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 int crypto_authenc_setkey(struct crypto_aead *authenc, const u8 *key,
  50                                  unsigned int keylen)
  51 {
  52         unsigned int authkeylen;
  53         unsigned int enckeylen;
  54         struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
  55         struct crypto_ahash *auth = ctx->auth;
  56         struct crypto_ablkcipher *enc = ctx->enc;
  57         struct rtattr *rta = (void *)key;
  58         struct crypto_authenc_key_param *param;
  59         int err = -EINVAL;
  60
  61         if (!RTA_OK(rta, keylen))
  62                 goto badkey;
  63         if (rta->rta_type != CRYPTO_AUTHENC_KEYA_PARAM)
  64                 goto badkey;
  65         if (RTA_PAYLOAD(rta) < sizeof(*param))
  66                 goto badkey;
  67
  68         param = RTA_DATA(rta);
  69         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 < enckeylen)
  75                 goto badkey;
  76
  77         authkeylen = keylen - enckeylen;
  78
  79         crypto_ahash_clear_flags(auth, CRYPTO_TFM_REQ_MASK);
  80         crypto_ahash_set_flags(auth, crypto_aead_get_flags(authenc) &
  81                                     CRYPTO_TFM_REQ_MASK);
  82         err = crypto_ahash_setkey(auth, key, authkeylen);
  83         crypto_aead_set_flags(authenc, crypto_ahash_get_flags(auth) &
  84                                        CRYPTO_TFM_RES_MASK);
  85
  86         if (err)
  87                 goto out;
  88
  89         crypto_ablkcipher_clear_flags(enc, CRYPTO_TFM_REQ_MASK);
  90         crypto_ablkcipher_set_flags(enc, crypto_aead_get_flags(authenc) &
  91                                          CRYPTO_TFM_REQ_MASK);
  92         err = crypto_ablkcipher_setkey(enc, key + authkeylen, enckeylen);
  93         crypto_aead_set_flags(authenc, crypto_ablkcipher_get_flags(enc) &
  94                                        CRYPTO_TFM_RES_MASK);
  95
  96 out:
  97         return err;
  98
  99 badkey:
 100         crypto_aead_set_flags(authenc, CRYPTO_TFM_RES_BAD_KEY_LEN);
 101         goto out;
 102 }
 103
 104 static void authenc_chain(struct scatterlist *head, struct scatterlist *sg,
 105                           int chain)
 106 {
 107         if (chain) {
 108                 head->length += sg->length;
 109                 sg = scatterwalk_sg_next(sg);
 110         }
 111
 112         if (sg)
 113                 scatterwalk_sg_chain(head, 2, sg);
 114         else
 115                 sg_mark_end(head);
 116 }
 117
 118 static void authenc_geniv_ahash_update_done(struct crypto_async_request *areq,
 119                                             int err)
 120 {
 121         struct aead_request *req = areq->data;
 122         struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 123         struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
 124         struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
 125         struct ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
 126
 127         if (err)
 128                 goto out;
 129
 130         ahash_request_set_crypt(ahreq, areq_ctx->sg, ahreq->result,
 131                                 areq_ctx->cryptlen);
 132         ahash_request_set_callback(ahreq, aead_request_flags(req) &
 133                                           CRYPTO_TFM_REQ_MAY_SLEEP,
 134                                    areq_ctx->complete, req);
 135
 136         err = crypto_ahash_finup(ahreq);
 137         if (err)
 138                 goto out;
 139
 140         scatterwalk_map_and_copy(ahreq->result, areq_ctx->sg,
 141                                  areq_ctx->cryptlen,
 142                                  crypto_aead_authsize(authenc), 1);
 143
 144 out:
 145         aead_request_complete(req, err);
 146 }
 147
 148 static void authenc_geniv_ahash_done(struct crypto_async_request *areq, int err)
 149 {
 150         struct aead_request *req = areq->data;
 151         struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 152         struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
 153         struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
 154         struct ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
 155
 156         if (err)
 157                 goto out;
 158
 159         scatterwalk_map_and_copy(ahreq->result, areq_ctx->sg,
 160                                  areq_ctx->cryptlen,
