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TOMOYO Linux Cross Reference
Linux/crypto/ccm.c

Version: ~ [ linux-5.6-rc1 ] ~ [ linux-5.5.2 ] ~ [ linux-5.4.17 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.102 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.170 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.213 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.213 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.81 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-3.9.11 ] ~ [ linux-3.8.13 ] ~ [ linux-3.7.10 ] ~ [ linux-3.6.11 ] ~ [ linux-3.5.7 ] ~ [ linux-3.4.113 ] ~ [ linux-3.3.8 ] ~ [ linux-3.2.102 ] ~ [ linux-3.1.10 ] ~ [ linux-3.0.101 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 /*
  2  * CCM: Counter with CBC-MAC
  3  *
  4  * (C) Copyright IBM Corp. 2007 - Joy Latten <latten@us.ibm.com>
  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/internal/aead.h>
 14 #include <crypto/internal/skcipher.h>
 15 #include <crypto/scatterwalk.h>
 16 #include <linux/err.h>
 17 #include <linux/init.h>
 18 #include <linux/kernel.h>
 19 #include <linux/module.h>
 20 #include <linux/slab.h>
 21 
 22 #include "internal.h"
 23 
 24 struct ccm_instance_ctx {
 25         struct crypto_skcipher_spawn ctr;
 26         struct crypto_spawn cipher;
 27 };
 28 
 29 struct crypto_ccm_ctx {
 30         struct crypto_cipher *cipher;
 31         struct crypto_ablkcipher *ctr;
 32 };
 33 
 34 struct crypto_rfc4309_ctx {
 35         struct crypto_aead *child;
 36         u8 nonce[3];
 37 };
 38 
 39 struct crypto_ccm_req_priv_ctx {
 40         u8 odata[16];
 41         u8 idata[16];
 42         u8 auth_tag[16];
 43         u32 ilen;
 44         u32 flags;
 45         struct scatterlist src[2];
 46         struct scatterlist dst[2];
 47         struct ablkcipher_request abreq;
 48 };
 49 
 50 static inline struct crypto_ccm_req_priv_ctx *crypto_ccm_reqctx(
 51         struct aead_request *req)
 52 {
 53         unsigned long align = crypto_aead_alignmask(crypto_aead_reqtfm(req));
 54 
 55         return (void *)PTR_ALIGN((u8 *)aead_request_ctx(req), align + 1);
 56 }
 57 
 58 static int set_msg_len(u8 *block, unsigned int msglen, int csize)
 59 {
 60         __be32 data;
 61 
 62         memset(block, 0, csize);
 63         block += csize;
 64 
 65         if (csize >= 4)
 66                 csize = 4;
 67         else if (msglen > (1 << (8 * csize)))
 68                 return -EOVERFLOW;
 69 
 70         data = cpu_to_be32(msglen);
 71         memcpy(block - csize, (u8 *)&data + 4 - csize, csize);
 72 
 73         return 0;
 74 }
 75 
 76 static int crypto_ccm_setkey(struct crypto_aead *aead, const u8 *key,
 77                              unsigned int keylen)
 78 {
 79         struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
 80         struct crypto_ablkcipher *ctr = ctx->ctr;
 81         struct crypto_cipher *tfm = ctx->cipher;
 82         int err = 0;
 83 
 84         crypto_ablkcipher_clear_flags(ctr, CRYPTO_TFM_REQ_MASK);
 85         crypto_ablkcipher_set_flags(ctr, crypto_aead_get_flags(aead) &
 86                                     CRYPTO_TFM_REQ_MASK);
 87         err = crypto_ablkcipher_setkey(ctr, key, keylen);
 88         crypto_aead_set_flags(aead, crypto_ablkcipher_get_flags(ctr) &
 89                               CRYPTO_TFM_RES_MASK);
