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/skcipher.h>
  15 #include <crypto/scatterwalk.h>
  16 #include <linux/err.h>
  17 #include <linux/init.h>
  18 #include <linux/kernel.h>
  19 #include <linux/module.h>
  20 #include <linux/slab.h>
  21
  22 #include "internal.h"
  23
  24 struct ccm_instance_ctx {
  25         struct crypto_skcipher_spawn ctr;
  26         struct crypto_spawn cipher;
  27 };
  28
  29 struct crypto_ccm_ctx {
  30         struct crypto_cipher *cipher;
  31         struct crypto_ablkcipher *ctr;
  32 };
  33
  34 struct crypto_rfc4309_ctx {
  35         struct crypto_aead *child;
  36         u8 nonce[3];
  37 };
  38
  39 struct crypto_ccm_req_priv_ctx {
  40         u8 odata[16];
  41         u8 idata[16];
  42         u8 auth_tag[16];
  43         u32 ilen;
  44         u32 flags;
  45         struct scatterlist src[2];
  46         struct scatterlist dst[2];
  47         struct ablkcipher_request abreq;
  48 };
  49
  50 static inline struct crypto_ccm_req_priv_ctx *crypto_ccm_reqctx(
  51         struct aead_request *req)
  52 {
  53         unsigned long align = crypto_aead_alignmask(crypto_aead_reqtfm(req));
  54
  55         return (void *)PTR_ALIGN((u8 *)aead_request_ctx(req), align + 1);
  56 }
  57
  58 static int set_msg_len(u8 *block, unsigned int msglen, int csize)
  59 {
  60         __be32 data;
  61
  62         memset(block, 0, csize);
  63         block += csize;
  64
  65         if (csize >= 4)
  66                 csize = 4;
  67         else if (msglen > (1 << (8 * csize)))
  68                 return -EOVERFLOW;
  69
  70         data = cpu_to_be32(msglen);
  71         memcpy(block - csize, (u8 *)&data + 4 - csize, csize);
  72
  73         return 0;
  74 }
  75
  76 static int crypto_ccm_setkey(struct crypto_aead *aead, const u8 *key,
  77                              unsigned int keylen)
  78 {
  79         struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
  80         struct crypto_ablkcipher *ctr = ctx->ctr;
  81         struct crypto_cipher *tfm = ctx->cipher;
  82         int err = 0;
  83
  84         crypto_ablkcipher_clear_flags(ctr, CRYPTO_TFM_REQ_MASK);
  85         crypto_ablkcipher_set_flags(ctr, crypto_aead_get_flags(aead) &
  86                                     CRYPTO_TFM_REQ_MASK);
  87         err = crypto_ablkcipher_setkey(ctr, key, keylen);
  88         crypto_aead_set_flags(aead, crypto_ablkcipher_get_flags(ctr) &
  89                               CRYPTO_TFM_RES_MASK);
  90         if (err)
  91                 goto out;
  92
  93         crypto_cipher_clear_flags(tfm, CRYPTO_TFM_REQ_MASK);
  94         crypto_cipher_set_flags(tfm, crypto_aead_get_flags(aead) &
  95                                     CRYPTO_TFM_REQ_MASK);
  96         err = crypto_cipher_setkey(tfm, key, keylen);
  97         crypto_aead_set_flags(aead, crypto_cipher_get_flags(tfm) &
  98                               CRYPTO_TFM_RES_MASK);
  99
 100 out:
 101         return err;
 102 }
 103
 104 static int crypto_ccm_setauthsize(struct crypto_aead *tfm,
 105                                   unsigned int authsize)
 106 {
 107         switch (authsize) {
 108         case 4:
 109         case 6:
 110         case 8:
 111         case 10:
 112         case 12:
 113         case 14:
 114         case 16:
 115                 break;
 116         default:
 117                 return -EINVAL;
 118         }
 119
 120         return 0;
 121 }
 122
 123 static int format_input(u8 *info, struct aead_request *req,
 124                         unsigned int cryptlen)
 125 {
 126         struct crypto_aead *aead = crypto_aead_reqtfm(req);
 127         unsigned int lp = req->iv[0];
 128         unsigned int l = lp + 1;
 129         unsigned int m;
 130
 131         m = crypto_aead_authsize(aead);
 132
 133         memcpy(info, req->iv, 16);
 134
 135         /* format control info per RFC 3610 and
