crypto/seqiv.c

   1 /*
   2  * seqiv: Sequence Number IV Generator
   3  *
   4  * This generator generates an IV based on a sequence number by xoring it
   5  * with a salt.  This algorithm is mainly useful for CTR and similar modes.
   6  *
   7  * Copyright (c) 2007 Herbert Xu <herbert@gondor.apana.org.au>
   8  *
   9  * This program is free software; you can redistribute it and/or modify it
  10  * under the terms of the GNU General Public License as published by the Free
  11  * Software Foundation; either version 2 of the License, or (at your option)
  12  * any later version.
  13  *
  14  */
  15
  16 #include <crypto/internal/aead.h>
  17 #include <crypto/internal/skcipher.h>
  18 #include <crypto/null.h>
  19 #include <crypto/rng.h>
  20 #include <crypto/scatterwalk.h>
  21 #include <linux/err.h>
  22 #include <linux/init.h>
  23 #include <linux/kernel.h>
  24 #include <linux/module.h>
  25 #include <linux/slab.h>
  26 #include <linux/spinlock.h>
  27 #include <linux/string.h>
  28
  29 struct seqiv_ctx {
  30         spinlock_t lock;
  31         u8 salt[] __attribute__ ((aligned(__alignof__(u32))));
  32 };
  33
  34 struct seqiv_aead_ctx {
  35         struct crypto_aead *child;
  36         spinlock_t lock;
  37         struct crypto_blkcipher *null;
  38         u8 salt[] __attribute__ ((aligned(__alignof__(u32))));
  39 };
  40
  41 static int seqiv_aead_setkey(struct crypto_aead *tfm,
  42                              const u8 *key, unsigned int keylen)
  43 {
  44         struct seqiv_aead_ctx *ctx = crypto_aead_ctx(tfm);
  45
  46         return crypto_aead_setkey(ctx->child, key, keylen);
  47 }
  48
  49 static int seqiv_aead_setauthsize(struct crypto_aead *tfm,
  50                                   unsigned int authsize)
  51 {
  52         struct seqiv_aead_ctx *ctx = crypto_aead_ctx(tfm);
  53
  54         return crypto_aead_setauthsize(ctx->child, authsize);
  55 }
  56
  57 static void seqiv_complete2(struct skcipher_givcrypt_request *req, int err)
  58 {
  59         struct ablkcipher_request *subreq = skcipher_givcrypt_reqctx(req);
  60         struct crypto_ablkcipher *geniv;
  61
  62         if (err == -EINPROGRESS)
  63                 return;
  64
  65         if (err)
  66                 goto out;
  67
  68         geniv = skcipher_givcrypt_reqtfm(req);
  69         memcpy(req->creq.info, subreq->info, crypto_ablkcipher_ivsize(geniv));
  70
  71 out:
  72         kfree(subreq->info);
  73 }
  74
  75 static void seqiv_complete(struct crypto_async_request *base, int err)
  76 {
  77         struct skcipher_givcrypt_request *req = base->data;
  78
  79         seqiv_complete2(req, err);
  80         skcipher_givcrypt_complete(req, err);
  81 }
  82
  83 static void seqiv_aead_complete2(struct aead_givcrypt_request *req, int err)
  84 {
  85         struct aead_request *subreq = aead_givcrypt_reqctx(req);
  86         struct crypto_aead *geniv;
  87
  88         if (err == -EINPROGRESS)
  89                 return;
  90
  91         if (err)
  92                 goto out;
  93
  94         geniv = aead_givcrypt_reqtfm(req);
  95         memcpy(req->areq.iv, subreq->iv, crypto_aead_ivsize(geniv));
  96
  97 out:
  98         kfree(subreq->iv);
  99 }
 100
 101 static void seqiv_aead_complete(struct crypto_async_request *base, int err)
 102 {
 103         struct aead_givcrypt_request *req = base->data;
 104
 105         seqiv_aead_complete2(req, err);
 106         aead_givcrypt_complete(req, err);
 107 }
 108
 109 static void seqiv_aead_encrypt_complete2(struct aead_request *req, int err)
 110 {
 111         struct aead_request *subreq = aead_request_ctx(req);
 112         struct crypto_aead *geniv;
 113
 114         if (err == -EINPROGRESS)
