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_chain(struct scatterlist *head, struct scatterlist *sg,
 111                           int chain)
 112 {
 113         if (chain) {
 114                 head->length += sg->length;
 115                 sg = scatterwalk_sg_next(sg);
 116         }
 117
 118         if (sg)
 119                 scatterwalk_sg_chain(head, 2, sg);
 120         else
 121                 sg_mark_end(head);
 122 }
 123
 124 static void authenc_geniv_ahash_update_done(struct crypto_async_request *areq,
 125                                             int err)
 126 {
 127         struct aead_request *req = areq->data;
 128         struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 129         struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
 130         struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
 131         struct ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
 132
 133         if (err)
 134                 goto out;
 135
 136         ahash_request_set_crypt(ahreq, areq_ctx->sg, ahreq->result,
 137                                 areq_ctx->cryptlen);
 138         ahash_request_set_callback(ahreq, aead_request_flags(req) &
 139                                           CRYPTO_TFM_REQ_MAY_SLEEP,
 140                                    areq_ctx->complete, req);
 141
 142         err = crypto_ahash_finup(ahreq);
 143         if (err)
 144                 goto out;
 145
 146         scatterwalk_map_and_copy(ahreq->result, areq_ctx->sg,
 147                                  areq_ctx->cryptlen,
 148                                  crypto_aead_authsize(authenc), 1);
 149
 150 out:
 151         authenc_request_complete(req, err);
 152 }
 153
 154 static void authenc_geniv_ahash_done(struct crypto_async_request *areq, int err)
 155 {
 156         struct aead_request *req = areq->data;
 157         struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 158         struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
 159         struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
 160         struct ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
 161
 162         if (err)
 163                 goto out;
 164
 165         scatterwalk_map_and_copy(ahreq->result, areq_ctx->sg,
 166                                  areq_ctx->cryptlen,
 167                                  crypto_aead_authsize(authenc), 1);
 168
 169 out:
 170         aead_request_complete(req, err);
 171 }
 172
 173 static void authenc_verify_ahash_update_done(struct crypto_async_request *areq,
 174                                              int err)
 175 {
 176         u8 *ihash;
 177         unsigned int authsize;
 178         struct ablkcipher_request *abreq;
 179         struct aead_request *req = areq->data;
 180         struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 181         struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
 182         struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
 183         struct ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
 184
 185         if (err)
 186                 goto out;
 187
 188         ahash_request_set_crypt(ahreq, areq_ctx->sg, ahreq->result,
 189                                 areq_ctx->cryptlen);
 190         ahash_request_set_callback(ahreq, aead_request_flags(req) &
 191                                           CRYPTO_TFM_REQ_MAY_SLEEP,
 192                                    areq_ctx->complete, req);
 193
 194         err = crypto_ahash_finup(ahreq);
 195         if (err)
 196                 goto out;
 197
 198         authsize = crypto_aead_authsize(authenc);
 199         ihash = ahreq->result + authsize;
 200         scatterwalk_map_and_copy(ihash, areq_ctx->sg, areq_ctx->cryptlen,
 201                                  authsize, 0);
 202
 203         err = memcmp(ihash, ahreq->result, authsize) ? -EBADMSG: 0;
 204         if (err)
 205                 goto out;
 206
 207         abreq = aead_request_ctx(req);
 208         ablkcipher_request_set_tfm(abreq, ctx->enc);
