Root/crypto/authenc.c

1/*
2 * Authenc: Simple AEAD wrapper for IPsec
3 *
4 * Copyright (c) 2007 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/aead.h>
14#include <crypto/internal/hash.h>
15#include <crypto/internal/skcipher.h>
16#include <crypto/authenc.h>
17#include <crypto/scatterwalk.h>
18#include <linux/err.h>
19#include <linux/init.h>
20#include <linux/kernel.h>
21#include <linux/module.h>
22#include <linux/rtnetlink.h>
23#include <linux/slab.h>
24#include <linux/spinlock.h>
25
26typedef u8 *(*authenc_ahash_t)(struct aead_request *req, unsigned int flags);
27
28struct authenc_instance_ctx {
29    struct crypto_ahash_spawn auth;
30    struct crypto_skcipher_spawn enc;
31};
32
33struct crypto_authenc_ctx {
34    unsigned int reqoff;
35    struct crypto_ahash *auth;
36    struct crypto_ablkcipher *enc;
37};
38
39struct authenc_request_ctx {
40    unsigned int cryptlen;
41    struct scatterlist *sg;
42    struct scatterlist asg[2];
43    struct scatterlist cipher[2];
44    crypto_completion_t complete;
45    crypto_completion_t update_complete;
46    char tail[];
47};
48
49static void authenc_request_complete(struct aead_request *req, int err)
50{
51    if (err != -EINPROGRESS)
52        aead_request_complete(req, err);
53}
54
55static int crypto_authenc_setkey(struct crypto_aead *authenc, const u8 *key,
56                 unsigned int keylen)
57{
58    unsigned int authkeylen;
59    unsigned int enckeylen;
60    struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
61    struct crypto_ahash *auth = ctx->auth;
62    struct crypto_ablkcipher *enc = ctx->enc;
63    struct rtattr *rta = (void *)key;
64    struct crypto_authenc_key_param *param;
65    int err = -EINVAL;
66
67    if (!RTA_OK(rta, keylen))
68        goto badkey;
69    if (rta->rta_type != CRYPTO_AUTHENC_KEYA_PARAM)
70        goto badkey;
71    if (RTA_PAYLOAD(rta) < sizeof(*param))
72        goto badkey;
73
74    param = RTA_DATA(rta);
75    enckeylen = be32_to_cpu(param->enckeylen);
76
77    key += RTA_ALIGN(rta->rta_len);
78    keylen -= RTA_ALIGN(rta->rta_len);
79
80    if (keylen < enckeylen)
81        goto badkey;
82
83    authkeylen = keylen - enckeylen;
84
85    crypto_ahash_clear_flags(auth, CRYPTO_TFM_REQ_MASK);
86    crypto_ahash_set_flags(auth, crypto_aead_get_flags(authenc) &
87                    CRYPTO_TFM_REQ_MASK);
88    err = crypto_ahash_setkey(auth, key, authkeylen);
89    crypto_aead_set_flags(authenc, crypto_ahash_get_flags(auth) &
90                       CRYPTO_TFM_RES_MASK);
91
92    if (err)
93        goto out;
94
95    crypto_ablkcipher_clear_flags(enc, CRYPTO_TFM_REQ_MASK);
96    crypto_ablkcipher_set_flags(enc, crypto_aead_get_flags(authenc) &
97                     CRYPTO_TFM_REQ_MASK);
98    err = crypto_ablkcipher_setkey(enc, key + authkeylen, enckeylen);
99    crypto_aead_set_flags(authenc, crypto_ablkcipher_get_flags(enc) &
100                       CRYPTO_TFM_RES_MASK);
101
102out:
103    return err;
104
105badkey:
106    crypto_aead_set_flags(authenc, CRYPTO_TFM_RES_BAD_KEY_LEN);
107    goto out;
108}
109
110static void authenc_chain(struct scatterlist *head, struct scatterlist *sg,
111              int chain)
112{
113    if (chain) {
114        head->length += sg->length;
115        sg = scatterwalk_sg_next(sg);
116    }
117
118    if (sg)
119        scatterwalk_sg_chain(head, 2, sg);
120    else
121        sg_mark_end(head);
122}
123
124static void authenc_geniv_ahash_update_done(struct crypto_async_request *areq,
125                        int err)
126{
127    struct aead_request *req = areq->data;
128    struct crypto_aead *authenc = crypto_aead_reqtfm(req);
129    struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
130    struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
131    struct ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
132
133    if (err)
134        goto out;
135
136    ahash_request_set_crypt(ahreq, areq_ctx->sg, ahreq->result,
137                areq_ctx->cryptlen);
138    ahash_request_set_callback(ahreq, aead_request_flags(req) &
