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   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/null.h>
  13#include <crypto/scatterwalk.h>
  14#include <crypto/gcm.h>
  15#include <crypto/hash.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
  22struct gcm_instance_ctx {
  23	struct crypto_skcipher_spawn ctr;
  24	struct crypto_ahash_spawn ghash;
  25};
  26
  27struct crypto_gcm_ctx {
  28	struct crypto_skcipher *ctr;
  29	struct crypto_ahash *ghash;
  30};
  31
  32struct crypto_rfc4106_ctx {
  33	struct crypto_aead *child;
  34	u8 nonce[4];
  35};
  36
  37struct crypto_rfc4106_req_ctx {
  38	struct scatterlist src[3];
  39	struct scatterlist dst[3];
  40	struct aead_request subreq;
  41};
  42
  43struct crypto_rfc4543_instance_ctx {
  44	struct crypto_aead_spawn aead;
  45};
  46
  47struct crypto_rfc4543_ctx {
  48	struct crypto_aead *child;
  49	struct crypto_sync_skcipher *null;
  50	u8 nonce[4];
  51};
  52
  53struct crypto_rfc4543_req_ctx {
  54	struct aead_request subreq;
  55};
  56
  57struct crypto_gcm_ghash_ctx {
  58	unsigned int cryptlen;
  59	struct scatterlist *src;
  60	int (*complete)(struct aead_request *req, u32 flags);
  61};
  62
  63struct crypto_gcm_req_priv_ctx {
  64	u8 iv[16];
  65	u8 auth_tag[16];
  66	u8 iauth_tag[16];
  67	struct scatterlist src[3];
  68	struct scatterlist dst[3];
  69	struct scatterlist sg;
  70	struct crypto_gcm_ghash_ctx ghash_ctx;
  71	union {
  72		struct ahash_request ahreq;
  73		struct skcipher_request skreq;
  74	} u;
  75};
  76
  77static struct {
  78	u8 buf[16];
  79	struct scatterlist sg;
  80} *gcm_zeroes;
  81
  82static int crypto_rfc4543_copy_src_to_dst(struct aead_request *req, bool enc);
  83
  84static inline struct crypto_gcm_req_priv_ctx *crypto_gcm_reqctx(
  85	struct aead_request *req)
  86{
  87	unsigned long align = crypto_aead_alignmask(crypto_aead_reqtfm(req));
  88
  89	return (void *)PTR_ALIGN((u8 *)aead_request_ctx(req), align + 1);
  90}
  91
  92static int crypto_gcm_setkey(struct crypto_aead *aead, const u8 *key,
  93			     unsigned int keylen)
  94{
  95	struct crypto_gcm_ctx *ctx = crypto_aead_ctx(aead);
  96	struct crypto_ahash *ghash = ctx->ghash;
  97	struct crypto_skcipher *ctr = ctx->ctr;
  98	struct {
  99		be128 hash;
 100		u8 iv[16];
 101
 102		struct crypto_wait wait;
 103
 104		struct scatterlist sg[1];
 105		struct skcipher_request req;
 106	} *data;
 107	int err;
 108
 109	crypto_skcipher_clear_flags(ctr, CRYPTO_TFM_REQ_MASK);
 110	crypto_skcipher_set_flags(ctr, crypto_aead_get_flags(aead) &
 111				       CRYPTO_TFM_REQ_MASK);
 112	err = crypto_skcipher_setkey(ctr, key, keylen);
 113	if (err)
 114		return err;
 115
 116	data = kzalloc(sizeof(*data) + crypto_skcipher_reqsize(ctr),
 117		       GFP_KERNEL);
 118	if (!data)
 119		return -ENOMEM;
 120
 121	crypto_init_wait(&data->wait);
 122	sg_init_one(data->sg, &data->hash, sizeof(data->hash));
 123	skcipher_request_set_tfm(&data->req, ctr);
 124	skcipher_request_set_callback(&data->req, CRYPTO_TFM_REQ_MAY_SLEEP |
 125						  CRYPTO_TFM_REQ_MAY_BACKLOG,
 126				      crypto_req_done,
 127				      &data->wait);
 128	skcipher_request_set_crypt(&data->req, data->sg, data->sg,
 129				   sizeof(data->hash), data->iv);
 130
 131	err = crypto_wait_req(crypto_skcipher_encrypt(&data->req),
 132							&data->wait);
 133
 134	if (err)
 135		goto out;
 136
 137	crypto_ahash_clear_flags(ghash, CRYPTO_TFM_REQ_MASK);
 138	crypto_ahash_set_flags(ghash, crypto_aead_get_flags(aead) &
 139			       CRYPTO_TFM_REQ_MASK);
 140	err = crypto_ahash_setkey(ghash, (u8 *)&data->hash, sizeof(be128));
 141out:
 142	kfree_sensitive(data);
 143	return err;
 144}
 145
 146static int crypto_gcm_setauthsize(struct crypto_aead *tfm,
 147				  unsigned int authsize)
 148{
 149	return crypto_gcm_check_authsize(authsize);
 150}
 151
 152static void crypto_gcm_init_common(struct aead_request *req)
 153{
 154	struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
 155	__be32 counter = cpu_to_be32(1);
 156	struct scatterlist *sg;
 157
 158	memset(pctx->auth_tag, 0, sizeof(pctx->auth_tag));
 159	memcpy(pctx->iv, req->iv, GCM_AES_IV_SIZE);
 160	memcpy(pctx->iv + GCM_AES_IV_SIZE, &counter, 4);
 161
 162	sg_init_table(pctx->src, 3);
 163	sg_set_buf(pctx->src, pctx->auth_tag, sizeof(pctx->auth_tag));
 164	sg = scatterwalk_ffwd(pctx->src + 1, req->src, req->assoclen);
 165	if (sg != pctx->src + 1)
 166		sg_chain(pctx->src, 2, sg);
 167
 168	if (req->src != req->dst) {
 169		sg_init_table(pctx->dst, 3);
 170		sg_set_buf(pctx->dst, pctx->auth_tag, sizeof(pctx->auth_tag));
 171		sg = scatterwalk_ffwd(pctx->dst + 1, req->dst, req->assoclen);
 172		if (sg != pctx->dst + 1)
 173			sg_chain(pctx->dst, 2, sg);
 174	}
 175}
 176
 177static void crypto_gcm_init_crypt(struct aead_request *req,
 178				  unsigned int cryptlen)
 179{
 180	struct crypto_aead *aead = crypto_aead_reqtfm(req);
 181	struct crypto_gcm_ctx *ctx = crypto_aead_ctx(aead);
 182	struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
 183	struct skcipher_request *skreq = &pctx->u.skreq;
 184	struct scatterlist *dst;
 185
 186	dst = req->src == req->dst ? pctx->src : pctx->dst;
 187
 188	skcipher_request_set_tfm(skreq, ctx->ctr);
 189	skcipher_request_set_crypt(skreq, pctx->src, dst,
 190				     cryptlen + sizeof(pctx->auth_tag),
 191				     pctx->iv);
 192}
 193
 194static inline unsigned int gcm_remain(unsigned int len)
 195{
 196	len &= 0xfU;
 197	return len ? 16 - len : 0;
 198}
 199
 200static void gcm_hash_len_done(void *data, int err);
 201
 202static int gcm_hash_update(struct aead_request *req,
 203			   crypto_completion_t compl,
 204			   struct scatterlist *src,
 205			   unsigned int len, u32 flags)
 206{
 207	struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
 208	struct ahash_request *ahreq = &pctx->u.ahreq;
 209
 210	ahash_request_set_callback(ahreq, flags, compl, req);
 211	ahash_request_set_crypt(ahreq, src, NULL, len);
 212
 213	return crypto_ahash_update(ahreq);
 214}
 215
 216static int gcm_hash_remain(struct aead_request *req,
 217			   unsigned int remain,
 218			   crypto_completion_t compl, u32 flags)
 219{
 220	return gcm_hash_update(req, compl, &gcm_zeroes->sg, remain, flags);
 221}
 222
 223static int gcm_hash_len(struct aead_request *req, u32 flags)
 224{
 225	struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
 226	struct ahash_request *ahreq = &pctx->u.ahreq;
 227	struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx;
 228	be128 lengths;
 229
 230	lengths.a = cpu_to_be64(req->assoclen * 8);
 231	lengths.b = cpu_to_be64(gctx->cryptlen * 8);
 232	memcpy(pctx->iauth_tag, &lengths, 16);
 233	sg_init_one(&pctx->sg, pctx->iauth_tag, 16);
 234	ahash_request_set_callback(ahreq, flags, gcm_hash_len_done, req);
 235	ahash_request_set_crypt(ahreq, &pctx->sg,
 236				pctx->iauth_tag, sizeof(lengths));
 237
 238	return crypto_ahash_finup(ahreq);
 239}
 240
 241static int gcm_hash_len_continue(struct aead_request *req, u32 flags)
 242{
 243	struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
 244	struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx;
 245
 246	return gctx->complete(req, flags);
 247}
 248
 249static void gcm_hash_len_done(void *data, int err)
 250{
 251	struct aead_request *req = data;
 252
 253	if (err)
 254		goto out;
 255
 256	err = gcm_hash_len_continue(req, 0);
 257	if (err == -EINPROGRESS)
 258		return;
 259
 260out:
 261	aead_request_complete(req, err);
 262}
 263
 264static int gcm_hash_crypt_remain_continue(struct aead_request *req, u32 flags)
 265{
 266	return gcm_hash_len(req, flags) ?:
 267	       gcm_hash_len_continue(req, flags);
 268}
 269
 270static void gcm_hash_crypt_remain_done(void *data, int err)
 
 271{
 272	struct aead_request *req = data;
 273
 274	if (err)
 275		goto out;
 276
 277	err = gcm_hash_crypt_remain_continue(req, 0);
 278	if (err == -EINPROGRESS)
 279		return;
 280
 281out:
 282	aead_request_complete(req, err);
 283}
 284
 285static int gcm_hash_crypt_continue(struct aead_request *req, u32 flags)
 286{
 287	struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
 288	struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx;
 289	unsigned int remain;
 290
 291	remain = gcm_remain(gctx->cryptlen);
 292	if (remain)
 293		return gcm_hash_remain(req, remain,
 294				       gcm_hash_crypt_remain_done, flags) ?:
 295		       gcm_hash_crypt_remain_continue(req, flags);
 296
 297	return gcm_hash_crypt_remain_continue(req, flags);
 298}
 299
 300static void gcm_hash_crypt_done(void *data, int err)
 301{
 302	struct aead_request *req = data;
 303
 304	if (err)
 305		goto out;
 306
 307	err = gcm_hash_crypt_continue(req, 0);
 308	if (err == -EINPROGRESS)
 309		return;
