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 int crypto_authenc_extractkeys(struct crypto_authenc_keys *keys, const u8 *key,
  56                                unsigned int keylen)
  57 {
  58         struct rtattr *rta = (struct rtattr *)key;
  59         struct crypto_authenc_key_param *param;
  60
  61         if (!RTA_OK(rta, keylen))
  62                 return -EINVAL;
  63         if (rta->rta_type != CRYPTO_AUTHENC_KEYA_PARAM)
  64                 return -EINVAL;
  65         if (RTA_PAYLOAD(rta) < sizeof(*param))
  66                 return -EINVAL;
  67
  68         param = RTA_DATA(rta);
  69         keys->enckeylen = be32_to_cpu(param->enckeylen);
  70
  71         key += RTA_ALIGN(rta->rta_len);
  72         keylen -= RTA_ALIGN(rta->rta_len);
  73
  74         if (keylen < keys->enckeylen)
  75                 return -EINVAL;
  76
  77         keys->authkeylen = keylen - keys->enckeylen;
  78         keys->authkey = key;
  79         keys->enckey = key + keys->authkeylen;
  80
  81         return 0;
  82 }
  83 EXPORT_SYMBOL_GPL(crypto_authenc_extractkeys);
  84
  85 static int crypto_authenc_setkey(struct crypto_aead *authenc, const u8 *key,
  86                                  unsigned int keylen)
  87 {
  88         struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
  89         struct crypto_ahash *auth = ctx->auth;
  90         struct crypto_ablkcipher *enc = ctx->enc;
  91         struct crypto_authenc_keys keys;
  92         int err = -EINVAL;
  93
  94         if (crypto_authenc_extractkeys(&keys, key, keylen) != 0)
  95                 goto badkey;
  96
  97         crypto_ahash_clear_flags(auth, CRYPTO_TFM_REQ_MASK);
  98         crypto_ahash_set_flags(auth, crypto_aead_get_flags(authenc) &
  99                                     CRYPTO_TFM_REQ_MASK);
 100         err = crypto_ahash_setkey(auth, keys.authkey, keys.authkeylen);
 101         crypto_aead_set_flags(authenc, crypto_ahash_get_flags(auth) &
 102                                        CRYPTO_TFM_RES_MASK);
 103
 104         if (err)
 105                 goto out;
 106
 107         crypto_ablkcipher_clear_flags(enc, CRYPTO_TFM_REQ_MASK);
 108         crypto_ablkcipher_set_flags(enc, crypto_aead_get_flags(authenc) &
 109                                          CRYPTO_TFM_REQ_MASK);
 110         err = crypto_ablkcipher_setkey(enc, keys.enckey, keys.enckeylen);
 111         crypto_aead_set_flags(authenc, crypto_ablkcipher_get_flags(enc) &
 112                                        CRYPTO_TFM_RES_MASK);
 113
 114 out:
 115         return err;
 116
 117 badkey:
 118         crypto_aead_set_flags(authenc, CRYPTO_TFM_RES_BAD_KEY_LEN);
 119         goto out;
 120 }
 121
 122 static void authenc_geniv_ahash_update_done(struct crypto_async_request *areq,
 123                                             int err)
 124 {
 125         struct aead_request *req = areq->data;
 126         struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 127         struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
 128         struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
 129         struct ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
 130
 131         if (err)
 132                 goto out;
 133
 134         ahash_request_set_crypt(ahreq, areq_ctx->sg, ahreq->result,
 135                                 areq_ctx->cryptlen);
 136         ahash_request_set_callback(ahreq, aead_request_flags(req) &
 137                                           CRYPTO_TFM_REQ_MAY_SLEEP,
 138                                    areq_ctx->complete, req);
 139
 140         err = crypto_ahash_finup(ahreq);
 141         if (err)
 142                 goto out;
 143
 144         scatterwalk_map_and_copy(ahreq->result, areq_ctx->sg,
 145                                  areq_ctx->cryptlen,
 146                                  crypto_aead_authsize(authenc), 1);
 147
 148 out:
 149         authenc_request_complete(req, err);
 150 }
 151
 152 static void authenc_geniv_ahash_done(struct crypto_async_request *areq, int err)
 153 {
 154         struct aead_request *req = areq->data;
 155         struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 156         struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
 157         struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