139                      CRYPTO_TFM_REQ_MAY_SLEEP,
140                   areq_ctx->complete, req);
141
142    err = crypto_ahash_finup(ahreq);
143    if (err)
144        goto out;
145
146    scatterwalk_map_and_copy(ahreq->result, areq_ctx->sg,
147                 areq_ctx->cryptlen,
148                 crypto_aead_authsize(authenc), 1);
149
150out:
151    authenc_request_complete(req, err);
152}
153
154static void authenc_geniv_ahash_done(struct crypto_async_request *areq, int err)
155{
156    struct aead_request *req = areq->data;
157    struct crypto_aead *authenc = crypto_aead_reqtfm(req);
158    struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
159    struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
160    struct ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
161
162    if (err)
163        goto out;
164
165    scatterwalk_map_and_copy(ahreq->result, areq_ctx->sg,
166                 areq_ctx->cryptlen,
167                 crypto_aead_authsize(authenc), 1);
168
169out:
170    aead_request_complete(req, err);
171}
172
173static void authenc_verify_ahash_update_done(struct crypto_async_request *areq,
174                         int err)
175{
176    u8 *ihash;
177    unsigned int authsize;
178    struct ablkcipher_request *abreq;
179    struct aead_request *req = areq->data;
180    struct crypto_aead *authenc = crypto_aead_reqtfm(req);
181    struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
182    struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
183    struct ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
184    unsigned int cryptlen = req->cryptlen;
185
186    if (err)
187        goto out;
188
189    ahash_request_set_crypt(ahreq, areq_ctx->sg, ahreq->result,
190                areq_ctx->cryptlen);
191    ahash_request_set_callback(ahreq, aead_request_flags(req) &
192                      CRYPTO_TFM_REQ_MAY_SLEEP,
193                   areq_ctx->complete, req);
194
195    err = crypto_ahash_finup(ahreq);
196    if (err)
197        goto out;
198
199    authsize = crypto_aead_authsize(authenc);
200    cryptlen -= authsize;
201    ihash = ahreq->result + authsize;
202    scatterwalk_map_and_copy(ihash, areq_ctx->sg, areq_ctx->cryptlen,
203                 authsize, 0);
204
205    err = memcmp(ihash, ahreq->result, authsize) ? -EBADMSG : 0;
206    if (err)
207        goto out;
208
209    abreq = aead_request_ctx(req);
210    ablkcipher_request_set_tfm(abreq, ctx->enc);
211    ablkcipher_request_set_callback(abreq, aead_request_flags(req),
212                    req->base.complete, req->base.data);
213    ablkcipher_request_set_crypt(abreq, req->src, req->dst,
214                     cryptlen, req->iv);
215
216    err = crypto_ablkcipher_decrypt(abreq);
217
218out:
219    authenc_request_complete(req, err);
220}
221
222static void authenc_verify_ahash_done(struct crypto_async_request *areq,
223                      int err)
224{
225    u8 *ihash;
226    unsigned int authsize;
227    struct ablkcipher_request *abreq;
228    struct aead_request *req = areq->data;
229    struct crypto_aead *authenc = crypto_aead_reqtfm(req);
230    struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
231    struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
232    struct ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
233    unsigned int cryptlen = req->cryptlen;
234
235    if (err)
236        goto out;
237
238    authsize = crypto_aead_authsize(authenc);
239    cryptlen -= authsize;
240    ihash = ahreq->result + authsize;
241    scatterwalk_map_and_copy(ihash, areq_ctx->sg, areq_ctx->cryptlen,
242                 authsize, 0);
243
244    err = memcmp(ihash, ahreq->result, authsize) ? -EBADMSG : 0;
245    if (err)
246        goto out;
247
248    abreq = aead_request_ctx(req);
249    ablkcipher_request_set_tfm(abreq, ctx->enc);
250    ablkcipher_request_set_callback(abreq, aead_request_flags(req),
251                    req->base.complete, req->base.data);
252    ablkcipher_request_set_crypt(abreq, req->src, req->dst,