 90         if (err)
 91                 goto out;
 92 
 93         crypto_cipher_clear_flags(tfm, CRYPTO_TFM_REQ_MASK);
 94         crypto_cipher_set_flags(tfm, crypto_aead_get_flags(aead) &
 95                                     CRYPTO_TFM_REQ_MASK);
 96         err = crypto_cipher_setkey(tfm, key, keylen);
 97         crypto_aead_set_flags(aead, crypto_cipher_get_flags(tfm) &
 98                               CRYPTO_TFM_RES_MASK);
 99 
100 out:
101         return err;
102 }
103 
104 static int crypto_ccm_setauthsize(struct crypto_aead *tfm,
105                                   unsigned int authsize)
106 {
107         switch (authsize) {
108         case 4:
109         case 6:
110         case 8:
111         case 10:
112         case 12:
113         case 14:
114         case 16:
115                 break;
116         default:
117                 return -EINVAL;
118         }
119 
120         return 0;
121 }
122 
123 static int format_input(u8 *info, struct aead_request *req,
124                         unsigned int cryptlen)
125 {
126         struct crypto_aead *aead = crypto_aead_reqtfm(req);
127         unsigned int lp = req->iv[0];
128         unsigned int l = lp + 1;
129         unsigned int m;
130 
131         m = crypto_aead_authsize(aead);
132 
133         memcpy(info, req->iv, 16);
134 
135         /* format control info per RFC 3610 and
136          * NIST Special Publication 800-38C
137          */
138         *info |= (8 * ((m - 2) / 2));
139         if (req->assoclen)
140                 *info |= 64;
141 
142         return set_msg_len(info + 16 - l, cryptlen, l);
143 }
144 
145 static int format_adata(u8 *adata, unsigned int a)
146 {
147         int len = 0;
148 
149         /* add control info for associated data
150          * RFC 3610 and NIST Special Publication 800-38C
151          */
152         if (a < 65280) {
153                 *(__be16 *)adata = cpu_to_be16(a);
154                 len = 2;
155         } else  {
156                 *(__be16 *)adata = cpu_to_be16(0xfffe);
157                 *(__be32 *)&adata[2] = cpu_to_be32(a);
158                 len = 6;
159         }
160 
161         return len;
162 }
163 
164 static void compute_mac(struct crypto_cipher *tfm, u8 *data, int n,
165                        struct crypto_ccm_req_priv_ctx *pctx)
166 {
167         unsigned int bs = 16;
168         u8 *odata = pctx->odata;
169         u8 *idata = pctx->idata;
170         int datalen, getlen;
171 
172         datalen = n;
173 
174         /* first time in here, block may be partially filled. */
175         getlen = bs - pctx->ilen;
176         if (datalen >= getlen) {
177                 memcpy(idata + pctx->ilen, data, getlen);
178                 crypto_xor(odata, idata, bs);
179                 crypto_cipher_encrypt_one(tfm, odata, odata);
180                 datalen -= getlen;
181                 data += getlen;
182                 pctx->ilen = 0;
183         }
184 
185         /* now encrypt rest of data */
186         while (datalen >= bs) {
187                 crypto_xor(odata, data, bs);
188                 crypto_cipher_encrypt_one(tfm, odata, odata);
189 
190                 datalen -= bs;
191                 data += bs;
192         }
193 
194         /* check and see if there's leftover data that wasn't
195          * enough to fill a block.