 136          * NIST Special Publication 800-38C
 137          */
 138         *info |= (8 * ((m - 2) / 2));
 139         if (req->assoclen)
 140                 *info |= 64;
 141
 142         return set_msg_len(info + 16 - l, cryptlen, l);
 143 }
 144
 145 static int format_adata(u8 *adata, unsigned int a)
 146 {
 147         int len = 0;
 148
 149         /* add control info for associated data
 150          * RFC 3610 and NIST Special Publication 800-38C
 151          */
 152         if (a < 65280) {
 153                 *(__be16 *)adata = cpu_to_be16(a);
 154                 len = 2;
 155         } else  {
 156                 *(__be16 *)adata = cpu_to_be16(0xfffe);
 157                 *(__be32 *)&adata[2] = cpu_to_be32(a);
 158                 len = 6;
 159         }
 160
 161         return len;
 162 }
 163
 164 static void compute_mac(struct crypto_cipher *tfm, u8 *data, int n,
 165                        struct crypto_ccm_req_priv_ctx *pctx)
 166 {
 167         unsigned int bs = 16;
 168         u8 *odata = pctx->odata;
 169         u8 *idata = pctx->idata;
 170         int datalen, getlen;
 171
 172         datalen = n;
 173
 174         /* first time in here, block may be partially filled. */
 175         getlen = bs - pctx->ilen;
 176         if (datalen >= getlen) {
 177                 memcpy(idata + pctx->ilen, data, getlen);
 178                 crypto_xor(odata, idata, bs);
 179                 crypto_cipher_encrypt_one(tfm, odata, odata);
 180                 datalen -= getlen;
 181                 data += getlen;
 182                 pctx->ilen = 0;
 183         }
 184
 185         /* now encrypt rest of data */
 186         while (datalen >= bs) {
 187                 crypto_xor(odata, data, bs);
 188                 crypto_cipher_encrypt_one(tfm, odata, odata);
 189
 190                 datalen -= bs;
 191                 data += bs;
 192         }
 193
 194         /* check and see if there's leftover data that wasn't
 195          * enough to fill a block.
 196          */
 197         if (datalen) {
 198                 memcpy(idata + pctx->ilen, data, datalen);
 199                 pctx->ilen += datalen;
 200         }
 201 }
 202
 203 static void get_data_to_compute(struct crypto_cipher *tfm,
 204                                struct crypto_ccm_req_priv_ctx *pctx,
 205                                struct scatterlist *sg, unsigned int len)
 206 {
 207         struct scatter_walk walk;
 208         u8 *data_src;
 209         int n;
 210
 211         scatterwalk_start(&walk, sg);
 212
 213         while (len) {
 214                 n = scatterwalk_clamp(&walk, len);
 215                 if (!n) {
 216                         scatterwalk_start(&walk, sg_next(walk.sg));
 217                         n = scatterwalk_clamp(&walk, len);
 218                 }
 219                 data_src = scatterwalk_map(&walk);
 220
 221                 compute_mac(tfm, data_src, n, pctx);
 222                 len -= n;
 223
 224                 scatterwalk_unmap(data_src);
 225                 scatterwalk_advance(&walk, n);
 226                 scatterwalk_done(&walk, 0, len);
 227                 if (len)
 228                         crypto_yield(pctx->flags);
 229         }
 230
 231         /* any leftover needs padding and then encrypted */
 232         if (pctx->ilen) {
 233                 int padlen;
 234                 u8 *odata = pctx->odata;
 235                 u8 *idata = pctx->idata;
 236
 237                 padlen = 16 - pctx->ilen;
 238                 memset(idata + pctx->ilen, 0, padlen);
 239                 crypto_xor(odata, idata, 16);
 240                 crypto_cipher_encrypt_one(tfm, odata, odata);
 241                 pctx->ilen = 0;
 242         }
 243 }
 244
 245 static int crypto_ccm_auth(struct aead_request *req, struct scatterlist *plain,
 246                            unsigned int cryptlen)
 247 {
