crypto/ccm.c

   1 /*
   2  * CCM: Counter with CBC-MAC
   3  *
   4  * (C) Copyright IBM Corp. 2007 - Joy Latten <latten@us.ibm.com>
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License as published by the Free
   8  * Software Foundation; either version 2 of the License, or (at your option)
   9  * any later version.
  10  *
  11  */
  12
  13 #include <crypto/internal/aead.h>
  14 #include <crypto/internal/hash.h>
  15 #include <crypto/internal/skcipher.h>
  16 #include <crypto/scatterwalk.h>
  17 #include <linux/err.h>
  18 #include <linux/init.h>
  19 #include <linux/kernel.h>
  20 #include <linux/module.h>
  21 #include <linux/slab.h>
  22
  23 #include "internal.h"
  24
  25 struct ccm_instance_ctx {
  26         struct crypto_skcipher_spawn ctr;
  27         struct crypto_ahash_spawn mac;
  28 };
  29
  30 struct crypto_ccm_ctx {
  31         struct crypto_ahash *mac;
  32         struct crypto_skcipher *ctr;
  33 };
  34
  35 struct crypto_rfc4309_ctx {
  36         struct crypto_aead *child;
  37         u8 nonce[3];
  38 };
  39
  40 struct crypto_rfc4309_req_ctx {
  41         struct scatterlist src[3];
  42         struct scatterlist dst[3];
  43         struct aead_request subreq;
  44 };
  45
  46 struct crypto_ccm_req_priv_ctx {
  47         u8 odata[16];
  48         u8 idata[16];
  49         u8 auth_tag[16];
  50         u32 flags;
  51         struct scatterlist src[3];
  52         struct scatterlist dst[3];
  53         struct skcipher_request skreq;
  54 };
  55
  56 struct cbcmac_tfm_ctx {
  57         struct crypto_cipher *child;
  58 };
  59
  60 struct cbcmac_desc_ctx {
  61         unsigned int len;
  62 };
  63
  64 static inline struct crypto_ccm_req_priv_ctx *crypto_ccm_reqctx(
  65         struct aead_request *req)
  66 {
  67         unsigned long align = crypto_aead_alignmask(crypto_aead_reqtfm(req));
  68
  69         return (void *)PTR_ALIGN((u8 *)aead_request_ctx(req), align + 1);
  70 }
  71
  72 static int set_msg_len(u8 *block, unsigned int msglen, int csize)
  73 {
  74         __be32 data;
  75
  76         memset(block, 0, csize);
  77         block += csize;
  78
  79         if (csize >= 4)
  80                 csize = 4;
  81         else if (msglen > (1 << (8 * csize)))
  82                 return -EOVERFLOW;
  83
  84         data = cpu_to_be32(msglen);
  85         memcpy(block - csize, (u8 *)&data + 4 - csize, csize);
  86
  87         return 0;
  88 }
  89
  90 static int crypto_ccm_setkey(struct crypto_aead *aead, const u8 *key,
  91                              unsigned int keylen)
  92 {
  93         struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
  94         struct crypto_skcipher *ctr = ctx->ctr;
  95         struct crypto_ahash *mac = ctx->mac;
  96         int err = 0;
  97
  98         crypto_skcipher_clear_flags(ctr, CRYPTO_TFM_REQ_MASK);
  99         crypto_skcipher_set_flags(ctr, crypto_aead_get_flags(aead) &
 100                                        CRYPTO_TFM_REQ_MASK);
 101         err = crypto_skcipher_setkey(ctr, key, keylen);
 102         crypto_aead_set_flags(aead, crypto_skcipher_get_flags(ctr) &
 103                               CRYPTO_TFM_RES_MASK);
 104         if (err)
 105                 goto out;
 106
 107         crypto_ahash_clear_flags(mac, CRYPTO_TFM_REQ_MASK);
 108         crypto_ahash_set_flags(mac, crypto_aead_get_flags(aead) &
 109                                     CRYPTO_TFM_REQ_MASK);
 110         err = crypto_ahash_setkey(mac, key, keylen);
 111         crypto_aead_set_flags(aead, crypto_ahash_get_flags(mac) &
 112                               CRYPTO_TFM_RES_MASK);
 113
 114 out:
 115         return err;
 116 }
 117
 118 static int crypto_ccm_setauthsize(struct crypto_aead *tfm,
 119                                   unsigned int authsize)
 120 {
 121         switch (authsize) {
 122         case 4:
 123         case 6:
 124         case 8:
 125         case 10:
 126         case 12:
 127         case 14:
 128         case 16:
 129                 break;
 130         default:
 131                 return -EINVAL;
 132         }
 133
 134         return 0;
 135 }
 136
 137 static int format_input(u8 *info, struct aead_request *req,
 138                         unsigned int cryptlen)
 139 {
 140         struct crypto_aead *aead = crypto_aead_reqtfm(req);
 141         unsigned int lp = req->iv[0];
 142         unsigned int l = lp + 1;
 143         unsigned int m;
 144
 145         m = crypto_aead_authsize(aead);
 146
 147         memcpy(info, req->iv, 16);
