linux/crypto/authenc.c
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   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
  26typedef u8 *(*authenc_ahash_t)(struct aead_request *req, unsigned int flags);
  27
  28struct authenc_instance_ctx {
  29        struct crypto_ahash_spawn auth;
  30        struct crypto_skcipher_spawn enc;
  31};
  32
  33struct crypto_authenc_ctx {
  34        unsigned int reqoff;
  35        struct crypto_ahash *auth;
  36        struct crypto_ablkcipher *enc;
  37};
  38
  39struct 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
  49static void authenc_request_complete(struct aead_request *req, int err)
  50{
  51        if (err != -EINPROGRESS)
  52                aead_request_complete(req, err);
  53}
  54
  55static 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
 102out:
 103        return err;
 104
 105badkey:
 106        crypto_aead_set_flags(authenc, CRYPTO_TFM_RES_BAD_KEY_LEN);
 107        goto out;
 108}
 109
 110static void authenc_geniv_ahash_update_done(struct crypto_async_request *areq,
 111                                            int err)
 112{
 113        struct aead_request *req = areq->data;
 114        struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 115        struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
 116        struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
 117        struct ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
 118
 119        if (err)
 120                goto out;
 121
 122        ahash_request_set_crypt(ahreq, areq_ctx->sg, ahreq->result,
 123                                areq_ctx->cryptlen);
 124        ahash_request_set_callback(ahreq, aead_request_flags(req) &
 125                                          CRYPTO_TFM_REQ_MAY_SLEEP,
 126                                   areq_ctx->complete, req);
 127
 128        err = crypto_ahash_finup(ahreq);
 129        if (err)
 130                goto out;
 131
 132        scatterwalk_map_and_copy(ahreq->result, areq_ctx->sg,
 133                                 areq_ctx->cryptlen,
 134                                 crypto_aead_authsize(authenc), 1);
 135
 136out:
 137        authenc_request_complete(req, err);
 138}
 139
 140static void authenc_geniv_ahash_done(struct crypto_async_request *areq, int err)
 141{
 142        struct aead_request *req = areq->data;
 143        struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 144        struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
 145        struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
 146        struct ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
 147
 148        if (err)
 149                goto out;
 150
 151        scatterwalk_map_and_copy(ahreq->result, areq_ctx->sg,
 152                                 areq_ctx->cryptlen,
 153                                 crypto_aead_authsize(authenc), 1);
 154
 155out:
 156        aead_request_complete(req, err);
 157}
 158
 159static void authenc_verify_ahash_update_done(struct crypto_async_request *areq,
 160                                             int err)
 161{
 162        u8 *ihash;
 163        unsigned int authsize;
 164        struct ablkcipher_request *abreq;
 165        struct aead_request *req = areq->data;
 166        struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 167        struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
 168        struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
 169        struct ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
 170        unsigned int cryptlen = req->cryptlen;
 171
 172        if (err)
 173                goto out;
 174
 175        ahash_request_set_crypt(ahreq, areq_ctx->sg, ahreq->result,
 176                                areq_ctx->cryptlen);
 177        ahash_request_set_callback(ahreq, aead_request_flags(req) &
 178                                          CRYPTO_TFM_REQ_MAY_SLEEP,
 179                                   areq_ctx->complete, req);
 180
 181        err = crypto_ahash_finup(ahreq);
 182        if (err)
 183                goto out;
 184
 185        authsize = crypto_aead_authsize(authenc);