196          */
197         if (datalen) {
198                 memcpy(idata + pctx->ilen, data, datalen);
199                 pctx->ilen += datalen;
200         }
201 }
202 
203 static void get_data_to_compute(struct crypto_cipher *tfm,
204                                struct crypto_ccm_req_priv_ctx *pctx,
205                                struct scatterlist *sg, unsigned int len)
206 {
207         struct scatter_walk walk;
208         u8 *data_src;
209         int n;
210 
211         scatterwalk_start(&walk, sg);
212 
213         while (len) {
214                 n = scatterwalk_clamp(&walk, len);
215                 if (!n) {
216                         scatterwalk_start(&walk, sg_next(walk.sg));
217                         n = scatterwalk_clamp(&walk, len);
218                 }
219                 data_src = scatterwalk_map(&walk);
220 
221                 compute_mac(tfm, data_src, n, pctx);
222                 len -= n;
223 
224                 scatterwalk_unmap(data_src);
225                 scatterwalk_advance(&walk, n);
226                 scatterwalk_done(&walk, 0, len);
227                 if (len)
228                         crypto_yield(pctx->flags);
229         }
230 
231         /* any leftover needs padding and then encrypted */
232         if (pctx->ilen) {
233                 int padlen;
234                 u8 *odata = pctx->odata;
235                 u8 *idata = pctx->idata;
236 
237                 padlen = 16 - pctx->ilen;
238                 memset(idata + pctx->ilen, 0, padlen);
239                 crypto_xor(odata, idata, 16);
240                 crypto_cipher_encrypt_one(tfm, odata, odata);
241                 pctx->ilen = 0;
242         }
243 }
244 
245 static int crypto_ccm_auth(struct aead_request *req, struct scatterlist *plain,
246                            unsigned int cryptlen)
247 {
248         struct crypto_aead *aead = crypto_aead_reqtfm(req);
249         struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
250         struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
251         struct crypto_cipher *cipher = ctx->cipher;
252         unsigned int assoclen = req->assoclen;
253         u8 *odata = pctx->odata;
254         u8 *idata = pctx->idata;
255         int err;
256 
257         /* format control data for input */
258         err = format_input(odata, req, cryptlen);
259         if (err)
260                 goto out;
261 
262         /* encrypt first block to use as start in computing mac  */
263         crypto_cipher_encrypt_one(cipher, odata, odata);
264 
265         /* format associated data and compute into mac */
266         if (assoclen) {
267                 pctx->ilen = format_adata(idata, assoclen);
268                 get_data_to_compute(cipher, pctx, req->assoc, req->assoclen);
269         } else {
270                 pctx->ilen = 0;
271         }
272 
273         /* compute plaintext into mac */
274         if (cryptlen)
275                 get_data_to_compute(cipher, pctx, plain, cryptlen);
276 
277 out:
278         return err;
279 }
280 
281 static void crypto_ccm_encrypt_done(struct crypto_async_request *areq, int err)
282 {
283         struct aead_request *req = areq->data;
284         struct crypto_aead *aead = crypto_aead_reqtfm(req);
285         struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
286         u8 *odata = pctx->odata;
287 
288         if (!err)
289                 scatterwalk_map_and_copy(odata, req->dst, req->cryptlen,
290                                          crypto_aead_authsize(aead), 1);
291         aead_request_complete(req, err);
292 }
293 
294 static inline int crypto_ccm_check_iv(const u8 *iv)
295 {
296         /* 2 <= L <= 8, so 1 <= L' <= 7. */
297         if (1 > iv[0] || iv[0] > 7)
298                 return -EINVAL;
299 
300         return 0;
301 }
302 
303 static int crypto_ccm_encrypt(struct aead_request *req)
304 {
305         struct crypto_aead *aead = crypto_aead_reqtfm(req);
306         struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
307         struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
308         struct ablkcipher_request *abreq = &pctx->abreq;
309         struct scatterlist *dst;
310         unsigned int cryptlen = req->cryptlen;
311         u8 *odata = pctx->odata;
312         u8 *iv = req->iv;
313         int err;
314 
315         err = crypto_ccm_check_iv(iv);
316         if (err)
317                 return err;
318 
319         pctx->flags = aead_request_flags(req);
320 
321         err = crypto_ccm_auth(req, req->src, cryptlen);
322         if (err)
323                 return err;
324 
325          /* Note: rfc 3610 and NIST 800-38C require counter of
326          * zero to encrypt auth tag.
