struct shash_desc) + crypto_shash_descsize(shash);
366
367    return 0;
368}
369
370static int shash_compat_setkey(struct crypto_hash *tfm, const u8 *key,
371                   unsigned int keylen)
372{
373    struct shash_desc **descp = crypto_hash_ctx(tfm);
374    struct shash_desc *desc = *descp;
375
376    return crypto_shash_setkey(desc->tfm, key, keylen);
377}
378
379static int shash_compat_init(struct hash_desc *hdesc)
380{
381    struct shash_desc **descp = crypto_hash_ctx(hdesc->tfm);
382    struct shash_desc *desc = *descp;
383
384    desc->flags = hdesc->flags;
385
386    return crypto_shash_init(desc);
387}
388
389static int shash_compat_update(struct hash_desc *hdesc, struct scatterlist *sg,
390                   unsigned int len)
391{
392    struct shash_desc **descp = crypto_hash_ctx(hdesc->tfm);
393    struct shash_desc *desc = *descp;
394    struct crypto_hash_walk walk;
395    int nbytes;
396
397    for (nbytes = crypto_hash_walk_first_compat(hdesc, &walk, sg, len);
398         nbytes > 0; nbytes = crypto_hash_walk_done(&walk, nbytes))
399        nbytes = crypto_shash_update(desc, walk.data, nbytes);
400
401    return nbytes;
402}
403
404static int shash_compat_final(struct hash_desc *hdesc, u8 *out)
405{
406    struct shash_desc **descp = crypto_hash_ctx(hdesc->tfm);
407
408    return crypto_shash_final(*descp, out);
409}
410
411static int shash_compat_digest(struct hash_desc *hdesc, struct scatterlist *sg,
412                   unsigned int nbytes, u8 *out)
413{
414    unsigned int offset = sg->offset;
415    int err;
416
417    if (nbytes < min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset)) {
418        struct shash_desc **descp = crypto_hash_ctx(hdesc->tfm);
419        struct shash_desc *desc = *descp;
420        void *data;
421
422        desc->flags = hdesc->flags;
423
424        data = kmap_atomic(sg_page(sg));
425        err = crypto_shash_digest(desc, data + offset, nbytes, out);
426        kunmap_atomic(data);
427        crypto_yield(desc->flags);
428        goto out;
429    }
430
431    err = shash_compat_init(hdesc);
432    if (err)
433        goto out;
434
435    err = shash_compat_update(hdesc, sg, nbytes);
436    if (err)
437        goto out;
438
439    err = shash_compat_final(hdesc, out);
440
441out:
442    return err;
443}
444
445static void crypto_exit_shash_ops_compat(struct crypto_tfm *tfm)
446{
447    struct shash_desc **descp = crypto_tfm_ctx(tfm);
448    struct shash_desc *desc = *descp;
449
450    crypto_free_shash(desc->tfm);
451    kzfree(desc);
452}
453
454static int crypto_init_shash_ops_compat(struct crypto_tfm *tfm)
455{
456    struct hash_tfm *crt = &tfm->crt_hash;
457    struct crypto_alg *calg = tfm->__crt_alg;
458    struct shash_alg *alg = __crypto_shash_alg(calg);
459    struct shash_desc **descp = crypto_tfm_ctx(tfm);
460    struct crypto_shash *shash;
461    struct shash_desc *desc;
462
463    if (!crypto_mod_get(calg))
464        return -EAGAIN;
465
466    shash = crypto_create_tfm(calg, &crypto_shash_type);
467    if (IS_ERR(shash)) {
468        crypto_mod_put(calg);
469        return PTR_ERR(shash);
470    }
471
472    desc = kmalloc(sizeof(*desc) + crypto_shash_descsize(shash),
473               GFP_KERNEL);
474    if (!desc) {
475        crypto_free_shash(shash);
476        return -ENOMEM;
477    }
478