253                     cryptlen, req->iv);
254
255    err = crypto_ablkcipher_decrypt(abreq);
256
257out:
258    authenc_request_complete(req, err);
259}
260
261static u8 *crypto_authenc_ahash_fb(struct aead_request *req, unsigned int flags)
262{
263    struct crypto_aead *authenc = crypto_aead_reqtfm(req);
264    struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
265    struct crypto_ahash *auth = ctx->auth;
266    struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
267    struct ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
268    u8 *hash = areq_ctx->tail;
269    int err;
270
271    hash = (u8 *)ALIGN((unsigned long)hash + crypto_ahash_alignmask(auth),
272                crypto_ahash_alignmask(auth) + 1);
273
274    ahash_request_set_tfm(ahreq, auth);
275
276    err = crypto_ahash_init(ahreq);
277    if (err)
278        return ERR_PTR(err);
279
280    ahash_request_set_crypt(ahreq, req->assoc, hash, req->assoclen);
281    ahash_request_set_callback(ahreq, aead_request_flags(req) & flags,
282                   areq_ctx->update_complete, req);
283
284    err = crypto_ahash_update(ahreq);
285    if (err)
286        return ERR_PTR(err);
287
288    ahash_request_set_crypt(ahreq, areq_ctx->sg, hash,
289                areq_ctx->cryptlen);
290    ahash_request_set_callback(ahreq, aead_request_flags(req) & flags,
291                   areq_ctx->complete, req);
292
293    err = crypto_ahash_finup(ahreq);
294    if (err)
295        return ERR_PTR(err);
296
297    return hash;
298}
299
300static u8 *crypto_authenc_ahash(struct aead_request *req, unsigned int flags)
301{
302    struct crypto_aead *authenc = crypto_aead_reqtfm(req);
303    struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
304    struct crypto_ahash *auth = ctx->auth;
305    struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
306    struct ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
307    u8 *hash = areq_ctx->tail;
308    int err;
309
310    hash = (u8 *)ALIGN((unsigned long)hash + crypto_ahash_alignmask(auth),
311               crypto_ahash_alignmask(auth) + 1);
312
313    ahash_request_set_tfm(ahreq, auth);
314    ahash_request_set_crypt(ahreq, areq_ctx->sg, hash,
315                areq_ctx->cryptlen);
316    ahash_request_set_callback(ahreq, aead_request_flags(req) & flags,
317                   areq_ctx->complete, req);
318
319    err = crypto_ahash_digest(ahreq);
320    if (err)
321        return ERR_PTR(err);
322
323    return hash;
324}
325
326static int crypto_authenc_genicv(struct aead_request *req, u8 *iv,
327                 unsigned int flags)
328{
329    struct crypto_aead *authenc = crypto_aead_reqtfm(req);
330    struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
331    struct scatterlist *dst = req->dst;
332    struct scatterlist *assoc = req->assoc;
333    struct scatterlist *cipher = areq_ctx->cipher;
334    struct scatterlist *asg = areq_ctx->asg;
335    unsigned int ivsize = crypto_aead_ivsize(authenc);
336    unsigned int cryptlen = req->cryptlen;
337    authenc_ahash_t authenc_ahash_fn = crypto_authenc_ahash_fb;
338    struct page *dstp;
339    u8 *vdst;
340    u8 *hash;
341
342    dstp = sg_page(dst);
343    vdst = PageHighMem(dstp) ? NULL : page_address(dstp) + dst->offset;
344
345    if (ivsize) {
346        sg_init_table(cipher, 2);
347        sg_set_buf(cipher, iv, ivsize);
348        authenc_chain(cipher, dst, vdst == iv + ivsize);
349        dst = cipher;
350        cryptlen += ivsize;
351    }
352
353    if (sg_is_last(assoc)) {
354        authenc_ahash_fn = crypto_authenc_ahash;
355        sg_init_table(asg, 2);
356        sg_set_page(asg, sg_page(assoc), assoc->length, assoc->offset);
357        authenc_chain(asg, dst, 0);
358        dst = asg;
359        cryptlen += req->assoclen;
360    }
361
362    areq_ctx->cryptlen = cryptlen;
363    areq_ctx->sg = dst;
364
365    areq_ctx->complete = authenc_geniv_ahash_done;
366    areq_ctx->update_complete = authenc_geniv_ahash_update_done;
367
