crypto/authenc.c

   1 /*
   2  * Authenc: Simple AEAD wrapper for IPsec
   3  *
   4  * Copyright (c) 2007 Herbert Xu <herbert@gondor.apana.org.au>
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License as published by the Free
   8  * Software Foundation; either version 2 of the License, or (at your option)
   9  * any later version.
  10  *
  11  */
  12
  13 #include <crypto/aead.h>
  14 #include <crypto/internal/hash.h>
  15 #include <crypto/internal/skcipher.h>
  16 #include <crypto/authenc.h>
  17 #include <crypto/scatterwalk.h>
  18 #include <linux/err.h>
  19 #include <linux/init.h>
  20 #include <linux/kernel.h>
  21 #include <linux/module.h>
  22 #include <linux/rtnetlink.h>
  23 #include <linux/slab.h>
  24 #include <linux/spinlock.h>
  25
  26 typedef u8 *(*authenc_ahash_t)(struct aead_request *req, unsigned int flags);
  27
  28 struct authenc_instance_ctx {
  29         struct crypto_ahash_spawn auth;
  30         struct crypto_skcipher_spawn enc;
  31 };
  32
  33 struct crypto_authenc_ctx {
  34         unsigned int reqoff;
  35         struct crypto_ahash *auth;
  36         struct crypto_ablkcipher *enc;
  37 };
  38
  39 struct authenc_request_ctx {
  40         unsigned int cryptlen;
  41         struct scatterlist *sg;
  42         struct scatterlist asg[2];
  43         struct scatterlist cipher[2];
  44         crypto_completion_t complete;
  45         crypto_completion_t update_complete;
  46         char tail[];
  47 };
  48
  49 static void authenc_request_complete(struct aead_request *req, int err)
  50 {
  51         if (err != -EINPROGRESS)
  52                 aead_request_complete(req, err);
  53 }
  54
  55 static int crypto_authenc_setkey(struct crypto_aead *authenc, const u8 *key,
  56                                  unsigned int keylen)
  57 {
  58         unsigned int authkeylen;
  59         unsigned int enckeylen;
  60         struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
  61         struct crypto_ahash *auth = ctx->auth;
  62         struct crypto_ablkcipher *enc = ctx->enc;
  63         struct rtattr *rta = (void *)key;
  64         struct crypto_authenc_key_param *param;
  65         int err = -EINVAL;
  66
  67         if (!RTA_OK(rta, keylen))
  68                 goto badkey;
  69         if (rta->rta_type != CRYPTO_AUTHENC_KEYA_PARAM)
  70                 goto badkey;
  71         if (RTA_PAYLOAD(rta) < sizeof(*param))
  72                 goto badkey;
  73
  74         param = RTA_DATA(rta);
  75         enckeylen = be32_to_cpu(param->enckeylen);
  76
  77         key += RTA_ALIGN(rta->rta_len);
  78         keylen -= RTA_ALIGN(rta->rta_len);
  79
  80         if (keylen < enckeylen)
  81                 goto badkey;
  82
  83         authkeylen = keylen - enckeylen;
  84
  85         crypto_ahash_clear_flags(auth, CRYPTO_TFM_REQ_MASK);
  86         crypto_ahash_set_flags(auth, crypto_aead_get_flags(authenc) &
  87                                     CRYPTO_TFM_REQ_MASK);
  88         err = crypto_ahash_setkey(auth, key, authkeylen);
  89         crypto_aead_set_flags(authenc, crypto_ahash_get_flags(auth) &
  90                                        CRYPTO_TFM_RES_MASK);
  91
  92         if (err)
  93                 goto out;
  94
  95         crypto_ablkcipher_clear_flags(enc, CRYPTO_TFM_REQ_MASK);
  96         crypto_ablkcipher_set_flags(enc, crypto_aead_get_flags(authenc) &
  97                                          CRYPTO_TFM_REQ_MASK);
  98         err = crypto_ablkcipher_setkey(enc, key + authkeylen, enckeylen);
  99         crypto_aead_set_flags(authenc, crypto_ablkcipher_get_flags(enc) &
 100                                        CRYPTO_TFM_RES_MASK);
 101
 102 out:
 103         return err;
 104
 105 badkey:
 106         crypto_aead_set_flags(authenc, CRYPTO_TFM_RES_BAD_KEY_LEN);
 107         goto out;
 108 }
 109
 110 static void authenc_geniv_ahash_update_done(struct crypto_async_request *areq,
 111                                             int err)
 112 {
 113         struct aead_request *req = areq->data;
