crypto/authencesn.c

   1 /*
   2  * authencesn.c - AEAD wrapper for IPsec with extended sequence numbers,
   3  *                 derived from authenc.c
   4  *
   5  * Copyright (C) 2010 secunet Security Networks AG
   6  * Copyright (C) 2010 Steffen Klassert <steffen.klassert@secunet.com>
   7  *
   8  * This program is free software; you can redistribute it and/or modify it
   9  * under the terms of the GNU General Public License as published by the Free
  10  * Software Foundation; either version 2 of the License, or (at your option)
  11  * any later version.
  12  *
  13  */
  14
  15 #include <crypto/aead.h>
  16 #include <crypto/internal/hash.h>
  17 #include <crypto/internal/skcipher.h>
  18 #include <crypto/authenc.h>
  19 #include <crypto/scatterwalk.h>
  20 #include <linux/err.h>
  21 #include <linux/init.h>
  22 #include <linux/kernel.h>
  23 #include <linux/module.h>
  24 #include <linux/rtnetlink.h>
  25 #include <linux/slab.h>
  26 #include <linux/spinlock.h>
  27
  28 struct authenc_esn_instance_ctx {
  29         struct crypto_ahash_spawn auth;
  30         struct crypto_skcipher_spawn enc;
  31 };
  32
  33 struct crypto_authenc_esn_ctx {
  34         unsigned int reqoff;
  35         struct crypto_ahash *auth;
  36         struct crypto_ablkcipher *enc;
  37 };
  38
  39 struct authenc_esn_request_ctx {
  40         unsigned int cryptlen;
  41         unsigned int headlen;
  42         unsigned int trailen;
  43         struct scatterlist *sg;
  44         struct scatterlist hsg[2];
  45         struct scatterlist tsg[1];
  46         struct scatterlist cipher[2];
  47         crypto_completion_t complete;
  48         crypto_completion_t update_complete;
  49         crypto_completion_t update_complete2;
  50         char tail[];
  51 };
  52
  53 static void authenc_esn_request_complete(struct aead_request *req, int err)
  54 {
  55         if (err != -EINPROGRESS)
  56                 aead_request_complete(req, err);
  57 }
  58
  59 static int crypto_authenc_esn_setkey(struct crypto_aead *authenc_esn, const u8 *key,
  60                                      unsigned int keylen)
  61 {
  62         unsigned int authkeylen;
  63         unsigned int enckeylen;
  64         struct crypto_authenc_esn_ctx *ctx = crypto_aead_ctx(authenc_esn);
  65         struct crypto_ahash *auth = ctx->auth;
  66         struct crypto_ablkcipher *enc = ctx->enc;
  67         struct rtattr *rta = (void *)key;
  68         struct crypto_authenc_key_param *param;
  69         int err = -EINVAL;
  70
  71         if (!RTA_OK(rta, keylen))
  72                 goto badkey;
  73         if (rta->rta_type != CRYPTO_AUTHENC_KEYA_PARAM)
  74                 goto badkey;
  75         if (RTA_PAYLOAD(rta) < sizeof(*param))
  76                 goto badkey;
  77
  78         param = RTA_DATA(rta);
  79         enckeylen = be32_to_cpu(param->enckeylen);
  80
  81         key += RTA_ALIGN(rta->rta_len);
  82         keylen -= RTA_ALIGN(rta->rta_len);
  83
  84         if (keylen < enckeylen)
  85                 goto badkey;
  86
  87         authkeylen = keylen - enckeylen;
  88
  89         crypto_ahash_clear_flags(auth, CRYPTO_TFM_REQ_MASK);
  90         crypto_ahash_set_flags(auth, crypto_aead_get_flags(authenc_esn) &
  91                                      CRYPTO_TFM_REQ_MASK);
  92         err = crypto_ahash_setkey(auth, key, authkeylen);
  93         crypto_aead_set_flags(authenc_esn, crypto_ahash_get_flags(auth) &
  94                                            CRYPTO_TFM_RES_MASK);
  95
  96         if (err)
  97                 goto out;
  98
  99         crypto_ablkcipher_clear_flags(enc, CRYPTO_TFM_REQ_MASK);
 100         crypto_ablkcipher_set_flags(enc, crypto_aead_get_flags(authenc_esn) &
 101                                          CRYPTO_TFM_REQ_MASK);
 102         err = crypto_ablkcipher_setkey(enc, key + authkeylen, enckeylen);
 103         crypto_aead_set_flags(authenc_esn, crypto_ablkcipher_get_flags(enc) &
 104                                            CRYPTO_TFM_RES_MASK);
 105
 106 out:
 107         return err;
 108
 109 badkey:
 110         crypto_aead_set_flags(authenc_esn, CRYPTO_TFM_RES_BAD_KEY_LEN);
