Skip to content
This repository

HTTPS clone URL

Subversion checkout URL

You can clone with HTTPS or Subversion.

Download ZIP
branch: master
Fetching contributors…

Cannot retrieve contributors at this time

file 891 lines (724 sloc) 22.059 kb
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891
/*
* CCM: Counter with CBC-MAC
*
* (C) Copyright IBM Corp. 2007 - Joy Latten <latten@us.ibm.com>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the Free
* Software Foundation; either version 2 of the License, or (at your option)
* any later version.
*
*/

#include <crypto/internal/aead.h>
#include <crypto/internal/skcipher.h>
#include <crypto/scatterwalk.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>

#include "internal.h"

struct ccm_instance_ctx {
struct crypto_skcipher_spawn ctr;
struct crypto_spawn cipher;
};

struct crypto_ccm_ctx {
struct crypto_cipher *cipher;
struct crypto_ablkcipher *ctr;
};

struct crypto_rfc4309_ctx {
struct crypto_aead *child;
u8 nonce[3];
};

struct crypto_ccm_req_priv_ctx {
u8 odata[16];
u8 idata[16];
u8 auth_tag[16];
u32 ilen;
u32 flags;
struct scatterlist src[2];
struct scatterlist dst[2];
struct ablkcipher_request abreq;
};

static inline struct crypto_ccm_req_priv_ctx *crypto_ccm_reqctx(
struct aead_request *req)
{
unsigned long align = crypto_aead_alignmask(crypto_aead_reqtfm(req));

return (void *)PTR_ALIGN((u8 *)aead_request_ctx(req), align + 1);
}

static int set_msg_len(u8 *block, unsigned int msglen, int csize)
{
__be32 data;

memset(block, 0, csize);
block += csize;

if (csize >= 4)
csize = 4;
else if (msglen > (1 << (8 * csize)))
return -EOVERFLOW;

data = cpu_to_be32(msglen);
memcpy(block - csize, (u8 *)&data + 4 - csize, csize);

return 0;
}

static int crypto_ccm_setkey(struct crypto_aead *aead, const u8 *key,
unsigned int keylen)
{
struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
struct crypto_ablkcipher *ctr = ctx->ctr;
struct crypto_cipher *tfm = ctx->cipher;
int err = 0;

crypto_ablkcipher_clear_flags(ctr, CRYPTO_TFM_REQ_MASK);
crypto_ablkcipher_set_flags(ctr, crypto_aead_get_flags(aead) &
CRYPTO_TFM_REQ_MASK);
err = crypto_ablkcipher_setkey(ctr, key, keylen);
crypto_aead_set_flags(aead, crypto_ablkcipher_get_flags(ctr) &
CRYPTO_TFM_RES_MASK);
if (err)
goto out;

crypto_cipher_clear_flags(tfm, CRYPTO_TFM_REQ_MASK);
crypto_cipher_set_flags(tfm, crypto_aead_get_flags(aead) &
CRYPTO_TFM_REQ_MASK);
err = crypto_cipher_setkey(tfm, key, keylen);
crypto_aead_set_flags(aead, crypto_cipher_get_flags(tfm) &
CRYPTO_TFM_RES_MASK);

out:
return err;
}

static int crypto_ccm_setauthsize(struct crypto_aead *tfm,
unsigned int authsize)
{
switch (authsize) {
case 4:
case 6:
case 8:
case 10:
case 12:
case 14:
case 16:
break;
default:
return -EINVAL;
}

return 0;
}

static int format_input(u8 *info, struct aead_request *req,
unsigned int cryptlen)
{
struct crypto_aead *aead = crypto_aead_reqtfm(req);
unsigned int lp = req->iv[0];
unsigned int l = lp + 1;
unsigned int m;

m = crypto_aead_authsize(aead);

memcpy(info, req->iv, 16);

