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/hash.h>
  10 #include <crypto/internal/skcipher.h>
  11 #include <crypto/scatterwalk.h>
  12 #include <linux/err.h>
  13 #include <linux/init.h>
  14 #include <linux/kernel.h>
  15 #include <linux/module.h>
  16 #include <linux/slab.h>
  17
  18 struct ccm_instance_ctx {
  19         struct crypto_skcipher_spawn ctr;
  20         struct crypto_ahash_spawn mac;
  21 };
  22
  23 struct crypto_ccm_ctx {
  24         struct crypto_ahash *mac;
  25         struct crypto_skcipher *ctr;
  26 };
  27
  28 struct crypto_rfc4309_ctx {
  29         struct crypto_aead *child;
  30         u8 nonce[3];
  31 };
  32
  33 struct crypto_rfc4309_req_ctx {
  34         struct scatterlist src[3];
  35         struct scatterlist dst[3];
  36         struct aead_request subreq;
  37 };
  38
  39 struct crypto_ccm_req_priv_ctx {
  40         u8 odata[16];
  41         u8 idata[16];
  42         u8 auth_tag[16];
  43         u32 flags;
  44         struct scatterlist src[3];
  45         struct scatterlist dst[3];
  46         union {
  47                 struct ahash_request ahreq;
  48                 struct skcipher_request skreq;
  49         };
  50 };
  51
  52 struct cbcmac_tfm_ctx {
  53         struct crypto_cipher *child;
  54 };
  55
  56 struct cbcmac_desc_ctx {
  57         unsigned int len;
  58 };
  59
  60 static inline struct crypto_ccm_req_priv_ctx *crypto_ccm_reqctx(
  61         struct aead_request *req)
  62 {
  63         unsigned long align = crypto_aead_alignmask(crypto_aead_reqtfm(req));
  64
  65         return (void *)PTR_ALIGN((u8 *)aead_request_ctx(req), align + 1);
  66 }
  67
  68 static int set_msg_len(u8 *block, unsigned int msglen, int csize)
  69 {
  70         __be32 data;
  71
  72         memset(block, 0, csize);
  73         block += csize;
  74
  75         if (csize >= 4)
  76                 csize = 4;
  77         else if (msglen > (1 << (8 * csize)))
  78                 return -EOVERFLOW;
  79
  80         data = cpu_to_be32(msglen);
  81         memcpy(block - csize, (u8 *)&data + 4 - csize, csize);
  82
  83         return 0;
  84 }
  85
  86 static int crypto_ccm_setkey(struct crypto_aead *aead, const u8 *key,
  87                              unsigned int keylen)
  88 {
  89         struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
  90         struct crypto_skcipher *ctr = ctx->ctr;
  91         struct crypto_ahash *mac = ctx->mac;
  92         int err;
  93
  94         crypto_skcipher_clear_flags(ctr, CRYPTO_TFM_REQ_MASK);
  95         crypto_skcipher_set_flags(ctr, crypto_aead_get_flags(aead) &
  96                                        CRYPTO_TFM_REQ_MASK);
  97         err = crypto_skcipher_setkey(ctr, key, keylen);
  98         if (err)
  99                 return err;
 100
 101         crypto_ahash_clear_flags(mac, CRYPTO_TFM_REQ_MASK);
 102         crypto_ahash_set_flags(mac, crypto_aead_get_flags(aead) &
 103                                     CRYPTO_TFM_REQ_MASK);
 104         return crypto_ahash_setkey(mac, key, keylen);
 105 }
 106
 107 static int crypto_ccm_setauthsize(struct crypto_aead *tfm,
 108                                   unsigned int authsize)
 109 {
 110         switch (authsize) {
 111         case 4:
 112         case 6:
 113         case 8:
 114         case 10:
 115         case 12:
 116         case 14:
 117         case 16:
 118                 break;
 119         default:
 120                 return -EINVAL;
 121         }
 122
 123         return 0;
 124 }
 125
 126 static int format_input(u8 *info, struct aead_request *req,
 127                         unsigned int cryptlen)
 128 {
 129         struct crypto_aead *aead = crypto_aead_reqtfm(req);
 130         unsigned int lp = req->iv[0];
 131         unsigned int l = lp + 1;
 132         unsigned int m;
 133
 134         m = crypto_aead_authsize(aead);
 135
 136         memcpy(info, req->iv, 16);
 137
 138         /* format control info per RFC 3610 and
 139          * NIST Special Publication 800-38C
 140          */
 141         *info |= (8 * ((m - 2) / 2));
 142         if (req->assoclen)
 143                 *info |= 64;
 144
 145         return set_msg_len(info + 16 - l, cryptlen, l);
