Root/crypto/aead.c

1/*
2 * AEAD: Authenticated Encryption with Associated Data
3 *
4 * This file provides API support for AEAD algorithms.
5 *
6 * Copyright (c) 2007 Herbert Xu <herbert@gondor.apana.org.au>
7 *
8 * This program is free software; you can redistribute it and/or modify it
9 * under the terms of the GNU General Public License as published by the Free
10 * Software Foundation; either version 2 of the License, or (at your option)
11 * any later version.
12 *
13 */
14
15#include <crypto/internal/aead.h>
16#include <linux/err.h>
17#include <linux/init.h>
18#include <linux/kernel.h>
19#include <linux/module.h>
20#include <linux/rtnetlink.h>
21#include <linux/sched.h>
22#include <linux/slab.h>
23#include <linux/seq_file.h>
24#include <linux/cryptouser.h>
25#include <net/netlink.h>
26
27#include "internal.h"
28
29static int setkey_unaligned(struct crypto_aead *tfm, const u8 *key,
30                unsigned int keylen)
31{
32    struct aead_alg *aead = crypto_aead_alg(tfm);
33    unsigned long alignmask = crypto_aead_alignmask(tfm);
34    int ret;
35    u8 *buffer, *alignbuffer;
36    unsigned long absize;
37
38    absize = keylen + alignmask;
39    buffer = kmalloc(absize, GFP_ATOMIC);
40    if (!buffer)
41        return -ENOMEM;
42
43    alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
44    memcpy(alignbuffer, key, keylen);
45    ret = aead->setkey(tfm, alignbuffer, keylen);
46    memset(alignbuffer, 0, keylen);
47    kfree(buffer);
48    return ret;
49}
50
51static int setkey(struct crypto_aead *tfm, const u8 *key, unsigned int keylen)
52{
53    struct aead_alg *aead = crypto_aead_alg(tfm);
54    unsigned long alignmask = crypto_aead_alignmask(tfm);
55
56    if ((unsigned long)key & alignmask)
57        return setkey_unaligned(tfm, key, keylen);
58
59    return aead->setkey(tfm, key, keylen);
60}
61
62int crypto_aead_setauthsize(struct crypto_aead *tfm, unsigned int authsize)
63{
64    struct aead_tfm *crt = crypto_aead_crt(tfm);
65    int err;
66
67    if (authsize > crypto_aead_alg(tfm)->maxauthsize)
68        return -EINVAL;
69
70    if (crypto_aead_alg(tfm)->setauthsize) {
71        err = crypto_aead_alg(tfm)->setauthsize(crt->base, authsize);
72        if (err)
73            return err;
74    }
75
76    crypto_aead_crt(crt->base)->authsize = authsize;
77    crt->authsize = authsize;
78    return 0;
79}
80EXPORT_SYMBOL_GPL(crypto_aead_setauthsize);
81
82static unsigned int crypto_aead_ctxsize(struct crypto_alg *alg, u32 type,
83                    u32 mask)
84{
85    return alg->cra_ctxsize;
86}
87
88static int no_givcrypt(struct aead_givcrypt_request *req)
89{
90    return -ENOSYS;
91}
92
93static int crypto_init_aead_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
94{
95    struct aead_alg *alg = &tfm->__crt_alg->cra_aead;
96    struct aead_tfm *crt = &tfm->crt_aead;
97
98    if (max(alg->maxauthsize, alg->ivsize) > PAGE_SIZE / 8)
99        return -EINVAL;
100
101    crt->setkey = tfm->__crt_alg->cra_flags & CRYPTO_ALG_GENIV ?
