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TOMOYO Linux Cross Reference
Linux/crypto/ccm.c

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  1 // SPDX-License-Identifier: GPL-2.0-or-later
  2 /*
  3  * CCM: Counter with CBC-MAC
  4  *
  5  * (C) Copyright IBM Corp. 2007 - Joy Latten <latten@us.ibm.com>
  6  */
  7 
  8 #include <crypto/internal/aead.h>
  9 #include <crypto/internal/cipher.h>
 10 #include <crypto/internal/hash.h>
 11 #include <crypto/internal/skcipher.h>
 12 #include <crypto/scatterwalk.h>
 13 #include <linux/err.h>
 14 #include <linux/init.h>
 15 #include <linux/kernel.h>
 16 #include <linux/module.h>
 17 #include <linux/slab.h>
 18 
 19 struct ccm_instance_ctx {
 20         struct crypto_skcipher_spawn ctr;
 21         struct crypto_ahash_spawn mac;
 22 };
 23 
 24 struct crypto_ccm_ctx {
 25         struct crypto_ahash *mac;
 26         struct crypto_skcipher *ctr;
 27 };
 28 
 29 struct crypto_rfc4309_ctx {
 30         struct crypto_aead *child;
 31         u8 nonce[3];
 32 };
 33 
 34 struct crypto_rfc4309_req_ctx {
 35         struct scatterlist src[3];
 36         struct scatterlist dst[3];
 37         struct aead_request subreq;
 38 };
 39 
 40 struct crypto_ccm_req_priv_ctx {
 41         u8 odata[16];
 42         u8 idata[16];
 43         u8 auth_tag[16];
 44         u32 flags;
 45         struct scatterlist src[3];
 46         struct scatterlist dst[3];
 47         union {
 48                 struct ahash_request ahreq;
 49                 struct skcipher_request skreq;
 50         };
 51 };
 52 
 53 struct cbcmac_tfm_ctx {
 54         struct crypto_cipher *child;
 55 };
 56 
 57 struct cbcmac_desc_ctx {
 58         unsigned int len;
 59         u8 dg[];
 60 };
 61 
 62 static inline struct crypto_ccm_req_priv_ctx *crypto_ccm_reqctx(
 63         struct aead_request *req)
 64 {
 65         unsigned long align = crypto_aead_alignmask(crypto_aead_reqtfm(req));
 66 
 67         return (void *)PTR_ALIGN((u8 *)aead_request_ctx(req), align + 1);
 68 }
 69 
 70 static int set_msg_len(u8 *block, unsigned int msglen, int csize)
 71 {
 72         __be32 data;
 73 
 74         memset(block, 0, csize);
 75         block += csize;
 76 
 77         if (csize >= 4)
 78                 csize = 4;
 79         else if (msglen > (1 << (8 * csize)))
 80                 return -EOVERFLOW;
 81 
 82         data = cpu_to_be32(msglen);
 83         memcpy(block - csize, (u8 *)&data + 4 - csize, csize);
 84 
 85         return 0;
 86 }
 87 
 88 static int crypto_ccm_setkey(struct crypto_aead *aead, const u8 *key,
 89                              unsigned int keylen)
 90 {
 91         struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
 92         struct crypto_skcipher *ctr = ctx->ctr;
 93         struct crypto_ahash *mac = ctx->mac;
 94         int err;
 95 
 96         crypto_skcipher_clear_flags(ctr, CRYPTO_TFM_REQ_MASK);
 97         crypto_skcipher_set_flags(ctr, crypto_aead_get_flags(aead) &
 98                                        CRYPTO_TFM_REQ_MASK);
 99         err = crypto_skcipher_setkey(ctr, key, keylen);
100         if (err)
101                 return err;
102 
103         crypto_ahash_clear_flags(mac, CRYPTO_TFM_REQ_MASK);
104         crypto_ahash_set_flags(mac, crypto_aead_get_flags(aead) &
105                                     CRYPTO_TFM_REQ_MASK);
106         return crypto_ahash_setkey(mac, key, keylen);
107 }
108 
109 static int crypto_ccm_setauthsize(struct crypto_aead *tfm,
110                                   unsigned int authsize)
111 {
112         switch (authsize) {
113         case 4:
114         case 6:
115         case 8:
116         case 10:
117         case 12:
118         case 14:
119         case 16:
120                 break;
121         default:
122                 return -EINVAL;
123         }
124 
125         return 0;
126 }
127 
128 static int format_input(u8 *info, struct aead_request *req,
129                         unsigned int cryptlen)
130 {
131         struct crypto_aead *aead = crypto_aead_reqtfm(req);
132         unsigned int lp = req->iv[0];
133         unsigned int l = lp + 1;
134         unsigned int m;
135 
136         m = crypto_aead_authsize(aead);
137 
138         memcpy(info, req->iv, 16);
139 
140         /* format control info per RFC 3610 and