368    hash = authenc_ahash_fn(req, flags);
369    if (IS_ERR(hash))
370        return PTR_ERR(hash);
371
372    scatterwalk_map_and_copy(hash, dst, cryptlen,
373                 crypto_aead_authsize(authenc), 1);
374    return 0;
375}
376
377static void crypto_authenc_encrypt_done(struct crypto_async_request *req,
378                    int err)
379{
380    struct aead_request *areq = req->data;
381
382    if (!err) {
383        struct crypto_aead *authenc = crypto_aead_reqtfm(areq);
384        struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
385        struct ablkcipher_request *abreq = aead_request_ctx(areq);
386        u8 *iv = (u8 *)(abreq + 1) +
387             crypto_ablkcipher_reqsize(ctx->enc);
388
389        err = crypto_authenc_genicv(areq, iv, 0);
390    }
391
392    authenc_request_complete(areq, err);
393}
394
395static int crypto_authenc_encrypt(struct aead_request *req)
396{
397    struct crypto_aead *authenc = crypto_aead_reqtfm(req);
398    struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
399    struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
400    struct crypto_ablkcipher *enc = ctx->enc;
401    struct scatterlist *dst = req->dst;
402    unsigned int cryptlen = req->cryptlen;
403    struct ablkcipher_request *abreq = (void *)(areq_ctx->tail
404                            + ctx->reqoff);
405    u8 *iv = (u8 *)abreq - crypto_ablkcipher_ivsize(enc);
406    int err;
407
408    ablkcipher_request_set_tfm(abreq, enc);
409    ablkcipher_request_set_callback(abreq, aead_request_flags(req),
410                    crypto_authenc_encrypt_done, req);
411    ablkcipher_request_set_crypt(abreq, req->src, dst, cryptlen, req->iv);
412
413    memcpy(iv, req->iv, crypto_aead_ivsize(authenc));
414
415    err = crypto_ablkcipher_encrypt(abreq);
416    if (err)
417        return err;
418
419    return crypto_authenc_genicv(req, iv, CRYPTO_TFM_REQ_MAY_SLEEP);
420}
421
422static void crypto_authenc_givencrypt_done(struct crypto_async_request *req,
423                       int err)
424{
425    struct aead_request *areq = req->data;
426
427    if (!err) {
428        struct skcipher_givcrypt_request *greq = aead_request_ctx(areq);
429
430        err = crypto_authenc_genicv(areq, greq->giv, 0);
431    }
432
433    authenc_request_complete(areq, err);
434}
435
436static int crypto_authenc_givencrypt(struct aead_givcrypt_request *req)
437{
438    struct crypto_aead *authenc = aead_givcrypt_reqtfm(req);
439    struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
440    struct aead_request *areq = &req->areq;
441    struct skcipher_givcrypt_request *greq = aead_request_ctx(areq);
442    u8 *iv = req->giv;
443    int err;
444
445    skcipher_givcrypt_set_tfm(greq, ctx->enc);
446    skcipher_givcrypt_set_callback(greq, aead_request_flags(areq),
447                       crypto_authenc_givencrypt_done, areq);
448    skcipher_givcrypt_set_crypt(greq, areq->src, areq->dst, areq->cryptlen,
449                    areq->iv);
450    skcipher_givcrypt_set_giv(greq, iv, req->seq);
451
452    err = crypto_skcipher_givencrypt(greq);
453    if (err)
454        return err;
455
456    return crypto_authenc_genicv(areq, iv, CRYPTO_TFM_REQ_MAY_SLEEP);
457}
458
459static int crypto_authenc_verify(struct aead_request *req,
460                 authenc_ahash_t authenc_ahash_fn)
461{
462    struct crypto_aead *authenc = crypto_aead_reqtfm(req);
463    struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
464    u8 *ohash;
465    u8 *ihash;
466    unsigned int authsize;
467
468    areq_ctx->complete = authenc_verify_ahash_done;
469    areq_ctx->update_complete = authenc_verify_ahash_update_done;
470
471    ohash = authenc_ahash_fn(req, CRYPTO_TFM_REQ_MAY_SLEEP);
472    if (IS_ERR(ohash))
473        return PTR_ERR(ohash);
474
475    authsize = crypto_aead_authsize(authenc);
476    ihash = ohash + authsize;
477    scatterwalk_map_and_copy(ihash, areq_ctx->sg, areq_ctx->cryptlen,
478                 authsize, 0);
479    return memcmp(ihash, ohash, authsize) ? -EBADMSG : 0;
480}