 111         goto out;
 112 }
 113
 114 static void authenc_esn_geniv_ahash_update_done(struct crypto_async_request *areq,
 115                                                 int err)
 116 {
 117         struct aead_request *req = areq->data;
 118         struct crypto_aead *authenc_esn = crypto_aead_reqtfm(req);
 119         struct crypto_authenc_esn_ctx *ctx = crypto_aead_ctx(authenc_esn);
 120         struct authenc_esn_request_ctx *areq_ctx = aead_request_ctx(req);
 121         struct ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
 122
 123         if (err)
 124                 goto out;
 125
 126         ahash_request_set_crypt(ahreq, areq_ctx->sg, ahreq->result,
 127                                 areq_ctx->cryptlen);
 128         ahash_request_set_callback(ahreq, aead_request_flags(req) &
 129                                           CRYPTO_TFM_REQ_MAY_SLEEP,
 130                                    areq_ctx->update_complete2, req);
 131
 132         err = crypto_ahash_update(ahreq);
 133         if (err)
 134                 goto out;
 135
 136         ahash_request_set_crypt(ahreq, areq_ctx->tsg, ahreq->result,
 137                                 areq_ctx->trailen);
 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_esn), 1);
 149
 150 out:
 151         authenc_esn_request_complete(req, err);
 152 }
 153
 154 static void authenc_esn_geniv_ahash_update_done2(struct crypto_async_request *areq,
 155                                                  int err)
 156 {
 157         struct aead_request *req = areq->data;
 158         struct crypto_aead *authenc_esn = crypto_aead_reqtfm(req);
 159         struct crypto_authenc_esn_ctx *ctx = crypto_aead_ctx(authenc_esn);
 160         struct authenc_esn_request_ctx *areq_ctx = aead_request_ctx(req);
 161         struct ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
 162
 163         if (err)
 164                 goto out;
 165
 166         ahash_request_set_crypt(ahreq, areq_ctx->tsg, ahreq->result,
 167                                 areq_ctx->trailen);
 168         ahash_request_set_callback(ahreq, aead_request_flags(req) &
 169                                           CRYPTO_TFM_REQ_MAY_SLEEP,
 170                                    areq_ctx->complete, req);
 171
 172         err = crypto_ahash_finup(ahreq);
 173         if (err)
 174                 goto out;
 175
 176         scatterwalk_map_and_copy(ahreq->result, areq_ctx->sg,
 177                                  areq_ctx->cryptlen,
 178                                  crypto_aead_authsize(authenc_esn), 1);
 179
 180 out:
 181         authenc_esn_request_complete(req, err);
 182 }
 183
 184
 185 static void authenc_esn_geniv_ahash_done(struct crypto_async_request *areq,
 186                                          int err)
 187 {
 188         struct aead_request *req = areq->data;
 189         struct crypto_aead *authenc_esn = crypto_aead_reqtfm(req);
 190         struct crypto_authenc_esn_ctx *ctx = crypto_aead_ctx(authenc_esn);
 191         struct authenc_esn_request_ctx *areq_ctx = aead_request_ctx(req);
 192         struct ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
 193
 194         if (err)
 195                 goto out;
 196
 197         scatterwalk_map_and_copy(ahreq->result, areq_ctx->sg,
 198                                  areq_ctx->cryptlen,
 199                                  crypto_aead_authsize(authenc_esn), 1);
 200
 201 out:
 202         aead_request_complete(req, err);
 203 }
 204
 205
 206 static void authenc_esn_verify_ahash_update_done(struct crypto_async_request *areq,
 207                                                  int err)
 208 {
 209         u8 *ihash;
 210         unsigned int authsize;
 211         struct ablkcipher_request *abreq;
 212         struct aead_request *req = areq->data;
 213         struct crypto_aead *authenc_esn = crypto_aead_reqtfm(req);
 214         struct crypto_authenc_esn_ctx *ctx = crypto_aead_ctx(authenc_esn);
 215         struct authenc_esn_request_ctx *areq_ctx = aead_request_ctx(req);
 216         struct ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
 217         unsigned int cryptlen = req->cryptlen;
 218
