crypto/ccm.c

   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/hash.h>
  15 #include <crypto/internal/skcipher.h>
  16 #include <crypto/scatterwalk.h>
  17 #include <linux/err.h>
  18 #include <linux/init.h>
  19 #include <linux/kernel.h>
  20 #include <linux/module.h>
  21 #include <linux/slab.h>
  22
  23 #include "internal.h"
  24
  25 struct ccm_instance_ctx {
  26         struct crypto_skcipher_spawn ctr;
  27         struct crypto_ahash_spawn mac;
  28 };
  29
  30 struct crypto_ccm_ctx {
  31         struct crypto_ahash *mac;
  32         struct crypto_skcipher *ctr;
  33 };
  34
  35 struct crypto_rfc4309_ctx {
  36         struct crypto_aead *child;
  37         u8 nonce[3];
  38 };
  39
  40 struct crypto_rfc4309_req_ctx {
  41         struct scatterlist src[3];
  42         struct scatterlist dst[3];
  43         struct aead_request subreq;
  44 };
  45
  46 struct crypto_ccm_req_priv_ctx {
  47         u8 odata[16];
  48         u8 idata[16];
  49         u8 auth_tag[16];
  50         u32 flags;
  51         struct scatterlist src[3];
  52         struct scatterlist dst[3];
  53         union {
  54                 struct ahash_request ahreq;
  55                 struct skcipher_request skreq;
  56         };
  57 };
  58
  59 struct cbcmac_tfm_ctx {
  60         struct crypto_cipher *child;
  61 };
  62
  63 struct cbcmac_desc_ctx {
  64         unsigned int len;
  65 };
  66
  67 static inline struct crypto_ccm_req_priv_ctx *crypto_ccm_reqctx(
  68         struct aead_request *req)
  69 {
  70         unsigned long align = crypto_aead_alignmask(crypto_aead_reqtfm(req));
  71
  72         return (void *)PTR_ALIGN((u8 *)aead_request_ctx(req), align + 1);
  73 }
  74
  75 static int set_msg_len(u8 *block, unsigned int msglen, int csize)
  76 {
  77         __be32 data;
  78
  79         memset(block, 0, csize);
  80         block += csize;
  81
  82         if (csize >= 4)
  83                 csize = 4;
  84         else if (msglen > (1 << (8 * csize)))
  85                 return -EOVERFLOW;
  86
  87         data = cpu_to_be32(msglen);
  88         memcpy(block - csize, (u8 *)&data + 4 - csize, csize);
  89
  90         return 0;
  91 }
  92
  93 static int crypto_ccm_setkey(struct crypto_aead *aead, const u8 *key,
  94                              unsigned int keylen)
  95 {
  96         struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
  97         struct crypto_skcipher *ctr = ctx->ctr;
  98         struct crypto_ahash *mac = ctx->mac;
  99         int err = 0;
 100
 101         crypto_skcipher_clear_flags(ctr, CRYPTO_TFM_REQ_MASK);
 102         crypto_skcipher_set_flags(ctr, crypto_aead_get_flags(aead) &
 103                                        CRYPTO_TFM_REQ_MASK);
 104         err = crypto_skcipher_setkey(ctr, key, keylen);
 105         crypto_aead_set_flags(aead, crypto_skcipher_get_flags(ctr) &
 106                               CRYPTO_TFM_RES_MASK);
 107         if (err)
 108                 goto out;
 109
 110         crypto_ahash_clear_flags(mac, CRYPTO_TFM_REQ_MASK);
 111         crypto_ahash_set_flags(mac, crypto_aead_get_flags(aead) &
 112                                     CRYPTO_TFM_REQ_MASK);
 113         err = crypto_ahash_setkey(mac, key, keylen);
 114         crypto_aead_set_flags(aead, crypto_ahash_get_flags(mac) &
 115                               CRYPTO_TFM_RES_MASK);
 116
 117 out:
 118         return err;
 119 }
 120
 121 static int crypto_ccm_setauthsize(struct crypto_aead *tfm,
 122                                   unsigned int authsize)
 123 {
 124         switch (authsize) {
 125         case 4:
 126         case 6:
 127         case 8:
 128         case 10:
 129         case 12:
 130         case 14:
 131         case 16:
 132                 break;
 133         default:
 134                 return -EINVAL;
 135         }
 136
 137         return 0;
 138 }
 139
 140 static int format_input(u8 *info, struct aead_request *req,
 141                         unsigned int cryptlen)
 142 {
 143         struct crypto_aead *aead = crypto_aead_reqtfm(req);
 144         unsigned int lp = req->iv[0];
 145         unsigned int l = lp + 1;
 146         unsigned int m;
 147
 148         m = crypto_aead_authsize(aead);
 149
 150         memcpy(info, req->iv, 16);
 151
 152         /* format control info per RFC 3610 and
 153          * NIST Special Publication 800-38C
 154          */