481
482static int crypto_authenc_iverify(struct aead_request *req, u8 *iv,
483                  unsigned int cryptlen)
484{
485    struct crypto_aead *authenc = crypto_aead_reqtfm(req);
486    struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
487    struct scatterlist *src = req->src;
488    struct scatterlist *assoc = req->assoc;
489    struct scatterlist *cipher = areq_ctx->cipher;
490    struct scatterlist *asg = areq_ctx->asg;
491    unsigned int ivsize = crypto_aead_ivsize(authenc);
492    authenc_ahash_t authenc_ahash_fn = crypto_authenc_ahash_fb;
493    struct page *srcp;
494    u8 *vsrc;
495
496    srcp = sg_page(src);
497    vsrc = PageHighMem(srcp) ? NULL : page_address(srcp) + src->offset;
498
499    if (ivsize) {
500        sg_init_table(cipher, 2);
501        sg_set_buf(cipher, iv, ivsize);
502        authenc_chain(cipher, src, vsrc == iv + ivsize);
503        src = cipher;
504        cryptlen += ivsize;
505    }
506
507    if (sg_is_last(assoc)) {
508        authenc_ahash_fn = crypto_authenc_ahash;
509        sg_init_table(asg, 2);
510        sg_set_page(asg, sg_page(assoc), assoc->length, assoc->offset);
511        authenc_chain(asg, src, 0);
512        src = asg;
513        cryptlen += req->assoclen;
514    }
515
516    areq_ctx->cryptlen = cryptlen;
517    areq_ctx->sg = src;
518
519    return crypto_authenc_verify(req, authenc_ahash_fn);
520}
521
522static int crypto_authenc_decrypt(struct aead_request *req)
523{
524    struct crypto_aead *authenc = crypto_aead_reqtfm(req);
525    struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
526    struct ablkcipher_request *abreq = aead_request_ctx(req);
527    unsigned int cryptlen = req->cryptlen;
528    unsigned int authsize = crypto_aead_authsize(authenc);
529    u8 *iv = req->iv;
530    int err;
531
532    if (cryptlen < authsize)
533        return -EINVAL;
534    cryptlen -= authsize;
535
536    err = crypto_authenc_iverify(req, iv, cryptlen);
537    if (err)
538        return err;
539
540    ablkcipher_request_set_tfm(abreq, ctx->enc);
541    ablkcipher_request_set_callback(abreq, aead_request_flags(req),
542                    req->base.complete, req->base.data);
543    ablkcipher_request_set_crypt(abreq, req->src, req->dst, cryptlen, iv);
544
545    return crypto_ablkcipher_decrypt(abreq);
546}
547
548static int crypto_authenc_init_tfm(struct crypto_tfm *tfm)
549{
550    struct crypto_instance *inst = crypto_tfm_alg_instance(tfm);
551    struct authenc_instance_ctx *ictx = crypto_instance_ctx(inst);
552    struct crypto_authenc_ctx *ctx = crypto_tfm_ctx(tfm);
553    struct crypto_ahash *auth;
554    struct crypto_ablkcipher *enc;
555    int err;
556
557    auth = crypto_spawn_ahash(&ictx->auth);
558    if (IS_ERR(auth))
559        return PTR_ERR(auth);
560
561    enc = crypto_spawn_skcipher(&ictx->enc);
562    err = PTR_ERR(enc);
563    if (IS_ERR(enc))
564        goto err_free_ahash;
565
566    ctx->auth = auth;
567    ctx->enc = enc;
568
569    ctx->reqoff = ALIGN(2 * crypto_ahash_digestsize(auth) +
570                crypto_ahash_alignmask(auth),
571                crypto_ahash_alignmask(auth) + 1) +
572              crypto_ablkcipher_ivsize(enc);
573
574    tfm->crt_aead.reqsize = sizeof(struct authenc_request_ctx) +
575                ctx->reqoff +
576                max_t(unsigned int,
577                crypto_ahash_reqsize(auth) +
578                sizeof(struct ahash_request),
579                sizeof(struct skcipher_givcrypt_request) +
580                crypto_ablkcipher_reqsize(enc));
581
582    return 0;
583
584err_free_ahash:
585    crypto_free_ahash(auth);
586    return err;
587}
588
589static void crypto_authenc_exit_tfm(struct crypto_tfm *tfm)
590{
591    struct crypto_authenc_ctx *ctx = crypto_tfm_ctx(tfm);
592
593    crypto_free_ahash(ctx->auth);
594    crypto_free_ablkcipher(ctx->enc);
595}
596
597static struct crypto_instance *crypto_authenc_alloc(struct rtattr **tb)
598{
599    struct crypto_attr_type *algt;
600    struct crypto_instance *inst;