141          * NIST Special Publication 800-38C
142          */
143         *info |= (8 * ((m - 2) / 2));
144         if (req->assoclen)
145                 *info |= 64;
146 
147         return set_msg_len(info + 16 - l, cryptlen, l);
148 }
149 
150 static int format_adata(u8 *adata, unsigned int a)
151 {
152         int len = 0;
153 
154         /* add control info for associated data
155          * RFC 3610 and NIST Special Publication 800-38C
156          */
157         if (a < 65280) {
158                 *(__be16 *)adata = cpu_to_be16(a);
159                 len = 2;
160         } else  {
161                 *(__be16 *)adata = cpu_to_be16(0xfffe);
162                 *(__be32 *)&adata[2] = cpu_to_be32(a);
163                 len = 6;
164         }
165 
166         return len;
167 }
168 
169 static int crypto_ccm_auth(struct aead_request *req, struct scatterlist *plain,
170                            unsigned int cryptlen)
171 {
172         struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
173         struct crypto_aead *aead = crypto_aead_reqtfm(req);
174         struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
175         struct ahash_request *ahreq = &pctx->ahreq;
176         unsigned int assoclen = req->assoclen;
177         struct scatterlist sg[3];
178         u8 *odata = pctx->odata;
179         u8 *idata = pctx->idata;
180         int ilen, err;
181 
182         /* format control data for input */
183         err = format_input(odata, req, cryptlen);
184         if (err)
185                 goto out;
186 
187         sg_init_table(sg, 3);
188         sg_set_buf(&sg[0], odata, 16);
189 
190         /* format associated data and compute into mac */
191         if (assoclen) {
192                 ilen = format_adata(idata, assoclen);
193                 sg_set_buf(&sg[1], idata, ilen);
194                 sg_chain(sg, 3, req->src);
195         } else {
196                 ilen = 0;
197                 sg_chain(sg, 2, req->src);
198         }
199 
200         ahash_request_set_tfm(ahreq, ctx->mac);
201         ahash_request_set_callback(ahreq, pctx->flags, NULL, NULL);
202         ahash_request_set_crypt(ahreq, sg, NULL, assoclen + ilen + 16);
203         err = crypto_ahash_init(ahreq);
204         if (err)
205                 goto out;
206         err = crypto_ahash_update(ahreq);
207         if (err)
208                 goto out;
209 
210         /* we need to pad the MAC input to a round multiple of the block size */
211         ilen = 16 - (assoclen + ilen) % 16;
212         if (ilen < 16) {
213                 memset(idata, 0, ilen);
214                 sg_init_table(sg, 2);
215                 sg_set_buf(&sg[0], idata, ilen);
216                 if (plain)
217                         sg_chain(sg, 2, plain);
218                 plain = sg;
219                 cryptlen += ilen;
220         }
221 
222         ahash_request_set_crypt(ahreq, plain, odata, cryptlen);
223         err = crypto_ahash_finup(ahreq);
224 out:
225         return err;
226 }
227 
228 static void crypto_ccm_encrypt_done(void *data, int err)
229 {
230         struct aead_request *req = data;
231         struct crypto_aead *aead = crypto_aead_reqtfm(req);
232         struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
233         u8 *odata = pctx->odata;
234 
235         if (!err)
236                 scatterwalk_map_and_copy(odata, req->dst,
237                                          req->assoclen + req->cryptlen,
238                                          crypto_aead_authsize(aead), 1);
239         aead_request_complete(req, err);
240 }
241 
242 static inline int crypto_ccm_check_iv(const u8 *iv)
243 {
244         /* 2 <= L <= 8, so 1 <= L' <= 7. */
245         if (1 > iv[0] || iv[0] > 7)
246                 return -EINVAL;
247 
248         return 0;
249 }
250 
251 static int crypto_ccm_init_crypt(struct aead_request *req, u8 *tag)
252 {
253         struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
254         struct scatterlist *sg;
255         u8 *iv = req->iv;
256         int err;
257 
258         err = crypto_ccm_check_iv(iv);
259         if (err)
260                 return err;
261 
262         pctx->flags = aead_request_flags(req);
263 
264          /* Note: rfc 3610 and NIST 800-38C require counter of
265          * zero to encrypt auth tag.
