gcm.c

   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * GCM: Galois/Counter Mode.
   4 *
   5 * Copyright (c) 2007 Nokia Siemens Networks - Mikko Herranen <mh1@iki.fi>
   6 */
   7
   8#include <crypto/gf128mul.h>
   9#include <crypto/internal/aead.h>
  10#include <crypto/internal/skcipher.h>
  11#include <crypto/internal/hash.h>
  12#include <crypto/scatterwalk.h>
  13#include <crypto/gcm.h>
  14#include <crypto/hash.h>
  15#include <linux/err.h>
  16#include <linux/init.h>
  17#include <linux/kernel.h>
  18#include <linux/module.h>
  19#include <linux/slab.h>
  20
  21struct gcm_instance_ctx {
  22	struct crypto_skcipher_spawn ctr;
  23	struct crypto_ahash_spawn ghash;
  24};
  25
  26struct crypto_gcm_ctx {
  27	struct crypto_skcipher *ctr;
  28	struct crypto_ahash *ghash;
  29};
  30
  31struct crypto_rfc4106_ctx {
  32	struct crypto_aead *child;
  33	u8 nonce[4];
  34};
  35
  36struct crypto_rfc4106_req_ctx {
  37	struct scatterlist src[3];
  38	struct scatterlist dst[3];
  39	struct aead_request subreq;
  40};
  41
  42struct crypto_rfc4543_instance_ctx {
  43	struct crypto_aead_spawn aead;
  44};
  45
  46struct crypto_rfc4543_ctx {
  47	struct crypto_aead *child;
  48	u8 nonce[4];
  49};
  50
  51struct crypto_rfc4543_req_ctx {
  52	struct aead_request subreq;
  53};
  54
  55struct crypto_gcm_ghash_ctx {
  56	unsigned int cryptlen;
  57	struct scatterlist *src;
  58	int (*complete)(struct aead_request *req, u32 flags);
  59};
  60
  61struct crypto_gcm_req_priv_ctx {
  62	u8 iv[16];
  63	u8 auth_tag[16];
  64	u8 iauth_tag[16];
  65	struct scatterlist src[3];
  66	struct scatterlist dst[3];
  67	struct scatterlist sg;
  68	struct crypto_gcm_ghash_ctx ghash_ctx;
  69	union {
  70		struct ahash_request ahreq;
  71		struct skcipher_request skreq;
  72	} u;
  73};
  74
  75static struct {
  76	u8 buf[16];
  77	struct scatterlist sg;
  78} *gcm_zeroes;
  79
  80static inline struct crypto_gcm_req_priv_ctx *crypto_gcm_reqctx(
  81	struct aead_request *req)
  82{
  83	unsigned long align = crypto_aead_alignmask(crypto_aead_reqtfm(req));
  84
  85	return (void *)PTR_ALIGN((u8 *)aead_request_ctx(req), align + 1);
  86}
  87
  88static int crypto_gcm_setkey(struct crypto_aead *aead, const u8 *key,
  89			     unsigned int keylen)
  90{
  91	struct crypto_gcm_ctx *ctx = crypto_aead_ctx(aead);
  92	struct crypto_ahash *ghash = ctx->ghash;
  93	struct crypto_skcipher *ctr = ctx->ctr;
  94	struct {
  95		be128 hash;
  96		u8 iv[16];
  97
  98		struct crypto_wait wait;
  99
 100		struct scatterlist sg[1];
 101		struct skcipher_request req;
 102	} *data;
 103	int err;
 104
 105	crypto_skcipher_clear_flags(ctr, CRYPTO_TFM_REQ_MASK);
 106	crypto_skcipher_set_flags(ctr, crypto_aead_get_flags(aead) &
 107				       CRYPTO_TFM_REQ_MASK);
 108	err = crypto_skcipher_setkey(ctr, key, keylen);
 109	if (err)
 110		return err;
 111
 112	data = kzalloc(sizeof(*data) + crypto_skcipher_reqsize(ctr),
 113		       GFP_KERNEL);
 114	if (!data)
 115		return -ENOMEM;
 116
 117	crypto_init_wait(&data->wait);
 118	sg_init_one(data->sg, &data->hash, sizeof(data->hash));
 119	skcipher_request_set_tfm(&data->req, ctr);
 120	skcipher_request_set_callback(&data->req, CRYPTO_TFM_REQ_MAY_SLEEP |
 121						  CRYPTO_TFM_REQ_MAY_BACKLOG,
 122				      crypto_req_done,
 123				      &data->wait);
 124	skcipher_request_set_crypt(&data->req, data->sg, data->sg,
 125				   sizeof(data->hash), data->iv);
 126
 127	err = crypto_wait_req(crypto_skcipher_encrypt(&data->req),
 128							&data->wait);
 129
 130	if (err)
 131		goto out;
 132
 133	crypto_ahash_clear_flags(ghash, CRYPTO_TFM_REQ_MASK);
 134	crypto_ahash_set_flags(ghash, crypto_aead_get_flags(aead) &
 135			       CRYPTO_TFM_REQ_MASK);
 136	err = crypto_ahash_setkey(ghash, (u8 *)&data->hash, sizeof(be128));
 137out:
 138	kfree_sensitive(data);
 139	return err;
 140}
 141
 142static int crypto_gcm_setauthsize(struct crypto_aead *tfm,
 143				  unsigned int authsize)
 144{
 145	return crypto_gcm_check_authsize(authsize);
 146}
 147
 148static void crypto_gcm_init_common(struct aead_request *req)
 149{
 150	struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
 151	__be32 counter = cpu_to_be32(1);
 152	struct scatterlist *sg;
 153