 155         *info |= (8 * ((m - 2) / 2));
 156         if (req->assoclen)
 157                 *info |= 64;
 158
 159         return set_msg_len(info + 16 - l, cryptlen, l);
 160 }
 161
 162 static int format_adata(u8 *adata, unsigned int a)
 163 {
 164         int len = 0;
 165
 166         /* add control info for associated data
 167          * RFC 3610 and NIST Special Publication 800-38C
 168          */
 169         if (a < 65280) {
 170                 *(__be16 *)adata = cpu_to_be16(a);
 171                 len = 2;
 172         } else  {
 173                 *(__be16 *)adata = cpu_to_be16(0xfffe);
 174                 *(__be32 *)&adata[2] = cpu_to_be32(a);
 175                 len = 6;
 176         }
 177
 178         return len;
 179 }
 180
 181 static int crypto_ccm_auth(struct aead_request *req, struct scatterlist *plain,
 182                            unsigned int cryptlen)
 183 {
 184         struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
 185         struct crypto_aead *aead = crypto_aead_reqtfm(req);
 186         struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
 187         struct ahash_request *ahreq = &pctx->ahreq;
 188         unsigned int assoclen = req->assoclen;
 189         struct scatterlist sg[3];
 190         u8 *odata = pctx->odata;
 191         u8 *idata = pctx->idata;
 192         int ilen, err;
 193
 194         /* format control data for input */
 195         err = format_input(odata, req, cryptlen);
 196         if (err)
 197                 goto out;
 198
 199         sg_init_table(sg, 3);
 200         sg_set_buf(&sg[0], odata, 16);
 201
 202         /* format associated data and compute into mac */
 203         if (assoclen) {
 204                 ilen = format_adata(idata, assoclen);
 205                 sg_set_buf(&sg[1], idata, ilen);
 206                 sg_chain(sg, 3, req->src);
 207         } else {
 208                 ilen = 0;
 209                 sg_chain(sg, 2, req->src);
 210         }
 211
 212         ahash_request_set_tfm(ahreq, ctx->mac);
 213         ahash_request_set_callback(ahreq, pctx->flags, NULL, NULL);
 214         ahash_request_set_crypt(ahreq, sg, NULL, assoclen + ilen + 16);
 215         err = crypto_ahash_init(ahreq);
 216         if (err)
 217                 goto out;
 218         err = crypto_ahash_update(ahreq);
 219         if (err)
 220                 goto out;
 221
 222         /* we need to pad the MAC input to a round multiple of the block size */
 223         ilen = 16 - (assoclen + ilen) % 16;
 224         if (ilen < 16) {
 225                 memset(idata, 0, ilen);
 226                 sg_init_table(sg, 2);
 227                 sg_set_buf(&sg[0], idata, ilen);
 228                 if (plain)
 229                         sg_chain(sg, 2, plain);
 230                 plain = sg;
 231                 cryptlen += ilen;
 232         }
 233
 234         ahash_request_set_crypt(ahreq, plain, pctx->odata, cryptlen);
 235         err = crypto_ahash_finup(ahreq);
 236 out:
 237         return err;
 238 }
 239
 240 static void crypto_ccm_encrypt_done(struct crypto_async_request *areq, int err)
 241 {
 242         struct aead_request *req = areq->data;
 243         struct crypto_aead *aead = crypto_aead_reqtfm(req);
 244         struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
 245         u8 *odata = pctx->odata;
 246
 247         if (!err)
 248                 scatterwalk_map_and_copy(odata, req->dst,
 249                                          req->assoclen + req->cryptlen,
 250                                          crypto_aead_authsize(aead), 1);
 251         aead_request_complete(req, err);
 252 }
 253
 254 static inline int crypto_ccm_check_iv(const u8 *iv)
 255 {
 256         /* 2 <= L <= 8, so 1 <= L' <= 7. */
 257         if (1 > iv[0] || iv[0] > 7)
 258                 return -EINVAL;
 259
 260         return 0;
 261 }
 262
 263 static int crypto_ccm_init_crypt(struct aead_request *req, u8 *tag)
 264 {
 265         struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
 266         struct scatterlist *sg;
 267         u8 *iv = req->iv;
 268         int err;
 269
 270         err = crypto_ccm_check_iv(iv);
 271         if (err)
 272                 return err;
 273
 274         pctx->flags = aead_request_flags(req);
 275
 276          /* Note: rfc 3610 and NIST 800-38C require counter of
 277          * zero to encrypt auth tag.