 219         if (err)
 220                 goto out;
 221
 222         ahash_request_set_crypt(ahreq, areq_ctx->sg, ahreq->result,
 223                                 areq_ctx->cryptlen);
 224
 225         ahash_request_set_callback(ahreq,
 226                                    aead_request_flags(req) &
 227                                    CRYPTO_TFM_REQ_MAY_SLEEP,
 228                                    areq_ctx->update_complete2, req);
 229
 230         err = crypto_ahash_update(ahreq);
 231         if (err)
 232                 goto out;
 233
 234         ahash_request_set_crypt(ahreq, areq_ctx->tsg, ahreq->result,
 235                                 areq_ctx->trailen);
 236         ahash_request_set_callback(ahreq, aead_request_flags(req) &
 237                                           CRYPTO_TFM_REQ_MAY_SLEEP,
 238                                    areq_ctx->complete, req);
 239
 240         err = crypto_ahash_finup(ahreq);
 241         if (err)
 242                 goto out;
 243
 244         authsize = crypto_aead_authsize(authenc_esn);
 245         cryptlen -= authsize;
 246         ihash = ahreq->result + authsize;
 247         scatterwalk_map_and_copy(ihash, areq_ctx->sg, areq_ctx->cryptlen,
 248                                  authsize, 0);
 249
 250         err = memcmp(ihash, ahreq->result, authsize) ? -EBADMSG : 0;
 251         if (err)
 252                 goto out;
 253
 254         abreq = aead_request_ctx(req);
 255         ablkcipher_request_set_tfm(abreq, ctx->enc);
 256         ablkcipher_request_set_callback(abreq, aead_request_flags(req),
 257                                         req->base.complete, req->base.data);
 258         ablkcipher_request_set_crypt(abreq, req->src, req->dst,
 259                                      cryptlen, req->iv);
 260
 261         err = crypto_ablkcipher_decrypt(abreq);
 262
 263 out:
 264         authenc_esn_request_complete(req, err);
 265 }
 266
 267 static void authenc_esn_verify_ahash_update_done2(struct crypto_async_request *areq,
 268                                                   int err)
 269 {
 270         u8 *ihash;
 271         unsigned int authsize;
 272         struct ablkcipher_request *abreq;
 273         struct aead_request *req = areq->data;
 274         struct crypto_aead *authenc_esn = crypto_aead_reqtfm(req);
 275         struct crypto_authenc_esn_ctx *ctx = crypto_aead_ctx(authenc_esn);
 276         struct authenc_esn_request_ctx *areq_ctx = aead_request_ctx(req);
 277         struct ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
 278         unsigned int cryptlen = req->cryptlen;
 279
 280         if (err)
 281                 goto out;
 282
 283         ahash_request_set_crypt(ahreq, areq_ctx->tsg, ahreq->result,
 284                                 areq_ctx->trailen);
 285         ahash_request_set_callback(ahreq, aead_request_flags(req) &
 286                                           CRYPTO_TFM_REQ_MAY_SLEEP,
 287                                    areq_ctx->complete, req);
 288
 289         err = crypto_ahash_finup(ahreq);
 290         if (err)
 291                 goto out;
 292
 293         authsize = crypto_aead_authsize(authenc_esn);
 294         cryptlen -= authsize;
 295         ihash = ahreq->result + authsize;
 296         scatterwalk_map_and_copy(ihash, areq_ctx->sg, areq_ctx->cryptlen,
 297                                  authsize, 0);
 298
 299         err = memcmp(ihash, ahreq->result, authsize) ? -EBADMSG : 0;
 300         if (err)
 301                 goto out;
 302
 303         abreq = aead_request_ctx(req);
 304         ablkcipher_request_set_tfm(abreq, ctx->enc);
 305         ablkcipher_request_set_callback(abreq, aead_request_flags(req),
 306                                         req->base.complete, req->base.data);
 307         ablkcipher_request_set_crypt(abreq, req->src, req->dst,
 308                                      cryptlen, req->iv);
 309
 310         err = crypto_ablkcipher_decrypt(abreq);
 311
 312 out:
 313         authenc_esn_request_complete(req, err);
 314 }
 315
 316
 317 static void authenc_esn_verify_ahash_done(struct crypto_async_request *areq,
 318                                           int err)
