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         struct skcipher_request skreq;
  54 };
  55
  56 struct cbcmac_tfm_ctx {
  57         struct crypto_cipher *child;
  58 };
  59
  60 struct cbcmac_desc_ctx {
  61         unsigned int len;
  62 };
  63
  64 static inline struct crypto_ccm_req_priv_ctx *crypto_ccm_reqctx(
  65         struct aead_request *req)
  66 {
  67         unsigned long align = crypto_aead_alignmask(crypto_aead_reqtfm(req));
  68
  69         return (void *)PTR_ALIGN((u8 *)aead_request_ctx(req), align + 1);
  70 }
  71
  72 static int set_msg_len(u8 *block, unsigned int msglen, int csize)
  73 {
  74         __be32 data;
  75
  76         memset(block, 0, csize);
  77         block += csize;
  78
  79         if (csize >= 4)
  80                 csize = 4;
  81         else if (msglen > (1 << (8 * csize)))
  82                 return -EOVERFLOW;
  83
  84         data = cpu_to_be32(msglen);
  85         memcpy(block - csize, (u8 *)&data + 4 - csize, csize);
  86
  87         return 0;
  88 }
  89
  90 static int crypto_ccm_setkey(struct crypto_aead *aead, const u8 *key,
  91                              unsigned int keylen)
  92 {
  93         struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
  94         struct crypto_skcipher *ctr = ctx->ctr;
  95         struct crypto_ahash *mac = ctx->mac;
  96         int err = 0;
  97
  98         crypto_skcipher_clear_flags(ctr, CRYPTO_TFM_REQ_MASK);
  99         crypto_skcipher_set_flags(ctr, crypto_aead_get_flags(aead) &
 100                                        CRYPTO_TFM_REQ_MASK);
 101         err = crypto_skcipher_setkey(ctr, key, keylen);
 102         crypto_aead_set_flags(aead, crypto_skcipher_get_flags(ctr) &
 103                               CRYPTO_TFM_RES_MASK);
 104         if (err)
 105                 goto out;
 106
 107         crypto_ahash_clear_flags(mac, CRYPTO_TFM_REQ_MASK);
 108         crypto_ahash_set_flags(mac, crypto_aead_get_flags(aead) &
 109                                     CRYPTO_TFM_REQ_MASK);
 110         err = crypto_ahash_setkey(mac, key, keylen);
 111         crypto_aead_set_flags(aead, crypto_ahash_get_flags(mac) &
 112                               CRYPTO_TFM_RES_MASK);
 113
 114 out:
 115         return err;
 116 }
 117
 118 static int crypto_ccm_setauthsize(struct crypto_aead *tfm,
 119                                   unsigned int authsize)
 120 {
 121         switch (authsize) {
 122         case 4:
 123         case 6:
 124         case 8:
 125         case 10:
 126         case 12:
 127         case 14:
 128         case 16:
 129                 break;
 130         default:
 131                 return -EINVAL;
 132         }
 133
 134         return 0;
 135 }
 136
 137 static int format_input(u8 *info, struct aead_request *req,
 138                         unsigned int cryptlen)
 139 {
 140         struct crypto_aead *aead = crypto_aead_reqtfm(req);
 141         unsigned int lp = req->iv[0];
 142         unsigned int l = lp + 1;
 143         unsigned int m;
 144
 145         m = crypto_aead_authsize(aead);
 146
 147         memcpy(info, req->iv, 16);
 148
 149         /* format control info per RFC 3610 and
 150          * NIST Special Publication 800-38C
 151          */
 152         *info |= (8 * ((m - 2) / 2));
 153         if (req->assoclen)
 154                 *info |= 64;
 155
 156         return set_msg_len(info + 16 - l, cryptlen, l);
 157 }
 158
 159 static int format_adata(u8 *adata, unsigned int a)
 160 {
 161         int len = 0;
 162
 163         /* add control info for associated data
 164          * RFC 3610 and NIST Special Publication 800-38C
 165          */
 166         if (a < 65280) {
 167                 *(__be16 *)adata = cpu_to_be16(a);
 168                 len = 2;
 169         } else  {
 170                 *(__be16 *)adata = cpu_to_be16(0xfffe);
 171                 *(__be32 *)&adata[2] = cpu_to_be32(a);
 172                 len = 6;
 173         }
 174
 175         return len;
 176 }
 177
 178 static int crypto_ccm_auth(struct aead_request *req, struct scatterlist *plain,
 179                            unsigned int cryptlen)
 180 {
 181         struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
 182         struct crypto_aead *aead = crypto_aead_reqtfm(req);
 183         struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
 184         AHASH_REQUEST_ON_STACK(ahreq, ctx->mac);
 185         unsigned int assoclen = req->assoclen;
 186         struct scatterlist sg[3];
