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 authenc_request_ctx *areq_ctx = aead_request_ctx(req);
 396         struct crypto_ablkcipher *enc = ctx->enc;
 397         struct scatterlist *dst = req->dst;
 398         unsigned int cryptlen = req->cryptlen;
 399         struct ablkcipher_request *abreq = (void *)(areq_ctx->tail
 400                                                     + ctx->reqoff);
 401         u8 *iv = (u8 *)abreq - crypto_ablkcipher_ivsize(enc);
 402         int err;
 403
 404         ablkcipher_request_set_tfm(abreq, enc);
 405         ablkcipher_request_set_callback(abreq, aead_request_flags(req),
 406                                         crypto_authenc_encrypt_done, req);
 407         ablkcipher_request_set_crypt(abreq, req->src, dst, cryptlen, req->iv);
 408
 409         memcpy(iv, req->iv, crypto_aead_ivsize(authenc));
 410
 411         err = crypto_ablkcipher_encrypt(abreq);
 412         if (err)
 413                 return err;
 414
 415         return crypto_authenc_genicv(req, iv, CRYPTO_TFM_REQ_MAY_SLEEP);
 416 }
 417
 418 static void crypto_authenc_givencrypt_done(struct crypto_async_request *req,
 419                                            int err)
 420 {
 421         struct aead_request *areq = req->data;
 422
 423         if (!err) {
 424                 struct skcipher_givcrypt_request *greq = aead_request_ctx(areq);
 425
 426                 err = crypto_authenc_genicv(areq, greq->giv, 0);
 427         }
 428
 429         authenc_request_complete(areq, err);
 430 }
 431
 432 static int crypto_authenc_givencrypt(struct aead_givcrypt_request *req)
 433 {
 434         struct crypto_aead *authenc = aead_givcrypt_reqtfm(req);
 435         struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
 436         struct aead_request *areq = &req->areq;
 437         struct skcipher_givcrypt_request *greq = aead_request_ctx(areq);
 438         u8 *iv = req->giv;
 439         int err;
 440
 441         skcipher_givcrypt_set_tfm(greq, ctx->enc);
 442         skcipher_givcrypt_set_callback(greq, aead_request_flags(areq),
 443                                        crypto_authenc_givencrypt_done, areq);
 444         skcipher_givcrypt_set_crypt(greq, areq->src, areq->dst, areq->cryptlen,
 445                                     areq->iv);
 446         skcipher_givcrypt_set_giv(greq, iv, req->seq);
 447
 448         err = crypto_skcipher_givencrypt(greq);
 449         if (err)
 450                 return err;
 451
 452         return crypto_authenc_genicv(areq, iv, CRYPTO_TFM_REQ_MAY_SLEEP);
 453 }
 454
 455 static int crypto_authenc_verify(struct aead_request *req,
 456                                  authenc_ahash_t authenc_ahash_fn)
 457 {
 458         struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 459         struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
 460         u8 *ohash;
 461         u8 *ihash;
 462         unsigned int authsize;
 463
 464         areq_ctx->complete = authenc_verify_ahash_done;
 465         areq_ctx->update_complete = authenc_verify_ahash_update_done;
 466
 467         ohash = authenc_ahash_fn(req, CRYPTO_TFM_REQ_MAY_SLEEP);
 468         if (IS_ERR(ohash))
 469                 return PTR_ERR(ohash);
 470
 471         authsize = crypto_aead_authsize(authenc);
 472         ihash = ohash + authsize;
 473         scatterwalk_map_and_copy(ihash, areq_ctx->sg, areq_ctx->cryptlen,
 474                                  authsize, 0);
 475         return memcmp(ihash, ohash, authsize) ? -EBADMSG : 0;
 476 }
 477
 478 static int crypto_authenc_iverify(struct aead_request *req, u8 *iv,
 479                                   unsigned int cryptlen)
 480 {
 481         struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 482         struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
 483         struct scatterlist *src = req->src;
 484         struct scatterlist *assoc = req->assoc;
 485         struct scatterlist *cipher = areq_ctx->cipher;
 486         struct scatterlist *asg = areq_ctx->asg;
 487         unsigned int ivsize = crypto_aead_ivsize(authenc);
 488         authenc_ahash_t authenc_ahash_fn = crypto_authenc_ahash_fb;
 489         struct page *srcp;
 490         u8 *vsrc;
 491
 492         srcp = sg_page(src);