327          */
328         memset(iv + 15 - iv[0], 0, iv[0] + 1);
329 
330         sg_init_table(pctx->src, 2);
331         sg_set_buf(pctx->src, odata, 16);
332         scatterwalk_sg_chain(pctx->src, 2, req->src);
333 
334         dst = pctx->src;
335         if (req->src != req->dst) {
336                 sg_init_table(pctx->dst, 2);
337                 sg_set_buf(pctx->dst, odata, 16);
338                 scatterwalk_sg_chain(pctx->dst, 2, req->dst);
339                 dst = pctx->dst;
340         }
341 
342         ablkcipher_request_set_tfm(abreq, ctx->ctr);
343         ablkcipher_request_set_callback(abreq, pctx->flags,
344                                         crypto_ccm_encrypt_done, req);
345         ablkcipher_request_set_crypt(abreq, pctx->src, dst, cryptlen + 16, iv);
346         err = crypto_ablkcipher_encrypt(abreq);
347         if (err)
348                 return err;
349 
350         /* copy authtag to end of dst */
351         scatterwalk_map_and_copy(odata, req->dst, cryptlen,
352                                  crypto_aead_authsize(aead), 1);
353         return err;
354 }
355 
356 static void crypto_ccm_decrypt_done(struct crypto_async_request *areq,
357                                    int err)
358 {
359         struct aead_request *req = areq->data;
360         struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
361         struct crypto_aead *aead = crypto_aead_reqtfm(req);
362         unsigned int authsize = crypto_aead_authsize(aead);
363         unsigned int cryptlen = req->cryptlen - authsize;
364 
365         if (!err) {
366                 err = crypto_ccm_auth(req, req->dst, cryptlen);
367                 if (!err && crypto_memneq(pctx->auth_tag, pctx->odata, authsize))
368                         err = -EBADMSG;
369         }
370         aead_request_complete(req, err);
371 }
372 
373 static int crypto_ccm_decrypt(struct aead_request *req)
374 {
375         struct crypto_aead *aead = crypto_aead_reqtfm(req);
376         struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
377         struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
378         struct ablkcipher_request *abreq = &pctx->abreq;
379         struct scatterlist *dst;
380         unsigned int authsize = crypto_aead_authsize(aead);
381         unsigned int cryptlen = req->cryptlen;
382         u8 *authtag = pctx->auth_tag;
383         u8 *odata = pctx->odata;
384         u8 *iv = req->iv;
385         int err;
386 
387         if (cryptlen < authsize)
388                 return -EINVAL;
389         cryptlen -= authsize;
390 
391         err = crypto_ccm_check_iv(iv);
392         if (err)
393                 return err;
394 
395         pctx->flags = aead_request_flags(req);
396 
397         scatterwalk_map_and_copy(authtag, req->src, cryptlen, authsize, 0);
398 
399         memset(iv + 15 - iv[0], 0, iv[0] + 1);
400 
401         sg_init_table(pctx->src, 2);
402         sg_set_buf(pctx->src, authtag, 16);
403         scatterwalk_sg_chain(pctx->src, 2, req->src);
404 
405         dst = pctx->src;
406         if (req->src != req->dst) {
407                 sg_init_table(pctx->dst, 2);
408                 sg_set_buf(pctx->dst, authtag, 16);
409                 scatterwalk_sg_chain(pctx->dst, 2, req->dst);
410                 dst = pctx->dst;
411         }
412 
413         ablkcipher_request_set_tfm(abreq, ctx->ctr);
414         ablkcipher_request_set_callback(abreq, pctx->flags,
415                                         crypto_ccm_decrypt_done, req);
416         ablkcipher_request_set_crypt(abreq, pctx->src, dst, cryptlen + 16, iv);
417         err = crypto_ablkcipher_decrypt(abreq);
418         if (err)
419                 return err;
420 
421         err = crypto_ccm_auth(req, req->dst, cryptlen);
422         if (err)
423                 return err;
424 
425         /* verify */
426         if (crypto_memneq(authtag, odata, authsize))
427                 return -EBADMSG;
428 
429         return err;
430 }
431 
432 static int crypto_ccm_init_tfm(struct crypto_tfm *tfm)