/* format control info per RFC 3610 and
* NIST Special Publication 800-38C
*/
*info |= (8 * ((m - 2) / 2));
if (req->assoclen)
*info |= 64;

return set_msg_len(info + 16 - l, cryptlen, l);
}

static int format_adata(u8 *adata, unsigned int a)
{
int len = 0;

/* add control info for associated data
* RFC 3610 and NIST Special Publication 800-38C
*/
if (a < 65280) {
*(__be16 *)adata = cpu_to_be16(a);
len = 2;
} else {
*(__be16 *)adata = cpu_to_be16(0xfffe);
*(__be32 *)&adata[2] = cpu_to_be32(a);
len = 6;
}

return len;
}

static void compute_mac(struct crypto_cipher *tfm, u8 *data, int n,
struct crypto_ccm_req_priv_ctx *pctx)
{
unsigned int bs = 16;
u8 *odata = pctx->odata;
u8 *idata = pctx->idata;
int datalen, getlen;

datalen = n;

/* first time in here, block may be partially filled. */
getlen = bs - pctx->ilen;
if (datalen >= getlen) {
memcpy(idata + pctx->ilen, data, getlen);
crypto_xor(odata, idata, bs);
crypto_cipher_encrypt_one(tfm, odata, odata);
datalen -= getlen;
data += getlen;
pctx->ilen = 0;
}

/* now encrypt rest of data */
while (datalen >= bs) {
crypto_xor(odata, data, bs);
crypto_cipher_encrypt_one(tfm, odata, odata);

datalen -= bs;
data += bs;
}

/* check and see if there's leftover data that wasn't
* enough to fill a block.
*/
if (datalen) {
memcpy(idata + pctx->ilen, data, datalen);
pctx->ilen += datalen;
}
}

static void get_data_to_compute(struct crypto_cipher *tfm,
struct crypto_ccm_req_priv_ctx *pctx,
struct scatterlist *sg, unsigned int len)
{
struct scatter_walk walk;
u8 *data_src;
int n;

scatterwalk_start(&walk, sg);

while (len) {
n = scatterwalk_clamp(&walk, len);
if (!n) {
scatterwalk_start(&walk, sg_next(walk.sg));
n = scatterwalk_clamp(&walk, len);
}
data_src = scatterwalk_map(&walk, 0);

compute_mac(tfm, data_src, n, pctx);
len -= n;

scatterwalk_unmap(data_src, 0);
scatterwalk_advance(&walk, n);
scatterwalk_done(&walk, 0, len);
if (len)
crypto_yield(pctx->flags);
}

/* any leftover needs padding and then encrypted */
if (pctx->ilen) {
int padlen;
u8 *odata = pctx->odata;
u8 *idata = pctx->idata;

padlen = 16 - pctx->ilen;
memset(idata + pctx->ilen, 0, padlen);
crypto_xor(odata, idata, 16);
crypto_cipher_encrypt_one(tfm, odata, odata);
pctx->ilen = 0;
}
}

static int crypto_ccm_auth(struct aead_request *req, struct scatterlist *plain,
unsigned int cryptlen)
{
struct crypto_aead *aead = crypto_aead_reqtfm(req);
struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
struct crypto_cipher *cipher = ctx->cipher;
unsigned int assoclen = req->assoclen;
u8 *odata = pctx->odata;
u8 *idata = pctx->idata;
int err;

/* format control data for input */
err = format_input(odata, req, cryptlen);
if (err)
goto out;

/* encrypt first block to use as start in computing mac */
crypto_cipher_encrypt_one(cipher, odata, odata);

/* format associated data and compute into mac */
if (assoclen) {
pctx->ilen = format_adata(idata, assoclen);
get_data_to_compute(cipher, pctx, req->assoc, req->assoclen);
} else {
pctx->ilen = 0;
}