 114         struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 115         struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
 116         struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
 117         struct ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
 118
 119         if (err)
 120                 goto out;
 121
 122         ahash_request_set_crypt(ahreq, areq_ctx->sg, ahreq->result,
 123                                 areq_ctx->cryptlen);
 124         ahash_request_set_callback(ahreq, aead_request_flags(req) &
 125                                           CRYPTO_TFM_REQ_MAY_SLEEP,
 126                                    areq_ctx->complete, req);
 127
 128         err = crypto_ahash_finup(ahreq);
 129         if (err)
 130                 goto out;
 131
 132         scatterwalk_map_and_copy(ahreq->result, areq_ctx->sg,
 133                                  areq_ctx->cryptlen,
 134                                  crypto_aead_authsize(authenc), 1);
 135
 136 out:
 137         authenc_request_complete(req, err);
 138 }
 139
 140 static void authenc_geniv_ahash_done(struct crypto_async_request *areq, int err)
 141 {
 142         struct aead_request *req = areq->data;
 143         struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 144         struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
 145         struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
 146         struct ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
 147
 148         if (err)
 149                 goto out;
 150
 151         scatterwalk_map_and_copy(ahreq->result, areq_ctx->sg,
 152                                  areq_ctx->cryptlen,
 153                                  crypto_aead_authsize(authenc), 1);
 154
 155 out:
 156         aead_request_complete(req, err);
 157 }
 158
 159 static void authenc_verify_ahash_update_done(struct crypto_async_request *areq,
 160                                              int err)
 161 {
 162         u8 *ihash;
 163         unsigned int authsize;
 164         struct ablkcipher_request *abreq;
 165         struct aead_request *req = areq->data;
 166         struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 167         struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
 168         struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
 169         struct ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
 170         unsigned int cryptlen = req->cryptlen;
 171
 172         if (err)
 173                 goto out;
 174
 175         ahash_request_set_crypt(ahreq, areq_ctx->sg, ahreq->result,
 176                                 areq_ctx->cryptlen);
 177         ahash_request_set_callback(ahreq, aead_request_flags(req) &
 178                                           CRYPTO_TFM_REQ_MAY_SLEEP,
 179                                    areq_ctx->complete, req);
 180
 181         err = crypto_ahash_finup(ahreq);
 182         if (err)
 183                 goto out;
 184
 185         authsize = crypto_aead_authsize(authenc);
 186         cryptlen -= authsize;
 187         ihash = ahreq->result + authsize;
 188         scatterwalk_map_and_copy(ihash, areq_ctx->sg, areq_ctx->cryptlen,
 189                                  authsize, 0);
 190
 191         err = memcmp(ihash, ahreq->result, authsize) ? -EBADMSG : 0;
 192         if (err)
 193                 goto out;
 194
 195         abreq = aead_request_ctx(req);
 196         ablkcipher_request_set_tfm(abreq, ctx->enc);
 197         ablkcipher_request_set_callback(abreq, aead_request_flags(req),
 198                                         req->base.complete, req->base.data);
 199         ablkcipher_request_set_crypt(abreq, req->src, req->dst,
 200                                      cryptlen, req->iv);
 201
 202         err = crypto_ablkcipher_decrypt(abreq);
 203
 204 out:
 205         authenc_request_complete(req, err);
 206 }
 207
 208 static void authenc_verify_ahash_done(struct crypto_async_request *areq,