 186        cryptlen -= authsize;
 187        ihash = ahreq->result + authsize;
 188        scatterwalk_map_and_copy(ihash, areq_ctx->sg, areq_ctx->cryptlen,
 189                                 authsize, 0);
 190
 191        err = memcmp(ihash, ahreq->result, authsize) ? -EBADMSG : 0;
 192        if (err)
 193                goto out;
 194
 195        abreq = aead_request_ctx(req);
 196        ablkcipher_request_set_tfm(abreq, ctx->enc);
 197        ablkcipher_request_set_callback(abreq, aead_request_flags(req),
 198                                        req->base.complete, req->base.data);
 199        ablkcipher_request_set_crypt(abreq, req->src, req->dst,
 200                                     cryptlen, req->iv);
 201
 202        err = crypto_ablkcipher_decrypt(abreq);
 203
 204out:
 205        authenc_request_complete(req, err);
 206}
 207
 208static void authenc_verify_ahash_done(struct crypto_async_request *areq,
 209                                      int err)
 210{
 211        u8 *ihash;
 212        unsigned int authsize;
 213        struct ablkcipher_request *abreq;
 214        struct aead_request *req = areq->data;
 215        struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 216        struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
 217        struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
 218        struct ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
 219        unsigned int cryptlen = req->cryptlen;
 220
 221        if (err)
 222                goto out;
 223
 224        authsize = crypto_aead_authsize(authenc);
 225        cryptlen -= authsize;
 226        ihash = ahreq->result + authsize;
 227        scatterwalk_map_and_copy(ihash, areq_ctx->sg, areq_ctx->cryptlen,
 228                                 authsize, 0);
 229
 230        err = memcmp(ihash, ahreq->result, authsize) ? -EBADMSG : 0;
 231        if (err)
 232                goto out;
 233
 234        abreq = aead_request_ctx(req);
 235        ablkcipher_request_set_tfm(abreq, ctx->enc);
 236        ablkcipher_request_set_callback(abreq, aead_request_flags(req),
 237                                        req->base.complete, req->base.data);
 238        ablkcipher_request_set_crypt(abreq, req->src, req->dst,
 239                                     cryptlen, req->iv);
 240
 241        err = crypto_ablkcipher_decrypt(abreq);
 242
 243out:
 244        authenc_request_complete(req, err);
 245}
 246
 247static u8 *crypto_authenc_ahash_fb(struct aead_request *req, unsigned int flags)
 248{
 249        struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 250        struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
 251        struct crypto_ahash *auth = ctx->auth;
 252        struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
 253        struct ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
 254        u8 *hash = areq_ctx->tail;
 255        int err;
 256
 257        hash = (u8 *)ALIGN((unsigned long)hash + crypto_ahash_alignmask(auth),
 258                            crypto_ahash_alignmask(auth) + 1);
 259
 260        ahash_request_set_tfm(ahreq, auth);
 261
 262        err = crypto_ahash_init(ahreq);
 263        if (err)
 264                return ERR_PTR(err);
 265
 266        ahash_request_set_crypt(ahreq, req->assoc, hash, req->assoclen);
 267        ahash_request_set_callback(ahreq, aead_request_flags(req) & flags,
 268                                   areq_ctx->update_complete, req);
 269
 270        err = crypto_ahash_update(ahreq);
 271        if (err)
 272                return ERR_PTR(err);
 273
 274        ahash_request_set_crypt(ahreq, areq_ctx->sg, hash,
 275                                areq_ctx->cryptlen);
 276        ahash_request_set_callback(ahreq, aead_request_flags(req) & flags,
 277                                   areq_ctx->complete, req);
 278
 279        err = crypto_ahash_finup(ahreq);
 280        if (err)
 281                return ERR_PTR(err);
 282
 283        return hash;
 284}
 285
 286static u8 *crypto_authenc_ahash(struct aead_request *req, unsigned int flags)
 287{