 319 {
 320         u8 *ihash;
 321         unsigned int authsize;
 322         struct ablkcipher_request *abreq;
 323         struct aead_request *req = areq->data;
 324         struct crypto_aead *authenc_esn = crypto_aead_reqtfm(req);
 325         struct crypto_authenc_esn_ctx *ctx = crypto_aead_ctx(authenc_esn);
 326         struct authenc_esn_request_ctx *areq_ctx = aead_request_ctx(req);
 327         struct ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
 328         unsigned int cryptlen = req->cryptlen;
 329
 330         if (err)
 331                 goto out;
 332
 333         authsize = crypto_aead_authsize(authenc_esn);
 334         cryptlen -= authsize;
 335         ihash = ahreq->result + authsize;
 336         scatterwalk_map_and_copy(ihash, areq_ctx->sg, areq_ctx->cryptlen,
 337                                  authsize, 0);
 338
 339         err = memcmp(ihash, ahreq->result, authsize) ? -EBADMSG : 0;
 340         if (err)
 341                 goto out;
 342
 343         abreq = aead_request_ctx(req);
 344         ablkcipher_request_set_tfm(abreq, ctx->enc);
 345         ablkcipher_request_set_callback(abreq, aead_request_flags(req),
 346                                         req->base.complete, req->base.data);
 347         ablkcipher_request_set_crypt(abreq, req->src, req->dst,
 348                                      cryptlen, req->iv);
 349
 350         err = crypto_ablkcipher_decrypt(abreq);
 351
 352 out:
 353         authenc_esn_request_complete(req, err);
 354 }
 355
 356 static u8 *crypto_authenc_esn_ahash(struct aead_request *req,
 357                                     unsigned int flags)
 358 {
 359         struct crypto_aead *authenc_esn = crypto_aead_reqtfm(req);
 360         struct crypto_authenc_esn_ctx *ctx = crypto_aead_ctx(authenc_esn);
 361         struct crypto_ahash *auth = ctx->auth;
 362         struct authenc_esn_request_ctx *areq_ctx = aead_request_ctx(req);
 363         struct ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
 364         u8 *hash = areq_ctx->tail;
 365         int err;
 366
 367         hash = (u8 *)ALIGN((unsigned long)hash + crypto_ahash_alignmask(auth),
 368                             crypto_ahash_alignmask(auth) + 1);
 369
 370         ahash_request_set_tfm(ahreq, auth);
 371
 372         err = crypto_ahash_init(ahreq);
 373         if (err)
 374                 return ERR_PTR(err);
 375
 376         ahash_request_set_crypt(ahreq, areq_ctx->hsg, hash, areq_ctx->headlen);
 377         ahash_request_set_callback(ahreq, aead_request_flags(req) & flags,
 378                                    areq_ctx->update_complete, req);
 379
 380         err = crypto_ahash_update(ahreq);
 381         if (err)
 382                 return ERR_PTR(err);
 383
 384         ahash_request_set_crypt(ahreq, areq_ctx->sg, hash, areq_ctx->cryptlen);
 385         ahash_request_set_callback(ahreq, aead_request_flags(req) & flags,
 386                                    areq_ctx->update_complete2, req);
 387
 388         err = crypto_ahash_update(ahreq);
 389         if (err)
 390                 return ERR_PTR(err);
 391
 392         ahash_request_set_crypt(ahreq, areq_ctx->tsg, hash,
 393                                 areq_ctx->trailen);
 394         ahash_request_set_callback(ahreq, aead_request_flags(req) & flags,
 395                                    areq_ctx->complete, req);
 396
 397         err = crypto_ahash_finup(ahreq);
 398         if (err)
 399                 return ERR_PTR(err);
 400
 401         return hash;
 402 }
 403
 404 static int crypto_authenc_esn_genicv(struct aead_request *req, u8 *iv,
 405                                      unsigned int flags)
 406 {
 407         struct crypto_aead *authenc_esn = crypto_aead_reqtfm(req);
 408         struct authenc_esn_request_ctx *areq_ctx = aead_request_ctx(req);
 409         struct scatterlist *dst = req->dst;
 410         struct scatterlist *assoc = req->assoc;
 411         struct scatterlist *cipher = areq_ctx->cipher;
 412         struct scatterlist *hsg = areq_ctx->hsg;
 413         struct scatterlist *tsg = areq_ctx->tsg;
 414         struct scatterlist *assoc1;