 248         struct crypto_aead *aead = crypto_aead_reqtfm(req);
 249         struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
 250         struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
 251         struct crypto_cipher *cipher = ctx->cipher;
 252         unsigned int assoclen = req->assoclen;
 253         u8 *odata = pctx->odata;
 254         u8 *idata = pctx->idata;
 255         int err;
 256
 257         /* format control data for input */
 258         err = format_input(odata, req, cryptlen);
 259         if (err)
 260                 goto out;
 261
 262         /* encrypt first block to use as start in computing mac  */
 263         crypto_cipher_encrypt_one(cipher, odata, odata);
 264
 265         /* format associated data and compute into mac */
 266         if (assoclen) {
 267                 pctx->ilen = format_adata(idata, assoclen);
 268                 get_data_to_compute(cipher, pctx, req->assoc, req->assoclen);
 269         } else {
 270                 pctx->ilen = 0;
 271         }
 272
 273         /* compute plaintext into mac */
 274         if (cryptlen)
 275                 get_data_to_compute(cipher, pctx, plain, cryptlen);
 276
 277 out:
 278         return err;
 279 }
 280
 281 static void crypto_ccm_encrypt_done(struct crypto_async_request *areq, int err)
 282 {
 283         struct aead_request *req = areq->data;
 284         struct crypto_aead *aead = crypto_aead_reqtfm(req);
 285         struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
 286         u8 *odata = pctx->odata;
 287
 288         if (!err)
 289                 scatterwalk_map_and_copy(odata, req->dst, req->cryptlen,
 290                                          crypto_aead_authsize(aead), 1);
 291         aead_request_complete(req, err);
 292 }
 293
 294 static inline int crypto_ccm_check_iv(const u8 *iv)
 295 {
 296         /* 2 <= L <= 8, so 1 <= L' <= 7. */
 297         if (1 > iv[0] || iv[0] > 7)
 298                 return -EINVAL;
 299
 300         return 0;
 301 }
 302
 303 static int crypto_ccm_encrypt(struct aead_request *req)
 304 {
 305         struct crypto_aead *aead = crypto_aead_reqtfm(req);
 306         struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
 307         struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
 308         struct ablkcipher_request *abreq = &pctx->abreq;
 309         struct scatterlist *dst;
 310         unsigned int cryptlen = req->cryptlen;
 311         u8 *odata = pctx->odata;
 312         u8 *iv = req->iv;
 313         int err;
 314
 315         err = crypto_ccm_check_iv(iv);
 316         if (err)
 317                 return err;
 318
 319         pctx->flags = aead_request_flags(req);
 320
 321         err = crypto_ccm_auth(req, req->src, cryptlen);
 322         if (err)
 323                 return err;
 324
 325          /* Note: rfc 3610 and NIST 800-38C require counter of
 326          * zero to encrypt auth tag.
 327          */
 328         memset(iv + 15 - iv[0], 0, iv[0] + 1);
 329
 330         sg_init_table(pctx->src, 2);
 331         sg_set_buf(pctx->src, odata, 16);
 332         scatterwalk_sg_chain(pctx->src, 2, req->src);
 333
 334         dst = pctx->src;
 335         if (req->src != req->dst) {
 336                 sg_init_table(pctx->dst, 2);
 337                 sg_set_buf(pctx->dst, odata, 16);
 338                 scatterwalk_sg_chain(pctx->dst, 2, req->dst);
 339                 dst = pctx->dst;
 340         }
 341
 342         ablkcipher_request_set_tfm(abreq, ctx->ctr);
 343         ablkcipher_request_set_callback(abreq, pctx->flags,
 344                                         crypto_ccm_encrypt_done, req);
 345         ablkcipher_request_set_crypt(abreq, pctx->src, dst, cryptlen + 16, iv);
 346         err = crypto_ablkcipher_encrypt(abreq);
 347         if (err)
 348                 return err;
 349
 350         /* copy authtag to end of dst */
