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(struct crypto_async_request *areq, 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(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
 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(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
 282 out:
 283         aead_request_complete(req, err);
 284 }
 285
 286 static 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
 301 static 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
 312 out:
 313         aead_request_complete(req, err);
 314 }
 315
 316 static 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
 329 static 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
 341 out:
 342         aead_request_complete(req, err);
 343 }
 344
 345 static 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
 358 static 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
 369 out:
 370         aead_request_complete(req, err);
 371 }
 372
 373 static 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
 383 static 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
 394 out:
 395         aead_request_complete(req, err);
 396 }
 397
 398 static 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
 411 static 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
 424 static 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
 436 static 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
 447 out:
 448         aead_request_complete(req, err);
 449 }
 450
 451 static 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
 465 static 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
 480 static 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
 490 static 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
 501 static 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
 521 static 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
 554 err_free_hash:
 555         crypto_free_ahash(ghash);
 556         return err;
 557 }
 558
 559 static 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
 567 static 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
 576 static 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) {
 652 err_free_inst:
 653                 crypto_gcm_free(inst);
 654         }
 655         return err;
 656 }
 657
 658 static 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
 674 static 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
 691 static 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
 709 static 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
 722 static 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
 763 static 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
 776 static 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
 789 static 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
 814 static 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
 821 static void crypto_rfc4106_free(struct aead_instance *inst)
 822 {
 823         crypto_drop_aead(aead_instance_ctx(inst));
 824         kfree(inst);
 825 }
 826
 827 static 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) {
 893 err_free_inst:
 894                 crypto_rfc4106_free(inst);
 895         }
 896         return err;
 897 }
 898
 899 static 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
 917 static 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
 928 static 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
 959 static 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
 975 static 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
 981 static 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
 987 static 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
1020 err_free_aead:
1021         crypto_free_aead(aead);
1022         return err;
1023 }
1024
1025 static 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
1033 static 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
1042 static 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) {
1108 err_free_inst:
1109                 crypto_rfc4543_free(inst);
1110         }
1111         return err;
1112 }
1113
1114 static 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
1134 static 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
1152 static 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
1159 subsys_initcall(crypto_gcm_module_init);
1160 module_exit(crypto_gcm_module_exit);
1161
1162 MODULE_LICENSE("GPL");
1163 MODULE_DESCRIPTION("Galois/Counter Mode");
1164 MODULE_AUTHOR("Mikko Herranen <mh1@iki.fi>");
1165 MODULE_ALIAS_CRYPTO("gcm_base");
1166 MODULE_ALIAS_CRYPTO("rfc4106");
1167 MODULE_ALIAS_CRYPTO("rfc4543");
1168 MODULE_ALIAS_CRYPTO("gcm");