 209                                       int err)
 210 {
 211         u8 *ihash;
 212         unsigned int authsize;
 213         struct ablkcipher_request *abreq;
 214         struct aead_request *req = areq->data;
 215         struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 216         struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
 217         struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
 218         struct ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
 219         unsigned int cryptlen = req->cryptlen;
 220
 221         if (err)
 222                 goto out;
 223
 224         authsize = crypto_aead_authsize(authenc);
 225         cryptlen -= authsize;
 226         ihash = ahreq->result + authsize;
 227         scatterwalk_map_and_copy(ihash, areq_ctx->sg, areq_ctx->cryptlen,
 228                                  authsize, 0);
 229
 230         err = memcmp(ihash, ahreq->result, authsize) ? -EBADMSG : 0;
 231         if (err)
 232                 goto out;
 233
 234         abreq = aead_request_ctx(req);
 235         ablkcipher_request_set_tfm(abreq, ctx->enc);
 236         ablkcipher_request_set_callback(abreq, aead_request_flags(req),
 237                                         req->base.complete, req->base.data);
 238         ablkcipher_request_set_crypt(abreq, req->src, req->dst,
 239                                      cryptlen, req->iv);
 240
 241         err = crypto_ablkcipher_decrypt(abreq);
 242
 243 out:
 244         authenc_request_complete(req, err);
 245 }
 246
 247 static u8 *crypto_authenc_ahash_fb(struct aead_request *req, unsigned int flags)
 248 {
 249         struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 250         struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
 251         struct crypto_ahash *auth = ctx->auth;
 252         struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
 253         struct ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
 254         u8 *hash = areq_ctx->tail;
 255         int err;
 256
 257         hash = (u8 *)ALIGN((unsigned long)hash + crypto_ahash_alignmask(auth),
 258                             crypto_ahash_alignmask(auth) + 1);
 259
 260         ahash_request_set_tfm(ahreq, auth);
 261
 262         err = crypto_ahash_init(ahreq);
 263         if (err)
 264                 return ERR_PTR(err);
 265
 266         ahash_request_set_crypt(ahreq, req->assoc, hash, req->assoclen);
 267         ahash_request_set_callback(ahreq, aead_request_flags(req) & flags,
 268                                    areq_ctx->update_complete, req);
 269
 270         err = crypto_ahash_update(ahreq);
 271         if (err)
 272                 return ERR_PTR(err);
 273
 274         ahash_request_set_crypt(ahreq, areq_ctx->sg, hash,
 275                                 areq_ctx->cryptlen);
 276         ahash_request_set_callback(ahreq, aead_request_flags(req) & flags,
 277                                    areq_ctx->complete, req);
 278
 279         err = crypto_ahash_finup(ahreq);
 280         if (err)
 281                 return ERR_PTR(err);
 282
 283         return hash;
 284 }
 285
 286 static u8 *crypto_authenc_ahash(struct aead_request *req, unsigned int flags)
 287 {
 288         struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 289         struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
 290         struct crypto_ahash *auth = ctx->auth;
 291         struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
 292         struct ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
 293         u8 *hash = areq_ctx->tail;
 294         int err;
 295
 296         hash = (u8 *)ALIGN((unsigned long)hash + crypto_ahash_alignmask(auth),
 297                            crypto_ahash_alignmask(auth) + 1);
 298
 299         ahash_request_set_tfm(ahreq, auth);
 300         ahash_request_set_crypt(ahreq, areq_ctx->sg, hash,
 301                                 areq_ctx->cryptlen);
 302         ahash_request_set_callback(ahreq, aead_request_flags(req) & flags,
