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 int crypto_ccm_base_create(struct crypto_template *tmpl,
 593                                   struct rtattr **tb)
 594 {
 595         const char *ctr_name;
 596         const char *cipher_name;
 597         char full_name[CRYPTO_MAX_ALG_NAME];
 598
 599         ctr_name = crypto_attr_alg_name(tb[1]);
 600         if (IS_ERR(ctr_name))
 601                 return PTR_ERR(ctr_name);
 602
 603         cipher_name = crypto_attr_alg_name(tb[2]);
 604         if (IS_ERR(cipher_name))
 605                 return PTR_ERR(cipher_name);
 606
 607         if (snprintf(full_name, CRYPTO_MAX_ALG_NAME, "ccm_base(%s,%s)",
 608                      ctr_name, cipher_name) >= CRYPTO_MAX_ALG_NAME)
 609                 return -ENAMETOOLONG;
 610
 611         return crypto_ccm_create_common(tmpl, tb, full_name, ctr_name,
 612                                         cipher_name);
 613 }
 614
 615 static int crypto_rfc4309_setkey(struct crypto_aead *parent, const u8 *key,
 616                                  unsigned int keylen)
 617 {
 618         struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(parent);
 619         struct crypto_aead *child = ctx->child;
 620         int err;
 621
 622         if (keylen < 3)
 623                 return -EINVAL;
 624
 625         keylen -= 3;
 626         memcpy(ctx->nonce, key + keylen, 3);
 627
 628         crypto_aead_clear_flags(child, CRYPTO_TFM_REQ_MASK);
 629         crypto_aead_set_flags(child, crypto_aead_get_flags(parent) &
 630                                      CRYPTO_TFM_REQ_MASK);
 631         err = crypto_aead_setkey(child, key, keylen);
 632         crypto_aead_set_flags(parent, crypto_aead_get_flags(child) &
 633                                       CRYPTO_TFM_RES_MASK);
 634
 635         return err;
 636 }
 637
 638 static int crypto_rfc4309_setauthsize(struct crypto_aead *parent,
 639                                       unsigned int authsize)
 640 {
 641         struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(parent);
 642
 643         switch (authsize) {
 644         case 8:
 645         case 12:
 646         case 16:
 647                 break;
 648         default:
 649                 return -EINVAL;
 650         }
 651
 652         return crypto_aead_setauthsize(ctx->child, authsize);
 653 }
 654
 655 static struct aead_request *crypto_rfc4309_crypt(struct aead_request *req)
 656 {
 657         struct crypto_rfc4309_req_ctx *rctx = aead_request_ctx(req);
 658         struct aead_request *subreq = &rctx->subreq;
 659         struct crypto_aead *aead = crypto_aead_reqtfm(req);
 660         struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(aead);
 661         struct crypto_aead *child = ctx->child;
 662         struct scatterlist *sg;
 663         u8 *iv = PTR_ALIGN((u8 *)(subreq + 1) + crypto_aead_reqsize(child),
 664                            crypto_aead_alignmask(child) + 1);
 665
 666         /* L' */
 667         iv[0] = 3;
 668
 669         memcpy(iv + 1, ctx->nonce, 3);
 670         memcpy(iv + 4, req->iv, 8);
 671
 672         scatterwalk_map_and_copy(iv + 16, req->src, 0, req->assoclen - 8, 0);
 673
 674         sg_init_table(rctx->src, 3);
 675         sg_set_buf(rctx->src, iv + 16, req->assoclen - 8);
 676         sg = scatterwalk_ffwd(rctx->src + 1, req->src, req->assoclen);
 677         if (sg != rctx->src + 1)
 678                 sg_chain(rctx->src, 2, sg);
 679
 680         if (req->src != req->dst) {
 681                 sg_init_table(rctx->dst, 3);
 682                 sg_set_buf(rctx->dst, iv + 16, req->assoclen - 8);
 683                 sg = scatterwalk_ffwd(rctx->dst + 1, req->dst, req->assoclen);
 684                 if (sg != rctx->dst + 1)
 685                         sg_chain(rctx->dst, 2, sg);
 686         }
 687
 688         aead_request_set_tfm(subreq, child);
 689         aead_request_set_callback(subreq, req->base.flags, req->base.complete,
