crypto/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/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
  22 struct gcm_instance_ctx {
  23         struct crypto_skcipher_spawn ctr;
  24         struct crypto_ahash_spawn ghash;
  25 };
  26
  27 struct crypto_gcm_ctx {
  28         struct crypto_skcipher *ctr;
  29         struct crypto_ahash *ghash;
  30 };
  31
  32 struct crypto_rfc4106_ctx {
  33         struct crypto_aead *child;
  34         u8 nonce[4];
  35 };
  36
  37 struct crypto_rfc4106_req_ctx {
  38         struct scatterlist src[3];
  39         struct scatterlist dst[3];
  40         struct aead_request subreq;
  41 };
  42
  43 struct crypto_rfc4543_instance_ctx {
  44         struct crypto_aead_spawn aead;
  45 };
  46
  47 struct crypto_rfc4543_ctx {
  48         struct crypto_aead *child;
  49         struct crypto_sync_skcipher *null;
  50         u8 nonce[4];
  51 };
  52
  53 struct crypto_rfc4543_req_ctx {
  54         struct aead_request subreq;
  55 };
  56
  57 struct crypto_gcm_ghash_ctx {
  58         unsigned int cryptlen;
  59         struct scatterlist *src;
  60         int (*complete)(struct aead_request *req, u32 flags);
  61 };
  62
  63 struct 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
  77 static struct {
  78         u8 buf[16];
  79         struct scatterlist sg;
  80 } *gcm_zeroes;
  81
  82 static int crypto_rfc4543_copy_src_to_dst(struct aead_request *req, bool enc);
  83
  84 static 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
  92 static 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));
 141 out:
 142         kfree_sensitive(data);
 143         return err;
 144 }
 145
 146 static int crypto_gcm_setauthsize(struct crypto_aead *tfm,
 147                                   unsigned int authsize)
 148 {
 149         return crypto_gcm_check_authsize(authsize);
 150 }
 151
 152 static 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
 177 static 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
 194 static inline unsigned int gcm_remain(unsigned int len)
 195 {
 196         len &= 0xfU;
 197         return len ? 16 - len : 0;
 198 }
 199
 200 static void gcm_hash_len_done(void *data, int err);
 201
 202 static 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
 216 static 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
 223 static 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
 241 static 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
 249 static 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
 260 out:
 261         aead_request_complete(req, err);
 262 }
 263
 264 static 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
 270 static 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
 281 out:
 282         aead_request_complete(req, err);
 283 }
 284
 285 static 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
 300 static 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
 311 out:
 312         aead_request_complete(req, err);
 313 }
 314
 315 static 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
 328 static 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
 339 out:
 340         aead_request_complete(req, err);
 341 }
 342
 343 static 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
 356 static 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
 367 out:
 368         aead_request_complete(req, err);
 369 }
 370
 371 static 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
 381 static 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
 392 out:
 393         aead_request_complete(req, err);
 394 }
 395
 396 static 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
 409 static 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
 422 static 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
 434 static 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
 445 out:
 446         aead_request_complete(req, err);
 447 }
 448
 449 static 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
 463 static 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
 478 static 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
 488 static 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
 499 static 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
 519 static 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
 552 err_free_hash:
 553         crypto_free_ahash(ghash);
 554         return err;
 555 }
 556
 557 static 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
 565 static 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
 574 static 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) {
 648 err_free_inst:
 649                 crypto_gcm_free(inst);
 650         }
 651         return err;
 652 }
 653
 654 static 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
 670 static 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
 687 static 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
 705 static 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
 718 static 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
 759 static 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
 772 static 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
 785 static 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
 810 static 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
 817 static void crypto_rfc4106_free(struct aead_instance *inst)
 818 {
 819         crypto_drop_aead(aead_instance_ctx(inst));
 820         kfree(inst);
 821 }
 822
 823 static 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) {
 889 err_free_inst:
 890                 crypto_rfc4106_free(inst);
 891         }
 892         return err;
 893 }
 894
 895 static 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
 913 static 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
 924 static 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
 955 static 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
 971 static 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
 977 static 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
 983 static 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
1016 err_free_aead:
1017         crypto_free_aead(aead);
1018         return err;
1019 }
1020
1021 static 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
1029 static 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
1038 static 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) {
1104 err_free_inst:
1105                 crypto_rfc4543_free(inst);
1106         }
1107         return err;
1108 }
1109
1110 static 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
1130 static 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
1148 static 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
1155 subsys_initcall(crypto_gcm_module_init);
1156 module_exit(crypto_gcm_module_exit);
1157
1158 MODULE_LICENSE("GPL");
1159 MODULE_DESCRIPTION("Galois/Counter Mode");
1160 MODULE_AUTHOR("Mikko Herranen <mh1@iki.fi>");
1161 MODULE_ALIAS_CRYPTO("gcm_base");
1162 MODULE_ALIAS_CRYPTO("rfc4106");
1163 MODULE_ALIAS_CRYPTO("rfc4543");
1164 MODULE_ALIAS_CRYPTO("gcm");