 148
 149         /* format control info per RFC 3610 and
 150          * NIST Special Publication 800-38C
 151          */
 152         *info |= (8 * ((m - 2) / 2));
 153         if (req->assoclen)
 154                 *info |= 64;
 155
 156         return set_msg_len(info + 16 - l, cryptlen, l);
 157 }
 158
 159 static int format_adata(u8 *adata, unsigned int a)
 160 {
 161         int len = 0;
 162
 163         /* add control info for associated data
 164          * RFC 3610 and NIST Special Publication 800-38C
 165          */
 166         if (a < 65280) {
 167                 *(__be16 *)adata = cpu_to_be16(a);
 168                 len = 2;
 169         } else  {
 170                 *(__be16 *)adata = cpu_to_be16(0xfffe);
 171                 *(__be32 *)&adata[2] = cpu_to_be32(a);
 172                 len = 6;
 173         }
 174
 175         return len;
 176 }
 177
 178 static int crypto_ccm_auth(struct aead_request *req, struct scatterlist *plain,
 179                            unsigned int cryptlen)
 180 {
 181         struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
 182         struct crypto_aead *aead = crypto_aead_reqtfm(req);
 183         struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
 184         AHASH_REQUEST_ON_STACK(ahreq, ctx->mac);
 185         unsigned int assoclen = req->assoclen;
 186         struct scatterlist sg[3];
 187         u8 *odata = pctx->odata;
 188         u8 *idata = pctx->idata;
 189         int ilen, err;
 190
 191         /* format control data for input */
 192         err = format_input(odata, req, cryptlen);
 193         if (err)
 194                 goto out;
 195
 196         sg_init_table(sg, 3);
 197         sg_set_buf(&sg[0], odata, 16);
 198
 199         /* format associated data and compute into mac */
 200         if (assoclen) {
 201                 ilen = format_adata(idata, assoclen);
 202                 sg_set_buf(&sg[1], idata, ilen);
 203                 sg_chain(sg, 3, req->src);
 204         } else {
 205                 ilen = 0;
 206                 sg_chain(sg, 2, req->src);
 207         }
 208
 209         ahash_request_set_tfm(ahreq, ctx->mac);
 210         ahash_request_set_callback(ahreq, pctx->flags, NULL, NULL);
 211         ahash_request_set_crypt(ahreq, sg, NULL, assoclen + ilen + 16);
 212         err = crypto_ahash_init(ahreq);
 213         if (err)
 214                 goto out;
 215         err = crypto_ahash_update(ahreq);
 216         if (err)
 217                 goto out;
 218
 219         /* we need to pad the MAC input to a round multiple of the block size */
 220         ilen = 16 - (assoclen + ilen) % 16;
 221         if (ilen < 16) {
 222                 memset(idata, 0, ilen);
 223                 sg_init_table(sg, 2);
 224                 sg_set_buf(&sg[0], idata, ilen);
 225                 if (plain)
 226                         sg_chain(sg, 2, plain);
 227                 plain = sg;
 228                 cryptlen += ilen;
 229         }
 230
 231         ahash_request_set_crypt(ahreq, plain, pctx->odata, cryptlen);
 232         err = crypto_ahash_finup(ahreq);
 233 out:
 234         return err;
 235 }
 236
 237 static void crypto_ccm_encrypt_done(struct crypto_async_request *areq, int err)
 238 {
 239         struct aead_request *req = areq->data;
 240         struct crypto_aead *aead = crypto_aead_reqtfm(req);
 241         struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
 242         u8 *odata = pctx->odata;
 243
 244         if (!err)
 245                 scatterwalk_map_and_copy(odata, req->dst,
 246                                          req->assoclen + req->cryptlen,
 247                                          crypto_aead_authsize(aead), 1);
 248         aead_request_complete(req, err);
 249 }
 250
 251 static inline int crypto_ccm_check_iv(const u8 *iv)
 252 {
 253         /* 2 <= L <= 8, so 1 <= L' <= 7. */
 254         if (1 > iv[0] || iv[0] > 7)
 255                 return -EINVAL;
 256
 257         return 0;
 258 }
 259
 260 static int crypto_ccm_init_crypt(struct aead_request *req, u8 *tag)
 261 {
 262         struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
 263         struct scatterlist *sg;
 264         u8 *iv = req->iv;
 265         int err;
 266
 267         err = crypto_ccm_check_iv(iv);
 268         if (err)
 269                 return err;
 270
 271         pctx->flags = aead_request_flags(req);
 272
 273          /* Note: rfc 3610 and NIST 800-38C require counter of
 274          * zero to encrypt auth tag.