 154	memset(pctx->auth_tag, 0, sizeof(pctx->auth_tag));
 155	memcpy(pctx->iv, req->iv, GCM_AES_IV_SIZE);
 156	memcpy(pctx->iv + GCM_AES_IV_SIZE, &counter, 4);
 157
 158	sg_init_table(pctx->src, 3);
 159	sg_set_buf(pctx->src, pctx->auth_tag, sizeof(pctx->auth_tag));
 160	sg = scatterwalk_ffwd(pctx->src + 1, req->src, req->assoclen);
 161	if (sg != pctx->src + 1)
 162		sg_chain(pctx->src, 2, sg);
 163
 164	if (req->src != req->dst) {
 165		sg_init_table(pctx->dst, 3);
 166		sg_set_buf(pctx->dst, pctx->auth_tag, sizeof(pctx->auth_tag));
 167		sg = scatterwalk_ffwd(pctx->dst + 1, req->dst, req->assoclen);
 168		if (sg != pctx->dst + 1)
 169			sg_chain(pctx->dst, 2, sg);
 170	}
 171}
 172
 173static void crypto_gcm_init_crypt(struct aead_request *req,
 174				  unsigned int cryptlen)
 175{
 176	struct crypto_aead *aead = crypto_aead_reqtfm(req);
 177	struct crypto_gcm_ctx *ctx = crypto_aead_ctx(aead);
 178	struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
 179	struct skcipher_request *skreq = &pctx->u.skreq;
 180	struct scatterlist *dst;
 181
 182	dst = req->src == req->dst ? pctx->src : pctx->dst;
 183
 184	skcipher_request_set_tfm(skreq, ctx->ctr);
 185	skcipher_request_set_crypt(skreq, pctx->src, dst,
 186				     cryptlen + sizeof(pctx->auth_tag),
 187				     pctx->iv);
 188}
 189
 190static inline unsigned int gcm_remain(unsigned int len)
 191{
 192	len &= 0xfU;
 193	return len ? 16 - len : 0;
 194}
 195
 196static void gcm_hash_len_done(void *data, int err);
 197
 198static int gcm_hash_update(struct aead_request *req,
 199			   crypto_completion_t compl,
 200			   struct scatterlist *src,
 201			   unsigned int len, u32 flags)
 202{
 203	struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
 204	struct ahash_request *ahreq = &pctx->u.ahreq;
 205
 206	ahash_request_set_callback(ahreq, flags, compl, req);
 207	ahash_request_set_crypt(ahreq, src, NULL, len);
 208
 209	return crypto_ahash_update(ahreq);
 210}
 211
 212static int gcm_hash_remain(struct aead_request *req,
 213			   unsigned int remain,
 214			   crypto_completion_t compl, u32 flags)
 215{
 216	return gcm_hash_update(req, compl, &gcm_zeroes->sg, remain, flags);
 217}
 218
 219static int gcm_hash_len(struct aead_request *req, u32 flags)
 220{
 221	struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
 222	struct ahash_request *ahreq = &pctx->u.ahreq;
 223	struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx;
 224	be128 lengths;
 225
 226	lengths.a = cpu_to_be64(req->assoclen * 8);
 227	lengths.b = cpu_to_be64(gctx->cryptlen * 8);
 228	memcpy(pctx->iauth_tag, &lengths, 16);
 229	sg_init_one(&pctx->sg, pctx->iauth_tag, 16);
 230	ahash_request_set_callback(ahreq, flags, gcm_hash_len_done, req);
 231	ahash_request_set_crypt(ahreq, &pctx->sg,
 232				pctx->iauth_tag, sizeof(lengths));
 233
 234	return crypto_ahash_finup(ahreq);
 235}
 236
 237static int gcm_hash_len_continue(struct aead_request *req, u32 flags)
 238{
 239	struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
 240	struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx;
 241
 242	return gctx->complete(req, flags);
 243}
 244
 245static void gcm_hash_len_done(void *data, int err)
 246{
 247	struct aead_request *req = data;
 248
 249	if (err)
 250		goto out;
 251
 252	err = gcm_hash_len_continue(req, 0);
 253	if (err == -EINPROGRESS)
 254		return;
 255
 256out:
 257	aead_request_complete(req, err);
 258}
 259
 260static int gcm_hash_crypt_remain_continue(struct aead_request *req, u32 flags)
 261{
 262	return gcm_hash_len(req, flags) ?:
 263	       gcm_hash_len_continue(req, flags);
 264}
 265
 266static void gcm_hash_crypt_remain_done(void *data, int err)
 267{
 268	struct aead_request *req = data;
 269
 270	if (err)
 271		goto out;
 272
 273	err = gcm_hash_crypt_remain_continue(req, 0);
 274	if (err == -EINPROGRESS)
 275		return;
 276
 277out:
 278	aead_request_complete(req, err);
 279}
 280
 281static int gcm_hash_crypt_continue(struct aead_request *req, u32 flags)
 282{
 283	struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
 284	struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx;
 285	unsigned int remain;
 286
 287	remain = gcm_remain(gctx->cryptlen);
 288	if (remain)
 289		return gcm_hash_remain(req, remain,