 351         scatterwalk_map_and_copy(odata, req->dst, cryptlen,
 352                                  crypto_aead_authsize(aead), 1);
 353         return err;
 354 }
 355
 356 static void crypto_ccm_decrypt_done(struct crypto_async_request *areq,
 357                                    int err)
 358 {
 359         struct aead_request *req = areq->data;
 360         struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
 361         struct crypto_aead *aead = crypto_aead_reqtfm(req);
 362         unsigned int authsize = crypto_aead_authsize(aead);
 363         unsigned int cryptlen = req->cryptlen - authsize;
 364
 365         if (!err) {
 366                 err = crypto_ccm_auth(req, req->dst, cryptlen);
 367                 if (!err && memcmp(pctx->auth_tag, pctx->odata, authsize))
 368                         err = -EBADMSG;
 369         }
 370         aead_request_complete(req, err);
 371 }
 372
 373 static int crypto_ccm_decrypt(struct aead_request *req)
 374 {
 375         struct crypto_aead *aead = crypto_aead_reqtfm(req);
 376         struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
 377         struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
 378         struct ablkcipher_request *abreq = &pctx->abreq;
 379         struct scatterlist *dst;
 380         unsigned int authsize = crypto_aead_authsize(aead);
 381         unsigned int cryptlen = req->cryptlen;
 382         u8 *authtag = pctx->auth_tag;
 383         u8 *odata = pctx->odata;
 384         u8 *iv = req->iv;
 385         int err;
 386
 387         if (cryptlen < authsize)
 388                 return -EINVAL;
 389         cryptlen -= authsize;
 390
 391         err = crypto_ccm_check_iv(iv);
 392         if (err)
 393                 return err;
 394
 395         pctx->flags = aead_request_flags(req);
 396
 397         scatterwalk_map_and_copy(authtag, req->src, cryptlen, authsize, 0);
 398
 399         memset(iv + 15 - iv[0], 0, iv[0] + 1);
 400
 401         sg_init_table(pctx->src, 2);
 402         sg_set_buf(pctx->src, authtag, 16);
 403         scatterwalk_sg_chain(pctx->src, 2, req->src);
 404
 405         dst = pctx->src;
 406         if (req->src != req->dst) {
 407                 sg_init_table(pctx->dst, 2);
 408                 sg_set_buf(pctx->dst, authtag, 16);
 409                 scatterwalk_sg_chain(pctx->dst, 2, req->dst);
 410                 dst = pctx->dst;
 411         }
 412
 413         ablkcipher_request_set_tfm(abreq, ctx->ctr);
 414         ablkcipher_request_set_callback(abreq, pctx->flags,
 415                                         crypto_ccm_decrypt_done, req);
 416         ablkcipher_request_set_crypt(abreq, pctx->src, dst, cryptlen + 16, iv);
 417         err = crypto_ablkcipher_decrypt(abreq);
 418         if (err)
 419                 return err;
 420
 421         err = crypto_ccm_auth(req, req->dst, cryptlen);
 422         if (err)
 423                 return err;
 424
 425         /* verify */
 426         if (memcmp(authtag, odata, authsize))
 427                 return -EBADMSG;
 428
 429         return err;
 430 }
 431
 432 static int crypto_ccm_init_tfm(struct crypto_tfm *tfm)
 433 {
 434         struct crypto_instance *inst = (void *)tfm->__crt_alg;
 435         struct ccm_instance_ctx *ictx = crypto_instance_ctx(inst);
 436         struct crypto_ccm_ctx *ctx = crypto_tfm_ctx(tfm);
 437         struct crypto_cipher *cipher;
 438         struct crypto_ablkcipher *ctr;
 439         unsigned long align;
 440         int err;
 441
 442         cipher = crypto_spawn_cipher(&ictx->cipher);
 443         if (IS_ERR(cipher))
 444                 return PTR_ERR(cipher);
 445
 446         ctr = crypto_spawn_skcipher(&ictx->ctr);
 447         err = PTR_ERR(ctr);
 448         if (IS_ERR(ctr))
 449                 goto err_free_cipher;
 450
 451         ctx->cipher = cipher;
 452         ctx->ctr = ctr;
 453
 454         align = crypto_tfm_alg_alignmask(tfm);