 115                 return;
 116
 117         if (err)
 118                 goto out;
 119
 120         geniv = crypto_aead_reqtfm(req);
 121         memcpy(req->iv, subreq->iv, crypto_aead_ivsize(geniv));
 122
 123 out:
 124         kzfree(subreq->iv);
 125 }
 126
 127 static void seqiv_aead_encrypt_complete(struct crypto_async_request *base,
 128                                         int err)
 129 {
 130         struct aead_request *req = base->data;
 131
 132         seqiv_aead_encrypt_complete2(req, err);
 133         aead_request_complete(req, err);
 134 }
 135
 136 static void seqiv_geniv(struct seqiv_ctx *ctx, u8 *info, u64 seq,
 137                         unsigned int ivsize)
 138 {
 139         unsigned int len = ivsize;
 140
 141         if (ivsize > sizeof(u64)) {
 142                 memset(info, 0, ivsize - sizeof(u64));
 143                 len = sizeof(u64);
 144         }
 145         seq = cpu_to_be64(seq);
 146         memcpy(info + ivsize - len, &seq, len);
 147         crypto_xor(info, ctx->salt, ivsize);
 148 }
 149
 150 static int seqiv_givencrypt(struct skcipher_givcrypt_request *req)
 151 {
 152         struct crypto_ablkcipher *geniv = skcipher_givcrypt_reqtfm(req);
 153         struct seqiv_ctx *ctx = crypto_ablkcipher_ctx(geniv);
 154         struct ablkcipher_request *subreq = skcipher_givcrypt_reqctx(req);
 155         crypto_completion_t compl;
 156         void *data;
 157         u8 *info;
 158         unsigned int ivsize;
 159         int err;
 160
 161         ablkcipher_request_set_tfm(subreq, skcipher_geniv_cipher(geniv));
 162
 163         compl = req->creq.base.complete;
 164         data = req->creq.base.data;
 165         info = req->creq.info;
 166
 167         ivsize = crypto_ablkcipher_ivsize(geniv);
 168
 169         if (unlikely(!IS_ALIGNED((unsigned long)info,
 170                                  crypto_ablkcipher_alignmask(geniv) + 1))) {
 171                 info = kmalloc(ivsize, req->creq.base.flags &
 172                                        CRYPTO_TFM_REQ_MAY_SLEEP ? GFP_KERNEL:
 173                                                                   GFP_ATOMIC);
 174                 if (!info)
 175                         return -ENOMEM;
 176
 177                 compl = seqiv_complete;
 178                 data = req;
 179         }
 180
 181         ablkcipher_request_set_callback(subreq, req->creq.base.flags, compl,
 182                                         data);
 183         ablkcipher_request_set_crypt(subreq, req->creq.src, req->creq.dst,
 184                                      req->creq.nbytes, info);
 185
 186         seqiv_geniv(ctx, info, req->seq, ivsize);
 187         memcpy(req->giv, info, ivsize);
 188
 189         err = crypto_ablkcipher_encrypt(subreq);
 190         if (unlikely(info != req->creq.info))
 191                 seqiv_complete2(req, err);
 192         return err;
 193 }
 194
 195 static int seqiv_aead_givencrypt(struct aead_givcrypt_request *req)
 196 {
 197         struct crypto_aead *geniv = aead_givcrypt_reqtfm(req);
 198         struct seqiv_ctx *ctx = crypto_aead_ctx(geniv);
 199         struct aead_request *areq = &req->areq;
 200         struct aead_request *subreq = aead_givcrypt_reqctx(req);
 201         crypto_completion_t compl;
 202         void *data;
 203         u8 *info;
 204         unsigned int ivsize;
 205         int err;
 206
 207         aead_request_set_tfm(subreq, aead_geniv_base(geniv));
 208
 209         compl = areq->base.complete;
 210         data = areq->base.data;
 211         info = areq->iv;
 212
 213         ivsize = crypto_aead_ivsize(geniv);
 214
 215         if (unlikely(!IS_ALIGNED((unsigned long)info,