 161                                  crypto_aead_authsize(authenc), 1);
 162
 163 out:
 164         aead_request_complete(req, err);
 165 }
 166
 167 static void authenc_verify_ahash_update_done(struct crypto_async_request *areq,
 168                                              int err)
 169 {
 170         u8 *ihash;
 171         unsigned int authsize;
 172         struct ablkcipher_request *abreq;
 173         struct aead_request *req = areq->data;
 174         struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 175         struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
 176         struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
 177         struct ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
 178
 179         if (err)
 180                 goto out;
 181
 182         ahash_request_set_crypt(ahreq, areq_ctx->sg, ahreq->result,
 183                                 areq_ctx->cryptlen);
 184         ahash_request_set_callback(ahreq, aead_request_flags(req) &
 185                                           CRYPTO_TFM_REQ_MAY_SLEEP,
 186                                    areq_ctx->complete, req);
 187
 188         err = crypto_ahash_finup(ahreq);
 189         if (err)
 190                 goto out;
 191
 192         authsize = crypto_aead_authsize(authenc);
 193         ihash = ahreq->result + authsize;
 194         scatterwalk_map_and_copy(ihash, areq_ctx->sg, areq_ctx->cryptlen,
 195                                  authsize, 0);
 196
 197         err = memcmp(ihash, ahreq->result, authsize) ? -EBADMSG : 0;
 198         if (err)
 199                 goto out;
 200
 201         abreq = aead_request_ctx(req);
 202         ablkcipher_request_set_tfm(abreq, ctx->enc);
 203         ablkcipher_request_set_callback(abreq, aead_request_flags(req),
 204                                         req->base.complete, req->base.data);
 205         ablkcipher_request_set_crypt(abreq, req->src, req->dst,
 206                                      req->cryptlen, req->iv);
 207
 208         err = crypto_ablkcipher_decrypt(abreq);
 209
 210 out:
 211         aead_request_complete(req, err);
 212 }
 213
 214 static void authenc_verify_ahash_done(struct crypto_async_request *areq,
 215                                       int err)
 216 {
 217         u8 *ihash;
 218         unsigned int authsize;
 219         struct ablkcipher_request *abreq;
 220         struct aead_request *req = areq->data;
 221         struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 222         struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
 223         struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
 224         struct ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
 225
 226         if (err)
 227                 goto out;
 228
 229         authsize = crypto_aead_authsize(authenc);
 230         ihash = ahreq->result + authsize;
 231         scatterwalk_map_and_copy(ihash, areq_ctx->sg, areq_ctx->cryptlen,
 232                                  authsize, 0);
 233
 234         err = memcmp(ihash, ahreq->result, authsize) ? -EBADMSG : 0;
 235         if (err)
 236                 goto out;
 237
 238         abreq = aead_request_ctx(req);
 239         ablkcipher_request_set_tfm(abreq, ctx->enc);
 240         ablkcipher_request_set_callback(abreq, aead_request_flags(req),
 241                                         req->base.complete, req->base.data);
 242         ablkcipher_request_set_crypt(abreq, req->src, req->dst,
 243                                      req->cryptlen, req->iv);
 244
 245         err = crypto_ablkcipher_decrypt(abreq);
 246
 247 out:
 248         aead_request_complete(req, err);
 249 }
 250
 251 static u8 *crypto_authenc_ahash_fb(struct aead_request *req, unsigned int flags)
 252 {
 253         struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 254         struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
 255         struct crypto_ahash *auth = ctx->auth;
 256         struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
 257         struct ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
 258         u8 *hash = areq_ctx->tail;
 259         int err;
 260
 261         hash = (u8 *)ALIGN((unsigned long)hash + crypto_ahash_alignmask(auth),
 262                             crypto_ahash_alignmask(auth) + 1);
 263
 264         ahash_request_set_tfm(ahreq, auth);
 265
 266         err = crypto_ahash_init(ahreq);
 267         if (err)