 278          */
 279         memset(iv + 15 - iv[0], 0, iv[0] + 1);
 280
 281         sg_init_table(pctx->src, 3);
 282         sg_set_buf(pctx->src, tag, 16);
 283         sg = scatterwalk_ffwd(pctx->src + 1, req->src, req->assoclen);
 284         if (sg != pctx->src + 1)
 285                 sg_chain(pctx->src, 2, sg);
 286
 287         if (req->src != req->dst) {
 288                 sg_init_table(pctx->dst, 3);
 289                 sg_set_buf(pctx->dst, tag, 16);
 290                 sg = scatterwalk_ffwd(pctx->dst + 1, req->dst, req->assoclen);
 291                 if (sg != pctx->dst + 1)
 292                         sg_chain(pctx->dst, 2, sg);
 293         }
 294
 295         return 0;
 296 }
 297
 298 static int crypto_ccm_encrypt(struct aead_request *req)
 299 {
 300         struct crypto_aead *aead = crypto_aead_reqtfm(req);
 301         struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
 302         struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
 303         struct skcipher_request *skreq = &pctx->skreq;
 304         struct scatterlist *dst;
 305         unsigned int cryptlen = req->cryptlen;
 306         u8 *odata = pctx->odata;
 307         u8 *iv = req->iv;
 308         int err;
 309
 310         err = crypto_ccm_init_crypt(req, odata);
 311         if (err)
 312                 return err;
 313
 314         err = crypto_ccm_auth(req, sg_next(pctx->src), cryptlen);
 315         if (err)
 316                 return err;
 317
 318         dst = pctx->src;
 319         if (req->src != req->dst)
 320                 dst = pctx->dst;
 321
 322         skcipher_request_set_tfm(skreq, ctx->ctr);
 323         skcipher_request_set_callback(skreq, pctx->flags,
 324                                       crypto_ccm_encrypt_done, req);
 325         skcipher_request_set_crypt(skreq, pctx->src, dst, cryptlen + 16, iv);
 326         err = crypto_skcipher_encrypt(skreq);
 327         if (err)
 328                 return err;
 329
 330         /* copy authtag to end of dst */
 331         scatterwalk_map_and_copy(odata, sg_next(dst), cryptlen,
 332                                  crypto_aead_authsize(aead), 1);
 333         return err;
 334 }
 335
 336 static void crypto_ccm_decrypt_done(struct crypto_async_request *areq,
 337                                    int err)
 338 {
 339         struct aead_request *req = areq->data;
 340         struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
 341         struct crypto_aead *aead = crypto_aead_reqtfm(req);
 342         unsigned int authsize = crypto_aead_authsize(aead);
 343         unsigned int cryptlen = req->cryptlen - authsize;
 344         struct scatterlist *dst;
 345
 346         pctx->flags = 0;
 347
 348         dst = sg_next(req->src == req->dst ? pctx->src : pctx->dst);
 349
 350         if (!err) {
 351                 err = crypto_ccm_auth(req, dst, cryptlen);
 352                 if (!err && crypto_memneq(pctx->auth_tag, pctx->odata, authsize))
 353                         err = -EBADMSG;
 354         }
 355         aead_request_complete(req, err);
 356 }
 357
 358 static int crypto_ccm_decrypt(struct aead_request *req)
 359 {
 360         struct crypto_aead *aead = crypto_aead_reqtfm(req);
 361         struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
 362         struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
 363         struct skcipher_request *skreq = &pctx->skreq;
 364         struct scatterlist *dst;
 365         unsigned int authsize = crypto_aead_authsize(aead);
 366         unsigned int cryptlen = req->cryptlen;
 367         u8 *authtag = pctx->auth_tag;
 368         u8 *odata = pctx->odata;
 369         u8 *iv = pctx->idata;
 370         int err;
 371
 372         cryptlen -= authsize;
 373
 374         err = crypto_ccm_init_crypt(req, authtag);
 375         if (err)
 376                 return err;
 377
 378         scatterwalk_map_and_copy(authtag, sg_next(pctx->src), cryptlen,
 379                                  authsize, 0);
 380
 381         dst = pctx->src;
 382         if (req->src != req->dst)
 383                 dst = pctx->dst;
 384
 385         memcpy(iv, req->iv, 16);
 386
 387         skcipher_request_set_tfm(skreq, ctx->ctr);
 388         skcipher_request_set_callback(skreq, pctx->flags,
 389                                       crypto_ccm_decrypt_done, req);
 390         skcipher_request_set_crypt(skreq, pctx->src, dst, cryptlen + 16, iv);
 391         err = crypto_skcipher_decrypt(skreq);
 392         if (err)
 393                 return err;
 394