 209         ablkcipher_request_set_callback(abreq, aead_request_flags(req),
 210                                         req->base.complete, req->base.data);
 211         ablkcipher_request_set_crypt(abreq, req->src, req->dst,
 212                                      req->cryptlen, req->iv);
 213
 214         err = crypto_ablkcipher_decrypt(abreq);
 215
 216 out:
 217         authenc_request_complete(req, err);
 218 }
 219
 220 static void authenc_verify_ahash_done(struct crypto_async_request *areq,
 221                                       int err)
 222 {
 223         u8 *ihash;
 224         unsigned int authsize;
 225         struct ablkcipher_request *abreq;
 226         struct aead_request *req = areq->data;
 227         struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 228         struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
 229         struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
 230         struct ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
 231
 232         if (err)
 233                 goto out;
 234
 235         authsize = crypto_aead_authsize(authenc);
 236         ihash = ahreq->result + authsize;
 237         scatterwalk_map_and_copy(ihash, areq_ctx->sg, areq_ctx->cryptlen,
 238                                  authsize, 0);
 239
 240         err = memcmp(ihash, ahreq->result, authsize) ? -EBADMSG: 0;
 241         if (err)
 242                 goto out;
 243
 244         abreq = aead_request_ctx(req);
 245         ablkcipher_request_set_tfm(abreq, ctx->enc);
 246         ablkcipher_request_set_callback(abreq, aead_request_flags(req),
 247                                         req->base.complete, req->base.data);
 248         ablkcipher_request_set_crypt(abreq, req->src, req->dst,
 249                                      req->cryptlen, req->iv);
 250
 251         err = crypto_ablkcipher_decrypt(abreq);
 252
 253 out:
 254         authenc_request_complete(req, err);
 255 }
 256
 257 static u8 *crypto_authenc_ahash_fb(struct aead_request *req, unsigned int flags)
 258 {
 259         struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 260         struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
 261         struct crypto_ahash *auth = ctx->auth;
 262         struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
 263         struct ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
 264         u8 *hash = areq_ctx->tail;
 265         int err;
 266
 267         hash = (u8 *)ALIGN((unsigned long)hash + crypto_ahash_alignmask(auth),
 268                             crypto_ahash_alignmask(auth) + 1);
 269
 270         ahash_request_set_tfm(ahreq, auth);
 271
 272         err = crypto_ahash_init(ahreq);
 273         if (err)
 274                 return ERR_PTR(err);
 275
 276         ahash_request_set_crypt(ahreq, req->assoc, hash, req->assoclen);
 277         ahash_request_set_callback(ahreq, aead_request_flags(req) & flags,
 278                                    areq_ctx->update_complete, req);
 279
 280         err = crypto_ahash_update(ahreq);
 281         if (err)
 282                 return ERR_PTR(err);
 283
 284         ahash_request_set_crypt(ahreq, areq_ctx->sg, hash,
 285                                 areq_ctx->cryptlen);
 286         ahash_request_set_callback(ahreq, aead_request_flags(req) & flags,
 287                                    areq_ctx->complete, req);
 288
 289         err = crypto_ahash_finup(ahreq);
 290         if (err)
 291                 return ERR_PTR(err);
 292
 293         return hash;
 294 }
 295
 296 static u8 *crypto_authenc_ahash(struct aead_request *req, unsigned int flags)
 297 {
 298         struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 299         struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
 300         struct crypto_ahash *auth = ctx->auth;
 301         struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
 302         struct ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
 303         u8 *hash = areq_ctx->tail;
 304         int err;
 305