 146 }
 147
 148 static int format_adata(u8 *adata, unsigned int a)
 149 {
 150         int len = 0;
 151
 152         /* add control info for associated data
 153          * RFC 3610 and NIST Special Publication 800-38C
 154          */
 155         if (a < 65280) {
 156                 *(__be16 *)adata = cpu_to_be16(a);
 157                 len = 2;
 158         } else  {
 159                 *(__be16 *)adata = cpu_to_be16(0xfffe);
 160                 *(__be32 *)&adata[2] = cpu_to_be32(a);
 161                 len = 6;
 162         }
 163
 164         return len;
 165 }
 166
 167 static int crypto_ccm_auth(struct aead_request *req, struct scatterlist *plain,
 168                            unsigned int cryptlen)
 169 {
 170         struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
 171         struct crypto_aead *aead = crypto_aead_reqtfm(req);
 172         struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
 173         struct ahash_request *ahreq = &pctx->ahreq;
 174         unsigned int assoclen = req->assoclen;
 175         struct scatterlist sg[3];
 176         u8 *odata = pctx->odata;
 177         u8 *idata = pctx->idata;
 178         int ilen, err;
 179
 180         /* format control data for input */
 181         err = format_input(odata, req, cryptlen);
 182         if (err)
 183                 goto out;
 184
 185         sg_init_table(sg, 3);
 186         sg_set_buf(&sg[0], odata, 16);
 187
 188         /* format associated data and compute into mac */
 189         if (assoclen) {
 190                 ilen = format_adata(idata, assoclen);
 191                 sg_set_buf(&sg[1], idata, ilen);
 192                 sg_chain(sg, 3, req->src);
 193         } else {
 194                 ilen = 0;
 195                 sg_chain(sg, 2, req->src);
 196         }
 197
 198         ahash_request_set_tfm(ahreq, ctx->mac);
 199         ahash_request_set_callback(ahreq, pctx->flags, NULL, NULL);
 200         ahash_request_set_crypt(ahreq, sg, NULL, assoclen + ilen + 16);
 201         err = crypto_ahash_init(ahreq);
 202         if (err)
 203                 goto out;
 204         err = crypto_ahash_update(ahreq);
 205         if (err)
 206                 goto out;
 207
 208         /* we need to pad the MAC input to a round multiple of the block size */
 209         ilen = 16 - (assoclen + ilen) % 16;
 210         if (ilen < 16) {
 211                 memset(idata, 0, ilen);
 212                 sg_init_table(sg, 2);
 213                 sg_set_buf(&sg[0], idata, ilen);
 214                 if (plain)
 215                         sg_chain(sg, 2, plain);
 216                 plain = sg;
 217                 cryptlen += ilen;
 218         }
 219
 220         ahash_request_set_crypt(ahreq, plain, pctx->odata, cryptlen);
 221         err = crypto_ahash_finup(ahreq);
 222 out:
 223         return err;
 224 }
 225
 226 static void crypto_ccm_encrypt_done(struct crypto_async_request *areq, int err)
 227 {
 228         struct aead_request *req = areq->data;
 229         struct crypto_aead *aead = crypto_aead_reqtfm(req);
 230         struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
 231         u8 *odata = pctx->odata;
 232
 233         if (!err)
 234                 scatterwalk_map_and_copy(odata, req->dst,
 235                                          req->assoclen + req->cryptlen,
 236                                          crypto_aead_authsize(aead), 1);
 237         aead_request_complete(req, err);
 238 }
 239
 240 static inline int crypto_ccm_check_iv(const u8 *iv)
 241 {
 242         /* 2 <= L <= 8, so 1 <= L' <= 7. */
 243         if (1 > iv[0] || iv[0] > 7)
 244                 return -EINVAL;
 245
 246         return 0;
 247 }
 248
 249 static int crypto_ccm_init_crypt(struct aead_request *req, u8 *tag)
 250 {
 251         struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
 252         struct scatterlist *sg;
 253         u8 *iv = req->iv;
 254         int err;
 255
 256         err = crypto_ccm_check_iv(iv);
 257         if (err)
 258                 return err;
 259
 260         pctx->flags = aead_request_flags(req);
 261
 262          /* Note: rfc 3610 and NIST 800-38C require counter of
 263          * zero to encrypt auth tag.