 187         u8 *odata = pctx->odata;
 188         u8 *idata = pctx->idata;
 189         int ilen, err;
 190
 191         /* format control data for input */
 192         err = format_input(odata, req, cryptlen);
 193         if (err)
 194                 goto out;
 195
 196         sg_init_table(sg, 3);
 197         sg_set_buf(&sg[0], odata, 16);
 198
 199         /* format associated data and compute into mac */
 200         if (assoclen) {
 201                 ilen = format_adata(idata, assoclen);
 202                 sg_set_buf(&sg[1], idata, ilen);
 203                 sg_chain(sg, 3, req->src);
 204         } else {
 205                 ilen = 0;
 206                 sg_chain(sg, 2, req->src);
 207         }
 208
 209         ahash_request_set_tfm(ahreq, ctx->mac);
 210         ahash_request_set_callback(ahreq, pctx->flags, NULL, NULL);
 211         ahash_request_set_crypt(ahreq, sg, NULL, assoclen + ilen + 16);
 212         err = crypto_ahash_init(ahreq);
 213         if (err)
 214                 goto out;
 215         err = crypto_ahash_update(ahreq);
 216         if (err)
 217                 goto out;
 218
 219         /* we need to pad the MAC input to a round multiple of the block size */
 220         ilen = 16 - (assoclen + ilen) % 16;
 221         if (ilen < 16) {
 222                 memset(idata, 0, ilen);
 223                 sg_init_table(sg, 2);
 224                 sg_set_buf(&sg[0], idata, ilen);
 225                 if (plain)
 226                         sg_chain(sg, 2, plain);
 227                 plain = sg;
 228                 cryptlen += ilen;
 229         }
 230
 231         ahash_request_set_crypt(ahreq, plain, pctx->odata, cryptlen);
 232         err = crypto_ahash_finup(ahreq);
 233 out:
 234         return err;
 235 }
 236
 237 static void crypto_ccm_encrypt_done(struct crypto_async_request *areq, int err)
 238 {
 239         struct aead_request *req = areq->data;
 240         struct crypto_aead *aead = crypto_aead_reqtfm(req);
 241         struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
 242         u8 *odata = pctx->odata;
 243
 244         if (!err)
 245                 scatterwalk_map_and_copy(odata, req->dst,
 246                                          req->assoclen + req->cryptlen,
 247                                          crypto_aead_authsize(aead), 1);
 248         aead_request_complete(req, err);
 249 }
 250
 251 static inline int crypto_ccm_check_iv(const u8 *iv)
 252 {
 253         /* 2 <= L <= 8, so 1 <= L' <= 7. */
 254         if (1 > iv[0] || iv[0] > 7)
 255                 return -EINVAL;
 256
 257         return 0;
 258 }
 259
 260 static int crypto_ccm_init_crypt(struct aead_request *req, u8 *tag)
 261 {
 262         struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
 263         struct scatterlist *sg;
 264         u8 *iv = req->iv;
 265         int err;
 266
 267         err = crypto_ccm_check_iv(iv);
 268         if (err)
 269                 return err;
 270
 271         pctx->flags = aead_request_flags(req);
 272
 273          /* Note: rfc 3610 and NIST 800-38C require counter of
 274          * zero to encrypt auth tag.
 275          */
 276         memset(iv + 15 - iv[0], 0, iv[0] + 1);
 277
 278         sg_init_table(pctx->src, 3);
 279         sg_set_buf(pctx->src, tag, 16);
 280         sg = scatterwalk_ffwd(pctx->src + 1, req->src, req->assoclen);
 281         if (sg != pctx->src + 1)
 282                 sg_chain(pctx->src, 2, sg);
 283
 284         if (req->src != req->dst) {
 285                 sg_init_table(pctx->dst, 3);
 286                 sg_set_buf(pctx->dst, tag, 16);
 287                 sg = scatterwalk_ffwd(pctx->dst + 1, req->dst, req->assoclen);
 288                 if (sg != pctx->dst + 1)
 289                         sg_chain(pctx->dst, 2, sg);
 290         }
 291
 292         return 0;
 293 }
 294
 295 static int crypto_ccm_encrypt(struct aead_request *req)
 296 {
 297         struct crypto_aead *aead = crypto_aead_reqtfm(req);
 298         struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
 299         struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
 300         struct skcipher_request *skreq = &pctx->skreq;
 301         struct scatterlist *dst;
 302         unsigned int cryptlen = req->cryptlen;
 303         u8 *odata = pctx->odata;
 304         u8 *iv = req->iv;
 305         int err;
 306
 307         err = crypto_ccm_init_crypt(req, odata);
 308         if (err)
 309                 return err;
 310
 311         err = crypto_ccm_auth(req, sg_next(pctx->src), cryptlen);