479    *descp = desc;
480    desc->tfm = shash;
481    tfm->exit = crypto_exit_shash_ops_compat;
482
483    crt->init = shash_compat_init;
484    crt->update = shash_compat_update;
485    crt->final = shash_compat_final;
486    crt->digest = shash_compat_digest;
487    crt->setkey = shash_compat_setkey;
488
489    crt->digestsize = alg->digestsize;
490
491    return 0;
492}
493
494static int crypto_init_shash_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
495{
496    switch (mask & CRYPTO_ALG_TYPE_MASK) {
497    case CRYPTO_ALG_TYPE_HASH_MASK:
498        return crypto_init_shash_ops_compat(tfm);
499    }
500
501    return -EINVAL;
502}
503
504static unsigned int crypto_shash_ctxsize(struct crypto_alg *alg, u32 type,
505                     u32 mask)
506{
507    switch (mask & CRYPTO_ALG_TYPE_MASK) {
508    case CRYPTO_ALG_TYPE_HASH_MASK:
509        return sizeof(struct shash_desc *);
510    }
511
512    return 0;
513}
514
515static int crypto_shash_init_tfm(struct crypto_tfm *tfm)
516{
517    struct crypto_shash *hash = __crypto_shash_cast(tfm);
518
519    hash->descsize = crypto_shash_alg(hash)->descsize;
520    return 0;
521}
522
523static unsigned int crypto_shash_extsize(struct crypto_alg *alg)
524{
525    return alg->cra_ctxsize;
526}
527
528#ifdef CONFIG_NET
529static int crypto_shash_report(struct sk_buff *skb, struct crypto_alg *alg)
530{
531    struct crypto_report_hash rhash;
532    struct shash_alg *salg = __crypto_shash_alg(alg);
533
534    strncpy(rhash.type, "shash", sizeof(rhash.type));
535
536    rhash.blocksize = alg->cra_blocksize;
537    rhash.digestsize = salg->digestsize;
538
539    if (nla_put(skb, CRYPTOCFGA_REPORT_HASH,
540            sizeof(struct crypto_report_hash), &rhash))
541        goto nla_put_failure;
542    return 0;
543
544nla_put_failure:
545    return -EMSGSIZE;
546}
547#else
548static int crypto_shash_report(struct sk_buff *skb, struct crypto_alg *alg)
549{
550    return -ENOSYS;
551}
552#endif
553
554static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
555    __attribute__ ((unused));
556static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
557{
558    struct shash_alg *salg = __crypto_shash_alg(alg);
559
560    seq_printf(m, "type : shash\n");
561    seq_printf(m, "blocksize : %u\n", alg->cra_blocksize);
562    seq_printf(m, "digestsize : %u\n", salg->digestsize);
563}
564
565static const struct crypto_type crypto_shash_type = {
566    .ctxsize = crypto_shash_ctxsize,
567    .extsize = crypto_shash_extsize,
568    .init = crypto_init_shash_ops,
569    .init_tfm = crypto_shash_init_tfm,
570#ifdef CONFIG_PROC_FS
571    .show = crypto_shash_show,
572#endif
573    .report = crypto_shash_report,
574    .maskclear = ~CRYPTO_ALG_TYPE_MASK,
575    .maskset = CRYPTO_ALG_TYPE_MASK,
576    .type = CRYPTO_ALG_TYPE_SHASH,
577    .tfmsize = offsetof(struct crypto_shash, base),
578};
579
580struct crypto_shash *crypto_alloc_shash(const char *alg_name, u32 type,
581                    u32 mask)
582{
583    return crypto_alloc_tfm(alg_name, &crypto_shash_type, type, mask);
584}
585EXPORT_SYMBOL_GPL(crypto_alloc_shash);
586
587static int shash_prepare_alg(struct shash_alg *alg)
588{
589    struct crypto_alg *base = &alg->base;
590
591    if (alg->digestsize > PAGE_SIZE / 8 ||
592        alg->descsize > PAGE_SIZE / 8 ||