266          */
267         memset(iv + 15 - iv[0], 0, iv[0] + 1);
268 
269         sg_init_table(pctx->src, 3);
270         sg_set_buf(pctx->src, tag, 16);
271         sg = scatterwalk_ffwd(pctx->src + 1, req->src, req->assoclen);
272         if (sg != pctx->src + 1)
273                 sg_chain(pctx->src, 2, sg);
274 
275         if (req->src != req->dst) {
276                 sg_init_table(pctx->dst, 3);
277                 sg_set_buf(pctx->dst, tag, 16);
278                 sg = scatterwalk_ffwd(pctx->dst + 1, req->dst, req->assoclen);
279                 if (sg != pctx->dst + 1)
280                         sg_chain(pctx->dst, 2, sg);
281         }
282 
283         return 0;
284 }
285 
286 static int crypto_ccm_encrypt(struct aead_request *req)
287 {
288         struct crypto_aead *aead = crypto_aead_reqtfm(req);
289         struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
290         struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
291         struct skcipher_request *skreq = &pctx->skreq;
292         struct scatterlist *dst;
293         unsigned int cryptlen = req->cryptlen;
294         u8 *odata = pctx->odata;
295         u8 *iv = req->iv;
296         int err;
297 
298         err = crypto_ccm_init_crypt(req, odata);
299         if (err)
300                 return err;
301 
302         err = crypto_ccm_auth(req, sg_next(pctx->src), cryptlen);
303         if (err)
304                 return err;
305 
306         dst = pctx->src;
307         if (req->src != req->dst)
308                 dst = pctx->dst;
309 
310         skcipher_request_set_tfm(skreq, ctx->ctr);
311         skcipher_request_set_callback(skreq, pctx->flags,
312                                       crypto_ccm_encrypt_done, req);
313         skcipher_request_set_crypt(skreq, pctx->src, dst, cryptlen + 16, iv);
314         err = crypto_skcipher_encrypt(skreq);
315         if (err)
316                 return err;
317 
318         /* copy authtag to end of dst */
319         scatterwalk_map_and_copy(odata, sg_next(dst), cryptlen,
320                                  crypto_aead_authsize(aead), 1);
321         return err;
322 }
323 
324 static void crypto_ccm_decrypt_done(void *data, int err)
325 {
326         struct aead_request *req = data;
327         struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
328         struct crypto_aead *aead = crypto_aead_reqtfm(req);
329         unsigned int authsize = crypto_aead_authsize(aead);
330         unsigned int cryptlen = req->cryptlen - authsize;
331         struct scatterlist *dst;
332 
333         pctx->flags = 0;
334 
335         dst = sg_next(req->src == req->dst ? pctx->src : pctx->dst);
336 
337         if (!err) {
338                 err = crypto_ccm_auth(req, dst, cryptlen);
339                 if (!err && crypto_memneq(pctx->auth_tag, pctx->odata, authsize))
340                         err = -EBADMSG;
341         }
342         aead_request_complete(req, err);
343 }
344 
345 static int crypto_ccm_decrypt(struct aead_request *req)
346 {
347         struct crypto_aead *aead = crypto_aead_reqtfm(req);
348         struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
349         struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
350         struct skcipher_request *skreq = &pctx->skreq;
351         struct scatterlist *dst;
352         unsigned int authsize = crypto_aead_authsize(aead);
353         unsigned int cryptlen = req->cryptlen;
354         u8 *authtag = pctx->auth_tag;
355         u8 *odata = pctx->odata;
356         u8 *iv = pctx->idata;
357         int err;
358 
359         cryptlen -= authsize;
360 
361         err = crypto_ccm_init_crypt(req, authtag);
362         if (err)
363                 return err;
364 
365         scatterwalk_map_and_copy(authtag, sg_next(pctx->src), cryptlen,
366                                  authsize, 0);
367 
368         dst = pctx->src;
369         if (req->src != req->dst)
370                 dst = pctx->dst;
371 
372         memcpy(iv, req->iv, 16);
373 
374         skcipher_request_set_tfm(skreq, ctx->ctr);
375         skcipher_request_set_callback(skreq, pctx->flags,
376                                       crypto_ccm_decrypt_done, req);