 288        struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 289        struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
 290        struct crypto_ahash *auth = ctx->auth;
 291        struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
 292        struct ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
 293        u8 *hash = areq_ctx->tail;
 294        int err;
 295
 296        hash = (u8 *)ALIGN((unsigned long)hash + crypto_ahash_alignmask(auth),
 297                           crypto_ahash_alignmask(auth) + 1);
 298
 299        ahash_request_set_tfm(ahreq, auth);
 300        ahash_request_set_crypt(ahreq, areq_ctx->sg, hash,
 301                                areq_ctx->cryptlen);
 302        ahash_request_set_callback(ahreq, aead_request_flags(req) & flags,
 303                                   areq_ctx->complete, req);
 304
 305        err = crypto_ahash_digest(ahreq);
 306        if (err)
 307                return ERR_PTR(err);
 308
 309        return hash;
 310}
 311
 312static int crypto_authenc_genicv(struct aead_request *req, u8 *iv,
 313                                 unsigned int flags)
 314{
 315        struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 316        struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
 317        struct scatterlist *dst = req->dst;
 318        struct scatterlist *assoc = req->assoc;
 319        struct scatterlist *cipher = areq_ctx->cipher;
 320        struct scatterlist *asg = areq_ctx->asg;
 321        unsigned int ivsize = crypto_aead_ivsize(authenc);
 322        unsigned int cryptlen = req->cryptlen;
 323        authenc_ahash_t authenc_ahash_fn = crypto_authenc_ahash_fb;
 324        struct page *dstp;
 325        u8 *vdst;
 326        u8 *hash;
 327
 328        dstp = sg_page(dst);
 329        vdst = PageHighMem(dstp) ? NULL : page_address(dstp) + dst->offset;
 330
 331        if (ivsize) {
 332                sg_init_table(cipher, 2);
 333                sg_set_buf(cipher, iv, ivsize);
 334                scatterwalk_crypto_chain(cipher, dst, vdst == iv + ivsize, 2);
 335                dst = cipher;
 336                cryptlen += ivsize;
 337        }
 338
 339        if (req->assoclen && sg_is_last(assoc)) {
 340                authenc_ahash_fn = crypto_authenc_ahash;
 341                sg_init_table(asg, 2);
 342                sg_set_page(asg, sg_page(assoc), assoc->length, assoc->offset);
 343                scatterwalk_crypto_chain(asg, dst, 0, 2);
 344                dst = asg;
 345                cryptlen += req->assoclen;
 346        }
 347
 348        areq_ctx->cryptlen = cryptlen;
 349        areq_ctx->sg = dst;
 350
 351        areq_ctx->complete = authenc_geniv_ahash_done;
 352        areq_ctx->update_complete = authenc_geniv_ahash_update_done;
 353
 354        hash = authenc_ahash_fn(req, flags);
 355        if (IS_ERR(hash))
 356                return PTR_ERR(hash);
 357
 358        scatterwalk_map_and_copy(hash, dst, cryptlen,
 359                                 crypto_aead_authsize(authenc), 1);
 360        return 0;
 361}
 362
 363static void crypto_authenc_encrypt_done(struct crypto_async_request *req,
 364                                        int err)
 365{
 366        struct aead_request *areq = req->data;
 367
 368        if (!err) {
 369                struct crypto_aead *authenc = crypto_aead_reqtfm(areq);
 370                struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
 371                struct ablkcipher_request *abreq = aead_request_ctx(areq);
 372                u8 *iv = (u8 *)(abreq + 1) +
 373                         crypto_ablkcipher_reqsize(ctx->enc);
 374
 375                err = crypto_authenc_genicv(areq, iv, 0);
 376        }
 377
 378        authenc_request_complete(areq, err);
 379}
 380
 381static int crypto_authenc_encrypt(struct aead_request *req)
 382{
 383        struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 384        struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
 385        struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
 386        struct crypto_ablkcipher *enc = ctx->enc;
 387        struct scatterlist *dst = req->dst;
