crypto/ccm.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * CCM: Counter with CBC-MAC
   4  *
   5  * (C) Copyright IBM Corp. 2007 - Joy Latten <latten@us.ibm.com>
   6  */
   7
   8 #include <crypto/internal/aead.h>
   9 #include <crypto/internal/cipher.h>
  10 #include <crypto/internal/hash.h>
  11 #include <crypto/internal/skcipher.h>
  12 #include <crypto/scatterwalk.h>
  13 #include <linux/err.h>
  14 #include <linux/init.h>
  15 #include <linux/kernel.h>
  16 #include <linux/module.h>
  17 #include <linux/slab.h>
  18
  19 struct ccm_instance_ctx {
  20         struct crypto_skcipher_spawn ctr;
  21         struct crypto_ahash_spawn mac;
  22 };
  23
  24 struct crypto_ccm_ctx {
  25         struct crypto_ahash *mac;
  26         struct crypto_skcipher *ctr;
  27 };
  28
  29 struct crypto_rfc4309_ctx {
  30         struct crypto_aead *child;
  31         u8 nonce[3];
  32 };
  33
  34 struct crypto_rfc4309_req_ctx {
  35         struct scatterlist src[3];
  36         struct scatterlist dst[3];
  37         struct aead_request subreq;
  38 };
  39
  40 struct crypto_ccm_req_priv_ctx {
  41         u8 odata[16];
  42         u8 idata[16];
  43         u8 auth_tag[16];
  44         u32 flags;
  45         struct scatterlist src[3];
  46         struct scatterlist dst[3];
  47         union {
  48                 struct ahash_request ahreq;
  49                 struct skcipher_request skreq;
  50         };
  51 };
  52
  53 struct cbcmac_tfm_ctx {
  54         struct crypto_cipher *child;
  55 };
  56
  57 struct cbcmac_desc_ctx {
  58         unsigned int len;
  59 };
  60
  61 static inline struct crypto_ccm_req_priv_ctx *crypto_ccm_reqctx(
  62         struct aead_request *req)
  63 {
  64         unsigned long align = crypto_aead_alignmask(crypto_aead_reqtfm(req));
  65
  66         return (void *)PTR_ALIGN((u8 *)aead_request_ctx(req), align + 1);
  67 }
  68
  69 static int set_msg_len(u8 *block, unsigned int msglen, int csize)
  70 {
  71         __be32 data;
  72
  73         memset(block, 0, csize);
  74         block += csize;
  75
  76         if (csize >= 4)
  77                 csize = 4;
  78         else if (msglen > (1 << (8 * csize)))
  79                 return -EOVERFLOW;
  80
  81         data = cpu_to_be32(msglen);
  82         memcpy(block - csize, (u8 *)&data + 4 - csize, csize);
  83
  84         return 0;
  85 }
  86
  87 static int crypto_ccm_setkey(struct crypto_aead *aead, const u8 *key,
  88                              unsigned int keylen)
  89 {
  90         struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
  91         struct crypto_skcipher *ctr = ctx->ctr;
  92         struct crypto_ahash *mac = ctx->mac;
  93         int err;
  94
  95         crypto_skcipher_clear_flags(ctr, CRYPTO_TFM_REQ_MASK);
  96         crypto_skcipher_set_flags(ctr, crypto_aead_get_flags(aead) &
  97                                        CRYPTO_TFM_REQ_MASK);
  98         err = crypto_skcipher_setkey(ctr, key, keylen);
  99         if (err)
 100                 return err;
 101
 102         crypto_ahash_clear_flags(mac, CRYPTO_TFM_REQ_MASK);
 103         crypto_ahash_set_flags(mac, crypto_aead_get_flags(aead) &
 104                                     CRYPTO_TFM_REQ_MASK);
 105         return crypto_ahash_setkey(mac, key, keylen);
 106 }
 107
 108 static int crypto_ccm_setauthsize(struct crypto_aead *tfm,
 109                                   unsigned int authsize)
 110 {
 111         switch (authsize) {
 112         case 4:
 113         case 6:
 114         case 8:
 115         case 10:
 116         case 12:
 117         case 14:
 118         case 16:
 119                 break;
 120         default:
 121                 return -EINVAL;
 122         }
 123
 124         return 0;
 125 }
 126
 127 static int format_input(u8 *info, struct aead_request *req,
 128                         unsigned int cryptlen)
 129 {
 130         struct crypto_aead *aead = crypto_aead_reqtfm(req);
 131         unsigned int lp = req->iv[0];
 132         unsigned int l = lp + 1;
 133         unsigned int m;
 134
 135         m = crypto_aead_authsize(aead);
 136
 137         memcpy(info, req->iv, 16);
 138
 139         /* format control info per RFC 3610 and
 140          * NIST Special Publication 800-38C
 141          */
 142         *info |= (8 * ((m - 2) / 2));