 310
 311out:
 312	aead_request_complete(req, err);
 313}
 314
 315static int gcm_hash_assoc_remain_continue(struct aead_request *req, u32 flags)
 316{
 317	struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
 318	struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx;
 319
 320	if (gctx->cryptlen)
 321		return gcm_hash_update(req, gcm_hash_crypt_done,
 322				       gctx->src, gctx->cryptlen, flags) ?:
 323		       gcm_hash_crypt_continue(req, flags);
 324
 325	return gcm_hash_crypt_remain_continue(req, flags);
 326}
 327
 328static void gcm_hash_assoc_remain_done(void *data, int err)
 
 329{
 330	struct aead_request *req = data;
 331
 332	if (err)
 333		goto out;
 334
 335	err = gcm_hash_assoc_remain_continue(req, 0);
 336	if (err == -EINPROGRESS)
 337		return;
 338
 339out:
 340	aead_request_complete(req, err);
 341}
 342
 343static int gcm_hash_assoc_continue(struct aead_request *req, u32 flags)
 344{
 345	unsigned int remain;
 346
 347	remain = gcm_remain(req->assoclen);
 348	if (remain)
 349		return gcm_hash_remain(req, remain,
 350				       gcm_hash_assoc_remain_done, flags) ?:
 351		       gcm_hash_assoc_remain_continue(req, flags);
 352
 353	return gcm_hash_assoc_remain_continue(req, flags);
 354}
 355
 356static void gcm_hash_assoc_done(void *data, int err)
 357{
 358	struct aead_request *req = data;
 359
 360	if (err)
 361		goto out;
 362
 363	err = gcm_hash_assoc_continue(req, 0);
 364	if (err == -EINPROGRESS)
 365		return;
 366
 367out:
 368	aead_request_complete(req, err);
 369}
 370
 371static int gcm_hash_init_continue(struct aead_request *req, u32 flags)
 372{
 373	if (req->assoclen)
 374		return gcm_hash_update(req, gcm_hash_assoc_done,
 375				       req->src, req->assoclen, flags) ?:
 376		       gcm_hash_assoc_continue(req, flags);
 377
 378	return gcm_hash_assoc_remain_continue(req, flags);
 379}
 380
 381static void gcm_hash_init_done(void *data, int err)
 382{
 383	struct aead_request *req = data;
 384
 385	if (err)
 386		goto out;
 387
 388	err = gcm_hash_init_continue(req, 0);
 389	if (err == -EINPROGRESS)
 390		return;
 391
 392out:
 393	aead_request_complete(req, err);
 394}
 395
 396static int gcm_hash(struct aead_request *req, u32 flags)
 397{
 398	struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
 399	struct ahash_request *ahreq = &pctx->u.ahreq;
 400	struct crypto_gcm_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
 401
 402	ahash_request_set_tfm(ahreq, ctx->ghash);
 403
 404	ahash_request_set_callback(ahreq, flags, gcm_hash_init_done, req);
 405	return crypto_ahash_init(ahreq) ?:
 406	       gcm_hash_init_continue(req, flags);
 407}
 408
 409static int gcm_enc_copy_hash(struct aead_request *req, u32 flags)
 410{
 411	struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
 412	struct crypto_aead *aead = crypto_aead_reqtfm(req);
 413	u8 *auth_tag = pctx->auth_tag;
 414
 415	crypto_xor(auth_tag, pctx->iauth_tag, 16);
 416	scatterwalk_map_and_copy(auth_tag, req->dst,
 417				 req->assoclen + req->cryptlen,
 418				 crypto_aead_authsize(aead), 1);
 419	return 0;
 420}
 421
 422static int gcm_encrypt_continue(struct aead_request *req, u32 flags)
 423{
 424	struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
 425	struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx;
 426
 427	gctx->src = sg_next(req->src == req->dst ? pctx->src : pctx->dst);
 428	gctx->cryptlen = req->cryptlen;
 429	gctx->complete = gcm_enc_copy_hash;
 430
 431	return gcm_hash(req, flags);
 432}
 433
 434static void gcm_encrypt_done(void *data, int err)
 435{
 436	struct aead_request *req = data;
 437
 438	if (err)
 439		goto out;
 440
 441	err = gcm_encrypt_continue(req, 0);
 442	if (err == -EINPROGRESS)
 443		return;
 444
 445out:
 446	aead_request_complete(req, err);
 447}
 448
 449static int crypto_gcm_encrypt(struct aead_request *req)
 450{
 451	struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
 452	struct skcipher_request *skreq = &pctx->u.skreq;
 453	u32 flags = aead_request_flags(req);
 454
 455	crypto_gcm_init_common(req);
 456	crypto_gcm_init_crypt(req, req->cryptlen);
 457	skcipher_request_set_callback(skreq, flags, gcm_encrypt_done, req);
 458
 459	return crypto_skcipher_encrypt(skreq) ?:
 460	       gcm_encrypt_continue(req, flags);
 461}
 462
 463static int crypto_gcm_verify(struct aead_request *req)
 464{
 465	struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
 466	struct crypto_aead *aead = crypto_aead_reqtfm(req);
 467	u8 *auth_tag = pctx->auth_tag;
 468	u8 *iauth_tag = pctx->iauth_tag;
 469	unsigned int authsize = crypto_aead_authsize(aead);
 470	unsigned int cryptlen = req->cryptlen - authsize;
 471
 472	crypto_xor(auth_tag, iauth_tag, 16);
 473	scatterwalk_map_and_copy(iauth_tag, req->src,
 474				 req->assoclen + cryptlen, authsize, 0);
 475	return crypto_memneq(iauth_tag, auth_tag, authsize) ? -EBADMSG : 0;
 476}
 477
 478static void gcm_decrypt_done(void *data, int err)
 479{
 480	struct aead_request *req = data;
 481
 482	if (!err)
 483		err = crypto_gcm_verify(req);
 484
 485	aead_request_complete(req, err);
 486}
 487
 488static int gcm_dec_hash_continue(struct aead_request *req, u32 flags)
 489{
 490	struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
 491	struct skcipher_request *skreq = &pctx->u.skreq;
 492	struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx;
 493
 494	crypto_gcm_init_crypt(req, gctx->cryptlen);
 495	skcipher_request_set_callback(skreq, flags, gcm_decrypt_done, req);
 496	return crypto_skcipher_decrypt(skreq) ?: crypto_gcm_verify(req);
 497}
 498
 499static int crypto_gcm_decrypt(struct aead_request *req)
 500{
 501	struct crypto_aead *aead = crypto_aead_reqtfm(req);
 502	struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
 503	struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx;
 504	unsigned int authsize = crypto_aead_authsize(aead);
 505	unsigned int cryptlen = req->cryptlen;
 506	u32 flags = aead_request_flags(req);
 507
 508	cryptlen -= authsize;
 509
 510	crypto_gcm_init_common(req);
 511
 512	gctx->src = sg_next(pctx->src);
 513	gctx->cryptlen = cryptlen;
 514	gctx->complete = gcm_dec_hash_continue;
 515
 516	return gcm_hash(req, flags);
 517}
 518
 519static int crypto_gcm_init_tfm(struct crypto_aead *tfm)
 520{
 521	struct aead_instance *inst = aead_alg_instance(tfm);
 522	struct gcm_instance_ctx *ictx = aead_instance_ctx(inst);
 523	struct crypto_gcm_ctx *ctx = crypto_aead_ctx(tfm);
 524	struct crypto_skcipher *ctr;
 525	struct crypto_ahash *ghash;
 526	unsigned long align;
 527	int err;
 528
 529	ghash = crypto_spawn_ahash(&ictx->ghash);
 530	if (IS_ERR(ghash))
 531		return PTR_ERR(ghash);
 532
 533	ctr = crypto_spawn_skcipher(&ictx->ctr);
 534	err = PTR_ERR(ctr);
 535	if (IS_ERR(ctr))
 536		goto err_free_hash;
 537
 538	ctx->ctr = ctr;
 539	ctx->ghash = ghash;
 540
 541	align = crypto_aead_alignmask(tfm);
 542	align &= ~(crypto_tfm_ctx_alignment() - 1);
 543	crypto_aead_set_reqsize(tfm,
 544		align + offsetof(struct crypto_gcm_req_priv_ctx, u) +
 545		max(sizeof(struct skcipher_request) +
 546		    crypto_skcipher_reqsize(ctr),
 547		    sizeof(struct ahash_request) +
 548		    crypto_ahash_reqsize(ghash)));
 549
 550	return 0;
 551
 552err_free_hash:
 553	crypto_free_ahash(ghash);
 554	return err;
 555}
 556
 557static void crypto_gcm_exit_tfm(struct crypto_aead *tfm)
 558{
 559	struct crypto_gcm_ctx *ctx = crypto_aead_ctx(tfm);
 560
 561	crypto_free_ahash(ctx->ghash);
 562	crypto_free_skcipher(ctx->ctr);
 563}
 564
 565static void crypto_gcm_free(struct aead_instance *inst)
 566{
 567	struct gcm_instance_ctx *ctx = aead_instance_ctx(inst);
 568
 569	crypto_drop_skcipher(&ctx->ctr);
 570	crypto_drop_ahash(&ctx->ghash);
 571	kfree(inst);
 572}
 573
 574static int crypto_gcm_create_common(struct crypto_template *tmpl,
 575				    struct rtattr **tb,
 576				    const char *ctr_name,
 577				    const char *ghash_name)
 578{
 579	struct skcipher_alg_common *ctr;
 580	u32 mask;
 581	struct aead_instance *inst;
 582	struct gcm_instance_ctx *ctx;
 
 583	struct hash_alg_common *ghash;
 584	int err;
 585
 586	err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_AEAD, &mask);
 587	if (err)
 588		return err;
 589
 590	inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
 591	if (!inst)
 592		return -ENOMEM;
 593	ctx = aead_instance_ctx(inst);
 594
 595	err = crypto_grab_ahash(&ctx->ghash, aead_crypto_instance(inst),
 596				ghash_name, 0, mask);
 597	if (err)
 598		goto err_free_inst;
 599	ghash = crypto_spawn_ahash_alg(&ctx->ghash);
 600
 601	err = -EINVAL;
 602	if (strcmp(ghash->base.cra_name, "ghash") != 0 ||
 603	    ghash->digestsize != 16)
 604		goto err_free_inst;
 605
 606	err = crypto_grab_skcipher(&ctx->ctr, aead_crypto_instance(inst),