 275          */
 276         memset(iv + 15 - iv[0], 0, iv[0] + 1);
 277
 278         sg_init_table(pctx->src, 3);
 279         sg_set_buf(pctx->src, tag, 16);
 280         sg = scatterwalk_ffwd(pctx->src + 1, req->src, req->assoclen);
 281         if (sg != pctx->src + 1)
 282                 sg_chain(pctx->src, 2, sg);
 283
 284         if (req->src != req->dst) {
 285                 sg_init_table(pctx->dst, 3);
 286                 sg_set_buf(pctx->dst, tag, 16);
 287                 sg = scatterwalk_ffwd(pctx->dst + 1, req->dst, req->assoclen);
 288                 if (sg != pctx->dst + 1)
 289                         sg_chain(pctx->dst, 2, sg);
 290         }
 291
 292         return 0;
 293 }
 294
 295 static int crypto_ccm_encrypt(struct aead_request *req)
 296 {
 297         struct crypto_aead *aead = crypto_aead_reqtfm(req);
 298         struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
 299         struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
 300         struct skcipher_request *skreq = &pctx->skreq;
 301         struct scatterlist *dst;
 302         unsigned int cryptlen = req->cryptlen;
 303         u8 *odata = pctx->odata;
 304         u8 *iv = req->iv;
 305         int err;
 306
 307         err = crypto_ccm_init_crypt(req, odata);
 308         if (err)
 309                 return err;
 310
 311         err = crypto_ccm_auth(req, sg_next(pctx->src), cryptlen);
 312         if (err)
 313                 return err;
 314
 315         dst = pctx->src;
 316         if (req->src != req->dst)
 317                 dst = pctx->dst;
 318
 319         skcipher_request_set_tfm(skreq, ctx->ctr);
 320         skcipher_request_set_callback(skreq, pctx->flags,
 321                                       crypto_ccm_encrypt_done, req);
 322         skcipher_request_set_crypt(skreq, pctx->src, dst, cryptlen + 16, iv);
 323         err = crypto_skcipher_encrypt(skreq);
 324         if (err)
 325                 return err;
 326
 327         /* copy authtag to end of dst */
 328         scatterwalk_map_and_copy(odata, sg_next(dst), cryptlen,
 329                                  crypto_aead_authsize(aead), 1);
 330         return err;
 331 }
 332
 333 static void crypto_ccm_decrypt_done(struct crypto_async_request *areq,
 334                                    int err)
 335 {
 336         struct aead_request *req = areq->data;
 337         struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
 338         struct crypto_aead *aead = crypto_aead_reqtfm(req);
 339         unsigned int authsize = crypto_aead_authsize(aead);
 340         unsigned int cryptlen = req->cryptlen - authsize;
 341         struct scatterlist *dst;
 342
 343         pctx->flags = 0;
 344
 345         dst = sg_next(req->src == req->dst ? pctx->src : pctx->dst);
 346
 347         if (!err) {
 348                 err = crypto_ccm_auth(req, dst, cryptlen);
 349                 if (!err && crypto_memneq(pctx->auth_tag, pctx->odata, authsize))
 350                         err = -EBADMSG;
 351         }
 352         aead_request_complete(req, err);
 353 }
 354
 355 static int crypto_ccm_decrypt(struct aead_request *req)
 356 {
 357         struct crypto_aead *aead = crypto_aead_reqtfm(req);
 358         struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
 359         struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
 360         struct skcipher_request *skreq = &pctx->skreq;
 361         struct scatterlist *dst;
 362         unsigned int authsize = crypto_aead_authsize(aead);
 363         unsigned int cryptlen = req->cryptlen;
 364         u8 *authtag = pctx->auth_tag;
 365         u8 *odata = pctx->odata;
 366         u8 *iv = pctx->idata;
 367         int err;
 368
 369         cryptlen -= authsize;
 370
 371         err = crypto_ccm_init_crypt(req, authtag);
 372         if (err)
 373                 return err;
 374
 375         scatterwalk_map_and_copy(authtag, sg_next(pctx->src), cryptlen,
 376                                  authsize, 0);
 377
 378         dst = pctx->src;
 379         if (req->src != req->dst)
 380                 dst = pctx->dst;
 381
 382         memcpy(iv, req->iv, 16);
 383
 384         skcipher_request_set_tfm(skreq, ctx->ctr);
 385         skcipher_request_set_callback(skreq, pctx->flags,
 386                                       crypto_ccm_decrypt_done, req);
 387         skcipher_request_set_crypt(skreq, pctx->src, dst, cryptlen + 16, iv);
 388         err = crypto_skcipher_decrypt(skreq);
 389         if (err)
 390                 return err;
 391
 392         err = crypto_ccm_auth(req, sg_next(dst), cryptlen);
 393         if (err)
 394                 return err;
 395
 396         /* verify */
 397         if (crypto_memneq(authtag, odata, authsize))