 264          */
 265         memset(iv + 15 - iv[0], 0, iv[0] + 1);
 266
 267         sg_init_table(pctx->src, 3);
 268         sg_set_buf(pctx->src, tag, 16);
 269         sg = scatterwalk_ffwd(pctx->src + 1, req->src, req->assoclen);
 270         if (sg != pctx->src + 1)
 271                 sg_chain(pctx->src, 2, sg);
 272
 273         if (req->src != req->dst) {
 274                 sg_init_table(pctx->dst, 3);
 275                 sg_set_buf(pctx->dst, tag, 16);
 276                 sg = scatterwalk_ffwd(pctx->dst + 1, req->dst, req->assoclen);
 277                 if (sg != pctx->dst + 1)
 278                         sg_chain(pctx->dst, 2, sg);
 279         }
 280
 281         return 0;
 282 }
 283
 284 static int crypto_ccm_encrypt(struct aead_request *req)
 285 {
 286         struct crypto_aead *aead = crypto_aead_reqtfm(req);
 287         struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
 288         struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
 289         struct skcipher_request *skreq = &pctx->skreq;
 290         struct scatterlist *dst;
 291         unsigned int cryptlen = req->cryptlen;
 292         u8 *odata = pctx->odata;
 293         u8 *iv = req->iv;
 294         int err;
 295
 296         err = crypto_ccm_init_crypt(req, odata);
 297         if (err)
 298                 return err;
 299
 300         err = crypto_ccm_auth(req, sg_next(pctx->src), cryptlen);
 301         if (err)
 302                 return err;
 303
 304         dst = pctx->src;
 305         if (req->src != req->dst)
 306                 dst = pctx->dst;
 307
 308         skcipher_request_set_tfm(skreq, ctx->ctr);
 309         skcipher_request_set_callback(skreq, pctx->flags,
 310                                       crypto_ccm_encrypt_done, req);
 311         skcipher_request_set_crypt(skreq, pctx->src, dst, cryptlen + 16, iv);
 312         err = crypto_skcipher_encrypt(skreq);
 313         if (err)
 314                 return err;
 315
 316         /* copy authtag to end of dst */
 317         scatterwalk_map_and_copy(odata, sg_next(dst), cryptlen,
 318                                  crypto_aead_authsize(aead), 1);
 319         return err;
 320 }
 321
 322 static void crypto_ccm_decrypt_done(struct crypto_async_request *areq,
 323                                    int err)
 324 {
 325         struct aead_request *req = areq->data;
 326         struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
 327         struct crypto_aead *aead = crypto_aead_reqtfm(req);
 328         unsigned int authsize = crypto_aead_authsize(aead);
 329         unsigned int cryptlen = req->cryptlen - authsize;
 330         struct scatterlist *dst;
 331
 332         pctx->flags = 0;
 333
 334         dst = sg_next(req->src == req->dst ? pctx->src : pctx->dst);
 335
 336         if (!err) {
 337                 err = crypto_ccm_auth(req, dst, cryptlen);
 338                 if (!err && crypto_memneq(pctx->auth_tag, pctx->odata, authsize))
 339                         err = -EBADMSG;
 340         }
 341         aead_request_complete(req, err);
 342 }
 343
 344 static int crypto_ccm_decrypt(struct aead_request *req)
 345 {
 346         struct crypto_aead *aead = crypto_aead_reqtfm(req);
 347         struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
 348         struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
 349         struct skcipher_request *skreq = &pctx->skreq;
 350         struct scatterlist *dst;
 351         unsigned int authsize = crypto_aead_authsize(aead);
 352         unsigned int cryptlen = req->cryptlen;
 353         u8 *authtag = pctx->auth_tag;