601    struct hash_alg_common *auth;
602    struct crypto_alg *auth_base;
603    struct crypto_alg *enc;
604    struct authenc_instance_ctx *ctx;
605    const char *enc_name;
606    int err;
607
608    algt = crypto_get_attr_type(tb);
609    err = PTR_ERR(algt);
610    if (IS_ERR(algt))
611        return ERR_PTR(err);
612
613    if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
614        return ERR_PTR(-EINVAL);
615
616    auth = ahash_attr_alg(tb[1], CRYPTO_ALG_TYPE_HASH,
617                   CRYPTO_ALG_TYPE_AHASH_MASK);
618    if (IS_ERR(auth))
619        return ERR_CAST(auth);
620
621    auth_base = &auth->base;
622
623    enc_name = crypto_attr_alg_name(tb[2]);
624    err = PTR_ERR(enc_name);
625    if (IS_ERR(enc_name))
626        goto out_put_auth;
627
628    inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
629    err = -ENOMEM;
630    if (!inst)
631        goto out_put_auth;
632
633    ctx = crypto_instance_ctx(inst);
634
635    err = crypto_init_ahash_spawn(&ctx->auth, auth, inst);
636    if (err)
637        goto err_free_inst;
638
639    crypto_set_skcipher_spawn(&ctx->enc, inst);
640    err = crypto_grab_skcipher(&ctx->enc, enc_name, 0,
641                   crypto_requires_sync(algt->type,
642                            algt->mask));
643    if (err)
644        goto err_drop_auth;
645
646    enc = crypto_skcipher_spawn_alg(&ctx->enc);
647
648    err = -ENAMETOOLONG;
649    if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME,
650             "authenc(%s,%s)", auth_base->cra_name, enc->cra_name) >=
651        CRYPTO_MAX_ALG_NAME)
652        goto err_drop_enc;
653
654    if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
655             "authenc(%s,%s)", auth_base->cra_driver_name,
656             enc->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
657        goto err_drop_enc;
658
659    inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD;
660    inst->alg.cra_flags |= enc->cra_flags & CRYPTO_ALG_ASYNC;
661    inst->alg.cra_priority = enc->cra_priority *
662                 10 + auth_base->cra_priority;
663    inst->alg.cra_blocksize = enc->cra_blocksize;
664    inst->alg.cra_alignmask = auth_base->cra_alignmask | enc->cra_alignmask;
665    inst->alg.cra_type = &crypto_aead_type;
666
667    inst->alg.cra_aead.ivsize = enc->cra_ablkcipher.ivsize;
668    inst->alg.cra_aead.maxauthsize = auth->digestsize;
669
670    inst->alg.cra_ctxsize = sizeof(struct crypto_authenc_ctx);
671
672    inst->alg.cra_init = crypto_authenc_init_tfm;
673    inst->alg.cra_exit = crypto_authenc_exit_tfm;
674
675    inst->alg.cra_aead.setkey = crypto_authenc_setkey;
676    inst->alg.cra_aead.encrypt = crypto_authenc_encrypt;
677    inst->alg.cra_aead.decrypt = crypto_authenc_decrypt;
678    inst->alg.cra_aead.givencrypt = crypto_authenc_givencrypt;
679
680out:
681    crypto_mod_put(auth_base);
682    return inst;
683
684err_drop_enc:
685    crypto_drop_skcipher(&ctx->enc);
686err_drop_auth:
687    crypto_drop_ahash(&ctx->auth);
688err_free_inst:
689    kfree(inst);
690out_put_auth:
691    inst = ERR_PTR(err);
692    goto out;
693}
694
695static void crypto_authenc_free(struct crypto_instance *inst)
696{
697    struct authenc_instance_ctx *ctx = crypto_instance_ctx(inst);
698
699    crypto_drop_skcipher(&ctx->enc);
700    crypto_drop_ahash(&ctx->auth);
701    kfree(inst);
702}
703
704static struct crypto_template crypto_authenc_tmpl = {
705    .name = "authenc",
706    .alloc = crypto_authenc_alloc,
707    .free = crypto_authenc_free,
708    .module = THIS_MODULE,
709};
710
711static int __init crypto_authenc_module_init(void)
712{
713    return crypto_register_template(&crypto_authenc_tmpl);
714}
715
716static void __exit crypto_authenc_module_exit(void)
717{
718    crypto_unregister_template(&crypto_authenc_tmpl);
719}
720
721module_init(crypto_authenc_module_init);
722module_exit(crypto_authenc_module_exit);
723
724MODULE_LICENSE("GPL");
725MODULE_DESCRIPTION("Simple AEAD wrapper for IPsec");
726

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