 158         struct ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
 159
 160         if (err)
 161                 goto out;
 162
 163         scatterwalk_map_and_copy(ahreq->result, areq_ctx->sg,
 164                                  areq_ctx->cryptlen,
 165                                  crypto_aead_authsize(authenc), 1);
 166
 167 out:
 168         aead_request_complete(req, err);
 169 }
 170
 171 static void authenc_verify_ahash_update_done(struct crypto_async_request *areq,
 172                                              int err)
 173 {
 174         u8 *ihash;
 175         unsigned int authsize;
 176         struct ablkcipher_request *abreq;
 177         struct aead_request *req = areq->data;
 178         struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 179         struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
 180         struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
 181         struct ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
 182         unsigned int cryptlen = req->cryptlen;
 183
 184         if (err)
 185                 goto out;
 186
 187         ahash_request_set_crypt(ahreq, areq_ctx->sg, ahreq->result,
 188                                 areq_ctx->cryptlen);
 189         ahash_request_set_callback(ahreq, aead_request_flags(req) &
 190                                           CRYPTO_TFM_REQ_MAY_SLEEP,
 191                                    areq_ctx->complete, req);
 192
 193         err = crypto_ahash_finup(ahreq);
 194         if (err)
 195                 goto out;
 196
 197         authsize = crypto_aead_authsize(authenc);
 198         cryptlen -= authsize;
 199         ihash = ahreq->result + authsize;
 200         scatterwalk_map_and_copy(ihash, areq_ctx->sg, areq_ctx->cryptlen,
 201                                  authsize, 0);
 202
 203         err = crypto_memneq(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                                      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         unsigned int cryptlen = req->cryptlen;
 232
 233         if (err)
 234                 goto out;
 235
 236         authsize = crypto_aead_authsize(authenc);
 237         cryptlen -= authsize;
 238         ihash = ahreq->result + authsize;
 239         scatterwalk_map_and_copy(ihash, areq_ctx->sg, areq_ctx->cryptlen,
 240                                  authsize, 0);
 241
 242         err = crypto_memneq(ihash, ahreq->result, authsize) ? -EBADMSG : 0;
 243         if (err)
 244                 goto out;
 245
 246         abreq = aead_request_ctx(req);
 247         ablkcipher_request_set_tfm(abreq, ctx->enc);
 248         ablkcipher_request_set_callback(abreq, aead_request_flags(req),
 249                                         req->base.complete, req->base.data);
 250         ablkcipher_request_set_crypt(abreq, req->src, req->dst,
 251                                      cryptlen, req->iv);
 252
 253         err = crypto_ablkcipher_decrypt(abreq);
 254
 255 out:
 256         authenc_request_complete(req, err);
 257 }
 258
 259 static u8 *crypto_authenc_ahash_fb(struct aead_request *req, unsigned int flags)
 260 {
 261         struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 262         struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
 263         struct crypto_ahash *auth = ctx->auth;
 264         struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
 265         struct ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
 266         u8 *hash = areq_ctx->tail;
 267         int err;
 268
 269         hash = (u8 *)ALIGN((unsigned long)hash + crypto_ahash_alignmask(auth),
 270                             crypto_ahash_alignmask(auth) + 1);
 271
 272         ahash_request_set_tfm(ahreq, auth);
 273
 274         err = crypto_ahash_init(ahreq);
 275         if (err)
 276                 return ERR_PTR(err);
 277
 278         ahash_request_set_crypt(ahreq, req->assoc, hash, req->assoclen);
 279         ahash_request_set_callback(ahreq, aead_request_flags(req) & flags,
 280                                    areq_ctx->update_complete, req);
 281
 282         err = crypto_ahash_update(ahreq);
 283         if (err)
 284                 return ERR_PTR(err);
 285
 286         ahash_request_set_crypt(ahreq, areq_ctx->sg, hash,