 354         u8 *odata = pctx->odata;
 355         u8 *iv = pctx->idata;
 356         int err;
 357
 358         cryptlen -= authsize;
 359
 360         err = crypto_ccm_init_crypt(req, authtag);
 361         if (err)
 362                 return err;
 363
 364         scatterwalk_map_and_copy(authtag, sg_next(pctx->src), cryptlen,
 365                                  authsize, 0);
 366
 367         dst = pctx->src;
 368         if (req->src != req->dst)
 369                 dst = pctx->dst;
 370
 371         memcpy(iv, req->iv, 16);
 372
 373         skcipher_request_set_tfm(skreq, ctx->ctr);
 374         skcipher_request_set_callback(skreq, pctx->flags,
 375                                       crypto_ccm_decrypt_done, req);
 376         skcipher_request_set_crypt(skreq, pctx->src, dst, cryptlen + 16, iv);
 377         err = crypto_skcipher_decrypt(skreq);
 378         if (err)
 379                 return err;
 380
 381         err = crypto_ccm_auth(req, sg_next(dst), cryptlen);
 382         if (err)
 383                 return err;
 384
 385         /* verify */
 386         if (crypto_memneq(authtag, odata, authsize))
 387                 return -EBADMSG;
 388
 389         return err;
 390 }
 391
 392 static int crypto_ccm_init_tfm(struct crypto_aead *tfm)
 393 {
 394         struct aead_instance *inst = aead_alg_instance(tfm);
 395         struct ccm_instance_ctx *ictx = aead_instance_ctx(inst);
 396         struct crypto_ccm_ctx *ctx = crypto_aead_ctx(tfm);
 397         struct crypto_ahash *mac;
 398         struct crypto_skcipher *ctr;
 399         unsigned long align;
 400         int err;
 401
 402         mac = crypto_spawn_ahash(&ictx->mac);
 403         if (IS_ERR(mac))
 404                 return PTR_ERR(mac);
 405
 406         ctr = crypto_spawn_skcipher(&ictx->ctr);
 407         err = PTR_ERR(ctr);
 408         if (IS_ERR(ctr))
 409                 goto err_free_mac;
 410
 411         ctx->mac = mac;
 412         ctx->ctr = ctr;
 413
 414         align = crypto_aead_alignmask(tfm);
 415         align &= ~(crypto_tfm_ctx_alignment() - 1);
 416         crypto_aead_set_reqsize(
 417                 tfm,
 418                 align + sizeof(struct crypto_ccm_req_priv_ctx) +
 419                 max(crypto_ahash_reqsize(mac), crypto_skcipher_reqsize(ctr)));
 420
 421         return 0;
 422
 423 err_free_mac:
 424         crypto_free_ahash(mac);
 425         return err;
 426 }
 427
 428 static void crypto_ccm_exit_tfm(struct crypto_aead *tfm)
 429 {
 430         struct crypto_ccm_ctx *ctx = crypto_aead_ctx(tfm);
 431
 432         crypto_free_ahash(ctx->mac);
 433         crypto_free_skcipher(ctx->ctr);
 434 }
 435
 436 static void crypto_ccm_free(struct aead_instance *inst)
 437 {
 438         struct ccm_instance_ctx *ctx = aead_instance_ctx(inst);
 439
 440         crypto_drop_ahash(&ctx->mac);
 441         crypto_drop_skcipher(&ctx->ctr);
 442         kfree(inst);
 443 }
 444
 445 static int crypto_ccm_create_common(struct crypto_template *tmpl,
 446                                     struct rtattr **tb,
 447                                     const char *ctr_name,
 448                                     const char *mac_name)
 449 {
 450         u32 mask;
 451         struct aead_instance *inst;
 452         struct ccm_instance_ctx *ictx;
 453         struct skcipher_alg *ctr;
 454         struct hash_alg_common *mac;
 455         int err;
 456
 457         err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_AEAD, &mask);
 458         if (err)
 459                 return err;
 460
 461         inst = kzalloc(sizeof(*inst) + sizeof(*ictx), GFP_KERNEL);