 607				   ctr_name, 0, mask);
 608	if (err)
 609		goto err_free_inst;
 610	ctr = crypto_spawn_skcipher_alg_common(&ctx->ctr);
 611
 612	/* The skcipher algorithm must be CTR mode, using 16-byte blocks. */
 613	err = -EINVAL;
 614	if (strncmp(ctr->base.cra_name, "ctr(", 4) != 0 ||
 615	    ctr->ivsize != 16 || ctr->base.cra_blocksize != 1)
 
 616		goto err_free_inst;
 617
 618	err = -ENAMETOOLONG;
 619	if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
 620		     "gcm(%s", ctr->base.cra_name + 4) >= CRYPTO_MAX_ALG_NAME)
 621		goto err_free_inst;
 622
 623	if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
 624		     "gcm_base(%s,%s)", ctr->base.cra_driver_name,
 625		     ghash->base.cra_driver_name) >=
 626	    CRYPTO_MAX_ALG_NAME)
 627		goto err_free_inst;
 628
 629	inst->alg.base.cra_priority = (ghash->base.cra_priority +
 630				       ctr->base.cra_priority) / 2;
 631	inst->alg.base.cra_blocksize = 1;
 632	inst->alg.base.cra_alignmask = ctr->base.cra_alignmask;
 
 633	inst->alg.base.cra_ctxsize = sizeof(struct crypto_gcm_ctx);
 634	inst->alg.ivsize = GCM_AES_IV_SIZE;
 635	inst->alg.chunksize = ctr->chunksize;
 636	inst->alg.maxauthsize = 16;
 637	inst->alg.init = crypto_gcm_init_tfm;
 638	inst->alg.exit = crypto_gcm_exit_tfm;
 639	inst->alg.setkey = crypto_gcm_setkey;
 640	inst->alg.setauthsize = crypto_gcm_setauthsize;
 641	inst->alg.encrypt = crypto_gcm_encrypt;
 642	inst->alg.decrypt = crypto_gcm_decrypt;
 643
 644	inst->free = crypto_gcm_free;
 645
 646	err = aead_register_instance(tmpl, inst);
 647	if (err) {
 648err_free_inst:
 649		crypto_gcm_free(inst);
 650	}
 651	return err;
 652}
 653
 654static int crypto_gcm_create(struct crypto_template *tmpl, struct rtattr **tb)
 655{
 656	const char *cipher_name;
 657	char ctr_name[CRYPTO_MAX_ALG_NAME];
 658
 659	cipher_name = crypto_attr_alg_name(tb[1]);
 660	if (IS_ERR(cipher_name))
 661		return PTR_ERR(cipher_name);
 662
 663	if (snprintf(ctr_name, CRYPTO_MAX_ALG_NAME, "ctr(%s)", cipher_name) >=
 664	    CRYPTO_MAX_ALG_NAME)
 665		return -ENAMETOOLONG;
 666
 667	return crypto_gcm_create_common(tmpl, tb, ctr_name, "ghash");
 668}
 669
 670static int crypto_gcm_base_create(struct crypto_template *tmpl,
 671				  struct rtattr **tb)
 672{
 673	const char *ctr_name;
 674	const char *ghash_name;
 675
 676	ctr_name = crypto_attr_alg_name(tb[1]);
 677	if (IS_ERR(ctr_name))
 678		return PTR_ERR(ctr_name);
 679
 680	ghash_name = crypto_attr_alg_name(tb[2]);
 681	if (IS_ERR(ghash_name))
 682		return PTR_ERR(ghash_name);
 683
 684	return crypto_gcm_create_common(tmpl, tb, ctr_name, ghash_name);
 685}
 686
 687static int crypto_rfc4106_setkey(struct crypto_aead *parent, const u8 *key,
 688				 unsigned int keylen)
 689{
 690	struct crypto_rfc4106_ctx *ctx = crypto_aead_ctx(parent);
 691	struct crypto_aead *child = ctx->child;
 692
 693	if (keylen < 4)
 694		return -EINVAL;
 695
 696	keylen -= 4;
 697	memcpy(ctx->nonce, key + keylen, 4);
 698
 699	crypto_aead_clear_flags(child, CRYPTO_TFM_REQ_MASK);
 700	crypto_aead_set_flags(child, crypto_aead_get_flags(parent) &
 701				     CRYPTO_TFM_REQ_MASK);
 702	return crypto_aead_setkey(child, key, keylen);
 703}
 704
 705static int crypto_rfc4106_setauthsize(struct crypto_aead *parent,
 706				      unsigned int authsize)
 707{
 708	struct crypto_rfc4106_ctx *ctx = crypto_aead_ctx(parent);
 709	int err;
 710
 711	err = crypto_rfc4106_check_authsize(authsize);
 712	if (err)
 713		return err;
 714
 715	return crypto_aead_setauthsize(ctx->child, authsize);
 716}
 717
 718static struct aead_request *crypto_rfc4106_crypt(struct aead_request *req)
 719{
 720	struct crypto_rfc4106_req_ctx *rctx = aead_request_ctx(req);
 721	struct crypto_aead *aead = crypto_aead_reqtfm(req);
 722	struct crypto_rfc4106_ctx *ctx = crypto_aead_ctx(aead);
 723	struct aead_request *subreq = &rctx->subreq;
 724	struct crypto_aead *child = ctx->child;
 725	struct scatterlist *sg;
 726	u8 *iv = PTR_ALIGN((u8 *)(subreq + 1) + crypto_aead_reqsize(child),
 727			   crypto_aead_alignmask(child) + 1);
 728
 729	scatterwalk_map_and_copy(iv + GCM_AES_IV_SIZE, req->src, 0, req->assoclen - 8, 0);
 730
 731	memcpy(iv, ctx->nonce, 4);
 732	memcpy(iv + 4, req->iv, 8);
 733
 734	sg_init_table(rctx->src, 3);
 735	sg_set_buf(rctx->src, iv + GCM_AES_IV_SIZE, req->assoclen - 8);
 736	sg = scatterwalk_ffwd(rctx->src + 1, req->src, req->assoclen);
 737	if (sg != rctx->src + 1)
 738		sg_chain(rctx->src, 2, sg);
 739
 740	if (req->src != req->dst) {
 741		sg_init_table(rctx->dst, 3);
 742		sg_set_buf(rctx->dst, iv + GCM_AES_IV_SIZE, req->assoclen - 8);
 743		sg = scatterwalk_ffwd(rctx->dst + 1, req->dst, req->assoclen);
 744		if (sg != rctx->dst + 1)
 745			sg_chain(rctx->dst, 2, sg);
 746	}
 747
 748	aead_request_set_tfm(subreq, child);
 749	aead_request_set_callback(subreq, req->base.flags, req->base.complete,
 750				  req->base.data);
 751	aead_request_set_crypt(subreq, rctx->src,
 752			       req->src == req->dst ? rctx->src : rctx->dst,
 753			       req->cryptlen, iv);
 754	aead_request_set_ad(subreq, req->assoclen - 8);
 755
 756	return subreq;
 757}
 758
 759static int crypto_rfc4106_encrypt(struct aead_request *req)
 760{
 761	int err;
 762
 763	err = crypto_ipsec_check_assoclen(req->assoclen);
 764	if (err)
 765		return err;
 766
 767	req = crypto_rfc4106_crypt(req);
 768
 769	return crypto_aead_encrypt(req);
 770}
 771
 772static int crypto_rfc4106_decrypt(struct aead_request *req)
 773{
 774	int err;
 775
 776	err = crypto_ipsec_check_assoclen(req->assoclen);
 777	if (err)
 778		return err;
 779
 780	req = crypto_rfc4106_crypt(req);
 781
 782	return crypto_aead_decrypt(req);
 783}
 784
 785static int crypto_rfc4106_init_tfm(struct crypto_aead *tfm)
 786{
 787	struct aead_instance *inst = aead_alg_instance(tfm);
 788	struct crypto_aead_spawn *spawn = aead_instance_ctx(inst);
 789	struct crypto_rfc4106_ctx *ctx = crypto_aead_ctx(tfm);
 790	struct crypto_aead *aead;
 791	unsigned long align;
 792
 793	aead = crypto_spawn_aead(spawn);
 794	if (IS_ERR(aead))
 795		return PTR_ERR(aead);
 796
 797	ctx->child = aead;
 798
 799	align = crypto_aead_alignmask(aead);
 800	align &= ~(crypto_tfm_ctx_alignment() - 1);
 801	crypto_aead_set_reqsize(
 802		tfm,
 803		sizeof(struct crypto_rfc4106_req_ctx) +
 804		ALIGN(crypto_aead_reqsize(aead), crypto_tfm_ctx_alignment()) +
 805		align + 24);
 806
 807	return 0;
 808}
 809
 810static void crypto_rfc4106_exit_tfm(struct crypto_aead *tfm)
 811{
 812	struct crypto_rfc4106_ctx *ctx = crypto_aead_ctx(tfm);
 813
 814	crypto_free_aead(ctx->child);
 815}
 816
 817static void crypto_rfc4106_free(struct aead_instance *inst)
 818{
 819	crypto_drop_aead(aead_instance_ctx(inst));
 820	kfree(inst);
 821}
 822
 823static int crypto_rfc4106_create(struct crypto_template *tmpl,
 824				 struct rtattr **tb)
 825{
 826	u32 mask;
 827	struct aead_instance *inst;
 828	struct crypto_aead_spawn *spawn;
 829	struct aead_alg *alg;
 830	int err;
 831
 832	err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_AEAD, &mask);
 833	if (err)
 834		return err;
 835
 836	inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
 837	if (!inst)
 838		return -ENOMEM;
 839
 840	spawn = aead_instance_ctx(inst);
 841	err = crypto_grab_aead(spawn, aead_crypto_instance(inst),
 842			       crypto_attr_alg_name(tb[1]), 0, mask);
 843	if (err)
 844		goto err_free_inst;
 845
 846	alg = crypto_spawn_aead_alg(spawn);
 847
 848	err = -EINVAL;
 849
 850	/* Underlying IV size must be 12. */
 851	if (crypto_aead_alg_ivsize(alg) != GCM_AES_IV_SIZE)
 852		goto err_free_inst;
 853
 854	/* Not a stream cipher? */
 855	if (alg->base.cra_blocksize != 1)
 856		goto err_free_inst;
 857
 858	err = -ENAMETOOLONG;
 859	if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
 860		     "rfc4106(%s)", alg->base.cra_name) >=
 861	    CRYPTO_MAX_ALG_NAME ||
 862	    snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
 863		     "rfc4106(%s)", alg->base.cra_driver_name) >=
 864	    CRYPTO_MAX_ALG_NAME)
 865		goto err_free_inst;
 866
 867	inst->alg.base.cra_priority = alg->base.cra_priority;
 868	inst->alg.base.cra_blocksize = 1;
 869	inst->alg.base.cra_alignmask = alg->base.cra_alignmask;
 870
 871	inst->alg.base.cra_ctxsize = sizeof(struct crypto_rfc4106_ctx);
 872
 873	inst->alg.ivsize = GCM_RFC4106_IV_SIZE;
 874	inst->alg.chunksize = crypto_aead_alg_chunksize(alg);
 875	inst->alg.maxauthsize = crypto_aead_alg_maxauthsize(alg);
 876
 877	inst->alg.init = crypto_rfc4106_init_tfm;
 878	inst->alg.exit = crypto_rfc4106_exit_tfm;
 879
 880	inst->alg.setkey = crypto_rfc4106_setkey;
 881	inst->alg.setauthsize = crypto_rfc4106_setauthsize;
 882	inst->alg.encrypt = crypto_rfc4106_encrypt;