 268                 return ERR_PTR(err);
 269
 270         ahash_request_set_crypt(ahreq, req->assoc, hash, req->assoclen);
 271         ahash_request_set_callback(ahreq, aead_request_flags(req) & flags,
 272                                    areq_ctx->update_complete, req);
 273
 274         err = crypto_ahash_update(ahreq);
 275         if (err)
 276                 return ERR_PTR(err);
 277
 278         ahash_request_set_crypt(ahreq, areq_ctx->sg, hash,
 279                                 areq_ctx->cryptlen);
 280         ahash_request_set_callback(ahreq, aead_request_flags(req) & flags,
 281                                    areq_ctx->complete, req);
 282
 283         err = crypto_ahash_finup(ahreq);
 284         if (err)
 285                 return ERR_PTR(err);
 286
 287         return hash;
 288 }
 289
 290 static u8 *crypto_authenc_ahash(struct aead_request *req, unsigned int flags)
 291 {
 292         struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 293         struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
 294         struct crypto_ahash *auth = ctx->auth;
 295         struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
 296         struct ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
 297         u8 *hash = areq_ctx->tail;
 298         int err;
 299
 300         hash = (u8 *)ALIGN((unsigned long)hash + crypto_ahash_alignmask(auth),
 301                            crypto_ahash_alignmask(auth) + 1);
 302
 303         ahash_request_set_tfm(ahreq, auth);
 304         ahash_request_set_crypt(ahreq, areq_ctx->sg, hash,
 305                                 areq_ctx->cryptlen);
 306         ahash_request_set_callback(ahreq, aead_request_flags(req) & flags,
 307                                    areq_ctx->complete, req);
 308
 309         err = crypto_ahash_digest(ahreq);
 310         if (err)
 311                 return ERR_PTR(err);
 312
 313         return hash;
 314 }
 315
 316 static int crypto_authenc_genicv(struct aead_request *req, u8 *iv,
 317                                  unsigned int flags)
 318 {
 319         struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 320         struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
 321         struct scatterlist *dst = req->dst;
 322         struct scatterlist *assoc = req->assoc;
 323         struct scatterlist *cipher = areq_ctx->cipher;
 324         struct scatterlist *asg = areq_ctx->asg;
 325         unsigned int ivsize = crypto_aead_ivsize(authenc);
 326         unsigned int cryptlen = req->cryptlen;
 327         authenc_ahash_t authenc_ahash_fn = crypto_authenc_ahash_fb;
 328         struct page *dstp;
 329         u8 *vdst;
 330         u8 *hash;
 331
 332         dstp = sg_page(dst);
 333         vdst = PageHighMem(dstp) ? NULL : page_address(dstp) + dst->offset;
 334
 335         if (ivsize) {
 336                 sg_init_table(cipher, 2);
 337                 sg_set_buf(cipher, iv, ivsize);
 338                 authenc_chain(cipher, dst, vdst == iv + ivsize);
 339                 dst = cipher;
 340                 cryptlen += ivsize;
 341         }
 342
 343         if (sg_is_last(assoc)) {
 344                 authenc_ahash_fn = crypto_authenc_ahash;
 345                 sg_init_table(asg, 2);
 346                 sg_set_page(asg, sg_page(assoc), assoc->length, assoc->offset);
 347                 authenc_chain(asg, dst, 0);
 348                 dst = asg;
 349                 cryptlen += req->assoclen;
 350         }
 351
 352         areq_ctx->cryptlen = cryptlen;
 353         areq_ctx->sg = dst;
 354
 355         areq_ctx->complete = authenc_geniv_ahash_done;
 356         areq_ctx->update_complete = authenc_geniv_ahash_update_done;
 357
 358         hash = authenc_ahash_fn(req, flags);
 359         if (IS_ERR(hash))
 360                 return PTR_ERR(hash);
 361
 362         scatterwalk_map_and_copy(hash, dst, cryptlen,
 363                                  crypto_aead_authsize(authenc), 1);
 364         return 0;
 365 }
 366
 367 static void crypto_authenc_encrypt_done(struct crypto_async_request *req,
 368                                         int err)
 369 {
 370         struct aead_request *areq = req->data;
 371
 372         if (!err) {
 373                 struct crypto_aead *authenc = crypto_aead_reqtfm(areq);
 374                 struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
 375                 struct ablkcipher_request *abreq = aead_request_ctx(areq);
