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 *full_name,
 462                                     const char *ctr_name,
 463                                     const char *mac_name)
 464 {
 465         struct crypto_attr_type *algt;
 466         struct aead_instance *inst;
 467         struct skcipher_alg *ctr;
 468         struct crypto_alg *mac_alg;
 469         struct hash_alg_common *mac;
 470         struct ccm_instance_ctx *ictx;
 471         int err;
 472
 473         algt = crypto_get_attr_type(tb);
 474         if (IS_ERR(algt))
 475                 return PTR_ERR(algt);
 476
 477         if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
 478                 return -EINVAL;
 479
 480         mac_alg = crypto_find_alg(mac_name, &crypto_ahash_type,
 481                                   CRYPTO_ALG_TYPE_HASH,
 482                                   CRYPTO_ALG_TYPE_AHASH_MASK |
 483                                   CRYPTO_ALG_ASYNC);
 484         if (IS_ERR(mac_alg))
 485                 return PTR_ERR(mac_alg);
 486
 487         mac = __crypto_hash_alg_common(mac_alg);
 488         err = -EINVAL;
 489         if (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         /* Not a stream cipher? */
 513         err = -EINVAL;
 514         if (ctr->base.cra_blocksize != 1)
 515                 goto err_drop_ctr;
 516
 517         /* We want the real thing! */
 518         if (crypto_skcipher_alg_ivsize(ctr) != 16)
 519                 goto err_drop_ctr;
 520
 521         err = -ENAMETOOLONG;
 522         if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
 523                      "ccm_base(%s,%s)", ctr->base.cra_driver_name,
 524                      mac->base.cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
 525                 goto err_drop_ctr;
 526
 527         memcpy(inst->alg.base.cra_name, full_name, CRYPTO_MAX_ALG_NAME);
 528
 529         inst->alg.base.cra_flags = ctr->base.cra_flags & CRYPTO_ALG_ASYNC;
 530         inst->alg.base.cra_priority = (mac->base.cra_priority +
 531                                        ctr->base.cra_priority) / 2;
 532         inst->alg.base.cra_blocksize = 1;
 533         inst->alg.base.cra_alignmask = mac->base.cra_alignmask |
 534                                        ctr->base.cra_alignmask;
 535         inst->alg.ivsize = 16;
 536         inst->alg.chunksize = crypto_skcipher_alg_chunksize(ctr);
 537         inst->alg.maxauthsize = 16;
 538         inst->alg.base.cra_ctxsize = sizeof(struct crypto_ccm_ctx);
 539         inst->alg.init = crypto_ccm_init_tfm;
 540         inst->alg.exit = crypto_ccm_exit_tfm;
 541         inst->alg.setkey = crypto_ccm_setkey;
 542         inst->alg.setauthsize = crypto_ccm_setauthsize;
 543         inst->alg.encrypt = crypto_ccm_encrypt;
 544         inst->alg.decrypt = crypto_ccm_decrypt;
 545
 546         inst->free = crypto_ccm_free;
 547
 548         err = aead_register_instance(tmpl, inst);
 549         if (err)
 550                 goto err_drop_ctr;
 551
 552 out_put_mac:
 553         crypto_mod_put(mac_alg);
 554         return err;
 555
 556 err_drop_ctr:
 557         crypto_drop_skcipher(&ictx->ctr);
 558 err_drop_mac:
 559         crypto_drop_ahash(&ictx->mac);
 560 err_free_inst:
 561         kfree(inst);
 562         goto out_put_mac;
 563 }
 564
 565 static int crypto_ccm_create(struct crypto_template *tmpl, struct rtattr **tb)
 566 {
 567         const char *cipher_name;
 568         char ctr_name[CRYPTO_MAX_ALG_NAME];
 569         char mac_name[CRYPTO_MAX_ALG_NAME];
 570         char full_name[CRYPTO_MAX_ALG_NAME];
 571
 572         cipher_name = crypto_attr_alg_name(tb[1]);
 573         if (IS_ERR(cipher_name))
 574                 return PTR_ERR(cipher_name);
 575
 576         if (snprintf(ctr_name, CRYPTO_MAX_ALG_NAME, "ctr(%s)",
 577                      cipher_name) >= CRYPTO_MAX_ALG_NAME)
 578                 return -ENAMETOOLONG;
 579
 580         if (snprintf(mac_name, CRYPTO_MAX_ALG_NAME, "cbcmac(%s)",
 581                      cipher_name) >= CRYPTO_MAX_ALG_NAME)
 582                 return -ENAMETOOLONG;
 583