 312         if (err)
 313                 return err;
 314
 315         dst = pctx->src;
 316         if (req->src != req->dst)
 317                 dst = pctx->dst;
 318
 319         skcipher_request_set_tfm(skreq, ctx->ctr);
 320         skcipher_request_set_callback(skreq, pctx->flags,
 321                                       crypto_ccm_encrypt_done, req);
 322         skcipher_request_set_crypt(skreq, pctx->src, dst, cryptlen + 16, iv);
 323         err = crypto_skcipher_encrypt(skreq);
 324         if (err)
 325                 return err;
 326
 327         /* copy authtag to end of dst */
 328         scatterwalk_map_and_copy(odata, sg_next(dst), cryptlen,
 329                                  crypto_aead_authsize(aead), 1);
 330         return err;
 331 }
 332
 333 static void crypto_ccm_decrypt_done(struct crypto_async_request *areq,
 334                                    int err)
 335 {
 336         struct aead_request *req = areq->data;
 337         struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
 338         struct crypto_aead *aead = crypto_aead_reqtfm(req);
 339         unsigned int authsize = crypto_aead_authsize(aead);
 340         unsigned int cryptlen = req->cryptlen - authsize;
 341         struct scatterlist *dst;
 342
 343         pctx->flags = 0;
 344
 345         dst = sg_next(req->src == req->dst ? pctx->src : pctx->dst);
 346
 347         if (!err) {
 348                 err = crypto_ccm_auth(req, dst, cryptlen);
 349                 if (!err && crypto_memneq(pctx->auth_tag, pctx->odata, authsize))
 350                         err = -EBADMSG;
 351         }
 352         aead_request_complete(req, err);
 353 }
 354
 355 static int crypto_ccm_decrypt(struct aead_request *req)
 356 {
 357         struct crypto_aead *aead = crypto_aead_reqtfm(req);
 358         struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
 359         struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
 360         struct skcipher_request *skreq = &pctx->skreq;
 361         struct scatterlist *dst;
 362         unsigned int authsize = crypto_aead_authsize(aead);
 363         unsigned int cryptlen = req->cryptlen;
 364         u8 *authtag = pctx->auth_tag;
 365         u8 *odata = pctx->odata;
 366         u8 *iv = req->iv;
 367         int err;
 368
 369         cryptlen -= authsize;
 370
 371         err = crypto_ccm_init_crypt(req, authtag);
 372         if (err)
 373                 return err;
 374
 375         scatterwalk_map_and_copy(authtag, sg_next(pctx->src), cryptlen,
 376                                  authsize, 0);
 377
 378         dst = pctx->src;
 379         if (req->src != req->dst)
 380                 dst = pctx->dst;
 381
 382         skcipher_request_set_tfm(skreq, ctx->ctr);
 383         skcipher_request_set_callback(skreq, pctx->flags,
 384                                       crypto_ccm_decrypt_done, req);
 385         skcipher_request_set_crypt(skreq, pctx->src, dst, cryptlen + 16, iv);
 386         err = crypto_skcipher_decrypt(skreq);
 387         if (err)
 388                 return err;
 389
 390         err = crypto_ccm_auth(req, sg_next(dst), cryptlen);
 391         if (err)
 392                 return err;
 393
 394         /* verify */
 395         if (crypto_memneq(authtag, odata, authsize))
 396                 return -EBADMSG;
 397
 398         return err;
 399 }
 400
 401 static int crypto_ccm_init_tfm(struct crypto_aead *tfm)
 402 {
 403         struct aead_instance *inst = aead_alg_instance(tfm);
 404         struct ccm_instance_ctx *ictx = aead_instance_ctx(inst);
 405         struct crypto_ccm_ctx *ctx = crypto_aead_ctx(tfm);
 406         struct crypto_ahash *mac;
 407         struct crypto_skcipher *ctr;
 408         unsigned long align;
 409         int err;
 410
 411         mac = crypto_spawn_ahash(&ictx->mac);
 412         if (IS_ERR(mac))
 413                 return PTR_ERR(mac);
 414
 415         ctr = crypto_spawn_skcipher(&ictx->ctr);
 416         err = PTR_ERR(ctr);
 417         if (IS_ERR(ctr))
 418                 goto err_free_mac;
 419
 420         ctx->mac = mac;
 421         ctx->ctr = ctr;
 422
 423         align = crypto_aead_alignmask(tfm);
 424         align &= ~(crypto_tfm_ctx_alignment() - 1);
 425         crypto_aead_set_reqsize(
 426                 tfm,
 427                 align + sizeof(struct crypto_ccm_req_priv_ctx) +
 428                 crypto_skcipher_reqsize(ctr));
 429
 430         return 0;
 431
 432 err_free_mac:
 433         crypto_free_ahash(mac);
 434         return err;
 435 }
 436
 437 static void crypto_ccm_exit_tfm(struct crypto_aead *tfm)
 438 {
 439         struct crypto_ccm_ctx *ctx = crypto_aead_ctx(tfm);
 440
 441         crypto_free_ahash(ctx->mac);
 442         crypto_free_skcipher(ctx->ctr);
 443 }
 444
 445 static void crypto_ccm_free(struct aead_instance *inst)
 446 {
 447         struct ccm_instance_ctx *ctx = aead_instance_ctx(inst);
 448
 449         crypto_drop_ahash(&ctx->mac);
 450         crypto_drop_skcipher(&ctx->ctr);
 451         kfree(inst);
 452 }
 453
 454 static int crypto_ccm_create_common(struct crypto_template *tmpl,
 455                                     struct rtattr **tb,
 456                                     const char *full_name,
 457                                     const char *ctr_name,
 458                                     const char *mac_name)
 459 {
 460         struct crypto_attr_type *algt;
 461         struct aead_instance *inst;
 462         struct skcipher_alg *ctr;
 463         struct crypto_alg *mac_alg;
 464         struct hash_alg_common *mac;
 465         struct ccm_instance_ctx *ictx;
 466         int err;
 467
 468         algt = crypto_get_attr_type(tb);
 469         if (IS_ERR(algt))
 470                 return PTR_ERR(algt);
 471
 472         if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
 473                 return -EINVAL;
 474
 475         mac_alg = crypto_find_alg(mac_name, &crypto_ahash_type,
 476                                   CRYPTO_ALG_TYPE_HASH,
 477                                   CRYPTO_ALG_TYPE_AHASH_MASK |
 478                                   CRYPTO_ALG_ASYNC);
 479         if (IS_ERR(mac_alg))
 480                 return PTR_ERR(mac_alg);
 481
 482         mac = __crypto_hash_alg_common(mac_alg);
 483         err = -EINVAL;
 484         if (mac->digestsize != 16)
 485                 goto out_put_mac;
 486
 487         inst = kzalloc(sizeof(*inst) + sizeof(*ictx), GFP_KERNEL);
 488         err = -ENOMEM;
 489         if (!inst)
 490                 goto out_put_mac;
 491
 492         ictx = aead_instance_ctx(inst);
 493         err = crypto_init_ahash_spawn(&ictx->mac, mac,
 494                                       aead_crypto_instance(inst));
 495         if (err)
 496                 goto err_free_inst;
 497
 498         crypto_set_skcipher_spawn(&ictx->ctr, aead_crypto_instance(inst));
 499         err = crypto_grab_skcipher(&ictx->ctr, ctr_name, 0,
 500                                    crypto_requires_sync(algt->type,
 501                                                         algt->mask));
 502         if (err)
 503                 goto err_drop_mac;
 504
 505         ctr = crypto_spawn_skcipher_alg(&ictx->ctr);
 506
 507         /* Not a stream cipher? */
 508         err = -EINVAL;
 509         if (ctr->base.cra_blocksize != 1)
 510                 goto err_drop_ctr;
 511
 512         /* We want the real thing! */
 513         if (crypto_skcipher_alg_ivsize(ctr) != 16)
 514                 goto err_drop_ctr;
 515
 516         err = -ENAMETOOLONG;
 517         if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
 518                      "ccm_base(%s,%s)", ctr->base.cra_driver_name,
 519                      mac->base.cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
 520                 goto err_drop_ctr;
 521
 522         memcpy(inst->alg.base.cra_name, full_name, CRYPTO_MAX_ALG_NAME);
 523
 524         inst->alg.base.cra_flags = ctr->base.cra_flags & CRYPTO_ALG_ASYNC;
 525         inst->alg.base.cra_priority = (mac->base.cra_priority +
 526                                        ctr->base.cra_priority) / 2;
 527         inst->alg.base.cra_blocksize = 1;
 528         inst->alg.base.cra_alignmask = mac->base.cra_alignmask |
 529                                        ctr->base.cra_alignmask;
 530         inst->alg.ivsize = 16;
 531         inst->alg.chunksize = crypto_skcipher_alg_chunksize(ctr);
 532         inst->alg.maxauthsize = 16;
 533         inst->alg.base.cra_ctxsize = sizeof(struct crypto_ccm_ctx);
 534         inst->alg.init = crypto_ccm_init_tfm;
 535         inst->alg.exit = crypto_ccm_exit_tfm;
 536         inst->alg.setkey = crypto_ccm_setkey;
 537         inst->alg.setauthsize = crypto_ccm_setauthsize;
 538         inst->alg.encrypt = crypto_ccm_encrypt;
 539         inst->alg.decrypt = crypto_ccm_decrypt;
 540
 541         inst->free = crypto_ccm_free;
 542
 543         err = aead_register_instance(tmpl, inst);
 544         if (err)