/* compute plaintext into mac */
get_data_to_compute(cipher, pctx, plain, cryptlen);

out:
return err;
}

static void crypto_ccm_encrypt_done(struct crypto_async_request *areq, int err)
{
struct aead_request *req = areq->data;
struct crypto_aead *aead = crypto_aead_reqtfm(req);
struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
u8 *odata = pctx->odata;

if (!err)
scatterwalk_map_and_copy(odata, req->dst, req->cryptlen,
crypto_aead_authsize(aead), 1);
aead_request_complete(req, err);
}

static inline int crypto_ccm_check_iv(const u8 *iv)
{
/* 2 <= L <= 8, so 1 <= L' <= 7. */
if (1 > iv[0] || iv[0] > 7)
return -EINVAL;

return 0;
}

static int crypto_ccm_encrypt(struct aead_request *req)
{
struct crypto_aead *aead = crypto_aead_reqtfm(req);
struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
struct ablkcipher_request *abreq = &pctx->abreq;
struct scatterlist *dst;
unsigned int cryptlen = req->cryptlen;
u8 *odata = pctx->odata;
u8 *iv = req->iv;
int err;

err = crypto_ccm_check_iv(iv);
if (err)
return err;

pctx->flags = aead_request_flags(req);

err = crypto_ccm_auth(req, req->src, cryptlen);
if (err)
return err;

/* Note: rfc 3610 and NIST 800-38C require counter of
* zero to encrypt auth tag.
*/
memset(iv + 15 - iv[0], 0, iv[0] + 1);

sg_init_table(pctx->src, 2);
sg_set_buf(pctx->src, odata, 16);
scatterwalk_sg_chain(pctx->src, 2, req->src);

dst = pctx->src;
if (req->src != req->dst) {
sg_init_table(pctx->dst, 2);
sg_set_buf(pctx->dst, odata, 16);
scatterwalk_sg_chain(pctx->dst, 2, req->dst);
dst = pctx->dst;
}

ablkcipher_request_set_tfm(abreq, ctx->ctr);
ablkcipher_request_set_callback(abreq, pctx->flags,
crypto_ccm_encrypt_done, req);
ablkcipher_request_set_crypt(abreq, pctx->src, dst, cryptlen + 16, iv);
err = crypto_ablkcipher_encrypt(abreq);
if (err)
return err;

/* copy authtag to end of dst */
scatterwalk_map_and_copy(odata, req->dst, cryptlen,
crypto_aead_authsize(aead), 1);
return err;
}

static void crypto_ccm_decrypt_done(struct crypto_async_request *areq,
int err)
{
struct aead_request *req = areq->data;
struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
struct crypto_aead *aead = crypto_aead_reqtfm(req);
unsigned int authsize = crypto_aead_authsize(aead);
unsigned int cryptlen = req->cryptlen - authsize;

if (!err) {
err = crypto_ccm_auth(req, req->dst, cryptlen);
if (!err && memcmp(pctx->auth_tag, pctx->odata, authsize))
err = -EBADMSG;
}
aead_request_complete(req, err);
}

static int crypto_ccm_decrypt(struct aead_request *req)
{
struct crypto_aead *aead = crypto_aead_reqtfm(req);
struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
struct ablkcipher_request *abreq = &pctx->abreq;
struct scatterlist *dst;
unsigned int authsize = crypto_aead_authsize(aead);
unsigned int cryptlen = req->cryptlen;
u8 *authtag = pctx->auth_tag;
u8 *odata = pctx->odata;
u8 *iv = req->iv;
int err;

if (cryptlen < authsize)
return -EINVAL;
cryptlen -= authsize;

err = crypto_ccm_check_iv(iv);
if (err)
return err;

pctx->flags = aead_request_flags(req);

scatterwalk_map_and_copy(authtag, req->src, cryptlen, authsize, 0);

memset(iv + 15 - iv[0], 0, iv[0] + 1);

sg_init_table(pctx->src, 2);
sg_set_buf(pctx->src, authtag, 16);
scatterwalk_sg_chain(pctx->src, 2, req->src);

dst = pctx->src;
if (req->src != req->dst) {
sg_init_table(pctx->dst, 2);
sg_set_buf(pctx->dst, authtag, 16);
scatterwalk_sg_chain(pctx->dst, 2, req->dst);
dst = pctx->dst;
}

ablkcipher_request_set_tfm(abreq, ctx->ctr);
ablkcipher_request_set_callback(abreq, pctx->flags,
crypto_ccm_decrypt_done, req);
ablkcipher_request_set_crypt(abreq, pctx->src, dst, cryptlen + 16, iv);
err = crypto_ablkcipher_decrypt(abreq);
if (err)
return err;

err = crypto_ccm_auth(req, req->dst, cryptlen);
if (err)
return err;