 584         if (snprintf(full_name, CRYPTO_MAX_ALG_NAME, "ccm(%s)", cipher_name) >=
 585             CRYPTO_MAX_ALG_NAME)
 586                 return -ENAMETOOLONG;
 587
 588         return crypto_ccm_create_common(tmpl, tb, full_name, ctr_name,
 589                                         mac_name);
 590 }
 591
 592 static struct crypto_template crypto_ccm_tmpl = {
 593         .name = "ccm",
 594         .create = crypto_ccm_create,
 595         .module = THIS_MODULE,
 596 };
 597
 598 static int crypto_ccm_base_create(struct crypto_template *tmpl,
 599                                   struct rtattr **tb)
 600 {
 601         const char *ctr_name;
 602         const char *cipher_name;
 603         char full_name[CRYPTO_MAX_ALG_NAME];
 604
 605         ctr_name = crypto_attr_alg_name(tb[1]);
 606         if (IS_ERR(ctr_name))
 607                 return PTR_ERR(ctr_name);
 608
 609         cipher_name = crypto_attr_alg_name(tb[2]);
 610         if (IS_ERR(cipher_name))
 611                 return PTR_ERR(cipher_name);
 612
 613         if (snprintf(full_name, CRYPTO_MAX_ALG_NAME, "ccm_base(%s,%s)",
 614                      ctr_name, cipher_name) >= CRYPTO_MAX_ALG_NAME)
 615                 return -ENAMETOOLONG;
 616
 617         return crypto_ccm_create_common(tmpl, tb, full_name, ctr_name,
 618                                         cipher_name);
 619 }
 620
 621 static struct crypto_template crypto_ccm_base_tmpl = {
 622         .name = "ccm_base",
 623         .create = crypto_ccm_base_create,
 624         .module = THIS_MODULE,
 625 };
 626
 627 static int crypto_rfc4309_setkey(struct crypto_aead *parent, const u8 *key,
 628                                  unsigned int keylen)
 629 {
 630         struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(parent);
 631         struct crypto_aead *child = ctx->child;
 632         int err;
 633
 634         if (keylen < 3)
 635                 return -EINVAL;
 636
 637         keylen -= 3;
 638         memcpy(ctx->nonce, key + keylen, 3);
 639
 640         crypto_aead_clear_flags(child, CRYPTO_TFM_REQ_MASK);
 641         crypto_aead_set_flags(child, crypto_aead_get_flags(parent) &
 642                                      CRYPTO_TFM_REQ_MASK);
 643         err = crypto_aead_setkey(child, key, keylen);
 644         crypto_aead_set_flags(parent, crypto_aead_get_flags(child) &
 645                                       CRYPTO_TFM_RES_MASK);
 646
 647         return err;
 648 }
 649
 650 static int crypto_rfc4309_setauthsize(struct crypto_aead *parent,
 651                                       unsigned int authsize)
 652 {
 653         struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(parent);
 654
 655         switch (authsize) {
 656         case 8:
 657         case 12:
 658         case 16:
 659                 break;
 660         default:
 661                 return -EINVAL;
 662         }
 663
 664         return crypto_aead_setauthsize(ctx->child, authsize);
 665 }
 666
 667 static struct aead_request *crypto_rfc4309_crypt(struct aead_request *req)
 668 {
 669         struct crypto_rfc4309_req_ctx *rctx = aead_request_ctx(req);
 670         struct aead_request *subreq = &rctx->subreq;
 671         struct crypto_aead *aead = crypto_aead_reqtfm(req);
 672         struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(aead);
 673         struct crypto_aead *child = ctx->child;
 674         struct scatterlist *sg;
 675         u8 *iv = PTR_ALIGN((u8 *)(subreq + 1) + crypto_aead_reqsize(child),
 676                            crypto_aead_alignmask(child) + 1);
 677
 678         /* L' */
 679         iv[0] = 3;
 680
 681         memcpy(iv + 1, ctx->nonce, 3);
 682         memcpy(iv + 4, req->iv, 8);
 683
 684         scatterwalk_map_and_copy(iv + 16, req->src, 0, req->assoclen - 8, 0);
 685
 686         sg_init_table(rctx->src, 3);
 687         sg_set_buf(rctx->src, iv + 16, req->assoclen - 8);
 688         sg = scatterwalk_ffwd(rctx->src + 1, req->src, req->assoclen);
 689         if (sg != rctx->src + 1)
 690                 sg_chain(rctx->src, 2, sg);
 691
 692         if (req->src != req->dst) {
 693                 sg_init_table(rctx->dst, 3);