 287                                 areq_ctx->cryptlen);
 288         ahash_request_set_callback(ahreq, aead_request_flags(req) & flags,
 289                                    areq_ctx->complete, req);
 290
 291         err = crypto_ahash_finup(ahreq);
 292         if (err)
 293                 return ERR_PTR(err);
 294
 295         return hash;
 296 }
 297
 298 static u8 *crypto_authenc_ahash(struct aead_request *req, unsigned int flags)
 299 {
 300         struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 301         struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
 302         struct crypto_ahash *auth = ctx->auth;
 303         struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
 304         struct ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
 305         u8 *hash = areq_ctx->tail;
 306         int err;
 307
 308         hash = (u8 *)ALIGN((unsigned long)hash + crypto_ahash_alignmask(auth),
 309                            crypto_ahash_alignmask(auth) + 1);
 310
 311         ahash_request_set_tfm(ahreq, auth);
 312         ahash_request_set_crypt(ahreq, areq_ctx->sg, hash,
 313                                 areq_ctx->cryptlen);
 314         ahash_request_set_callback(ahreq, aead_request_flags(req) & flags,
 315                                    areq_ctx->complete, req);
 316
 317         err = crypto_ahash_digest(ahreq);
 318         if (err)
 319                 return ERR_PTR(err);
 320
 321         return hash;
 322 }
 323
 324 static int crypto_authenc_genicv(struct aead_request *req, u8 *iv,
 325                                  unsigned int flags)
 326 {
 327         struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 328         struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
 329         struct scatterlist *dst = req->dst;
 330         struct scatterlist *assoc = req->assoc;
 331         struct scatterlist *cipher = areq_ctx->cipher;
 332         struct scatterlist *asg = areq_ctx->asg;
 333         unsigned int ivsize = crypto_aead_ivsize(authenc);
 334         unsigned int cryptlen = req->cryptlen;
 335         authenc_ahash_t authenc_ahash_fn = crypto_authenc_ahash_fb;
 336         struct page *dstp;
 337         u8 *vdst;
 338         u8 *hash;
 339
 340         dstp = sg_page(dst);
 341         vdst = PageHighMem(dstp) ? NULL : page_address(dstp) + dst->offset;
 342
 343         if (ivsize) {
 344                 sg_init_table(cipher, 2);
 345                 sg_set_buf(cipher, iv, ivsize);
 346                 scatterwalk_crypto_chain(cipher, dst, vdst == iv + ivsize, 2);
 347                 dst = cipher;
 348                 cryptlen += ivsize;
 349         }
 350
 351         if (req->assoclen && sg_is_last(assoc)) {
 352                 authenc_ahash_fn = crypto_authenc_ahash;
 353                 sg_init_table(asg, 2);
 354                 sg_set_page(asg, sg_page(assoc), assoc->length, assoc->offset);
 355                 scatterwalk_crypto_chain(asg, dst, 0, 2);
 356                 dst = asg;
 357                 cryptlen += req->assoclen;
 358         }
 359
 360         areq_ctx->cryptlen = cryptlen;
 361         areq_ctx->sg = dst;
 362
 363         areq_ctx->complete = authenc_geniv_ahash_done;
 364         areq_ctx->update_complete = authenc_geniv_ahash_update_done;
 365
 366         hash = authenc_ahash_fn(req, flags);
 367         if (IS_ERR(hash))
 368                 return PTR_ERR(hash);
 369
 370         scatterwalk_map_and_copy(hash, dst, cryptlen,
 371                                  crypto_aead_authsize(authenc), 1);
 372         return 0;
 373 }
 374
 375 static void crypto_authenc_encrypt_done(struct crypto_async_request *req,
 376                                         int err)
 377 {
 378         struct aead_request *areq = req->data;
 379
 380         if (!err) {
 381                 struct crypto_aead *authenc = crypto_aead_reqtfm(areq);
 382                 struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
 383                 struct ablkcipher_request *abreq = aead_request_ctx(areq);
 384                 u8 *iv = (u8 *)(abreq + 1) +
 385                          crypto_ablkcipher_reqsize(ctx->enc);
 386
 387                 err = crypto_authenc_genicv(areq, iv, 0);
 388         }
 389
 390         authenc_request_complete(areq, err);