102              alg->setkey : setkey;
103    crt->encrypt = alg->encrypt;
104    crt->decrypt = alg->decrypt;
105    crt->givencrypt = alg->givencrypt ?: no_givcrypt;
106    crt->givdecrypt = alg->givdecrypt ?: no_givcrypt;
107    crt->base = __crypto_aead_cast(tfm);
108    crt->ivsize = alg->ivsize;
109    crt->authsize = alg->maxauthsize;
110
111    return 0;
112}
113
114#ifdef CONFIG_NET
115static int crypto_aead_report(struct sk_buff *skb, struct crypto_alg *alg)
116{
117    struct crypto_report_aead raead;
118    struct aead_alg *aead = &alg->cra_aead;
119
120    strncpy(raead.type, "aead", sizeof(raead.type));
121    strncpy(raead.geniv, aead->geniv ?: "<built-in>", sizeof(raead.geniv));
122
123    raead.blocksize = alg->cra_blocksize;
124    raead.maxauthsize = aead->maxauthsize;
125    raead.ivsize = aead->ivsize;
126
127    if (nla_put(skb, CRYPTOCFGA_REPORT_AEAD,
128            sizeof(struct crypto_report_aead), &raead))
129        goto nla_put_failure;
130    return 0;
131
132nla_put_failure:
133    return -EMSGSIZE;
134}
135#else
136static int crypto_aead_report(struct sk_buff *skb, struct crypto_alg *alg)
137{
138    return -ENOSYS;
139}
140#endif
141
142static void crypto_aead_show(struct seq_file *m, struct crypto_alg *alg)
143    __attribute__ ((unused));
144static void crypto_aead_show(struct seq_file *m, struct crypto_alg *alg)
145{
146    struct aead_alg *aead = &alg->cra_aead;
147
148    seq_printf(m, "type : aead\n");
149    seq_printf(m, "async : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
150                         "yes" : "no");
151    seq_printf(m, "blocksize : %u\n", alg->cra_blocksize);
152    seq_printf(m, "ivsize : %u\n", aead->ivsize);
153    seq_printf(m, "maxauthsize : %u\n", aead->maxauthsize);
154    seq_printf(m, "geniv : %s\n", aead->geniv ?: "<built-in>");
155}
156
157const struct crypto_type crypto_aead_type = {
158    .ctxsize = crypto_aead_ctxsize,
159    .init = crypto_init_aead_ops,
160#ifdef CONFIG_PROC_FS
161    .show = crypto_aead_show,
162#endif
163    .report = crypto_aead_report,
164};
165EXPORT_SYMBOL_GPL(crypto_aead_type);
166
167static int aead_null_givencrypt(struct aead_givcrypt_request *req)
168{
169    return crypto_aead_encrypt(&req->areq);
170}
171
172static int aead_null_givdecrypt(struct aead_givcrypt_request *req)
173{
174    return crypto_aead_decrypt(&req->areq);
175}
176
177static int crypto_init_nivaead_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
178{
179    struct aead_alg *alg = &tfm->__crt_alg->cra_aead;
180    struct aead_tfm *crt = &tfm->crt_aead;
181
182    if (max(alg->maxauthsize, alg->ivsize) > PAGE_SIZE / 8)
183        return -EINVAL;
184
185    crt->setkey = setkey;
186    crt->encrypt = alg->encrypt;
187    crt->decrypt = alg->decrypt;
188    if (!alg->ivsize) {
189        crt->givencrypt = aead_null_givencrypt;
190        crt->givdecrypt = aead_null_givdecrypt;
191    }
192    crt->base = __crypto_aead_cast(tfm);
193    crt->ivsize = alg->ivsize;
194    crt->authsize = alg->maxauthsize;
195
196    return 0;
197}
198
199#ifdef CONFIG_NET
200static int crypto_nivaead_report(struct sk_buff *skb, struct crypto_alg *alg)
201{
202    struct crypto_report_aead raead;
203    struct aead_alg *aead = &alg->cra_aead;
204
205    strncpy(raead.type, "nivaead", sizeof(raead.type));
206    strncpy(raead.geniv, aead->geniv, sizeof(raead.geniv));
207
208    raead.blocksize = alg->cra_blocksize;