 694                 sg_set_buf(rctx->dst, iv + 16, req->assoclen - 8);
 695                 sg = scatterwalk_ffwd(rctx->dst + 1, req->dst, req->assoclen);
 696                 if (sg != rctx->dst + 1)
 697                         sg_chain(rctx->dst, 2, sg);
 698         }
 699
 700         aead_request_set_tfm(subreq, child);
 701         aead_request_set_callback(subreq, req->base.flags, req->base.complete,
 702                                   req->base.data);
 703         aead_request_set_crypt(subreq, rctx->src,
 704                                req->src == req->dst ? rctx->src : rctx->dst,
 705                                req->cryptlen, iv);
 706         aead_request_set_ad(subreq, req->assoclen - 8);
 707
 708         return subreq;
 709 }
 710
 711 static int crypto_rfc4309_encrypt(struct aead_request *req)
 712 {
 713         if (req->assoclen != 16 && req->assoclen != 20)
 714                 return -EINVAL;
 715
 716         req = crypto_rfc4309_crypt(req);
 717
 718         return crypto_aead_encrypt(req);
 719 }
 720
 721 static int crypto_rfc4309_decrypt(struct aead_request *req)
 722 {
 723         if (req->assoclen != 16 && req->assoclen != 20)
 724                 return -EINVAL;
 725
 726         req = crypto_rfc4309_crypt(req);
 727
 728         return crypto_aead_decrypt(req);
 729 }
 730
 731 static int crypto_rfc4309_init_tfm(struct crypto_aead *tfm)
 732 {
 733         struct aead_instance *inst = aead_alg_instance(tfm);
 734         struct crypto_aead_spawn *spawn = aead_instance_ctx(inst);
 735         struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(tfm);
 736         struct crypto_aead *aead;
 737         unsigned long align;
 738
 739         aead = crypto_spawn_aead(spawn);
 740         if (IS_ERR(aead))
 741                 return PTR_ERR(aead);
 742
 743         ctx->child = aead;
 744
 745         align = crypto_aead_alignmask(aead);
 746         align &= ~(crypto_tfm_ctx_alignment() - 1);
 747         crypto_aead_set_reqsize(
 748                 tfm,
 749                 sizeof(struct crypto_rfc4309_req_ctx) +
 750                 ALIGN(crypto_aead_reqsize(aead), crypto_tfm_ctx_alignment()) +
 751                 align + 32);
 752
 753         return 0;
 754 }
 755
 756 static void crypto_rfc4309_exit_tfm(struct crypto_aead *tfm)
 757 {
 758         struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(tfm);
 759
 760         crypto_free_aead(ctx->child);
 761 }
 762
 763 static void crypto_rfc4309_free(struct aead_instance *inst)
 764 {
 765         crypto_drop_aead(aead_instance_ctx(inst));
 766         kfree(inst);
 767 }
 768
 769 static int crypto_rfc4309_create(struct crypto_template *tmpl,
 770                                  struct rtattr **tb)
 771 {
 772         struct crypto_attr_type *algt;
 773         struct aead_instance *inst;
 774         struct crypto_aead_spawn *spawn;
 775         struct aead_alg *alg;
 776         const char *ccm_name;
 777         int err;
 778
 779         algt = crypto_get_attr_type(tb);
 780         if (IS_ERR(algt))
 781                 return PTR_ERR(algt);
 782
 783         if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
 784                 return -EINVAL;
 785
 786         ccm_name = crypto_attr_alg_name(tb[1]);
 787         if (IS_ERR(ccm_name))
 788                 return PTR_ERR(ccm_name);
 789
 790         inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
 791         if (!inst)
 792                 return -ENOMEM;
 793
 794         spawn = aead_instance_ctx(inst);
 795         crypto_set_aead_spawn(spawn, aead_crypto_instance(inst));
 796         err = crypto_grab_aead(spawn, ccm_name, 0,
 797                                crypto_requires_sync(algt->type, algt->mask));
 798         if (err)
 799                 goto out_free_inst;
 800
 801         alg = crypto_spawn_aead_alg(spawn);
 802
 803         err = -EINVAL;
 804
 805         /* We only support 16-byte blocks. */
 806         if (crypto_aead_alg_ivsize(alg) != 16)
 807                 goto out_drop_alg;
 808
 809         /* Not a stream cipher? */
 810         if (alg->base.cra_blocksize != 1)
 811                 goto out_drop_alg;