/* verify */
if (memcmp(authtag, odata, authsize))
return -EBADMSG;

return err;
}

static int crypto_ccm_init_tfm(struct crypto_tfm *tfm)
{
struct crypto_instance *inst = (void *)tfm->__crt_alg;
struct ccm_instance_ctx *ictx = crypto_instance_ctx(inst);
struct crypto_ccm_ctx *ctx = crypto_tfm_ctx(tfm);
struct crypto_cipher *cipher;
struct crypto_ablkcipher *ctr;
unsigned long align;
int err;

cipher = crypto_spawn_cipher(&ictx->cipher);
if (IS_ERR(cipher))
return PTR_ERR(cipher);

ctr = crypto_spawn_skcipher(&ictx->ctr);
err = PTR_ERR(ctr);
if (IS_ERR(ctr))
goto err_free_cipher;

ctx->cipher = cipher;
ctx->ctr = ctr;

align = crypto_tfm_alg_alignmask(tfm);
align &= ~(crypto_tfm_ctx_alignment() - 1);
tfm->crt_aead.reqsize = align +
sizeof(struct crypto_ccm_req_priv_ctx) +
crypto_ablkcipher_reqsize(ctr);

return 0;

err_free_cipher:
crypto_free_cipher(cipher);
return err;
}

static void crypto_ccm_exit_tfm(struct crypto_tfm *tfm)
{
struct crypto_ccm_ctx *ctx = crypto_tfm_ctx(tfm);

crypto_free_cipher(ctx->cipher);
crypto_free_ablkcipher(ctx->ctr);
}

static struct crypto_instance *crypto_ccm_alloc_common(struct rtattr **tb,
const char *full_name,
const char *ctr_name,
const char *cipher_name)
{
struct crypto_attr_type *algt;
struct crypto_instance *inst;
struct crypto_alg *ctr;
struct crypto_alg *cipher;
struct ccm_instance_ctx *ictx;
int err;

algt = crypto_get_attr_type(tb);
err = PTR_ERR(algt);
if (IS_ERR(algt))
return ERR_PTR(err);

if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
return ERR_PTR(-EINVAL);

cipher = crypto_alg_mod_lookup(cipher_name, CRYPTO_ALG_TYPE_CIPHER,
CRYPTO_ALG_TYPE_MASK);
err = PTR_ERR(cipher);
if (IS_ERR(cipher))
return ERR_PTR(err);

err = -EINVAL;
if (cipher->cra_blocksize != 16)
goto out_put_cipher;

inst = kzalloc(sizeof(*inst) + sizeof(*ictx), GFP_KERNEL);
err = -ENOMEM;
if (!inst)
goto out_put_cipher;

ictx = crypto_instance_ctx(inst);

err = crypto_init_spawn(&ictx->cipher, cipher, inst,
CRYPTO_ALG_TYPE_MASK);
if (err)
goto err_free_inst;

crypto_set_skcipher_spawn(&ictx->ctr, inst);
err = crypto_grab_skcipher(&ictx->ctr, ctr_name, 0,
crypto_requires_sync(algt->type,
algt->mask));
if (err)
goto err_drop_cipher;

ctr = crypto_skcipher_spawn_alg(&ictx->ctr);

/* Not a stream cipher? */
err = -EINVAL;
if (ctr->cra_blocksize != 1)
goto err_drop_ctr;