 545                 goto err_drop_ctr;
 546
 547 out_put_mac:
 548         crypto_mod_put(mac_alg);
 549         return err;
 550
 551 err_drop_ctr:
 552         crypto_drop_skcipher(&ictx->ctr);
 553 err_drop_mac:
 554         crypto_drop_ahash(&ictx->mac);
 555 err_free_inst:
 556         kfree(inst);
 557         goto out_put_mac;
 558 }
 559
 560 static int crypto_ccm_create(struct crypto_template *tmpl, struct rtattr **tb)
 561 {
 562         const char *cipher_name;
 563         char ctr_name[CRYPTO_MAX_ALG_NAME];
 564         char mac_name[CRYPTO_MAX_ALG_NAME];
 565         char full_name[CRYPTO_MAX_ALG_NAME];
 566
 567         cipher_name = crypto_attr_alg_name(tb[1]);
 568         if (IS_ERR(cipher_name))
 569                 return PTR_ERR(cipher_name);
 570
 571         if (snprintf(ctr_name, CRYPTO_MAX_ALG_NAME, "ctr(%s)",
 572                      cipher_name) >= CRYPTO_MAX_ALG_NAME)
 573                 return -ENAMETOOLONG;
 574
 575         if (snprintf(mac_name, CRYPTO_MAX_ALG_NAME, "cbcmac(%s)",
 576                      cipher_name) >= CRYPTO_MAX_ALG_NAME)
 577                 return -ENAMETOOLONG;
 578
 579         if (snprintf(full_name, CRYPTO_MAX_ALG_NAME, "ccm(%s)", cipher_name) >=
 580             CRYPTO_MAX_ALG_NAME)
 581                 return -ENAMETOOLONG;
 582
 583         return crypto_ccm_create_common(tmpl, tb, full_name, ctr_name,
 584                                         mac_name);
 585 }
 586
 587 static struct crypto_template crypto_ccm_tmpl = {
 588         .name = "ccm",
 589         .create = crypto_ccm_create,
 590         .module = THIS_MODULE,
 591 };
 592
 593 static int crypto_ccm_base_create(struct crypto_template *tmpl,
 594                                   struct rtattr **tb)
 595 {
 596         const char *ctr_name;
 597         const char *cipher_name;
 598         char full_name[CRYPTO_MAX_ALG_NAME];
 599
 600         ctr_name = crypto_attr_alg_name(tb[1]);
 601         if (IS_ERR(ctr_name))
 602                 return PTR_ERR(ctr_name);
 603
 604         cipher_name = crypto_attr_alg_name(tb[2]);
 605         if (IS_ERR(cipher_name))
 606                 return PTR_ERR(cipher_name);
 607
 608         if (snprintf(full_name, CRYPTO_MAX_ALG_NAME, "ccm_base(%s,%s)",
 609                      ctr_name, cipher_name) >= CRYPTO_MAX_ALG_NAME)
 610                 return -ENAMETOOLONG;
 611
 612         return crypto_ccm_create_common(tmpl, tb, full_name, ctr_name,
 613                                         cipher_name);
 614 }
 615
 616 static struct crypto_template crypto_ccm_base_tmpl = {
 617         .name = "ccm_base",
 618         .create = crypto_ccm_base_create,
 619         .module = THIS_MODULE,
 620 };
 621
 622 static int crypto_rfc4309_setkey(struct crypto_aead *parent, const u8 *key,
 623                                  unsigned int keylen)
 624 {
 625         struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(parent);
 626         struct crypto_aead *child = ctx->child;
 627         int err;
 628
 629         if (keylen < 3)
 630                 return -EINVAL;
 631
 632         keylen -= 3;
 633         memcpy(ctx->nonce, key + keylen, 3);
 634
 635         crypto_aead_clear_flags(child, CRYPTO_TFM_REQ_MASK);
 636         crypto_aead_set_flags(child, crypto_aead_get_flags(parent) &
 637                                      CRYPTO_TFM_REQ_MASK);
 638         err = crypto_aead_setkey(child, key, keylen);
 639         crypto_aead_set_flags(parent, crypto_aead_get_flags(child) &
 640                                       CRYPTO_TFM_RES_MASK);
 641
 642         return err;
 643 }
 644
 645 static int crypto_rfc4309_setauthsize(struct crypto_aead *parent,
 646                                       unsigned int authsize)
 647 {
 648         struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(parent);
 649
 650         switch (authsize) {
 651         case 8:
 652         case 12:
 653         case 16:
 654                 break;
 655         default:
 656                 return -EINVAL;
 657         }
 658
 659         return crypto_aead_setauthsize(ctx->child, authsize);
 660 }
 661
 662 static struct aead_request *crypto_rfc4309_crypt(struct aead_request *req)
 663 {
 664         struct crypto_rfc4309_req_ctx *rctx = aead_request_ctx(req);
 665         struct aead_request *subreq = &rctx->subreq;
 666         struct crypto_aead *aead = crypto_aead_reqtfm(req);
 667         struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(aead);
 668         struct crypto_aead *child = ctx->child;