377         skcipher_request_set_crypt(skreq, pctx->src, dst, cryptlen + 16, iv);
378         err = crypto_skcipher_decrypt(skreq);
379         if (err)
380                 return err;
381 
382         err = crypto_ccm_auth(req, sg_next(dst), cryptlen);
383         if (err)
384                 return err;
385 
386         /* verify */
387         if (crypto_memneq(authtag, odata, authsize))
388                 return -EBADMSG;
389 
390         return err;
391 }
392 
393 static int crypto_ccm_init_tfm(struct crypto_aead *tfm)
394 {
395         struct aead_instance *inst = aead_alg_instance(tfm);
396         struct ccm_instance_ctx *ictx = aead_instance_ctx(inst);
397         struct crypto_ccm_ctx *ctx = crypto_aead_ctx(tfm);
398         struct crypto_ahash *mac;
399         struct crypto_skcipher *ctr;
400         unsigned long align;
401         int err;
402 
403         mac = crypto_spawn_ahash(&ictx->mac);
404         if (IS_ERR(mac))
405                 return PTR_ERR(mac);
406 
407         ctr = crypto_spawn_skcipher(&ictx->ctr);
408         err = PTR_ERR(ctr);
409         if (IS_ERR(ctr))
410                 goto err_free_mac;
411 
412         ctx->mac = mac;
413         ctx->ctr = ctr;
414 
415         align = crypto_aead_alignmask(tfm);
416         align &= ~(crypto_tfm_ctx_alignment() - 1);
417         crypto_aead_set_reqsize(
418                 tfm,
419                 align + sizeof(struct crypto_ccm_req_priv_ctx) +
420                 max(crypto_ahash_reqsize(mac), crypto_skcipher_reqsize(ctr)));
421 
422         return 0;
423 
424 err_free_mac:
425         crypto_free_ahash(mac);
426         return err;
427 }
428 
429 static void crypto_ccm_exit_tfm(struct crypto_aead *tfm)
430 {
431         struct crypto_ccm_ctx *ctx = crypto_aead_ctx(tfm);
432 
433         crypto_free_ahash(ctx->mac);
434         crypto_free_skcipher(ctx->ctr);
435 }
436 
437 static void crypto_ccm_free(struct aead_instance *inst)
438 {
439         struct ccm_instance_ctx *ctx = aead_instance_ctx(inst);
440 
441         crypto_drop_ahash(&ctx->mac);
442         crypto_drop_skcipher(&ctx->ctr);
443         kfree(inst);
444 }
445 
446 static int crypto_ccm_create_common(struct crypto_template *tmpl,
447                                     struct rtattr **tb,
448                                     const char *ctr_name,
449                                     const char *mac_name)
450 {
451         struct skcipher_alg_common *ctr;
452         u32 mask;
453         struct aead_instance *inst;
454         struct ccm_instance_ctx *ictx;
455         struct hash_alg_common *mac;
456         int err;
457 
458         err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_AEAD, &mask);
459         if (err)
460                 return err;
461 
462         inst = kzalloc(sizeof(*inst) + sizeof(*ictx), GFP_KERNEL);
463         if (!inst)
464                 return -ENOMEM;
465         ictx = aead_instance_ctx(inst);
466 
467         err = crypto_grab_ahash(&ictx->mac, aead_crypto_instance(inst),
468                                 mac_name, 0, mask | CRYPTO_ALG_ASYNC);
469         if (err)
470                 goto err_free_inst;
471         mac = crypto_spawn_ahash_alg(&ictx->mac);
472 
473         err = -EINVAL;
474         if (strncmp(mac->base.cra_name, "cbcmac(", 7) != 0 ||
475             mac->digestsize != 16)
476                 goto err_free_inst;
477 
478         err = crypto_grab_skcipher(&ictx->ctr, aead_crypto_instance(inst),
479                                    ctr_name, 0, mask);
480         if (err)
481                 goto err_free_inst;
482         ctr = crypto_spawn_skcipher_alg_common(&ictx->ctr);
483 
484         /* The skcipher algorithm must be CTR mode, using 16-byte blocks. */
485         err = -EINVAL;
486         if (strncmp(ctr->base.cra_name, "ctr(", 4) != 0 ||
487             ctr->ivsize != 16 || ctr->base.cra_blocksize != 1)
488                 goto err_free_inst;
489 
490         /* ctr and cbcmac must use the same underlying block cipher. */
491         if (strcmp(ctr->base.cra_name + 4, mac->base.cra_name + 7) != 0)
492                 goto err_free_inst;