 306         hash = (u8 *)ALIGN((unsigned long)hash + crypto_ahash_alignmask(auth),
 307                            crypto_ahash_alignmask(auth) + 1);
 308
 309         ahash_request_set_tfm(ahreq, auth);
 310         ahash_request_set_crypt(ahreq, areq_ctx->sg, hash,
 311                                 areq_ctx->cryptlen);
 312         ahash_request_set_callback(ahreq, aead_request_flags(req) & flags,
 313                                    areq_ctx->complete, req);
 314
 315         err = crypto_ahash_digest(ahreq);
 316         if (err)
 317                 return ERR_PTR(err);
 318
 319         return hash;
 320 }
 321
 322 static int crypto_authenc_genicv(struct aead_request *req, u8 *iv,
 323                                  unsigned int flags)
 324 {
 325         struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 326         struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
 327         struct scatterlist *dst = req->dst;
 328         struct scatterlist *assoc = req->assoc;
 329         struct scatterlist *cipher = areq_ctx->cipher;
 330         struct scatterlist *asg = areq_ctx->asg;
 331         unsigned int ivsize = crypto_aead_ivsize(authenc);
 332         unsigned int cryptlen = req->cryptlen;
 333         authenc_ahash_t authenc_ahash_fn = crypto_authenc_ahash_fb;
 334         struct page *dstp;
 335         u8 *vdst;
 336         u8 *hash;
 337
 338         dstp = sg_page(dst);
 339         vdst = PageHighMem(dstp) ? NULL : page_address(dstp) + dst->offset;
 340
 341         if (ivsize) {
 342                 sg_init_table(cipher, 2);
 343                 sg_set_buf(cipher, iv, ivsize);
 344                 authenc_chain(cipher, dst, vdst == iv + ivsize);
 345                 dst = cipher;
 346                 cryptlen += ivsize;
 347         }
 348
 349         if (sg_is_last(assoc)) {
 350                 authenc_ahash_fn = crypto_authenc_ahash;
 351                 sg_init_table(asg, 2);
 352                 sg_set_page(asg, sg_page(assoc), assoc->length, assoc->offset);
 353                 authenc_chain(asg, dst, 0);
 354                 dst = asg;
 355                 cryptlen += req->assoclen;
 356         }
 357
 358         areq_ctx->cryptlen = cryptlen;
 359         areq_ctx->sg = dst;
 360
 361         areq_ctx->complete = authenc_geniv_ahash_done;
 362         areq_ctx->update_complete = authenc_geniv_ahash_update_done;
 363
 364         hash = authenc_ahash_fn(req, flags);
 365         if (IS_ERR(hash))
 366                 return PTR_ERR(hash);
 367
 368         scatterwalk_map_and_copy(hash, dst, cryptlen,
 369                                  crypto_aead_authsize(authenc), 1);
 370         return 0;
 371 }
 372
 373 static void crypto_authenc_encrypt_done(struct crypto_async_request *req,
 374                                         int err)
 375 {
 376         struct aead_request *areq = req->data;
 377
 378         if (!err) {
 379                 struct crypto_aead *authenc = crypto_aead_reqtfm(areq);
 380                 struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
 381                 struct ablkcipher_request *abreq = aead_request_ctx(areq);
 382                 u8 *iv = (u8 *)(abreq + 1) +
 383                          crypto_ablkcipher_reqsize(ctx->enc);
 384
 385                 err = crypto_authenc_genicv(areq, iv, 0);
 386         }
 387
 388         authenc_request_complete(areq, err);
 389 }
 390
 391 static int crypto_authenc_encrypt(struct aead_request *req)
 392 {
 393         struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 394         struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
 395         struct ablkcipher_request *abreq = aead_request_ctx(req);
 396         struct crypto_ablkcipher *enc = ctx->enc;
 397         struct scatterlist *dst = req->dst;
 398         unsigned int cryptlen = req->cryptlen;
 399         u8 *iv = (u8 *)(abreq + 1) + crypto_ablkcipher_reqsize(enc);
 400         int err;
 401
 402         ablkcipher_request_set_tfm(abreq, enc);
 403         ablkcipher_request_set_callback(abreq, aead_request_flags(req),