 812
 813         err = -ENAMETOOLONG;
 814         if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
 815                      "rfc4309(%s)", alg->base.cra_name) >=
 816             CRYPTO_MAX_ALG_NAME ||
 817             snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
 818                      "rfc4309(%s)", alg->base.cra_driver_name) >=
 819             CRYPTO_MAX_ALG_NAME)
 820                 goto out_drop_alg;
 821
 822         inst->alg.base.cra_flags = alg->base.cra_flags & CRYPTO_ALG_ASYNC;
 823         inst->alg.base.cra_priority = alg->base.cra_priority;
 824         inst->alg.base.cra_blocksize = 1;
 825         inst->alg.base.cra_alignmask = alg->base.cra_alignmask;
 826
 827         inst->alg.ivsize = 8;
 828         inst->alg.chunksize = crypto_aead_alg_chunksize(alg);
 829         inst->alg.maxauthsize = 16;
 830
 831         inst->alg.base.cra_ctxsize = sizeof(struct crypto_rfc4309_ctx);
 832
 833         inst->alg.init = crypto_rfc4309_init_tfm;
 834         inst->alg.exit = crypto_rfc4309_exit_tfm;
 835
 836         inst->alg.setkey = crypto_rfc4309_setkey;
 837         inst->alg.setauthsize = crypto_rfc4309_setauthsize;
 838         inst->alg.encrypt = crypto_rfc4309_encrypt;
 839         inst->alg.decrypt = crypto_rfc4309_decrypt;
 840
 841         inst->free = crypto_rfc4309_free;
 842
 843         err = aead_register_instance(tmpl, inst);
 844         if (err)
 845                 goto out_drop_alg;
 846
 847 out:
 848         return err;
 849
 850 out_drop_alg:
 851         crypto_drop_aead(spawn);
 852 out_free_inst:
 853         kfree(inst);
 854         goto out;
 855 }
 856
 857 static struct crypto_template crypto_rfc4309_tmpl = {
 858         .name = "rfc4309",
 859         .create = crypto_rfc4309_create,
 860         .module = THIS_MODULE,
 861 };
 862
 863 static int crypto_cbcmac_digest_setkey(struct crypto_shash *parent,
 864                                      const u8 *inkey, unsigned int keylen)
 865 {
 866         struct cbcmac_tfm_ctx *ctx = crypto_shash_ctx(parent);
 867
 868         return crypto_cipher_setkey(ctx->child, inkey, keylen);
 869 }
 870
 871 static int crypto_cbcmac_digest_init(struct shash_desc *pdesc)
 872 {
 873         struct cbcmac_desc_ctx *ctx = shash_desc_ctx(pdesc);
 874         int bs = crypto_shash_digestsize(pdesc->tfm);
 875         u8 *dg = (u8 *)ctx + crypto_shash_descsize(pdesc->tfm) - bs;
 876
 877         ctx->len = 0;
 878         memset(dg, 0, bs);
 879
 880         return 0;
 881 }
 882
 883 static int crypto_cbcmac_digest_update(struct shash_desc *pdesc, const u8 *p,
 884                                        unsigned int len)
 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         while (len > 0) {
 894                 unsigned int l = min(len, bs - ctx->len);
 895
 896                 crypto_xor(dg + ctx->len, p, l);
 897                 ctx->len +=l;
 898                 len -= l;
 899                 p += l;
 900
 901                 if (ctx->len == bs) {
 902                         crypto_cipher_encrypt_one(tfm, dg, dg);
 903                         ctx->len = 0;
 904                 }
 905         }
 906
 907         return 0;
 908 }
 909
 910 static int crypto_cbcmac_digest_final(struct shash_desc *pdesc, u8 *out)
 911 {
 912         struct crypto_shash *parent = pdesc->tfm;
 913         struct cbcmac_tfm_ctx *tctx = crypto_shash_ctx(parent);
 914         struct cbcmac_desc_ctx *ctx = shash_desc_ctx(pdesc);
 915         struct crypto_cipher *tfm = tctx->child;
 916         int bs = crypto_shash_digestsize(parent);
 917         u8 *dg = (u8 *)ctx + crypto_shash_descsize(parent) - bs;
 918
 919         if (ctx->len)
 920                 crypto_cipher_encrypt_one(tfm, dg, dg);
 921
 922         memcpy(out, dg, bs);
 923         return 0;
 924 }
 925
 926 static int cbcmac_init_tfm(struct crypto_tfm *tfm)
 927 {
 928         struct crypto_cipher *cipher;
 929         struct crypto_instance *inst = (void *)tfm->__crt_alg;
 930         struct crypto_spawn *spawn = crypto_instance_ctx(inst);
 931         struct cbcmac_tfm_ctx *ctx = crypto_tfm_ctx(tfm);
 932