 395         err = crypto_ccm_auth(req, sg_next(dst), cryptlen);
 396         if (err)
 397                 return err;
 398
 399         /* verify */
 400         if (crypto_memneq(authtag, odata, authsize))
 401                 return -EBADMSG;
 402
 403         return err;
 404 }
 405
 406 static int crypto_ccm_init_tfm(struct crypto_aead *tfm)
 407 {
 408         struct aead_instance *inst = aead_alg_instance(tfm);
 409         struct ccm_instance_ctx *ictx = aead_instance_ctx(inst);
 410         struct crypto_ccm_ctx *ctx = crypto_aead_ctx(tfm);
 411         struct crypto_ahash *mac;
 412         struct crypto_skcipher *ctr;
 413         unsigned long align;
 414         int err;
 415
 416         mac = crypto_spawn_ahash(&ictx->mac);
 417         if (IS_ERR(mac))
 418                 return PTR_ERR(mac);
 419
 420         ctr = crypto_spawn_skcipher(&ictx->ctr);
 421         err = PTR_ERR(ctr);
 422         if (IS_ERR(ctr))
 423                 goto err_free_mac;
 424
 425         ctx->mac = mac;
 426         ctx->ctr = ctr;
 427
 428         align = crypto_aead_alignmask(tfm);
 429         align &= ~(crypto_tfm_ctx_alignment() - 1);
 430         crypto_aead_set_reqsize(
 431                 tfm,
 432                 align + sizeof(struct crypto_ccm_req_priv_ctx) +
 433                 max(crypto_ahash_reqsize(mac), crypto_skcipher_reqsize(ctr)));
 434
 435         return 0;
 436
 437 err_free_mac:
 438         crypto_free_ahash(mac);
 439         return err;
 440 }
 441
 442 static void crypto_ccm_exit_tfm(struct crypto_aead *tfm)
 443 {
 444         struct crypto_ccm_ctx *ctx = crypto_aead_ctx(tfm);
 445
 446         crypto_free_ahash(ctx->mac);
 447         crypto_free_skcipher(ctx->ctr);
 448 }
 449
 450 static void crypto_ccm_free(struct aead_instance *inst)
 451 {
 452         struct ccm_instance_ctx *ctx = aead_instance_ctx(inst);
 453
 454         crypto_drop_ahash(&ctx->mac);
 455         crypto_drop_skcipher(&ctx->ctr);
 456         kfree(inst);
 457 }
 458
 459 static int crypto_ccm_create_common(struct crypto_template *tmpl,
 460                                     struct rtattr **tb,
 461                                     const char *ctr_name,
 462                                     const char *mac_name)
 463 {
 464         struct crypto_attr_type *algt;
 465         struct aead_instance *inst;
 466         struct skcipher_alg *ctr;
 467         struct crypto_alg *mac_alg;
 468         struct hash_alg_common *mac;
 469         struct ccm_instance_ctx *ictx;
 470         int err;
 471
 472         algt = crypto_get_attr_type(tb);
 473         if (IS_ERR(algt))
 474                 return PTR_ERR(algt);
 475
 476         if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
 477                 return -EINVAL;
 478
 479         mac_alg = crypto_find_alg(mac_name, &crypto_ahash_type,
 480                                   CRYPTO_ALG_TYPE_HASH,
 481                                   CRYPTO_ALG_TYPE_AHASH_MASK |
 482                                   CRYPTO_ALG_ASYNC);
 483         if (IS_ERR(mac_alg))
 484                 return PTR_ERR(mac_alg);
 485
 486         mac = __crypto_hash_alg_common(mac_alg);
 487         err = -EINVAL;
 488         if (strncmp(mac->base.cra_name, "cbcmac(", 7) != 0 ||
 489             mac->digestsize != 16)
 490                 goto out_put_mac;
 491
 492         inst = kzalloc(sizeof(*inst) + sizeof(*ictx), GFP_KERNEL);
 493         err = -ENOMEM;
 494         if (!inst)
 495                 goto out_put_mac;
 496
 497         ictx = aead_instance_ctx(inst);
 498         err = crypto_init_ahash_spawn(&ictx->mac, mac,
 499                                       aead_crypto_instance(inst));
 500         if (err)
 501                 goto err_free_inst;
 502
 503         crypto_set_skcipher_spawn(&ictx->ctr, aead_crypto_instance(inst));
 504         err = crypto_grab_skcipher(&ictx->ctr, ctr_name, 0,
 505                                    crypto_requires_sync(algt->type,
 506                                                         algt->mask));
 507         if (err)
 508                 goto err_drop_mac;
 509
 510         ctr = crypto_spawn_skcipher_alg(&ictx->ctr);
 511
 512         /* The skcipher algorithm must be CTR mode, using 16-byte blocks. */
 513         err = -EINVAL;
 514         if (strncmp(ctr->base.cra_name, "ctr(", 4) != 0 ||
 515             crypto_skcipher_alg_ivsize(ctr) != 16 ||
 516             ctr->base.cra_blocksize != 1)
 517                 goto err_drop_ctr;
 518
 519         /* ctr and cbcmac must use the same underlying block cipher. */