 376                 u8 *iv = (u8 *)(abreq + 1) +
 377                          crypto_ablkcipher_reqsize(ctx->enc);
 378
 379                 err = crypto_authenc_genicv(areq, iv, 0);
 380         }
 381
 382         aead_request_complete(areq, err);
 383 }
 384
 385 static int crypto_authenc_encrypt(struct aead_request *req)
 386 {
 387         struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 388         struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
 389         struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
 390         struct crypto_ablkcipher *enc = ctx->enc;
 391         struct scatterlist *dst = req->dst;
 392         unsigned int cryptlen = req->cryptlen;
 393         struct ablkcipher_request *abreq = (void *)(areq_ctx->tail
 394                                                     + ctx->reqoff);
 395         u8 *iv = (u8 *)abreq - crypto_ablkcipher_ivsize(enc);
 396         int err;
 397
 398         ablkcipher_request_set_tfm(abreq, enc);
 399         ablkcipher_request_set_callback(abreq, aead_request_flags(req),
 400                                         crypto_authenc_encrypt_done, req);
 401         ablkcipher_request_set_crypt(abreq, req->src, dst, cryptlen, req->iv);
 402
 403         memcpy(iv, req->iv, crypto_aead_ivsize(authenc));
 404
 405         err = crypto_ablkcipher_encrypt(abreq);
 406         if (err)
 407                 return err;
 408
 409         return crypto_authenc_genicv(req, iv, CRYPTO_TFM_REQ_MAY_SLEEP);
 410 }
 411
 412 static void crypto_authenc_givencrypt_done(struct crypto_async_request *req,
 413                                            int err)
 414 {
 415         struct aead_request *areq = req->data;
 416
 417         if (!err) {
 418                 struct skcipher_givcrypt_request *greq = aead_request_ctx(areq);
 419
 420                 err = crypto_authenc_genicv(areq, greq->giv, 0);
 421         }
 422
 423         aead_request_complete(areq, err);
 424 }
 425
 426 static int crypto_authenc_givencrypt(struct aead_givcrypt_request *req)
 427 {
 428         struct crypto_aead *authenc = aead_givcrypt_reqtfm(req);
 429         struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
 430         struct aead_request *areq = &req->areq;
 431         struct skcipher_givcrypt_request *greq = aead_request_ctx(areq);
 432         u8 *iv = req->giv;
 433         int err;
 434
 435         skcipher_givcrypt_set_tfm(greq, ctx->enc);
 436         skcipher_givcrypt_set_callback(greq, aead_request_flags(areq),
 437                                        crypto_authenc_givencrypt_done, areq);
 438         skcipher_givcrypt_set_crypt(greq, areq->src, areq->dst, areq->cryptlen,
 439                                     areq->iv);
 440         skcipher_givcrypt_set_giv(greq, iv, req->seq);
 441
 442         err = crypto_skcipher_givencrypt(greq);
 443         if (err)
 444                 return err;
 445
 446         return crypto_authenc_genicv(areq, iv, CRYPTO_TFM_REQ_MAY_SLEEP);
 447 }
 448
 449 static int crypto_authenc_verify(struct aead_request *req,
 450                                  authenc_ahash_t authenc_ahash_fn)
 451 {
 452         struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 453         struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
 454         u8 *ohash;
 455         u8 *ihash;
 456         unsigned int authsize;
 457
 458         areq_ctx->complete = authenc_verify_ahash_done;
 459         areq_ctx->update_complete = authenc_verify_ahash_update_done;
 460
 461         ohash = authenc_ahash_fn(req, CRYPTO_TFM_REQ_MAY_SLEEP);
 462         if (IS_ERR(ohash))
 463                 return PTR_ERR(ohash);
 464
 465         authsize = crypto_aead_authsize(authenc);
 466         ihash = ohash + authsize;
 467         scatterwalk_map_and_copy(ihash, areq_ctx->sg, areq_ctx->cryptlen,
 468                                  authsize, 0);
 469         return memcmp(ihash, ohash, authsize) ? -EBADMSG : 0;
 470 }
 471
 472 static int crypto_authenc_iverify(struct aead_request *req, u8 *iv,
 473                                   unsigned int cryptlen)
 474 {
 475         struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 476         struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
 477         struct scatterlist *src = req->src;
 478         struct scatterlist *assoc = req->assoc;
 479         struct scatterlist *cipher = areq_ctx->cipher;
