ccm.c 25.6 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11 12 13
/*
 * 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>
14
#include <crypto/internal/hash.h>
15 16 17 18 19 20 21 22 23 24 25 26
#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;
27
	struct crypto_ahash_spawn mac;
28 29 30
};

struct crypto_ccm_ctx {
31
	struct crypto_ahash *mac;
Herbert Xu's avatar
Herbert Xu committed
32
	struct crypto_skcipher *ctr;
33 34 35 36 37 38 39
};

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

40 41 42 43 44 45
struct crypto_rfc4309_req_ctx {
	struct scatterlist src[3];
	struct scatterlist dst[3];
	struct aead_request subreq;
};

46 47
struct crypto_ccm_req_priv_ctx {
	u8 odata[16];
48
	u8 idata[16];
49 50
	u8 auth_tag[16];
	u32 flags;
51 52
	struct scatterlist src[3];
	struct scatterlist dst[3];
53 54 55 56
	union {
		struct ahash_request ahreq;
		struct skcipher_request skreq;
	};
57 58
};

59 60 61 62 63 64 65 66
struct cbcmac_tfm_ctx {
	struct crypto_cipher *child;
};

struct cbcmac_desc_ctx {
	unsigned int len;
};

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
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);
Herbert Xu's avatar
Herbert Xu committed
97
	struct crypto_skcipher *ctr = ctx->ctr;
98
	struct crypto_ahash *mac = ctx->mac;
99 100
	int err = 0;

Herbert Xu's avatar
Herbert Xu committed
101 102 103 104 105
	crypto_skcipher_clear_flags(ctr, CRYPTO_TFM_REQ_MASK);
	crypto_skcipher_set_flags(ctr, crypto_aead_get_flags(aead) &
				       CRYPTO_TFM_REQ_MASK);
	err = crypto_skcipher_setkey(ctr, key, keylen);
	crypto_aead_set_flags(aead, crypto_skcipher_get_flags(ctr) &
106 107 108 109
			      CRYPTO_TFM_RES_MASK);
	if (err)
		goto out;

110 111
	crypto_ahash_clear_flags(mac, CRYPTO_TFM_REQ_MASK);
	crypto_ahash_set_flags(mac, crypto_aead_get_flags(aead) &
112
				    CRYPTO_TFM_REQ_MASK);
113 114
	err = crypto_ahash_setkey(mac, key, keylen);
	crypto_aead_set_flags(aead, crypto_ahash_get_flags(mac) &
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
			      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 int crypto_ccm_auth(struct aead_request *req, struct scatterlist *plain,
			   unsigned int cryptlen)
{
184
	struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
185 186
	struct crypto_aead *aead = crypto_aead_reqtfm(req);
	struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
187
	struct ahash_request *ahreq = &pctx->ahreq;
188
	unsigned int assoclen = req->assoclen;
189
	struct scatterlist sg[3];
190 191
	u8 *odata = pctx->odata;
	u8 *idata = pctx->idata;
192
	int ilen, err;
193 194 195 196 197 198

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

199 200
	sg_init_table(sg, 3);
	sg_set_buf(&sg[0], odata, 16);
201 202 203

	/* format associated data and compute into mac */
	if (assoclen) {
204 205 206
		ilen = format_adata(idata, assoclen);
		sg_set_buf(&sg[1], idata, ilen);
		sg_chain(sg, 3, req->src);
207
	} else {
208 209
		ilen = 0;
		sg_chain(sg, 2, req->src);
210 211
	}

212 213 214 215 216 217 218 219 220
	ahash_request_set_tfm(ahreq, ctx->mac);
	ahash_request_set_callback(ahreq, pctx->flags, NULL, NULL);
	ahash_request_set_crypt(ahreq, sg, NULL, assoclen + ilen + 16);
	err = crypto_ahash_init(ahreq);
	if (err)
		goto out;
	err = crypto_ahash_update(ahreq);
	if (err)
		goto out;
221