 143         if (req->assoclen)
 144                 *info |= 64;
 145
 146         return set_msg_len(info + 16 - l, cryptlen, l);
 147 }
 148
 149 static int format_adata(u8 *adata, unsigned int a)
 150 {
 151         int len = 0;
 152
 153         /* add control info for associated data
 154          * RFC 3610 and NIST Special Publication 800-38C
 155          */
 156         if (a < 65280) {
 157                 *(__be16 *)adata = cpu_to_be16(a);
 158                 len = 2;
 159         } else  {
 160                 *(__be16 *)adata = cpu_to_be16(0xfffe);
 161                 *(__be32 *)&adata[2] = cpu_to_be32(a);
 162                 len = 6;
 163         }
 164
 165         return len;
 166 }
 167
 168 static int crypto_ccm_auth(struct aead_request *req, struct scatterlist *plain,
 169                            unsigned int cryptlen)
 170 {
 171         struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
 172         struct crypto_aead *aead = crypto_aead_reqtfm(req);
 173         struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
 174         struct ahash_request *ahreq = &pctx->ahreq;
 175         unsigned int assoclen = req->assoclen;
 176         struct scatterlist sg[3];
 177         u8 *odata = pctx->odata;
 178         u8 *idata = pctx->idata;
 179         int ilen, err;
 180
 181         /* format control data for input */
 182         err = format_input(odata, req, cryptlen);
 183         if (err)
 184                 goto out;
 185
 186         sg_init_table(sg, 3);
 187         sg_set_buf(&sg[0], odata, 16);
 188
 189         /* format associated data and compute into mac */
 190         if (assoclen) {
 191                 ilen = format_adata(idata, assoclen);
 192                 sg_set_buf(&sg[1], idata, ilen);
 193                 sg_chain(sg, 3, req->src);
 194         } else {
 195                 ilen = 0;
 196                 sg_chain(sg, 2, req->src);
 197         }
 198
 199         ahash_request_set_tfm(ahreq, ctx->mac);
 200         ahash_request_set_callback(ahreq, pctx->flags, NULL, NULL);
 201         ahash_request_set_crypt(ahreq, sg, NULL, assoclen + ilen + 16);
 202         err = crypto_ahash_init(ahreq);
 203         if (err)
 204                 goto out;
 205         err = crypto_ahash_update(ahreq);
 206         if (err)
 207                 goto out;
 208
 209         /* we need to pad the MAC input to a round multiple of the block size */
 210         ilen = 16 - (assoclen + ilen) % 16;
 211         if (ilen < 16) {
 212                 memset(idata, 0, ilen);
 213                 sg_init_table(sg, 2);
 214                 sg_set_buf(&sg[0], idata, ilen);
 215                 if (plain)
 216                         sg_chain(sg, 2, plain);
 217                 plain = sg;
 218                 cryptlen += ilen;
 219         }
 220
 221         ahash_request_set_crypt(ahreq, plain, odata, cryptlen);
 222         err = crypto_ahash_finup(ahreq);
 223 out:
 224         return err;
 225 }
 226
 227 static void crypto_ccm_encrypt_done(struct crypto_async_request *areq, int err)
 228 {
 229         struct aead_request *req = areq->data;
 230         struct crypto_aead *aead = crypto_aead_reqtfm(req);
 231         struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
 232         u8 *odata = pctx->odata;
 233
 234         if (!err)
 235                 scatterwalk_map_and_copy(odata, req->dst,
 236                                          req->assoclen + req->cryptlen,
 237                                          crypto_aead_authsize(aead), 1);
 238         aead_request_complete(req, err);
 239 }
 240
 241 static inline int crypto_ccm_check_iv(const u8 *iv)
 242 {
 243         /* 2 <= L <= 8, so 1 <= L' <= 7. */
 244         if (1 > iv[0] || iv[0] > 7)
 245                 return -EINVAL;
 246
 247         return 0;
 248 }
 249
 250 static int crypto_ccm_init_crypt(struct aead_request *req, u8 *tag)
 251 {
 252         struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
 253         struct scatterlist *sg;
 254         u8 *iv = req->iv;
 255         int err;
 256
 257         err = crypto_ccm_check_iv(iv);
 258         if (err)
 259                 return err;
 260
 261         pctx->flags = aead_request_flags(req);
 262
 263          /* Note: rfc 3610 and NIST 800-38C require counter of
 264          * zero to encrypt auth tag.