 690                                   req->base.data);
 691         aead_request_set_crypt(subreq, rctx->src,
 692                                req->src == req->dst ? rctx->src : rctx->dst,
 693                                req->cryptlen, iv);
 694         aead_request_set_ad(subreq, req->assoclen - 8);
 695
 696         return subreq;
 697 }
 698
 699 static int crypto_rfc4309_encrypt(struct aead_request *req)
 700 {
 701         if (req->assoclen != 16 && req->assoclen != 20)
 702                 return -EINVAL;
 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         if (req->assoclen != 16 && req->assoclen != 20)
 712                 return -EINVAL;
 713
 714         req = crypto_rfc4309_crypt(req);
 715
 716         return crypto_aead_decrypt(req);
 717 }
 718
 719 static int crypto_rfc4309_init_tfm(struct crypto_aead *tfm)
 720 {
 721         struct aead_instance *inst = aead_alg_instance(tfm);
 722         struct crypto_aead_spawn *spawn = aead_instance_ctx(inst);
 723         struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(tfm);
 724         struct crypto_aead *aead;
 725         unsigned long align;
 726
 727         aead = crypto_spawn_aead(spawn);
 728         if (IS_ERR(aead))
 729                 return PTR_ERR(aead);
 730
 731         ctx->child = aead;
 732
 733         align = crypto_aead_alignmask(aead);
 734         align &= ~(crypto_tfm_ctx_alignment() - 1);
 735         crypto_aead_set_reqsize(
 736                 tfm,
 737                 sizeof(struct crypto_rfc4309_req_ctx) +
 738                 ALIGN(crypto_aead_reqsize(aead), crypto_tfm_ctx_alignment()) +
 739                 align + 32);
 740
 741         return 0;
 742 }
 743
 744 static void crypto_rfc4309_exit_tfm(struct crypto_aead *tfm)
 745 {
 746         struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(tfm);
 747
 748         crypto_free_aead(ctx->child);
 749 }
 750
 751 static void crypto_rfc4309_free(struct aead_instance *inst)
 752 {
 753         crypto_drop_aead(aead_instance_ctx(inst));
 754         kfree(inst);
 755 }
 756
 757 static int crypto_rfc4309_create(struct crypto_template *tmpl,
 758                                  struct rtattr **tb)
 759 {
 760         struct crypto_attr_type *algt;
 761         struct aead_instance *inst;
 762         struct crypto_aead_spawn *spawn;
 763         struct aead_alg *alg;
 764         const char *ccm_name;
 765         int err;
 766
 767         algt = crypto_get_attr_type(tb);
 768         if (IS_ERR(algt))
 769                 return PTR_ERR(algt);
 770
 771         if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
 772                 return -EINVAL;
 773
 774         ccm_name = crypto_attr_alg_name(tb[1]);
 775         if (IS_ERR(ccm_name))
 776                 return PTR_ERR(ccm_name);
 777
 778         inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
 779         if (!inst)
 780                 return -ENOMEM;
 781
 782         spawn = aead_instance_ctx(inst);
 783         crypto_set_aead_spawn(spawn, aead_crypto_instance(inst));
 784         err = crypto_grab_aead(spawn, ccm_name, 0,
 785                                crypto_requires_sync(algt->type, algt->mask));
 786         if (err)
 787                 goto out_free_inst;
 788
 789         alg = crypto_spawn_aead_alg(spawn);
 790
 791         err = -EINVAL;
 792
 793         /* We only support 16-byte blocks. */
 794         if (crypto_aead_alg_ivsize(alg) != 16)
 795                 goto out_drop_alg;
 796
 797         /* Not a stream cipher? */
 798         if (alg->base.cra_blocksize != 1)
 799                 goto out_drop_alg;
 800
 801         err = -ENAMETOOLONG;
 802         if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
 803                      "rfc4309(%s)", alg->base.cra_name) >=
 804             CRYPTO_MAX_ALG_NAME ||
 805             snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