222 223 224 225 226 227 228 229 230 231 232 233 234 235
	/* we need to pad the MAC input to a round multiple of the block size */
	ilen = 16 - (assoclen + ilen) % 16;
	if (ilen < 16) {
		memset(idata, 0, ilen);
		sg_init_table(sg, 2);
		sg_set_buf(&sg[0], idata, ilen);
		if (plain)
			sg_chain(sg, 2, plain);
		plain = sg;
		cryptlen += ilen;
	}

	ahash_request_set_crypt(ahreq, plain, pctx->odata, cryptlen);
	err = crypto_ahash_finup(ahreq);
236 237 238 239 240 241 242 243 244 245 246 247
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)
248 249
		scatterwalk_map_and_copy(odata, req->dst,
					 req->assoclen + req->cryptlen,
250 251 252 253 254 255 256 257 258 259 260 261 262
					 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;
}

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
static int crypto_ccm_init_crypt(struct aead_request *req, u8 *tag)
{
	struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
	struct scatterlist *sg;
	u8 *iv = req->iv;
	int err;

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

	pctx->flags = aead_request_flags(req);

	 /* 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, 3);
	sg_set_buf(pctx->src, tag, 16);
	sg = scatterwalk_ffwd(pctx->src + 1, req->src, req->assoclen);
	if (sg != pctx->src + 1)
		sg_chain(pctx->src, 2, sg);

	if (req->src != req->dst) {
		sg_init_table(pctx->dst, 3);
		sg_set_buf(pctx->dst, tag, 16);
		sg = scatterwalk_ffwd(pctx->dst + 1, req->dst, req->assoclen);
		if (sg != pctx->dst + 1)
			sg_chain(pctx->dst, 2, sg);
	}

	return 0;
}

298 299 300 301 302
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);
Herbert Xu's avatar
Herbert Xu committed
303
	struct skcipher_request *skreq = &pctx->skreq;
304 305 306 307 308 309
	struct scatterlist *dst;
	unsigned int cryptlen = req->cryptlen;
	u8 *odata = pctx->odata;
	u8 *iv = req->iv;
	int err;

310
	err = crypto_ccm_init_crypt(req, odata);
311 312 313
	if (err)
		return err;

314
	err = crypto_ccm_auth(req, sg_next(pctx->src), cryptlen);
315 316 317 318
	if (err)
		return err;

	dst = pctx->src;
319
	if (req->src != req->dst)
320 321
		dst = pctx->dst;

Herbert Xu's avatar
Herbert Xu committed
322 323 324 325 326
	skcipher_request_set_tfm(skreq, ctx->ctr);
	skcipher_request_set_callback(skreq, pctx->flags,
				      crypto_ccm_encrypt_done, req);
	skcipher_request_set_crypt(skreq, pctx->src, dst, cryptlen + 16, iv);
	err = crypto_skcipher_encrypt(skreq);
327 328 329 330
	if (err)
		return err;

	/* copy authtag to end of dst */
331
	scatterwalk_map_and_copy(odata, sg_next(dst), cryptlen,
332 333 334 335 336 337 338 339 340 341 342 343
				 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;
344 345 346 347 348
	struct scatterlist *dst;

	pctx->flags = 0;

	dst = sg_next(req->src == req->dst ? pctx->src : pctx->dst);
349 350

	if (!err) {
351
		err = crypto_ccm_auth(req, dst, cryptlen);
352
		if (!err && crypto_memneq(pctx->auth_tag, pctx->odata, authsize))
353 354 355 356 357 358 359 360 361 362
			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);
Herbert Xu's avatar
Herbert Xu committed
363
	struct skcipher_request *skreq = &pctx->skreq;
364 365 366 367 368
	struct scatterlist *dst;
	unsigned int authsize = crypto_aead_authsize(aead);
	unsigned int cryptlen = req->cryptlen;
	u8 *authtag = pctx->auth_tag;
	u8 *odata = pctx->odata;
369
	u8 *iv = pctx->idata;
370 371 372 373
	int err;

	cryptlen -= authsize;

374
	err = crypto_ccm_init_crypt(req, authtag);
375 376 377
	if (err)
		return err;