 265          */
 266         memset(iv + 15 - iv[0], 0, iv[0] + 1);
 267
 268         sg_init_table(pctx->src, 3);
 269         sg_set_buf(pctx->src, tag, 16);
 270         sg = scatterwalk_ffwd(pctx->src + 1, req->src, req->assoclen);
 271         if (sg != pctx->src + 1)
 272                 sg_chain(pctx->src, 2, sg);
 273
 274         if (req->src != req->dst) {
 275                 sg_init_table(pctx->dst, 3);
 276                 sg_set_buf(pctx->dst, tag, 16);
 277                 sg = scatterwalk_ffwd(pctx->dst + 1, req->dst, req->assoclen);
 278                 if (sg != pctx->dst + 1)
 279                         sg_chain(pctx->dst, 2, sg);
 280         }
 281
 282         return 0;
 283 }
 284
 285 static int crypto_ccm_encrypt(struct aead_request *req)
 286 {
 287         struct crypto_aead *aead = crypto_aead_reqtfm(req);
 288         struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
 289         struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
 290         struct skcipher_request *skreq = &pctx->skreq;
 291         struct scatterlist *dst;
 292         unsigned int cryptlen = req->cryptlen;
 293         u8 *odata = pctx->odata;
 294         u8 *iv = req->iv;
 295         int err;
 296
 297         err = crypto_ccm_init_crypt(req, odata);
 298         if (err)
 299                 return err;
 300
 301         err = crypto_ccm_auth(req, sg_next(pctx->src), cryptlen);
 302         if (err)
 303                 return err;
 304
 305         dst = pctx->src;
 306         if (req->src != req->dst)
 307                 dst = pctx->dst;
 308
 309         skcipher_request_set_tfm(skreq, ctx->ctr);
 310         skcipher_request_set_callback(skreq, pctx->flags,
 311                                       crypto_ccm_encrypt_done, req);
 312         skcipher_request_set_crypt(skreq, pctx->src, dst, cryptlen + 16, iv);
 313         err = crypto_skcipher_encrypt(skreq);
 314         if (err)
 315                 return err;
 316
 317         /* copy authtag to end of dst */
 318         scatterwalk_map_and_copy(odata, sg_next(dst), cryptlen,
 319                                  crypto_aead_authsize(aead), 1);
 320         return err;
 321 }
 322
 323 static void crypto_ccm_decrypt_done(struct crypto_async_request *areq,
 324                                    int err)
 325 {
 326         struct aead_request *req = areq->data;
 327         struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
 328         struct crypto_aead *aead = crypto_aead_reqtfm(req);
 329         unsigned int authsize = crypto_aead_authsize(aead);
 330         unsigned int cryptlen = req->cryptlen - authsize;
 331         struct scatterlist *dst;
 332
 333         pctx->flags = 0;
 334
 335         dst = sg_next(req->src == req->dst ? pctx->src : pctx->dst);
 336
 337         if (!err) {
 338                 err = crypto_ccm_auth(req, dst, cryptlen);
 339                 if (!err && crypto_memneq(pctx->auth_tag, pctx->odata, authsize))
 340                         err = -EBADMSG;
 341         }
 342         aead_request_complete(req, err);
 343 }
 344
 345 static int crypto_ccm_decrypt(struct aead_request *req)
 346 {
 347         struct crypto_aead *aead = crypto_aead_reqtfm(req);
 348         struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
 349         struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
 350         struct skcipher_request *skreq = &pctx->skreq;
 351         struct scatterlist *dst;
 352         unsigned int authsize = crypto_aead_authsize(aead);
 353         unsigned int cryptlen = req->cryptlen;
 354         u8 *authtag = pctx->auth_tag;
 355         u8 *odata = pctx->odata;
 356         u8 *iv = pctx->idata;
 357         int err;
 358
 359         cryptlen -= authsize;
 360
 361         err = crypto_ccm_init_crypt(req, authtag);
 362         if (err)
 363                 return err;
 364
 365         scatterwalk_map_and_copy(authtag, sg_next(pctx->src), cryptlen,
 366                                  authsize, 0);
 367
 368         dst = pctx->src;
 369         if (req->src != req->dst)
 370                 dst = pctx->dst;
 371
 372         memcpy(iv, req->iv, 16);
 373
 374         skcipher_request_set_tfm(skreq, ctx->ctr);
 375         skcipher_request_set_callback(skreq, pctx->flags,