/* We want the real thing! */
if (ctr->cra_ablkcipher.ivsize != 16)
goto err_drop_ctr;

err = -ENAMETOOLONG;
if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
"ccm_base(%s,%s)", ctr->cra_driver_name,
cipher->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
goto err_drop_ctr;

memcpy(inst->alg.cra_name, full_name, CRYPTO_MAX_ALG_NAME);

inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD;
inst->alg.cra_flags |= ctr->cra_flags & CRYPTO_ALG_ASYNC;
inst->alg.cra_priority = cipher->cra_priority + ctr->cra_priority;
inst->alg.cra_blocksize = 1;
inst->alg.cra_alignmask = cipher->cra_alignmask | ctr->cra_alignmask |
(__alignof__(u32) - 1);
inst->alg.cra_type = &crypto_aead_type;
inst->alg.cra_aead.ivsize = 16;
inst->alg.cra_aead.maxauthsize = 16;
inst->alg.cra_ctxsize = sizeof(struct crypto_ccm_ctx);
inst->alg.cra_init = crypto_ccm_init_tfm;
inst->alg.cra_exit = crypto_ccm_exit_tfm;
inst->alg.cra_aead.setkey = crypto_ccm_setkey;
inst->alg.cra_aead.setauthsize = crypto_ccm_setauthsize;
inst->alg.cra_aead.encrypt = crypto_ccm_encrypt;
inst->alg.cra_aead.decrypt = crypto_ccm_decrypt;

out:
crypto_mod_put(cipher);
return inst;

err_drop_ctr:
crypto_drop_skcipher(&ictx->ctr);
err_drop_cipher:
crypto_drop_spawn(&ictx->cipher);
err_free_inst:
kfree(inst);
out_put_cipher:
inst = ERR_PTR(err);
goto out;
}

static struct crypto_instance *crypto_ccm_alloc(struct rtattr **tb)
{
int err;
const char *cipher_name;
char ctr_name[CRYPTO_MAX_ALG_NAME];
char full_name[CRYPTO_MAX_ALG_NAME];

cipher_name = crypto_attr_alg_name(tb[1]);
err = PTR_ERR(cipher_name);
if (IS_ERR(cipher_name))
return ERR_PTR(err);

if (snprintf(ctr_name, CRYPTO_MAX_ALG_NAME, "ctr(%s)",
cipher_name) >= CRYPTO_MAX_ALG_NAME)
return ERR_PTR(-ENAMETOOLONG);

if (snprintf(full_name, CRYPTO_MAX_ALG_NAME, "ccm(%s)", cipher_name) >=
CRYPTO_MAX_ALG_NAME)
return ERR_PTR(-ENAMETOOLONG);

return crypto_ccm_alloc_common(tb, full_name, ctr_name, cipher_name);
}

static void crypto_ccm_free(struct crypto_instance *inst)
{
struct ccm_instance_ctx *ctx = crypto_instance_ctx(inst);

crypto_drop_spawn(&ctx->cipher);
crypto_drop_skcipher(&ctx->ctr);
kfree(inst);
}

static struct crypto_template crypto_ccm_tmpl = {
.name = "ccm",
.alloc = crypto_ccm_alloc,
.free = crypto_ccm_free,
.module = THIS_MODULE,
};

static struct crypto_instance *crypto_ccm_base_alloc(struct rtattr **tb)
{
int err;
const char *ctr_name;
const char *cipher_name;
char full_name[CRYPTO_MAX_ALG_NAME];

ctr_name = crypto_attr_alg_name(tb[1]);
err = PTR_ERR(ctr_name);
if (IS_ERR(ctr_name))
return ERR_PTR(err);

cipher_name = crypto_attr_alg_name(tb[2]);
err = PTR_ERR(cipher_name);
if (IS_ERR(cipher_name))
return ERR_PTR(err);

if (snprintf(full_name, CRYPTO_MAX_ALG_NAME, "ccm_base(%s,%s)",
ctr_name, cipher_name) >= CRYPTO_MAX_ALG_NAME)
return ERR_PTR(-ENAMETOOLONG);