 883	inst->alg.decrypt = crypto_rfc4106_decrypt;
 884
 885	inst->free = crypto_rfc4106_free;
 886
 887	err = aead_register_instance(tmpl, inst);
 888	if (err) {
 889err_free_inst:
 890		crypto_rfc4106_free(inst);
 891	}
 892	return err;
 893}
 894
 895static int crypto_rfc4543_setkey(struct crypto_aead *parent, const u8 *key,
 896				 unsigned int keylen)
 897{
 898	struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(parent);
 899	struct crypto_aead *child = ctx->child;
 900
 901	if (keylen < 4)
 902		return -EINVAL;
 903
 904	keylen -= 4;
 905	memcpy(ctx->nonce, key + keylen, 4);
 906
 907	crypto_aead_clear_flags(child, CRYPTO_TFM_REQ_MASK);
 908	crypto_aead_set_flags(child, crypto_aead_get_flags(parent) &
 909				     CRYPTO_TFM_REQ_MASK);
 910	return crypto_aead_setkey(child, key, keylen);
 911}
 912
 913static int crypto_rfc4543_setauthsize(struct crypto_aead *parent,
 914				      unsigned int authsize)
 915{
 916	struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(parent);
 917
 918	if (authsize != 16)
 919		return -EINVAL;
 920
 921	return crypto_aead_setauthsize(ctx->child, authsize);
 922}
 923
 924static int crypto_rfc4543_crypt(struct aead_request *req, bool enc)
 925{
 926	struct crypto_aead *aead = crypto_aead_reqtfm(req);
 927	struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(aead);
 928	struct crypto_rfc4543_req_ctx *rctx = aead_request_ctx(req);
 929	struct aead_request *subreq = &rctx->subreq;
 930	unsigned int authsize = crypto_aead_authsize(aead);
 931	u8 *iv = PTR_ALIGN((u8 *)(rctx + 1) + crypto_aead_reqsize(ctx->child),
 932			   crypto_aead_alignmask(ctx->child) + 1);
 933	int err;
 934
 935	if (req->src != req->dst) {
 936		err = crypto_rfc4543_copy_src_to_dst(req, enc);
 937		if (err)
 938			return err;
 939	}
 940
 941	memcpy(iv, ctx->nonce, 4);
 942	memcpy(iv + 4, req->iv, 8);
 943
 944	aead_request_set_tfm(subreq, ctx->child);
 945	aead_request_set_callback(subreq, req->base.flags,
 946				  req->base.complete, req->base.data);
 947	aead_request_set_crypt(subreq, req->src, req->dst,
 948			       enc ? 0 : authsize, iv);
 949	aead_request_set_ad(subreq, req->assoclen + req->cryptlen -
 950				    subreq->cryptlen);
 951
 952	return enc ? crypto_aead_encrypt(subreq) : crypto_aead_decrypt(subreq);
 953}
 954
 955static int crypto_rfc4543_copy_src_to_dst(struct aead_request *req, bool enc)
 956{
 957	struct crypto_aead *aead = crypto_aead_reqtfm(req);
 958	struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(aead);
 959	unsigned int authsize = crypto_aead_authsize(aead);
 960	unsigned int nbytes = req->assoclen + req->cryptlen -
 961			      (enc ? 0 : authsize);
 962	SYNC_SKCIPHER_REQUEST_ON_STACK(nreq, ctx->null);
 963
 964	skcipher_request_set_sync_tfm(nreq, ctx->null);
 965	skcipher_request_set_callback(nreq, req->base.flags, NULL, NULL);
 966	skcipher_request_set_crypt(nreq, req->src, req->dst, nbytes, NULL);
 967
 968	return crypto_skcipher_encrypt(nreq);
 969}
 970
 971static int crypto_rfc4543_encrypt(struct aead_request *req)
 972{
 973	return crypto_ipsec_check_assoclen(req->assoclen) ?:
 974	       crypto_rfc4543_crypt(req, true);
 975}
 976
 977static int crypto_rfc4543_decrypt(struct aead_request *req)
 978{
 979	return crypto_ipsec_check_assoclen(req->assoclen) ?:
 980	       crypto_rfc4543_crypt(req, false);
 981}
 982
 983static int crypto_rfc4543_init_tfm(struct crypto_aead *tfm)
 984{
 985	struct aead_instance *inst = aead_alg_instance(tfm);
 986	struct crypto_rfc4543_instance_ctx *ictx = aead_instance_ctx(inst);
 987	struct crypto_aead_spawn *spawn = &ictx->aead;
 988	struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(tfm);
 989	struct crypto_aead *aead;
 990	struct crypto_sync_skcipher *null;
 991	unsigned long align;
 992	int err = 0;
 993
 994	aead = crypto_spawn_aead(spawn);
 995	if (IS_ERR(aead))
 996		return PTR_ERR(aead);
 997
 998	null = crypto_get_default_null_skcipher();
 999	err = PTR_ERR(null);
1000	if (IS_ERR(null))
1001		goto err_free_aead;
1002
1003	ctx->child = aead;
1004	ctx->null = null;
1005
1006	align = crypto_aead_alignmask(aead);
1007	align &= ~(crypto_tfm_ctx_alignment() - 1);
1008	crypto_aead_set_reqsize(
1009		tfm,
1010		sizeof(struct crypto_rfc4543_req_ctx) +
1011		ALIGN(crypto_aead_reqsize(aead), crypto_tfm_ctx_alignment()) +
1012		align + GCM_AES_IV_SIZE);
1013
1014	return 0;
1015
1016err_free_aead:
1017	crypto_free_aead(aead);
1018	return err;
1019}
1020
1021static void crypto_rfc4543_exit_tfm(struct crypto_aead *tfm)
1022{
1023	struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(tfm);
1024
1025	crypto_free_aead(ctx->child);
1026	crypto_put_default_null_skcipher();
1027}
1028
1029static void crypto_rfc4543_free(struct aead_instance *inst)
1030{
1031	struct crypto_rfc4543_instance_ctx *ctx = aead_instance_ctx(inst);
1032
1033	crypto_drop_aead(&ctx->aead);
1034
1035	kfree(inst);
1036}
1037
1038static int crypto_rfc4543_create(struct crypto_template *tmpl,
1039				struct rtattr **tb)
1040{
1041	u32 mask;
1042	struct aead_instance *inst;
1043	struct aead_alg *alg;
1044	struct crypto_rfc4543_instance_ctx *ctx;
1045	int err;
1046
1047	err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_AEAD, &mask);
1048	if (err)
1049		return err;
1050
1051	inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
1052	if (!inst)
1053		return -ENOMEM;
1054
1055	ctx = aead_instance_ctx(inst);
1056	err = crypto_grab_aead(&ctx->aead, aead_crypto_instance(inst),
1057			       crypto_attr_alg_name(tb[1]), 0, mask);
1058	if (err)
1059		goto err_free_inst;
1060
1061	alg = crypto_spawn_aead_alg(&ctx->aead);
1062
1063	err = -EINVAL;
1064
1065	/* Underlying IV size must be 12. */
1066	if (crypto_aead_alg_ivsize(alg) != GCM_AES_IV_SIZE)
1067		goto err_free_inst;
1068
1069	/* Not a stream cipher? */
1070	if (alg->base.cra_blocksize != 1)
1071		goto err_free_inst;
1072
1073	err = -ENAMETOOLONG;
1074	if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
1075		     "rfc4543(%s)", alg->base.cra_name) >=
1076	    CRYPTO_MAX_ALG_NAME ||
1077	    snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
1078		     "rfc4543(%s)", alg->base.cra_driver_name) >=
1079	    CRYPTO_MAX_ALG_NAME)
1080		goto err_free_inst;
1081
1082	inst->alg.base.cra_priority = alg->base.cra_priority;
1083	inst->alg.base.cra_blocksize = 1;
1084	inst->alg.base.cra_alignmask = alg->base.cra_alignmask;
1085
1086	inst->alg.base.cra_ctxsize = sizeof(struct crypto_rfc4543_ctx);
1087
1088	inst->alg.ivsize = GCM_RFC4543_IV_SIZE;
1089	inst->alg.chunksize = crypto_aead_alg_chunksize(alg);
1090	inst->alg.maxauthsize = crypto_aead_alg_maxauthsize(alg);
1091
1092	inst->alg.init = crypto_rfc4543_init_tfm;
1093	inst->alg.exit = crypto_rfc4543_exit_tfm;
1094
1095	inst->alg.setkey = crypto_rfc4543_setkey;
1096	inst->alg.setauthsize = crypto_rfc4543_setauthsize;
1097	inst->alg.encrypt = crypto_rfc4543_encrypt;
1098	inst->alg.decrypt = crypto_rfc4543_decrypt;
1099
1100	inst->free = crypto_rfc4543_free;
1101
1102	err = aead_register_instance(tmpl, inst);
1103	if (err) {
1104err_free_inst:
1105		crypto_rfc4543_free(inst);
1106	}
1107	return err;
1108}
1109
1110static struct crypto_template crypto_gcm_tmpls[] = {
1111	{
1112		.name = "gcm_base",
1113		.create = crypto_gcm_base_create,
1114		.module = THIS_MODULE,
1115	}, {
1116		.name = "gcm",
1117		.create = crypto_gcm_create,
1118		.module = THIS_MODULE,
1119	}, {
1120		.name = "rfc4106",
1121		.create = crypto_rfc4106_create,
1122		.module = THIS_MODULE,
1123	}, {
1124		.name = "rfc4543",
1125		.create = crypto_rfc4543_create,
1126		.module = THIS_MODULE,
1127	},
1128};
1129
1130static int __init crypto_gcm_module_init(void)
1131{
1132	int err;
1133
1134	gcm_zeroes = kzalloc(sizeof(*gcm_zeroes), GFP_KERNEL);
1135	if (!gcm_zeroes)
1136		return -ENOMEM;
1137
1138	sg_init_one(&gcm_zeroes->sg, gcm_zeroes->buf, sizeof(gcm_zeroes->buf));
1139
1140	err = crypto_register_templates(crypto_gcm_tmpls,
1141					ARRAY_SIZE(crypto_gcm_tmpls));
1142	if (err)
1143		kfree(gcm_zeroes);
1144
1145	return err;
1146}
1147
1148static void __exit crypto_gcm_module_exit(void)
1149{
1150	kfree(gcm_zeroes);
1151	crypto_unregister_templates(crypto_gcm_tmpls,
1152				    ARRAY_SIZE(crypto_gcm_tmpls));
1153}
1154
1155subsys_initcall(crypto_gcm_module_init);
1156module_exit(crypto_gcm_module_exit);
1157
1158MODULE_LICENSE("GPL");
1159MODULE_DESCRIPTION("Galois/Counter Mode");
1160MODULE_AUTHOR("Mikko Herranen <mh1@iki.fi>");
1161MODULE_ALIAS_CRYPTO("gcm_base");
1162MODULE_ALIAS_CRYPTO("rfc4106");
1163MODULE_ALIAS_CRYPTO("rfc4543");
1164MODULE_ALIAS_CRYPTO("gcm");
   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/null.h>
  13#include <crypto/scatterwalk.h>
  14#include <crypto/gcm.h>