 216                                  crypto_aead_alignmask(geniv) + 1))) {
 217                 info = kmalloc(ivsize, areq->base.flags &
 218                                        CRYPTO_TFM_REQ_MAY_SLEEP ? GFP_KERNEL:
 219                                                                   GFP_ATOMIC);
 220                 if (!info)
 221                         return -ENOMEM;
 222
 223                 compl = seqiv_aead_complete;
 224                 data = req;
 225         }
 226
 227         aead_request_set_callback(subreq, areq->base.flags, compl, data);
 228         aead_request_set_crypt(subreq, areq->src, areq->dst, areq->cryptlen,
 229                                info);
 230         aead_request_set_assoc(subreq, areq->assoc, areq->assoclen);
 231
 232         seqiv_geniv(ctx, info, req->seq, ivsize);
 233         memcpy(req->giv, info, ivsize);
 234
 235         err = crypto_aead_encrypt(subreq);
 236         if (unlikely(info != areq->iv))
 237                 seqiv_aead_complete2(req, err);
 238         return err;
 239 }
 240
 241 static int seqiv_aead_encrypt_compat(struct aead_request *req)
 242 {
 243         struct crypto_aead *geniv = crypto_aead_reqtfm(req);
 244         struct seqiv_aead_ctx *ctx = crypto_aead_ctx(geniv);
 245         struct aead_request *subreq = aead_request_ctx(req);
 246         crypto_completion_t compl;
 247         void *data;
 248         u8 *info;
 249         unsigned int ivsize;
 250         int err;
 251
 252         aead_request_set_tfm(subreq, ctx->child);
 253
 254         compl = req->base.complete;
 255         data = req->base.data;
 256         info = req->iv;
 257
 258         ivsize = crypto_aead_ivsize(geniv);
 259
 260         if (unlikely(!IS_ALIGNED((unsigned long)info,
 261                                  crypto_aead_alignmask(geniv) + 1))) {
 262                 info = kmalloc(ivsize, req->base.flags &
 263                                        CRYPTO_TFM_REQ_MAY_SLEEP ? GFP_KERNEL:
 264                                                                   GFP_ATOMIC);
 265                 if (!info)
 266                         return -ENOMEM;
 267
 268                 memcpy(info, req->iv, ivsize);
 269                 compl = seqiv_aead_encrypt_complete;
 270                 data = req;
 271         }
 272
 273         aead_request_set_callback(subreq, req->base.flags, compl, data);
 274         aead_request_set_crypt(subreq, req->src, req->dst,
 275                                req->cryptlen - ivsize, info);
 276         aead_request_set_ad(subreq, req->assoclen, ivsize);
 277
 278         crypto_xor(info, ctx->salt, ivsize);
 279         scatterwalk_map_and_copy(info, req->dst, req->assoclen, ivsize, 1);
 280
 281         err = crypto_aead_encrypt(subreq);
 282         if (unlikely(info != req->iv))
 283                 seqiv_aead_encrypt_complete2(req, err);
 284         return err;
 285 }
 286
 287 static int seqiv_aead_encrypt(struct aead_request *req)
 288 {
 289         struct crypto_aead *geniv = crypto_aead_reqtfm(req);
 290         struct seqiv_aead_ctx *ctx = crypto_aead_ctx(geniv);
 291         struct aead_request *subreq = aead_request_ctx(req);
 292         crypto_completion_t compl;
 293         void *data;
 294         u8 *info;
 295         unsigned int ivsize;
 296         int err;
 297
 298         aead_request_set_tfm(subreq, ctx->child);
 299
 300         compl = req->base.complete;
 301         data = req->base.data;
 302         info = req->iv;
 303
 304         ivsize = crypto_aead_ivsize(geniv);
 305
 306         if (req->src != req->dst) {
 307                 struct scatterlist src[2];
 308                 struct scatterlist dst[2];
 309                 struct blkcipher_desc desc = {