 480         struct scatterlist *asg = areq_ctx->asg;
 481         unsigned int ivsize = crypto_aead_ivsize(authenc);
 482         authenc_ahash_t authenc_ahash_fn = crypto_authenc_ahash_fb;
 483         struct page *srcp;
 484         u8 *vsrc;
 485
 486         srcp = sg_page(src);
 487         vsrc = PageHighMem(srcp) ? NULL : page_address(srcp) + src->offset;
 488
 489         if (ivsize) {
 490                 sg_init_table(cipher, 2);
 491                 sg_set_buf(cipher, iv, ivsize);
 492                 authenc_chain(cipher, src, vsrc == iv + ivsize);
 493                 src = cipher;
 494                 cryptlen += ivsize;
 495         }
 496
 497         if (sg_is_last(assoc)) {
 498                 authenc_ahash_fn = crypto_authenc_ahash;
 499                 sg_init_table(asg, 2);
 500                 sg_set_page(asg, sg_page(assoc), assoc->length, assoc->offset);
 501                 authenc_chain(asg, src, 0);
 502                 src = asg;
 503                 cryptlen += req->assoclen;
 504         }
 505
 506         areq_ctx->cryptlen = cryptlen;
 507         areq_ctx->sg = src;
 508
 509         return crypto_authenc_verify(req, authenc_ahash_fn);
 510 }
 511
 512 static int crypto_authenc_decrypt(struct aead_request *req)
 513 {
 514         struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 515         struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
 516         struct ablkcipher_request *abreq = aead_request_ctx(req);
 517         unsigned int cryptlen = req->cryptlen;
 518         unsigned int authsize = crypto_aead_authsize(authenc);
 519         u8 *iv = req->iv;
 520         int err;
 521
 522         if (cryptlen < authsize)
 523                 return -EINVAL;
 524         cryptlen -= authsize;
 525
 526         err = crypto_authenc_iverify(req, iv, cryptlen);
 527         if (err)
 528                 return err;
 529
 530         ablkcipher_request_set_tfm(abreq, ctx->enc);
 531         ablkcipher_request_set_callback(abreq, aead_request_flags(req),
 532                                         req->base.complete, req->base.data);
 533         ablkcipher_request_set_crypt(abreq, req->src, req->dst, cryptlen, iv);
 534
 535         return crypto_ablkcipher_decrypt(abreq);
 536 }
 537
 538 static int crypto_authenc_init_tfm(struct crypto_tfm *tfm)
 539 {
 540         struct crypto_instance *inst = crypto_tfm_alg_instance(tfm);
 541         struct authenc_instance_ctx *ictx = crypto_instance_ctx(inst);
 542         struct crypto_authenc_ctx *ctx = crypto_tfm_ctx(tfm);
 543         struct crypto_ahash *auth;
 544         struct crypto_ablkcipher *enc;
 545         int err;
 546
 547         auth = crypto_spawn_ahash(&ictx->auth);
 548         if (IS_ERR(auth))
 549                 return PTR_ERR(auth);
 550
 551         enc = crypto_spawn_skcipher(&ictx->enc);
 552         err = PTR_ERR(enc);
 553         if (IS_ERR(enc))
 554                 goto err_free_ahash;
 555
 556         ctx->auth = auth;
 557         ctx->enc = enc;
 558
 559         ctx->reqoff = ALIGN(2 * crypto_ahash_digestsize(auth) +
 560                             crypto_ahash_alignmask(auth),
 561                             crypto_ahash_alignmask(auth) + 1) +
 562                       crypto_ablkcipher_ivsize(enc);
 563
 564         tfm->crt_aead.reqsize = sizeof(struct authenc_request_ctx) +
 565                                 ctx->reqoff +
 566                                 max_t(unsigned int,
 567                                 crypto_ahash_reqsize(auth) +
 568                                 sizeof(struct ahash_request),
 569                                 sizeof(struct skcipher_givcrypt_request) +
 570                                 crypto_ablkcipher_reqsize(enc));
 571
 572         return 0;
 573
 574 err_free_ahash:
 575         crypto_free_ahash(auth);
 576         return err;
 577 }
 578
 579 static void crypto_authenc_exit_tfm(struct crypto_tfm *tfm)
 580 {
 581         struct crypto_authenc_ctx *ctx = crypto_tfm_ctx(tfm);
 582
 583         crypto_free_ahash(ctx->auth);
 584         crypto_free_ablkcipher(ctx->enc);
 585 }
 586
 587 static struct crypto_instance *crypto_authenc_alloc(struct rtattr **tb)
 588 {
 589         struct crypto_attr_type *algt;
 590         struct crypto_instance *inst;
 591         struct hash_alg_common *auth;
 592         struct crypto_alg *auth_base;
 593         struct crypto_alg *enc;
 594         struct authenc_instance_ctx *ctx;