 493         vsrc = PageHighMem(srcp) ? NULL : page_address(srcp) + src->offset;
 494
 495         if (ivsize) {
 496                 sg_init_table(cipher, 2);
 497                 sg_set_buf(cipher, iv, ivsize);
 498                 authenc_chain(cipher, src, vsrc == iv + ivsize);
 499                 src = cipher;
 500                 cryptlen += ivsize;
 501         }
 502
 503         if (sg_is_last(assoc)) {
 504                 authenc_ahash_fn = crypto_authenc_ahash;
 505                 sg_init_table(asg, 2);
 506                 sg_set_page(asg, sg_page(assoc), assoc->length, assoc->offset);
 507                 authenc_chain(asg, src, 0);
 508                 src = asg;
 509                 cryptlen += req->assoclen;
 510         }
 511
 512         areq_ctx->cryptlen = cryptlen;
 513         areq_ctx->sg = src;
 514
 515         return crypto_authenc_verify(req, authenc_ahash_fn);
 516 }
 517
 518 static int crypto_authenc_decrypt(struct aead_request *req)
 519 {
 520         struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 521         struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
 522         struct ablkcipher_request *abreq = aead_request_ctx(req);
 523         unsigned int cryptlen = req->cryptlen;
 524         unsigned int authsize = crypto_aead_authsize(authenc);
 525         u8 *iv = req->iv;
 526         int err;
 527
 528         if (cryptlen < authsize)
 529                 return -EINVAL;
 530         cryptlen -= authsize;
 531
 532         err = crypto_authenc_iverify(req, iv, cryptlen);
 533         if (err)
 534                 return err;
 535
 536         ablkcipher_request_set_tfm(abreq, ctx->enc);
 537         ablkcipher_request_set_callback(abreq, aead_request_flags(req),
 538                                         req->base.complete, req->base.data);
 539         ablkcipher_request_set_crypt(abreq, req->src, req->dst, cryptlen, iv);
 540
 541         return crypto_ablkcipher_decrypt(abreq);
 542 }
 543
 544 static int crypto_authenc_init_tfm(struct crypto_tfm *tfm)
 545 {
 546         struct crypto_instance *inst = crypto_tfm_alg_instance(tfm);
 547         struct authenc_instance_ctx *ictx = crypto_instance_ctx(inst);
 548         struct crypto_authenc_ctx *ctx = crypto_tfm_ctx(tfm);
 549         struct crypto_ahash *auth;
 550         struct crypto_ablkcipher *enc;
 551         int err;
 552
 553         auth = crypto_spawn_ahash(&ictx->auth);
 554         if (IS_ERR(auth))
 555                 return PTR_ERR(auth);
 556
 557         enc = crypto_spawn_skcipher(&ictx->enc);
 558         err = PTR_ERR(enc);
 559         if (IS_ERR(enc))
 560                 goto err_free_ahash;
 561
 562         ctx->auth = auth;
 563         ctx->enc = enc;
 564
 565         ctx->reqoff = ALIGN(2 * crypto_ahash_digestsize(auth) +
 566                             crypto_ahash_alignmask(auth),
 567                             crypto_ahash_alignmask(auth) + 1) +
 568                       crypto_ablkcipher_ivsize(enc);
 569
 570         tfm->crt_aead.reqsize = sizeof(struct authenc_request_ctx) +
 571                                 ctx->reqoff +
 572                                 max_t(unsigned int,
 573                                 crypto_ahash_reqsize(auth) +
 574                                 sizeof(struct ahash_request),
 575                                 sizeof(struct skcipher_givcrypt_request) +
 576                                 crypto_ablkcipher_reqsize(enc));
 577
 578         return 0;
 579
 580 err_free_ahash:
 581         crypto_free_ahash(auth);
 582         return err;
 583 }
 584
 585 static void crypto_authenc_exit_tfm(struct crypto_tfm *tfm)
 586 {
 587         struct crypto_authenc_ctx *ctx = crypto_tfm_ctx(tfm);
 588
 589         crypto_free_ahash(ctx->auth);
 590         crypto_free_ablkcipher(ctx->enc);
 591 }
 592
 593 static struct crypto_instance *crypto_authenc_alloc(struct rtattr **tb)
 594 {
 595         struct crypto_attr_type *algt;
 596         struct crypto_instance *inst;
 597         struct hash_alg_common *auth;
 598         struct crypto_alg *auth_base;
 599         struct crypto_alg *enc;
 600         struct authenc_instance_ctx *ctx;
 601         const char *enc_name;
 602         int err;
 603
 604         algt = crypto_get_attr_type(tb);
 605         err = PTR_ERR(algt);