433 {
434         struct crypto_instance *inst = (void *)tfm->__crt_alg;
435         struct ccm_instance_ctx *ictx = crypto_instance_ctx(inst);
436         struct crypto_ccm_ctx *ctx = crypto_tfm_ctx(tfm);
437         struct crypto_cipher *cipher;
438         struct crypto_ablkcipher *ctr;
439         unsigned long align;
440         int err;
441 
442         cipher = crypto_spawn_cipher(&ictx->cipher);
443         if (IS_ERR(cipher))
444                 return PTR_ERR(cipher);
445 
446         ctr = crypto_spawn_skcipher(&ictx->ctr);
447         err = PTR_ERR(ctr);
448         if (IS_ERR(ctr))
449                 goto err_free_cipher;
450 
451         ctx->cipher = cipher;
452         ctx->ctr = ctr;
453 
454         align = crypto_tfm_alg_alignmask(tfm);
455         align &= ~(crypto_tfm_ctx_alignment() - 1);
456         tfm->crt_aead.reqsize = align +
457                                 sizeof(struct crypto_ccm_req_priv_ctx) +
458                                 crypto_ablkcipher_reqsize(ctr);
459 
460         return 0;
461 
462 err_free_cipher:
463         crypto_free_cipher(cipher);
464         return err;
465 }
466 
467 static void crypto_ccm_exit_tfm(struct crypto_tfm *tfm)
468 {
469         struct crypto_ccm_ctx *ctx = crypto_tfm_ctx(tfm);
470 
471         crypto_free_cipher(ctx->cipher);
472         crypto_free_ablkcipher(ctx->ctr);
473 }
474 
475 static struct crypto_instance *crypto_ccm_alloc_common(struct rtattr **tb,
476                                                        const char *full_name,
477                                                        const char *ctr_name,
478                                                        const char *cipher_name)
479 {
480         struct crypto_attr_type *algt;
481         struct crypto_instance *inst;
482         struct crypto_alg *ctr;
483         struct crypto_alg *cipher;
484         struct ccm_instance_ctx *ictx;
485         int err;
486 
487         algt = crypto_get_attr_type(tb);
488         if (IS_ERR(algt))
489                 return ERR_CAST(algt);
490 
491         if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
492                 return ERR_PTR(-EINVAL);
493 
494         cipher = crypto_alg_mod_lookup(cipher_name,  CRYPTO_ALG_TYPE_CIPHER,
495                                        CRYPTO_ALG_TYPE_MASK);
496         if (IS_ERR(cipher))
497                 return ERR_CAST(cipher);
498 
499         err = -EINVAL;
500         if (cipher->cra_blocksize != 16)
501                 goto out_put_cipher;
502 
503         inst = kzalloc(sizeof(*inst) + sizeof(*ictx), GFP_KERNEL);
504         err = -ENOMEM;
505         if (!inst)
506                 goto out_put_cipher;
507 
508         ictx = crypto_instance_ctx(inst);
509 
510         err = crypto_init_spawn(&ictx->cipher, cipher, inst,
511                                 CRYPTO_ALG_TYPE_MASK);
512         if (err)
513                 goto err_free_inst;
514 
515         crypto_set_skcipher_spawn(&ictx->ctr, inst);
516         err = crypto_grab_skcipher(&ictx->ctr, ctr_name, 0,
517                                    crypto_requires_sync(algt->type,
518                                                         algt->mask));
519         if (err)
520                 goto err_drop_cipher;
521 
522         ctr = crypto_skcipher_spawn_alg(&ictx->ctr);
523 
524         /* Not a stream cipher? */
525         err = -EINVAL;
526         if (ctr->cra_blocksize != 1)
527                 goto err_drop_ctr;
528 
529         /* We want the real thing! */
530         if (ctr->cra_ablkcipher.ivsize != 16)
531                 goto err_drop_ctr;
532 
533         err = -ENAMETOOLONG;
534         if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
535                      "ccm_base(%s,%s)", ctr->cra_driver_name,
536                      cipher->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
537                 goto err_drop_ctr;
538 
539         memcpy(inst->alg.cra_name, full_name, CRYPTO_MAX_ALG_NAME);
540 