 290				       gcm_hash_crypt_remain_done, flags) ?:
 291		       gcm_hash_crypt_remain_continue(req, flags);
 292
 293	return gcm_hash_crypt_remain_continue(req, flags);
 294}
 295
 296static void gcm_hash_crypt_done(void *data, int err)
 297{
 298	struct aead_request *req = data;
 299
 300	if (err)
 301		goto out;
 302
 303	err = gcm_hash_crypt_continue(req, 0);
 304	if (err == -EINPROGRESS)
 305		return;
 306
 307out:
 308	aead_request_complete(req, err);
 309}
 310
 311static int gcm_hash_assoc_remain_continue(struct aead_request *req, u32 flags)
 312{
 313	struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
 314	struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx;
 315
 316	if (gctx->cryptlen)
 317		return gcm_hash_update(req, gcm_hash_crypt_done,
 318				       gctx->src, gctx->cryptlen, flags) ?:
 319		       gcm_hash_crypt_continue(req, flags);
 320
 321	return gcm_hash_crypt_remain_continue(req, flags);
 322}
 323
 324static void gcm_hash_assoc_remain_done(void *data, int err)
 325{
 326	struct aead_request *req = data;
 327
 328	if (err)
 329		goto out;
 330
 331	err = gcm_hash_assoc_remain_continue(req, 0);
 332	if (err == -EINPROGRESS)
 333		return;
 334
 335out:
 336	aead_request_complete(req, err);
 337}
 338
 339static int gcm_hash_assoc_continue(struct aead_request *req, u32 flags)
 340{
 341	unsigned int remain;
 342
 343	remain = gcm_remain(req->assoclen);
 344	if (remain)
 345		return gcm_hash_remain(req, remain,
 346				       gcm_hash_assoc_remain_done, flags) ?:
 347		       gcm_hash_assoc_remain_continue(req, flags);
 348
 349	return gcm_hash_assoc_remain_continue(req, flags);
 350}
 351
 352static void gcm_hash_assoc_done(void *data, int err)
 353{
 354	struct aead_request *req = data;
 355
 356	if (err)
 357		goto out;
 358
 359	err = gcm_hash_assoc_continue(req, 0);
 360	if (err == -EINPROGRESS)
 361		return;
 362
 363out:
 364	aead_request_complete(req, err);
 365}
 366
 367static int gcm_hash_init_continue(struct aead_request *req, u32 flags)
 368{
 369	if (req->assoclen)
 370		return gcm_hash_update(req, gcm_hash_assoc_done,
 371				       req->src, req->assoclen, flags) ?:
 372		       gcm_hash_assoc_continue(req, flags);
 373
 374	return gcm_hash_assoc_remain_continue(req, flags);
 375}
 376
 377static void gcm_hash_init_done(void *data, int err)
 378{
 379	struct aead_request *req = data;
 380
 381	if (err)
 382		goto out;
 383
 384	err = gcm_hash_init_continue(req, 0);
 385	if (err == -EINPROGRESS)
 386		return;
 387
 388out:
 389	aead_request_complete(req, err);
 390}
 391
 392static int gcm_hash(struct aead_request *req, u32 flags)
 393{
 394	struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
 395	struct ahash_request *ahreq = &pctx->u.ahreq;
 396	struct crypto_gcm_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
 397
 398	ahash_request_set_tfm(ahreq, ctx->ghash);
 399
 400	ahash_request_set_callback(ahreq, flags, gcm_hash_init_done, req);
 401	return crypto_ahash_init(ahreq) ?:
 402	       gcm_hash_init_continue(req, flags);
 403}
 404
 405static int gcm_enc_copy_hash(struct aead_request *req, u32 flags)
 406{
 407	struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
 408	struct crypto_aead *aead = crypto_aead_reqtfm(req);
 409	u8 *auth_tag = pctx->auth_tag;
 410
 411	crypto_xor(auth_tag, pctx->iauth_tag, 16);
 412	scatterwalk_map_and_copy(auth_tag, req->dst,
 413				 req->assoclen + req->cryptlen,
 414				 crypto_aead_authsize(aead), 1);
 415	return 0;
 416}
 417
 418static int gcm_encrypt_continue(struct aead_request *req, u32 flags)
 419{
 420	struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
 421	struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx;
 422
 423	gctx->src = sg_next(req->src == req->dst ? pctx->src : pctx->dst);
 424	gctx->cryptlen = req->cryptlen;
 425	gctx->complete = gcm_enc_copy_hash;
 426
 427	return gcm_hash(req, flags);
 428}
 429
 430static void gcm_encrypt_done(void *data, int err)
 431{
 432	struct aead_request *req = data;
 433
 434	if (err)
 435		goto out;
 436
 437	err = gcm_encrypt_continue(req, 0);
 438	if (err == -EINPROGRESS)
 439		return;
 440
 441out:
 442	aead_request_complete(req, err);
 443}
 444
 445static int crypto_gcm_encrypt(struct aead_request *req)