 303                                    areq_ctx->complete, req);
 304
 305         err = crypto_ahash_digest(ahreq);
 306         if (err)
 307                 return ERR_PTR(err);
 308
 309         return hash;
 310 }
 311
 312 static int crypto_authenc_genicv(struct aead_request *req, u8 *iv,
 313                                  unsigned int flags)
 314 {
 315         struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 316         struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
 317         struct scatterlist *dst = req->dst;
 318         struct scatterlist *assoc = req->assoc;
 319         struct scatterlist *cipher = areq_ctx->cipher;
 320         struct scatterlist *asg = areq_ctx->asg;
 321         unsigned int ivsize = crypto_aead_ivsize(authenc);
 322         unsigned int cryptlen = req->cryptlen;
 323         authenc_ahash_t authenc_ahash_fn = crypto_authenc_ahash_fb;
 324         struct page *dstp;
 325         u8 *vdst;
 326         u8 *hash;
 327
 328         dstp = sg_page(dst);
 329         vdst = PageHighMem(dstp) ? NULL : page_address(dstp) + dst->offset;
 330
 331         if (ivsize) {
 332                 sg_init_table(cipher, 2);
 333                 sg_set_buf(cipher, iv, ivsize);
 334                 scatterwalk_crypto_chain(cipher, dst, vdst == iv + ivsize, 2);
 335                 dst = cipher;
 336                 cryptlen += ivsize;
 337         }
 338
 339         if (req->assoclen && sg_is_last(assoc)) {
 340                 authenc_ahash_fn = crypto_authenc_ahash;
 341                 sg_init_table(asg, 2);
 342                 sg_set_page(asg, sg_page(assoc), assoc->length, assoc->offset);
 343                 scatterwalk_crypto_chain(asg, dst, 0, 2);
 344                 dst = asg;
 345                 cryptlen += req->assoclen;
 346         }
 347
 348         areq_ctx->cryptlen = cryptlen;
 349         areq_ctx->sg = dst;
 350
 351         areq_ctx->complete = authenc_geniv_ahash_done;
 352         areq_ctx->update_complete = authenc_geniv_ahash_update_done;
 353
 354         hash = authenc_ahash_fn(req, flags);
 355         if (IS_ERR(hash))
 356                 return PTR_ERR(hash);
 357
 358         scatterwalk_map_and_copy(hash, dst, cryptlen,
 359                                  crypto_aead_authsize(authenc), 1);
 360         return 0;
 361 }
 362
 363 static void crypto_authenc_encrypt_done(struct crypto_async_request *req,
 364                                         int err)
 365 {
 366         struct aead_request *areq = req->data;
 367
 368         if (!err) {
 369                 struct crypto_aead *authenc = crypto_aead_reqtfm(areq);
 370                 struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
 371                 struct ablkcipher_request *abreq = aead_request_ctx(areq);
 372                 u8 *iv = (u8 *)(abreq + 1) +
 373                          crypto_ablkcipher_reqsize(ctx->enc);
 374
 375                 err = crypto_authenc_genicv(areq, iv, 0);
 376         }
 377
 378         authenc_request_complete(areq, err);
 379 }
 380
 381 static int crypto_authenc_encrypt(struct aead_request *req)
 382 {
 383         struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 384         struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
 385         struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
 386         struct crypto_ablkcipher *enc = ctx->enc;
 387         struct scatterlist *dst = req->dst;
 388         unsigned int cryptlen = req->cryptlen;
 389         struct ablkcipher_request *abreq = (void *)(areq_ctx->tail
 390                                                     + ctx->reqoff);
 391         u8 *iv = (u8 *)abreq - crypto_ablkcipher_ivsize(enc);
 392         int err;
 393
 394         ablkcipher_request_set_tfm(abreq, enc);
 395         ablkcipher_request_set_callback(abreq, aead_request_flags(req),
 396                                         crypto_authenc_encrypt_done, req);
 397         ablkcipher_request_set_crypt(abreq, req->src, dst, cryptlen, req->iv);
 398