541         inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD;
542         inst->alg.cra_flags |= ctr->cra_flags & CRYPTO_ALG_ASYNC;
543         inst->alg.cra_priority = cipher->cra_priority + ctr->cra_priority;
544         inst->alg.cra_blocksize = 1;
545         inst->alg.cra_alignmask = cipher->cra_alignmask | ctr->cra_alignmask |
546                                   (__alignof__(u32) - 1);
547         inst->alg.cra_type = &crypto_aead_type;
548         inst->alg.cra_aead.ivsize = 16;
549         inst->alg.cra_aead.maxauthsize = 16;
550         inst->alg.cra_ctxsize = sizeof(struct crypto_ccm_ctx);
551         inst->alg.cra_init = crypto_ccm_init_tfm;
552         inst->alg.cra_exit = crypto_ccm_exit_tfm;
553         inst->alg.cra_aead.setkey = crypto_ccm_setkey;
554         inst->alg.cra_aead.setauthsize = crypto_ccm_setauthsize;
555         inst->alg.cra_aead.encrypt = crypto_ccm_encrypt;
556         inst->alg.cra_aead.decrypt = crypto_ccm_decrypt;
557 
558 out:
559         crypto_mod_put(cipher);
560         return inst;
561 
562 err_drop_ctr:
563         crypto_drop_skcipher(&ictx->ctr);
564 err_drop_cipher:
565         crypto_drop_spawn(&ictx->cipher);
566 err_free_inst:
567         kfree(inst);
568 out_put_cipher:
569         inst = ERR_PTR(err);
570         goto out;
571 }
572 
573 static struct crypto_instance *crypto_ccm_alloc(struct rtattr **tb)
574 {
575         const char *cipher_name;
576         char ctr_name[CRYPTO_MAX_ALG_NAME];
577         char full_name[CRYPTO_MAX_ALG_NAME];
578 
579         cipher_name = crypto_attr_alg_name(tb[1]);
580         if (IS_ERR(cipher_name))
581                 return ERR_CAST(cipher_name);
582 
583         if (snprintf(ctr_name, CRYPTO_MAX_ALG_NAME, "ctr(%s)",
584                      cipher_name) >= CRYPTO_MAX_ALG_NAME)
585                 return ERR_PTR(-ENAMETOOLONG);
586 
587         if (snprintf(full_name, CRYPTO_MAX_ALG_NAME, "ccm(%s)", cipher_name) >=
588             CRYPTO_MAX_ALG_NAME)
589                 return ERR_PTR(-ENAMETOOLONG);
590 
591         return crypto_ccm_alloc_common(tb, full_name, ctr_name, cipher_name);
592 }
593 
594 static void crypto_ccm_free(struct crypto_instance *inst)
595 {
596         struct ccm_instance_ctx *ctx = crypto_instance_ctx(inst);
597 
598         crypto_drop_spawn(&ctx->cipher);
599         crypto_drop_skcipher(&ctx->ctr);
600         kfree(inst);
601 }
602 
603 static struct crypto_template crypto_ccm_tmpl = {
604         .name = "ccm",
605         .alloc = crypto_ccm_alloc,
606         .free = crypto_ccm_free,
607         .module = THIS_MODULE,
608 };
609 
610 static struct crypto_instance *crypto_ccm_base_alloc(struct rtattr **tb)
611 {
612         const char *ctr_name;
613         const char *cipher_name;
614         char full_name[CRYPTO_MAX_ALG_NAME];
615 
616         ctr_name = crypto_attr_alg_name(tb[1]);
617         if (IS_ERR(ctr_name))
618                 return ERR_CAST(ctr_name);
619 
620         cipher_name = crypto_attr_alg_name(tb[2]);
621         if (IS_ERR(cipher_name))
622                 return ERR_CAST(cipher_name);
623 
624         if (snprintf(full_name, CRYPTO_MAX_ALG_NAME, "ccm_base(%s,%s)",
625                      ctr_name, cipher_name) >= CRYPTO_MAX_ALG_NAME)
626                 return ERR_PTR(-ENAMETOOLONG);
627 
628         return crypto_ccm_alloc_common(tb, full_name, ctr_name, cipher_name);
629 }
630 
631 static struct crypto_template crypto_ccm_base_tmpl = {
632         .name = "ccm_base",
633         .alloc = crypto_ccm_base_alloc,
634         .free = crypto_ccm_free,
635         .module = THIS_MODULE,
636 };
637 
638 static int crypto_rfc4309_setkey(struct crypto_aead *parent, const u8 *key,
639                                  unsigned int keylen)
640 {
641         struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(parent);
642         struct crypto_aead *child = ctx->child;
643         int err;
644 
645         if (keylen < 3)
646                 return -EINVAL;
647 
648         keylen -= 3;
649         memcpy(ctx->nonce, key + keylen, 3);