 446{
 447	struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
 448	struct skcipher_request *skreq = &pctx->u.skreq;
 449	u32 flags = aead_request_flags(req);
 450
 451	crypto_gcm_init_common(req);
 452	crypto_gcm_init_crypt(req, req->cryptlen);
 453	skcipher_request_set_callback(skreq, flags, gcm_encrypt_done, req);
 454
 455	return crypto_skcipher_encrypt(skreq) ?:
 456	       gcm_encrypt_continue(req, flags);
 457}
 458
 459static int crypto_gcm_verify(struct aead_request *req)
 460{
 461	struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
 462	struct crypto_aead *aead = crypto_aead_reqtfm(req);
 463	u8 *auth_tag = pctx->auth_tag;
 464	u8 *iauth_tag = pctx->iauth_tag;
 465	unsigned int authsize = crypto_aead_authsize(aead);
 466	unsigned int cryptlen = req->cryptlen - authsize;
 467
 468	crypto_xor(auth_tag, iauth_tag, 16);
 469	scatterwalk_map_and_copy(iauth_tag, req->src,
 470				 req->assoclen + cryptlen, authsize, 0);
 471	return crypto_memneq(iauth_tag, auth_tag, authsize) ? -EBADMSG : 0;
 472}
 473
 474static void gcm_decrypt_done(void *data, int err)
 475{
 476	struct aead_request *req = data;
 477
 478	if (!err)
 479		err = crypto_gcm_verify(req);
 480
 481	aead_request_complete(req, err);
 482}
 483
 484static int gcm_dec_hash_continue(struct aead_request *req, u32 flags)
 485{
 486	struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
 487	struct skcipher_request *skreq = &pctx->u.skreq;
 488	struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx;
 489
 490	crypto_gcm_init_crypt(req, gctx->cryptlen);
 491	skcipher_request_set_callback(skreq, flags, gcm_decrypt_done, req);
 492	return crypto_skcipher_decrypt(skreq) ?: crypto_gcm_verify(req);
 493}
 494
 495static int crypto_gcm_decrypt(struct aead_request *req)
 496{
 497	struct crypto_aead *aead = crypto_aead_reqtfm(req);
 498	struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
 499	struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx;
 500	unsigned int authsize = crypto_aead_authsize(aead);
 501	unsigned int cryptlen = req->cryptlen;
 502	u32 flags = aead_request_flags(req);
 503
 504	cryptlen -= authsize;
 505
 506	crypto_gcm_init_common(req);
 507
 508	gctx->src = sg_next(pctx->src);
 509	gctx->cryptlen = cryptlen;
 510	gctx->complete = gcm_dec_hash_continue;
 511
 512	return gcm_hash(req, flags);
 513}
 514
 515static int crypto_gcm_init_tfm(struct crypto_aead *tfm)
 516{
 517	struct aead_instance *inst = aead_alg_instance(tfm);
 518	struct gcm_instance_ctx *ictx = aead_instance_ctx(inst);
 519	struct crypto_gcm_ctx *ctx = crypto_aead_ctx(tfm);
 520	struct crypto_skcipher *ctr;
 521	struct crypto_ahash *ghash;
 522	unsigned long align;
 523	int err;
 524
 525	ghash = crypto_spawn_ahash(&ictx->ghash);
 526	if (IS_ERR(ghash))
 527		return PTR_ERR(ghash);
 528
 529	ctr = crypto_spawn_skcipher(&ictx->ctr);
 530	err = PTR_ERR(ctr);
 531	if (IS_ERR(ctr))
 532		goto err_free_hash;
 533
 534	ctx->ctr = ctr;
 535	ctx->ghash = ghash;
 536
 537	align = crypto_aead_alignmask(tfm);
 538	align &= ~(crypto_tfm_ctx_alignment() - 1);
 539	crypto_aead_set_reqsize(tfm,
 540		align + offsetof(struct crypto_gcm_req_priv_ctx, u) +
 541		max(sizeof(struct skcipher_request) +
 542		    crypto_skcipher_reqsize(ctr),
 543		    sizeof(struct ahash_request) +
 544		    crypto_ahash_reqsize(ghash)));
 545
 546	return 0;
 547
 548err_free_hash:
 549	crypto_free_ahash(ghash);
 550	return err;
 551}
 552
 553static void crypto_gcm_exit_tfm(struct crypto_aead *tfm)
 554{
 555	struct crypto_gcm_ctx *ctx = crypto_aead_ctx(tfm);
 556
 557	crypto_free_ahash(ctx->ghash);
 558	crypto_free_skcipher(ctx->ctr);
 559}
 560
 561static void crypto_gcm_free(struct aead_instance *inst)
 562{
 563	struct gcm_instance_ctx *ctx = aead_instance_ctx(inst);
 564
 565	crypto_drop_skcipher(&ctx->ctr);
 566	crypto_drop_ahash(&ctx->ghash);
 567	kfree(inst);
 568}
 569
 570static int crypto_gcm_create_common(struct crypto_template *tmpl,
 571				    struct rtattr **tb,
 572				    const char *ctr_name,
 573				    const char *ghash_name)
 574{
 575	struct skcipher_alg_common *ctr;
 576	u32 mask;
 577	struct aead_instance *inst;
 578	struct gcm_instance_ctx *ctx;
 579	struct hash_alg_common *ghash;