 520         if (strcmp(ctr->base.cra_name + 4, mac->base.cra_name + 7) != 0)
 521                 goto err_drop_ctr;
 522
 523         err = -ENAMETOOLONG;
 524         if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
 525                      "ccm(%s", ctr->base.cra_name + 4) >= CRYPTO_MAX_ALG_NAME)
 526                 goto err_drop_ctr;
 527
 528         if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
 529                      "ccm_base(%s,%s)", ctr->base.cra_driver_name,
 530                      mac->base.cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
 531                 goto err_drop_ctr;
 532
 533         inst->alg.base.cra_flags = ctr->base.cra_flags & CRYPTO_ALG_ASYNC;
 534         inst->alg.base.cra_priority = (mac->base.cra_priority +
 535                                        ctr->base.cra_priority) / 2;
 536         inst->alg.base.cra_blocksize = 1;
 537         inst->alg.base.cra_alignmask = mac->base.cra_alignmask |
 538                                        ctr->base.cra_alignmask;
 539         inst->alg.ivsize = 16;
 540         inst->alg.chunksize = crypto_skcipher_alg_chunksize(ctr);
 541         inst->alg.maxauthsize = 16;
 542         inst->alg.base.cra_ctxsize = sizeof(struct crypto_ccm_ctx);
 543         inst->alg.init = crypto_ccm_init_tfm;
 544         inst->alg.exit = crypto_ccm_exit_tfm;
 545         inst->alg.setkey = crypto_ccm_setkey;
 546         inst->alg.setauthsize = crypto_ccm_setauthsize;
 547         inst->alg.encrypt = crypto_ccm_encrypt;
 548         inst->alg.decrypt = crypto_ccm_decrypt;
 549
 550         inst->free = crypto_ccm_free;
 551
 552         err = aead_register_instance(tmpl, inst);
 553         if (err)
 554                 goto err_drop_ctr;
 555
 556 out_put_mac:
 557         crypto_mod_put(mac_alg);
 558         return err;
 559
 560 err_drop_ctr:
 561         crypto_drop_skcipher(&ictx->ctr);
 562 err_drop_mac:
 563         crypto_drop_ahash(&ictx->mac);
 564 err_free_inst:
 565         kfree(inst);
 566         goto out_put_mac;
 567 }
 568
 569 static int crypto_ccm_create(struct crypto_template *tmpl, struct rtattr **tb)
 570 {
 571         const char *cipher_name;
 572         char ctr_name[CRYPTO_MAX_ALG_NAME];
 573         char mac_name[CRYPTO_MAX_ALG_NAME];
 574
 575         cipher_name = crypto_attr_alg_name(tb[1]);
 576         if (IS_ERR(cipher_name))
 577                 return PTR_ERR(cipher_name);
 578
 579         if (snprintf(ctr_name, CRYPTO_MAX_ALG_NAME, "ctr(%s)",
 580                      cipher_name) >= CRYPTO_MAX_ALG_NAME)
 581                 return -ENAMETOOLONG;
 582
 583         if (snprintf(mac_name, CRYPTO_MAX_ALG_NAME, "cbcmac(%s)",
 584                      cipher_name) >= CRYPTO_MAX_ALG_NAME)
 585                 return -ENAMETOOLONG;
 586
 587         return crypto_ccm_create_common(tmpl, tb, ctr_name, mac_name);
 588 }
 589
 590 static int crypto_ccm_base_create(struct crypto_template *tmpl,
 591                                   struct rtattr **tb)
 592 {
 593         const char *ctr_name;
 594         const char *mac_name;
 595
 596         ctr_name = crypto_attr_alg_name(tb[1]);
 597         if (IS_ERR(ctr_name))
 598                 return PTR_ERR(ctr_name);
 599
 600         mac_name = crypto_attr_alg_name(tb[2]);
 601         if (IS_ERR(mac_name))
 602                 return PTR_ERR(mac_name);
 603
 604         return crypto_ccm_create_common(tmpl, tb, ctr_name, mac_name);
 605 }
 606
 607 static int crypto_rfc4309_setkey(struct crypto_aead *parent, const u8 *key,
 608                                  unsigned int keylen)
 609 {
 610         struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(parent);
 611         struct crypto_aead *child = ctx->child;
 612         int err;
 613
 614         if (keylen < 3)
 615                 return -EINVAL;
 616
 617         keylen -= 3;
 618         memcpy(ctx->nonce, key + keylen, 3);
 619
 620         crypto_aead_clear_flags(child, CRYPTO_TFM_REQ_MASK);
 621         crypto_aead_set_flags(child, crypto_aead_get_flags(parent) &
 622                                      CRYPTO_TFM_REQ_MASK);
 623         err = crypto_aead_setkey(child, key, keylen);
 624         crypto_aead_set_flags(parent, crypto_aead_get_flags(child) &
 625                                       CRYPTO_TFM_RES_MASK);
 626
 627         return err;
 628 }
 629
 630 static int crypto_rfc4309_setauthsize(struct crypto_aead *parent,
 631                                       unsigned int authsize)
 632 {
 633         struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(parent);
 634
 635         switch (authsize) {