 398                 return -EBADMSG;
 399
 400         return err;
 401 }
 402
 403 static int crypto_ccm_init_tfm(struct crypto_aead *tfm)
 404 {
 405         struct aead_instance *inst = aead_alg_instance(tfm);
 406         struct ccm_instance_ctx *ictx = aead_instance_ctx(inst);
 407         struct crypto_ccm_ctx *ctx = crypto_aead_ctx(tfm);
 408         struct crypto_ahash *mac;
 409         struct crypto_skcipher *ctr;
 410         unsigned long align;
 411         int err;
 412
 413         mac = crypto_spawn_ahash(&ictx->mac);
 414         if (IS_ERR(mac))
 415                 return PTR_ERR(mac);
 416
 417         ctr = crypto_spawn_skcipher(&ictx->ctr);
 418         err = PTR_ERR(ctr);
 419         if (IS_ERR(ctr))
 420                 goto err_free_mac;
 421
 422         ctx->mac = mac;
 423         ctx->ctr = ctr;
 424
 425         align = crypto_aead_alignmask(tfm);
 426         align &= ~(crypto_tfm_ctx_alignment() - 1);
 427         crypto_aead_set_reqsize(
 428                 tfm,
 429                 align + sizeof(struct crypto_ccm_req_priv_ctx) +
 430                 crypto_skcipher_reqsize(ctr));
 431
 432         return 0;
 433
 434 err_free_mac:
 435         crypto_free_ahash(mac);
 436         return err;
 437 }
 438
 439 static void crypto_ccm_exit_tfm(struct crypto_aead *tfm)
 440 {
 441         struct crypto_ccm_ctx *ctx = crypto_aead_ctx(tfm);
 442
 443         crypto_free_ahash(ctx->mac);
 444         crypto_free_skcipher(ctx->ctr);
 445 }
 446
 447 static void crypto_ccm_free(struct aead_instance *inst)
 448 {
 449         struct ccm_instance_ctx *ctx = aead_instance_ctx(inst);
 450
 451         crypto_drop_ahash(&ctx->mac);
 452         crypto_drop_skcipher(&ctx->ctr);
 453         kfree(inst);
 454 }
 455
 456 static int crypto_ccm_create_common(struct crypto_template *tmpl,
 457                                     struct rtattr **tb,
 458                                     const char *full_name,
 459                                     const char *ctr_name,
 460                                     const char *mac_name)
 461 {
 462         struct crypto_attr_type *algt;
 463         struct aead_instance *inst;
 464         struct skcipher_alg *ctr;
 465         struct crypto_alg *mac_alg;
 466         struct hash_alg_common *mac;
 467         struct ccm_instance_ctx *ictx;
 468         int err;
 469
 470         algt = crypto_get_attr_type(tb);
 471         if (IS_ERR(algt))
 472                 return PTR_ERR(algt);
 473
 474         if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
 475                 return -EINVAL;
 476
 477         mac_alg = crypto_find_alg(mac_name, &crypto_ahash_type,
 478                                   CRYPTO_ALG_TYPE_HASH,
 479                                   CRYPTO_ALG_TYPE_AHASH_MASK |
 480                                   CRYPTO_ALG_ASYNC);
 481         if (IS_ERR(mac_alg))
 482                 return PTR_ERR(mac_alg);
 483
 484         mac = __crypto_hash_alg_common(mac_alg);
 485         err = -EINVAL;
 486         if (mac->digestsize != 16)
 487                 goto out_put_mac;
 488
 489         inst = kzalloc(sizeof(*inst) + sizeof(*ictx), GFP_KERNEL);
 490         err = -ENOMEM;
 491         if (!inst)
 492                 goto out_put_mac;
 493
 494         ictx = aead_instance_ctx(inst);
 495         err = crypto_init_ahash_spawn(&ictx->mac, mac,
 496                                       aead_crypto_instance(inst));
 497         if (err)
 498                 goto err_free_inst;
 499
 500         crypto_set_skcipher_spawn(&ictx->ctr, aead_crypto_instance(inst));
 501         err = crypto_grab_skcipher(&ictx->ctr, ctr_name, 0,
 502                                    crypto_requires_sync(algt->type,
 503                                                         algt->mask));
 504         if (err)
 505                 goto err_drop_mac;
 506
 507         ctr = crypto_spawn_skcipher_alg(&ictx->ctr);
 508
 509         /* Not a stream cipher? */
 510         err = -EINVAL;
 511         if (ctr->base.cra_blocksize != 1)
 512                 goto err_drop_ctr;
 513
 514         /* We want the real thing! */
 515         if (crypto_skcipher_alg_ivsize(ctr) != 16)
 516                 goto err_drop_ctr;
 517
 518         err = -ENAMETOOLONG;
 519         if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
 520                      "ccm_base(%s,%s)", ctr->base.cra_driver_name,
 521                      mac->base.cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
 522                 goto err_drop_ctr;
 523
 524         memcpy(inst->alg.base.cra_name, full_name, CRYPTO_MAX_ALG_NAME);
 525
 526         inst->alg.base.cra_flags = ctr->base.cra_flags & CRYPTO_ALG_ASYNC;
 527         inst->alg.base.cra_priority = (mac->base.cra_priority +