 376                                       crypto_ccm_decrypt_done, req);
 377         skcipher_request_set_crypt(skreq, pctx->src, dst, cryptlen + 16, iv);
 378         err = crypto_skcipher_decrypt(skreq);
 379         if (err)
 380                 return err;
 381
 382         err = crypto_ccm_auth(req, sg_next(dst), cryptlen);
 383         if (err)
 384                 return err;
 385
 386         /* verify */
 387         if (crypto_memneq(authtag, odata, authsize))
 388                 return -EBADMSG;
 389
 390         return err;
 391 }
 392
 393 static int crypto_ccm_init_tfm(struct crypto_aead *tfm)
 394 {
 395         struct aead_instance *inst = aead_alg_instance(tfm);
 396         struct ccm_instance_ctx *ictx = aead_instance_ctx(inst);
 397         struct crypto_ccm_ctx *ctx = crypto_aead_ctx(tfm);
 398         struct crypto_ahash *mac;
 399         struct crypto_skcipher *ctr;
 400         unsigned long align;
 401         int err;
 402
 403         mac = crypto_spawn_ahash(&ictx->mac);
 404         if (IS_ERR(mac))
 405                 return PTR_ERR(mac);
 406
 407         ctr = crypto_spawn_skcipher(&ictx->ctr);
 408         err = PTR_ERR(ctr);
 409         if (IS_ERR(ctr))
 410                 goto err_free_mac;
 411
 412         ctx->mac = mac;
 413         ctx->ctr = ctr;
 414
 415         align = crypto_aead_alignmask(tfm);
 416         align &= ~(crypto_tfm_ctx_alignment() - 1);
 417         crypto_aead_set_reqsize(
 418                 tfm,
 419                 align + sizeof(struct crypto_ccm_req_priv_ctx) +
 420                 max(crypto_ahash_reqsize(mac), crypto_skcipher_reqsize(ctr)));
 421
 422         return 0;
 423
 424 err_free_mac:
 425         crypto_free_ahash(mac);
 426         return err;
 427 }
 428
 429 static void crypto_ccm_exit_tfm(struct crypto_aead *tfm)
 430 {
 431         struct crypto_ccm_ctx *ctx = crypto_aead_ctx(tfm);
 432
 433         crypto_free_ahash(ctx->mac);
 434         crypto_free_skcipher(ctx->ctr);
 435 }
 436
 437 static void crypto_ccm_free(struct aead_instance *inst)
 438 {
 439         struct ccm_instance_ctx *ctx = aead_instance_ctx(inst);
 440
 441         crypto_drop_ahash(&ctx->mac);
 442         crypto_drop_skcipher(&ctx->ctr);
 443         kfree(inst);
 444 }
 445
 446 static int crypto_ccm_create_common(struct crypto_template *tmpl,
 447                                     struct rtattr **tb,
 448                                     const char *ctr_name,
 449                                     const char *mac_name)
 450 {
 451         u32 mask;
 452         struct aead_instance *inst;
 453         struct ccm_instance_ctx *ictx;
 454         struct skcipher_alg *ctr;
 455         struct hash_alg_common *mac;
 456         int err;
 457
 458         err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_AEAD, &mask);
 459         if (err)
 460                 return err;
 461
 462         inst = kzalloc(sizeof(*inst) + sizeof(*ictx), GFP_KERNEL);
 463         if (!inst)
 464                 return -ENOMEM;
 465         ictx = aead_instance_ctx(inst);
 466
 467         err = crypto_grab_ahash(&ictx->mac, aead_crypto_instance(inst),
 468                                 mac_name, 0, mask | CRYPTO_ALG_ASYNC);
 469         if (err)
 470                 goto err_free_inst;
 471         mac = crypto_spawn_ahash_alg(&ictx->mac);
 472
 473         err = -EINVAL;
 474         if (strncmp(mac->base.cra_name, "cbcmac(", 7) != 0 ||
 475             mac->digestsize != 16)
 476                 goto err_free_inst;
 477
 478         err = crypto_grab_skcipher(&ictx->ctr, aead_crypto_instance(inst),
 479                                    ctr_name, 0, mask);
 480         if (err)
 481                 goto err_free_inst;
 482         ctr = crypto_spawn_skcipher_alg(&ictx->ctr);
 483
 484         /* The skcipher algorithm must be CTR mode, using 16-byte blocks. */
 485         err = -EINVAL;
 486         if (strncmp(ctr->base.cra_name, "ctr(", 4) != 0 ||
 487             crypto_skcipher_alg_ivsize(ctr) != 16 ||
 488             ctr->base.cra_blocksize != 1)
 489                 goto err_free_inst;
 490
 491         /* ctr and cbcmac must use the same underlying block cipher. */
 492         if (strcmp(ctr->base.cra_name + 4, mac->base.cra_name + 7) != 0)
 493                 goto err_free_inst;
 494
 495         err = -ENAMETOOLONG;