return crypto_ccm_alloc_common(tb, full_name, ctr_name, cipher_name);
}

static struct crypto_template crypto_ccm_base_tmpl = {
.name = "ccm_base",
.alloc = crypto_ccm_base_alloc,
.free = crypto_ccm_free,
.module = THIS_MODULE,
};

static int crypto_rfc4309_setkey(struct crypto_aead *parent, const u8 *key,
unsigned int keylen)
{
struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(parent);
struct crypto_aead *child = ctx->child;
int err;

if (keylen < 3)
return -EINVAL;

keylen -= 3;
memcpy(ctx->nonce, key + keylen, 3);

crypto_aead_clear_flags(child, CRYPTO_TFM_REQ_MASK);
crypto_aead_set_flags(child, crypto_aead_get_flags(parent) &
CRYPTO_TFM_REQ_MASK);
err = crypto_aead_setkey(child, key, keylen);
crypto_aead_set_flags(parent, crypto_aead_get_flags(child) &
CRYPTO_TFM_RES_MASK);

return err;
}

static int crypto_rfc4309_setauthsize(struct crypto_aead *parent,
unsigned int authsize)
{
struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(parent);

switch (authsize) {
case 8:
case 12:
case 16:
break;
default:
return -EINVAL;
}

return crypto_aead_setauthsize(ctx->child, authsize);
}

static struct aead_request *crypto_rfc4309_crypt(struct aead_request *req)
{
struct aead_request *subreq = aead_request_ctx(req);
struct crypto_aead *aead = crypto_aead_reqtfm(req);
struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(aead);
struct crypto_aead *child = ctx->child;
u8 *iv = PTR_ALIGN((u8 *)(subreq + 1) + crypto_aead_reqsize(child),
crypto_aead_alignmask(child) + 1);

/* L' */
iv[0] = 3;

memcpy(iv + 1, ctx->nonce, 3);
memcpy(iv + 4, req->iv, 8);

aead_request_set_tfm(subreq, child);
aead_request_set_callback(subreq, req->base.flags, req->base.complete,
req->base.data);
aead_request_set_crypt(subreq, req->src, req->dst, req->cryptlen, iv);
aead_request_set_assoc(subreq, req->assoc, req->assoclen);

return subreq;
}

static int crypto_rfc4309_encrypt(struct aead_request *req)
{
req = crypto_rfc4309_crypt(req);

return crypto_aead_encrypt(req);
}

static int crypto_rfc4309_decrypt(struct aead_request *req)
{
req = crypto_rfc4309_crypt(req);

return crypto_aead_decrypt(req);
}

static int crypto_rfc4309_init_tfm(struct crypto_tfm *tfm)
{
struct crypto_instance *inst = (void *)tfm->__crt_alg;
struct crypto_aead_spawn *spawn = crypto_instance_ctx(inst);
struct crypto_rfc4309_ctx *ctx = crypto_tfm_ctx(tfm);
struct crypto_aead *aead;
unsigned long align;

aead = crypto_spawn_aead(spawn);
if (IS_ERR(aead))
return PTR_ERR(aead);

ctx->child = aead;

align = crypto_aead_alignmask(aead);
align &= ~(crypto_tfm_ctx_alignment() - 1);
tfm->crt_aead.reqsize = sizeof(struct aead_request) +
ALIGN(crypto_aead_reqsize(aead),
crypto_tfm_ctx_alignment()) +
align + 16;

return 0;
}

static void crypto_rfc4309_exit_tfm(struct crypto_tfm *tfm)
{
struct crypto_rfc4309_ctx *ctx = crypto_tfm_ctx(tfm);

crypto_free_aead(ctx->child);
}

static struct crypto_instance *crypto_rfc4309_alloc(struct rtattr **tb)
{
struct crypto_attr_type *algt;
struct crypto_instance *inst;
struct crypto_aead_spawn *spawn;
struct crypto_alg *alg;
const char *ccm_name;
int err;