 806                      "rfc4309(%s)", alg->base.cra_driver_name) >=
 807             CRYPTO_MAX_ALG_NAME)
 808                 goto out_drop_alg;
 809
 810         inst->alg.base.cra_flags = alg->base.cra_flags & CRYPTO_ALG_ASYNC;
 811         inst->alg.base.cra_priority = alg->base.cra_priority;
 812         inst->alg.base.cra_blocksize = 1;
 813         inst->alg.base.cra_alignmask = alg->base.cra_alignmask;
 814
 815         inst->alg.ivsize = 8;
 816         inst->alg.chunksize = crypto_aead_alg_chunksize(alg);
 817         inst->alg.maxauthsize = 16;
 818
 819         inst->alg.base.cra_ctxsize = sizeof(struct crypto_rfc4309_ctx);
 820
 821         inst->alg.init = crypto_rfc4309_init_tfm;
 822         inst->alg.exit = crypto_rfc4309_exit_tfm;
 823
 824         inst->alg.setkey = crypto_rfc4309_setkey;
 825         inst->alg.setauthsize = crypto_rfc4309_setauthsize;
 826         inst->alg.encrypt = crypto_rfc4309_encrypt;
 827         inst->alg.decrypt = crypto_rfc4309_decrypt;
 828
 829         inst->free = crypto_rfc4309_free;
 830
 831         err = aead_register_instance(tmpl, inst);
 832         if (err)
 833                 goto out_drop_alg;
 834
 835 out:
 836         return err;
 837
 838 out_drop_alg:
 839         crypto_drop_aead(spawn);
 840 out_free_inst:
 841         kfree(inst);
 842         goto out;
 843 }
 844
 845 static int crypto_cbcmac_digest_setkey(struct crypto_shash *parent,
 846                                      const u8 *inkey, unsigned int keylen)
 847 {
 848         struct cbcmac_tfm_ctx *ctx = crypto_shash_ctx(parent);
 849
 850         return crypto_cipher_setkey(ctx->child, inkey, keylen);
 851 }
 852
 853 static int crypto_cbcmac_digest_init(struct shash_desc *pdesc)
 854 {
 855         struct cbcmac_desc_ctx *ctx = shash_desc_ctx(pdesc);
 856         int bs = crypto_shash_digestsize(pdesc->tfm);
 857         u8 *dg = (u8 *)ctx + crypto_shash_descsize(pdesc->tfm) - bs;
 858
 859         ctx->len = 0;
 860         memset(dg, 0, bs);
 861
 862         return 0;
 863 }
 864
 865 static int crypto_cbcmac_digest_update(struct shash_desc *pdesc, const u8 *p,
 866                                        unsigned int len)
 867 {
 868         struct crypto_shash *parent = pdesc->tfm;
 869         struct cbcmac_tfm_ctx *tctx = crypto_shash_ctx(parent);
 870         struct cbcmac_desc_ctx *ctx = shash_desc_ctx(pdesc);
 871         struct crypto_cipher *tfm = tctx->child;
 872         int bs = crypto_shash_digestsize(parent);
 873         u8 *dg = (u8 *)ctx + crypto_shash_descsize(parent) - bs;
 874
 875         while (len > 0) {
 876                 unsigned int l = min(len, bs - ctx->len);
 877
 878                 crypto_xor(dg + ctx->len, p, l);
 879                 ctx->len +=l;
 880                 len -= l;
 881                 p += l;
 882
 883                 if (ctx->len == bs) {
 884                         crypto_cipher_encrypt_one(tfm, dg, dg);
 885                         ctx->len = 0;
 886                 }
 887         }
 888
 889         return 0;
 890 }
 891
 892 static int crypto_cbcmac_digest_final(struct shash_desc *pdesc, u8 *out)
 893 {
 894         struct crypto_shash *parent = pdesc->tfm;
 895         struct cbcmac_tfm_ctx *tctx = crypto_shash_ctx(parent);
 896         struct cbcmac_desc_ctx *ctx = shash_desc_ctx(pdesc);
 897         struct crypto_cipher *tfm = tctx->child;
 898         int bs = crypto_shash_digestsize(parent);
 899         u8 *dg = (u8 *)ctx + crypto_shash_descsize(parent) - bs;
 900
 901         if (ctx->len)
 902                 crypto_cipher_encrypt_one(tfm, dg, dg);
 903
 904         memcpy(out, dg, bs);
 905         return 0;
 906 }
 907
 908 static int cbcmac_init_tfm(struct crypto_tfm *tfm)
 909 {
 910         struct crypto_cipher *cipher;
 911         struct crypto_instance *inst = (void *)tfm->__crt_alg;
 912         struct crypto_spawn *spawn = crypto_instance_ctx(inst);