  15#include <crypto/hash.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
  22struct gcm_instance_ctx {
  23	struct crypto_skcipher_spawn ctr;
  24	struct crypto_ahash_spawn ghash;
  25};
  26
  27struct crypto_gcm_ctx {
  28	struct crypto_skcipher *ctr;
  29	struct crypto_ahash *ghash;
  30};
  31
  32struct crypto_rfc4106_ctx {
  33	struct crypto_aead *child;
  34	u8 nonce[4];
  35};
  36
  37struct crypto_rfc4106_req_ctx {
  38	struct scatterlist src[3];
  39	struct scatterlist dst[3];
  40	struct aead_request subreq;
  41};
  42
  43struct crypto_rfc4543_instance_ctx {
  44	struct crypto_aead_spawn aead;
  45};
  46
  47struct crypto_rfc4543_ctx {
  48	struct crypto_aead *child;
  49	struct crypto_sync_skcipher *null;
  50	u8 nonce[4];
  51};
  52
  53struct crypto_rfc4543_req_ctx {
  54	struct aead_request subreq;
  55};
  56
  57struct crypto_gcm_ghash_ctx {
  58	unsigned int cryptlen;
  59	struct scatterlist *src;
  60	int (*complete)(struct aead_request *req, u32 flags);
  61};
  62
  63struct crypto_gcm_req_priv_ctx {
  64	u8 iv[16];
  65	u8 auth_tag[16];
  66	u8 iauth_tag[16];
  67	struct scatterlist src[3];
  68	struct scatterlist dst[3];
  69	struct scatterlist sg;
  70	struct crypto_gcm_ghash_ctx ghash_ctx;
  71	union {
  72		struct ahash_request ahreq;
  73		struct skcipher_request skreq;
  74	} u;
  75};
  76
  77static struct {
  78	u8 buf[16];
  79	struct scatterlist sg;
  80} *gcm_zeroes;
  81
  82static int crypto_rfc4543_copy_src_to_dst(struct aead_request *req, bool enc);
  83
  84static inline struct crypto_gcm_req_priv_ctx *crypto_gcm_reqctx(
  85	struct aead_request *req)
  86{
  87	unsigned long align = crypto_aead_alignmask(crypto_aead_reqtfm(req));
  88
  89	return (void *)PTR_ALIGN((u8 *)aead_request_ctx(req), align + 1);
  90}
  91
  92static int crypto_gcm_setkey(struct crypto_aead *aead, const u8 *key,
  93			     unsigned int keylen)
  94{
  95	struct crypto_gcm_ctx *ctx = crypto_aead_ctx(aead);
  96	struct crypto_ahash *ghash = ctx->ghash;
  97	struct crypto_skcipher *ctr = ctx->ctr;
  98	struct {
  99		be128 hash;
 100		u8 iv[16];
 101
 102		struct crypto_wait wait;
 103
 104		struct scatterlist sg[1];
 105		struct skcipher_request req;
 106	} *data;
 107	int err;
 108
 109	crypto_skcipher_clear_flags(ctr, CRYPTO_TFM_REQ_MASK);
 110	crypto_skcipher_set_flags(ctr, crypto_aead_get_flags(aead) &
 111				       CRYPTO_TFM_REQ_MASK);
 112	err = crypto_skcipher_setkey(ctr, key, keylen);
 113	if (err)
 114		return err;
 115
 116	data = kzalloc(sizeof(*data) + crypto_skcipher_reqsize(ctr),
 117		       GFP_KERNEL);
 118	if (!data)
 119		return -ENOMEM;
 120
 121	crypto_init_wait(&data->wait);
 122	sg_init_one(data->sg, &data->hash, sizeof(data->hash));
 123	skcipher_request_set_tfm(&data->req, ctr);
 124	skcipher_request_set_callback(&data->req, CRYPTO_TFM_REQ_MAY_SLEEP |
 125						  CRYPTO_TFM_REQ_MAY_BACKLOG,
 126				      crypto_req_done,
 127				      &data->wait);
 128	skcipher_request_set_crypt(&data->req, data->sg, data->sg,
 129				   sizeof(data->hash), data->iv);
 130
 131	err = crypto_wait_req(crypto_skcipher_encrypt(&data->req),
 132							&data->wait);
 133
 134	if (err)
 135		goto out;
 136
 137	crypto_ahash_clear_flags(ghash, CRYPTO_TFM_REQ_MASK);
 138	crypto_ahash_set_flags(ghash, crypto_aead_get_flags(aead) &
 139			       CRYPTO_TFM_REQ_MASK);
 140	err = crypto_ahash_setkey(ghash, (u8 *)&data->hash, sizeof(be128));
 141out:
 142	kfree_sensitive(data);
 143	return err;
 144}
 145
 146static int crypto_gcm_setauthsize(struct crypto_aead *tfm,
 147				  unsigned int authsize)
 148{
 149	return crypto_gcm_check_authsize(authsize);
 150}
 151
 152static void crypto_gcm_init_common(struct aead_request *req)
 153{
 154	struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
 155	__be32 counter = cpu_to_be32(1);
 156	struct scatterlist *sg;
 157
 158	memset(pctx->auth_tag, 0, sizeof(pctx->auth_tag));
 159	memcpy(pctx->iv, req->iv, GCM_AES_IV_SIZE);
 160	memcpy(pctx->iv + GCM_AES_IV_SIZE, &counter, 4);
 161
 162	sg_init_table(pctx->src, 3);
 163	sg_set_buf(pctx->src, pctx->auth_tag, sizeof(pctx->auth_tag));
 164	sg = scatterwalk_ffwd(pctx->src + 1, req->src, req->assoclen);
 165	if (sg != pctx->src + 1)
 166		sg_chain(pctx->src, 2, sg);
 167
 168	if (req->src != req->dst) {
 169		sg_init_table(pctx->dst, 3);
 170		sg_set_buf(pctx->dst, pctx->auth_tag, sizeof(pctx->auth_tag));
 171		sg = scatterwalk_ffwd(pctx->dst + 1, req->dst, req->assoclen);
 172		if (sg != pctx->dst + 1)
 173			sg_chain(pctx->dst, 2, sg);
 174	}
 175}
 176
 177static void crypto_gcm_init_crypt(struct aead_request *req,
 178				  unsigned int cryptlen)
 179{
 180	struct crypto_aead *aead = crypto_aead_reqtfm(req);
 181	struct crypto_gcm_ctx *ctx = crypto_aead_ctx(aead);
 182	struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
 183	struct skcipher_request *skreq = &pctx->u.skreq;
 184	struct scatterlist *dst;
 185
 186	dst = req->src == req->dst ? pctx->src : pctx->dst;
 187
 188	skcipher_request_set_tfm(skreq, ctx->ctr);
 189	skcipher_request_set_crypt(skreq, pctx->src, dst,
 190				     cryptlen + sizeof(pctx->auth_tag),
 191				     pctx->iv);
 192}
 193
 194static inline unsigned int gcm_remain(unsigned int len)
 195{
 196	len &= 0xfU;
 197	return len ? 16 - len : 0;
 198}
 199
 200static void gcm_hash_len_done(struct crypto_async_request *areq, int err);
 201
 202static int gcm_hash_update(struct aead_request *req,
 203			   crypto_completion_t compl,
 204			   struct scatterlist *src,
 205			   unsigned int len, u32 flags)
 206{
 207	struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
 208	struct ahash_request *ahreq = &pctx->u.ahreq;
 209
 210	ahash_request_set_callback(ahreq, flags, compl, req);
 211	ahash_request_set_crypt(ahreq, src, NULL, len);
 212
 213	return crypto_ahash_update(ahreq);
 214}
 215
 216static int gcm_hash_remain(struct aead_request *req,
 217			   unsigned int remain,
 218			   crypto_completion_t compl, u32 flags)
 219{
 220	return gcm_hash_update(req, compl, &gcm_zeroes->sg, remain, flags);
 221}
 222
 223static int gcm_hash_len(struct aead_request *req, u32 flags)
 224{
 225	struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
 226	struct ahash_request *ahreq = &pctx->u.ahreq;
 227	struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx;
 228	be128 lengths;
 229
 230	lengths.a = cpu_to_be64(req->assoclen * 8);
 231	lengths.b = cpu_to_be64(gctx->cryptlen * 8);
 232	memcpy(pctx->iauth_tag, &lengths, 16);
 233	sg_init_one(&pctx->sg, pctx->iauth_tag, 16);
 234	ahash_request_set_callback(ahreq, flags, gcm_hash_len_done, req);
 235	ahash_request_set_crypt(ahreq, &pctx->sg,
 236				pctx->iauth_tag, sizeof(lengths));
 237
 238	return crypto_ahash_finup(ahreq);
 239}
 240
 241static int gcm_hash_len_continue(struct aead_request *req, u32 flags)
 242{
 243	struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
 244	struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx;
 245
 246	return gctx->complete(req, flags);
 247}
 248
 249static void gcm_hash_len_done(struct crypto_async_request *areq, int err)
 250{
 251	struct aead_request *req = areq->data;
 252
 253	if (err)
 254		goto out;
 255
 256	err = gcm_hash_len_continue(req, 0);
 257	if (err == -EINPROGRESS)
 258		return;
 259
 260out:
 261	aead_request_complete(req, err);
 262}
 263
 264static int gcm_hash_crypt_remain_continue(struct aead_request *req, u32 flags)
 265{
 266	return gcm_hash_len(req, flags) ?:
 267	       gcm_hash_len_continue(req, flags);
 268}
 269
 270static void gcm_hash_crypt_remain_done(struct crypto_async_request *areq,
 271				       int err)
 272{
 273	struct aead_request *req = areq->data;
 274
 275	if (err)
 276		goto out;
 277
 278	err = gcm_hash_crypt_remain_continue(req, 0);
 279	if (err == -EINPROGRESS)
 280		return;
 281
 282out:
 283	aead_request_complete(req, err);
 284}
 285
 286static int gcm_hash_crypt_continue(struct aead_request *req, u32 flags)
 287{
 288	struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
 289	struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx;
 290	unsigned int remain;
 291
 292	remain = gcm_remain(gctx->cryptlen);
 293	if (remain)
 294		return gcm_hash_remain(req, remain,
 295				       gcm_hash_crypt_remain_done, flags) ?:
 296		       gcm_hash_crypt_remain_continue(req, flags);
 297
 298	return gcm_hash_crypt_remain_continue(req, flags);
 299}
 300
 301static void gcm_hash_crypt_done(struct crypto_async_request *areq, int err)
 302{
 303	struct aead_request *req = areq->data;
 304
 305	if (err)
 306		goto out;
 307
 308	err = gcm_hash_crypt_continue(req, 0);
 309	if (err == -EINPROGRESS)
 310		return;
 311
 312out:
 313	aead_request_complete(req, err);
 314}
 315