 391 }
 392
 393 static int crypto_authenc_encrypt(struct aead_request *req)
 394 {
 395         struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 396         struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
 397         struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
 398         struct crypto_ablkcipher *enc = ctx->enc;
 399         struct scatterlist *dst = req->dst;
 400         unsigned int cryptlen = req->cryptlen;
 401         struct ablkcipher_request *abreq = (void *)(areq_ctx->tail
 402                                                     + ctx->reqoff);
 403         u8 *iv = (u8 *)abreq - crypto_ablkcipher_ivsize(enc);
 404         int err;
 405
 406         ablkcipher_request_set_tfm(abreq, enc);
 407         ablkcipher_request_set_callback(abreq, aead_request_flags(req),
 408                                         crypto_authenc_encrypt_done, req);
 409         ablkcipher_request_set_crypt(abreq, req->src, dst, cryptlen, req->iv);
 410
 411         memcpy(iv, req->iv, crypto_aead_ivsize(authenc));
 412
 413         err = crypto_ablkcipher_encrypt(abreq);
 414         if (err)
 415                 return err;
 416
 417         return crypto_authenc_genicv(req, iv, CRYPTO_TFM_REQ_MAY_SLEEP);
 418 }
 419
 420 static void crypto_authenc_givencrypt_done(struct crypto_async_request *req,
 421                                            int err)
 422 {
 423         struct aead_request *areq = req->data;
 424
 425         if (!err) {
 426                 struct skcipher_givcrypt_request *greq = aead_request_ctx(areq);
 427
 428                 err = crypto_authenc_genicv(areq, greq->giv, 0);
 429         }
 430
 431         authenc_request_complete(areq, err);
 432 }
 433
 434 static int crypto_authenc_givencrypt(struct aead_givcrypt_request *req)
 435 {
 436         struct crypto_aead *authenc = aead_givcrypt_reqtfm(req);
 437         struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
 438         struct aead_request *areq = &req->areq;
 439         struct skcipher_givcrypt_request *greq = aead_request_ctx(areq);
 440         u8 *iv = req->giv;
 441         int err;
 442
 443         skcipher_givcrypt_set_tfm(greq, ctx->enc);
 444         skcipher_givcrypt_set_callback(greq, aead_request_flags(areq),
 445                                        crypto_authenc_givencrypt_done, areq);
 446         skcipher_givcrypt_set_crypt(greq, areq->src, areq->dst, areq->cryptlen,
 447                                     areq->iv);
 448         skcipher_givcrypt_set_giv(greq, iv, req->seq);
 449
 450         err = crypto_skcipher_givencrypt(greq);
 451         if (err)
 452                 return err;
 453
 454         return crypto_authenc_genicv(areq, iv, CRYPTO_TFM_REQ_MAY_SLEEP);
 455 }
 456
 457 static int crypto_authenc_verify(struct aead_request *req,
 458                                  authenc_ahash_t authenc_ahash_fn)
 459 {
 460         struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 461         struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
 462         u8 *ohash;
 463         u8 *ihash;
 464         unsigned int authsize;
 465
 466         areq_ctx->complete = authenc_verify_ahash_done;
 467         areq_ctx->update_complete = authenc_verify_ahash_update_done;
 468
 469         ohash = authenc_ahash_fn(req, CRYPTO_TFM_REQ_MAY_SLEEP);
 470         if (IS_ERR(ohash))
 471                 return PTR_ERR(ohash);
 472
 473         authsize = crypto_aead_authsize(authenc);
 474         ihash = ohash + authsize;
 475         scatterwalk_map_and_copy(ihash, areq_ctx->sg, areq_ctx->cryptlen,
 476                                  authsize, 0);
 477         return crypto_memneq(ihash, ohash, authsize) ? -EBADMSG : 0;
 478 }
 479
 480 static int crypto_authenc_iverify(struct aead_request *req, u8 *iv,
 481                                   unsigned int cryptlen)
 482 {
 483         struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 484         struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
 485         struct scatterlist *src = req->src;
 486         struct scatterlist *assoc = req->assoc;
 487         struct scatterlist *cipher = areq_ctx->cipher;
 488         struct scatterlist *asg = areq_ctx->asg;
 489         unsigned int ivsize = crypto_aead_ivsize(authenc);