209    raead.maxauthsize = aead->maxauthsize;
210    raead.ivsize = aead->ivsize;
211
212    if (nla_put(skb, CRYPTOCFGA_REPORT_AEAD,
213            sizeof(struct crypto_report_aead), &raead))
214        goto nla_put_failure;
215    return 0;
216
217nla_put_failure:
218    return -EMSGSIZE;
219}
220#else
221static int crypto_nivaead_report(struct sk_buff *skb, struct crypto_alg *alg)
222{
223    return -ENOSYS;
224}
225#endif
226
227
228static void crypto_nivaead_show(struct seq_file *m, struct crypto_alg *alg)
229    __attribute__ ((unused));
230static void crypto_nivaead_show(struct seq_file *m, struct crypto_alg *alg)
231{
232    struct aead_alg *aead = &alg->cra_aead;
233
234    seq_printf(m, "type : nivaead\n");
235    seq_printf(m, "async : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
236                         "yes" : "no");
237    seq_printf(m, "blocksize : %u\n", alg->cra_blocksize);
238    seq_printf(m, "ivsize : %u\n", aead->ivsize);
239    seq_printf(m, "maxauthsize : %u\n", aead->maxauthsize);
240    seq_printf(m, "geniv : %s\n", aead->geniv);
241}
242
243const struct crypto_type crypto_nivaead_type = {
244    .ctxsize = crypto_aead_ctxsize,
245    .init = crypto_init_nivaead_ops,
246#ifdef CONFIG_PROC_FS
247    .show = crypto_nivaead_show,
248#endif
249    .report = crypto_nivaead_report,
250};
251EXPORT_SYMBOL_GPL(crypto_nivaead_type);
252
253static int crypto_grab_nivaead(struct crypto_aead_spawn *spawn,
254                   const char *name, u32 type, u32 mask)
255{
256    struct crypto_alg *alg;
257    int err;
258
259    type &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
260    type |= CRYPTO_ALG_TYPE_AEAD;
261    mask |= CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV;
262
263    alg = crypto_alg_mod_lookup(name, type, mask);
264    if (IS_ERR(alg))
265        return PTR_ERR(alg);
266
267    err = crypto_init_spawn(&spawn->base, alg, spawn->base.inst, mask);
268    crypto_mod_put(alg);
269    return err;
270}
271
272struct crypto_instance *aead_geniv_alloc(struct crypto_template *tmpl,
273                     struct rtattr **tb, u32 type,
274                     u32 mask)
275{
276    const char *name;
277    struct crypto_aead_spawn *spawn;
278    struct crypto_attr_type *algt;
279    struct crypto_instance *inst;
280    struct crypto_alg *alg;
281    int err;
282
283    algt = crypto_get_attr_type(tb);
284    if (IS_ERR(algt))
285        return ERR_CAST(algt);
286
287    if ((algt->type ^ (CRYPTO_ALG_TYPE_AEAD | CRYPTO_ALG_GENIV)) &
288        algt->mask)
289        return ERR_PTR(-EINVAL);
290
291    name = crypto_attr_alg_name(tb[1]);
292    if (IS_ERR(name))
293        return ERR_CAST(name);
294
295    inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
296    if (!inst)
297        return ERR_PTR(-ENOMEM);
298
299    spawn = crypto_instance_ctx(inst);
300
301    /* Ignore async algorithms if necessary. */
302    mask |= crypto_requires_sync(algt->type, algt->mask);
303
304    crypto_set_aead_spawn(spawn, inst);
305    err = crypto_grab_nivaead(spawn, name, type, mask);
306    if (err)
307        goto err_free_inst;
308
309    alg = crypto_aead_spawn_alg(spawn);
310
311    err = -EINVAL;
312    if (!alg->cra_aead.ivsize)
313        goto err_drop_alg;
314
315    /*
316     * This is only true if we're constructing an algorithm with its
317     * default IV generator. For the default generator we elide the
318     * template name and double-check the IV generator.