 388        unsigned int cryptlen = req->cryptlen;
 389        struct ablkcipher_request *abreq = (void *)(areq_ctx->tail
 390                                                    + ctx->reqoff);
 391        u8 *iv = (u8 *)abreq - crypto_ablkcipher_ivsize(enc);
 392        int err;
 393
 394        ablkcipher_request_set_tfm(abreq, enc);
 395        ablkcipher_request_set_callback(abreq, aead_request_flags(req),
 396                                        crypto_authenc_encrypt_done, req);
 397        ablkcipher_request_set_crypt(abreq, req->src, dst, cryptlen, req->iv);
 398
 399        memcpy(iv, req->iv, crypto_aead_ivsize(authenc));
 400
 401        err = crypto_ablkcipher_encrypt(abreq);
 402        if (err)
 403                return err;
 404
 405        return crypto_authenc_genicv(req, iv, CRYPTO_TFM_REQ_MAY_SLEEP);
 406}
 407
 408static void crypto_authenc_givencrypt_done(struct crypto_async_request *req,
 409                                           int err)
 410{
 411        struct aead_request *areq = req->data;
 412
 413        if (!err) {
 414                struct skcipher_givcrypt_request *greq = aead_request_ctx(areq);
 415
 416                err = crypto_authenc_genicv(areq, greq->giv, 0);
 417        }
 418
 419        authenc_request_complete(areq, err);
 420}
 421
 422static int crypto_authenc_givencrypt(struct aead_givcrypt_request *req)
 423{
 424        struct crypto_aead *authenc = aead_givcrypt_reqtfm(req);
 425        struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
 426        struct aead_request *areq = &req->areq;
 427        struct skcipher_givcrypt_request *greq = aead_request_ctx(areq);
 428        u8 *iv = req->giv;
 429        int err;
 430
 431        skcipher_givcrypt_set_tfm(greq, ctx->enc);
 432        skcipher_givcrypt_set_callback(greq, aead_request_flags(areq),
 433                                       crypto_authenc_givencrypt_done, areq);
 434        skcipher_givcrypt_set_crypt(greq, areq->src, areq->dst, areq->cryptlen,
 435                                    areq->iv);
 436        skcipher_givcrypt_set_giv(greq, iv, req->seq);
 437
 438        err = crypto_skcipher_givencrypt(greq);
 439        if (err)
 440                return err;
 441
 442        return crypto_authenc_genicv(areq, iv, CRYPTO_TFM_REQ_MAY_SLEEP);
 443}
 444
 445static int crypto_authenc_verify(struct aead_request *req,
 446                                 authenc_ahash_t authenc_ahash_fn)
 447{
 448        struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 449        struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
 450        u8 *ohash;
 451        u8 *ihash;
 452        unsigned int authsize;
 453
 454        areq_ctx->complete = authenc_verify_ahash_done;
 455        areq_ctx->update_complete = authenc_verify_ahash_update_done;
 456
 457        ohash = authenc_ahash_fn(req, CRYPTO_TFM_REQ_MAY_SLEEP);
 458        if (IS_ERR(ohash))
 459                return PTR_ERR(ohash);
 460
 461        authsize = crypto_aead_authsize(authenc);
 462        ihash = ohash + authsize;
 463        scatterwalk_map_and_copy(ihash, areq_ctx->sg, areq_ctx->cryptlen,
 464                                 authsize, 0);
 465        return memcmp(ihash, ohash, authsize) ? -EBADMSG : 0;
 466}
 467
 468static int crypto_authenc_iverify(struct aead_request *req, u8 *iv,
 469                                  unsigned int cryptlen)
 470{
 471        struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 472        struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
 473        struct scatterlist *src = req->src;
 474        struct scatterlist *assoc = req->assoc;
 475        struct scatterlist *cipher = areq_ctx->cipher;
 476        struct scatterlist *asg = areq_ctx->asg;
 477        unsigned int ivsize = crypto_aead_ivsize(authenc);
 478        authenc_ahash_t authenc_ahash_fn = crypto_authenc_ahash_fb;
 479        struct page *srcp;
 480        u8 *vsrc;
 481
 482        srcp = sg_page(src);
 483        vsrc = PageHighMem(srcp) ? NULL : page_address(srcp) + src->offset;
 484
 485        if (ivsize) {
 486                sg_init_table(cipher, 2);
 487                sg_set_buf(cipher, iv, ivsize);
