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