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_chain(struct scatterlist *head, struct scatterlist *sg,
 111                          int chain)
 112{
 113        if (chain) {
 114                head->length += sg->length;
 115                sg = scatterwalk_sg_next(sg);
 116        }
 117
 118        if (sg)
 119                scatterwalk_sg_chain(head, 2, sg);
 120        else
 121                sg_mark_end(head);
 122}
 123
 124static void authenc_geniv_ahash_update_done(struct crypto_async_request *areq,
 125                                            int err)
 126{
 127        struct aead_request *req = areq->data;
 128        struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 129        struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
 130        struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
 131        struct ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
 132
 133        if (err)
 134                goto out;
 135
 136        ahash_request_set_crypt(ahreq, areq_ctx->sg, ahreq->result,
 137                                areq_ctx->cryptlen);
 138        ahash_request_set_callback(ahreq, aead_request_flags(req) &
 139                                          CRYPTO_TFM_REQ_MAY_SLEEP,
 140                                   areq_ctx->complete, req);
 141
 142        err = crypto_ahash_finup(ahreq);
 143        if (err)
 144                goto out;
 145
 146        scatterwalk_map_and_copy(ahreq->result, areq_ctx->sg,
 147                                 areq_ctx->cryptlen,
 148                                 crypto_aead_authsize(authenc), 1);
 149
 150out:
 151        authenc_request_complete(req, err);
 152}
 153
 154static void authenc_geniv_ahash_done(struct crypto_async_request *areq, int err)
 155{
 156        struct aead_request *req = areq->data;
 157        struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 158        struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
 159        struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
 160        struct ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
 161
 162        if (err)
 163                goto out;
 164
 165        scatterwalk_map_and_copy(ahreq->result, areq_ctx->sg,
 166                                 areq_ctx->cryptlen,
 167                                 crypto_aead_authsize(authenc), 1);
 168
 169out:
 170        aead_request_complete(req, err);
 171}
 172
 173static void authenc_verify_ahash_update_done(struct crypto_async_request *areq,
 174                                             int err)
 175{
 176        u8 *ihash;
 177        unsigned int authsize;
 178        struct ablkcipher_request *abreq;
 179        struct aead_request *req = areq->data;
 180        struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 181        struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
 182        struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
 183        struct ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
 184        unsigned int cryptlen = req->cryptlen;
 185
 186        if (err)
 187                goto out;
 188
 189        ahash_request_set_crypt(ahreq, areq_ctx->sg, ahreq->result,
 190                                areq_ctx->cryptlen);
 191        ahash_request_set_callback(ahreq, aead_request_flags(req) &
 192                                          CRYPTO_TFM_REQ_MAY_SLEEP,
 193                                   areq_ctx->complete, req);
 194
 195        err = crypto_ahash_finup(ahreq);
 196        if (err)
 197                goto out;
 198
 199        authsize = crypto_aead_authsize(authenc);
 200        cryptlen -= authsize;
 201        ihash = ahreq->result + authsize;
 202        scatterwalk_map_and_copy(ihash, areq_ctx->sg, areq_ctx->cryptlen,
 203                                 authsize, 0);
 204
 205        err = memcmp(ihash, ahreq->result, authsize) ? -EBADMSG : 0;
 206        if (err)
 207                goto out;
 208
 209        abreq = aead_request_ctx(req);
 210        ablkcipher_request_set_tfm(abreq, ctx->enc);
 211        ablkcipher_request_set_callback(abreq, aead_request_flags(req),
 212                                        req->base.complete, req->base.data);
 213        ablkcipher_request_set_crypt(abreq, req->src, req->dst,
 214                                     cryptlen, req->iv);
 215
 216        err = crypto_ablkcipher_decrypt(abreq);
 217
 218out:
 219        authenc_request_complete(req, err);
 220}
 221