 496         if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
 497                      "ccm(%s", ctr->base.cra_name + 4) >= CRYPTO_MAX_ALG_NAME)
 498                 goto err_free_inst;
 499
 500         if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
 501                      "ccm_base(%s,%s)", ctr->base.cra_driver_name,
 502                      mac->base.cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
 503                 goto err_free_inst;
 504
 505         inst->alg.base.cra_priority = (mac->base.cra_priority +
 506                                        ctr->base.cra_priority) / 2;
 507         inst->alg.base.cra_blocksize = 1;
 508         inst->alg.base.cra_alignmask = mac->base.cra_alignmask |
 509                                        ctr->base.cra_alignmask;
 510         inst->alg.ivsize = 16;
 511         inst->alg.chunksize = crypto_skcipher_alg_chunksize(ctr);
 512         inst->alg.maxauthsize = 16;
 513         inst->alg.base.cra_ctxsize = sizeof(struct crypto_ccm_ctx);
 514         inst->alg.init = crypto_ccm_init_tfm;
 515         inst->alg.exit = crypto_ccm_exit_tfm;
 516         inst->alg.setkey = crypto_ccm_setkey;
 517         inst->alg.setauthsize = crypto_ccm_setauthsize;
 518         inst->alg.encrypt = crypto_ccm_encrypt;
 519         inst->alg.decrypt = crypto_ccm_decrypt;
 520
 521         inst->free = crypto_ccm_free;
 522
 523         err = aead_register_instance(tmpl, inst);
 524         if (err) {
 525 err_free_inst:
 526                 crypto_ccm_free(inst);
 527         }
 528         return err;
 529 }
 530
 531 static int crypto_ccm_create(struct crypto_template *tmpl, struct rtattr **tb)
 532 {
 533         const char *cipher_name;
 534         char ctr_name[CRYPTO_MAX_ALG_NAME];
 535         char mac_name[CRYPTO_MAX_ALG_NAME];
 536
 537         cipher_name = crypto_attr_alg_name(tb[1]);
 538         if (IS_ERR(cipher_name))
 539                 return PTR_ERR(cipher_name);
 540
 541         if (snprintf(ctr_name, CRYPTO_MAX_ALG_NAME, "ctr(%s)",
 542                      cipher_name) >= CRYPTO_MAX_ALG_NAME)
 543                 return -ENAMETOOLONG;
 544
 545         if (snprintf(mac_name, CRYPTO_MAX_ALG_NAME, "cbcmac(%s)",
 546                      cipher_name) >= CRYPTO_MAX_ALG_NAME)
 547                 return -ENAMETOOLONG;
 548
 549         return crypto_ccm_create_common(tmpl, tb, ctr_name, mac_name);
 550 }
 551
 552 static int crypto_ccm_base_create(struct crypto_template *tmpl,
 553                                   struct rtattr **tb)
 554 {
 555         const char *ctr_name;
 556         const char *mac_name;
 557
 558         ctr_name = crypto_attr_alg_name(tb[1]);
 559         if (IS_ERR(ctr_name))
 560                 return PTR_ERR(ctr_name);
 561
 562         mac_name = crypto_attr_alg_name(tb[2]);
 563         if (IS_ERR(mac_name))
 564                 return PTR_ERR(mac_name);
 565
 566         return crypto_ccm_create_common(tmpl, tb, ctr_name, mac_name);
 567 }
 568
 569 static int crypto_rfc4309_setkey(struct crypto_aead *parent, const u8 *key,
 570                                  unsigned int keylen)
 571 {
 572         struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(parent);
 573         struct crypto_aead *child = ctx->child;
 574
 575         if (keylen < 3)
 576                 return -EINVAL;
 577
 578         keylen -= 3;
 579         memcpy(ctx->nonce, key + keylen, 3);
 580
 581         crypto_aead_clear_flags(child, CRYPTO_TFM_REQ_MASK);
 582         crypto_aead_set_flags(child, crypto_aead_get_flags(parent) &
 583                                      CRYPTO_TFM_REQ_MASK);
 584         return crypto_aead_setkey(child, key, keylen);
 585 }
 586
 587 static int crypto_rfc4309_setauthsize(struct crypto_aead *parent,
 588                                       unsigned int authsize)
 589 {
 590         struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(parent);
 591
 592         switch (authsize) {
 593         case 8:
 594         case 12:
 595         case 16:
 596                 break;
 597         default:
 598                 return -EINVAL;
 599         }
 600
 601         return crypto_aead_setauthsize(ctx->child, authsize);
 602 }
 603
 604 static struct aead_request *crypto_rfc4309_crypt(struct aead_request *req)
 605 {