 606         if (IS_ERR(algt))
 607                 return ERR_PTR(err);
 608
 609         if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
 610                 return ERR_PTR(-EINVAL);
 611
 612         auth = ahash_attr_alg(tb[1], CRYPTO_ALG_TYPE_HASH,
 613                                CRYPTO_ALG_TYPE_AHASH_MASK);
 614         if (IS_ERR(auth))
 615                 return ERR_PTR(PTR_ERR(auth));
 616
 617         auth_base = &auth->base;
 618
 619         enc_name = crypto_attr_alg_name(tb[2]);
 620         err = PTR_ERR(enc_name);
 621         if (IS_ERR(enc_name))
 622                 goto out_put_auth;
 623
 624         inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
 625         err = -ENOMEM;
 626         if (!inst)
 627                 goto out_put_auth;
 628
 629         ctx = crypto_instance_ctx(inst);
 630
 631         err = crypto_init_ahash_spawn(&ctx->auth, auth, inst);
 632         if (err)
 633                 goto err_free_inst;
 634
 635         crypto_set_skcipher_spawn(&ctx->enc, inst);
 636         err = crypto_grab_skcipher(&ctx->enc, enc_name, 0,
 637                                    crypto_requires_sync(algt->type,
 638                                                         algt->mask));
 639         if (err)
 640                 goto err_drop_auth;
 641
 642         enc = crypto_skcipher_spawn_alg(&ctx->enc);
 643
 644         err = -ENAMETOOLONG;
 645         if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME,
 646                      "authenc(%s,%s)", auth_base->cra_name, enc->cra_name) >=
 647             CRYPTO_MAX_ALG_NAME)
 648                 goto err_drop_enc;
 649
 650         if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
 651                      "authenc(%s,%s)", auth_base->cra_driver_name,
 652                      enc->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
 653                 goto err_drop_enc;
 654
 655         inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD;
 656         inst->alg.cra_flags |= enc->cra_flags & CRYPTO_ALG_ASYNC;
 657         inst->alg.cra_priority = enc->cra_priority *
 658                                  10 + auth_base->cra_priority;
 659         inst->alg.cra_blocksize = enc->cra_blocksize;
 660         inst->alg.cra_alignmask = auth_base->cra_alignmask | enc->cra_alignmask;
 661         inst->alg.cra_type = &crypto_aead_type;
 662
 663         inst->alg.cra_aead.ivsize = enc->cra_ablkcipher.ivsize;
 664         inst->alg.cra_aead.maxauthsize = auth->digestsize;
 665
 666         inst->alg.cra_ctxsize = sizeof(struct crypto_authenc_ctx);
 667
 668         inst->alg.cra_init = crypto_authenc_init_tfm;
 669         inst->alg.cra_exit = crypto_authenc_exit_tfm;
 670
 671         inst->alg.cra_aead.setkey = crypto_authenc_setkey;
 672         inst->alg.cra_aead.encrypt = crypto_authenc_encrypt;
 673         inst->alg.cra_aead.decrypt = crypto_authenc_decrypt;
 674         inst->alg.cra_aead.givencrypt = crypto_authenc_givencrypt;
 675
 676 out:
 677         crypto_mod_put(auth_base);
 678         return inst;
 679
 680 err_drop_enc:
 681         crypto_drop_skcipher(&ctx->enc);
 682 err_drop_auth:
 683         crypto_drop_ahash(&ctx->auth);
 684 err_free_inst:
 685         kfree(inst);
 686 out_put_auth:
 687         inst = ERR_PTR(err);
 688         goto out;
 689 }
 690
 691 static void crypto_authenc_free(struct crypto_instance *inst)
 692 {
 693         struct authenc_instance_ctx *ctx = crypto_instance_ctx(inst);
 694
 695         crypto_drop_skcipher(&ctx->enc);
 696         crypto_drop_ahash(&ctx->auth);
 697         kfree(inst);
 698 }
 699
 700 static struct crypto_template crypto_authenc_tmpl = {
 701         .name = "authenc",
 702         .alloc = crypto_authenc_alloc,
 703         .free = crypto_authenc_free,
 704         .module = THIS_MODULE,
 705 };
 706
 707 static int __init crypto_authenc_module_init(void)
 708 {
 709         return crypto_register_template(&crypto_authenc_tmpl);
 710 }
 711
 712 static void __exit crypto_authenc_module_exit(void)
 713 {
 714         crypto_unregister_template(&crypto_authenc_tmpl);
 715 }
 716
 717 module_init(crypto_authenc_module_init);
 718 module_exit(crypto_authenc_module_exit);
 719
 720 MODULE_LICENSE("GPL");
 721 MODULE_DESCRIPTION("Simple AEAD wrapper for IPsec");