 455         align &= ~(crypto_tfm_ctx_alignment() - 1);
 456         tfm->crt_aead.reqsize = align +
 457                                 sizeof(struct crypto_ccm_req_priv_ctx) +
 458                                 crypto_ablkcipher_reqsize(ctr);
 459
 460         return 0;
 461
 462 err_free_cipher:
 463         crypto_free_cipher(cipher);
 464         return err;
 465 }
 466
 467 static void crypto_ccm_exit_tfm(struct crypto_tfm *tfm)
 468 {
 469         struct crypto_ccm_ctx *ctx = crypto_tfm_ctx(tfm);
 470
 471         crypto_free_cipher(ctx->cipher);
 472         crypto_free_ablkcipher(ctx->ctr);
 473 }
 474
 475 static struct crypto_instance *crypto_ccm_alloc_common(struct rtattr **tb,
 476                                                        const char *full_name,
 477                                                        const char *ctr_name,
 478                                                        const char *cipher_name)
 479 {
 480         struct crypto_attr_type *algt;
 481         struct crypto_instance *inst;
 482         struct crypto_alg *ctr;
 483         struct crypto_alg *cipher;
 484         struct ccm_instance_ctx *ictx;
 485         int err;
 486
 487         algt = crypto_get_attr_type(tb);
 488         if (IS_ERR(algt))
 489                 return ERR_CAST(algt);
 490
 491         if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
 492                 return ERR_PTR(-EINVAL);
 493
 494         cipher = crypto_alg_mod_lookup(cipher_name,  CRYPTO_ALG_TYPE_CIPHER,
 495                                        CRYPTO_ALG_TYPE_MASK);
 496         if (IS_ERR(cipher))
 497                 return ERR_CAST(cipher);
 498
 499         err = -EINVAL;
 500         if (cipher->cra_blocksize != 16)
 501                 goto out_put_cipher;
 502
 503         inst = kzalloc(sizeof(*inst) + sizeof(*ictx), GFP_KERNEL);
 504         err = -ENOMEM;
 505         if (!inst)
 506                 goto out_put_cipher;
 507
 508         ictx = crypto_instance_ctx(inst);
 509
 510         err = crypto_init_spawn(&ictx->cipher, cipher, inst,
 511                                 CRYPTO_ALG_TYPE_MASK);
 512         if (err)
 513                 goto err_free_inst;
 514
 515         crypto_set_skcipher_spawn(&ictx->ctr, inst);
 516         err = crypto_grab_skcipher(&ictx->ctr, ctr_name, 0,
 517                                    crypto_requires_sync(algt->type,
 518                                                         algt->mask));
 519         if (err)
 520                 goto err_drop_cipher;
 521
 522         ctr = crypto_skcipher_spawn_alg(&ictx->ctr);
 523
 524         /* Not a stream cipher? */
 525         err = -EINVAL;
 526         if (ctr->cra_blocksize != 1)
 527                 goto err_drop_ctr;
 528
 529         /* We want the real thing! */
 530         if (ctr->cra_ablkcipher.ivsize != 16)
 531                 goto err_drop_ctr;
 532
 533         err = -ENAMETOOLONG;
 534         if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
 535                      "ccm_base(%s,%s)", ctr->cra_driver_name,
 536                      cipher->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
 537                 goto err_drop_ctr;
 538
 539         memcpy(inst->alg.cra_name, full_name, CRYPTO_MAX_ALG_NAME);
 540
 541         inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD;
 542         inst->alg.cra_flags |= ctr->cra_flags & CRYPTO_ALG_ASYNC;
 543         inst->alg.cra_priority = cipher->cra_priority + ctr->cra_priority;
 544         inst->alg.cra_blocksize = 1;
 545         inst->alg.cra_alignmask = cipher->cra_alignmask | ctr->cra_alignmask |
 546                                   (__alignof__(u32) - 1);
 547         inst->alg.cra_type = &crypto_aead_type;
 548         inst->alg.cra_aead.ivsize = 16;
 549         inst->alg.cra_aead.maxauthsize = 16;
 550         inst->alg.cra_ctxsize = sizeof(struct crypto_ccm_ctx);