 669         struct scatterlist *sg;
 670         u8 *iv = PTR_ALIGN((u8 *)(subreq + 1) + crypto_aead_reqsize(child),
 671                            crypto_aead_alignmask(child) + 1);
 672
 673         /* L' */
 674         iv[0] = 3;
 675
 676         memcpy(iv + 1, ctx->nonce, 3);
 677         memcpy(iv + 4, req->iv, 8);
 678
 679         scatterwalk_map_and_copy(iv + 16, req->src, 0, req->assoclen - 8, 0);
 680
 681         sg_init_table(rctx->src, 3);
 682         sg_set_buf(rctx->src, iv + 16, req->assoclen - 8);
 683         sg = scatterwalk_ffwd(rctx->src + 1, req->src, req->assoclen);
 684         if (sg != rctx->src + 1)
 685                 sg_chain(rctx->src, 2, sg);
 686
 687         if (req->src != req->dst) {
 688                 sg_init_table(rctx->dst, 3);
 689                 sg_set_buf(rctx->dst, iv + 16, req->assoclen - 8);
 690                 sg = scatterwalk_ffwd(rctx->dst + 1, req->dst, req->assoclen);
 691                 if (sg != rctx->dst + 1)
 692                         sg_chain(rctx->dst, 2, sg);
 693         }
 694
 695         aead_request_set_tfm(subreq, child);
 696         aead_request_set_callback(subreq, req->base.flags, req->base.complete,
 697                                   req->base.data);
 698         aead_request_set_crypt(subreq, rctx->src,
 699                                req->src == req->dst ? rctx->src : rctx->dst,
 700                                req->cryptlen, iv);
 701         aead_request_set_ad(subreq, req->assoclen - 8);
 702
 703         return subreq;
 704 }
 705
 706 static int crypto_rfc4309_encrypt(struct aead_request *req)
 707 {
 708         if (req->assoclen != 16 && req->assoclen != 20)
 709                 return -EINVAL;
 710
 711         req = crypto_rfc4309_crypt(req);
 712
 713         return crypto_aead_encrypt(req);
 714 }
 715
 716 static int crypto_rfc4309_decrypt(struct aead_request *req)
 717 {
 718         if (req->assoclen != 16 && req->assoclen != 20)
 719                 return -EINVAL;
 720
 721         req = crypto_rfc4309_crypt(req);
 722
 723         return crypto_aead_decrypt(req);
 724 }
 725
 726 static int crypto_rfc4309_init_tfm(struct crypto_aead *tfm)
 727 {
 728         struct aead_instance *inst = aead_alg_instance(tfm);
 729         struct crypto_aead_spawn *spawn = aead_instance_ctx(inst);
 730         struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(tfm);
 731         struct crypto_aead *aead;
 732         unsigned long align;
 733
 734         aead = crypto_spawn_aead(spawn);
 735         if (IS_ERR(aead))
 736                 return PTR_ERR(aead);
 737
 738         ctx->child = aead;
 739
 740         align = crypto_aead_alignmask(aead);
 741         align &= ~(crypto_tfm_ctx_alignment() - 1);
 742         crypto_aead_set_reqsize(
 743                 tfm,
 744                 sizeof(struct crypto_rfc4309_req_ctx) +
 745                 ALIGN(crypto_aead_reqsize(aead), crypto_tfm_ctx_alignment()) +
 746                 align + 32);
 747
 748         return 0;
 749 }
 750
 751 static void crypto_rfc4309_exit_tfm(struct crypto_aead *tfm)
 752 {
 753         struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(tfm);
 754
 755         crypto_free_aead(ctx->child);
 756 }
 757
 758 static void crypto_rfc4309_free(struct aead_instance *inst)
 759 {
 760         crypto_drop_aead(aead_instance_ctx(inst));
 761         kfree(inst);
 762 }
 763
 764 static int crypto_rfc4309_create(struct crypto_template *tmpl,
 765                                  struct rtattr **tb)
 766 {
 767         struct crypto_attr_type *algt;
 768         struct aead_instance *inst;
 769         struct crypto_aead_spawn *spawn;
 770         struct aead_alg *alg;
 771         const char *ccm_name;
 772         int err;
 773
 774         algt = crypto_get_attr_type(tb);
 775         if (IS_ERR(algt))
 776                 return PTR_ERR(algt);
 777
 778         if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
 779                 return -EINVAL;
 780
 781         ccm_name = crypto_attr_alg_name(tb[1]);
 782         if (IS_ERR(ccm_name))
 783                 return PTR_ERR(ccm_name);
 784
 785         inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
 786         if (!inst)
 787                 return -ENOMEM;
 788
 789         spawn = aead_instance_ctx(inst);
 790         crypto_set_aead_spawn(spawn, aead_crypto_instance(inst));
 791         err = crypto_grab_aead(spawn, ccm_name, 0,
 792                                crypto_requires_sync(algt->type, algt->mask));