378 379
	scatterwalk_map_and_copy(authtag, sg_next(pctx->src), cryptlen,
				 authsize, 0);
380 381

	dst = pctx->src;
382
	if (req->src != req->dst)
383 384
		dst = pctx->dst;

385 386
	memcpy(iv, req->iv, 16);

Herbert Xu's avatar
Herbert Xu committed
387 388 389 390 391
	skcipher_request_set_tfm(skreq, ctx->ctr);
	skcipher_request_set_callback(skreq, pctx->flags,
				      crypto_ccm_decrypt_done, req);
	skcipher_request_set_crypt(skreq, pctx->src, dst, cryptlen + 16, iv);
	err = crypto_skcipher_decrypt(skreq);
392 393 394
	if (err)
		return err;

395
	err = crypto_ccm_auth(req, sg_next(dst), cryptlen);
396 397 398 399
	if (err)
		return err;

	/* verify */
400
	if (crypto_memneq(authtag, odata, authsize))
401 402 403 404 405
		return -EBADMSG;

	return err;
}

406
static int crypto_ccm_init_tfm(struct crypto_aead *tfm)
407
{
408 409 410
	struct aead_instance *inst = aead_alg_instance(tfm);
	struct ccm_instance_ctx *ictx = aead_instance_ctx(inst);
	struct crypto_ccm_ctx *ctx = crypto_aead_ctx(tfm);
411
	struct crypto_ahash *mac;
Herbert Xu's avatar
Herbert Xu committed
412
	struct crypto_skcipher *ctr;
413 414 415
	unsigned long align;
	int err;

416 417 418
	mac = crypto_spawn_ahash(&ictx->mac);
	if (IS_ERR(mac))
		return PTR_ERR(mac);
419

420
	ctr = crypto_spawn_skcipher(&ictx->ctr);
421 422
	err = PTR_ERR(ctr);
	if (IS_ERR(ctr))
423
		goto err_free_mac;
424

425
	ctx->mac = mac;
426 427
	ctx->ctr = ctr;

428
	align = crypto_aead_alignmask(tfm);
429
	align &= ~(crypto_tfm_ctx_alignment() - 1);
430 431
	crypto_aead_set_reqsize(
		tfm,
432
		align + sizeof(struct crypto_ccm_req_priv_ctx) +
433
		max(crypto_ahash_reqsize(mac), crypto_skcipher_reqsize(ctr)));
434 435 436

	return 0;

437 438
err_free_mac:
	crypto_free_ahash(mac);
439 440 441
	return err;
}

442
static void crypto_ccm_exit_tfm(struct crypto_aead *tfm)
443
{
444
	struct crypto_ccm_ctx *ctx = crypto_aead_ctx(tfm);
445

446
	crypto_free_ahash(ctx->mac);
Herbert Xu's avatar
Herbert Xu committed
447
	crypto_free_skcipher(ctx->ctr);
448 449
}

450 451 452 453
static void crypto_ccm_free(struct aead_instance *inst)
{
	struct ccm_instance_ctx *ctx = aead_instance_ctx(inst);

454
	crypto_drop_ahash(&ctx->mac);
455 456 457 458 459 460 461 462
	crypto_drop_skcipher(&ctx->ctr);
	kfree(inst);
}

static int crypto_ccm_create_common(struct crypto_template *tmpl,
				    struct rtattr **tb,
				    const char *full_name,
				    const char *ctr_name,
463
				    const char *mac_name)
464 465
{
	struct crypto_attr_type *algt;
466
	struct aead_instance *inst;
Herbert Xu's avatar
Herbert Xu committed
467
	struct skcipher_alg *ctr;
468 469
	struct crypto_alg *mac_alg;
	struct hash_alg_common *mac;
470 471 472 473 474
	struct ccm_instance_ctx *ictx;
	int err;

	algt = crypto_get_attr_type(tb);
	if (IS_ERR(algt))
475
		return PTR_ERR(algt);
476

477
	if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
478
		return -EINVAL;
479