 528                                        ctr->base.cra_priority) / 2;
 529         inst->alg.base.cra_blocksize = 1;
 530         inst->alg.base.cra_alignmask = mac->base.cra_alignmask |
 531                                        ctr->base.cra_alignmask;
 532         inst->alg.ivsize = 16;
 533         inst->alg.chunksize = crypto_skcipher_alg_chunksize(ctr);
 534         inst->alg.maxauthsize = 16;
 535         inst->alg.base.cra_ctxsize = sizeof(struct crypto_ccm_ctx);
 536         inst->alg.init = crypto_ccm_init_tfm;
 537         inst->alg.exit = crypto_ccm_exit_tfm;
 538         inst->alg.setkey = crypto_ccm_setkey;
 539         inst->alg.setauthsize = crypto_ccm_setauthsize;
 540         inst->alg.encrypt = crypto_ccm_encrypt;
 541         inst->alg.decrypt = crypto_ccm_decrypt;
 542
 543         inst->free = crypto_ccm_free;
 544
 545         err = aead_register_instance(tmpl, inst);
 546         if (err)
 547                 goto err_drop_ctr;
 548
 549 out_put_mac:
 550         crypto_mod_put(mac_alg);
 551         return err;
 552
 553 err_drop_ctr:
 554         crypto_drop_skcipher(&ictx->ctr);
 555 err_drop_mac:
 556         crypto_drop_ahash(&ictx->mac);
 557 err_free_inst:
 558         kfree(inst);
 559         goto out_put_mac;
 560 }
 561
 562 static int crypto_ccm_create(struct crypto_template *tmpl, struct rtattr **tb)
 563 {
 564         const char *cipher_name;
 565         char ctr_name[CRYPTO_MAX_ALG_NAME];
 566         char mac_name[CRYPTO_MAX_ALG_NAME];
 567         char full_name[CRYPTO_MAX_ALG_NAME];
 568
 569         cipher_name = crypto_attr_alg_name(tb[1]);
 570         if (IS_ERR(cipher_name))
 571                 return PTR_ERR(cipher_name);
 572
 573         if (snprintf(ctr_name, CRYPTO_MAX_ALG_NAME, "ctr(%s)",
 574                      cipher_name) >= CRYPTO_MAX_ALG_NAME)
 575                 return -ENAMETOOLONG;
 576
 577         if (snprintf(mac_name, CRYPTO_MAX_ALG_NAME, "cbcmac(%s)",
 578                      cipher_name) >= CRYPTO_MAX_ALG_NAME)
 579                 return -ENAMETOOLONG;
 580
 581         if (snprintf(full_name, CRYPTO_MAX_ALG_NAME, "ccm(%s)", cipher_name) >=
 582             CRYPTO_MAX_ALG_NAME)
 583                 return -ENAMETOOLONG;
 584
 585         return crypto_ccm_create_common(tmpl, tb, full_name, ctr_name,
 586                                         mac_name);
 587 }
 588
 589 static struct crypto_template crypto_ccm_tmpl = {
 590         .name = "ccm",
 591         .create = crypto_ccm_create,
 592         .module = THIS_MODULE,
 593 };
 594
 595 static int crypto_ccm_base_create(struct crypto_template *tmpl,
 596                                   struct rtattr **tb)
 597 {
 598         const char *ctr_name;
 599         const char *cipher_name;
 600         char full_name[CRYPTO_MAX_ALG_NAME];
 601
 602         ctr_name = crypto_attr_alg_name(tb[1]);
 603         if (IS_ERR(ctr_name))
 604                 return PTR_ERR(ctr_name);
 605
 606         cipher_name = crypto_attr_alg_name(tb[2]);
 607         if (IS_ERR(cipher_name))
 608                 return PTR_ERR(cipher_name);
 609
 610         if (snprintf(full_name, CRYPTO_MAX_ALG_NAME, "ccm_base(%s,%s)",
 611                      ctr_name, cipher_name) >= CRYPTO_MAX_ALG_NAME)
 612                 return -ENAMETOOLONG;
 613
 614         return crypto_ccm_create_common(tmpl, tb, full_name, ctr_name,
 615                                         cipher_name);
 616 }
 617
 618 static struct crypto_template crypto_ccm_base_tmpl = {
 619         .name = "ccm_base",
 620         .create = crypto_ccm_base_create,
 621         .module = THIS_MODULE,
 622 };
 623
 624 static int crypto_rfc4309_setkey(struct crypto_aead *parent, const u8 *key,
 625                                  unsigned int keylen)
 626 {
 627         struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(parent);
 628         struct crypto_aead *child = ctx->child;
 629         int err;
 630
 631         if (keylen < 3)
 632                 return -EINVAL;
 633
 634         keylen -= 3;
 635         memcpy(ctx->nonce, key + keylen, 3);
 636
 637         crypto_aead_clear_flags(child, CRYPTO_TFM_REQ_MASK);
 638         crypto_aead_set_flags(child, crypto_aead_get_flags(parent) &
 639                                      CRYPTO_TFM_REQ_MASK);
 640         err = crypto_aead_setkey(child, key, keylen);
 641         crypto_aead_set_flags(parent, crypto_aead_get_flags(child) &
 642                                       CRYPTO_TFM_RES_MASK);
 643
 644         return err;
 645 }
 646
 647 static int crypto_rfc4309_setauthsize(struct crypto_aead *parent,
 648                                       unsigned int authsize)
 649 {
 650         struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(parent);