 415         struct scatterlist *assoc2;
 416         unsigned int ivsize = crypto_aead_ivsize(authenc_esn);
 417         unsigned int cryptlen = req->cryptlen;
 418         struct page *dstp;
 419         u8 *vdst;
 420         u8 *hash;
 421
 422         dstp = sg_page(dst);
 423         vdst = PageHighMem(dstp) ? NULL : page_address(dstp) + dst->offset;
 424
 425         if (ivsize) {
 426                 sg_init_table(cipher, 2);
 427                 sg_set_buf(cipher, iv, ivsize);
 428                 scatterwalk_crypto_chain(cipher, dst, vdst == iv + ivsize, 2);
 429                 dst = cipher;
 430                 cryptlen += ivsize;
 431         }
 432
 433         if (sg_is_last(assoc))
 434                 return -EINVAL;
 435
 436         assoc1 = assoc + 1;
 437         if (sg_is_last(assoc1))
 438                 return -EINVAL;
 439
 440         assoc2 = assoc + 2;
 441         if (!sg_is_last(assoc2))
 442                 return -EINVAL;
 443
 444         sg_init_table(hsg, 2);
 445         sg_set_page(hsg, sg_page(assoc), assoc->length, assoc->offset);
 446         sg_set_page(hsg + 1, sg_page(assoc2), assoc2->length, assoc2->offset);
 447
 448         sg_init_table(tsg, 1);
 449         sg_set_page(tsg, sg_page(assoc1), assoc1->length, assoc1->offset);
 450
 451         areq_ctx->cryptlen = cryptlen;
 452         areq_ctx->headlen = assoc->length + assoc2->length;
 453         areq_ctx->trailen = assoc1->length;
 454         areq_ctx->sg = dst;
 455
 456         areq_ctx->complete = authenc_esn_geniv_ahash_done;
 457         areq_ctx->update_complete = authenc_esn_geniv_ahash_update_done;
 458         areq_ctx->update_complete2 = authenc_esn_geniv_ahash_update_done2;
 459
 460         hash = crypto_authenc_esn_ahash(req, flags);
 461         if (IS_ERR(hash))
 462                 return PTR_ERR(hash);
 463
 464         scatterwalk_map_and_copy(hash, dst, cryptlen,
 465                                  crypto_aead_authsize(authenc_esn), 1);
 466         return 0;
 467 }
 468
 469
 470 static void crypto_authenc_esn_encrypt_done(struct crypto_async_request *req,
 471                                             int err)
 472 {
 473         struct aead_request *areq = req->data;
 474
 475         if (!err) {
 476                 struct crypto_aead *authenc_esn = crypto_aead_reqtfm(areq);
 477                 struct crypto_authenc_esn_ctx *ctx = crypto_aead_ctx(authenc_esn);
 478                 struct ablkcipher_request *abreq = aead_request_ctx(areq);
 479                 u8 *iv = (u8 *)(abreq + 1) +
 480                          crypto_ablkcipher_reqsize(ctx->enc);
 481
 482                 err = crypto_authenc_esn_genicv(areq, iv, 0);
 483         }
 484
 485         authenc_esn_request_complete(areq, err);
 486 }
 487
 488 static int crypto_authenc_esn_encrypt(struct aead_request *req)
 489 {
 490         struct crypto_aead *authenc_esn = crypto_aead_reqtfm(req);
 491         struct crypto_authenc_esn_ctx *ctx = crypto_aead_ctx(authenc_esn);
 492         struct authenc_esn_request_ctx *areq_ctx = aead_request_ctx(req);
 493         struct crypto_ablkcipher *enc = ctx->enc;
 494         struct scatterlist *dst = req->dst;
 495         unsigned int cryptlen = req->cryptlen;
 496         struct ablkcipher_request *abreq = (void *)(areq_ctx->tail
 497                                                     + ctx->reqoff);
 498         u8 *iv = (u8 *)abreq - crypto_ablkcipher_ivsize(enc);
 499         int err;
 500
 501         ablkcipher_request_set_tfm(abreq, enc);
 502         ablkcipher_request_set_callback(abreq, aead_request_flags(req),
 503                                         crypto_authenc_esn_encrypt_done, req);
 504         ablkcipher_request_set_crypt(abreq, req->src, dst, cryptlen, req->iv);
 505
 506         memcpy(iv, req->iv, crypto_aead_ivsize(authenc_esn));
 507
 508         err = crypto_ablkcipher_encrypt(abreq);
 509         if (err)
 510                 return err;
 511
 512         return crypto_authenc_esn_genicv(req, iv, CRYPTO_TFM_REQ_MAY_SLEEP);
 513 }
 514
 515 static void crypto_authenc_esn_givencrypt_done(struct crypto_async_request *req,
 516                                                int err)