 404                                         crypto_authenc_encrypt_done, req);
 405         ablkcipher_request_set_crypt(abreq, req->src, dst, cryptlen, req->iv);
 406
 407         memcpy(iv, req->iv, crypto_aead_ivsize(authenc));
 408
 409         err = crypto_ablkcipher_encrypt(abreq);
 410         if (err)
 411                 return err;
 412
 413         return crypto_authenc_genicv(req, iv, CRYPTO_TFM_REQ_MAY_SLEEP);
 414 }
 415
 416 static void crypto_authenc_givencrypt_done(struct crypto_async_request *req,
 417                                            int err)
 418 {
 419         struct aead_request *areq = req->data;
 420
 421         if (!err) {
 422                 struct skcipher_givcrypt_request *greq = aead_request_ctx(areq);
 423
 424                 err = crypto_authenc_genicv(areq, greq->giv, 0);
 425         }
 426
 427         authenc_request_complete(areq, err);
 428 }
 429
 430 static int crypto_authenc_givencrypt(struct aead_givcrypt_request *req)
 431 {
 432         struct crypto_aead *authenc = aead_givcrypt_reqtfm(req);
 433         struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
 434         struct aead_request *areq = &req->areq;
 435         struct skcipher_givcrypt_request *greq = aead_request_ctx(areq);
 436         u8 *iv = req->giv;
 437         int err;
 438
 439         skcipher_givcrypt_set_tfm(greq, ctx->enc);
 440         skcipher_givcrypt_set_callback(greq, aead_request_flags(areq),
 441                                        crypto_authenc_givencrypt_done, areq);
 442         skcipher_givcrypt_set_crypt(greq, areq->src, areq->dst, areq->cryptlen,
 443                                     areq->iv);
 444         skcipher_givcrypt_set_giv(greq, iv, req->seq);
 445
 446         err = crypto_skcipher_givencrypt(greq);
 447         if (err)
 448                 return err;
 449
 450         return crypto_authenc_genicv(areq, iv, CRYPTO_TFM_REQ_MAY_SLEEP);
 451 }
 452
 453 static int crypto_authenc_verify(struct aead_request *req,
 454                                  authenc_ahash_t authenc_ahash_fn)
 455 {
 456         struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 457         struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
 458         u8 *ohash;
 459         u8 *ihash;
 460         unsigned int authsize;
 461
 462         areq_ctx->complete = authenc_verify_ahash_done;
 463         areq_ctx->complete = authenc_verify_ahash_update_done;
 464
 465         ohash = authenc_ahash_fn(req, CRYPTO_TFM_REQ_MAY_SLEEP);
 466         if (IS_ERR(ohash))
 467                 return PTR_ERR(ohash);
 468
 469         authsize = crypto_aead_authsize(authenc);
 470         ihash = ohash + authsize;
 471         scatterwalk_map_and_copy(ihash, areq_ctx->sg, areq_ctx->cryptlen,
 472                                  authsize, 0);
 473         return memcmp(ihash, ohash, authsize) ? -EBADMSG: 0;
 474 }
 475
 476 static int crypto_authenc_iverify(struct aead_request *req, u8 *iv,
 477                                   unsigned int cryptlen)
 478 {
 479         struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 480         struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
 481         struct scatterlist *src = req->src;
 482         struct scatterlist *assoc = req->assoc;
 483         struct scatterlist *cipher = areq_ctx->cipher;
 484         struct scatterlist *asg = areq_ctx->asg;
 485         unsigned int ivsize = crypto_aead_ivsize(authenc);
 486         authenc_ahash_t authenc_ahash_fn = crypto_authenc_ahash_fb;
 487         struct page *srcp;
 488         u8 *vsrc;
 489
 490         srcp = sg_page(src);
 491         vsrc = PageHighMem(srcp) ? NULL : page_address(srcp) + src->offset;
 492
 493         if (ivsize) {
 494                 sg_init_table(cipher, 2);
 495                 sg_set_buf(cipher, iv, ivsize);
 496                 authenc_chain(cipher, src, vsrc == iv + ivsize);
 497                 src = cipher;
 498                 cryptlen += ivsize;
 499         }
 500
 501         if (sg_is_last(assoc)) {
 502                 authenc_ahash_fn = crypto_authenc_ahash;