 310                         .tfm = ctx->null,
 311                 };
 312
 313                 err = crypto_blkcipher_encrypt(
 314                         &desc,
 315                         scatterwalk_ffwd(dst, req->dst,
 316                                          req->assoclen + ivsize),
 317                         scatterwalk_ffwd(src, req->src,
 318                                          req->assoclen + ivsize),
 319                         req->cryptlen - ivsize);
 320                 if (err)
 321                         return err;
 322         }
 323
 324         if (unlikely(!IS_ALIGNED((unsigned long)info,
 325                                  crypto_aead_alignmask(geniv) + 1))) {
 326                 info = kmalloc(ivsize, req->base.flags &
 327                                        CRYPTO_TFM_REQ_MAY_SLEEP ? GFP_KERNEL:
 328                                                                   GFP_ATOMIC);
 329                 if (!info)
 330                         return -ENOMEM;
 331
 332                 memcpy(info, req->iv, ivsize);
 333                 compl = seqiv_aead_encrypt_complete;
 334                 data = req;
 335         }
 336
 337         aead_request_set_callback(subreq, req->base.flags, compl, data);
 338         aead_request_set_crypt(subreq, req->dst, req->dst,
 339                                req->cryptlen - ivsize, info);
 340         aead_request_set_ad(subreq, req->assoclen + ivsize, 0);
 341
 342         crypto_xor(info, ctx->salt, ivsize);
 343         scatterwalk_map_and_copy(info, req->dst, req->assoclen, ivsize, 1);
 344
 345         err = crypto_aead_encrypt(subreq);
 346         if (unlikely(info != req->iv))
 347                 seqiv_aead_encrypt_complete2(req, err);
 348         return err;
 349 }
 350
 351 static int seqiv_aead_decrypt_compat(struct aead_request *req)
 352 {
 353         struct crypto_aead *geniv = crypto_aead_reqtfm(req);
 354         struct seqiv_aead_ctx *ctx = crypto_aead_ctx(geniv);
 355         struct aead_request *subreq = aead_request_ctx(req);
 356         crypto_completion_t compl;
 357         void *data;
 358         unsigned int ivsize;
 359
 360         aead_request_set_tfm(subreq, ctx->child);
 361
 362         compl = req->base.complete;
 363         data = req->base.data;
 364
 365         ivsize = crypto_aead_ivsize(geniv);
 366
 367         aead_request_set_callback(subreq, req->base.flags, compl, data);
 368         aead_request_set_crypt(subreq, req->src, req->dst,
 369                                req->cryptlen - ivsize, req->iv);
 370         aead_request_set_ad(subreq, req->assoclen, ivsize);
 371
 372         scatterwalk_map_and_copy(req->iv, req->src, req->assoclen, ivsize, 0);
 373
 374         return crypto_aead_decrypt(subreq);
 375 }
 376
 377 static int seqiv_aead_decrypt(struct aead_request *req)
 378 {
 379         struct crypto_aead *geniv = crypto_aead_reqtfm(req);
 380         struct seqiv_aead_ctx *ctx = crypto_aead_ctx(geniv);
 381         struct aead_request *subreq = aead_request_ctx(req);
 382         crypto_completion_t compl;
 383         void *data;
 384         unsigned int ivsize;
 385
 386         aead_request_set_tfm(subreq, ctx->child);
 387
 388         compl = req->base.complete;
 389         data = req->base.data;
 390
 391         ivsize = crypto_aead_ivsize(geniv);
 392
 393         aead_request_set_callback(subreq, req->base.flags, compl, data);
 394         aead_request_set_crypt(subreq, req->src, req->dst,
 395                                req->cryptlen - ivsize, req->iv);
 396         aead_request_set_ad(subreq, req->assoclen + ivsize, 0);
 397
 398         scatterwalk_map_and_copy(req->iv, req->src, req->assoclen, ivsize, 0);