 933         cipher = crypto_spawn_cipher(spawn);
 934         if (IS_ERR(cipher))
 935                 return PTR_ERR(cipher);
 936
 937         ctx->child = cipher;
 938
 939         return 0;
 940 };
 941
 942 static void cbcmac_exit_tfm(struct crypto_tfm *tfm)
 943 {
 944         struct cbcmac_tfm_ctx *ctx = crypto_tfm_ctx(tfm);
 945         crypto_free_cipher(ctx->child);
 946 }
 947
 948 static int cbcmac_create(struct crypto_template *tmpl, struct rtattr **tb)
 949 {
 950         struct shash_instance *inst;
 951         struct crypto_alg *alg;
 952         int err;
 953
 954         err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SHASH);
 955         if (err)
 956                 return err;
 957
 958         alg = crypto_get_attr_alg(tb, CRYPTO_ALG_TYPE_CIPHER,
 959                                   CRYPTO_ALG_TYPE_MASK);
 960         if (IS_ERR(alg))
 961                 return PTR_ERR(alg);
 962
 963         inst = shash_alloc_instance("cbcmac", alg);
 964         err = PTR_ERR(inst);
 965         if (IS_ERR(inst))
 966                 goto out_put_alg;
 967
 968         err = crypto_init_spawn(shash_instance_ctx(inst), alg,
 969                                 shash_crypto_instance(inst),
 970                                 CRYPTO_ALG_TYPE_MASK);
 971         if (err)
 972                 goto out_free_inst;
 973
 974         inst->alg.base.cra_priority = alg->cra_priority;
 975         inst->alg.base.cra_blocksize = 1;
 976
 977         inst->alg.digestsize = alg->cra_blocksize;
 978         inst->alg.descsize = ALIGN(sizeof(struct cbcmac_desc_ctx),
 979                                    alg->cra_alignmask + 1) +
 980                              alg->cra_blocksize;
 981
 982         inst->alg.base.cra_ctxsize = sizeof(struct cbcmac_tfm_ctx);
 983         inst->alg.base.cra_init = cbcmac_init_tfm;
 984         inst->alg.base.cra_exit = cbcmac_exit_tfm;
 985
 986         inst->alg.init = crypto_cbcmac_digest_init;
 987         inst->alg.update = crypto_cbcmac_digest_update;
 988         inst->alg.final = crypto_cbcmac_digest_final;
 989         inst->alg.setkey = crypto_cbcmac_digest_setkey;
 990
 991         err = shash_register_instance(tmpl, inst);
 992
 993 out_free_inst:
 994         if (err)
 995                 shash_free_instance(shash_crypto_instance(inst));
 996
 997 out_put_alg:
 998         crypto_mod_put(alg);
 999         return err;
1000 }
1001
1002 static struct crypto_template crypto_cbcmac_tmpl = {
1003         .name = "cbcmac",
1004         .create = cbcmac_create,
1005         .free = shash_free_instance,
1006         .module = THIS_MODULE,
1007 };
1008
1009 static int __init crypto_ccm_module_init(void)
1010 {
1011         int err;
1012
1013         err = crypto_register_template(&crypto_cbcmac_tmpl);
1014         if (err)
1015                 goto out;
1016
1017         err = crypto_register_template(&crypto_ccm_base_tmpl);
1018         if (err)
1019                 goto out_undo_cbcmac;
1020
1021         err = crypto_register_template(&crypto_ccm_tmpl);
1022         if (err)
1023                 goto out_undo_base;
1024
1025         err = crypto_register_template(&crypto_rfc4309_tmpl);
1026         if (err)
1027                 goto out_undo_ccm;
1028
1029 out:
1030         return err;
1031
1032 out_undo_ccm:
1033         crypto_unregister_template(&crypto_ccm_tmpl);
1034 out_undo_base:
1035         crypto_unregister_template(&crypto_ccm_base_tmpl);
1036 out_undo_cbcmac:
1037         crypto_register_template(&crypto_cbcmac_tmpl);
1038         goto out;
1039 }
1040
1041 static void __exit crypto_ccm_module_exit(void)
1042 {
1043         crypto_unregister_template(&crypto_rfc4309_tmpl);
1044         crypto_unregister_template(&crypto_ccm_tmpl);
1045         crypto_unregister_template(&crypto_ccm_base_tmpl);
1046         crypto_unregister_template(&crypto_cbcmac_tmpl);
1047 }
1048
1049 module_init(crypto_ccm_module_init);
1050 module_exit(crypto_ccm_module_exit);
1051
1052 MODULE_LICENSE("GPL");
1053 MODULE_DESCRIPTION("Counter with CBC MAC");
1054 MODULE_ALIAS_CRYPTO("ccm_base");
1055 MODULE_ALIAS_CRYPTO("rfc4309");
1056 MODULE_ALIAS_CRYPTO("ccm");