 503                 sg_init_table(asg, 2);
 504                 sg_set_page(asg, sg_page(assoc), assoc->length, assoc->offset);
 505                 authenc_chain(asg, src, 0);
 506                 src = asg;
 507                 cryptlen += req->assoclen;
 508         }
 509
 510         areq_ctx->cryptlen = cryptlen;
 511         areq_ctx->sg = src;
 512
 513         return crypto_authenc_verify(req, authenc_ahash_fn);
 514 }
 515
 516 static int crypto_authenc_decrypt(struct aead_request *req)
 517 {
 518         struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 519         struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
 520         struct ablkcipher_request *abreq = aead_request_ctx(req);
 521         unsigned int cryptlen = req->cryptlen;
 522         unsigned int authsize = crypto_aead_authsize(authenc);
 523         u8 *iv = req->iv;
 524         int err;
 525
 526         if (cryptlen < authsize)
 527                 return -EINVAL;
 528         cryptlen -= authsize;
 529
 530         err = crypto_authenc_iverify(req, iv, cryptlen);
 531         if (err)
 532                 return err;
 533
 534         ablkcipher_request_set_tfm(abreq, ctx->enc);
 535         ablkcipher_request_set_callback(abreq, aead_request_flags(req),
 536                                         req->base.complete, req->base.data);
 537         ablkcipher_request_set_crypt(abreq, req->src, req->dst, cryptlen, iv);
 538
 539         return crypto_ablkcipher_decrypt(abreq);
 540 }
 541
 542 static int crypto_authenc_init_tfm(struct crypto_tfm *tfm)
 543 {
 544         struct crypto_instance *inst = crypto_tfm_alg_instance(tfm);
 545         struct authenc_instance_ctx *ictx = crypto_instance_ctx(inst);
 546         struct crypto_authenc_ctx *ctx = crypto_tfm_ctx(tfm);
 547         struct crypto_ahash *auth;
 548         struct crypto_ablkcipher *enc;
 549         int err;
 550
 551         auth = crypto_spawn_ahash(&ictx->auth);
 552         if (IS_ERR(auth))
 553                 return PTR_ERR(auth);
 554
 555         ctx->reqoff = ALIGN(2 * crypto_ahash_digestsize(auth) +
 556                             crypto_ahash_alignmask(auth),
 557                             crypto_ahash_alignmask(auth) + 1);
 558
 559         enc = crypto_spawn_skcipher(&ictx->enc);
 560         err = PTR_ERR(enc);
 561         if (IS_ERR(enc))
 562                 goto err_free_ahash;
 563
 564         ctx->auth = auth;
 565         ctx->enc = enc;
 566
 567         tfm->crt_aead.reqsize = max_t(unsigned int,
 568                                 crypto_ahash_reqsize(auth) + ctx->reqoff +
 569                                 sizeof(struct authenc_request_ctx) +
 570                                 sizeof(struct ahash_request),
 571                                 sizeof(struct skcipher_givcrypt_request) +
 572                                 crypto_ablkcipher_reqsize(enc) +
 573                                 crypto_ablkcipher_ivsize(enc));
 574
 575         return 0;
 576
 577 err_free_ahash:
 578         crypto_free_ahash(auth);
 579         return err;
 580 }
 581
 582 static void crypto_authenc_exit_tfm(struct crypto_tfm *tfm)
 583 {
 584         struct crypto_authenc_ctx *ctx = crypto_tfm_ctx(tfm);
 585
 586         crypto_free_ahash(ctx->auth);
 587         crypto_free_ablkcipher(ctx->enc);
 588 }
 589
 590 static struct crypto_instance *crypto_authenc_alloc(struct rtattr **tb)
 591 {
 592         struct crypto_attr_type *algt;
 593         struct crypto_instance *inst;
 594         struct hash_alg_common *auth;
 595         struct crypto_alg *auth_base;
 596         struct crypto_alg *enc;
 597         struct authenc_instance_ctx *ctx;
 598         const char *enc_name;
 599         int err;
 600
 601         algt = crypto_get_attr_type(tb);
 602         err = PTR_ERR(algt);
 603         if (IS_ERR(algt))
 604                 return ERR_PTR(err);
 605
 606         if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
 607                 return ERR_PTR(-EINVAL);
 608
 609         auth = ahash_attr_alg(tb[1], CRYPTO_ALG_TYPE_HASH,