319     */
320    if (algt->mask & CRYPTO_ALG_GENIV) {
321        if (strcmp(tmpl->name, alg->cra_aead.geniv))
322            goto err_drop_alg;
323
324        memcpy(inst->alg.cra_name, alg->cra_name, CRYPTO_MAX_ALG_NAME);
325        memcpy(inst->alg.cra_driver_name, alg->cra_driver_name,
326               CRYPTO_MAX_ALG_NAME);
327    } else {
328        err = -ENAMETOOLONG;
329        if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME,
330                 "%s(%s)", tmpl->name, alg->cra_name) >=
331            CRYPTO_MAX_ALG_NAME)
332            goto err_drop_alg;
333        if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
334                 "%s(%s)", tmpl->name, alg->cra_driver_name) >=
335            CRYPTO_MAX_ALG_NAME)
336            goto err_drop_alg;
337    }
338
339    inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD | CRYPTO_ALG_GENIV;
340    inst->alg.cra_flags |= alg->cra_flags & CRYPTO_ALG_ASYNC;
341    inst->alg.cra_priority = alg->cra_priority;
342    inst->alg.cra_blocksize = alg->cra_blocksize;
343    inst->alg.cra_alignmask = alg->cra_alignmask;
344    inst->alg.cra_type = &crypto_aead_type;
345
346    inst->alg.cra_aead.ivsize = alg->cra_aead.ivsize;
347    inst->alg.cra_aead.maxauthsize = alg->cra_aead.maxauthsize;
348    inst->alg.cra_aead.geniv = alg->cra_aead.geniv;
349
350    inst->alg.cra_aead.setkey = alg->cra_aead.setkey;
351    inst->alg.cra_aead.setauthsize = alg->cra_aead.setauthsize;
352    inst->alg.cra_aead.encrypt = alg->cra_aead.encrypt;
353    inst->alg.cra_aead.decrypt = alg->cra_aead.decrypt;
354
355out:
356    return inst;
357
358err_drop_alg:
359    crypto_drop_aead(spawn);
360err_free_inst:
361    kfree(inst);
362    inst = ERR_PTR(err);
363    goto out;
364}
365EXPORT_SYMBOL_GPL(aead_geniv_alloc);
366
367void aead_geniv_free(struct crypto_instance *inst)
368{
369    crypto_drop_aead(crypto_instance_ctx(inst));
370    kfree(inst);
371}
372EXPORT_SYMBOL_GPL(aead_geniv_free);
373
374int aead_geniv_init(struct crypto_tfm *tfm)
375{
376    struct crypto_instance *inst = (void *)tfm->__crt_alg;
377    struct crypto_aead *aead;
378
379    aead = crypto_spawn_aead(crypto_instance_ctx(inst));
380    if (IS_ERR(aead))
381        return PTR_ERR(aead);
382
383    tfm->crt_aead.base = aead;
384    tfm->crt_aead.reqsize += crypto_aead_reqsize(aead);
385
386    return 0;
387}
388EXPORT_SYMBOL_GPL(aead_geniv_init);
389
390void aead_geniv_exit(struct crypto_tfm *tfm)
391{
392    crypto_free_aead(tfm->crt_aead.base);
393}
394EXPORT_SYMBOL_GPL(aead_geniv_exit);
395
396static int crypto_nivaead_default(struct crypto_alg *alg, u32 type, u32 mask)
397{
398    struct rtattr *tb[3];
399    struct {
400        struct rtattr attr;
401        struct crypto_attr_type data;
402    } ptype;
403    struct {
404        struct rtattr attr;
405        struct crypto_attr_alg data;
406    } palg;
407    struct crypto_template *tmpl;
408    struct crypto_instance *inst;
409    struct crypto_alg *larval;
410    const char *geniv;
411    int err;
412
413    larval = crypto_larval_lookup(alg->cra_driver_name,
414                      CRYPTO_ALG_TYPE_AEAD | CRYPTO_ALG_GENIV,
415                      CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
416    err = PTR_ERR(larval);
417    if (IS_ERR(larval))
418        goto out;
419
420    err = -EAGAIN;
421    if (!crypto_is_larval(larval))
422        goto drop_larval;
423
424    ptype.attr.rta_len = sizeof(ptype);
425    ptype.attr.rta_type = CRYPTOA_TYPE;
426    ptype.data.type = type | CRYPTO_ALG_GENIV;
427    /* GENIV tells the template that we're making a default geniv. */
428    ptype.data.mask = mask | CRYPTO_ALG_GENIV;
429    tb[0] = &ptype.attr;
430
431    palg.attr.rta_len = sizeof(palg);