 399         memcpy(iv, req->iv, crypto_aead_ivsize(authenc));
 400
 401         err = crypto_ablkcipher_encrypt(abreq);
 402         if (err)
 403                 return err;
 404
 405         return crypto_authenc_genicv(req, iv, CRYPTO_TFM_REQ_MAY_SLEEP);
 406 }
 407
 408 static void crypto_authenc_givencrypt_done(struct crypto_async_request *req,
 409                                            int err)
 410 {
 411         struct aead_request *areq = req->data;
 412
 413         if (!err) {
 414                 struct skcipher_givcrypt_request *greq = aead_request_ctx(areq);
 415
 416                 err = crypto_authenc_genicv(areq, greq->giv, 0);
 417         }
 418
 419         authenc_request_complete(areq, err);
 420 }
 421
 422 static int crypto_authenc_givencrypt(struct aead_givcrypt_request *req)
 423 {
 424         struct crypto_aead *authenc = aead_givcrypt_reqtfm(req);
 425         struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
 426         struct aead_request *areq = &req->areq;
 427         struct skcipher_givcrypt_request *greq = aead_request_ctx(areq);
 428         u8 *iv = req->giv;
 429         int err;
 430
 431         skcipher_givcrypt_set_tfm(greq, ctx->enc);
 432         skcipher_givcrypt_set_callback(greq, aead_request_flags(areq),
 433                                        crypto_authenc_givencrypt_done, areq);
 434         skcipher_givcrypt_set_crypt(greq, areq->src, areq->dst, areq->cryptlen,
 435                                     areq->iv);
 436         skcipher_givcrypt_set_giv(greq, iv, req->seq);
 437
 438         err = crypto_skcipher_givencrypt(greq);
 439         if (err)
 440                 return err;
 441
 442         return crypto_authenc_genicv(areq, iv, CRYPTO_TFM_REQ_MAY_SLEEP);
 443 }
 444
 445 static int crypto_authenc_verify(struct aead_request *req,
 446                                  authenc_ahash_t authenc_ahash_fn)
 447 {
 448         struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 449         struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
 450         u8 *ohash;
 451         u8 *ihash;
 452         unsigned int authsize;
 453
 454         areq_ctx->complete = authenc_verify_ahash_done;
 455         areq_ctx->update_complete = authenc_verify_ahash_update_done;
 456
 457         ohash = authenc_ahash_fn(req, CRYPTO_TFM_REQ_MAY_SLEEP);
 458         if (IS_ERR(ohash))
 459                 return PTR_ERR(ohash);
 460
 461         authsize = crypto_aead_authsize(authenc);
 462         ihash = ohash + authsize;
 463         scatterwalk_map_and_copy(ihash, areq_ctx->sg, areq_ctx->cryptlen,
 464                                  authsize, 0);
 465         return memcmp(ihash, ohash, authsize) ? -EBADMSG : 0;
 466 }
 467
 468 static int crypto_authenc_iverify(struct aead_request *req, u8 *iv,
 469                                   unsigned int cryptlen)
 470 {
 471         struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 472         struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
 473         struct scatterlist *src = req->src;
 474         struct scatterlist *assoc = req->assoc;
 475         struct scatterlist *cipher = areq_ctx->cipher;
 476         struct scatterlist *asg = areq_ctx->asg;
 477         unsigned int ivsize = crypto_aead_ivsize(authenc);
 478         authenc_ahash_t authenc_ahash_fn = crypto_authenc_ahash_fb;
 479         struct page *srcp;
 480         u8 *vsrc;
 481
 482         srcp = sg_page(src);
 483         vsrc = PageHighMem(srcp) ? NULL : page_address(srcp) + src->offset;
 484
 485         if (ivsize) {
 486                 sg_init_table(cipher, 2);
 487                 sg_set_buf(cipher, iv, ivsize);
 488                 scatterwalk_crypto_chain(cipher, src, vsrc == iv + ivsize, 2);
 489                 src = cipher;
 490                 cryptlen += ivsize;
 491         }
 492
 493         if (req->assoclen && sg_is_last(assoc)) {
 494                 authenc_ahash_fn = crypto_authenc_ahash;
 495                 sg_init_table(asg, 2);