 316static int gcm_hash_assoc_remain_continue(struct aead_request *req, u32 flags)
 317{
 318	struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
 319	struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx;
 320
 321	if (gctx->cryptlen)
 322		return gcm_hash_update(req, gcm_hash_crypt_done,
 323				       gctx->src, gctx->cryptlen, flags) ?:
 324		       gcm_hash_crypt_continue(req, flags);
 325
 326	return gcm_hash_crypt_remain_continue(req, flags);
 327}
 328
 329static void gcm_hash_assoc_remain_done(struct crypto_async_request *areq,
 330				       int err)
 331{
 332	struct aead_request *req = areq->data;
 333
 334	if (err)
 335		goto out;
 336
 337	err = gcm_hash_assoc_remain_continue(req, 0);
 338	if (err == -EINPROGRESS)
 339		return;
 340
 341out:
 342	aead_request_complete(req, err);
 343}
 344
 345static int gcm_hash_assoc_continue(struct aead_request *req, u32 flags)
 346{
 347	unsigned int remain;
 348
 349	remain = gcm_remain(req->assoclen);
 350	if (remain)
 351		return gcm_hash_remain(req, remain,
 352				       gcm_hash_assoc_remain_done, flags) ?:
 353		       gcm_hash_assoc_remain_continue(req, flags);
 354
 355	return gcm_hash_assoc_remain_continue(req, flags);
 356}
 357
 358static void gcm_hash_assoc_done(struct crypto_async_request *areq, int err)
 359{
 360	struct aead_request *req = areq->data;
 361
 362	if (err)
 363		goto out;
 364
 365	err = gcm_hash_assoc_continue(req, 0);
 366	if (err == -EINPROGRESS)
 367		return;
 368
 369out:
 370	aead_request_complete(req, err);
 371}
 372
 373static int gcm_hash_init_continue(struct aead_request *req, u32 flags)
 374{
 375	if (req->assoclen)
 376		return gcm_hash_update(req, gcm_hash_assoc_done,
 377				       req->src, req->assoclen, flags) ?:
 378		       gcm_hash_assoc_continue(req, flags);
 379
 380	return gcm_hash_assoc_remain_continue(req, flags);
 381}
 382
 383static void gcm_hash_init_done(struct crypto_async_request *areq, int err)
 384{
 385	struct aead_request *req = areq->data;
 386
 387	if (err)
 388		goto out;
 389
 390	err = gcm_hash_init_continue(req, 0);
 391	if (err == -EINPROGRESS)
 392		return;
 393
 394out:
 395	aead_request_complete(req, err);
 396}
 397
 398static int gcm_hash(struct aead_request *req, u32 flags)
 399{
 400	struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
 401	struct ahash_request *ahreq = &pctx->u.ahreq;
 402	struct crypto_gcm_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
 403
 404	ahash_request_set_tfm(ahreq, ctx->ghash);
 405
 406	ahash_request_set_callback(ahreq, flags, gcm_hash_init_done, req);
 407	return crypto_ahash_init(ahreq) ?:
 408	       gcm_hash_init_continue(req, flags);
 409}
 410
 411static int gcm_enc_copy_hash(struct aead_request *req, u32 flags)
 412{
 413	struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
 414	struct crypto_aead *aead = crypto_aead_reqtfm(req);
 415	u8 *auth_tag = pctx->auth_tag;
 416
 417	crypto_xor(auth_tag, pctx->iauth_tag, 16);
 418	scatterwalk_map_and_copy(auth_tag, req->dst,
 419				 req->assoclen + req->cryptlen,
 420				 crypto_aead_authsize(aead), 1);
 421	return 0;
 422}
 423
 424static int gcm_encrypt_continue(struct aead_request *req, u32 flags)
 425{
 426	struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
 427	struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx;
 428
 429	gctx->src = sg_next(req->src == req->dst ? pctx->src : pctx->dst);
 430	gctx->cryptlen = req->cryptlen;
 431	gctx->complete = gcm_enc_copy_hash;
 432
 433	return gcm_hash(req, flags);
 434}
 435
 436static void gcm_encrypt_done(struct crypto_async_request *areq, int err)
 437{
 438	struct aead_request *req = areq->data;
 439
 440	if (err)
 441		goto out;
 442
 443	err = gcm_encrypt_continue(req, 0);
 444	if (err == -EINPROGRESS)
 445		return;
 446
 447out:
 448	aead_request_complete(req, err);
 449}
 450
 451static int crypto_gcm_encrypt(struct aead_request *req)
 452{
 453	struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
 454	struct skcipher_request *skreq = &pctx->u.skreq;
 455	u32 flags = aead_request_flags(req);
 456
 457	crypto_gcm_init_common(req);
 458	crypto_gcm_init_crypt(req, req->cryptlen);
 459	skcipher_request_set_callback(skreq, flags, gcm_encrypt_done, req);
 460
 461	return crypto_skcipher_encrypt(skreq) ?:
 462	       gcm_encrypt_continue(req, flags);
 463}
 464
 465static int crypto_gcm_verify(struct aead_request *req)
 466{
 467	struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
 468	struct crypto_aead *aead = crypto_aead_reqtfm(req);
 469	u8 *auth_tag = pctx->auth_tag;
 470	u8 *iauth_tag = pctx->iauth_tag;
 471	unsigned int authsize = crypto_aead_authsize(aead);
 472	unsigned int cryptlen = req->cryptlen - authsize;
 473
 474	crypto_xor(auth_tag, iauth_tag, 16);
 475	scatterwalk_map_and_copy(iauth_tag, req->src,
 476				 req->assoclen + cryptlen, authsize, 0);
 477	return crypto_memneq(iauth_tag, auth_tag, authsize) ? -EBADMSG : 0;
 478}
 479
 480static void gcm_decrypt_done(struct crypto_async_request *areq, int err)
 481{
 482	struct aead_request *req = areq->data;
 483
 484	if (!err)
 485		err = crypto_gcm_verify(req);
 486
 487	aead_request_complete(req, err);
 488}
 489
 490static int gcm_dec_hash_continue(struct aead_request *req, u32 flags)
 491{
 492	struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
 493	struct skcipher_request *skreq = &pctx->u.skreq;
 494	struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx;
 495
 496	crypto_gcm_init_crypt(req, gctx->cryptlen);
 497	skcipher_request_set_callback(skreq, flags, gcm_decrypt_done, req);
 498	return crypto_skcipher_decrypt(skreq) ?: crypto_gcm_verify(req);
 499}
 500
 501static int crypto_gcm_decrypt(struct aead_request *req)
 502{
 503	struct crypto_aead *aead = crypto_aead_reqtfm(req);
 504	struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
 505	struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx;
 506	unsigned int authsize = crypto_aead_authsize(aead);
 507	unsigned int cryptlen = req->cryptlen;
 508	u32 flags = aead_request_flags(req);
 509
 510	cryptlen -= authsize;
 511
 512	crypto_gcm_init_common(req);
 513
 514	gctx->src = sg_next(pctx->src);
 515	gctx->cryptlen = cryptlen;
 516	gctx->complete = gcm_dec_hash_continue;
 517
 518	return gcm_hash(req, flags);
 519}
 520
 521static int crypto_gcm_init_tfm(struct crypto_aead *tfm)
 522{
 523	struct aead_instance *inst = aead_alg_instance(tfm);
 524	struct gcm_instance_ctx *ictx = aead_instance_ctx(inst);
 525	struct crypto_gcm_ctx *ctx = crypto_aead_ctx(tfm);
 526	struct crypto_skcipher *ctr;
 527	struct crypto_ahash *ghash;
 528	unsigned long align;
 529	int err;
 530
 531	ghash = crypto_spawn_ahash(&ictx->ghash);
 532	if (IS_ERR(ghash))
 533		return PTR_ERR(ghash);
 534
 535	ctr = crypto_spawn_skcipher(&ictx->ctr);
 536	err = PTR_ERR(ctr);
 537	if (IS_ERR(ctr))
 538		goto err_free_hash;
 539
 540	ctx->ctr = ctr;
 541	ctx->ghash = ghash;
 542
 543	align = crypto_aead_alignmask(tfm);
 544	align &= ~(crypto_tfm_ctx_alignment() - 1);
 545	crypto_aead_set_reqsize(tfm,
 546		align + offsetof(struct crypto_gcm_req_priv_ctx, u) +
 547		max(sizeof(struct skcipher_request) +
 548		    crypto_skcipher_reqsize(ctr),
 549		    sizeof(struct ahash_request) +
 550		    crypto_ahash_reqsize(ghash)));
 551
 552	return 0;
 553
 554err_free_hash:
 555	crypto_free_ahash(ghash);
 556	return err;
 557}
 558
 559static void crypto_gcm_exit_tfm(struct crypto_aead *tfm)
 560{
 561	struct crypto_gcm_ctx *ctx = crypto_aead_ctx(tfm);
 562
 563	crypto_free_ahash(ctx->ghash);
 564	crypto_free_skcipher(ctx->ctr);
 565}
 566
 567static void crypto_gcm_free(struct aead_instance *inst)
 568{
 569	struct gcm_instance_ctx *ctx = aead_instance_ctx(inst);
 570
 571	crypto_drop_skcipher(&ctx->ctr);
 572	crypto_drop_ahash(&ctx->ghash);
 573	kfree(inst);
 574}
 575
 576static int crypto_gcm_create_common(struct crypto_template *tmpl,
 577				    struct rtattr **tb,
 578				    const char *ctr_name,
 579				    const char *ghash_name)
 580{
 
 581	u32 mask;
 582	struct aead_instance *inst;
 583	struct gcm_instance_ctx *ctx;
 584	struct skcipher_alg *ctr;
 585	struct hash_alg_common *ghash;
 586	int err;
 587
 588	err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_AEAD, &mask);
 589	if (err)
 590		return err;
 591
 592	inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
 593	if (!inst)
 594		return -ENOMEM;
 595	ctx = aead_instance_ctx(inst);
 596
 597	err = crypto_grab_ahash(&ctx->ghash, aead_crypto_instance(inst),
 598				ghash_name, 0, mask);
 599	if (err)
 600		goto err_free_inst;
 601	ghash = crypto_spawn_ahash_alg(&ctx->ghash);
 602
 603	err = -EINVAL;
 604	if (strcmp(ghash->base.cra_name, "ghash") != 0 ||
 605	    ghash->digestsize != 16)