 913         struct cbcmac_tfm_ctx *ctx = crypto_tfm_ctx(tfm);
 914
 915         cipher = crypto_spawn_cipher(spawn);
 916         if (IS_ERR(cipher))
 917                 return PTR_ERR(cipher);
 918
 919         ctx->child = cipher;
 920
 921         return 0;
 922 };
 923
 924 static void cbcmac_exit_tfm(struct crypto_tfm *tfm)
 925 {
 926         struct cbcmac_tfm_ctx *ctx = crypto_tfm_ctx(tfm);
 927         crypto_free_cipher(ctx->child);
 928 }
 929
 930 static int cbcmac_create(struct crypto_template *tmpl, struct rtattr **tb)
 931 {
 932         struct shash_instance *inst;
 933         struct crypto_alg *alg;
 934         int err;
 935
 936         err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SHASH);
 937         if (err)
 938                 return err;
 939
 940         alg = crypto_get_attr_alg(tb, CRYPTO_ALG_TYPE_CIPHER,
 941                                   CRYPTO_ALG_TYPE_MASK);
 942         if (IS_ERR(alg))
 943                 return PTR_ERR(alg);
 944
 945         inst = shash_alloc_instance("cbcmac", alg);
 946         err = PTR_ERR(inst);
 947         if (IS_ERR(inst))
 948                 goto out_put_alg;
 949
 950         err = crypto_init_spawn(shash_instance_ctx(inst), alg,
 951                                 shash_crypto_instance(inst),
 952                                 CRYPTO_ALG_TYPE_MASK);
 953         if (err)
 954                 goto out_free_inst;
 955
 956         inst->alg.base.cra_priority = alg->cra_priority;
 957         inst->alg.base.cra_blocksize = 1;
 958
 959         inst->alg.digestsize = alg->cra_blocksize;
 960         inst->alg.descsize = ALIGN(sizeof(struct cbcmac_desc_ctx),
 961                                    alg->cra_alignmask + 1) +
 962                              alg->cra_blocksize;
 963
 964         inst->alg.base.cra_ctxsize = sizeof(struct cbcmac_tfm_ctx);
 965         inst->alg.base.cra_init = cbcmac_init_tfm;
 966         inst->alg.base.cra_exit = cbcmac_exit_tfm;
 967
 968         inst->alg.init = crypto_cbcmac_digest_init;
 969         inst->alg.update = crypto_cbcmac_digest_update;
 970         inst->alg.final = crypto_cbcmac_digest_final;
 971         inst->alg.setkey = crypto_cbcmac_digest_setkey;
 972
 973         err = shash_register_instance(tmpl, inst);
 974
 975 out_free_inst:
 976         if (err)
 977                 shash_free_instance(shash_crypto_instance(inst));
 978
 979 out_put_alg:
 980         crypto_mod_put(alg);
 981         return err;
 982 }
 983
 984 static struct crypto_template crypto_ccm_tmpls[] = {
 985         {
 986                 .name = "cbcmac",
 987                 .create = cbcmac_create,
 988                 .free = shash_free_instance,
 989                 .module = THIS_MODULE,
 990         }, {
 991                 .name = "ccm_base",
 992                 .create = crypto_ccm_base_create,
 993                 .module = THIS_MODULE,
 994         }, {
 995                 .name = "ccm",
 996                 .create = crypto_ccm_create,
 997                 .module = THIS_MODULE,
 998         }, {
 999                 .name = "rfc4309",
1000                 .create = crypto_rfc4309_create,
1001                 .module = THIS_MODULE,
1002         },
1003 };
1004
1005 static int __init crypto_ccm_module_init(void)
1006 {
1007         return crypto_register_templates(crypto_ccm_tmpls,
1008                                          ARRAY_SIZE(crypto_ccm_tmpls));
1009 }
1010
1011 static void __exit crypto_ccm_module_exit(void)
1012 {
1013         crypto_unregister_templates(crypto_ccm_tmpls,
1014                                     ARRAY_SIZE(crypto_ccm_tmpls));
1015 }
1016
1017 subsys_initcall(crypto_ccm_module_init);
1018 module_exit(crypto_ccm_module_exit);
1019
1020 MODULE_LICENSE("GPL");
1021 MODULE_DESCRIPTION("Counter with CBC MAC");
1022 MODULE_ALIAS_CRYPTO("ccm_base");
1023 MODULE_ALIAS_CRYPTO("rfc4309");
1024 MODULE_ALIAS_CRYPTO("ccm");