 636         case 8:
 637         case 12:
 638         case 16:
 639                 break;
 640         default:
 641                 return -EINVAL;
 642         }
 643
 644         return crypto_aead_setauthsize(ctx->child, authsize);
 645 }
 646
 647 static struct aead_request *crypto_rfc4309_crypt(struct aead_request *req)
 648 {
 649         struct crypto_rfc4309_req_ctx *rctx = aead_request_ctx(req);
 650         struct aead_request *subreq = &rctx->subreq;
 651         struct crypto_aead *aead = crypto_aead_reqtfm(req);
 652         struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(aead);
 653         struct crypto_aead *child = ctx->child;
 654         struct scatterlist *sg;
 655         u8 *iv = PTR_ALIGN((u8 *)(subreq + 1) + crypto_aead_reqsize(child),
 656                            crypto_aead_alignmask(child) + 1);
 657
 658         /* L' */
 659         iv[0] = 3;
 660
 661         memcpy(iv + 1, ctx->nonce, 3);
 662         memcpy(iv + 4, req->iv, 8);
 663
 664         scatterwalk_map_and_copy(iv + 16, req->src, 0, req->assoclen - 8, 0);
 665
 666         sg_init_table(rctx->src, 3);
 667         sg_set_buf(rctx->src, iv + 16, req->assoclen - 8);
 668         sg = scatterwalk_ffwd(rctx->src + 1, req->src, req->assoclen);
 669         if (sg != rctx->src + 1)
 670                 sg_chain(rctx->src, 2, sg);
 671
 672         if (req->src != req->dst) {
 673                 sg_init_table(rctx->dst, 3);
 674                 sg_set_buf(rctx->dst, iv + 16, req->assoclen - 8);
 675                 sg = scatterwalk_ffwd(rctx->dst + 1, req->dst, req->assoclen);
 676                 if (sg != rctx->dst + 1)
 677                         sg_chain(rctx->dst, 2, sg);
 678         }
 679
 680         aead_request_set_tfm(subreq, child);
 681         aead_request_set_callback(subreq, req->base.flags, req->base.complete,
 682                                   req->base.data);
 683         aead_request_set_crypt(subreq, rctx->src,
 684                                req->src == req->dst ? rctx->src : rctx->dst,
 685                                req->cryptlen, iv);
 686         aead_request_set_ad(subreq, req->assoclen - 8);
 687
 688         return subreq;
 689 }
 690
 691 static int crypto_rfc4309_encrypt(struct aead_request *req)
 692 {
 693         if (req->assoclen != 16 && req->assoclen != 20)
 694                 return -EINVAL;
 695
 696         req = crypto_rfc4309_crypt(req);
 697
 698         return crypto_aead_encrypt(req);
 699 }
 700
 701 static int crypto_rfc4309_decrypt(struct aead_request *req)
 702 {
 703         if (req->assoclen != 16 && req->assoclen != 20)
 704                 return -EINVAL;
 705
 706         req = crypto_rfc4309_crypt(req);
 707
 708         return crypto_aead_decrypt(req);
 709 }
 710
 711 static int crypto_rfc4309_init_tfm(struct crypto_aead *tfm)
 712 {
 713         struct aead_instance *inst = aead_alg_instance(tfm);
 714         struct crypto_aead_spawn *spawn = aead_instance_ctx(inst);
 715         struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(tfm);
 716         struct crypto_aead *aead;
 717         unsigned long align;
 718
 719         aead = crypto_spawn_aead(spawn);
 720         if (IS_ERR(aead))
 721                 return PTR_ERR(aead);
 722
 723         ctx->child = aead;
 724
 725         align = crypto_aead_alignmask(aead);
 726         align &= ~(crypto_tfm_ctx_alignment() - 1);
 727         crypto_aead_set_reqsize(
 728                 tfm,
 729                 sizeof(struct crypto_rfc4309_req_ctx) +
 730                 ALIGN(crypto_aead_reqsize(aead), crypto_tfm_ctx_alignment()) +
 731                 align + 32);
 732
 733         return 0;
 734 }
 735
 736 static void crypto_rfc4309_exit_tfm(struct crypto_aead *tfm)
 737 {
 738         struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(tfm);
 739
 740         crypto_free_aead(ctx->child);
 741 }
 742
 743 static void crypto_rfc4309_free(struct aead_instance *inst)
 744 {
 745         crypto_drop_aead(aead_instance_ctx(inst));
 746         kfree(inst);
 747 }
 748
 749 static int crypto_rfc4309_create(struct crypto_template *tmpl,
 750                                  struct rtattr **tb)
 751 {
 752         struct crypto_attr_type *algt;
 753         struct aead_instance *inst;
 754         struct crypto_aead_spawn *spawn;
 755         struct aead_alg *alg;
 756         const char *ccm_name;
 757         int err;
 758
 759         algt = crypto_get_attr_type(tb);
 760         if (IS_ERR(algt))
 761                 return PTR_ERR(algt);
 762