 490         authenc_ahash_t authenc_ahash_fn = crypto_authenc_ahash_fb;
 491         struct page *srcp;
 492         u8 *vsrc;
 493
 494         srcp = sg_page(src);
 495         vsrc = PageHighMem(srcp) ? NULL : page_address(srcp) + src->offset;
 496
 497         if (ivsize) {
 498                 sg_init_table(cipher, 2);
 499                 sg_set_buf(cipher, iv, ivsize);
 500                 scatterwalk_crypto_chain(cipher, src, vsrc == iv + ivsize, 2);
 501                 src = cipher;
 502                 cryptlen += ivsize;
 503         }
 504
 505         if (req->assoclen && sg_is_last(assoc)) {
 506                 authenc_ahash_fn = crypto_authenc_ahash;
 507                 sg_init_table(asg, 2);
 508                 sg_set_page(asg, sg_page(assoc), assoc->length, assoc->offset);
 509                 scatterwalk_crypto_chain(asg, src, 0, 2);
 510                 src = asg;
 511                 cryptlen += req->assoclen;
 512         }
 513
 514         areq_ctx->cryptlen = cryptlen;
 515         areq_ctx->sg = src;
 516
 517         return crypto_authenc_verify(req, authenc_ahash_fn);
 518 }
 519
 520 static int crypto_authenc_decrypt(struct aead_request *req)
 521 {
 522         struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 523         struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
 524         struct ablkcipher_request *abreq = aead_request_ctx(req);
 525         unsigned int cryptlen = req->cryptlen;
 526         unsigned int authsize = crypto_aead_authsize(authenc);
 527         u8 *iv = req->iv;
 528         int err;
 529
 530         if (cryptlen < authsize)
 531                 return -EINVAL;
 532         cryptlen -= authsize;
 533
 534         err = crypto_authenc_iverify(req, iv, cryptlen);
 535         if (err)
 536                 return err;
 537
 538         ablkcipher_request_set_tfm(abreq, ctx->enc);
 539         ablkcipher_request_set_callback(abreq, aead_request_flags(req),
 540                                         req->base.complete, req->base.data);
 541         ablkcipher_request_set_crypt(abreq, req->src, req->dst, cryptlen, iv);
 542
 543         return crypto_ablkcipher_decrypt(abreq);
 544 }
 545
 546 static int crypto_authenc_init_tfm(struct crypto_tfm *tfm)
 547 {
 548         struct crypto_instance *inst = crypto_tfm_alg_instance(tfm);
 549         struct authenc_instance_ctx *ictx = crypto_instance_ctx(inst);
 550         struct crypto_authenc_ctx *ctx = crypto_tfm_ctx(tfm);
 551         struct crypto_ahash *auth;
 552         struct crypto_ablkcipher *enc;
 553         int err;
 554
 555         auth = crypto_spawn_ahash(&ictx->auth);
 556         if (IS_ERR(auth))
 557                 return PTR_ERR(auth);
 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         ctx->reqoff = ALIGN(2 * crypto_ahash_digestsize(auth) +
 568                             crypto_ahash_alignmask(auth),
 569                             crypto_ahash_alignmask(auth) + 1) +
 570                       crypto_ablkcipher_ivsize(enc);
 571
 572         tfm->crt_aead.reqsize = sizeof(struct authenc_request_ctx) +
 573                                 ctx->reqoff +
 574                                 max_t(unsigned int,
 575                                 crypto_ahash_reqsize(auth) +
 576                                 sizeof(struct ahash_request),
 577                                 sizeof(struct skcipher_givcrypt_request) +
 578                                 crypto_ablkcipher_reqsize(enc));
 579
 580         return 0;
 581
 582 err_free_ahash:
 583         crypto_free_ahash(auth);
 584         return err;
 585 }
 586
 587 static void crypto_authenc_exit_tfm(struct crypto_tfm *tfm)
 588 {
 589         struct crypto_authenc_ctx *ctx = crypto_tfm_ctx(tfm);
 590
 591         crypto_free_ahash(ctx->auth);
 592         crypto_free_ablkcipher(ctx->enc);
 593 }
 594
 595 static struct crypto_instance *crypto_authenc_alloc(struct rtattr **tb)
 596 {
 597         struct crypto_attr_type *algt;
 598         struct crypto_instance *inst;
 599         struct hash_alg_common *auth;
 600         struct crypto_alg *auth_base;
 601         struct crypto_alg *enc;
 602         struct authenc_instance_ctx *ctx;
 603         const char *enc_name;
 604         int err;
 605
 606         algt = crypto_get_attr_type(tb);