 651
 652         switch (authsize) {
 653         case 8:
 654         case 12:
 655         case 16:
 656                 break;
 657         default:
 658                 return -EINVAL;
 659         }
 660
 661         return crypto_aead_setauthsize(ctx->child, authsize);
 662 }
 663
 664 static struct aead_request *crypto_rfc4309_crypt(struct aead_request *req)
 665 {
 666         struct crypto_rfc4309_req_ctx *rctx = aead_request_ctx(req);
 667         struct aead_request *subreq = &rctx->subreq;
 668         struct crypto_aead *aead = crypto_aead_reqtfm(req);
 669         struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(aead);
 670         struct crypto_aead *child = ctx->child;
 671         struct scatterlist *sg;
 672         u8 *iv = PTR_ALIGN((u8 *)(subreq + 1) + crypto_aead_reqsize(child),
 673                            crypto_aead_alignmask(child) + 1);
 674
 675         /* L' */
 676         iv[0] = 3;
 677
 678         memcpy(iv + 1, ctx->nonce, 3);
 679         memcpy(iv + 4, req->iv, 8);
 680
 681         scatterwalk_map_and_copy(iv + 16, req->src, 0, req->assoclen - 8, 0);
 682
 683         sg_init_table(rctx->src, 3);
 684         sg_set_buf(rctx->src, iv + 16, req->assoclen - 8);
 685         sg = scatterwalk_ffwd(rctx->src + 1, req->src, req->assoclen);
 686         if (sg != rctx->src + 1)
 687                 sg_chain(rctx->src, 2, sg);
 688
 689         if (req->src != req->dst) {
 690                 sg_init_table(rctx->dst, 3);
 691                 sg_set_buf(rctx->dst, iv + 16, req->assoclen - 8);
 692                 sg = scatterwalk_ffwd(rctx->dst + 1, req->dst, req->assoclen);
 693                 if (sg != rctx->dst + 1)
 694                         sg_chain(rctx->dst, 2, sg);
 695         }
 696
 697         aead_request_set_tfm(subreq, child);
 698         aead_request_set_callback(subreq, req->base.flags, req->base.complete,
 699                                   req->base.data);
 700         aead_request_set_crypt(subreq, rctx->src,
 701                                req->src == req->dst ? rctx->src : rctx->dst,
 702                                req->cryptlen, iv);
 703         aead_request_set_ad(subreq, req->assoclen - 8);
 704
 705         return subreq;
 706 }
 707
 708 static int crypto_rfc4309_encrypt(struct aead_request *req)
 709 {
 710         if (req->assoclen != 16 && req->assoclen != 20)
 711                 return -EINVAL;
 712
 713         req = crypto_rfc4309_crypt(req);
 714
 715         return crypto_aead_encrypt(req);
 716 }
 717
 718 static int crypto_rfc4309_decrypt(struct aead_request *req)
 719 {
 720         if (req->assoclen != 16 && req->assoclen != 20)
 721                 return -EINVAL;
 722
 723         req = crypto_rfc4309_crypt(req);
 724
 725         return crypto_aead_decrypt(req);
 726 }
 727
 728 static int crypto_rfc4309_init_tfm(struct crypto_aead *tfm)
 729 {
 730         struct aead_instance *inst = aead_alg_instance(tfm);
 731         struct crypto_aead_spawn *spawn = aead_instance_ctx(inst);
 732         struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(tfm);
 733         struct crypto_aead *aead;
 734         unsigned long align;
 735
 736         aead = crypto_spawn_aead(spawn);
 737         if (IS_ERR(aead))
 738                 return PTR_ERR(aead);
 739
 740         ctx->child = aead;
 741
 742         align = crypto_aead_alignmask(aead);
 743         align &= ~(crypto_tfm_ctx_alignment() - 1);
 744         crypto_aead_set_reqsize(
 745                 tfm,
 746                 sizeof(struct crypto_rfc4309_req_ctx) +
 747                 ALIGN(crypto_aead_reqsize(aead), crypto_tfm_ctx_alignment()) +
 748                 align + 32);
 749
 750         return 0;
 751 }
 752
 753 static void crypto_rfc4309_exit_tfm(struct crypto_aead *tfm)
 754 {
 755         struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(tfm);
 756
 757         crypto_free_aead(ctx->child);
 758 }
 759
 760 static void crypto_rfc4309_free(struct aead_instance *inst)
 761 {
 762         crypto_drop_aead(aead_instance_ctx(inst));
 763         kfree(inst);
 764 }
 765
 766 static int crypto_rfc4309_create(struct crypto_template *tmpl,
 767                                  struct rtattr **tb)
 768 {
 769         struct crypto_attr_type *algt;
 770         struct aead_instance *inst;
 771         struct crypto_aead_spawn *spawn;
 772         struct aead_alg *alg;
 773         const char *ccm_name;
 774         int err;
 775
 776         algt = crypto_get_attr_type(tb);
 777         if (IS_ERR(algt))
 778                 return PTR_ERR(algt);
 779
 780         if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
 781                 return -EINVAL;
 782
 783         ccm_name = crypto_attr_alg_name(tb[1]);