 763         if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
 764                 return -EINVAL;
 765
 766         ccm_name = crypto_attr_alg_name(tb[1]);
 767         if (IS_ERR(ccm_name))
 768                 return PTR_ERR(ccm_name);
 769
 770         inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
 771         if (!inst)
 772                 return -ENOMEM;
 773
 774         spawn = aead_instance_ctx(inst);
 775         crypto_set_aead_spawn(spawn, aead_crypto_instance(inst));
 776         err = crypto_grab_aead(spawn, ccm_name, 0,
 777                                crypto_requires_sync(algt->type, algt->mask));
 778         if (err)
 779                 goto out_free_inst;
 780
 781         alg = crypto_spawn_aead_alg(spawn);
 782
 783         err = -EINVAL;
 784
 785         /* We only support 16-byte blocks. */
 786         if (crypto_aead_alg_ivsize(alg) != 16)
 787                 goto out_drop_alg;
 788
 789         /* Not a stream cipher? */
 790         if (alg->base.cra_blocksize != 1)
 791                 goto out_drop_alg;
 792
 793         err = -ENAMETOOLONG;
 794         if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
 795                      "rfc4309(%s)", alg->base.cra_name) >=
 796             CRYPTO_MAX_ALG_NAME ||
 797             snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
 798                      "rfc4309(%s)", alg->base.cra_driver_name) >=
 799             CRYPTO_MAX_ALG_NAME)
 800                 goto out_drop_alg;
 801
 802         inst->alg.base.cra_flags = alg->base.cra_flags & CRYPTO_ALG_ASYNC;
 803         inst->alg.base.cra_priority = alg->base.cra_priority;
 804         inst->alg.base.cra_blocksize = 1;
 805         inst->alg.base.cra_alignmask = alg->base.cra_alignmask;
 806
 807         inst->alg.ivsize = 8;
 808         inst->alg.chunksize = crypto_aead_alg_chunksize(alg);
 809         inst->alg.maxauthsize = 16;
 810
 811         inst->alg.base.cra_ctxsize = sizeof(struct crypto_rfc4309_ctx);
 812
 813         inst->alg.init = crypto_rfc4309_init_tfm;
 814         inst->alg.exit = crypto_rfc4309_exit_tfm;
 815
 816         inst->alg.setkey = crypto_rfc4309_setkey;
 817         inst->alg.setauthsize = crypto_rfc4309_setauthsize;
 818         inst->alg.encrypt = crypto_rfc4309_encrypt;
 819         inst->alg.decrypt = crypto_rfc4309_decrypt;
 820
 821         inst->free = crypto_rfc4309_free;
 822
 823         err = aead_register_instance(tmpl, inst);
 824         if (err)
 825                 goto out_drop_alg;
 826
 827 out:
 828         return err;
 829
 830 out_drop_alg:
 831         crypto_drop_aead(spawn);
 832 out_free_inst:
 833         kfree(inst);
 834         goto out;
 835 }
 836
 837 static int crypto_cbcmac_digest_setkey(struct crypto_shash *parent,
 838                                      const u8 *inkey, unsigned int keylen)
 839 {
 840         struct cbcmac_tfm_ctx *ctx = crypto_shash_ctx(parent);
 841
 842         return crypto_cipher_setkey(ctx->child, inkey, keylen);
 843 }
 844
 845 static int crypto_cbcmac_digest_init(struct shash_desc *pdesc)
 846 {
 847         struct cbcmac_desc_ctx *ctx = shash_desc_ctx(pdesc);
 848         int bs = crypto_shash_digestsize(pdesc->tfm);
 849         u8 *dg = (u8 *)ctx + crypto_shash_descsize(pdesc->tfm) - bs;
 850
 851         ctx->len = 0;
 852         memset(dg, 0, bs);
 853
 854         return 0;
 855 }
 856
 857 static int crypto_cbcmac_digest_update(struct shash_desc *pdesc, const u8 *p,
 858                                        unsigned int len)
 859 {
 860         struct crypto_shash *parent = pdesc->tfm;
 861         struct cbcmac_tfm_ctx *tctx = crypto_shash_ctx(parent);
 862         struct cbcmac_desc_ctx *ctx = shash_desc_ctx(pdesc);
 863         struct crypto_cipher *tfm = tctx->child;
 864         int bs = crypto_shash_digestsize(parent);
 865         u8 *dg = (u8 *)ctx + crypto_shash_descsize(parent) - bs;
 866
 867         while (len > 0) {
 868                 unsigned int l = min(len, bs - ctx->len);
 869
 870                 crypto_xor(dg + ctx->len, p, l);
 871                 ctx->len +=l;
 872                 len -= l;
 873                 p += l;
 874
 875                 if (ctx->len == bs) {
 876                         crypto_cipher_encrypt_one(tfm, dg, dg);
 877                         ctx->len = 0;
 878                 }
 879         }
 880
 881         return 0;
 882 }
 883
 884 static int crypto_cbcmac_digest_final(struct shash_desc *pdesc, u8 *out)
 885 {
 886         struct crypto_shash *parent = pdesc->tfm;
 887         struct cbcmac_tfm_ctx *tctx = crypto_shash_ctx(parent);