 399         if (req->src != req->dst)
 400                 scatterwalk_map_and_copy(req->iv, req->dst,
 401                                          req->assoclen, ivsize, 1);
 402
 403         return crypto_aead_decrypt(subreq);
 404 }
 405
 406 static int seqiv_givencrypt_first(struct skcipher_givcrypt_request *req)
 407 {
 408         struct crypto_ablkcipher *geniv = skcipher_givcrypt_reqtfm(req);
 409         struct seqiv_ctx *ctx = crypto_ablkcipher_ctx(geniv);
 410         int err = 0;
 411
 412         spin_lock_bh(&ctx->lock);
 413         if (crypto_ablkcipher_crt(geniv)->givencrypt != seqiv_givencrypt_first)
 414                 goto unlock;
 415
 416         crypto_ablkcipher_crt(geniv)->givencrypt = seqiv_givencrypt;
 417         err = crypto_rng_get_bytes(crypto_default_rng, ctx->salt,
 418                                    crypto_ablkcipher_ivsize(geniv));
 419
 420 unlock:
 421         spin_unlock_bh(&ctx->lock);
 422
 423         if (err)
 424                 return err;
 425
 426         return seqiv_givencrypt(req);
 427 }
 428
 429 static int seqiv_aead_givencrypt_first(struct aead_givcrypt_request *req)
 430 {
 431         struct crypto_aead *geniv = aead_givcrypt_reqtfm(req);
 432         struct seqiv_ctx *ctx = crypto_aead_ctx(geniv);
 433         int err = 0;
 434
 435         spin_lock_bh(&ctx->lock);
 436         if (crypto_aead_crt(geniv)->givencrypt != seqiv_aead_givencrypt_first)
 437                 goto unlock;
 438
 439         crypto_aead_crt(geniv)->givencrypt = seqiv_aead_givencrypt;
 440         err = crypto_rng_get_bytes(crypto_default_rng, ctx->salt,
 441                                    crypto_aead_ivsize(geniv));
 442
 443 unlock:
 444         spin_unlock_bh(&ctx->lock);
 445
 446         if (err)
 447                 return err;
 448
 449         return seqiv_aead_givencrypt(req);
 450 }
 451
 452 static int seqiv_aead_encrypt_compat_first(struct aead_request *req)
 453 {
 454         struct crypto_aead *geniv = crypto_aead_reqtfm(req);
 455         struct seqiv_aead_ctx *ctx = crypto_aead_ctx(geniv);
 456         int err = 0;
 457
 458         spin_lock_bh(&ctx->lock);
 459         if (geniv->encrypt != seqiv_aead_encrypt_compat_first)
 460                 goto unlock;
 461
 462         geniv->encrypt = seqiv_aead_encrypt_compat;
 463         err = crypto_rng_get_bytes(crypto_default_rng, ctx->salt,
 464                                    crypto_aead_ivsize(geniv));
 465
 466 unlock:
 467         spin_unlock_bh(&ctx->lock);
 468
 469         if (err)
 470                 return err;
 471
 472         return seqiv_aead_encrypt_compat(req);
 473 }
 474
 475 static int seqiv_aead_encrypt_first(struct aead_request *req)
 476 {
 477         struct crypto_aead *geniv = crypto_aead_reqtfm(req);
 478         struct seqiv_aead_ctx *ctx = crypto_aead_ctx(geniv);
 479         int err = 0;
 480
 481         spin_lock_bh(&ctx->lock);
 482         if (geniv->encrypt != seqiv_aead_encrypt_first)
 483                 goto unlock;
 484
 485         geniv->encrypt = seqiv_aead_encrypt;
 486         err = crypto_rng_get_bytes(crypto_default_rng, ctx->salt,
 487                                    crypto_aead_ivsize(geniv));
 488
 489 unlock:
 490         spin_unlock_bh(&ctx->lock);
 491
 492         if (err)
 493                 return err;
 494
 495         return seqiv_aead_encrypt(req);
 496 }
 497
 498 static int seqiv_init(struct crypto_tfm *tfm)
 499 {
 500         struct crypto_ablkcipher *geniv = __crypto_ablkcipher_cast(tfm);
 501         struct seqiv_ctx *ctx = crypto_ablkcipher_ctx(geniv);
 502
 503         spin_lock_init(&ctx->lock);
 504
 505         tfm->crt_ablkcipher.reqsize = sizeof(struct ablkcipher_request);