480 481 482 483 484 485
	mac_alg = crypto_find_alg(mac_name, &crypto_ahash_type,
				  CRYPTO_ALG_TYPE_HASH,
				  CRYPTO_ALG_TYPE_AHASH_MASK |
				  CRYPTO_ALG_ASYNC);
	if (IS_ERR(mac_alg))
		return PTR_ERR(mac_alg);
486

487
	mac = __crypto_hash_alg_common(mac_alg);
488
	err = -EINVAL;
489 490
	if (mac->digestsize != 16)
		goto out_put_mac;
491 492 493 494

	inst = kzalloc(sizeof(*inst) + sizeof(*ictx), GFP_KERNEL);
	err = -ENOMEM;
	if (!inst)
495
		goto out_put_mac;
496

497
	ictx = aead_instance_ctx(inst);
498 499
	err = crypto_init_ahash_spawn(&ictx->mac, mac,
				      aead_crypto_instance(inst));
500 501 502
	if (err)
		goto err_free_inst;

503
	crypto_set_skcipher_spawn(&ictx->ctr, aead_crypto_instance(inst));
504 505 506
	err = crypto_grab_skcipher(&ictx->ctr, ctr_name, 0,
				   crypto_requires_sync(algt->type,
							algt->mask));
507
	if (err)
508
		goto err_drop_mac;
509

Herbert Xu's avatar
Herbert Xu committed
510
	ctr = crypto_spawn_skcipher_alg(&ictx->ctr);
511 512 513

	/* Not a stream cipher? */
	err = -EINVAL;
Herbert Xu's avatar
Herbert Xu committed
514
	if (ctr->base.cra_blocksize != 1)
515 516 517
		goto err_drop_ctr;

	/* We want the real thing! */
Herbert Xu's avatar
Herbert Xu committed
518
	if (crypto_skcipher_alg_ivsize(ctr) != 16)
519 520 521
		goto err_drop_ctr;

	err = -ENAMETOOLONG;
522
	if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
Herbert Xu's avatar
Herbert Xu committed
523
		     "ccm_base(%s,%s)", ctr->base.cra_driver_name,
524
		     mac->base.cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
525 526
		goto err_drop_ctr;

527 528
	memcpy(inst->alg.base.cra_name, full_name, CRYPTO_MAX_ALG_NAME);

Herbert Xu's avatar
Herbert Xu committed
529
	inst->alg.base.cra_flags = ctr->base.cra_flags & CRYPTO_ALG_ASYNC;
530
	inst->alg.base.cra_priority = (mac->base.cra_priority +
Herbert Xu's avatar
Herbert Xu committed
531
				       ctr->base.cra_priority) / 2;
532
	inst->alg.base.cra_blocksize = 1;
533
	inst->alg.base.cra_alignmask = mac->base.cra_alignmask |
534
				       ctr->base.cra_alignmask;
535
	inst->alg.ivsize = 16;
Herbert Xu's avatar
Herbert Xu committed
536
	inst->alg.chunksize = crypto_skcipher_alg_chunksize(ctr);
537 538 539 540 541 542 543 544 545 546 547 548 549 550
	inst->alg.maxauthsize = 16;
	inst->alg.base.cra_ctxsize = sizeof(struct crypto_ccm_ctx);
	inst->alg.init = crypto_ccm_init_tfm;
	inst->alg.exit = crypto_ccm_exit_tfm;
	inst->alg.setkey = crypto_ccm_setkey;
	inst->alg.setauthsize = crypto_ccm_setauthsize;
	inst->alg.encrypt = crypto_ccm_encrypt;
	inst->alg.decrypt = crypto_ccm_decrypt;

	inst->free = crypto_ccm_free;

	err = aead_register_instance(tmpl, inst);
	if (err)
		goto err_drop_ctr;
551

552 553
out_put_mac:
	crypto_mod_put(mac_alg);
554
	return err;
555 556 557

err_drop_ctr:
	crypto_drop_skcipher(&ictx->ctr);
558 559
err_drop_mac:
	crypto_drop_ahash(&ictx->mac);
560 561
err_free_inst:
	kfree(inst);
562
	goto out_put_mac;
563 564
}