 784         if (IS_ERR(ccm_name))
 785                 return PTR_ERR(ccm_name);
 786
 787         inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
 788         if (!inst)
 789                 return -ENOMEM;
 790
 791         spawn = aead_instance_ctx(inst);
 792         crypto_set_aead_spawn(spawn, aead_crypto_instance(inst));
 793         err = crypto_grab_aead(spawn, ccm_name, 0,
 794                                crypto_requires_sync(algt->type, algt->mask));
 795         if (err)
 796                 goto out_free_inst;
 797
 798         alg = crypto_spawn_aead_alg(spawn);
 799
 800         err = -EINVAL;
 801
 802         /* We only support 16-byte blocks. */
 803         if (crypto_aead_alg_ivsize(alg) != 16)
 804                 goto out_drop_alg;
 805
 806         /* Not a stream cipher? */
 807         if (alg->base.cra_blocksize != 1)
 808                 goto out_drop_alg;
 809
 810         err = -ENAMETOOLONG;
 811         if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
 812                      "rfc4309(%s)", alg->base.cra_name) >=
 813             CRYPTO_MAX_ALG_NAME ||
 814             snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
 815                      "rfc4309(%s)", alg->base.cra_driver_name) >=
 816             CRYPTO_MAX_ALG_NAME)
 817                 goto out_drop_alg;
 818
 819         inst->alg.base.cra_flags = alg->base.cra_flags & CRYPTO_ALG_ASYNC;
 820         inst->alg.base.cra_priority = alg->base.cra_priority;
 821         inst->alg.base.cra_blocksize = 1;
 822         inst->alg.base.cra_alignmask = alg->base.cra_alignmask;
 823
 824         inst->alg.ivsize = 8;
 825         inst->alg.chunksize = crypto_aead_alg_chunksize(alg);
 826         inst->alg.maxauthsize = 16;
 827
 828         inst->alg.base.cra_ctxsize = sizeof(struct crypto_rfc4309_ctx);
 829
 830         inst->alg.init = crypto_rfc4309_init_tfm;
 831         inst->alg.exit = crypto_rfc4309_exit_tfm;
 832
 833         inst->alg.setkey = crypto_rfc4309_setkey;
 834         inst->alg.setauthsize = crypto_rfc4309_setauthsize;
 835         inst->alg.encrypt = crypto_rfc4309_encrypt;
 836         inst->alg.decrypt = crypto_rfc4309_decrypt;
 837
 838         inst->free = crypto_rfc4309_free;
 839
 840         err = aead_register_instance(tmpl, inst);
 841         if (err)
 842                 goto out_drop_alg;
 843
 844 out:
 845         return err;
 846
 847 out_drop_alg:
 848         crypto_drop_aead(spawn);
 849 out_free_inst:
 850         kfree(inst);
 851         goto out;
 852 }
 853
 854 static struct crypto_template crypto_rfc4309_tmpl = {
 855         .name = "rfc4309",
 856         .create = crypto_rfc4309_create,
 857         .module = THIS_MODULE,
 858 };
 859
 860 static int crypto_cbcmac_digest_setkey(struct crypto_shash *parent,
 861                                      const u8 *inkey, unsigned int keylen)
 862 {
 863         struct cbcmac_tfm_ctx *ctx = crypto_shash_ctx(parent);
 864
 865         return crypto_cipher_setkey(ctx->child, inkey, keylen);
 866 }
 867
 868 static int crypto_cbcmac_digest_init(struct shash_desc *pdesc)
 869 {
 870         struct cbcmac_desc_ctx *ctx = shash_desc_ctx(pdesc);
 871         int bs = crypto_shash_digestsize(pdesc->tfm);
 872         u8 *dg = (u8 *)ctx + crypto_shash_descsize(pdesc->tfm) - bs;
 873
 874         ctx->len = 0;
 875         memset(dg, 0, bs);
 876
 877         return 0;
 878 }
 879
 880 static int crypto_cbcmac_digest_update(struct shash_desc *pdesc, const u8 *p,
 881                                        unsigned int len)
 882 {
 883         struct crypto_shash *parent = pdesc->tfm;
 884         struct cbcmac_tfm_ctx *tctx = crypto_shash_ctx(parent);
 885         struct cbcmac_desc_ctx *ctx = shash_desc_ctx(pdesc);
 886         struct crypto_cipher *tfm = tctx->child;
 887         int bs = crypto_shash_digestsize(parent);
 888         u8 *dg = (u8 *)ctx + crypto_shash_descsize(parent) - bs;
 889
 890         while (len > 0) {
 891                 unsigned int l = min(len, bs - ctx->len);
 892
 893                 crypto_xor(dg + ctx->len, p, l);
 894                 ctx->len +=l;
 895                 len -= l;
 896                 p += l;
 897
 898                 if (ctx->len == bs) {
 899                         crypto_cipher_encrypt_one(tfm, dg, dg);
 900                         ctx->len = 0;
 901                 }
 902         }
 903
 904         return 0;
 905 }
 906
 907 static int crypto_cbcmac_digest_final(struct shash_desc *pdesc, u8 *out)
 908 {
 909         struct crypto_shash *parent = pdesc->tfm;
 910         struct cbcmac_tfm_ctx *tctx = crypto_shash_ctx(parent);
 911         struct cbcmac_desc_ctx *ctx = shash_desc_ctx(pdesc);
 912         struct crypto_cipher *tfm = tctx->child;