 496                 sg_set_page(asg, sg_page(assoc), assoc->length, assoc->offset);
 497                 scatterwalk_crypto_chain(asg, src, 0, 2);
 498                 src = asg;
 499                 cryptlen += req->assoclen;
 500         }
 501
 502         areq_ctx->cryptlen = cryptlen;
 503         areq_ctx->sg = src;
 504
 505         return crypto_authenc_verify(req, authenc_ahash_fn);
 506 }
 507
 508 static int crypto_authenc_decrypt(struct aead_request *req)
 509 {
 510         struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 511         struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
 512         struct ablkcipher_request *abreq = aead_request_ctx(req);
 513         unsigned int cryptlen = req->cryptlen;
 514         unsigned int authsize = crypto_aead_authsize(authenc);
 515         u8 *iv = req->iv;
 516         int err;
 517
 518         if (cryptlen < authsize)
 519                 return -EINVAL;
 520         cryptlen -= authsize;
 521
 522         err = crypto_authenc_iverify(req, iv, cryptlen);
 523         if (err)
 524                 return err;
 525
 526         ablkcipher_request_set_tfm(abreq, ctx->enc);
 527         ablkcipher_request_set_callback(abreq, aead_request_flags(req),
 528                                         req->base.complete, req->base.data);
 529         ablkcipher_request_set_crypt(abreq, req->src, req->dst, cryptlen, iv);
 530
 531         return crypto_ablkcipher_decrypt(abreq);
 532 }
 533
 534 static int crypto_authenc_init_tfm(struct crypto_tfm *tfm)
 535 {
 536         struct crypto_instance *inst = crypto_tfm_alg_instance(tfm);
 537         struct authenc_instance_ctx *ictx = crypto_instance_ctx(inst);
 538         struct crypto_authenc_ctx *ctx = crypto_tfm_ctx(tfm);
 539         struct crypto_ahash *auth;
 540         struct crypto_ablkcipher *enc;
 541         int err;
 542
 543         auth = crypto_spawn_ahash(&ictx->auth);
 544         if (IS_ERR(auth))
 545                 return PTR_ERR(auth);
 546
 547         enc = crypto_spawn_skcipher(&ictx->enc);
 548         err = PTR_ERR(enc);
 549         if (IS_ERR(enc))
 550                 goto err_free_ahash;
 551
 552         ctx->auth = auth;
 553         ctx->enc = enc;
 554
 555         ctx->reqoff = ALIGN(2 * crypto_ahash_digestsize(auth) +
 556                             crypto_ahash_alignmask(auth),
 557                             crypto_ahash_alignmask(auth) + 1) +
 558                       crypto_ablkcipher_ivsize(enc);
 559
 560         tfm->crt_aead.reqsize = sizeof(struct authenc_request_ctx) +
 561                                 ctx->reqoff +
 562                                 max_t(unsigned int,
 563                                 crypto_ahash_reqsize(auth) +
 564                                 sizeof(struct ahash_request),
 565                                 sizeof(struct skcipher_givcrypt_request) +
 566                                 crypto_ablkcipher_reqsize(enc));
 567
 568         return 0;
 569
 570 err_free_ahash:
 571         crypto_free_ahash(auth);
 572         return err;
 573 }
 574
 575 static void crypto_authenc_exit_tfm(struct crypto_tfm *tfm)
 576 {
 577         struct crypto_authenc_ctx *ctx = crypto_tfm_ctx(tfm);
 578
 579         crypto_free_ahash(ctx->auth);
 580         crypto_free_ablkcipher(ctx->enc);
 581 }
 582
 583 static struct crypto_instance *crypto_authenc_alloc(struct rtattr **tb)
 584 {
 585         struct crypto_attr_type *algt;
 586         struct crypto_instance *inst;
 587         struct hash_alg_common *auth;
 588         struct crypto_alg *auth_base;
 589         struct crypto_alg *enc;
 590         struct authenc_instance_ctx *ctx;
 591         const char *enc_name;
 592         int err;
 593
 594         algt = crypto_get_attr_type(tb);
 595         if (IS_ERR(algt))
 596                 return ERR_CAST(algt);
 597
 598         if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
 599                 return ERR_PTR(-EINVAL);
 600
 601         auth = ahash_attr_alg(tb[1], CRYPTO_ALG_TYPE_HASH,