 580	int err;
 581
 582	err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_AEAD, &mask);
 583	if (err)
 584		return err;
 585
 586	inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
 587	if (!inst)
 588		return -ENOMEM;
 589	ctx = aead_instance_ctx(inst);
 590
 591	err = crypto_grab_ahash(&ctx->ghash, aead_crypto_instance(inst),
 592				ghash_name, 0, mask);
 593	if (err)
 594		goto err_free_inst;
 595	ghash = crypto_spawn_ahash_alg(&ctx->ghash);
 596
 597	err = -EINVAL;
 598	if (strcmp(ghash->base.cra_name, "ghash") != 0 ||
 599	    ghash->digestsize != 16)
 600		goto err_free_inst;
 601
 602	err = crypto_grab_skcipher(&ctx->ctr, aead_crypto_instance(inst),
 603				   ctr_name, 0, mask);
 604	if (err)
 605		goto err_free_inst;
 606	ctr = crypto_spawn_skcipher_alg_common(&ctx->ctr);
 607
 608	/* The skcipher algorithm must be CTR mode, using 16-byte blocks. */
 609	err = -EINVAL;
 610	if (strncmp(ctr->base.cra_name, "ctr(", 4) != 0 ||
 611	    ctr->ivsize != 16 || ctr->base.cra_blocksize != 1)
 612		goto err_free_inst;
 613
 614	err = -ENAMETOOLONG;
 615	if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
 616		     "gcm(%s", ctr->base.cra_name + 4) >= CRYPTO_MAX_ALG_NAME)
 617		goto err_free_inst;
 618
 619	if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
 620		     "gcm_base(%s,%s)", ctr->base.cra_driver_name,
 621		     ghash->base.cra_driver_name) >=
 622	    CRYPTO_MAX_ALG_NAME)
 623		goto err_free_inst;
 624
 625	inst->alg.base.cra_priority = (ghash->base.cra_priority +
 626				       ctr->base.cra_priority) / 2;
 627	inst->alg.base.cra_blocksize = 1;
 628	inst->alg.base.cra_alignmask = ctr->base.cra_alignmask;
 629	inst->alg.base.cra_ctxsize = sizeof(struct crypto_gcm_ctx);
 630	inst->alg.ivsize = GCM_AES_IV_SIZE;
 631	inst->alg.chunksize = ctr->chunksize;
 632	inst->alg.maxauthsize = 16;
 633	inst->alg.init = crypto_gcm_init_tfm;
 634	inst->alg.exit = crypto_gcm_exit_tfm;
 635	inst->alg.setkey = crypto_gcm_setkey;
 636	inst->alg.setauthsize = crypto_gcm_setauthsize;
 637	inst->alg.encrypt = crypto_gcm_encrypt;
 638	inst->alg.decrypt = crypto_gcm_decrypt;
 639
 640	inst->free = crypto_gcm_free;
 641
 642	err = aead_register_instance(tmpl, inst);
 643	if (err) {
 644err_free_inst:
 645		crypto_gcm_free(inst);
 646	}
 647	return err;
 648}
 649
 650static int crypto_gcm_create(struct crypto_template *tmpl, struct rtattr **tb)
 651{
 652	const char *cipher_name;
 653	char ctr_name[CRYPTO_MAX_ALG_NAME];
 654
 655	cipher_name = crypto_attr_alg_name(tb[1]);
 656	if (IS_ERR(cipher_name))
 657		return PTR_ERR(cipher_name);
 658
 659	if (snprintf(ctr_name, CRYPTO_MAX_ALG_NAME, "ctr(%s)", cipher_name) >=
 660	    CRYPTO_MAX_ALG_NAME)
 661		return -ENAMETOOLONG;
 662
 663	return crypto_gcm_create_common(tmpl, tb, ctr_name, "ghash");
 664}
 665
 666static int crypto_gcm_base_create(struct crypto_template *tmpl,
 667				  struct rtattr **tb)
 668{
 669	const char *ctr_name;
 670	const char *ghash_name;
 671
 672	ctr_name = crypto_attr_alg_name(tb[1]);
 673	if (IS_ERR(ctr_name))
 674		return PTR_ERR(ctr_name);
 675
 676	ghash_name = crypto_attr_alg_name(tb[2]);
 677	if (IS_ERR(ghash_name))
 678		return PTR_ERR(ghash_name);
 679
 680	return crypto_gcm_create_common(tmpl, tb, ctr_name, ghash_name);
 681}
 682
 683static int crypto_rfc4106_setkey(struct crypto_aead *parent, const u8 *key,
 684				 unsigned int keylen)
 685{
 686	struct crypto_rfc4106_ctx *ctx = crypto_aead_ctx(parent);
 687	struct crypto_aead *child = ctx->child;
 688
 689	if (keylen < 4)
 690		return -EINVAL;
 691
 692	keylen -= 4;
 693	memcpy(ctx->nonce, key + keylen, 4);
 694
 695	crypto_aead_clear_flags(child, CRYPTO_TFM_REQ_MASK);
 696	crypto_aead_set_flags(child, crypto_aead_get_flags(parent) &
 697				     CRYPTO_TFM_REQ_MASK);
 698	return crypto_aead_setkey(child, key, keylen);
 699}
 700
 701static int crypto_rfc4106_setauthsize(struct crypto_aead *parent,
 702				      unsigned int authsize)
 703{
 704	struct crypto_rfc4106_ctx *ctx = crypto_aead_ctx(parent);
 705	int err;
 706
 707	err = crypto_rfc4106_check_authsize(authsize);
 708	if (err)
 709		return err;
 710
 711	return crypto_aead_setauthsize(ctx->child, authsize);
 712}
 713
 714static struct aead_request *crypto_rfc4106_crypt(struct aead_request *req)