 462         if (!inst)
 463                 return -ENOMEM;
 464         ictx = aead_instance_ctx(inst);
 465
 466         err = crypto_grab_ahash(&ictx->mac, aead_crypto_instance(inst),
 467                                 mac_name, 0, mask | CRYPTO_ALG_ASYNC);
 468         if (err)
 469                 goto err_free_inst;
 470         mac = crypto_spawn_ahash_alg(&ictx->mac);
 471
 472         err = -EINVAL;
 473         if (strncmp(mac->base.cra_name, "cbcmac(", 7) != 0 ||
 474             mac->digestsize != 16)
 475                 goto err_free_inst;
 476
 477         err = crypto_grab_skcipher(&ictx->ctr, aead_crypto_instance(inst),
 478                                    ctr_name, 0, mask);
 479         if (err)
 480                 goto err_free_inst;
 481         ctr = crypto_spawn_skcipher_alg(&ictx->ctr);
 482
 483         /* The skcipher algorithm must be CTR mode, using 16-byte blocks. */
 484         err = -EINVAL;
 485         if (strncmp(ctr->base.cra_name, "ctr(", 4) != 0 ||
 486             crypto_skcipher_alg_ivsize(ctr) != 16 ||
 487             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 = crypto_skcipher_alg_chunksize(ctr);
 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         u8 *dg = (u8 *)ctx + crypto_shash_descsize(pdesc->tfm) - bs;
 790
 791         ctx->len = 0;
 792         memset(dg, 0, bs);
 793
 794         return 0;
 795 }
 796
 797 static int crypto_cbcmac_digest_update(struct shash_desc *pdesc, const u8 *p,
 798                                        unsigned int len)
 799 {
 800         struct crypto_shash *parent = pdesc->tfm;
 801         struct cbcmac_tfm_ctx *tctx = crypto_shash_ctx(parent);
 802         struct cbcmac_desc_ctx *ctx = shash_desc_ctx(pdesc);
 803         struct crypto_cipher *tfm = tctx->child;
 804         int bs = crypto_shash_digestsize(parent);
 805         u8 *dg = (u8 *)ctx + crypto_shash_descsize(parent) - bs;
 806
 807         while (len > 0) {
 808                 unsigned int l = min(len, bs - ctx->len);
 809
 810                 crypto_xor(dg + ctx->len, p, l);
 811                 ctx->len +=l;
 812                 len -= l;
 813                 p += l;
 814
 815                 if (ctx->len == bs) {
 816                         crypto_cipher_encrypt_one(tfm, dg, dg);
 817                         ctx->len = 0;
 818                 }
 819         }
 820
 821         return 0;
 822 }
 823
 824 static int crypto_cbcmac_digest_final(struct shash_desc *pdesc, u8 *out)
 825 {
 826         struct crypto_shash *parent = pdesc->tfm;
 827         struct cbcmac_tfm_ctx *tctx = crypto_shash_ctx(parent);
 828         struct cbcmac_desc_ctx *ctx = shash_desc_ctx(pdesc);
 829         struct crypto_cipher *tfm = tctx->child;
 830         int bs = crypto_shash_digestsize(parent);
 831         u8 *dg = (u8 *)ctx + crypto_shash_descsize(parent) - bs;
 832
 833         if (ctx->len)
 834                 crypto_cipher_encrypt_one(tfm, dg, dg);
 835
 836         memcpy(out, dg, bs);
 837         return 0;
 838 }
 839
 840 static int cbcmac_init_tfm(struct crypto_tfm *tfm)
 841 {
 842         struct crypto_cipher *cipher;
 843         struct crypto_instance *inst = (void *)tfm->__crt_alg;
 844         struct crypto_cipher_spawn *spawn = crypto_instance_ctx(inst);
 845         struct cbcmac_tfm_ctx *ctx = crypto_tfm_ctx(tfm);
 846
 847         cipher = crypto_spawn_cipher(spawn);
 848         if (IS_ERR(cipher))
 849                 return PTR_ERR(cipher);
 850
 851         ctx->child = cipher;
 852
 853         return 0;
 854 };
 855
 856 static void cbcmac_exit_tfm(struct crypto_tfm *tfm)
 857 {