 602                                CRYPTO_ALG_TYPE_AHASH_MASK);
 603         if (IS_ERR(auth))
 604                 return ERR_CAST(auth);
 605
 606         auth_base = &auth->base;
 607
 608         enc_name = crypto_attr_alg_name(tb[2]);
 609         err = PTR_ERR(enc_name);
 610         if (IS_ERR(enc_name))
 611                 goto out_put_auth;
 612
 613         inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
 614         err = -ENOMEM;
 615         if (!inst)
 616                 goto out_put_auth;
 617
 618         ctx = crypto_instance_ctx(inst);
 619
 620         err = crypto_init_ahash_spawn(&ctx->auth, auth, inst);
 621         if (err)
 622                 goto err_free_inst;
 623
 624         crypto_set_skcipher_spawn(&ctx->enc, inst);
 625         err = crypto_grab_skcipher(&ctx->enc, enc_name, 0,
 626                                    crypto_requires_sync(algt->type,
 627                                                         algt->mask));
 628         if (err)
 629                 goto err_drop_auth;
 630
 631         enc = crypto_skcipher_spawn_alg(&ctx->enc);
 632
 633         err = -ENAMETOOLONG;
 634         if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME,
 635                      "authenc(%s,%s)", auth_base->cra_name, enc->cra_name) >=
 636             CRYPTO_MAX_ALG_NAME)
 637                 goto err_drop_enc;
 638
 639         if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
 640                      "authenc(%s,%s)", auth_base->cra_driver_name,
 641                      enc->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
 642                 goto err_drop_enc;
 643
 644         inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD;
 645         inst->alg.cra_flags |= enc->cra_flags & CRYPTO_ALG_ASYNC;
 646         inst->alg.cra_priority = enc->cra_priority *
 647                                  10 + auth_base->cra_priority;
 648         inst->alg.cra_blocksize = enc->cra_blocksize;
 649         inst->alg.cra_alignmask = auth_base->cra_alignmask | enc->cra_alignmask;
 650         inst->alg.cra_type = &crypto_aead_type;
 651
 652         inst->alg.cra_aead.ivsize = enc->cra_ablkcipher.ivsize;
 653         inst->alg.cra_aead.maxauthsize = auth->digestsize;
 654
 655         inst->alg.cra_ctxsize = sizeof(struct crypto_authenc_ctx);
 656
 657         inst->alg.cra_init = crypto_authenc_init_tfm;
 658         inst->alg.cra_exit = crypto_authenc_exit_tfm;
 659
 660         inst->alg.cra_aead.setkey = crypto_authenc_setkey;
 661         inst->alg.cra_aead.encrypt = crypto_authenc_encrypt;
 662         inst->alg.cra_aead.decrypt = crypto_authenc_decrypt;
 663         inst->alg.cra_aead.givencrypt = crypto_authenc_givencrypt;
 664
 665 out:
 666         crypto_mod_put(auth_base);
 667         return inst;
 668
 669 err_drop_enc:
 670         crypto_drop_skcipher(&ctx->enc);
 671 err_drop_auth:
 672         crypto_drop_ahash(&ctx->auth);
 673 err_free_inst:
 674         kfree(inst);
 675 out_put_auth:
 676         inst = ERR_PTR(err);
 677         goto out;
 678 }
 679
 680 static void crypto_authenc_free(struct crypto_instance *inst)
 681 {
 682         struct authenc_instance_ctx *ctx = crypto_instance_ctx(inst);
 683
 684         crypto_drop_skcipher(&ctx->enc);
 685         crypto_drop_ahash(&ctx->auth);
 686         kfree(inst);
 687 }
 688
 689 static struct crypto_template crypto_authenc_tmpl = {
 690         .name = "authenc",
 691         .alloc = crypto_authenc_alloc,
 692         .free = crypto_authenc_free,
 693         .module = THIS_MODULE,
 694 };
 695
 696 static int __init crypto_authenc_module_init(void)
 697 {
 698         return crypto_register_template(&crypto_authenc_tmpl);
 699 }
 700
 701 static void __exit crypto_authenc_module_exit(void)
 702 {
 703         crypto_unregister_template(&crypto_authenc_tmpl);
 704 }
 705
 706 module_init(crypto_authenc_module_init);
 707 module_exit(crypto_authenc_module_exit);
 708
 709 MODULE_LICENSE("GPL");
 710 MODULE_DESCRIPTION("Simple AEAD wrapper for IPsec");