 715{
 716	struct crypto_rfc4106_req_ctx *rctx = aead_request_ctx(req);
 717	struct crypto_aead *aead = crypto_aead_reqtfm(req);
 718	struct crypto_rfc4106_ctx *ctx = crypto_aead_ctx(aead);
 719	struct aead_request *subreq = &rctx->subreq;
 720	struct crypto_aead *child = ctx->child;
 721	struct scatterlist *sg;
 722	u8 *iv = PTR_ALIGN((u8 *)(subreq + 1) + crypto_aead_reqsize(child),
 723			   crypto_aead_alignmask(child) + 1);
 724
 725	scatterwalk_map_and_copy(iv + GCM_AES_IV_SIZE, req->src, 0, req->assoclen - 8, 0);
 726
 727	memcpy(iv, ctx->nonce, 4);
 728	memcpy(iv + 4, req->iv, 8);
 729
 730	sg_init_table(rctx->src, 3);
 731	sg_set_buf(rctx->src, iv + GCM_AES_IV_SIZE, req->assoclen - 8);
 732	sg = scatterwalk_ffwd(rctx->src + 1, req->src, req->assoclen);
 733	if (sg != rctx->src + 1)
 734		sg_chain(rctx->src, 2, sg);
 735
 736	if (req->src != req->dst) {
 737		sg_init_table(rctx->dst, 3);
 738		sg_set_buf(rctx->dst, iv + GCM_AES_IV_SIZE, req->assoclen - 8);
 739		sg = scatterwalk_ffwd(rctx->dst + 1, req->dst, req->assoclen);
 740		if (sg != rctx->dst + 1)
 741			sg_chain(rctx->dst, 2, sg);
 742	}
 743
 744	aead_request_set_tfm(subreq, child);
 745	aead_request_set_callback(subreq, req->base.flags, req->base.complete,
 746				  req->base.data);
 747	aead_request_set_crypt(subreq, rctx->src,
 748			       req->src == req->dst ? rctx->src : rctx->dst,
 749			       req->cryptlen, iv);
 750	aead_request_set_ad(subreq, req->assoclen - 8);
 751
 752	return subreq;
 753}
 754
 755static int crypto_rfc4106_encrypt(struct aead_request *req)
 756{
 757	int err;
 758
 759	err = crypto_ipsec_check_assoclen(req->assoclen);
 760	if (err)
 761		return err;
 762
 763	req = crypto_rfc4106_crypt(req);
 764
 765	return crypto_aead_encrypt(req);
 766}
 767
 768static int crypto_rfc4106_decrypt(struct aead_request *req)
 769{
 770	int err;
 771
 772	err = crypto_ipsec_check_assoclen(req->assoclen);
 773	if (err)
 774		return err;
 775
 776	req = crypto_rfc4106_crypt(req);
 777
 778	return crypto_aead_decrypt(req);
 779}
 780
 781static int crypto_rfc4106_init_tfm(struct crypto_aead *tfm)
 782{
 783	struct aead_instance *inst = aead_alg_instance(tfm);
 784	struct crypto_aead_spawn *spawn = aead_instance_ctx(inst);
 785	struct crypto_rfc4106_ctx *ctx = crypto_aead_ctx(tfm);
 786	struct crypto_aead *aead;
 787	unsigned long align;
 788
 789	aead = crypto_spawn_aead(spawn);
 790	if (IS_ERR(aead))
 791		return PTR_ERR(aead);
 792
 793	ctx->child = aead;
 794
 795	align = crypto_aead_alignmask(aead);
 796	align &= ~(crypto_tfm_ctx_alignment() - 1);
 797	crypto_aead_set_reqsize(
 798		tfm,
 799		sizeof(struct crypto_rfc4106_req_ctx) +
 800		ALIGN(crypto_aead_reqsize(aead), crypto_tfm_ctx_alignment()) +
 801		align + 24);
 802
 803	return 0;
 804}
 805
 806static void crypto_rfc4106_exit_tfm(struct crypto_aead *tfm)
 807{
 808	struct crypto_rfc4106_ctx *ctx = crypto_aead_ctx(tfm);
 809
 810	crypto_free_aead(ctx->child);
 811}
 812
 813static void crypto_rfc4106_free(struct aead_instance *inst)
 814{
 815	crypto_drop_aead(aead_instance_ctx(inst));
 816	kfree(inst);
 817}
 818
 819static int crypto_rfc4106_create(struct crypto_template *tmpl,
 820				 struct rtattr **tb)
 821{
 822	u32 mask;
 823	struct aead_instance *inst;
 824	struct crypto_aead_spawn *spawn;
 825	struct aead_alg *alg;
 826	int err;
 827
 828	err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_AEAD, &mask);
 829	if (err)
 830		return err;
 831
 832	inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
 833	if (!inst)
 834		return -ENOMEM;
 835
 836	spawn = aead_instance_ctx(inst);
 837	err = crypto_grab_aead(spawn, aead_crypto_instance(inst),
 838			       crypto_attr_alg_name(tb[1]), 0, mask);
 839	if (err)
 840		goto err_free_inst;
 841
 842	alg = crypto_spawn_aead_alg(spawn);
 843
 844	err = -EINVAL;
 845
 846	/* Underlying IV size must be 12. */
 847	if (crypto_aead_alg_ivsize(alg) != GCM_AES_IV_SIZE)
 848		goto err_free_inst;
 849
 850	/* Not a stream cipher? */
 851	if (alg->base.cra_blocksize != 1)
 852		goto err_free_inst;
 853
 854	err = -ENAMETOOLONG;
 855	if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
 856		     "rfc4106(%s)", alg->base.cra_name) >=