 551         inst->alg.cra_init = crypto_ccm_init_tfm;
 552         inst->alg.cra_exit = crypto_ccm_exit_tfm;
 553         inst->alg.cra_aead.setkey = crypto_ccm_setkey;
 554         inst->alg.cra_aead.setauthsize = crypto_ccm_setauthsize;
 555         inst->alg.cra_aead.encrypt = crypto_ccm_encrypt;
 556         inst->alg.cra_aead.decrypt = crypto_ccm_decrypt;
 557
 558 out:
 559         crypto_mod_put(cipher);
 560         return inst;
 561
 562 err_drop_ctr:
 563         crypto_drop_skcipher(&ictx->ctr);
 564 err_drop_cipher:
 565         crypto_drop_spawn(&ictx->cipher);
 566 err_free_inst:
 567         kfree(inst);
 568 out_put_cipher:
 569         inst = ERR_PTR(err);
 570         goto out;
 571 }
 572
 573 static struct crypto_instance *crypto_ccm_alloc(struct rtattr **tb)
 574 {
 575         const char *cipher_name;
 576         char ctr_name[CRYPTO_MAX_ALG_NAME];
 577         char full_name[CRYPTO_MAX_ALG_NAME];
 578
 579         cipher_name = crypto_attr_alg_name(tb[1]);
 580         if (IS_ERR(cipher_name))
 581                 return ERR_CAST(cipher_name);
 582
 583         if (snprintf(ctr_name, CRYPTO_MAX_ALG_NAME, "ctr(%s)",
 584                      cipher_name) >= CRYPTO_MAX_ALG_NAME)
 585                 return ERR_PTR(-ENAMETOOLONG);
 586
 587         if (snprintf(full_name, CRYPTO_MAX_ALG_NAME, "ccm(%s)", cipher_name) >=
 588             CRYPTO_MAX_ALG_NAME)
 589                 return ERR_PTR(-ENAMETOOLONG);
 590
 591         return crypto_ccm_alloc_common(tb, full_name, ctr_name, cipher_name);
 592 }
 593
 594 static void crypto_ccm_free(struct crypto_instance *inst)
 595 {
 596         struct ccm_instance_ctx *ctx = crypto_instance_ctx(inst);
 597
 598         crypto_drop_spawn(&ctx->cipher);
 599         crypto_drop_skcipher(&ctx->ctr);
 600         kfree(inst);
 601 }
 602
 603 static struct crypto_template crypto_ccm_tmpl = {
 604         .name = "ccm",
 605         .alloc = crypto_ccm_alloc,
 606         .free = crypto_ccm_free,
 607         .module = THIS_MODULE,
 608 };
 609
 610 static struct crypto_instance *crypto_ccm_base_alloc(struct rtattr **tb)
 611 {
 612         const char *ctr_name;
 613         const char *cipher_name;
 614         char full_name[CRYPTO_MAX_ALG_NAME];
 615
 616         ctr_name = crypto_attr_alg_name(tb[1]);
 617         if (IS_ERR(ctr_name))
 618                 return ERR_CAST(ctr_name);
 619
 620         cipher_name = crypto_attr_alg_name(tb[2]);
 621         if (IS_ERR(cipher_name))
 622                 return ERR_CAST(cipher_name);
 623
 624         if (snprintf(full_name, CRYPTO_MAX_ALG_NAME, "ccm_base(%s,%s)",
 625                      ctr_name, cipher_name) >= CRYPTO_MAX_ALG_NAME)
 626                 return ERR_PTR(-ENAMETOOLONG);
 627
 628         return crypto_ccm_alloc_common(tb, full_name, ctr_name, cipher_name);
 629 }
 630
 631 static struct crypto_template crypto_ccm_base_tmpl = {
 632         .name = "ccm_base",
 633         .alloc = crypto_ccm_base_alloc,
 634         .free = crypto_ccm_free,
 635         .module = THIS_MODULE,
 636 };
 637
 638 static int crypto_rfc4309_setkey(struct crypto_aead *parent, const u8 *key,
 639                                  unsigned int keylen)
 640 {
 641         struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(parent);
 642         struct crypto_aead *child = ctx->child;
 643         int err;
 644
 645         if (keylen < 3)
 646                 return -EINVAL;
 647
 648         keylen -= 3;
 649         memcpy(ctx->nonce, key + keylen, 3);
 650
 651         crypto_aead_clear_flags(child, CRYPTO_TFM_REQ_MASK);
 652         crypto_aead_set_flags(child, crypto_aead_get_flags(parent) &
 653                                      CRYPTO_TFM_REQ_MASK);
 654         err = crypto_aead_setkey(child, key, keylen);
 655         crypto_aead_set_flags(parent, crypto_aead_get_flags(child) &