565
static int crypto_ccm_create(struct crypto_template *tmpl, struct rtattr **tb)
566 567 568
{
	const char *cipher_name;
	char ctr_name[CRYPTO_MAX_ALG_NAME];
569
	char mac_name[CRYPTO_MAX_ALG_NAME];
570 571 572 573
	char full_name[CRYPTO_MAX_ALG_NAME];

	cipher_name = crypto_attr_alg_name(tb[1]);
	if (IS_ERR(cipher_name))
574
		return PTR_ERR(cipher_name);
575 576 577

	if (snprintf(ctr_name, CRYPTO_MAX_ALG_NAME, "ctr(%s)",
		     cipher_name) >= CRYPTO_MAX_ALG_NAME)
578
		return -ENAMETOOLONG;
579

580 581 582 583
	if (snprintf(mac_name, CRYPTO_MAX_ALG_NAME, "cbcmac(%s)",
		     cipher_name) >= CRYPTO_MAX_ALG_NAME)
		return -ENAMETOOLONG;

584 585
	if (snprintf(full_name, CRYPTO_MAX_ALG_NAME, "ccm(%s)", cipher_name) >=
	    CRYPTO_MAX_ALG_NAME)
586
		return -ENAMETOOLONG;
587

588
	return crypto_ccm_create_common(tmpl, tb, full_name, ctr_name,
589
					mac_name);
590 591 592 593
}

static struct crypto_template crypto_ccm_tmpl = {
	.name = "ccm",
594
	.create = crypto_ccm_create,
595 596 597
	.module = THIS_MODULE,
};

598 599
static int crypto_ccm_base_create(struct crypto_template *tmpl,
				  struct rtattr **tb)
600 601 602 603 604 605 606
{
	const char *ctr_name;
	const char *cipher_name;
	char full_name[CRYPTO_MAX_ALG_NAME];

	ctr_name = crypto_attr_alg_name(tb[1]);
	if (IS_ERR(ctr_name))
607
		return PTR_ERR(ctr_name);
608 609 610

	cipher_name = crypto_attr_alg_name(tb[2]);
	if (IS_ERR(cipher_name))
611
		return PTR_ERR(cipher_name);
612 613 614

	if (snprintf(full_name, CRYPTO_MAX_ALG_NAME, "ccm_base(%s,%s)",
		     ctr_name, cipher_name) >= CRYPTO_MAX_ALG_NAME)
615
		return -ENAMETOOLONG;
616

617 618
	return crypto_ccm_create_common(tmpl, tb, full_name, ctr_name,
					cipher_name);
619 620 621 622
}

static struct crypto_template crypto_ccm_base_tmpl = {
	.name = "ccm_base",
623
	.create = crypto_ccm_base_create,
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
	.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)
{
669 670
	struct crypto_rfc4309_req_ctx *rctx = aead_request_ctx(req);
	struct aead_request *subreq = &rctx->subreq;
671 672 673
	struct crypto_aead *aead = crypto_aead_reqtfm(req);
	struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(aead);
	struct crypto_aead *child = ctx->child;
674
	struct scatterlist *sg;
675 676 677 678 679 680 681 682 683
	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);

684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699
	scatterwalk_map_and_copy(iv + 16, req->src, 0, req->assoclen - 8, 0);

	sg_init_table(rctx->src, 3);
	sg_set_buf(rctx->src, iv + 16, req->assoclen - 8);
	sg = scatterwalk_ffwd(rctx->src + 1, req->src, req->assoclen);
	if (sg != rctx->src + 1)
		sg_chain(rctx->src, 2, sg);

	if (req->src != req->dst) {
		sg_init_table(rctx->dst, 3);
		sg_set_buf(rctx->dst, iv + 16, req->assoclen - 8);
		sg = scatterwalk_ffwd(rctx->dst + 1, req->dst, req->assoclen);
		if (sg != rctx->dst + 1)
			sg_chain(rctx->dst, 2, sg);
	}