493 
494         err = -ENAMETOOLONG;
495         if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
496                      "ccm(%s", ctr->base.cra_name + 4) >= CRYPTO_MAX_ALG_NAME)
497                 goto err_free_inst;
498 
499         if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
500                      "ccm_base(%s,%s)", ctr->base.cra_driver_name,
501                      mac->base.cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
502                 goto err_free_inst;
503 
504         inst->alg.base.cra_priority = (mac->base.cra_priority +
505                                        ctr->base.cra_priority) / 2;
506         inst->alg.base.cra_blocksize = 1;
507         inst->alg.base.cra_alignmask = ctr->base.cra_alignmask;
508         inst->alg.ivsize = 16;
509         inst->alg.chunksize = ctr->chunksize;
510         inst->alg.maxauthsize = 16;
511         inst->alg.base.cra_ctxsize = sizeof(struct crypto_ccm_ctx);
512         inst->alg.init = crypto_ccm_init_tfm;
513         inst->alg.exit = crypto_ccm_exit_tfm;
514         inst->alg.setkey = crypto_ccm_setkey;
515         inst->alg.setauthsize = crypto_ccm_setauthsize;
516         inst->alg.encrypt = crypto_ccm_encrypt;
517         inst->alg.decrypt = crypto_ccm_decrypt;
518 
519         inst->free = crypto_ccm_free;
520 
521         err = aead_register_instance(tmpl, inst);
522         if (err) {
523 err_free_inst:
524                 crypto_ccm_free(inst);
525         }
526         return err;
527 }
528 
529 static int crypto_ccm_create(struct crypto_template *tmpl, struct rtattr **tb)
530 {
531         const char *cipher_name;
532         char ctr_name[CRYPTO_MAX_ALG_NAME];
533         char mac_name[CRYPTO_MAX_ALG_NAME];
534 
535         cipher_name = crypto_attr_alg_name(tb[1]);
536         if (IS_ERR(cipher_name))
537                 return PTR_ERR(cipher_name);
538 
539         if (snprintf(ctr_name, CRYPTO_MAX_ALG_NAME, "ctr(%s)",
540                      cipher_name) >= CRYPTO_MAX_ALG_NAME)
541                 return -ENAMETOOLONG;
542 
543         if (snprintf(mac_name, CRYPTO_MAX_ALG_NAME, "cbcmac(%s)",
544                      cipher_name) >= CRYPTO_MAX_ALG_NAME)
545                 return -ENAMETOOLONG;
546 
547         return crypto_ccm_create_common(tmpl, tb, ctr_name, mac_name);
548 }
549 
550 static int crypto_ccm_base_create(struct crypto_template *tmpl,
551                                   struct rtattr **tb)
552 {
553         const char *ctr_name;
554         const char *mac_name;
555 
556         ctr_name = crypto_attr_alg_name(tb[1]);
557         if (IS_ERR(ctr_name))
558                 return PTR_ERR(ctr_name);
559 
560         mac_name = crypto_attr_alg_name(tb[2]);
561         if (IS_ERR(mac_name))
562                 return PTR_ERR(mac_name);
563 
564         return crypto_ccm_create_common(tmpl, tb, ctr_name, mac_name);
565 }
566 
567 static int crypto_rfc4309_setkey(struct crypto_aead *parent, const u8 *key,
568                                  unsigned int keylen)
569 {
570         struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(parent);
571         struct crypto_aead *child = ctx->child;
572 
573         if (keylen < 3)
574                 return -EINVAL;
575 
576         keylen -= 3;
577         memcpy(ctx->nonce, key + keylen, 3);
578 
579         crypto_aead_clear_flags(child, CRYPTO_TFM_REQ_MASK);
580         crypto_aead_set_flags(child, crypto_aead_get_flags(parent) &
581                                      CRYPTO_TFM_REQ_MASK);
582         return crypto_aead_setkey(child, key, keylen);
583 }
584 
585 static int crypto_rfc4309_setauthsize(struct crypto_aead *parent,
586                                       unsigned int authsize)
587 {
588         struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(parent);
589 
590         switch (authsize) {
591         case 8:
592         case 12:
593         case 16:
594                 break;
595         default:
596                 return -EINVAL;
597         }
598 
599         return crypto_aead_setauthsize(ctx->child, authsize);
600 }
601 
602 static struct aead_request *crypto_rfc4309_crypt(struct aead_request *req)
603 {