 606		goto err_free_inst;
 607
 608	err = crypto_grab_skcipher(&ctx->ctr, aead_crypto_instance(inst),
 609				   ctr_name, 0, mask);
 610	if (err)
 611		goto err_free_inst;
 612	ctr = crypto_spawn_skcipher_alg(&ctx->ctr);
 613
 614	/* The skcipher algorithm must be CTR mode, using 16-byte blocks. */
 615	err = -EINVAL;
 616	if (strncmp(ctr->base.cra_name, "ctr(", 4) != 0 ||
 617	    crypto_skcipher_alg_ivsize(ctr) != 16 ||
 618	    ctr->base.cra_blocksize != 1)
 619		goto err_free_inst;
 620
 621	err = -ENAMETOOLONG;
 622	if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
 623		     "gcm(%s", ctr->base.cra_name + 4) >= CRYPTO_MAX_ALG_NAME)
 624		goto err_free_inst;
 625
 626	if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
 627		     "gcm_base(%s,%s)", ctr->base.cra_driver_name,
 628		     ghash->base.cra_driver_name) >=
 629	    CRYPTO_MAX_ALG_NAME)
 630		goto err_free_inst;
 631
 632	inst->alg.base.cra_priority = (ghash->base.cra_priority +
 633				       ctr->base.cra_priority) / 2;
 634	inst->alg.base.cra_blocksize = 1;
 635	inst->alg.base.cra_alignmask = ghash->base.cra_alignmask |
 636				       ctr->base.cra_alignmask;
 637	inst->alg.base.cra_ctxsize = sizeof(struct crypto_gcm_ctx);
 638	inst->alg.ivsize = GCM_AES_IV_SIZE;
 639	inst->alg.chunksize = crypto_skcipher_alg_chunksize(ctr);
 640	inst->alg.maxauthsize = 16;
 641	inst->alg.init = crypto_gcm_init_tfm;
 642	inst->alg.exit = crypto_gcm_exit_tfm;
 643	inst->alg.setkey = crypto_gcm_setkey;
 644	inst->alg.setauthsize = crypto_gcm_setauthsize;
 645	inst->alg.encrypt = crypto_gcm_encrypt;
 646	inst->alg.decrypt = crypto_gcm_decrypt;
 647
 648	inst->free = crypto_gcm_free;
 649
 650	err = aead_register_instance(tmpl, inst);
 651	if (err) {
 652err_free_inst:
 653		crypto_gcm_free(inst);
 654	}
 655	return err;
 656}
 657
 658static int crypto_gcm_create(struct crypto_template *tmpl, struct rtattr **tb)
 659{
 660	const char *cipher_name;
 661	char ctr_name[CRYPTO_MAX_ALG_NAME];
 662
 663	cipher_name = crypto_attr_alg_name(tb[1]);
 664	if (IS_ERR(cipher_name))
 665		return PTR_ERR(cipher_name);
 666
 667	if (snprintf(ctr_name, CRYPTO_MAX_ALG_NAME, "ctr(%s)", cipher_name) >=
 668	    CRYPTO_MAX_ALG_NAME)
 669		return -ENAMETOOLONG;
 670
 671	return crypto_gcm_create_common(tmpl, tb, ctr_name, "ghash");
 672}
 673
 674static int crypto_gcm_base_create(struct crypto_template *tmpl,
 675				  struct rtattr **tb)
 676{
 677	const char *ctr_name;
 678	const char *ghash_name;
 679
 680	ctr_name = crypto_attr_alg_name(tb[1]);
 681	if (IS_ERR(ctr_name))
 682		return PTR_ERR(ctr_name);
 683
 684	ghash_name = crypto_attr_alg_name(tb[2]);
 685	if (IS_ERR(ghash_name))
 686		return PTR_ERR(ghash_name);
 687
 688	return crypto_gcm_create_common(tmpl, tb, ctr_name, ghash_name);
 689}
 690
 691static int crypto_rfc4106_setkey(struct crypto_aead *parent, const u8 *key,
 692				 unsigned int keylen)
 693{
 694	struct crypto_rfc4106_ctx *ctx = crypto_aead_ctx(parent);
 695	struct crypto_aead *child = ctx->child;
 696
 697	if (keylen < 4)
 698		return -EINVAL;
 699
 700	keylen -= 4;
 701	memcpy(ctx->nonce, key + keylen, 4);
 702
 703	crypto_aead_clear_flags(child, CRYPTO_TFM_REQ_MASK);
 704	crypto_aead_set_flags(child, crypto_aead_get_flags(parent) &
 705				     CRYPTO_TFM_REQ_MASK);
 706	return crypto_aead_setkey(child, key, keylen);
 707}
 708
 709static int crypto_rfc4106_setauthsize(struct crypto_aead *parent,
 710				      unsigned int authsize)
 711{
 712	struct crypto_rfc4106_ctx *ctx = crypto_aead_ctx(parent);
 713	int err;
 714
 715	err = crypto_rfc4106_check_authsize(authsize);
 716	if (err)
 717		return err;
 718
 719	return crypto_aead_setauthsize(ctx->child, authsize);
 720}
 721
 722static struct aead_request *crypto_rfc4106_crypt(struct aead_request *req)
 723{
 724	struct crypto_rfc4106_req_ctx *rctx = aead_request_ctx(req);
 725	struct crypto_aead *aead = crypto_aead_reqtfm(req);
 726	struct crypto_rfc4106_ctx *ctx = crypto_aead_ctx(aead);
 727	struct aead_request *subreq = &rctx->subreq;
 728	struct crypto_aead *child = ctx->child;
 729	struct scatterlist *sg;
 730	u8 *iv = PTR_ALIGN((u8 *)(subreq + 1) + crypto_aead_reqsize(child),
 731			   crypto_aead_alignmask(child) + 1);
 732
 733	scatterwalk_map_and_copy(iv + GCM_AES_IV_SIZE, req->src, 0, req->assoclen - 8, 0);
 734
 735	memcpy(iv, ctx->nonce, 4);
 736	memcpy(iv + 4, req->iv, 8);
 737
 738	sg_init_table(rctx->src, 3);
 739	sg_set_buf(rctx->src, iv + GCM_AES_IV_SIZE, req->assoclen - 8);
 740	sg = scatterwalk_ffwd(rctx->src + 1, req->src, req->assoclen);
 741	if (sg != rctx->src + 1)
 742		sg_chain(rctx->src, 2, sg);
 743
 744	if (req->src != req->dst) {
 745		sg_init_table(rctx->dst, 3);
 746		sg_set_buf(rctx->dst, iv + GCM_AES_IV_SIZE, req->assoclen - 8);
 747		sg = scatterwalk_ffwd(rctx->dst + 1, req->dst, req->assoclen);
 748		if (sg != rctx->dst + 1)
 749			sg_chain(rctx->dst, 2, sg);
 750	}
 751
 752	aead_request_set_tfm(subreq, child);
 753	aead_request_set_callback(subreq, req->base.flags, req->base.complete,
 754				  req->base.data);
 755	aead_request_set_crypt(subreq, rctx->src,
 756			       req->src == req->dst ? rctx->src : rctx->dst,
 757			       req->cryptlen, iv);
 758	aead_request_set_ad(subreq, req->assoclen - 8);
 759
 760	return subreq;
 761}
 762
 763static int crypto_rfc4106_encrypt(struct aead_request *req)
 764{
 765	int err;
 766
 767	err = crypto_ipsec_check_assoclen(req->assoclen);
 768	if (err)
 769		return err;
 770
 771	req = crypto_rfc4106_crypt(req);
 772
 773	return crypto_aead_encrypt(req);
 774}
 775
 776static int crypto_rfc4106_decrypt(struct aead_request *req)
 777{
 778	int err;
 779
 780	err = crypto_ipsec_check_assoclen(req->assoclen);
 781	if (err)
 782		return err;
 783
 784	req = crypto_rfc4106_crypt(req);
 785
 786	return crypto_aead_decrypt(req);
 787}
 788
 789static int crypto_rfc4106_init_tfm(struct crypto_aead *tfm)
 790{
 791	struct aead_instance *inst = aead_alg_instance(tfm);
 792	struct crypto_aead_spawn *spawn = aead_instance_ctx(inst);
 793	struct crypto_rfc4106_ctx *ctx = crypto_aead_ctx(tfm);
 794	struct crypto_aead *aead;
 795	unsigned long align;
 796
 797	aead = crypto_spawn_aead(spawn);
 798	if (IS_ERR(aead))
 799		return PTR_ERR(aead);
 800
 801	ctx->child = aead;
 802
 803	align = crypto_aead_alignmask(aead);
 804	align &= ~(crypto_tfm_ctx_alignment() - 1);
 805	crypto_aead_set_reqsize(
 806		tfm,
 807		sizeof(struct crypto_rfc4106_req_ctx) +
 808		ALIGN(crypto_aead_reqsize(aead), crypto_tfm_ctx_alignment()) +
 809		align + 24);
 810
 811	return 0;
 812}
 813
 814static void crypto_rfc4106_exit_tfm(struct crypto_aead *tfm)
 815{
 816	struct crypto_rfc4106_ctx *ctx = crypto_aead_ctx(tfm);
 817
 818	crypto_free_aead(ctx->child);
 819}
 820
 821static void crypto_rfc4106_free(struct aead_instance *inst)
 822{
 823	crypto_drop_aead(aead_instance_ctx(inst));
 824	kfree(inst);
 825}
 826
 827static int crypto_rfc4106_create(struct crypto_template *tmpl,
 828				 struct rtattr **tb)
 829{
 830	u32 mask;
 831	struct aead_instance *inst;
 832	struct crypto_aead_spawn *spawn;
 833	struct aead_alg *alg;
 834	int err;
 835
 836	err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_AEAD, &mask);
 837	if (err)
 838		return err;
 839
 840	inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
 841	if (!inst)
 842		return -ENOMEM;
 843
 844	spawn = aead_instance_ctx(inst);
 845	err = crypto_grab_aead(spawn, aead_crypto_instance(inst),
 846			       crypto_attr_alg_name(tb[1]), 0, mask);
 847	if (err)
 848		goto err_free_inst;
 849
 850	alg = crypto_spawn_aead_alg(spawn);
 851
 852	err = -EINVAL;
 853
 854	/* Underlying IV size must be 12. */
 855	if (crypto_aead_alg_ivsize(alg) != GCM_AES_IV_SIZE)
 856		goto err_free_inst;
 857
 858	/* Not a stream cipher? */
 859	if (alg->base.cra_blocksize != 1)
 860		goto err_free_inst;
 861
 862	err = -ENAMETOOLONG;
 863	if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
 864		     "rfc4106(%s)", alg->base.cra_name) >=
 865	    CRYPTO_MAX_ALG_NAME ||
 866	    snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
 867		     "rfc4106(%s)", alg->base.cra_driver_name) >=
 868	    CRYPTO_MAX_ALG_NAME)
 869		goto err_free_inst;
 870
 871	inst->alg.base.cra_priority = alg->base.cra_priority;
 872	inst->alg.base.cra_blocksize = 1;
 873	inst->alg.base.cra_alignmask = alg->base.cra_alignmask;
 874
 875	inst->alg.base.cra_ctxsize = sizeof(struct crypto_rfc4106_ctx);
 876
 877	inst->alg.ivsize = GCM_RFC4106_IV_SIZE;
 878	inst->alg.chunksize = crypto_aead_alg_chunksize(alg);
 879	inst->alg.maxauthsize = crypto_aead_alg_maxauthsize(alg);
 880
 881	inst->alg.init = crypto_rfc4106_init_tfm;
 882	inst->alg.exit = crypto_rfc4106_exit_tfm;
 883