593        alg->statesize > PAGE_SIZE / 8)
594        return -EINVAL;
595
596    base->cra_type = &crypto_shash_type;
597    base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
598    base->cra_flags |= CRYPTO_ALG_TYPE_SHASH;
599
600    if (!alg->finup)
601        alg->finup = shash_finup_unaligned;
602    if (!alg->digest)
603        alg->digest = shash_digest_unaligned;
604    if (!alg->export) {
605        alg->export = shash_default_export;
606        alg->import = shash_default_import;
607        alg->statesize = alg->descsize;
608    }
609    if (!alg->setkey)
610        alg->setkey = shash_no_setkey;
611
612    return 0;
613}
614
615int crypto_register_shash(struct shash_alg *alg)
616{
617    struct crypto_alg *base = &alg->base;
618    int err;
619
620    err = shash_prepare_alg(alg);
621    if (err)
622        return err;
623
624    return crypto_register_alg(base);
625}
626EXPORT_SYMBOL_GPL(crypto_register_shash);
627
628int crypto_unregister_shash(struct shash_alg *alg)
629{
630    return crypto_unregister_alg(&alg->base);
631}
632EXPORT_SYMBOL_GPL(crypto_unregister_shash);
633
634int crypto_register_shashes(struct shash_alg *algs, int count)
635{
636    int i, ret;
637
638    for (i = 0; i < count; i++) {
639        ret = crypto_register_shash(&algs[i]);
640        if (ret)
641            goto err;
642    }
643
644    return 0;
645
646err:
647    for (--i; i >= 0; --i)
648        crypto_unregister_shash(&algs[i]);
649
650    return ret;
651}
652EXPORT_SYMBOL_GPL(crypto_register_shashes);
653
654int crypto_unregister_shashes(struct shash_alg *algs, int count)
655{
656    int i, ret;
657
658    for (i = count - 1; i >= 0; --i) {
659        ret = crypto_unregister_shash(&algs[i]);
660        if (ret)
661            pr_err("Failed to unregister %s %s: %d\n",
662                   algs[i].base.cra_driver_name,
663                   algs[i].base.cra_name, ret);
664    }
665
666    return 0;
667}
668EXPORT_SYMBOL_GPL(crypto_unregister_shashes);
669
670int shash_register_instance(struct crypto_template *tmpl,
671                struct shash_instance *inst)
672{
673    int err;
674
675    err = shash_prepare_alg(&inst->alg);
676    if (err)
677        return err;
678
679    return crypto_register_instance(tmpl, shash_crypto_instance(inst));
680}
681EXPORT_SYMBOL_GPL(shash_register_instance);
682
683void shash_free_instance(struct crypto_instance *inst)
684{
685    crypto_drop_spawn(crypto_instance_ctx(inst));
686    kfree(shash_instance(inst));
687}
688EXPORT_SYMBOL_GPL(shash_free_instance);
689
690int crypto_init_shash_spawn(struct crypto_shash_spawn *spawn,
691                struct shash_alg *alg,
692                struct crypto_instance *inst)
693{
694    return crypto_init_spawn2(&spawn->base, &alg->base, inst,
695                  &crypto_shash_type);
696}
697EXPORT_SYMBOL_GPL(crypto_init_shash_spawn);
698
699struct shash_alg *shash_attr_alg(struct rtattr *rta, u32 type, u32 mask)
700{
701    struct crypto_alg *alg;
702
703    alg = crypto_attr_alg2(rta, &crypto_shash_type, type, mask);
704    return IS_ERR(alg) ? ERR_CAST(alg) :
705           container_of(alg, struct shash_alg, base);
706}
707EXPORT_SYMBOL_GPL(shash_attr_alg);
708
709MODULE_LICENSE("GPL");
710MODULE_DESCRIPTION("Synchronous cryptographic hash type");
711

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