 222static void authenc_verify_ahash_done(struct crypto_async_request *areq,
 223                                      int err)
 224{
 225        u8 *ihash;
 226        unsigned int authsize;
 227        struct ablkcipher_request *abreq;
 228        struct aead_request *req = areq->data;
 229        struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 230        struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
 231        struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
 232        struct ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
 233        unsigned int cryptlen = req->cryptlen;
 234
 235        if (err)
 236                goto out;
 237
 238        authsize = crypto_aead_authsize(authenc);
 239        cryptlen -= authsize;
 240        ihash = ahreq->result + authsize;
 241        scatterwalk_map_and_copy(ihash, areq_ctx->sg, areq_ctx->cryptlen,
 242                                 authsize, 0);
 243
 244        err = memcmp(ihash, ahreq->result, authsize) ? -EBADMSG : 0;
 245        if (err)
 246                goto out;
 247
 248        abreq = aead_request_ctx(req);
 249        ablkcipher_request_set_tfm(abreq, ctx->enc);
 250        ablkcipher_request_set_callback(abreq, aead_request_flags(req),
 251                                        req->base.complete, req->base.data);
 252        ablkcipher_request_set_crypt(abreq, req->src, req->dst,
 253                                     cryptlen, req->iv);
 254
 255        err = crypto_ablkcipher_decrypt(abreq);
 256
 257out:
 258        authenc_request_complete(req, err);
 259}
 260
 261static u8 *crypto_authenc_ahash_fb(struct aead_request *req, unsigned int flags)
 262{
 263        struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 264        struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
 265        struct crypto_ahash *auth = ctx->auth;
 266        struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
 267        struct ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
 268        u8 *hash = areq_ctx->tail;
 269        int err;
 270
 271        hash = (u8 *)ALIGN((unsigned long)hash + crypto_ahash_alignmask(auth),
 272                            crypto_ahash_alignmask(auth) + 1);
 273
 274        ahash_request_set_tfm(ahreq, auth);
 275
 276        err = crypto_ahash_init(ahreq);
 277        if (err)
 278                return ERR_PTR(err);
 279
 280        ahash_request_set_crypt(ahreq, req->assoc, hash, req->assoclen);
 281        ahash_request_set_callback(ahreq, aead_request_flags(req) & flags,
 282                                   areq_ctx->update_complete, req);
 283
 284        err = crypto_ahash_update(ahreq);
 285        if (err)
 286                return ERR_PTR(err);
 287
 288        ahash_request_set_crypt(ahreq, areq_ctx->sg, hash,
 289                                areq_ctx->cryptlen);
 290        ahash_request_set_callback(ahreq, aead_request_flags(req) & flags,
 291                                   areq_ctx->complete, req);
 292
 293        err = crypto_ahash_finup(ahreq);
 294        if (err)
 295                return ERR_PTR(err);
 296
 297        return hash;
 298}
 299
 300static u8 *crypto_authenc_ahash(struct aead_request *req, unsigned int flags)
 301{
 302        struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 303        struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
 304        struct crypto_ahash *auth = ctx->auth;
 305        struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
 306        struct ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
 307        u8 *hash = areq_ctx->tail;
 308        int err;
 309
 310        hash = (u8 *)ALIGN((unsigned long)hash + crypto_ahash_alignmask(auth),
 311                           crypto_ahash_alignmask(auth) + 1);
 312
 313        ahash_request_set_tfm(ahreq, auth);
 314        ahash_request_set_crypt(ahreq, areq_ctx->sg, hash,
 315                                areq_ctx->cryptlen);
 316        ahash_request_set_callback(ahreq, aead_request_flags(req) & flags,
 317                                   areq_ctx->complete, req);
 318
 319        err = crypto_ahash_digest(ahreq);
 320        if (err)
 321                return ERR_PTR(err);
 322
 323        return hash;
 324}
 325
 326static int crypto_authenc_genicv(struct aead_request *req, u8 *iv,
 327                                 unsigned int flags)
 328{
 329        struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 330        struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