 793         if (err)
 794                 goto out_free_inst;
 795
 796         alg = crypto_spawn_aead_alg(spawn);
 797
 798         err = -EINVAL;
 799
 800         /* We only support 16-byte blocks. */
 801         if (crypto_aead_alg_ivsize(alg) != 16)
 802                 goto out_drop_alg;
 803
 804         /* Not a stream cipher? */
 805         if (alg->base.cra_blocksize != 1)
 806                 goto out_drop_alg;
 807
 808         err = -ENAMETOOLONG;
 809         if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
 810                      "rfc4309(%s)", alg->base.cra_name) >=
 811             CRYPTO_MAX_ALG_NAME ||
 812             snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
 813                      "rfc4309(%s)", alg->base.cra_driver_name) >=
 814             CRYPTO_MAX_ALG_NAME)
 815                 goto out_drop_alg;
 816
 817         inst->alg.base.cra_flags = alg->base.cra_flags & CRYPTO_ALG_ASYNC;
 818         inst->alg.base.cra_priority = alg->base.cra_priority;
 819         inst->alg.base.cra_blocksize = 1;
 820         inst->alg.base.cra_alignmask = alg->base.cra_alignmask;
 821
 822         inst->alg.ivsize = 8;
 823         inst->alg.chunksize = crypto_aead_alg_chunksize(alg);
 824         inst->alg.maxauthsize = 16;
 825
 826         inst->alg.base.cra_ctxsize = sizeof(struct crypto_rfc4309_ctx);
 827
 828         inst->alg.init = crypto_rfc4309_init_tfm;
 829         inst->alg.exit = crypto_rfc4309_exit_tfm;
 830
 831         inst->alg.setkey = crypto_rfc4309_setkey;
 832         inst->alg.setauthsize = crypto_rfc4309_setauthsize;
 833         inst->alg.encrypt = crypto_rfc4309_encrypt;
 834         inst->alg.decrypt = crypto_rfc4309_decrypt;
 835
 836         inst->free = crypto_rfc4309_free;
 837
 838         err = aead_register_instance(tmpl, inst);
 839         if (err)
 840                 goto out_drop_alg;
 841
 842 out:
 843         return err;
 844
 845 out_drop_alg:
 846         crypto_drop_aead(spawn);
 847 out_free_inst:
 848         kfree(inst);
 849         goto out;
 850 }
 851
 852 static struct crypto_template crypto_rfc4309_tmpl = {
 853         .name = "rfc4309",
 854         .create = crypto_rfc4309_create,
 855         .module = THIS_MODULE,
 856 };
 857
 858 static int crypto_cbcmac_digest_setkey(struct crypto_shash *parent,
 859                                      const u8 *inkey, unsigned int keylen)
 860 {
 861         struct cbcmac_tfm_ctx *ctx = crypto_shash_ctx(parent);
 862
 863         return crypto_cipher_setkey(ctx->child, inkey, keylen);
 864 }
 865
 866 static int crypto_cbcmac_digest_init(struct shash_desc *pdesc)
 867 {
 868         struct cbcmac_desc_ctx *ctx = shash_desc_ctx(pdesc);
 869         int bs = crypto_shash_digestsize(pdesc->tfm);
 870         u8 *dg = (u8 *)ctx + crypto_shash_descsize(pdesc->tfm) - bs;
 871
 872         ctx->len = 0;
 873         memset(dg, 0, bs);
 874
 875         return 0;
 876 }
 877
 878 static int crypto_cbcmac_digest_update(struct shash_desc *pdesc, const u8 *p,
 879                                        unsigned int len)
 880 {
 881         struct crypto_shash *parent = pdesc->tfm;
 882         struct cbcmac_tfm_ctx *tctx = crypto_shash_ctx(parent);
 883         struct cbcmac_desc_ctx *ctx = shash_desc_ctx(pdesc);
 884         struct crypto_cipher *tfm = tctx->child;
 885         int bs = crypto_shash_digestsize(parent);
 886         u8 *dg = (u8 *)ctx + crypto_shash_descsize(parent) - bs;
 887
 888         while (len > 0) {
 889                 unsigned int l = min(len, bs - ctx->len);
 890
 891                 crypto_xor(dg + ctx->len, p, l);
 892                 ctx->len +=l;
 893                 len -= l;
 894                 p += l;
 895
 896                 if (ctx->len == bs) {
 897                         crypto_cipher_encrypt_one(tfm, dg, dg);
 898                         ctx->len = 0;
 899                 }
 900         }
 901
 902         return 0;
 903 }
 904
 905 static int crypto_cbcmac_digest_final(struct shash_desc *pdesc, u8 *out)
 906 {
 907         struct crypto_shash *parent = pdesc->tfm;
 908         struct cbcmac_tfm_ctx *tctx = crypto_shash_ctx(parent);
 909         struct cbcmac_desc_ctx *ctx = shash_desc_ctx(pdesc);
 910         struct crypto_cipher *tfm = tctx->child;
 911         int bs = crypto_shash_digestsize(parent);
 912         u8 *dg = (u8 *)ctx + crypto_shash_descsize(parent) - bs;
 913
 914         if (ctx->len)
 915                 crypto_cipher_encrypt_one(tfm, dg, dg);
 916