 857	    CRYPTO_MAX_ALG_NAME ||
 858	    snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
 859		     "rfc4106(%s)", alg->base.cra_driver_name) >=
 860	    CRYPTO_MAX_ALG_NAME)
 861		goto err_free_inst;
 862
 863	inst->alg.base.cra_priority = alg->base.cra_priority;
 864	inst->alg.base.cra_blocksize = 1;
 865	inst->alg.base.cra_alignmask = alg->base.cra_alignmask;
 866
 867	inst->alg.base.cra_ctxsize = sizeof(struct crypto_rfc4106_ctx);
 868
 869	inst->alg.ivsize = GCM_RFC4106_IV_SIZE;
 870	inst->alg.chunksize = crypto_aead_alg_chunksize(alg);
 871	inst->alg.maxauthsize = crypto_aead_alg_maxauthsize(alg);
 872
 873	inst->alg.init = crypto_rfc4106_init_tfm;
 874	inst->alg.exit = crypto_rfc4106_exit_tfm;
 875
 876	inst->alg.setkey = crypto_rfc4106_setkey;
 877	inst->alg.setauthsize = crypto_rfc4106_setauthsize;
 878	inst->alg.encrypt = crypto_rfc4106_encrypt;
 879	inst->alg.decrypt = crypto_rfc4106_decrypt;
 880
 881	inst->free = crypto_rfc4106_free;
 882
 883	err = aead_register_instance(tmpl, inst);
 884	if (err) {
 885err_free_inst:
 886		crypto_rfc4106_free(inst);
 887	}
 888	return err;
 889}
 890
 891static int crypto_rfc4543_setkey(struct crypto_aead *parent, const u8 *key,
 892				 unsigned int keylen)
 893{
 894	struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(parent);
 895	struct crypto_aead *child = ctx->child;
 896
 897	if (keylen < 4)
 898		return -EINVAL;
 899
 900	keylen -= 4;
 901	memcpy(ctx->nonce, key + keylen, 4);
 902
 903	crypto_aead_clear_flags(child, CRYPTO_TFM_REQ_MASK);
 904	crypto_aead_set_flags(child, crypto_aead_get_flags(parent) &
 905				     CRYPTO_TFM_REQ_MASK);
 906	return crypto_aead_setkey(child, key, keylen);
 907}
 908
 909static int crypto_rfc4543_setauthsize(struct crypto_aead *parent,
 910				      unsigned int authsize)
 911{
 912	struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(parent);
 913
 914	if (authsize != 16)
 915		return -EINVAL;
 916
 917	return crypto_aead_setauthsize(ctx->child, authsize);
 918}
 919
 920static int crypto_rfc4543_crypt(struct aead_request *req, bool enc)
 921{
 922	struct crypto_aead *aead = crypto_aead_reqtfm(req);
 923	struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(aead);
 924	struct crypto_rfc4543_req_ctx *rctx = aead_request_ctx(req);
 925	struct aead_request *subreq = &rctx->subreq;
 926	unsigned int authsize = crypto_aead_authsize(aead);
 927	u8 *iv = PTR_ALIGN((u8 *)(rctx + 1) + crypto_aead_reqsize(ctx->child),
 928			   crypto_aead_alignmask(ctx->child) + 1);
 929
 930	if (req->src != req->dst) {
 931		unsigned int nbytes = req->assoclen + req->cryptlen -
 932				      (enc ? 0 : authsize);
 933
 934		memcpy_sglist(req->dst, req->src, nbytes);
 935	}
 936
 937	memcpy(iv, ctx->nonce, 4);
 938	memcpy(iv + 4, req->iv, 8);
 939
 940	aead_request_set_tfm(subreq, ctx->child);
 941	aead_request_set_callback(subreq, req->base.flags,
 942				  req->base.complete, req->base.data);
 943	aead_request_set_crypt(subreq, req->src, req->dst,
 944			       enc ? 0 : authsize, iv);
 945	aead_request_set_ad(subreq, req->assoclen + req->cryptlen -
 946				    subreq->cryptlen);
 947
 948	return enc ? crypto_aead_encrypt(subreq) : crypto_aead_decrypt(subreq);
 949}
 950
 951static int crypto_rfc4543_encrypt(struct aead_request *req)
 952{
 953	return crypto_ipsec_check_assoclen(req->assoclen) ?:
 954	       crypto_rfc4543_crypt(req, true);
 955}
 956
 957static int crypto_rfc4543_decrypt(struct aead_request *req)
 958{
 959	return crypto_ipsec_check_assoclen(req->assoclen) ?:
 960	       crypto_rfc4543_crypt(req, false);
 961}
 962
 963static int crypto_rfc4543_init_tfm(struct crypto_aead *tfm)
 964{
 965	struct aead_instance *inst = aead_alg_instance(tfm);
 966	struct crypto_rfc4543_instance_ctx *ictx = aead_instance_ctx(inst);
 967	struct crypto_aead_spawn *spawn = &ictx->aead;
 968	struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(tfm);
 969	struct crypto_aead *aead;
 970	unsigned long align;
 971
 972	aead = crypto_spawn_aead(spawn);
 973	if (IS_ERR(aead))
 974		return PTR_ERR(aead);
 975
 976	ctx->child = aead;
 977
 978	align = crypto_aead_alignmask(aead);
 979	align &= ~(crypto_tfm_ctx_alignment() - 1);
 980	crypto_aead_set_reqsize(
 981		tfm,
 982		sizeof(struct crypto_rfc4543_req_ctx) +