 331        struct scatterlist *dst = req->dst;
 332        struct scatterlist *assoc = req->assoc;
 333        struct scatterlist *cipher = areq_ctx->cipher;
 334        struct scatterlist *asg = areq_ctx->asg;
 335        unsigned int ivsize = crypto_aead_ivsize(authenc);
 336        unsigned int cryptlen = req->cryptlen;
 337        authenc_ahash_t authenc_ahash_fn = crypto_authenc_ahash_fb;
 338        struct page *dstp;
 339        u8 *vdst;
 340        u8 *hash;
 341
 342        dstp = sg_page(dst);
 343        vdst = PageHighMem(dstp) ? NULL : page_address(dstp) + dst->offset;
 344
 345        if (ivsize) {
 346                sg_init_table(cipher, 2);
 347                sg_set_buf(cipher, iv, ivsize);
 348                authenc_chain(cipher, dst, vdst == iv + ivsize);
 349                dst = cipher;
 350                cryptlen += ivsize;
 351        }
 352
 353        if (sg_is_last(assoc)) {
 354                authenc_ahash_fn = crypto_authenc_ahash;
 355                sg_init_table(asg, 2);
 356                sg_set_page(asg, sg_page(assoc), assoc->length, assoc->offset);
 357                authenc_chain(asg, dst, 0);
 358                dst = asg;
 359                cryptlen += req->assoclen;
 360        }
 361
 362        areq_ctx->cryptlen = cryptlen;
 363        areq_ctx->sg = dst;
 364
 365        areq_ctx->complete = authenc_geniv_ahash_done;
 366        areq_ctx->update_complete = authenc_geniv_ahash_update_done;
 367
 368        hash = authenc_ahash_fn(req, flags);
 369        if (IS_ERR(hash))
 370                return PTR_ERR(hash);
 371
 372        scatterwalk_map_and_copy(hash, dst, cryptlen,
 373                                 crypto_aead_authsize(authenc), 1);
 374        return 0;
 375}
 376
 377static void crypto_authenc_encrypt_done(struct crypto_async_request *req,
 378                                        int err)
 379{
 380        struct aead_request *areq = req->data;
 381
 382        if (!err) {
 383                struct crypto_aead *authenc = crypto_aead_reqtfm(areq);
 384                struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
 385                struct ablkcipher_request *abreq = aead_request_ctx(areq);
 386                u8 *iv = (u8 *)(abreq + 1) +
 387                         crypto_ablkcipher_reqsize(ctx->enc);
 388
 389                err = crypto_authenc_genicv(areq, iv, 0);
 390        }
 391
 392        authenc_request_complete(areq, err);
 393}
 394
 395static int crypto_authenc_encrypt(struct aead_request *req)
 396{
 397        struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 398        struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
 399        struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
 400        struct crypto_ablkcipher *enc = ctx->enc;
 401        struct scatterlist *dst = req->dst;
 402        unsigned int cryptlen = req->cryptlen;
 403        struct ablkcipher_request *abreq = (void *)(areq_ctx->tail
 404                                                    + ctx->reqoff);
 405        u8 *iv = (u8 *)abreq - crypto_ablkcipher_ivsize(enc);
 406        int err;
 407
 408        ablkcipher_request_set_tfm(abreq, enc);
 409        ablkcipher_request_set_callback(abreq, aead_request_flags(req),
 410                                        crypto_authenc_encrypt_done, req);
 411        ablkcipher_request_set_crypt(abreq, req->src, dst, cryptlen, req->iv);
 412
 413        memcpy(iv, req->iv, crypto_aead_ivsize(authenc));
 414
 415        err = crypto_ablkcipher_encrypt(abreq);
 416        if (err)
 417                return err;
 418
 419        return crypto_authenc_genicv(req, iv, CRYPTO_TFM_REQ_MAY_SLEEP);
 420}
 421
 422static void crypto_authenc_givencrypt_done(struct crypto_async_request *req,
 423                                           int err)
 424{
 425        struct aead_request *areq = req->data;
 426
 427        if (!err) {
 428                struct skcipher_givcrypt_request *greq = aead_request_ctx(areq);
 429
 430                err = crypto_authenc_genicv(areq, greq->giv, 0);
 431        }
 432
 433        authenc_request_complete(areq, err);
 434}
 435
 436static int crypto_authenc_givencrypt(struct aead_givcrypt_request *req)
 437{
 438        struct crypto_aead *authenc = aead_givcrypt_reqtfm(req);
 439        struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
 440        struct aead_request *areq = &req->areq;
 441        struct skcipher_givcrypt_request *greq = aead_request_ctx(areq);
 442        u8 *iv = req->giv;