 488                scatterwalk_crypto_chain(cipher, src, vsrc == iv + ivsize, 2);
 489                src = cipher;
 490                cryptlen += ivsize;
 491        }
 492
 493        if (req->assoclen && sg_is_last(assoc)) {
 494                authenc_ahash_fn = crypto_authenc_ahash;
 495                sg_init_table(asg, 2);
 496                sg_set_page(asg, sg_page(assoc), assoc->length, assoc->offset);
 497                scatterwalk_crypto_chain(asg, src, 0, 2);
 498                src = asg;
 499                cryptlen += req->assoclen;
 500        }
 501
 502        areq_ctx->cryptlen = cryptlen;
 503        areq_ctx->sg = src;
 504
 505        return crypto_authenc_verify(req, authenc_ahash_fn);
 506}
 507
 508static int crypto_authenc_decrypt(struct aead_request *req)
 509{
 510        struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 511        struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
 512        struct ablkcipher_request *abreq = aead_request_ctx(req);
 513        unsigned int cryptlen = req->cryptlen;
 514        unsigned int authsize = crypto_aead_authsize(authenc);
 515        u8 *iv = req->iv;
 516        int err;
 517
 518        if (cryptlen < authsize)
 519                return -EINVAL;
 520        cryptlen -= authsize;
 521
 522        err = crypto_authenc_iverify(req, iv, cryptlen);
 523        if (err)
 524                return err;
 525
 526        ablkcipher_request_set_tfm(abreq, ctx->enc);
 527        ablkcipher_request_set_callback(abreq, aead_request_flags(req),
 528                                        req->base.complete, req->base.data);
 529        ablkcipher_request_set_crypt(abreq, req->src, req->dst, cryptlen, iv);
 530
 531        return crypto_ablkcipher_decrypt(abreq);
 532}
 533
 534static int crypto_authenc_init_tfm(struct crypto_tfm *tfm)
 535{
 536        struct crypto_instance *inst = crypto_tfm_alg_instance(tfm);
 537        struct authenc_instance_ctx *ictx = crypto_instance_ctx(inst);
 538        struct crypto_authenc_ctx *ctx = crypto_tfm_ctx(tfm);
 539        struct crypto_ahash *auth;
 540        struct crypto_ablkcipher *enc;
 541        int err;
 542
 543        auth = crypto_spawn_ahash(&ictx->auth);
 544        if (IS_ERR(auth))
 545                return PTR_ERR(auth);
 546
 547        enc = crypto_spawn_skcipher(&ictx->enc);
 548        err = PTR_ERR(enc);
 549        if (IS_ERR(enc))
 550                goto err_free_ahash;
 551
 552        ctx->auth = auth;
 553        ctx->enc = enc;
 554
 555        ctx->reqoff = ALIGN(2 * crypto_ahash_digestsize(auth) +
 556                            crypto_ahash_alignmask(auth),
 557                            crypto_ahash_alignmask(auth) + 1) +
 558                      crypto_ablkcipher_ivsize(enc);
 559
 560        tfm->crt_aead.reqsize = sizeof(struct authenc_request_ctx) +
 561                                ctx->reqoff +
 562                                max_t(unsigned int,
 563                                crypto_ahash_reqsize(auth) +
 564                                sizeof(struct ahash_request),
 565                                sizeof(struct skcipher_givcrypt_request) +
 566                                crypto_ablkcipher_reqsize(enc));
 567
 568        return 0;
 569
 570err_free_ahash:
 571        crypto_free_ahash(auth);
 572        return err;
 573}
 574
 575static void crypto_authenc_exit_tfm(struct crypto_tfm *tfm)
 576{
 577        struct crypto_authenc_ctx *ctx = crypto_tfm_ctx(tfm);
 578
 579        crypto_free_ahash(ctx->auth);
 580        crypto_free_ablkcipher(ctx->enc);
 581}
 582
 583static struct crypto_instance *crypto_authenc_alloc(struct rtattr **tb)
 584{
 585        struct crypto_attr_type *algt;
 586        struct crypto_instance *inst;
 587        struct hash_alg_common *auth;
 588        struct crypto_alg *auth_base;
 589        struct crypto_alg *enc;
 590        struct authenc_instance_ctx *ctx;
 591        const char *enc_name;
 592        int err;
 593
 594        algt = crypto_get_attr_type(tb);
 595        if (IS_ERR(algt))
 596                return ERR_CAST(algt);
 597
 598        if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