 595         const char *enc_name;
 596         int err;
 597
 598         algt = crypto_get_attr_type(tb);
 599         err = PTR_ERR(algt);
 600         if (IS_ERR(algt))
 601                 return ERR_PTR(err);
 602
 603         if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
 604                 return ERR_PTR(-EINVAL);
 605
 606         auth = ahash_attr_alg(tb[1], CRYPTO_ALG_TYPE_HASH,
 607                                CRYPTO_ALG_TYPE_AHASH_MASK);
 608         if (IS_ERR(auth))
 609                 return ERR_PTR(PTR_ERR(auth));
 610
 611         auth_base = &auth->base;
 612
 613         enc_name = crypto_attr_alg_name(tb[2]);
 614         err = PTR_ERR(enc_name);
 615         if (IS_ERR(enc_name))
 616                 goto out_put_auth;
 617
 618         inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
 619         err = -ENOMEM;
 620         if (!inst)
 621                 goto out_put_auth;
 622
 623         ctx = crypto_instance_ctx(inst);
 624
 625         err = crypto_init_ahash_spawn(&ctx->auth, auth, inst);
 626         if (err)
 627                 goto err_free_inst;
 628
 629         crypto_set_skcipher_spawn(&ctx->enc, inst);
 630         err = crypto_grab_skcipher(&ctx->enc, enc_name, 0,
 631                                    crypto_requires_sync(algt->type,
 632                                                         algt->mask));
 633         if (err)
 634                 goto err_drop_auth;
 635
 636         enc = crypto_skcipher_spawn_alg(&ctx->enc);
 637
 638         err = -ENAMETOOLONG;
 639         if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME,
 640                      "authenc(%s,%s)", auth_base->cra_name, enc->cra_name) >=
 641             CRYPTO_MAX_ALG_NAME)
 642                 goto err_drop_enc;
 643
 644         if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
 645                      "authenc(%s,%s)", auth_base->cra_driver_name,
 646                      enc->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
 647                 goto err_drop_enc;
 648
 649         inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD;
 650         inst->alg.cra_flags |= enc->cra_flags & CRYPTO_ALG_ASYNC;
 651         inst->alg.cra_priority = enc->cra_priority *
 652                                  10 + auth_base->cra_priority;
 653         inst->alg.cra_blocksize = enc->cra_blocksize;
 654         inst->alg.cra_alignmask = auth_base->cra_alignmask | enc->cra_alignmask;
 655         inst->alg.cra_type = &crypto_aead_type;
 656
 657         inst->alg.cra_aead.ivsize = enc->cra_ablkcipher.ivsize;
 658         inst->alg.cra_aead.maxauthsize = auth->digestsize;
 659
 660         inst->alg.cra_ctxsize = sizeof(struct crypto_authenc_ctx);
 661
 662         inst->alg.cra_init = crypto_authenc_init_tfm;
 663         inst->alg.cra_exit = crypto_authenc_exit_tfm;
 664
 665         inst->alg.cra_aead.setkey = crypto_authenc_setkey;
 666         inst->alg.cra_aead.encrypt = crypto_authenc_encrypt;
 667         inst->alg.cra_aead.decrypt = crypto_authenc_decrypt;
 668         inst->alg.cra_aead.givencrypt = crypto_authenc_givencrypt;
 669
 670 out:
 671         crypto_mod_put(auth_base);
 672         return inst;
 673
 674 err_drop_enc:
 675         crypto_drop_skcipher(&ctx->enc);
 676 err_drop_auth:
 677         crypto_drop_ahash(&ctx->auth);
 678 err_free_inst:
 679         kfree(inst);
 680 out_put_auth:
 681         inst = ERR_PTR(err);
 682         goto out;
 683 }
 684
 685 static void crypto_authenc_free(struct crypto_instance *inst)
 686 {
 687         struct authenc_instance_ctx *ctx = crypto_instance_ctx(inst);
 688
 689         crypto_drop_skcipher(&ctx->enc);
 690         crypto_drop_ahash(&ctx->auth);
 691         kfree(inst);
 692 }
 693
 694 static struct crypto_template crypto_authenc_tmpl = {
 695         .name = "authenc",
 696         .alloc = crypto_authenc_alloc,
 697         .free = crypto_authenc_free,
 698         .module = THIS_MODULE,
 699 };
 700
 701 static int __init crypto_authenc_module_init(void)
 702 {
 703         return crypto_register_template(&crypto_authenc_tmpl);
 704 }
 705
 706 static void __exit crypto_authenc_module_exit(void)
 707 {
 708         crypto_unregister_template(&crypto_authenc_tmpl);
 709 }
 710
 711 module_init(crypto_authenc_module_init);
 712 module_exit(crypto_authenc_module_exit);
 713
 714 MODULE_LICENSE("GPL");
 715 MODULE_DESCRIPTION("Simple AEAD wrapper for IPsec");