 610                                CRYPTO_ALG_TYPE_AHASH_MASK);
 611         if (IS_ERR(auth))
 612                 return ERR_PTR(PTR_ERR(auth));
 613
 614         auth_base = &auth->base;
 615
 616         enc_name = crypto_attr_alg_name(tb[2]);
 617         err = PTR_ERR(enc_name);
 618         if (IS_ERR(enc_name))
 619                 goto out_put_auth;
 620
 621         inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
 622         err = -ENOMEM;
 623         if (!inst)
 624                 goto out_put_auth;
 625
 626         ctx = crypto_instance_ctx(inst);
 627
 628         err = crypto_init_ahash_spawn(&ctx->auth, auth, inst);
 629         if (err)
 630                 goto err_free_inst;
 631
 632         crypto_set_skcipher_spawn(&ctx->enc, inst);
 633         err = crypto_grab_skcipher(&ctx->enc, enc_name, 0,
 634                                    crypto_requires_sync(algt->type,
 635                                                         algt->mask));
 636         if (err)
 637                 goto err_drop_auth;
 638
 639         enc = crypto_skcipher_spawn_alg(&ctx->enc);
 640
 641         err = -ENAMETOOLONG;
 642         if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME,
 643                      "authenc(%s,%s)", auth_base->cra_name, enc->cra_name) >=
 644             CRYPTO_MAX_ALG_NAME)
 645                 goto err_drop_enc;
 646
 647         if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
 648                      "authenc(%s,%s)", auth_base->cra_driver_name,
 649                      enc->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
 650                 goto err_drop_enc;
 651
 652         inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD;
 653         inst->alg.cra_flags |= enc->cra_flags & CRYPTO_ALG_ASYNC;
 654         inst->alg.cra_priority = enc->cra_priority *
 655                                  10 + auth_base->cra_priority;
 656         inst->alg.cra_blocksize = enc->cra_blocksize;
 657         inst->alg.cra_alignmask = auth_base->cra_alignmask | enc->cra_alignmask;
 658         inst->alg.cra_type = &crypto_aead_type;
 659
 660         inst->alg.cra_aead.ivsize = enc->cra_ablkcipher.ivsize;
 661         inst->alg.cra_aead.maxauthsize = auth->digestsize;
 662
 663         inst->alg.cra_ctxsize = sizeof(struct crypto_authenc_ctx);
 664
 665         inst->alg.cra_init = crypto_authenc_init_tfm;
 666         inst->alg.cra_exit = crypto_authenc_exit_tfm;
 667
 668         inst->alg.cra_aead.setkey = crypto_authenc_setkey;
 669         inst->alg.cra_aead.encrypt = crypto_authenc_encrypt;
 670         inst->alg.cra_aead.decrypt = crypto_authenc_decrypt;
 671         inst->alg.cra_aead.givencrypt = crypto_authenc_givencrypt;
 672
 673 out:
 674         crypto_mod_put(auth_base);
 675         return inst;
 676
 677 err_drop_enc:
 678         crypto_drop_skcipher(&ctx->enc);
 679 err_drop_auth:
 680         crypto_drop_ahash(&ctx->auth);
 681 err_free_inst:
 682         kfree(inst);
 683 out_put_auth:
 684         inst = ERR_PTR(err);
 685         goto out;
 686 }
 687
 688 static void crypto_authenc_free(struct crypto_instance *inst)
 689 {
 690         struct authenc_instance_ctx *ctx = crypto_instance_ctx(inst);
 691
 692         crypto_drop_skcipher(&ctx->enc);
 693         crypto_drop_ahash(&ctx->auth);
 694         kfree(inst);
 695 }
 696
 697 static struct crypto_template crypto_authenc_tmpl = {
 698         .name = "authenc",
 699         .alloc = crypto_authenc_alloc,
 700         .free = crypto_authenc_free,
 701         .module = THIS_MODULE,
 702 };
 703
 704 static int __init crypto_authenc_module_init(void)
 705 {
 706         return crypto_register_template(&crypto_authenc_tmpl);
 707 }
 708
 709 static void __exit crypto_authenc_module_exit(void)
 710 {
 711         crypto_unregister_template(&crypto_authenc_tmpl);
 712 }
 713
 714 module_init(crypto_authenc_module_init);
 715 module_exit(crypto_authenc_module_exit);
 716
 717 MODULE_LICENSE("GPL");
 718 MODULE_DESCRIPTION("Simple AEAD wrapper for IPsec");