700 701 702
	aead_request_set_tfm(subreq, child);
	aead_request_set_callback(subreq, req->base.flags, req->base.complete,
				  req->base.data);
703 704 705 706
	aead_request_set_crypt(subreq, rctx->src,
			       req->src == req->dst ? rctx->src : rctx->dst,
			       req->cryptlen, iv);
	aead_request_set_ad(subreq, req->assoclen - 8);
707 708 709 710 711 712

	return subreq;
}

static int crypto_rfc4309_encrypt(struct aead_request *req)
{
713 714 715
	if (req->assoclen != 16 && req->assoclen != 20)
		return -EINVAL;

716 717 718 719 720 721 722
	req = crypto_rfc4309_crypt(req);

	return crypto_aead_encrypt(req);
}

static int crypto_rfc4309_decrypt(struct aead_request *req)
{
723 724 725
	if (req->assoclen != 16 && req->assoclen != 20)
		return -EINVAL;

726 727 728 729 730
	req = crypto_rfc4309_crypt(req);

	return crypto_aead_decrypt(req);
}

731
static int crypto_rfc4309_init_tfm(struct crypto_aead *tfm)
732
{
733 734 735
	struct aead_instance *inst = aead_alg_instance(tfm);
	struct crypto_aead_spawn *spawn = aead_instance_ctx(inst);
	struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(tfm);
736 737 738 739 740 741 742 743 744 745 746
	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);
747 748 749
	crypto_aead_set_reqsize(
		tfm,
		sizeof(struct crypto_rfc4309_req_ctx) +
750
		ALIGN(crypto_aead_reqsize(aead), crypto_tfm_ctx_alignment()) +
751
		align + 32);
752 753 754 755

	return 0;
}

756
static void crypto_rfc4309_exit_tfm(struct crypto_aead *tfm)
757
{
758
	struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(tfm);
759 760 761 762

	crypto_free_aead(ctx->child);
}

763 764 765 766 767 768 769 770
static void crypto_rfc4309_free(struct aead_instance *inst)
{
	crypto_drop_aead(aead_instance_ctx(inst));
	kfree(inst);
}

static int crypto_rfc4309_create(struct crypto_template *tmpl,
				 struct rtattr **tb)
771 772
{
	struct crypto_attr_type *algt;
773
	struct aead_instance *inst;
774
	struct crypto_aead_spawn *spawn;
775
	struct aead_alg *alg;
776 777 778 779 780
	const char *ccm_name;
	int err;

	algt = crypto_get_attr_type(tb);
	if (IS_ERR(algt))
781
		return PTR_ERR(algt);
782

783
	if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
784
		return -EINVAL;
785 786 787

	ccm_name = crypto_attr_alg_name(tb[1]);
	if (IS_ERR(ccm_name))
788
		return PTR_ERR(ccm_name);
789 790 791

	inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
	if (!inst)
792
		return -ENOMEM;
793

794 795
	spawn = aead_instance_ctx(inst);
	crypto_set_aead_spawn(spawn, aead_crypto_instance(inst));
796 797 798 799 800
	err = crypto_grab_aead(spawn, ccm_name, 0,
			       crypto_requires_sync(algt->type, algt->mask));
	if (err)
		goto out_free_inst;

801
	alg = crypto_spawn_aead_alg(spawn);
802 803 804 805

	err = -EINVAL;

	/* We only support 16-byte blocks. */
806
	if (crypto_aead_alg_ivsize(alg) != 16)
807 808 809
		goto out_drop_alg;

	/* Not a stream cipher? */
810
	if (alg->base.cra_blocksize != 1)
811 812 813
		goto out_drop_alg;

	err = -ENAMETOOLONG;
814 815 816 817 818
	if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
		     "rfc4309(%s)", alg->base.cra_name) >=
	    CRYPTO_MAX_ALG_NAME ||
	    snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
		     "rfc4309(%s)", alg->base.cra_driver_name) >=
819 820 821
	    CRYPTO_MAX_ALG_NAME)
		goto out_drop_alg;