650 
651         crypto_aead_clear_flags(child, CRYPTO_TFM_REQ_MASK);
652         crypto_aead_set_flags(child, crypto_aead_get_flags(parent) &
653                                      CRYPTO_TFM_REQ_MASK);
654         err = crypto_aead_setkey(child, key, keylen);
655         crypto_aead_set_flags(parent, crypto_aead_get_flags(child) &
656                                       CRYPTO_TFM_RES_MASK);
657 
658         return err;
659 }
660 
661 static int crypto_rfc4309_setauthsize(struct crypto_aead *parent,
662                                       unsigned int authsize)
663 {
664         struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(parent);
665 
666         switch (authsize) {
667         case 8:
668         case 12:
669         case 16:
670                 break;
671         default:
672                 return -EINVAL;
673         }
674 
675         return crypto_aead_setauthsize(ctx->child, authsize);
676 }
677 
678 static struct aead_request *crypto_rfc4309_crypt(struct aead_request *req)
679 {
680         struct aead_request *subreq = aead_request_ctx(req);
681         struct crypto_aead *aead = crypto_aead_reqtfm(req);
682         struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(aead);
683         struct crypto_aead *child = ctx->child;
684         u8 *iv = PTR_ALIGN((u8 *)(subreq + 1) + crypto_aead_reqsize(child),
685                            crypto_aead_alignmask(child) + 1);
686 
687         /* L' */
688         iv[0] = 3;
689 
690         memcpy(iv + 1, ctx->nonce, 3);
691         memcpy(iv + 4, req->iv, 8);
692 
693         aead_request_set_tfm(subreq, child);
694         aead_request_set_callback(subreq, req->base.flags, req->base.complete,
695                                   req->base.data);
696         aead_request_set_crypt(subreq, req->src, req->dst, req->cryptlen, iv);
697         aead_request_set_assoc(subreq, req->assoc, req->assoclen);
698 
699         return subreq;
700 }
701 
702 static int crypto_rfc4309_encrypt(struct aead_request *req)
703 {
704         req = crypto_rfc4309_crypt(req);
705 
706         return crypto_aead_encrypt(req);
707 }
708 
709 static int crypto_rfc4309_decrypt(struct aead_request *req)
710 {
711         req = crypto_rfc4309_crypt(req);
712 
713         return crypto_aead_decrypt(req);
714 }
715 
716 static int crypto_rfc4309_init_tfm(struct crypto_tfm *tfm)
717 {
718         struct crypto_instance *inst = (void *)tfm->__crt_alg;
719         struct crypto_aead_spawn *spawn = crypto_instance_ctx(inst);
720         struct crypto_rfc4309_ctx *ctx = crypto_tfm_ctx(tfm);
721         struct crypto_aead *aead;
722         unsigned long align;
723 
724         aead = crypto_spawn_aead(spawn);
725         if (IS_ERR(aead))
726                 return PTR_ERR(aead);
727 
728         ctx->child = aead;
729 
730         align = crypto_aead_alignmask(aead);
731         align &= ~(crypto_tfm_ctx_alignment() - 1);
732         tfm->crt_aead.reqsize = sizeof(struct aead_request) +
733                                 ALIGN(crypto_aead_reqsize(aead),
734                                       crypto_tfm_ctx_alignment()) +
735                                 align + 16;
736 
737         return 0;
738 }
739 
740 static void crypto_rfc4309_exit_tfm(struct crypto_tfm *tfm)
741 {
742         struct crypto_rfc4309_ctx *ctx = crypto_tfm_ctx(tfm);
743 
744         crypto_free_aead(ctx->child);
745 }
746 
747 static struct crypto_instance *crypto_rfc4309_alloc(struct rtattr **tb)
748 {
749         struct crypto_attr_type *algt;
750         struct crypto_instance *inst;
751         struct crypto_aead_spawn *spawn;
752         struct crypto_alg *alg;
753         const char *ccm_name;
754         int err;
755 
756         algt = crypto_get_attr_type(tb);
757         if (IS_ERR(algt))
758                 return ERR_CAST(algt);
759 
760         if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
761                 return ERR_PTR(-EINVAL);
762 
763         ccm_name = crypto_attr_alg_name(tb[1]);
764         if (IS_ERR(ccm_name))