 656                                       CRYPTO_TFM_RES_MASK);
 657
 658         return err;
 659 }
 660
 661 static int crypto_rfc4309_setauthsize(struct crypto_aead *parent,
 662                                       unsigned int authsize)
 663 {
 664         struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(parent);
 665
 666         switch (authsize) {
 667         case 8:
 668         case 12:
 669         case 16:
 670                 break;
 671         default:
 672                 return -EINVAL;
 673         }
 674
 675         return crypto_aead_setauthsize(ctx->child, authsize);
 676 }
 677
 678 static struct aead_request *crypto_rfc4309_crypt(struct aead_request *req)
 679 {
 680         struct aead_request *subreq = aead_request_ctx(req);
 681         struct crypto_aead *aead = crypto_aead_reqtfm(req);
 682         struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(aead);
 683         struct crypto_aead *child = ctx->child;
 684         u8 *iv = PTR_ALIGN((u8 *)(subreq + 1) + crypto_aead_reqsize(child),
 685                            crypto_aead_alignmask(child) + 1);
 686
 687         /* L' */
 688         iv[0] = 3;
 689
 690         memcpy(iv + 1, ctx->nonce, 3);
 691         memcpy(iv + 4, req->iv, 8);
 692
 693         aead_request_set_tfm(subreq, child);
 694         aead_request_set_callback(subreq, req->base.flags, req->base.complete,
 695                                   req->base.data);
 696         aead_request_set_crypt(subreq, req->src, req->dst, req->cryptlen, iv);
 697         aead_request_set_assoc(subreq, req->assoc, req->assoclen);
 698
 699         return subreq;
 700 }
 701
 702 static int crypto_rfc4309_encrypt(struct aead_request *req)
 703 {
 704         req = crypto_rfc4309_crypt(req);
 705
 706         return crypto_aead_encrypt(req);
 707 }
 708
 709 static int crypto_rfc4309_decrypt(struct aead_request *req)
 710 {
 711         req = crypto_rfc4309_crypt(req);
 712
 713         return crypto_aead_decrypt(req);
 714 }
 715
 716 static int crypto_rfc4309_init_tfm(struct crypto_tfm *tfm)
 717 {
 718         struct crypto_instance *inst = (void *)tfm->__crt_alg;
 719         struct crypto_aead_spawn *spawn = crypto_instance_ctx(inst);
 720         struct crypto_rfc4309_ctx *ctx = crypto_tfm_ctx(tfm);
 721         struct crypto_aead *aead;
 722         unsigned long align;
 723
 724         aead = crypto_spawn_aead(spawn);
 725         if (IS_ERR(aead))
 726                 return PTR_ERR(aead);
 727
 728         ctx->child = aead;
 729
 730         align = crypto_aead_alignmask(aead);
 731         align &= ~(crypto_tfm_ctx_alignment() - 1);
 732         tfm->crt_aead.reqsize = sizeof(struct aead_request) +
 733                                 ALIGN(crypto_aead_reqsize(aead),
 734                                       crypto_tfm_ctx_alignment()) +
 735                                 align + 16;
 736
 737         return 0;
 738 }
 739
 740 static void crypto_rfc4309_exit_tfm(struct crypto_tfm *tfm)
 741 {
 742         struct crypto_rfc4309_ctx *ctx = crypto_tfm_ctx(tfm);
 743
 744         crypto_free_aead(ctx->child);
 745 }
 746
 747 static struct crypto_instance *crypto_rfc4309_alloc(struct rtattr **tb)
 748 {
 749         struct crypto_attr_type *algt;
 750         struct crypto_instance *inst;
 751         struct crypto_aead_spawn *spawn;
 752         struct crypto_alg *alg;
 753         const char *ccm_name;
 754         int err;
 755
 756         algt = crypto_get_attr_type(tb);
 757         if (IS_ERR(algt))
 758                 return ERR_CAST(algt);
 759
 760         if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
 761                 return ERR_PTR(-EINVAL);
 762
 763         ccm_name = crypto_attr_alg_name(tb[1]);
 764         if (IS_ERR(ccm_name))
 765                 return ERR_CAST(ccm_name);
 766
 767         inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
 768         if (!inst)