822 823 824 825
	inst->alg.base.cra_flags = alg->base.cra_flags & CRYPTO_ALG_ASYNC;
	inst->alg.base.cra_priority = alg->base.cra_priority;
	inst->alg.base.cra_blocksize = 1;
	inst->alg.base.cra_alignmask = alg->base.cra_alignmask;
826

827
	inst->alg.ivsize = 8;
Herbert Xu's avatar
Herbert Xu committed
828
	inst->alg.chunksize = crypto_aead_alg_chunksize(alg);
829
	inst->alg.maxauthsize = 16;
830

831
	inst->alg.base.cra_ctxsize = sizeof(struct crypto_rfc4309_ctx);
832

833 834
	inst->alg.init = crypto_rfc4309_init_tfm;
	inst->alg.exit = crypto_rfc4309_exit_tfm;
835

836 837 838 839
	inst->alg.setkey = crypto_rfc4309_setkey;
	inst->alg.setauthsize = crypto_rfc4309_setauthsize;
	inst->alg.encrypt = crypto_rfc4309_encrypt;
	inst->alg.decrypt = crypto_rfc4309_decrypt;
840

841 842 843 844 845
	inst->free = crypto_rfc4309_free;

	err = aead_register_instance(tmpl, inst);
	if (err)
		goto out_drop_alg;
846 847

out:
848
	return err;
849 850 851 852 853 854 855 856 857 858

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

static struct crypto_template crypto_rfc4309_tmpl = {
	.name = "rfc4309",
859
	.create = crypto_rfc4309_create,
860 861 862
	.module = THIS_MODULE,
};

863 864 865 866 867 868 869 870 871 872 873 874
static int crypto_cbcmac_digest_setkey(struct crypto_shash *parent,
				     const u8 *inkey, unsigned int keylen)
{
	struct cbcmac_tfm_ctx *ctx = crypto_shash_ctx(parent);

	return crypto_cipher_setkey(ctx->child, inkey, keylen);
}

static int crypto_cbcmac_digest_init(struct shash_desc *pdesc)
{
	struct cbcmac_desc_ctx *ctx = shash_desc_ctx(pdesc);
	int bs = crypto_shash_digestsize(pdesc->tfm);
875
	u8 *dg = (u8 *)ctx + crypto_shash_descsize(pdesc->tfm) - bs;
876 877

	ctx->len = 0;
878
	memset(dg, 0, bs);
879 880 881 882 883 884 885 886 887 888 889 890

	return 0;
}

static int crypto_cbcmac_digest_update(struct shash_desc *pdesc, const u8 *p,
				       unsigned int len)
{
	struct crypto_shash *parent = pdesc->tfm;
	struct cbcmac_tfm_ctx *tctx = crypto_shash_ctx(parent);
	struct cbcmac_desc_ctx *ctx = shash_desc_ctx(pdesc);
	struct crypto_cipher *tfm = tctx->child;
	int bs = crypto_shash_digestsize(parent);
891
	u8 *dg = (u8 *)ctx + crypto_shash_descsize(parent) - bs;
892 893 894 895

	while (len > 0) {
		unsigned int l = min(len, bs - ctx->len);

896
		crypto_xor(dg + ctx->len, p, l);
897 898 899 900 901
		ctx->len +=l;
		len -= l;
		p += l;

		if (ctx->len == bs) {
902
			crypto_cipher_encrypt_one(tfm, dg, dg);
903 904 905 906 907 908 909 910 911 912 913 914 915 916
			ctx->len = 0;
		}
	}

	return 0;
}

static int crypto_cbcmac_digest_final(struct shash_desc *pdesc, u8 *out)
{
	struct crypto_shash *parent = pdesc->tfm;
	struct cbcmac_tfm_ctx *tctx = crypto_shash_ctx(parent);
	struct cbcmac_desc_ctx *ctx = shash_desc_ctx(pdesc);
	struct crypto_cipher *tfm = tctx->child;
	int bs = crypto_shash_digestsize(parent);
917
	u8 *dg = (u8 *)ctx + crypto_shash_descsize(parent) - bs;
918 919