 888         struct cbcmac_desc_ctx *ctx = shash_desc_ctx(pdesc);
 889         struct crypto_cipher *tfm = tctx->child;
 890         int bs = crypto_shash_digestsize(parent);
 891         u8 *dg = (u8 *)ctx + crypto_shash_descsize(parent) - bs;
 892
 893         if (ctx->len)
 894                 crypto_cipher_encrypt_one(tfm, dg, dg);
 895
 896         memcpy(out, dg, bs);
 897         return 0;
 898 }
 899
 900 static int cbcmac_init_tfm(struct crypto_tfm *tfm)
 901 {
 902         struct crypto_cipher *cipher;
 903         struct crypto_instance *inst = (void *)tfm->__crt_alg;
 904         struct crypto_spawn *spawn = crypto_instance_ctx(inst);
 905         struct cbcmac_tfm_ctx *ctx = crypto_tfm_ctx(tfm);
 906
 907         cipher = crypto_spawn_cipher(spawn);
 908         if (IS_ERR(cipher))
 909                 return PTR_ERR(cipher);
 910
 911         ctx->child = cipher;
 912
 913         return 0;
 914 };
 915
 916 static void cbcmac_exit_tfm(struct crypto_tfm *tfm)
 917 {
 918         struct cbcmac_tfm_ctx *ctx = crypto_tfm_ctx(tfm);
 919         crypto_free_cipher(ctx->child);
 920 }
 921
 922 static int cbcmac_create(struct crypto_template *tmpl, struct rtattr **tb)
 923 {
 924         struct shash_instance *inst;
 925         struct crypto_alg *alg;
 926         int err;
 927
 928         err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SHASH);
 929         if (err)
 930                 return err;
 931
 932         alg = crypto_get_attr_alg(tb, CRYPTO_ALG_TYPE_CIPHER,
 933                                   CRYPTO_ALG_TYPE_MASK);
 934         if (IS_ERR(alg))
 935                 return PTR_ERR(alg);
 936
 937         inst = shash_alloc_instance("cbcmac", alg);
 938         err = PTR_ERR(inst);
 939         if (IS_ERR(inst))
 940                 goto out_put_alg;
 941
 942         err = crypto_init_spawn(shash_instance_ctx(inst), alg,
 943                                 shash_crypto_instance(inst),
 944                                 CRYPTO_ALG_TYPE_MASK);
 945         if (err)
 946                 goto out_free_inst;
 947
 948         inst->alg.base.cra_priority = alg->cra_priority;
 949         inst->alg.base.cra_blocksize = 1;
 950
 951         inst->alg.digestsize = alg->cra_blocksize;
 952         inst->alg.descsize = ALIGN(sizeof(struct cbcmac_desc_ctx),
 953                                    alg->cra_alignmask + 1) +
 954                              alg->cra_blocksize;
 955
 956         inst->alg.base.cra_ctxsize = sizeof(struct cbcmac_tfm_ctx);
 957         inst->alg.base.cra_init = cbcmac_init_tfm;
 958         inst->alg.base.cra_exit = cbcmac_exit_tfm;
 959
 960         inst->alg.init = crypto_cbcmac_digest_init;
 961         inst->alg.update = crypto_cbcmac_digest_update;
 962         inst->alg.final = crypto_cbcmac_digest_final;
 963         inst->alg.setkey = crypto_cbcmac_digest_setkey;
 964
 965         err = shash_register_instance(tmpl, inst);
 966
 967 out_free_inst:
 968         if (err)
 969                 shash_free_instance(shash_crypto_instance(inst));
 970
 971 out_put_alg:
 972         crypto_mod_put(alg);
 973         return err;
 974 }
 975
 976 static struct crypto_template crypto_ccm_tmpls[] = {
 977         {
 978                 .name = "cbcmac",
 979                 .create = cbcmac_create,
 980                 .free = shash_free_instance,
 981                 .module = THIS_MODULE,
 982         }, {
 983                 .name = "ccm_base",
 984                 .create = crypto_ccm_base_create,
 985                 .module = THIS_MODULE,
 986         }, {
 987                 .name = "ccm",
 988                 .create = crypto_ccm_create,
 989                 .module = THIS_MODULE,
 990         }, {
 991                 .name = "rfc4309",
 992                 .create = crypto_rfc4309_create,
 993                 .module = THIS_MODULE,
 994         },
 995 };
 996
 997 static int __init crypto_ccm_module_init(void)
 998 {
 999         return crypto_register_templates(crypto_ccm_tmpls,
1000                                          ARRAY_SIZE(crypto_ccm_tmpls));
1001 }
1002
1003 static void __exit crypto_ccm_module_exit(void)
1004 {
1005         crypto_unregister_templates(crypto_ccm_tmpls,
1006                                     ARRAY_SIZE(crypto_ccm_tmpls));
1007 }
1008
1009 subsys_initcall(crypto_ccm_module_init);
1010 module_exit(crypto_ccm_module_exit);
1011
1012 MODULE_LICENSE("GPL");
1013 MODULE_DESCRIPTION("Counter with CBC MAC");
1014 MODULE_ALIAS_CRYPTO("ccm_base");
1015 MODULE_ALIAS_CRYPTO("rfc4309");
1016 MODULE_ALIAS_CRYPTO("ccm");