604         struct crypto_rfc4309_req_ctx *rctx = aead_request_ctx(req);
605         struct aead_request *subreq = &rctx->subreq;
606         struct crypto_aead *aead = crypto_aead_reqtfm(req);
607         struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(aead);
608         struct crypto_aead *child = ctx->child;
609         struct scatterlist *sg;
610         u8 *iv = PTR_ALIGN((u8 *)(subreq + 1) + crypto_aead_reqsize(child),
611                            crypto_aead_alignmask(child) + 1);
612 
613         /* L' */
614         iv[0] = 3;
615 
616         memcpy(iv + 1, ctx->nonce, 3);
617         memcpy(iv + 4, req->iv, 8);
618 
619         scatterwalk_map_and_copy(iv + 16, req->src, 0, req->assoclen - 8, 0);
620 
621         sg_init_table(rctx->src, 3);
622         sg_set_buf(rctx->src, iv + 16, req->assoclen - 8);
623         sg = scatterwalk_ffwd(rctx->src + 1, req->src, req->assoclen);
624         if (sg != rctx->src + 1)
625                 sg_chain(rctx->src, 2, sg);
626 
627         if (req->src != req->dst) {
628                 sg_init_table(rctx->dst, 3);
629                 sg_set_buf(rctx->dst, iv + 16, req->assoclen - 8);
630                 sg = scatterwalk_ffwd(rctx->dst + 1, req->dst, req->assoclen);
631                 if (sg != rctx->dst + 1)
632                         sg_chain(rctx->dst, 2, sg);
633         }
634 
635         aead_request_set_tfm(subreq, child);
636         aead_request_set_callback(subreq, req->base.flags, req->base.complete,
637                                   req->base.data);
638         aead_request_set_crypt(subreq, rctx->src,
639                                req->src == req->dst ? rctx->src : rctx->dst,
640                                req->cryptlen, iv);
641         aead_request_set_ad(subreq, req->assoclen - 8);
642 
643         return subreq;
644 }
645 
646 static int crypto_rfc4309_encrypt(struct aead_request *req)
647 {
648         if (req->assoclen != 16 && req->assoclen != 20)
649                 return -EINVAL;
650 
651         req = crypto_rfc4309_crypt(req);
652 
653         return crypto_aead_encrypt(req);
654 }
655 
656 static int crypto_rfc4309_decrypt(struct aead_request *req)
657 {
658         if (req->assoclen != 16 && req->assoclen != 20)
659                 return -EINVAL;
660 
661         req = crypto_rfc4309_crypt(req);
662 
663         return crypto_aead_decrypt(req);
664 }
665 
666 static int crypto_rfc4309_init_tfm(struct crypto_aead *tfm)
667 {
668         struct aead_instance *inst = aead_alg_instance(tfm);
669         struct crypto_aead_spawn *spawn = aead_instance_ctx(inst);
670         struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(tfm);
671         struct crypto_aead *aead;
672         unsigned long align;
673 
674         aead = crypto_spawn_aead(spawn);
675         if (IS_ERR(aead))
676                 return PTR_ERR(aead);
677 
678         ctx->child = aead;
679 
680         align = crypto_aead_alignmask(aead);
681         align &= ~(crypto_tfm_ctx_alignment() - 1);
682         crypto_aead_set_reqsize(
683                 tfm,
684                 sizeof(struct crypto_rfc4309_req_ctx) +
685                 ALIGN(crypto_aead_reqsize(aead), crypto_tfm_ctx_alignment()) +
686                 align + 32);
687 
688         return 0;
689 }
690 
691 static void crypto_rfc4309_exit_tfm(struct crypto_aead *tfm)
692 {
693         struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(tfm);
694 
695         crypto_free_aead(ctx->child);
696 }
697 
698 static void crypto_rfc4309_free(struct aead_instance *inst)
699 {
700         crypto_drop_aead(aead_instance_ctx(inst));
701         kfree(inst);
702 }
703 
704 static int crypto_rfc4309_create(struct crypto_template *tmpl,
705                                  struct rtattr **tb)
706 {
707         u32 mask;
708         struct aead_instance *inst;
709         struct crypto_aead_spawn *spawn;
710         struct aead_alg *alg;
711         int err;
712 
713         err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_AEAD, &mask);
714         if (err)
715                 return err;
716 
717         inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