 606         struct crypto_rfc4309_req_ctx *rctx = aead_request_ctx(req);
 607         struct aead_request *subreq = &rctx->subreq;
 608         struct crypto_aead *aead = crypto_aead_reqtfm(req);
 609         struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(aead);
 610         struct crypto_aead *child = ctx->child;
 611         struct scatterlist *sg;
 612         u8 *iv = PTR_ALIGN((u8 *)(subreq + 1) + crypto_aead_reqsize(child),
 613                            crypto_aead_alignmask(child) + 1);
 614
 615         /* L' */
 616         iv[0] = 3;
 617
 618         memcpy(iv + 1, ctx->nonce, 3);
 619         memcpy(iv + 4, req->iv, 8);
 620
 621         scatterwalk_map_and_copy(iv + 16, req->src, 0, req->assoclen - 8, 0);
 622
 623         sg_init_table(rctx->src, 3);
 624         sg_set_buf(rctx->src, iv + 16, req->assoclen - 8);
 625         sg = scatterwalk_ffwd(rctx->src + 1, req->src, req->assoclen);
 626         if (sg != rctx->src + 1)
 627                 sg_chain(rctx->src, 2, sg);
 628
 629         if (req->src != req->dst) {
 630                 sg_init_table(rctx->dst, 3);
 631                 sg_set_buf(rctx->dst, iv + 16, req->assoclen - 8);
 632                 sg = scatterwalk_ffwd(rctx->dst + 1, req->dst, req->assoclen);
 633                 if (sg != rctx->dst + 1)
 634                         sg_chain(rctx->dst, 2, sg);
 635         }
 636
 637         aead_request_set_tfm(subreq, child);
 638         aead_request_set_callback(subreq, req->base.flags, req->base.complete,
 639                                   req->base.data);
 640         aead_request_set_crypt(subreq, rctx->src,
 641                                req->src == req->dst ? rctx->src : rctx->dst,
 642                                req->cryptlen, iv);
 643         aead_request_set_ad(subreq, req->assoclen - 8);
 644
 645         return subreq;
 646 }
 647
 648 static int crypto_rfc4309_encrypt(struct aead_request *req)
 649 {
 650         if (req->assoclen != 16 && req->assoclen != 20)
 651                 return -EINVAL;
 652
 653         req = crypto_rfc4309_crypt(req);
 654
 655         return crypto_aead_encrypt(req);
 656 }
 657
 658 static int crypto_rfc4309_decrypt(struct aead_request *req)
 659 {
 660         if (req->assoclen != 16 && req->assoclen != 20)
 661                 return -EINVAL;
 662
 663         req = crypto_rfc4309_crypt(req);
 664
 665         return crypto_aead_decrypt(req);
 666 }
 667
 668 static int crypto_rfc4309_init_tfm(struct crypto_aead *tfm)
 669 {
 670         struct aead_instance *inst = aead_alg_instance(tfm);
 671         struct crypto_aead_spawn *spawn = aead_instance_ctx(inst);
 672         struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(tfm);
 673         struct crypto_aead *aead;
 674         unsigned long align;
 675
 676         aead = crypto_spawn_aead(spawn);
 677         if (IS_ERR(aead))
 678                 return PTR_ERR(aead);
 679
 680         ctx->child = aead;
 681
 682         align = crypto_aead_alignmask(aead);
 683         align &= ~(crypto_tfm_ctx_alignment() - 1);
 684         crypto_aead_set_reqsize(
 685                 tfm,
 686                 sizeof(struct crypto_rfc4309_req_ctx) +
 687                 ALIGN(crypto_aead_reqsize(aead), crypto_tfm_ctx_alignment()) +
 688                 align + 32);
 689
 690         return 0;
 691 }
 692
 693 static void crypto_rfc4309_exit_tfm(struct crypto_aead *tfm)
 694 {
 695         struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(tfm);
 696
 697         crypto_free_aead(ctx->child);
 698 }
 699
 700 static void crypto_rfc4309_free(struct aead_instance *inst)
 701 {
 702         crypto_drop_aead(aead_instance_ctx(inst));
 703         kfree(inst);
 704 }
 705
 706 static int crypto_rfc4309_create(struct crypto_template *tmpl,
 707                                  struct rtattr **tb)
 708 {
 709         u32 mask;
 710         struct aead_instance *inst;
 711         struct crypto_aead_spawn *spawn;
 712         struct aead_alg *alg;
 713         int err;
 714
 715         err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_AEAD, &mask);
 716         if (err)
 717                 return err;
 718
 719         inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
 720         if (!inst)
 721                 return -ENOMEM;
 722