432    palg.attr.rta_type = CRYPTOA_ALG;
433    /* Must use the exact name to locate ourselves. */
434    memcpy(palg.data.name, alg->cra_driver_name, CRYPTO_MAX_ALG_NAME);
435    tb[1] = &palg.attr;
436
437    tb[2] = NULL;
438
439    geniv = alg->cra_aead.geniv;
440
441    tmpl = crypto_lookup_template(geniv);
442    err = -ENOENT;
443    if (!tmpl)
444        goto kill_larval;
445
446    inst = tmpl->alloc(tb);
447    err = PTR_ERR(inst);
448    if (IS_ERR(inst))
449        goto put_tmpl;
450
451    if ((err = crypto_register_instance(tmpl, inst))) {
452        tmpl->free(inst);
453        goto put_tmpl;
454    }
455
456    /* Redo the lookup to use the instance we just registered. */
457    err = -EAGAIN;
458
459put_tmpl:
460    crypto_tmpl_put(tmpl);
461kill_larval:
462    crypto_larval_kill(larval);
463drop_larval:
464    crypto_mod_put(larval);
465out:
466    crypto_mod_put(alg);
467    return err;
468}
469
470struct crypto_alg *crypto_lookup_aead(const char *name, u32 type, u32 mask)
471{
472    struct crypto_alg *alg;
473
474    alg = crypto_alg_mod_lookup(name, type, mask);
475    if (IS_ERR(alg))
476        return alg;
477
478    if (alg->cra_type == &crypto_aead_type)
479        return alg;
480
481    if (!alg->cra_aead.ivsize)
482        return alg;
483
484    crypto_mod_put(alg);
485    alg = crypto_alg_mod_lookup(name, type | CRYPTO_ALG_TESTED,
486                    mask & ~CRYPTO_ALG_TESTED);
487    if (IS_ERR(alg))
488        return alg;
489
490    if (alg->cra_type == &crypto_aead_type) {
491        if ((alg->cra_flags ^ type ^ ~mask) & CRYPTO_ALG_TESTED) {
492            crypto_mod_put(alg);
493            alg = ERR_PTR(-ENOENT);
494        }
495        return alg;
496    }
497
498    BUG_ON(!alg->cra_aead.ivsize);
499
500    return ERR_PTR(crypto_nivaead_default(alg, type, mask));
501}
502EXPORT_SYMBOL_GPL(crypto_lookup_aead);
503
504int crypto_grab_aead(struct crypto_aead_spawn *spawn, const char *name,
505             u32 type, u32 mask)
506{
507    struct crypto_alg *alg;
508    int err;
509
510    type &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
511    type |= CRYPTO_ALG_TYPE_AEAD;
512    mask &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
513    mask |= CRYPTO_ALG_TYPE_MASK;
514
515    alg = crypto_lookup_aead(name, type, mask);
516    if (IS_ERR(alg))
517        return PTR_ERR(alg);
518
519    err = crypto_init_spawn(&spawn->base, alg, spawn->base.inst, mask);
520    crypto_mod_put(alg);
521    return err;
522}
523EXPORT_SYMBOL_GPL(crypto_grab_aead);
524
525struct crypto_aead *crypto_alloc_aead(const char *alg_name, u32 type, u32 mask)
526{
527    struct crypto_tfm *tfm;
528    int err;
529
530    type &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
531    type |= CRYPTO_ALG_TYPE_AEAD;
532    mask &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
533    mask |= CRYPTO_ALG_TYPE_MASK;
534
535    for (;;) {
536        struct crypto_alg *alg;
537
538        alg = crypto_lookup_aead(alg_name, type, mask);
539        if (IS_ERR(alg)) {
540            err = PTR_ERR(alg);
541            goto err;
542        }
543
544        tfm = __crypto_alloc_tfm(alg, type, mask);
545        if (!IS_ERR(tfm))
546            return __crypto_aead_cast(tfm);
547
548        crypto_mod_put(alg);
549        err = PTR_ERR(tfm);
550
551err:
552        if (err != -EAGAIN)
553            break;
554        if (signal_pending(current)) {
555            err = -EINTR;
556            break;
557        }
558    }
559
560    return ERR_PTR(err);
561}
562EXPORT_SYMBOL_GPL(crypto_alloc_aead);
563
564MODULE_LICENSE("GPL");
565MODULE_DESCRIPTION("Authenticated Encryption with Associated Data (AEAD)");
566

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