 769                 return ERR_PTR(-ENOMEM);
 770
 771         spawn = crypto_instance_ctx(inst);
 772         crypto_set_aead_spawn(spawn, inst);
 773         err = crypto_grab_aead(spawn, ccm_name, 0,
 774                                crypto_requires_sync(algt->type, algt->mask));
 775         if (err)
 776                 goto out_free_inst;
 777
 778         alg = crypto_aead_spawn_alg(spawn);
 779
 780         err = -EINVAL;
 781
 782         /* We only support 16-byte blocks. */
 783         if (alg->cra_aead.ivsize != 16)
 784                 goto out_drop_alg;
 785
 786         /* Not a stream cipher? */
 787         if (alg->cra_blocksize != 1)
 788                 goto out_drop_alg;
 789
 790         err = -ENAMETOOLONG;
 791         if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME,
 792                      "rfc4309(%s)", alg->cra_name) >= CRYPTO_MAX_ALG_NAME ||
 793             snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
 794                      "rfc4309(%s)", alg->cra_driver_name) >=
 795             CRYPTO_MAX_ALG_NAME)
 796                 goto out_drop_alg;
 797
 798         inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD;
 799         inst->alg.cra_flags |= alg->cra_flags & CRYPTO_ALG_ASYNC;
 800         inst->alg.cra_priority = alg->cra_priority;
 801         inst->alg.cra_blocksize = 1;
 802         inst->alg.cra_alignmask = alg->cra_alignmask;
 803         inst->alg.cra_type = &crypto_nivaead_type;
 804
 805         inst->alg.cra_aead.ivsize = 8;
 806         inst->alg.cra_aead.maxauthsize = 16;
 807
 808         inst->alg.cra_ctxsize = sizeof(struct crypto_rfc4309_ctx);
 809
 810         inst->alg.cra_init = crypto_rfc4309_init_tfm;
 811         inst->alg.cra_exit = crypto_rfc4309_exit_tfm;
 812
 813         inst->alg.cra_aead.setkey = crypto_rfc4309_setkey;
 814         inst->alg.cra_aead.setauthsize = crypto_rfc4309_setauthsize;
 815         inst->alg.cra_aead.encrypt = crypto_rfc4309_encrypt;
 816         inst->alg.cra_aead.decrypt = crypto_rfc4309_decrypt;
 817
 818         inst->alg.cra_aead.geniv = "seqiv";
 819
 820 out:
 821         return inst;
 822
 823 out_drop_alg:
 824         crypto_drop_aead(spawn);
 825 out_free_inst:
 826         kfree(inst);
 827         inst = ERR_PTR(err);
 828         goto out;
 829 }
 830
 831 static void crypto_rfc4309_free(struct crypto_instance *inst)
 832 {
 833         crypto_drop_spawn(crypto_instance_ctx(inst));
 834         kfree(inst);
 835 }
 836
 837 static struct crypto_template crypto_rfc4309_tmpl = {
 838         .name = "rfc4309",
 839         .alloc = crypto_rfc4309_alloc,
 840         .free = crypto_rfc4309_free,
 841         .module = THIS_MODULE,
 842 };
 843
 844 static int __init crypto_ccm_module_init(void)
 845 {
 846         int err;
 847
 848         err = crypto_register_template(&crypto_ccm_base_tmpl);
 849         if (err)
 850                 goto out;
 851
 852         err = crypto_register_template(&crypto_ccm_tmpl);
 853         if (err)
 854                 goto out_undo_base;
 855
 856         err = crypto_register_template(&crypto_rfc4309_tmpl);
 857         if (err)
 858                 goto out_undo_ccm;
 859
 860 out:
 861         return err;
 862
 863 out_undo_ccm:
 864         crypto_unregister_template(&crypto_ccm_tmpl);
 865 out_undo_base:
 866         crypto_unregister_template(&crypto_ccm_base_tmpl);
 867         goto out;
 868 }
 869
 870 static void __exit crypto_ccm_module_exit(void)
 871 {
 872         crypto_unregister_template(&crypto_rfc4309_tmpl);
 873         crypto_unregister_template(&crypto_ccm_tmpl);
 874         crypto_unregister_template(&crypto_ccm_base_tmpl);
 875 }
 876
 877 module_init(crypto_ccm_module_init);
 878 module_exit(crypto_ccm_module_exit);
 879
 880 MODULE_LICENSE("GPL");
 881 MODULE_DESCRIPTION("Counter with CBC MAC");
 882 MODULE_ALIAS("ccm_base");
 883 MODULE_ALIAS("rfc4309");