 723         spawn = aead_instance_ctx(inst);
 724         err = crypto_grab_aead(spawn, aead_crypto_instance(inst),
 725                                crypto_attr_alg_name(tb[1]), 0, mask);
 726         if (err)
 727                 goto err_free_inst;
 728
 729         alg = crypto_spawn_aead_alg(spawn);
 730
 731         err = -EINVAL;
 732
 733         /* We only support 16-byte blocks. */
 734         if (crypto_aead_alg_ivsize(alg) != 16)
 735                 goto err_free_inst;
 736
 737         /* Not a stream cipher? */
 738         if (alg->base.cra_blocksize != 1)
 739                 goto err_free_inst;
 740
 741         err = -ENAMETOOLONG;
 742         if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
 743                      "rfc4309(%s)", alg->base.cra_name) >=
 744             CRYPTO_MAX_ALG_NAME ||
 745             snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
 746                      "rfc4309(%s)", alg->base.cra_driver_name) >=
 747             CRYPTO_MAX_ALG_NAME)
 748                 goto err_free_inst;
 749
 750         inst->alg.base.cra_priority = alg->base.cra_priority;
 751         inst->alg.base.cra_blocksize = 1;
 752         inst->alg.base.cra_alignmask = alg->base.cra_alignmask;
 753
 754         inst->alg.ivsize = 8;
 755         inst->alg.chunksize = crypto_aead_alg_chunksize(alg);
 756         inst->alg.maxauthsize = 16;
 757
 758         inst->alg.base.cra_ctxsize = sizeof(struct crypto_rfc4309_ctx);
 759
 760         inst->alg.init = crypto_rfc4309_init_tfm;
 761         inst->alg.exit = crypto_rfc4309_exit_tfm;
 762
 763         inst->alg.setkey = crypto_rfc4309_setkey;
 764         inst->alg.setauthsize = crypto_rfc4309_setauthsize;
 765         inst->alg.encrypt = crypto_rfc4309_encrypt;
 766         inst->alg.decrypt = crypto_rfc4309_decrypt;
 767
 768         inst->free = crypto_rfc4309_free;
 769
 770         err = aead_register_instance(tmpl, inst);
 771         if (err) {
 772 err_free_inst:
 773                 crypto_rfc4309_free(inst);
 774         }
 775         return err;
 776 }
 777
 778 static int crypto_cbcmac_digest_setkey(struct crypto_shash *parent,
 779                                      const u8 *inkey, unsigned int keylen)
 780 {
 781         struct cbcmac_tfm_ctx *ctx = crypto_shash_ctx(parent);
 782
 783         return crypto_cipher_setkey(ctx->child, inkey, keylen);
 784 }
 785
 786 static int crypto_cbcmac_digest_init(struct shash_desc *pdesc)
 787 {
 788         struct cbcmac_desc_ctx *ctx = shash_desc_ctx(pdesc);
 789         int bs = crypto_shash_digestsize(pdesc->tfm);
 790         u8 *dg = (u8 *)ctx + crypto_shash_descsize(pdesc->tfm) - bs;
 791
 792         ctx->len = 0;
 793         memset(dg, 0, bs);
 794
 795         return 0;
 796 }
 797
 798 static int crypto_cbcmac_digest_update(struct shash_desc *pdesc, const u8 *p,
 799                                        unsigned int len)
 800 {
 801         struct crypto_shash *parent = pdesc->tfm;
 802         struct cbcmac_tfm_ctx *tctx = crypto_shash_ctx(parent);
 803         struct cbcmac_desc_ctx *ctx = shash_desc_ctx(pdesc);
 804         struct crypto_cipher *tfm = tctx->child;
 805         int bs = crypto_shash_digestsize(parent);
 806         u8 *dg = (u8 *)ctx + crypto_shash_descsize(parent) - bs;
 807
 808         while (len > 0) {
 809                 unsigned int l = min(len, bs - ctx->len);
 810
 811                 crypto_xor(dg + ctx->len, p, l);
 812                 ctx->len +=l;
 813                 len -= l;
 814                 p += l;
 815
 816                 if (ctx->len == bs) {
 817                         crypto_cipher_encrypt_one(tfm, dg, dg);
 818                         ctx->len = 0;
 819                 }
 820         }
 821
 822         return 0;
 823 }
 824
 825 static int crypto_cbcmac_digest_final(struct shash_desc *pdesc, u8 *out)
 826 {
 827         struct crypto_shash *parent = pdesc->tfm;
 828         struct cbcmac_tfm_ctx *tctx = crypto_shash_ctx(parent);
 829         struct cbcmac_desc_ctx *ctx = shash_desc_ctx(pdesc);
 830         struct crypto_cipher *tfm = tctx->child;
 831         int bs = crypto_shash_digestsize(parent);
 832         u8 *dg = (u8 *)ctx + crypto_shash_descsize(parent) - bs;
 833
 834         if (ctx->len)
 835                 crypto_cipher_encrypt_one(tfm, dg, dg);
 836