718         if (!inst)
719                 return -ENOMEM;
720 
721         spawn = aead_instance_ctx(inst);
722         err = crypto_grab_aead(spawn, aead_crypto_instance(inst),
723                                crypto_attr_alg_name(tb[1]), 0, mask);
724         if (err)
725                 goto err_free_inst;
726 
727         alg = crypto_spawn_aead_alg(spawn);
728 
729         err = -EINVAL;
730 
731         /* We only support 16-byte blocks. */
732         if (crypto_aead_alg_ivsize(alg) != 16)
733                 goto err_free_inst;
734 
735         /* Not a stream cipher? */
736         if (alg->base.cra_blocksize != 1)
737                 goto err_free_inst;
738 
739         err = -ENAMETOOLONG;
740         if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
741                      "rfc4309(%s)", alg->base.cra_name) >=
742             CRYPTO_MAX_ALG_NAME ||
743             snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
744                      "rfc4309(%s)", alg->base.cra_driver_name) >=
745             CRYPTO_MAX_ALG_NAME)
746                 goto err_free_inst;
747 
748         inst->alg.base.cra_priority = alg->base.cra_priority;
749         inst->alg.base.cra_blocksize = 1;
750         inst->alg.base.cra_alignmask = alg->base.cra_alignmask;
751 
752         inst->alg.ivsize = 8;
753         inst->alg.chunksize = crypto_aead_alg_chunksize(alg);
754         inst->alg.maxauthsize = 16;
755 
756         inst->alg.base.cra_ctxsize = sizeof(struct crypto_rfc4309_ctx);
757 
758         inst->alg.init = crypto_rfc4309_init_tfm;
759         inst->alg.exit = crypto_rfc4309_exit_tfm;
760 
761         inst->alg.setkey = crypto_rfc4309_setkey;
762         inst->alg.setauthsize = crypto_rfc4309_setauthsize;
763         inst->alg.encrypt = crypto_rfc4309_encrypt;
764         inst->alg.decrypt = crypto_rfc4309_decrypt;
765 
766         inst->free = crypto_rfc4309_free;
767 
768         err = aead_register_instance(tmpl, inst);
769         if (err) {
770 err_free_inst:
771                 crypto_rfc4309_free(inst);
772         }
773         return err;
774 }
775 
776 static int crypto_cbcmac_digest_setkey(struct crypto_shash *parent,
777                                      const u8 *inkey, unsigned int keylen)
778 {
779         struct cbcmac_tfm_ctx *ctx = crypto_shash_ctx(parent);
780 
781         return crypto_cipher_setkey(ctx->child, inkey, keylen);
782 }
783 
784 static int crypto_cbcmac_digest_init(struct shash_desc *pdesc)
785 {
786         struct cbcmac_desc_ctx *ctx = shash_desc_ctx(pdesc);
787         int bs = crypto_shash_digestsize(pdesc->tfm);
788 
789         ctx->len = 0;
790         memset(ctx->dg, 0, bs);
791 
792         return 0;
793 }
794 
795 static int crypto_cbcmac_digest_update(struct shash_desc *pdesc, const u8 *p,
796                                        unsigned int len)
797 {
798         struct crypto_shash *parent = pdesc->tfm;
799         struct cbcmac_tfm_ctx *tctx = crypto_shash_ctx(parent);
800         struct cbcmac_desc_ctx *ctx = shash_desc_ctx(pdesc);
801         struct crypto_cipher *tfm = tctx->child;
802         int bs = crypto_shash_digestsize(parent);
803 
804         while (len > 0) {
805                 unsigned int l = min(len, bs - ctx->len);
806 
807                 crypto_xor(&ctx->dg[ctx->len], p, l);
808                 ctx->len +=l;
809                 len -= l;
810                 p += l;
811 
812                 if (ctx->len == bs) {
813                         crypto_cipher_encrypt_one(tfm, ctx->dg, ctx->dg);
814                         ctx->len = 0;
815                 }
816         }
817 
818         return 0;
819 }
820 
821 static int crypto_cbcmac_digest_final(struct shash_desc *pdesc, u8 *out)
822 {
823         struct crypto_shash *parent = pdesc->tfm;
824         struct cbcmac_tfm_ctx *tctx = crypto_shash_ctx(parent);
825         struct cbcmac_desc_ctx *ctx = shash_desc_ctx(pdesc);
826         struct crypto_cipher *tfm = tctx->child;
827         int bs = crypto_shash_digestsize(parent);
828 
829         if (ctx->len)
830                 crypto_cipher_encrypt_one(tfm, ctx->dg, ctx->dg);
831 
832         memcpy(out, ctx->dg, bs);