algt = crypto_get_attr_type(tb);
err = PTR_ERR(algt);
if (IS_ERR(algt))
return ERR_PTR(err);

if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
return ERR_PTR(-EINVAL);

ccm_name = crypto_attr_alg_name(tb[1]);
err = PTR_ERR(ccm_name);
if (IS_ERR(ccm_name))
return ERR_PTR(err);

inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
if (!inst)
return ERR_PTR(-ENOMEM);

spawn = crypto_instance_ctx(inst);
crypto_set_aead_spawn(spawn, inst);
err = crypto_grab_aead(spawn, ccm_name, 0,
crypto_requires_sync(algt->type, algt->mask));
if (err)
goto out_free_inst;

alg = crypto_aead_spawn_alg(spawn);

err = -EINVAL;

/* We only support 16-byte blocks. */
if (alg->cra_aead.ivsize != 16)
goto out_drop_alg;

/* Not a stream cipher? */
if (alg->cra_blocksize != 1)
goto out_drop_alg;

err = -ENAMETOOLONG;
if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME,
"rfc4309(%s)", alg->cra_name) >= CRYPTO_MAX_ALG_NAME ||
snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
"rfc4309(%s)", alg->cra_driver_name) >=
CRYPTO_MAX_ALG_NAME)
goto out_drop_alg;

inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD;
inst->alg.cra_flags |= alg->cra_flags & CRYPTO_ALG_ASYNC;
inst->alg.cra_priority = alg->cra_priority;
inst->alg.cra_blocksize = 1;
inst->alg.cra_alignmask = alg->cra_alignmask;
inst->alg.cra_type = &crypto_nivaead_type;

inst->alg.cra_aead.ivsize = 8;
inst->alg.cra_aead.maxauthsize = 16;

inst->alg.cra_ctxsize = sizeof(struct crypto_rfc4309_ctx);

inst->alg.cra_init = crypto_rfc4309_init_tfm;
inst->alg.cra_exit = crypto_rfc4309_exit_tfm;

inst->alg.cra_aead.setkey = crypto_rfc4309_setkey;
inst->alg.cra_aead.setauthsize = crypto_rfc4309_setauthsize;
inst->alg.cra_aead.encrypt = crypto_rfc4309_encrypt;
inst->alg.cra_aead.decrypt = crypto_rfc4309_decrypt;

inst->alg.cra_aead.geniv = "seqiv";

out:
return inst;

out_drop_alg:
crypto_drop_aead(spawn);
out_free_inst:
kfree(inst);
inst = ERR_PTR(err);
goto out;
}

static void crypto_rfc4309_free(struct crypto_instance *inst)
{
crypto_drop_spawn(crypto_instance_ctx(inst));
kfree(inst);
}

static struct crypto_template crypto_rfc4309_tmpl = {
.name = "rfc4309",
.alloc = crypto_rfc4309_alloc,
.free = crypto_rfc4309_free,
.module = THIS_MODULE,
};

static int __init crypto_ccm_module_init(void)
{
int err;

err = crypto_register_template(&crypto_ccm_base_tmpl);
if (err)
goto out;

err = crypto_register_template(&crypto_ccm_tmpl);
if (err)
goto out_undo_base;

err = crypto_register_template(&crypto_rfc4309_tmpl);
if (err)
goto out_undo_ccm;

out:
return err;

out_undo_ccm:
crypto_unregister_template(&crypto_ccm_tmpl);
out_undo_base:
crypto_unregister_template(&crypto_ccm_base_tmpl);
goto out;
}

static void __exit crypto_ccm_module_exit(void)
{
crypto_unregister_template(&crypto_rfc4309_tmpl);
crypto_unregister_template(&crypto_ccm_tmpl);
crypto_unregister_template(&crypto_ccm_base_tmpl);
}

module_init(crypto_ccm_module_init);
module_exit(crypto_ccm_module_exit);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Counter with CBC MAC");
MODULE_ALIAS("ccm_base");
MODULE_ALIAS("rfc4309");
Something went wrong with that request. Please try again.