 517 {
 518         struct aead_request *areq = req->data;
 519
 520         if (!err) {
 521                 struct skcipher_givcrypt_request *greq = aead_request_ctx(areq);
 522
 523                 err = crypto_authenc_esn_genicv(areq, greq->giv, 0);
 524         }
 525
 526         authenc_esn_request_complete(areq, err);
 527 }
 528
 529 static int crypto_authenc_esn_givencrypt(struct aead_givcrypt_request *req)
 530 {
 531         struct crypto_aead *authenc_esn = aead_givcrypt_reqtfm(req);
 532         struct crypto_authenc_esn_ctx *ctx = crypto_aead_ctx(authenc_esn);
 533         struct aead_request *areq = &req->areq;
 534         struct skcipher_givcrypt_request *greq = aead_request_ctx(areq);
 535         u8 *iv = req->giv;
 536         int err;
 537
 538         skcipher_givcrypt_set_tfm(greq, ctx->enc);
 539         skcipher_givcrypt_set_callback(greq, aead_request_flags(areq),
 540                                        crypto_authenc_esn_givencrypt_done, areq);
 541         skcipher_givcrypt_set_crypt(greq, areq->src, areq->dst, areq->cryptlen,
 542                                     areq->iv);
 543         skcipher_givcrypt_set_giv(greq, iv, req->seq);
 544
 545         err = crypto_skcipher_givencrypt(greq);
 546         if (err)
 547                 return err;
 548
 549         return crypto_authenc_esn_genicv(areq, iv, CRYPTO_TFM_REQ_MAY_SLEEP);
 550 }
 551
 552 static int crypto_authenc_esn_verify(struct aead_request *req)
 553 {
 554         struct crypto_aead *authenc_esn = crypto_aead_reqtfm(req);
 555         struct authenc_esn_request_ctx *areq_ctx = aead_request_ctx(req);
 556         u8 *ohash;
 557         u8 *ihash;
 558         unsigned int authsize;
 559
 560         areq_ctx->complete = authenc_esn_verify_ahash_done;
 561         areq_ctx->update_complete = authenc_esn_verify_ahash_update_done;
 562
 563         ohash = crypto_authenc_esn_ahash(req, CRYPTO_TFM_REQ_MAY_SLEEP);
 564         if (IS_ERR(ohash))
 565                 return PTR_ERR(ohash);
 566
 567         authsize = crypto_aead_authsize(authenc_esn);
 568         ihash = ohash + authsize;
 569         scatterwalk_map_and_copy(ihash, areq_ctx->sg, areq_ctx->cryptlen,
 570                                  authsize, 0);
 571         return memcmp(ihash, ohash, authsize) ? -EBADMSG : 0;
 572 }
 573
 574 static int crypto_authenc_esn_iverify(struct aead_request *req, u8 *iv,
 575                                       unsigned int cryptlen)
 576 {
 577         struct crypto_aead *authenc_esn = crypto_aead_reqtfm(req);
 578         struct authenc_esn_request_ctx *areq_ctx = aead_request_ctx(req);
 579         struct scatterlist *src = req->src;
 580         struct scatterlist *assoc = req->assoc;
 581         struct scatterlist *cipher = areq_ctx->cipher;
 582         struct scatterlist *hsg = areq_ctx->hsg;
 583         struct scatterlist *tsg = areq_ctx->tsg;
 584         struct scatterlist *assoc1;
 585         struct scatterlist *assoc2;
 586         unsigned int ivsize = crypto_aead_ivsize(authenc_esn);
 587         struct page *srcp;
 588         u8 *vsrc;
 589
 590         srcp = sg_page(src);
 591         vsrc = PageHighMem(srcp) ? NULL : page_address(srcp) + src->offset;
 592
 593         if (ivsize) {
 594                 sg_init_table(cipher, 2);
 595                 sg_set_buf(cipher, iv, ivsize);
 596                 scatterwalk_crypto_chain(cipher, src, vsrc == iv + ivsize, 2);
 597                 src = cipher;
 598                 cryptlen += ivsize;
 599         }
 600
 601         if (sg_is_last(assoc))
 602                 return -EINVAL;
 603
 604         assoc1 = assoc + 1;
 605         if (sg_is_last(assoc1))
 606                 return -EINVAL;
 607
 608         assoc2 = assoc + 2;
 609         if (!sg_is_last(assoc2))
 610                 return -EINVAL;
 611
 612         sg_init_table(hsg, 2);
 613         sg_set_page(hsg, sg_page(assoc), assoc->length, assoc->offset);
 614         sg_set_page(hsg + 1, sg_page(assoc2), assoc2->length, assoc2->offset);
 615
 616         sg_init_table(tsg, 1);
 617         sg_set_page(tsg, sg_page(assoc1), assoc1->length, assoc1->offset);
 618
 619         areq_ctx->cryptlen = cryptlen;