 983		ALIGN(crypto_aead_reqsize(aead), crypto_tfm_ctx_alignment()) +
 984		align + GCM_AES_IV_SIZE);
 985
 986	return 0;
 987}
 988
 989static void crypto_rfc4543_exit_tfm(struct crypto_aead *tfm)
 990{
 991	struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(tfm);
 992
 993	crypto_free_aead(ctx->child);
 994}
 995
 996static void crypto_rfc4543_free(struct aead_instance *inst)
 997{
 998	struct crypto_rfc4543_instance_ctx *ctx = aead_instance_ctx(inst);
 999
1000	crypto_drop_aead(&ctx->aead);
1001
1002	kfree(inst);
1003}
1004
1005static int crypto_rfc4543_create(struct crypto_template *tmpl,
1006				struct rtattr **tb)
1007{
1008	u32 mask;
1009	struct aead_instance *inst;
1010	struct aead_alg *alg;
1011	struct crypto_rfc4543_instance_ctx *ctx;
1012	int err;
1013
1014	err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_AEAD, &mask);
1015	if (err)
1016		return err;
1017
1018	inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
1019	if (!inst)
1020		return -ENOMEM;
1021
1022	ctx = aead_instance_ctx(inst);
1023	err = crypto_grab_aead(&ctx->aead, aead_crypto_instance(inst),
1024			       crypto_attr_alg_name(tb[1]), 0, mask);
1025	if (err)
1026		goto err_free_inst;
1027
1028	alg = crypto_spawn_aead_alg(&ctx->aead);
1029
1030	err = -EINVAL;
1031
1032	/* Underlying IV size must be 12. */
1033	if (crypto_aead_alg_ivsize(alg) != GCM_AES_IV_SIZE)
1034		goto err_free_inst;
1035
1036	/* Not a stream cipher? */
1037	if (alg->base.cra_blocksize != 1)
1038		goto err_free_inst;
1039
1040	err = -ENAMETOOLONG;
1041	if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
1042		     "rfc4543(%s)", alg->base.cra_name) >=
1043	    CRYPTO_MAX_ALG_NAME ||
1044	    snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
1045		     "rfc4543(%s)", alg->base.cra_driver_name) >=
1046	    CRYPTO_MAX_ALG_NAME)
1047		goto err_free_inst;
1048
1049	inst->alg.base.cra_priority = alg->base.cra_priority;
1050	inst->alg.base.cra_blocksize = 1;
1051	inst->alg.base.cra_alignmask = alg->base.cra_alignmask;
1052
1053	inst->alg.base.cra_ctxsize = sizeof(struct crypto_rfc4543_ctx);
1054
1055	inst->alg.ivsize = GCM_RFC4543_IV_SIZE;
1056	inst->alg.chunksize = crypto_aead_alg_chunksize(alg);
1057	inst->alg.maxauthsize = crypto_aead_alg_maxauthsize(alg);
1058
1059	inst->alg.init = crypto_rfc4543_init_tfm;
1060	inst->alg.exit = crypto_rfc4543_exit_tfm;
1061
1062	inst->alg.setkey = crypto_rfc4543_setkey;
1063	inst->alg.setauthsize = crypto_rfc4543_setauthsize;
1064	inst->alg.encrypt = crypto_rfc4543_encrypt;
1065	inst->alg.decrypt = crypto_rfc4543_decrypt;
1066
1067	inst->free = crypto_rfc4543_free;
1068
1069	err = aead_register_instance(tmpl, inst);
1070	if (err) {
1071err_free_inst:
1072		crypto_rfc4543_free(inst);
1073	}
1074	return err;
1075}
1076
1077static struct crypto_template crypto_gcm_tmpls[] = {
1078	{
1079		.name = "gcm_base",
1080		.create = crypto_gcm_base_create,
1081		.module = THIS_MODULE,
1082	}, {
1083		.name = "gcm",
1084		.create = crypto_gcm_create,
1085		.module = THIS_MODULE,
1086	}, {
1087		.name = "rfc4106",
1088		.create = crypto_rfc4106_create,
1089		.module = THIS_MODULE,
1090	}, {
1091		.name = "rfc4543",
1092		.create = crypto_rfc4543_create,
1093		.module = THIS_MODULE,
1094	},
1095};
1096
1097static int __init crypto_gcm_module_init(void)
1098{
1099	int err;
1100
1101	gcm_zeroes = kzalloc(sizeof(*gcm_zeroes), GFP_KERNEL);
1102	if (!gcm_zeroes)
1103		return -ENOMEM;
1104
1105	sg_init_one(&gcm_zeroes->sg, gcm_zeroes->buf, sizeof(gcm_zeroes->buf));
1106
1107	err = crypto_register_templates(crypto_gcm_tmpls,
1108					ARRAY_SIZE(crypto_gcm_tmpls));
1109	if (err)
1110		kfree(gcm_zeroes);
1111
1112	return err;
1113}
1114
1115static void __exit crypto_gcm_module_exit(void)
1116{
1117	kfree(gcm_zeroes);
1118	crypto_unregister_templates(crypto_gcm_tmpls,
1119				    ARRAY_SIZE(crypto_gcm_tmpls));
1120}
1121
1122module_init(crypto_gcm_module_init);
1123module_exit(crypto_gcm_module_exit);
1124
1125MODULE_LICENSE("GPL");
1126MODULE_DESCRIPTION("Galois/Counter Mode");
1127MODULE_AUTHOR("Mikko Herranen <mh1@iki.fi>");
1128MODULE_ALIAS_CRYPTO("gcm_base");
1129MODULE_ALIAS_CRYPTO("rfc4106");
1130MODULE_ALIAS_CRYPTO("rfc4543");
1131MODULE_ALIAS_CRYPTO("gcm");