	if (ctx->len)
920
		crypto_cipher_encrypt_one(tfm, dg, dg);
921

922
	memcpy(out, dg, bs);
923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977
	return 0;
}

static int cbcmac_init_tfm(struct crypto_tfm *tfm)
{
	struct crypto_cipher *cipher;
	struct crypto_instance *inst = (void *)tfm->__crt_alg;
	struct crypto_spawn *spawn = crypto_instance_ctx(inst);
	struct cbcmac_tfm_ctx *ctx = crypto_tfm_ctx(tfm);

	cipher = crypto_spawn_cipher(spawn);
	if (IS_ERR(cipher))
		return PTR_ERR(cipher);

	ctx->child = cipher;

	return 0;
};

static void cbcmac_exit_tfm(struct crypto_tfm *tfm)
{
	struct cbcmac_tfm_ctx *ctx = crypto_tfm_ctx(tfm);
	crypto_free_cipher(ctx->child);
}

static int cbcmac_create(struct crypto_template *tmpl, struct rtattr **tb)
{
	struct shash_instance *inst;
	struct crypto_alg *alg;
	int err;

	err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SHASH);
	if (err)
		return err;

	alg = crypto_get_attr_alg(tb, CRYPTO_ALG_TYPE_CIPHER,
				  CRYPTO_ALG_TYPE_MASK);
	if (IS_ERR(alg))
		return PTR_ERR(alg);

	inst = shash_alloc_instance("cbcmac", alg);
	err = PTR_ERR(inst);
	if (IS_ERR(inst))
		goto out_put_alg;

	err = crypto_init_spawn(shash_instance_ctx(inst), alg,
				shash_crypto_instance(inst),
				CRYPTO_ALG_TYPE_MASK);
	if (err)
		goto out_free_inst;

	inst->alg.base.cra_priority = alg->cra_priority;
	inst->alg.base.cra_blocksize = 1;

	inst->alg.digestsize = alg->cra_blocksize;
978 979
	inst->alg.descsize = ALIGN(sizeof(struct cbcmac_desc_ctx),
				   alg->cra_alignmask + 1) +
980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008
			     alg->cra_blocksize;

	inst->alg.base.cra_ctxsize = sizeof(struct cbcmac_tfm_ctx);
	inst->alg.base.cra_init = cbcmac_init_tfm;
	inst->alg.base.cra_exit = cbcmac_exit_tfm;

	inst->alg.init = crypto_cbcmac_digest_init;
	inst->alg.update = crypto_cbcmac_digest_update;
	inst->alg.final = crypto_cbcmac_digest_final;
	inst->alg.setkey = crypto_cbcmac_digest_setkey;

	err = shash_register_instance(tmpl, inst);

out_free_inst:
	if (err)
		shash_free_instance(shash_crypto_instance(inst));

out_put_alg:
	crypto_mod_put(alg);
	return err;
}

static struct crypto_template crypto_cbcmac_tmpl = {
	.name = "cbcmac",
	.create = cbcmac_create,
	.free = shash_free_instance,
	.module = THIS_MODULE,
};

1009 1010 1011 1012
static int __init crypto_ccm_module_init(void)
{
	int err;

1013
	err = crypto_register_template(&crypto_cbcmac_tmpl);
1014 1015 1016
	if (err)
		goto out;

1017 1018 1019 1020
	err = crypto_register_template(&crypto_ccm_base_tmpl);
	if (err)
		goto out_undo_cbcmac;

1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035
	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);
1036 1037
out_undo_cbcmac:
	crypto_register_template(&crypto_cbcmac_tmpl);
1038 1039 1040 1041 1042 1043 1044 1045
	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);
1046
	crypto_unregister_template(&crypto_cbcmac_tmpl);
1047 1048 1049 1050 1051 1052 1053
}

module_init(crypto_ccm_module_init);
module_exit(crypto_ccm_module_exit);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Counter with CBC MAC");
1054 1055
MODULE_ALIAS_CRYPTO("ccm_base");
MODULE_ALIAS_CRYPTO("rfc4309");
1056
MODULE_ALIAS_CRYPTO("ccm");