 620         areq_ctx->headlen = assoc->length + assoc2->length;
 621         areq_ctx->trailen = assoc1->length;
 622         areq_ctx->sg = src;
 623
 624         areq_ctx->complete = authenc_esn_verify_ahash_done;
 625         areq_ctx->update_complete = authenc_esn_verify_ahash_update_done;
 626         areq_ctx->update_complete2 = authenc_esn_verify_ahash_update_done2;
 627
 628         return crypto_authenc_esn_verify(req);
 629 }
 630
 631 static int crypto_authenc_esn_decrypt(struct aead_request *req)
 632 {
 633         struct crypto_aead *authenc_esn = crypto_aead_reqtfm(req);
 634         struct crypto_authenc_esn_ctx *ctx = crypto_aead_ctx(authenc_esn);
 635         struct ablkcipher_request *abreq = aead_request_ctx(req);
 636         unsigned int cryptlen = req->cryptlen;
 637         unsigned int authsize = crypto_aead_authsize(authenc_esn);
 638         u8 *iv = req->iv;
 639         int err;
 640
 641         if (cryptlen < authsize)
 642                 return -EINVAL;
 643         cryptlen -= authsize;
 644
 645         err = crypto_authenc_esn_iverify(req, iv, cryptlen);
 646         if (err)
 647                 return err;
 648
 649         ablkcipher_request_set_tfm(abreq, ctx->enc);
 650         ablkcipher_request_set_callback(abreq, aead_request_flags(req),
 651                                         req->base.complete, req->base.data);
 652         ablkcipher_request_set_crypt(abreq, req->src, req->dst, cryptlen, iv);
 653
 654         return crypto_ablkcipher_decrypt(abreq);
 655 }
 656
 657 static int crypto_authenc_esn_init_tfm(struct crypto_tfm *tfm)
 658 {
 659         struct crypto_instance *inst = crypto_tfm_alg_instance(tfm);
 660         struct authenc_esn_instance_ctx *ictx = crypto_instance_ctx(inst);
 661         struct crypto_authenc_esn_ctx *ctx = crypto_tfm_ctx(tfm);
 662         struct crypto_ahash *auth;
 663         struct crypto_ablkcipher *enc;
 664         int err;
 665
 666         auth = crypto_spawn_ahash(&ictx->auth);
 667         if (IS_ERR(auth))
 668                 return PTR_ERR(auth);
 669
 670         enc = crypto_spawn_skcipher(&ictx->enc);
 671         err = PTR_ERR(enc);
 672         if (IS_ERR(enc))
 673                 goto err_free_ahash;
 674
 675         ctx->auth = auth;
 676         ctx->enc = enc;
 677
 678         ctx->reqoff = ALIGN(2 * crypto_ahash_digestsize(auth) +
 679                             crypto_ahash_alignmask(auth),
 680                             crypto_ahash_alignmask(auth) + 1) +
 681                       crypto_ablkcipher_ivsize(enc);
 682
 683         tfm->crt_aead.reqsize = sizeof(struct authenc_esn_request_ctx) +
 684                                 ctx->reqoff +
 685                                 max_t(unsigned int,
 686                                 crypto_ahash_reqsize(auth) +
 687                                 sizeof(struct ahash_request),
 688                                 sizeof(struct skcipher_givcrypt_request) +
 689                                 crypto_ablkcipher_reqsize(enc));
 690
 691         return 0;
 692
 693 err_free_ahash:
 694         crypto_free_ahash(auth);
 695         return err;
 696 }
 697
 698 static void crypto_authenc_esn_exit_tfm(struct crypto_tfm *tfm)
 699 {
 700         struct crypto_authenc_esn_ctx *ctx = crypto_tfm_ctx(tfm);
 701
 702         crypto_free_ahash(ctx->auth);
 703         crypto_free_ablkcipher(ctx->enc);
 704 }
 705
 706 static struct crypto_instance *crypto_authenc_esn_alloc(struct rtattr **tb)
 707 {
 708         struct crypto_attr_type *algt;
 709         struct crypto_instance *inst;
 710         struct hash_alg_common *auth;
 711         struct crypto_alg *auth_base;
 712         struct crypto_alg *enc;
 713         struct authenc_esn_instance_ctx *ctx;
 714         const char *enc_name;
 715         int err;
 716
 717         algt = crypto_get_attr_type(tb);
 718         if (IS_ERR(algt))
 719                 return ERR_CAST(algt);
 720
 721         if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
 722                 return ERR_PTR(-EINVAL);
 723
 724         auth = ahash_attr_alg(tb[1], CRYPTO_ALG_TYPE_HASH,