 913         int bs = crypto_shash_digestsize(parent);
 914         u8 *dg = (u8 *)ctx + crypto_shash_descsize(parent) - bs;
 915
 916         if (ctx->len)
 917                 crypto_cipher_encrypt_one(tfm, dg, dg);
 918
 919         memcpy(out, dg, bs);
 920         return 0;
 921 }
 922
 923 static int cbcmac_init_tfm(struct crypto_tfm *tfm)
 924 {
 925         struct crypto_cipher *cipher;
 926         struct crypto_instance *inst = (void *)tfm->__crt_alg;
 927         struct crypto_spawn *spawn = crypto_instance_ctx(inst);
 928         struct cbcmac_tfm_ctx *ctx = crypto_tfm_ctx(tfm);
 929
 930         cipher = crypto_spawn_cipher(spawn);
 931         if (IS_ERR(cipher))
 932                 return PTR_ERR(cipher);
 933
 934         ctx->child = cipher;
 935
 936         return 0;
 937 };
 938
 939 static void cbcmac_exit_tfm(struct crypto_tfm *tfm)
 940 {
 941         struct cbcmac_tfm_ctx *ctx = crypto_tfm_ctx(tfm);
 942         crypto_free_cipher(ctx->child);
 943 }
 944
 945 static int cbcmac_create(struct crypto_template *tmpl, struct rtattr **tb)
 946 {
 947         struct shash_instance *inst;
 948         struct crypto_alg *alg;
 949         int err;
 950
 951         err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SHASH);
 952         if (err)
 953                 return err;
 954
 955         alg = crypto_get_attr_alg(tb, CRYPTO_ALG_TYPE_CIPHER,
 956                                   CRYPTO_ALG_TYPE_MASK);
 957         if (IS_ERR(alg))
 958                 return PTR_ERR(alg);
 959
 960         inst = shash_alloc_instance("cbcmac", alg);
 961         err = PTR_ERR(inst);
 962         if (IS_ERR(inst))
 963                 goto out_put_alg;
 964
 965         err = crypto_init_spawn(shash_instance_ctx(inst), alg,
 966                                 shash_crypto_instance(inst),
 967                                 CRYPTO_ALG_TYPE_MASK);
 968         if (err)
 969                 goto out_free_inst;
 970
 971         inst->alg.base.cra_priority = alg->cra_priority;
 972         inst->alg.base.cra_blocksize = 1;
 973
 974         inst->alg.digestsize = alg->cra_blocksize;
 975         inst->alg.descsize = ALIGN(sizeof(struct cbcmac_desc_ctx),
 976                                    alg->cra_alignmask + 1) +
 977                              alg->cra_blocksize;
 978
 979         inst->alg.base.cra_ctxsize = sizeof(struct cbcmac_tfm_ctx);
 980         inst->alg.base.cra_init = cbcmac_init_tfm;
 981         inst->alg.base.cra_exit = cbcmac_exit_tfm;
 982
 983         inst->alg.init = crypto_cbcmac_digest_init;
 984         inst->alg.update = crypto_cbcmac_digest_update;
 985         inst->alg.final = crypto_cbcmac_digest_final;
 986         inst->alg.setkey = crypto_cbcmac_digest_setkey;
 987
 988         err = shash_register_instance(tmpl, inst);
 989
 990 out_free_inst:
 991         if (err)
 992                 shash_free_instance(shash_crypto_instance(inst));
 993
 994 out_put_alg:
 995         crypto_mod_put(alg);
 996         return err;
 997 }
 998
 999 static struct crypto_template crypto_cbcmac_tmpl = {
1000         .name = "cbcmac",
1001         .create = cbcmac_create,
1002         .free = shash_free_instance,
1003         .module = THIS_MODULE,
1004 };
1005
1006 static int __init crypto_ccm_module_init(void)
1007 {
1008         int err;
1009
1010         err = crypto_register_template(&crypto_cbcmac_tmpl);
1011         if (err)
1012                 goto out;
1013
1014         err = crypto_register_template(&crypto_ccm_base_tmpl);
1015         if (err)
1016                 goto out_undo_cbcmac;
1017
1018         err = crypto_register_template(&crypto_ccm_tmpl);
1019         if (err)
1020                 goto out_undo_base;
1021
1022         err = crypto_register_template(&crypto_rfc4309_tmpl);
1023         if (err)
1024                 goto out_undo_ccm;
1025
1026 out:
1027         return err;
1028
1029 out_undo_ccm:
1030         crypto_unregister_template(&crypto_ccm_tmpl);
1031 out_undo_base:
1032         crypto_unregister_template(&crypto_ccm_base_tmpl);
1033 out_undo_cbcmac:
1034         crypto_register_template(&crypto_cbcmac_tmpl);
1035         goto out;
1036 }
1037
1038 static void __exit crypto_ccm_module_exit(void)
1039 {
1040         crypto_unregister_template(&crypto_rfc4309_tmpl);
1041         crypto_unregister_template(&crypto_ccm_tmpl);
1042         crypto_unregister_template(&crypto_ccm_base_tmpl);
1043         crypto_unregister_template(&crypto_cbcmac_tmpl);
1044 }
1045
1046 module_init(crypto_ccm_module_init);
1047 module_exit(crypto_ccm_module_exit);
1048
1049 MODULE_LICENSE("GPL");
1050 MODULE_DESCRIPTION("Counter with CBC MAC");
1051 MODULE_ALIAS_CRYPTO("ccm_base");
1052 MODULE_ALIAS_CRYPTO("rfc4309");
1053 MODULE_ALIAS_CRYPTO("ccm");