 599                return ERR_PTR(-EINVAL);
 600
 601        auth = ahash_attr_alg(tb[1], CRYPTO_ALG_TYPE_HASH,
 602                               CRYPTO_ALG_TYPE_AHASH_MASK);
 603        if (IS_ERR(auth))
 604                return ERR_CAST(auth);
 605
 606        auth_base = &auth->base;
 607
 608        enc_name = crypto_attr_alg_name(tb[2]);
 609        err = PTR_ERR(enc_name);
 610        if (IS_ERR(enc_name))
 611                goto out_put_auth;
 612
 613        inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
 614        err = -ENOMEM;
 615        if (!inst)
 616                goto out_put_auth;
 617
 618        ctx = crypto_instance_ctx(inst);
 619
 620        err = crypto_init_ahash_spawn(&ctx->auth, auth, inst);
 621        if (err)
 622                goto err_free_inst;
 623
 624        crypto_set_skcipher_spawn(&ctx->enc, inst);
 625        err = crypto_grab_skcipher(&ctx->enc, enc_name, 0,
 626                                   crypto_requires_sync(algt->type,
 627                                                        algt->mask));
 628        if (err)
 629                goto err_drop_auth;
 630
 631        enc = crypto_skcipher_spawn_alg(&ctx->enc);
 632
 633        err = -ENAMETOOLONG;
 634        if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME,
 635                     "authenc(%s,%s)", auth_base->cra_name, enc->cra_name) >=
 636            CRYPTO_MAX_ALG_NAME)
 637                goto err_drop_enc;
 638
 639        if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
 640                     "authenc(%s,%s)", auth_base->cra_driver_name,
 641                     enc->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
 642                goto err_drop_enc;
 643
 644        inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD;
 645        inst->alg.cra_flags |= enc->cra_flags & CRYPTO_ALG_ASYNC;
 646        inst->alg.cra_priority = enc->cra_priority *
 647                                 10 + auth_base->cra_priority;
 648        inst->alg.cra_blocksize = enc->cra_blocksize;
 649        inst->alg.cra_alignmask = auth_base->cra_alignmask | enc->cra_alignmask;
 650        inst->alg.cra_type = &crypto_aead_type;
 651
 652        inst->alg.cra_aead.ivsize = enc->cra_ablkcipher.ivsize;
 653        inst->alg.cra_aead.maxauthsize = auth->digestsize;
 654
 655        inst->alg.cra_ctxsize = sizeof(struct crypto_authenc_ctx);
 656
 657        inst->alg.cra_init = crypto_authenc_init_tfm;
 658        inst->alg.cra_exit = crypto_authenc_exit_tfm;
 659
 660        inst->alg.cra_aead.setkey = crypto_authenc_setkey;
 661        inst->alg.cra_aead.encrypt = crypto_authenc_encrypt;
 662        inst->alg.cra_aead.decrypt = crypto_authenc_decrypt;
 663        inst->alg.cra_aead.givencrypt = crypto_authenc_givencrypt;
 664
 665out:
 666        crypto_mod_put(auth_base);
 667        return inst;
 668
 669err_drop_enc:
 670        crypto_drop_skcipher(&ctx->enc);
 671err_drop_auth:
 672        crypto_drop_ahash(&ctx->auth);
 673err_free_inst:
 674        kfree(inst);
 675out_put_auth:
 676        inst = ERR_PTR(err);
 677        goto out;
 678}
 679
 680static void crypto_authenc_free(struct crypto_instance *inst)
 681{
 682        struct authenc_instance_ctx *ctx = crypto_instance_ctx(inst);
 683
 684        crypto_drop_skcipher(&ctx->enc);
 685        crypto_drop_ahash(&ctx->auth);
 686        kfree(inst);
 687}
 688
 689static struct crypto_template crypto_authenc_tmpl = {
 690        .name = "authenc",
 691        .alloc = crypto_authenc_alloc,
 692        .free = crypto_authenc_free,
 693        .module = THIS_MODULE,
 694};
 695
 696static int __init crypto_authenc_module_init(void)
 697{
 698        return crypto_register_template(&crypto_authenc_tmpl);
 699}
 700
 701static void __exit crypto_authenc_module_exit(void)
 702{
 703        crypto_unregister_template(&crypto_authenc_tmpl);
 704}
 705
 706module_init(crypto_authenc_module_init);
 707module_exit(crypto_authenc_module_exit);
 708
 709MODULE_LICENSE("GPL");
 710MODULE_DESCRIPTION("Simple AEAD wrapper for IPsec");
 711
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