 858         struct cbcmac_tfm_ctx *ctx = crypto_tfm_ctx(tfm);
 859         crypto_free_cipher(ctx->child);
 860 }
 861
 862 static int cbcmac_create(struct crypto_template *tmpl, struct rtattr **tb)
 863 {
 864         struct shash_instance *inst;
 865         struct crypto_cipher_spawn *spawn;
 866         struct crypto_alg *alg;
 867         u32 mask;
 868         int err;
 869
 870         err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SHASH, &mask);
 871         if (err)
 872                 return err;
 873
 874         inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
 875         if (!inst)
 876                 return -ENOMEM;
 877         spawn = shash_instance_ctx(inst);
 878
 879         err = crypto_grab_cipher(spawn, shash_crypto_instance(inst),
 880                                  crypto_attr_alg_name(tb[1]), 0, mask);
 881         if (err)
 882                 goto err_free_inst;
 883         alg = crypto_spawn_cipher_alg(spawn);
 884
 885         err = crypto_inst_setname(shash_crypto_instance(inst), tmpl->name, alg);
 886         if (err)
 887                 goto err_free_inst;
 888
 889         inst->alg.base.cra_priority = alg->cra_priority;
 890         inst->alg.base.cra_blocksize = 1;
 891
 892         inst->alg.digestsize = alg->cra_blocksize;
 893         inst->alg.descsize = ALIGN(sizeof(struct cbcmac_desc_ctx),
 894                                    alg->cra_alignmask + 1) +
 895                              alg->cra_blocksize;
 896
 897         inst->alg.base.cra_ctxsize = sizeof(struct cbcmac_tfm_ctx);
 898         inst->alg.base.cra_init = cbcmac_init_tfm;
 899         inst->alg.base.cra_exit = cbcmac_exit_tfm;
 900
 901         inst->alg.init = crypto_cbcmac_digest_init;
 902         inst->alg.update = crypto_cbcmac_digest_update;
 903         inst->alg.final = crypto_cbcmac_digest_final;
 904         inst->alg.setkey = crypto_cbcmac_digest_setkey;
 905
 906         inst->free = shash_free_singlespawn_instance;
 907
 908         err = shash_register_instance(tmpl, inst);
 909         if (err) {
 910 err_free_inst:
 911                 shash_free_singlespawn_instance(inst);
 912         }
 913         return err;
 914 }
 915
 916 static struct crypto_template crypto_ccm_tmpls[] = {
 917         {
 918                 .name = "cbcmac",
 919                 .create = cbcmac_create,
 920                 .module = THIS_MODULE,
 921         }, {
 922                 .name = "ccm_base",
 923                 .create = crypto_ccm_base_create,
 924                 .module = THIS_MODULE,
 925         }, {
 926                 .name = "ccm",
 927                 .create = crypto_ccm_create,
 928                 .module = THIS_MODULE,
 929         }, {
 930                 .name = "rfc4309",
 931                 .create = crypto_rfc4309_create,
 932                 .module = THIS_MODULE,
 933         },
 934 };
 935
 936 static int __init crypto_ccm_module_init(void)
 937 {
 938         return crypto_register_templates(crypto_ccm_tmpls,
 939                                          ARRAY_SIZE(crypto_ccm_tmpls));
 940 }
 941
 942 static void __exit crypto_ccm_module_exit(void)
 943 {
 944         crypto_unregister_templates(crypto_ccm_tmpls,
 945                                     ARRAY_SIZE(crypto_ccm_tmpls));
 946 }
 947
 948 subsys_initcall(crypto_ccm_module_init);
 949 module_exit(crypto_ccm_module_exit);
 950
 951 MODULE_LICENSE("GPL");
 952 MODULE_DESCRIPTION("Counter with CBC MAC");
 953 MODULE_ALIAS_CRYPTO("ccm_base");
 954 MODULE_ALIAS_CRYPTO("rfc4309");
 955 MODULE_ALIAS_CRYPTO("ccm");
 956 MODULE_ALIAS_CRYPTO("cbcmac");