 837         memcpy(out, dg, bs);
 838         return 0;
 839 }
 840
 841 static int cbcmac_init_tfm(struct crypto_tfm *tfm)
 842 {
 843         struct crypto_cipher *cipher;
 844         struct crypto_instance *inst = (void *)tfm->__crt_alg;
 845         struct crypto_cipher_spawn *spawn = crypto_instance_ctx(inst);
 846         struct cbcmac_tfm_ctx *ctx = crypto_tfm_ctx(tfm);
 847
 848         cipher = crypto_spawn_cipher(spawn);
 849         if (IS_ERR(cipher))
 850                 return PTR_ERR(cipher);
 851
 852         ctx->child = cipher;
 853
 854         return 0;
 855 };
 856
 857 static void cbcmac_exit_tfm(struct crypto_tfm *tfm)
 858 {
 859         struct cbcmac_tfm_ctx *ctx = crypto_tfm_ctx(tfm);
 860         crypto_free_cipher(ctx->child);
 861 }
 862
 863 static int cbcmac_create(struct crypto_template *tmpl, struct rtattr **tb)
 864 {
 865         struct shash_instance *inst;
 866         struct crypto_cipher_spawn *spawn;
 867         struct crypto_alg *alg;
 868         u32 mask;
 869         int err;
 870
 871         err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SHASH, &mask);
 872         if (err)
 873                 return err;
 874
 875         inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
 876         if (!inst)
 877                 return -ENOMEM;
 878         spawn = shash_instance_ctx(inst);
 879
 880         err = crypto_grab_cipher(spawn, shash_crypto_instance(inst),
 881                                  crypto_attr_alg_name(tb[1]), 0, mask);
 882         if (err)
 883                 goto err_free_inst;
 884         alg = crypto_spawn_cipher_alg(spawn);
 885
 886         err = crypto_inst_setname(shash_crypto_instance(inst), tmpl->name, alg);
 887         if (err)
 888                 goto err_free_inst;
 889
 890         inst->alg.base.cra_priority = alg->cra_priority;
 891         inst->alg.base.cra_blocksize = 1;
 892
 893         inst->alg.digestsize = alg->cra_blocksize;
 894         inst->alg.descsize = ALIGN(sizeof(struct cbcmac_desc_ctx),
 895                                    alg->cra_alignmask + 1) +
 896                              alg->cra_blocksize;
 897
 898         inst->alg.base.cra_ctxsize = sizeof(struct cbcmac_tfm_ctx);
 899         inst->alg.base.cra_init = cbcmac_init_tfm;
 900         inst->alg.base.cra_exit = cbcmac_exit_tfm;
 901
 902         inst->alg.init = crypto_cbcmac_digest_init;
 903         inst->alg.update = crypto_cbcmac_digest_update;
 904         inst->alg.final = crypto_cbcmac_digest_final;
 905         inst->alg.setkey = crypto_cbcmac_digest_setkey;
 906
 907         inst->free = shash_free_singlespawn_instance;
 908
 909         err = shash_register_instance(tmpl, inst);
 910         if (err) {
 911 err_free_inst:
 912                 shash_free_singlespawn_instance(inst);
 913         }
 914         return err;
 915 }
 916
 917 static struct crypto_template crypto_ccm_tmpls[] = {
 918         {
 919                 .name = "cbcmac",
 920                 .create = cbcmac_create,
 921                 .module = THIS_MODULE,
 922         }, {
 923                 .name = "ccm_base",
 924                 .create = crypto_ccm_base_create,
 925                 .module = THIS_MODULE,
 926         }, {
 927                 .name = "ccm",
 928                 .create = crypto_ccm_create,
 929                 .module = THIS_MODULE,
 930         }, {
 931                 .name = "rfc4309",
 932                 .create = crypto_rfc4309_create,
 933                 .module = THIS_MODULE,
 934         },
 935 };
 936
 937 static int __init crypto_ccm_module_init(void)
 938 {
 939         return crypto_register_templates(crypto_ccm_tmpls,
 940                                          ARRAY_SIZE(crypto_ccm_tmpls));
 941 }
 942
 943 static void __exit crypto_ccm_module_exit(void)
 944 {
 945         crypto_unregister_templates(crypto_ccm_tmpls,
 946                                     ARRAY_SIZE(crypto_ccm_tmpls));
 947 }
 948
 949 subsys_initcall(crypto_ccm_module_init);
 950 module_exit(crypto_ccm_module_exit);
 951
 952 MODULE_LICENSE("GPL");
 953 MODULE_DESCRIPTION("Counter with CBC MAC");
 954 MODULE_ALIAS_CRYPTO("ccm_base");
 955 MODULE_ALIAS_CRYPTO("rfc4309");
 956 MODULE_ALIAS_CRYPTO("ccm");
 957 MODULE_ALIAS_CRYPTO("cbcmac");
 958 MODULE_IMPORT_NS(CRYPTO_INTERNAL);