765                 return ERR_CAST(ccm_name);
766 
767         inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
768         if (!inst)
769                 return ERR_PTR(-ENOMEM);
770 
771         spawn = crypto_instance_ctx(inst);
772         crypto_set_aead_spawn(spawn, inst);
773         err = crypto_grab_aead(spawn, ccm_name, 0,
774                                crypto_requires_sync(algt->type, algt->mask));
775         if (err)
776                 goto out_free_inst;
777 
778         alg = crypto_aead_spawn_alg(spawn);
779 
780         err = -EINVAL;
781 
782         /* We only support 16-byte blocks. */
783         if (alg->cra_aead.ivsize != 16)
784                 goto out_drop_alg;
785 
786         /* Not a stream cipher? */
787         if (alg->cra_blocksize != 1)
788                 goto out_drop_alg;
789 
790         err = -ENAMETOOLONG;
791         if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME,
792                      "rfc4309(%s)", alg->cra_name) >= CRYPTO_MAX_ALG_NAME ||
793             snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
794                      "rfc4309(%s)", alg->cra_driver_name) >=
795             CRYPTO_MAX_ALG_NAME)
796                 goto out_drop_alg;
797 
798         inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD;
799         inst->alg.cra_flags |= alg->cra_flags & CRYPTO_ALG_ASYNC;
800         inst->alg.cra_priority = alg->cra_priority;
801         inst->alg.cra_blocksize = 1;
802         inst->alg.cra_alignmask = alg->cra_alignmask;
803         inst->alg.cra_type = &crypto_nivaead_type;
804 
805         inst->alg.cra_aead.ivsize = 8;
806         inst->alg.cra_aead.maxauthsize = 16;
807 
808         inst->alg.cra_ctxsize = sizeof(struct crypto_rfc4309_ctx);
809 
810         inst->alg.cra_init = crypto_rfc4309_init_tfm;
811         inst->alg.cra_exit = crypto_rfc4309_exit_tfm;
812 
813         inst->alg.cra_aead.setkey = crypto_rfc4309_setkey;
814         inst->alg.cra_aead.setauthsize = crypto_rfc4309_setauthsize;
815         inst->alg.cra_aead.encrypt = crypto_rfc4309_encrypt;
816         inst->alg.cra_aead.decrypt = crypto_rfc4309_decrypt;
817 
818         inst->alg.cra_aead.geniv = "seqiv";
819 
820 out:
821         return inst;
822 
823 out_drop_alg:
824         crypto_drop_aead(spawn);
825 out_free_inst:
826         kfree(inst);
827         inst = ERR_PTR(err);
828         goto out;
829 }
830 
831 static void crypto_rfc4309_free(struct crypto_instance *inst)
832 {
833         crypto_drop_spawn(crypto_instance_ctx(inst));
834         kfree(inst);
835 }
836 
837 static struct crypto_template crypto_rfc4309_tmpl = {
838         .name = "rfc4309",
839         .alloc = crypto_rfc4309_alloc,
840         .free = crypto_rfc4309_free,
841         .module = THIS_MODULE,
842 };
843 
844 static int __init crypto_ccm_module_init(void)
845 {
846         int err;
847 
848         err = crypto_register_template(&crypto_ccm_base_tmpl);
849         if (err)
850                 goto out;
851 
852         err = crypto_register_template(&crypto_ccm_tmpl);
853         if (err)
854                 goto out_undo_base;
855 
856         err = crypto_register_template(&crypto_rfc4309_tmpl);
857         if (err)
858                 goto out_undo_ccm;
859 
860 out:
861         return err;
862 
863 out_undo_ccm:
864         crypto_unregister_template(&crypto_ccm_tmpl);
865 out_undo_base:
866         crypto_unregister_template(&crypto_ccm_base_tmpl);
867         goto out;
868 }
869 
870 static void __exit crypto_ccm_module_exit(void)
871 {
872         crypto_unregister_template(&crypto_rfc4309_tmpl);
873         crypto_unregister_template(&crypto_ccm_tmpl);
874         crypto_unregister_template(&crypto_ccm_base_tmpl);
875 }
876 
877 module_init(crypto_ccm_module_init);
878 module_exit(crypto_ccm_module_exit);
879 
880 MODULE_LICENSE("GPL");
881 MODULE_DESCRIPTION("Counter with CBC MAC");
882 MODULE_ALIAS("ccm_base");
883 MODULE_ALIAS("rfc4309");
884 

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