 725                                CRYPTO_ALG_TYPE_AHASH_MASK);
 726         if (IS_ERR(auth))
 727                 return ERR_CAST(auth);
 728
 729         auth_base = &auth->base;
 730
 731         enc_name = crypto_attr_alg_name(tb[2]);
 732         err = PTR_ERR(enc_name);
 733         if (IS_ERR(enc_name))
 734                 goto out_put_auth;
 735
 736         inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
 737         err = -ENOMEM;
 738         if (!inst)
 739                 goto out_put_auth;
 740
 741         ctx = crypto_instance_ctx(inst);
 742
 743         err = crypto_init_ahash_spawn(&ctx->auth, auth, inst);
 744         if (err)
 745                 goto err_free_inst;
 746
 747         crypto_set_skcipher_spawn(&ctx->enc, inst);
 748         err = crypto_grab_skcipher(&ctx->enc, enc_name, 0,
 749                                    crypto_requires_sync(algt->type,
 750                                                         algt->mask));
 751         if (err)
 752                 goto err_drop_auth;
 753
 754         enc = crypto_skcipher_spawn_alg(&ctx->enc);
 755
 756         err = -ENAMETOOLONG;
 757         if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME,
 758                      "authencesn(%s,%s)", auth_base->cra_name, enc->cra_name) >=
 759             CRYPTO_MAX_ALG_NAME)
 760                 goto err_drop_enc;
 761
 762         if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
 763                      "authencesn(%s,%s)", auth_base->cra_driver_name,
 764                      enc->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
 765                 goto err_drop_enc;
 766
 767         inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD;
 768         inst->alg.cra_flags |= enc->cra_flags & CRYPTO_ALG_ASYNC;
 769         inst->alg.cra_priority = enc->cra_priority *
 770                                  10 + auth_base->cra_priority;
 771         inst->alg.cra_blocksize = enc->cra_blocksize;
 772         inst->alg.cra_alignmask = auth_base->cra_alignmask | enc->cra_alignmask;
 773         inst->alg.cra_type = &crypto_aead_type;
 774
 775         inst->alg.cra_aead.ivsize = enc->cra_ablkcipher.ivsize;
 776         inst->alg.cra_aead.maxauthsize = auth->digestsize;
 777
 778         inst->alg.cra_ctxsize = sizeof(struct crypto_authenc_esn_ctx);
 779
 780         inst->alg.cra_init = crypto_authenc_esn_init_tfm;
 781         inst->alg.cra_exit = crypto_authenc_esn_exit_tfm;
 782
 783         inst->alg.cra_aead.setkey = crypto_authenc_esn_setkey;
 784         inst->alg.cra_aead.encrypt = crypto_authenc_esn_encrypt;
 785         inst->alg.cra_aead.decrypt = crypto_authenc_esn_decrypt;
 786         inst->alg.cra_aead.givencrypt = crypto_authenc_esn_givencrypt;
 787
 788 out:
 789         crypto_mod_put(auth_base);
 790         return inst;
 791
 792 err_drop_enc:
 793         crypto_drop_skcipher(&ctx->enc);
 794 err_drop_auth:
 795         crypto_drop_ahash(&ctx->auth);
 796 err_free_inst:
 797         kfree(inst);
 798 out_put_auth:
 799         inst = ERR_PTR(err);
 800         goto out;
 801 }
 802
 803 static void crypto_authenc_esn_free(struct crypto_instance *inst)
 804 {
 805         struct authenc_esn_instance_ctx *ctx = crypto_instance_ctx(inst);
 806
 807         crypto_drop_skcipher(&ctx->enc);
 808         crypto_drop_ahash(&ctx->auth);
 809         kfree(inst);
 810 }
 811
 812 static struct crypto_template crypto_authenc_esn_tmpl = {
 813         .name = "authencesn",
 814         .alloc = crypto_authenc_esn_alloc,
 815         .free = crypto_authenc_esn_free,
 816         .module = THIS_MODULE,
 817 };
 818
 819 static int __init crypto_authenc_esn_module_init(void)
 820 {
 821         return crypto_register_template(&crypto_authenc_esn_tmpl);
 822 }
 823
 824 static void __exit crypto_authenc_esn_module_exit(void)
 825 {
 826         crypto_unregister_template(&crypto_authenc_esn_tmpl);
 827 }
 828
 829 module_init(crypto_authenc_esn_module_init);
 830 module_exit(crypto_authenc_esn_module_exit);
 831
 832 MODULE_LICENSE("GPL");
 833 MODULE_AUTHOR("Steffen Klassert <steffen.klassert@secunet.com>");
 834 MODULE_DESCRIPTION("AEAD wrapper for IPsec with extended sequence numbers");