 506
 507         return skcipher_geniv_init(tfm);
 508 }
 509
 510 static int seqiv_old_aead_init(struct crypto_tfm *tfm)
 511 {
 512         struct crypto_aead *geniv = __crypto_aead_cast(tfm);
 513         struct seqiv_ctx *ctx = crypto_aead_ctx(geniv);
 514
 515         spin_lock_init(&ctx->lock);
 516
 517         crypto_aead_set_reqsize(__crypto_aead_cast(tfm),
 518                                 sizeof(struct aead_request));
 519
 520         return aead_geniv_init(tfm);
 521 }
 522
 523 static int seqiv_aead_compat_init(struct crypto_tfm *tfm)
 524 {
 525         struct crypto_aead *geniv = __crypto_aead_cast(tfm);
 526         struct seqiv_aead_ctx *ctx = crypto_aead_ctx(geniv);
 527         int err;
 528
 529         spin_lock_init(&ctx->lock);
 530
 531         crypto_aead_set_reqsize(geniv, sizeof(struct aead_request));
 532
 533         err = aead_geniv_init(tfm);
 534
 535         ctx->child = geniv->child;
 536         geniv->child = geniv;
 537
 538         return err;
 539 }
 540
 541 static int seqiv_aead_init(struct crypto_tfm *tfm)
 542 {
 543         struct crypto_aead *geniv = __crypto_aead_cast(tfm);
 544         struct seqiv_aead_ctx *ctx = crypto_aead_ctx(geniv);
 545         int err;
 546
 547         spin_lock_init(&ctx->lock);
 548
 549         crypto_aead_set_reqsize(geniv, sizeof(struct aead_request));
 550
 551         ctx->null = crypto_get_default_null_skcipher();
 552         err = PTR_ERR(ctx->null);
 553         if (IS_ERR(ctx->null))
 554                 goto out;
 555
 556         err = aead_geniv_init(tfm);
 557         if (err)
 558                 goto drop_null;
 559
 560         ctx->child = geniv->child;
 561         geniv->child = geniv;
 562
 563 out:
 564         return err;
 565
 566 drop_null:
 567         crypto_put_default_null_skcipher();
 568         goto out;
 569 }
 570
 571 static void seqiv_aead_compat_exit(struct crypto_tfm *tfm)
 572 {
 573         struct seqiv_aead_ctx *ctx = crypto_tfm_ctx(tfm);
 574
 575         crypto_free_aead(ctx->child);
 576 }
 577
 578 static void seqiv_aead_exit(struct crypto_tfm *tfm)
 579 {
 580         struct seqiv_aead_ctx *ctx = crypto_tfm_ctx(tfm);
 581
 582         crypto_free_aead(ctx->child);
 583         crypto_put_default_null_skcipher();
 584 }
 585
 586 static struct crypto_template seqiv_tmpl;
 587
 588 static struct crypto_instance *seqiv_ablkcipher_alloc(struct rtattr **tb)
 589 {
 590         struct crypto_instance *inst;
 591
 592         inst = skcipher_geniv_alloc(&seqiv_tmpl, tb, 0, 0);
 593
 594         if (IS_ERR(inst))
 595                 goto out;
 596
 597         if (inst->alg.cra_ablkcipher.ivsize < sizeof(u64)) {
 598                 skcipher_geniv_free(inst);
 599                 inst = ERR_PTR(-EINVAL);
 600                 goto out;
 601         }
 602
 603         inst->alg.cra_ablkcipher.givencrypt = seqiv_givencrypt_first;
 604
 605         inst->alg.cra_init = seqiv_init;
 606         inst->alg.cra_exit = skcipher_geniv_exit;
 607
 608         inst->alg.cra_ctxsize += inst->alg.cra_ablkcipher.ivsize;
 609         inst->alg.cra_ctxsize += sizeof(struct seqiv_ctx);
 610
 611 out:
 612         return inst;
 613 }
 614
 615 static struct crypto_instance *seqiv_old_aead_alloc(struct aead_instance *aead)
 616 {
 617         struct crypto_instance *inst = aead_crypto_instance(aead);
 618
 619         if (inst->alg.cra_aead.ivsize < sizeof(u64)) {
 620                 aead_geniv_free(aead);
 621                 return ERR_PTR(-EINVAL);
 622         }
 623
 624         inst->alg.cra_aead.givencrypt = seqiv_aead_givencrypt_first;
 625
 626         inst->alg.cra_init = seqiv_old_aead_init;
 627         inst->alg.cra_exit = aead_geniv_exit;