 884	inst->alg.setkey = crypto_rfc4106_setkey;
 885	inst->alg.setauthsize = crypto_rfc4106_setauthsize;
 886	inst->alg.encrypt = crypto_rfc4106_encrypt;
 887	inst->alg.decrypt = crypto_rfc4106_decrypt;
 888
 889	inst->free = crypto_rfc4106_free;
 890
 891	err = aead_register_instance(tmpl, inst);
 892	if (err) {
 893err_free_inst:
 894		crypto_rfc4106_free(inst);
 895	}
 896	return err;
 897}
 898
 899static int crypto_rfc4543_setkey(struct crypto_aead *parent, const u8 *key,
 900				 unsigned int keylen)
 901{
 902	struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(parent);
 903	struct crypto_aead *child = ctx->child;
 904
 905	if (keylen < 4)
 906		return -EINVAL;
 907
 908	keylen -= 4;
 909	memcpy(ctx->nonce, key + keylen, 4);
 910
 911	crypto_aead_clear_flags(child, CRYPTO_TFM_REQ_MASK);
 912	crypto_aead_set_flags(child, crypto_aead_get_flags(parent) &
 913				     CRYPTO_TFM_REQ_MASK);
 914	return crypto_aead_setkey(child, key, keylen);
 915}
 916
 917static int crypto_rfc4543_setauthsize(struct crypto_aead *parent,
 918				      unsigned int authsize)
 919{
 920	struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(parent);
 921
 922	if (authsize != 16)
 923		return -EINVAL;
 924
 925	return crypto_aead_setauthsize(ctx->child, authsize);
 926}
 927
 928static int crypto_rfc4543_crypt(struct aead_request *req, bool enc)
 929{
 930	struct crypto_aead *aead = crypto_aead_reqtfm(req);
 931	struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(aead);
 932	struct crypto_rfc4543_req_ctx *rctx = aead_request_ctx(req);
 933	struct aead_request *subreq = &rctx->subreq;
 934	unsigned int authsize = crypto_aead_authsize(aead);
 935	u8 *iv = PTR_ALIGN((u8 *)(rctx + 1) + crypto_aead_reqsize(ctx->child),
 936			   crypto_aead_alignmask(ctx->child) + 1);
 937	int err;
 938
 939	if (req->src != req->dst) {
 940		err = crypto_rfc4543_copy_src_to_dst(req, enc);
 941		if (err)
 942			return err;
 943	}
 944
 945	memcpy(iv, ctx->nonce, 4);
 946	memcpy(iv + 4, req->iv, 8);
 947
 948	aead_request_set_tfm(subreq, ctx->child);
 949	aead_request_set_callback(subreq, req->base.flags,
 950				  req->base.complete, req->base.data);
 951	aead_request_set_crypt(subreq, req->src, req->dst,
 952			       enc ? 0 : authsize, iv);
 953	aead_request_set_ad(subreq, req->assoclen + req->cryptlen -
 954				    subreq->cryptlen);
 955
 956	return enc ? crypto_aead_encrypt(subreq) : crypto_aead_decrypt(subreq);
 957}
 958
 959static int crypto_rfc4543_copy_src_to_dst(struct aead_request *req, bool enc)
 960{
 961	struct crypto_aead *aead = crypto_aead_reqtfm(req);
 962	struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(aead);
 963	unsigned int authsize = crypto_aead_authsize(aead);
 964	unsigned int nbytes = req->assoclen + req->cryptlen -
 965			      (enc ? 0 : authsize);
 966	SYNC_SKCIPHER_REQUEST_ON_STACK(nreq, ctx->null);
 967
 968	skcipher_request_set_sync_tfm(nreq, ctx->null);
 969	skcipher_request_set_callback(nreq, req->base.flags, NULL, NULL);
 970	skcipher_request_set_crypt(nreq, req->src, req->dst, nbytes, NULL);
 971
 972	return crypto_skcipher_encrypt(nreq);
 973}
 974
 975static int crypto_rfc4543_encrypt(struct aead_request *req)
 976{
 977	return crypto_ipsec_check_assoclen(req->assoclen) ?:
 978	       crypto_rfc4543_crypt(req, true);
 979}
 980
 981static int crypto_rfc4543_decrypt(struct aead_request *req)
 982{
 983	return crypto_ipsec_check_assoclen(req->assoclen) ?:
 984	       crypto_rfc4543_crypt(req, false);
 985}
 986
 987static int crypto_rfc4543_init_tfm(struct crypto_aead *tfm)
 988{
 989	struct aead_instance *inst = aead_alg_instance(tfm);
 990	struct crypto_rfc4543_instance_ctx *ictx = aead_instance_ctx(inst);
 991	struct crypto_aead_spawn *spawn = &ictx->aead;
 992	struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(tfm);
 993	struct crypto_aead *aead;
 994	struct crypto_sync_skcipher *null;
 995	unsigned long align;
 996	int err = 0;
 997
 998	aead = crypto_spawn_aead(spawn);
 999	if (IS_ERR(aead))
1000		return PTR_ERR(aead);
1001
1002	null = crypto_get_default_null_skcipher();
1003	err = PTR_ERR(null);
1004	if (IS_ERR(null))
1005		goto err_free_aead;
1006
1007	ctx->child = aead;
1008	ctx->null = null;
1009
1010	align = crypto_aead_alignmask(aead);
1011	align &= ~(crypto_tfm_ctx_alignment() - 1);
1012	crypto_aead_set_reqsize(
1013		tfm,
1014		sizeof(struct crypto_rfc4543_req_ctx) +
1015		ALIGN(crypto_aead_reqsize(aead), crypto_tfm_ctx_alignment()) +
1016		align + GCM_AES_IV_SIZE);
1017
1018	return 0;
1019
1020err_free_aead:
1021	crypto_free_aead(aead);
1022	return err;
1023}
1024
1025static void crypto_rfc4543_exit_tfm(struct crypto_aead *tfm)
1026{
1027	struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(tfm);
1028
1029	crypto_free_aead(ctx->child);
1030	crypto_put_default_null_skcipher();
1031}
1032
1033static void crypto_rfc4543_free(struct aead_instance *inst)
1034{
1035	struct crypto_rfc4543_instance_ctx *ctx = aead_instance_ctx(inst);
1036
1037	crypto_drop_aead(&ctx->aead);
1038
1039	kfree(inst);
1040}
1041
1042static int crypto_rfc4543_create(struct crypto_template *tmpl,
1043				struct rtattr **tb)
1044{
1045	u32 mask;
1046	struct aead_instance *inst;
1047	struct aead_alg *alg;
1048	struct crypto_rfc4543_instance_ctx *ctx;
1049	int err;
1050
1051	err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_AEAD, &mask);
1052	if (err)
1053		return err;
1054
1055	inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
1056	if (!inst)
1057		return -ENOMEM;
1058
1059	ctx = aead_instance_ctx(inst);
1060	err = crypto_grab_aead(&ctx->aead, aead_crypto_instance(inst),
1061			       crypto_attr_alg_name(tb[1]), 0, mask);
1062	if (err)
1063		goto err_free_inst;
1064
1065	alg = crypto_spawn_aead_alg(&ctx->aead);
1066
1067	err = -EINVAL;
1068
1069	/* Underlying IV size must be 12. */
1070	if (crypto_aead_alg_ivsize(alg) != GCM_AES_IV_SIZE)
1071		goto err_free_inst;
1072
1073	/* Not a stream cipher? */
1074	if (alg->base.cra_blocksize != 1)
1075		goto err_free_inst;
1076
1077	err = -ENAMETOOLONG;
1078	if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
1079		     "rfc4543(%s)", alg->base.cra_name) >=
1080	    CRYPTO_MAX_ALG_NAME ||
1081	    snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
1082		     "rfc4543(%s)", alg->base.cra_driver_name) >=
1083	    CRYPTO_MAX_ALG_NAME)
1084		goto err_free_inst;
1085
1086	inst->alg.base.cra_priority = alg->base.cra_priority;
1087	inst->alg.base.cra_blocksize = 1;
1088	inst->alg.base.cra_alignmask = alg->base.cra_alignmask;
1089
1090	inst->alg.base.cra_ctxsize = sizeof(struct crypto_rfc4543_ctx);
1091
1092	inst->alg.ivsize = GCM_RFC4543_IV_SIZE;
1093	inst->alg.chunksize = crypto_aead_alg_chunksize(alg);
1094	inst->alg.maxauthsize = crypto_aead_alg_maxauthsize(alg);
1095
1096	inst->alg.init = crypto_rfc4543_init_tfm;
1097	inst->alg.exit = crypto_rfc4543_exit_tfm;
1098
1099	inst->alg.setkey = crypto_rfc4543_setkey;
1100	inst->alg.setauthsize = crypto_rfc4543_setauthsize;
1101	inst->alg.encrypt = crypto_rfc4543_encrypt;
1102	inst->alg.decrypt = crypto_rfc4543_decrypt;
1103
1104	inst->free = crypto_rfc4543_free;
1105
1106	err = aead_register_instance(tmpl, inst);
1107	if (err) {
1108err_free_inst:
1109		crypto_rfc4543_free(inst);
1110	}
1111	return err;
1112}
1113
1114static struct crypto_template crypto_gcm_tmpls[] = {
1115	{
1116		.name = "gcm_base",
1117		.create = crypto_gcm_base_create,
1118		.module = THIS_MODULE,
1119	}, {
1120		.name = "gcm",
1121		.create = crypto_gcm_create,
1122		.module = THIS_MODULE,
1123	}, {
1124		.name = "rfc4106",
1125		.create = crypto_rfc4106_create,
1126		.module = THIS_MODULE,
1127	}, {
1128		.name = "rfc4543",
1129		.create = crypto_rfc4543_create,
1130		.module = THIS_MODULE,
1131	},
1132};
1133
1134static int __init crypto_gcm_module_init(void)
1135{
1136	int err;
1137
1138	gcm_zeroes = kzalloc(sizeof(*gcm_zeroes), GFP_KERNEL);
1139	if (!gcm_zeroes)
1140		return -ENOMEM;
1141
1142	sg_init_one(&gcm_zeroes->sg, gcm_zeroes->buf, sizeof(gcm_zeroes->buf));
1143
1144	err = crypto_register_templates(crypto_gcm_tmpls,
1145					ARRAY_SIZE(crypto_gcm_tmpls));
1146	if (err)
1147		kfree(gcm_zeroes);
1148
1149	return err;
1150}
1151
1152static void __exit crypto_gcm_module_exit(void)
1153{
1154	kfree(gcm_zeroes);
1155	crypto_unregister_templates(crypto_gcm_tmpls,
1156				    ARRAY_SIZE(crypto_gcm_tmpls));
1157}
1158
1159subsys_initcall(crypto_gcm_module_init);
1160module_exit(crypto_gcm_module_exit);
1161
1162MODULE_LICENSE("GPL");
1163MODULE_DESCRIPTION("Galois/Counter Mode");
1164MODULE_AUTHOR("Mikko Herranen <mh1@iki.fi>");
1165MODULE_ALIAS_CRYPTO("gcm_base");
1166MODULE_ALIAS_CRYPTO("rfc4106");
1167MODULE_ALIAS_CRYPTO("rfc4543");
1168MODULE_ALIAS_CRYPTO("gcm");