 607         if (IS_ERR(algt))
 608                 return ERR_CAST(algt);
 609
 610         if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
 611                 return ERR_PTR(-EINVAL);
 612
 613         auth = ahash_attr_alg(tb[1], CRYPTO_ALG_TYPE_HASH,
 614                                CRYPTO_ALG_TYPE_AHASH_MASK);
 615         if (IS_ERR(auth))
 616                 return ERR_CAST(auth);
 617
 618         auth_base = &auth->base;
 619
 620         enc_name = crypto_attr_alg_name(tb[2]);
 621         err = PTR_ERR(enc_name);
 622         if (IS_ERR(enc_name))
 623                 goto out_put_auth;
 624
 625         inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
 626         err = -ENOMEM;
 627         if (!inst)
 628                 goto out_put_auth;
 629
 630         ctx = crypto_instance_ctx(inst);
 631
 632         err = crypto_init_ahash_spawn(&ctx->auth, auth, inst);
 633         if (err)
 634                 goto err_free_inst;
 635
 636         crypto_set_skcipher_spawn(&ctx->enc, inst);
 637         err = crypto_grab_skcipher(&ctx->enc, enc_name, 0,
 638                                    crypto_requires_sync(algt->type,
 639                                                         algt->mask));
 640         if (err)
 641                 goto err_drop_auth;
 642
 643         enc = crypto_skcipher_spawn_alg(&ctx->enc);
 644
 645         err = -ENAMETOOLONG;
 646         if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME,
 647                      "authenc(%s,%s)", auth_base->cra_name, enc->cra_name) >=
 648             CRYPTO_MAX_ALG_NAME)
 649                 goto err_drop_enc;
 650
 651         if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
 652                      "authenc(%s,%s)", auth_base->cra_driver_name,
 653                      enc->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
 654                 goto err_drop_enc;
 655
 656         inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD;
 657         inst->alg.cra_flags |= enc->cra_flags & CRYPTO_ALG_ASYNC;
 658         inst->alg.cra_priority = enc->cra_priority *
 659                                  10 + auth_base->cra_priority;
 660         inst->alg.cra_blocksize = enc->cra_blocksize;
 661         inst->alg.cra_alignmask = auth_base->cra_alignmask | enc->cra_alignmask;
 662         inst->alg.cra_type = &crypto_aead_type;
 663
 664         inst->alg.cra_aead.ivsize = enc->cra_ablkcipher.ivsize;
 665         inst->alg.cra_aead.maxauthsize = auth->digestsize;
 666
 667         inst->alg.cra_ctxsize = sizeof(struct crypto_authenc_ctx);
 668
 669         inst->alg.cra_init = crypto_authenc_init_tfm;
 670         inst->alg.cra_exit = crypto_authenc_exit_tfm;
 671
 672         inst->alg.cra_aead.setkey = crypto_authenc_setkey;
 673         inst->alg.cra_aead.encrypt = crypto_authenc_encrypt;
 674         inst->alg.cra_aead.decrypt = crypto_authenc_decrypt;
 675         inst->alg.cra_aead.givencrypt = crypto_authenc_givencrypt;
 676
 677 out:
 678         crypto_mod_put(auth_base);
 679         return inst;
 680
 681 err_drop_enc:
 682         crypto_drop_skcipher(&ctx->enc);
 683 err_drop_auth:
 684         crypto_drop_ahash(&ctx->auth);
 685 err_free_inst:
 686         kfree(inst);
 687 out_put_auth:
 688         inst = ERR_PTR(err);
 689         goto out;
 690 }
 691
 692 static void crypto_authenc_free(struct crypto_instance *inst)
 693 {
 694         struct authenc_instance_ctx *ctx = crypto_instance_ctx(inst);
 695
 696         crypto_drop_skcipher(&ctx->enc);
 697         crypto_drop_ahash(&ctx->auth);
 698         kfree(inst);
 699 }
 700
 701 static struct crypto_template crypto_authenc_tmpl = {
 702         .name = "authenc",
 703         .alloc = crypto_authenc_alloc,
 704         .free = crypto_authenc_free,
 705         .module = THIS_MODULE,
 706 };
 707
 708 static int __init crypto_authenc_module_init(void)
 709 {
 710         return crypto_register_template(&crypto_authenc_tmpl);
 711 }
 712
 713 static void __exit crypto_authenc_module_exit(void)
 714 {
 715         crypto_unregister_template(&crypto_authenc_tmpl);
 716 }
 717
 718 module_init(crypto_authenc_module_init);
 719 module_exit(crypto_authenc_module_exit);
 720
 721 MODULE_LICENSE("GPL");
 722 MODULE_DESCRIPTION("Simple AEAD wrapper for IPsec");