 628
 629         inst->alg.cra_ctxsize = inst->alg.cra_aead.ivsize;
 630         inst->alg.cra_ctxsize += sizeof(struct seqiv_ctx);
 631
 632         return inst;
 633 }
 634
 635 static struct crypto_instance *seqiv_aead_alloc(struct rtattr **tb)
 636 {
 637         struct aead_instance *inst;
 638         struct crypto_aead_spawn *spawn;
 639         struct aead_alg *alg;
 640
 641         inst = aead_geniv_alloc(&seqiv_tmpl, tb, 0, 0);
 642
 643         if (IS_ERR(inst))
 644                 goto out;
 645
 646         if (inst->alg.base.cra_aead.encrypt)
 647                 return seqiv_old_aead_alloc(inst);
 648
 649         if (inst->alg.ivsize < sizeof(u64)) {
 650                 aead_geniv_free(inst);
 651                 inst = ERR_PTR(-EINVAL);
 652                 goto out;
 653         }
 654
 655         spawn = aead_instance_ctx(inst);
 656         alg = crypto_spawn_aead_alg(spawn);
 657
 658         inst->alg.setkey = seqiv_aead_setkey;
 659         inst->alg.setauthsize = seqiv_aead_setauthsize;
 660         inst->alg.encrypt = seqiv_aead_encrypt_first;
 661         inst->alg.decrypt = seqiv_aead_decrypt;
 662
 663         inst->alg.base.cra_init = seqiv_aead_init;
 664         inst->alg.base.cra_exit = seqiv_aead_exit;
 665
 666         inst->alg.base.cra_ctxsize = sizeof(struct seqiv_aead_ctx);
 667         inst->alg.base.cra_ctxsize += inst->alg.base.cra_aead.ivsize;
 668
 669         if (alg->base.cra_aead.encrypt) {
 670                 inst->alg.encrypt = seqiv_aead_encrypt_compat_first;
 671                 inst->alg.decrypt = seqiv_aead_decrypt_compat;
 672
 673                 inst->alg.base.cra_init = seqiv_aead_compat_init;
 674                 inst->alg.base.cra_exit = seqiv_aead_compat_exit;
 675         }
 676
 677 out:
 678         return aead_crypto_instance(inst);
 679 }
 680
 681 static struct crypto_instance *seqiv_alloc(struct rtattr **tb)
 682 {
 683         struct crypto_attr_type *algt;
 684         struct crypto_instance *inst;
 685         int err;
 686
 687         algt = crypto_get_attr_type(tb);
 688         if (IS_ERR(algt))
 689                 return ERR_CAST(algt);
 690
 691         err = crypto_get_default_rng();
 692         if (err)
 693                 return ERR_PTR(err);
 694
 695         if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & CRYPTO_ALG_TYPE_MASK)
 696                 inst = seqiv_ablkcipher_alloc(tb);
 697         else
 698                 inst = seqiv_aead_alloc(tb);
 699
 700         if (IS_ERR(inst))
 701                 goto put_rng;
 702
 703         inst->alg.cra_alignmask |= __alignof__(u32) - 1;
 704
 705 out:
 706         return inst;
 707
 708 put_rng:
 709         crypto_put_default_rng();
 710         goto out;
 711 }
 712
 713 static void seqiv_free(struct crypto_instance *inst)
 714 {
 715         if ((inst->alg.cra_flags ^ CRYPTO_ALG_TYPE_AEAD) & CRYPTO_ALG_TYPE_MASK)
 716                 skcipher_geniv_free(inst);
 717         else
 718                 aead_geniv_free(aead_instance(inst));
 719         crypto_put_default_rng();
 720 }
 721
 722 static struct crypto_template seqiv_tmpl = {
 723         .name = "seqiv",
 724         .alloc = seqiv_alloc,
 725         .free = seqiv_free,
 726         .module = THIS_MODULE,
 727 };
 728
 729 static int __init seqiv_module_init(void)
 730 {
 731         return crypto_register_template(&seqiv_tmpl);
 732 }
 733
 734 static void __exit seqiv_module_exit(void)
 735 {
 736         crypto_unregister_template(&seqiv_tmpl);
 737 }
 738
 739 module_init(seqiv_module_init);
 740 module_exit(seqiv_module_exit);
 741
 742 MODULE_LICENSE("GPL");
 743 MODULE_DESCRIPTION("Sequence Number IV Generator");
 744 MODULE_ALIAS_CRYPTO("seqiv");