 917         memcpy(out, dg, bs);
 918         return 0;
 919 }
 920
 921 static int cbcmac_init_tfm(struct crypto_tfm *tfm)
 922 {
 923         struct crypto_cipher *cipher;
 924         struct crypto_instance *inst = (void *)tfm->__crt_alg;
 925         struct crypto_spawn *spawn = crypto_instance_ctx(inst);
 926         struct cbcmac_tfm_ctx *ctx = crypto_tfm_ctx(tfm);
 927
 928         cipher = crypto_spawn_cipher(spawn);
 929         if (IS_ERR(cipher))
 930                 return PTR_ERR(cipher);
 931
 932         ctx->child = cipher;
 933
 934         return 0;
 935 };
 936
 937 static void cbcmac_exit_tfm(struct crypto_tfm *tfm)
 938 {
 939         struct cbcmac_tfm_ctx *ctx = crypto_tfm_ctx(tfm);
 940         crypto_free_cipher(ctx->child);
 941 }
 942
 943 static int cbcmac_create(struct crypto_template *tmpl, struct rtattr **tb)
 944 {
 945         struct shash_instance *inst;
 946         struct crypto_alg *alg;
 947         int err;
 948
 949         err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SHASH);
 950         if (err)
 951                 return err;
 952
 953         alg = crypto_get_attr_alg(tb, CRYPTO_ALG_TYPE_CIPHER,
 954                                   CRYPTO_ALG_TYPE_MASK);
 955         if (IS_ERR(alg))
 956                 return PTR_ERR(alg);
 957
 958         inst = shash_alloc_instance("cbcmac", alg);
 959         err = PTR_ERR(inst);
 960         if (IS_ERR(inst))
 961                 goto out_put_alg;
 962
 963         err = crypto_init_spawn(shash_instance_ctx(inst), alg,
 964                                 shash_crypto_instance(inst),
 965                                 CRYPTO_ALG_TYPE_MASK);
 966         if (err)
 967                 goto out_free_inst;
 968
 969         inst->alg.base.cra_priority = alg->cra_priority;
 970         inst->alg.base.cra_blocksize = 1;
 971
 972         inst->alg.digestsize = alg->cra_blocksize;
 973         inst->alg.descsize = ALIGN(sizeof(struct cbcmac_desc_ctx),
 974                                    alg->cra_alignmask + 1) +
 975                              alg->cra_blocksize;
 976
 977         inst->alg.base.cra_ctxsize = sizeof(struct cbcmac_tfm_ctx);
 978         inst->alg.base.cra_init = cbcmac_init_tfm;
 979         inst->alg.base.cra_exit = cbcmac_exit_tfm;
 980
 981         inst->alg.init = crypto_cbcmac_digest_init;
 982         inst->alg.update = crypto_cbcmac_digest_update;
 983         inst->alg.final = crypto_cbcmac_digest_final;
 984         inst->alg.setkey = crypto_cbcmac_digest_setkey;
 985
 986         err = shash_register_instance(tmpl, inst);
 987
 988 out_free_inst:
 989         if (err)
 990                 shash_free_instance(shash_crypto_instance(inst));
 991
 992 out_put_alg:
 993         crypto_mod_put(alg);
 994         return err;
 995 }
 996
 997 static struct crypto_template crypto_cbcmac_tmpl = {
 998         .name = "cbcmac",
 999         .create = cbcmac_create,
1000         .free = shash_free_instance,
1001         .module = THIS_MODULE,
1002 };
1003
1004 static int __init crypto_ccm_module_init(void)
1005 {
1006         int err;
1007
1008         err = crypto_register_template(&crypto_cbcmac_tmpl);
1009         if (err)
1010                 goto out;
1011
1012         err = crypto_register_template(&crypto_ccm_base_tmpl);
1013         if (err)
1014                 goto out_undo_cbcmac;
1015
1016         err = crypto_register_template(&crypto_ccm_tmpl);
1017         if (err)
1018                 goto out_undo_base;
1019
1020         err = crypto_register_template(&crypto_rfc4309_tmpl);
1021         if (err)
1022                 goto out_undo_ccm;
1023
1024 out:
1025         return err;
1026
1027 out_undo_ccm:
1028         crypto_unregister_template(&crypto_ccm_tmpl);
1029 out_undo_base:
1030         crypto_unregister_template(&crypto_ccm_base_tmpl);
1031 out_undo_cbcmac:
1032         crypto_register_template(&crypto_cbcmac_tmpl);
1033         goto out;
1034 }
1035
1036 static void __exit crypto_ccm_module_exit(void)
1037 {
1038         crypto_unregister_template(&crypto_rfc4309_tmpl);
1039         crypto_unregister_template(&crypto_ccm_tmpl);
1040         crypto_unregister_template(&crypto_ccm_base_tmpl);
1041         crypto_unregister_template(&crypto_cbcmac_tmpl);
1042 }
1043
1044 module_init(crypto_ccm_module_init);
1045 module_exit(crypto_ccm_module_exit);
1046
1047 MODULE_LICENSE("GPL");
1048 MODULE_DESCRIPTION("Counter with CBC MAC");
1049 MODULE_ALIAS_CRYPTO("ccm_base");
1050 MODULE_ALIAS_CRYPTO("rfc4309");
1051 MODULE_ALIAS_CRYPTO("ccm");