833         return 0;
834 }
835 
836 static int cbcmac_init_tfm(struct crypto_tfm *tfm)
837 {
838         struct crypto_cipher *cipher;
839         struct crypto_instance *inst = (void *)tfm->__crt_alg;
840         struct crypto_cipher_spawn *spawn = crypto_instance_ctx(inst);
841         struct cbcmac_tfm_ctx *ctx = crypto_tfm_ctx(tfm);
842 
843         cipher = crypto_spawn_cipher(spawn);
844         if (IS_ERR(cipher))
845                 return PTR_ERR(cipher);
846 
847         ctx->child = cipher;
848 
849         return 0;
850 };
851 
852 static void cbcmac_exit_tfm(struct crypto_tfm *tfm)
853 {
854         struct cbcmac_tfm_ctx *ctx = crypto_tfm_ctx(tfm);
855         crypto_free_cipher(ctx->child);
856 }
857 
858 static int cbcmac_create(struct crypto_template *tmpl, struct rtattr **tb)
859 {
860         struct shash_instance *inst;
861         struct crypto_cipher_spawn *spawn;
862         struct crypto_alg *alg;
863         u32 mask;
864         int err;
865 
866         err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SHASH, &mask);
867         if (err)
868                 return err;
869 
870         inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
871         if (!inst)
872                 return -ENOMEM;
873         spawn = shash_instance_ctx(inst);
874 
875         err = crypto_grab_cipher(spawn, shash_crypto_instance(inst),
876                                  crypto_attr_alg_name(tb[1]), 0, mask);
877         if (err)
878                 goto err_free_inst;
879         alg = crypto_spawn_cipher_alg(spawn);
880 
881         err = crypto_inst_setname(shash_crypto_instance(inst), tmpl->name, alg);
882         if (err)
883                 goto err_free_inst;
884 
885         inst->alg.base.cra_priority = alg->cra_priority;
886         inst->alg.base.cra_blocksize = 1;
887 
888         inst->alg.digestsize = alg->cra_blocksize;
889         inst->alg.descsize = sizeof(struct cbcmac_desc_ctx) +
890                              alg->cra_blocksize;
891 
892         inst->alg.base.cra_ctxsize = sizeof(struct cbcmac_tfm_ctx);
893         inst->alg.base.cra_init = cbcmac_init_tfm;
894         inst->alg.base.cra_exit = cbcmac_exit_tfm;
895 
896         inst->alg.init = crypto_cbcmac_digest_init;
897         inst->alg.update = crypto_cbcmac_digest_update;
898         inst->alg.final = crypto_cbcmac_digest_final;
899         inst->alg.setkey = crypto_cbcmac_digest_setkey;
900 
901         inst->free = shash_free_singlespawn_instance;
902 
903         err = shash_register_instance(tmpl, inst);
904         if (err) {
905 err_free_inst:
906                 shash_free_singlespawn_instance(inst);
907         }
908         return err;
909 }
910 
911 static struct crypto_template crypto_ccm_tmpls[] = {
912         {
913                 .name = "cbcmac",
914                 .create = cbcmac_create,
915                 .module = THIS_MODULE,
916         }, {
917                 .name = "ccm_base",
918                 .create = crypto_ccm_base_create,
919                 .module = THIS_MODULE,
920         }, {
921                 .name = "ccm",
922                 .create = crypto_ccm_create,
923                 .module = THIS_MODULE,
924         }, {
925                 .name = "rfc4309",
926                 .create = crypto_rfc4309_create,
927                 .module = THIS_MODULE,
928         },
929 };
930 
931 static int __init crypto_ccm_module_init(void)
932 {
933         return crypto_register_templates(crypto_ccm_tmpls,
934                                          ARRAY_SIZE(crypto_ccm_tmpls));
935 }
936 
937 static void __exit crypto_ccm_module_exit(void)
938 {
939         crypto_unregister_templates(crypto_ccm_tmpls,
940                                     ARRAY_SIZE(crypto_ccm_tmpls));
941 }
942 
943 subsys_initcall(crypto_ccm_module_init);
944 module_exit(crypto_ccm_module_exit);
945 
946 MODULE_LICENSE("GPL");
947 MODULE_DESCRIPTION("Counter with CBC MAC");
948 MODULE_ALIAS_CRYPTO("ccm_base");
949 MODULE_ALIAS_CRYPTO("rfc4309");
950 MODULE_ALIAS_CRYPTO("ccm");
951 MODULE_ALIAS_CRYPTO("cbcmac");
952 MODULE_IMPORT_NS(CRYPTO_INTERNAL);
953 

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