 443        int err;
 444
 445        skcipher_givcrypt_set_tfm(greq, ctx->enc);
 446        skcipher_givcrypt_set_callback(greq, aead_request_flags(areq),
 447                                       crypto_authenc_givencrypt_done, areq);
 448        skcipher_givcrypt_set_crypt(greq, areq->src, areq->dst, areq->cryptlen,
 449                                    areq->iv);
 450        skcipher_givcrypt_set_giv(greq, iv, req->seq);
 451
 452        err = crypto_skcipher_givencrypt(greq);
 453        if (err)
 454                return err;
 455
 456        return crypto_authenc_genicv(areq, iv, CRYPTO_TFM_REQ_MAY_SLEEP);
 457}
 458
 459static int crypto_authenc_verify(struct aead_request *req,
 460                                 authenc_ahash_t authenc_ahash_fn)
 461{
 462        struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 463        struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
 464        u8 *ohash;
 465        u8 *ihash;
 466        unsigned int authsize;
 467
 468        areq_ctx->complete = authenc_verify_ahash_done;
 469        areq_ctx->update_complete = authenc_verify_ahash_update_done;
 470
 471        ohash = authenc_ahash_fn(req, CRYPTO_TFM_REQ_MAY_SLEEP);
 472        if (IS_ERR(ohash))
 473                return PTR_ERR(ohash);
 474
 475        authsize = crypto_aead_authsize(authenc);
 476        ihash = ohash + authsize;
 477        scatterwalk_map_and_copy(ihash, areq_ctx->sg, areq_ctx->cryptlen,
 478                                 authsize, 0);
 479        return memcmp(ihash, ohash, authsize) ? -EBADMSG : 0;
 480}
 481
 482static int crypto_authenc_iverify(struct aead_request *req, u8 *iv,
 483                                  unsigned int cryptlen)
 484{
 485        struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 486        struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
 487        struct scatterlist *src = req->src;
 488        struct scatterlist *assoc = req->assoc;
 489        struct scatterlist *cipher = areq_ctx->cipher;
 490        struct scatterlist *asg = areq_ctx->asg;
 491        unsigned int ivsize = crypto_aead_ivsize(authenc);
 492        authenc_ahash_t authenc_ahash_fn = crypto_authenc_ahash_fb;
 493        struct page *srcp;
 494        u8 *vsrc;
 495
 496        srcp = sg_page(src);
 497        vsrc = PageHighMem(srcp) ? NULL : page_address(srcp) + src->offset;
 498
 499        if (ivsize) {
 500                sg_init_table(cipher, 2);
 501                sg_set_buf(cipher, iv, ivsize);
 502                authenc_chain(cipher, src, vsrc == iv + ivsize);
 503                src = cipher;
 504                cryptlen += ivsize;
 505        }
 506
 507        if (sg_is_last(assoc)) {
 508                authenc_ahash_fn = crypto_authenc_ahash;
 509                sg_init_table(asg, 2);
 510                sg_set_page(asg, sg_page(assoc), assoc->length, assoc->offset);
 511                authenc_chain(asg, src, 0);
 512                src = asg;
 513                cryptlen += req->assoclen;
 514        }
 515
 516        areq_ctx->cryptlen = cryptlen;
 517        areq_ctx->sg = src;
 518
 519        return crypto_authenc_verify(req, authenc_ahash_fn);
 520}
 521
 522static int crypto_authenc_decrypt(struct aead_request *req)
 523{
 524        struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 525        struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
 526        struct ablkcipher_request *abreq = aead_request_ctx(req);
 527        unsigned int cryptlen = req->cryptlen;
 528        unsigned int authsize = crypto_aead_authsize(authenc);
 529        u8 *iv = req->iv;
 530        int err;
 531
 532        if (cryptlen < authsize)
 533                return -EINVAL;
 534        cryptlen -= authsize;
 535
 536        err = crypto_authenc_iverify(req, iv, cryptlen);
 537        if (err)
 538                return err;
 539
 540        ablkcipher_request_set_tfm(abreq, ctx->enc);
 541        ablkcipher_request_set_callback(abreq, aead_request_flags(req),
 542                                        req->base.complete, req->base.data);
 543        ablkcipher_request_set_crypt(abreq, req->src, req->dst, cryptlen, iv);
 544
 545        return crypto_ablkcipher_decrypt(abreq);
 546}
 547
 548static int crypto_authenc_init_tfm(struct crypto_tfm *tfm)
 549{
 550        struct crypto_instance *inst = crypto_tfm_alg_instance(tfm);
 551        struct authenc_instance_ctx *ictx = crypto_instance_ctx(inst);
 552        struct crypto_authenc_ctx *ctx = crypto_tfm_ctx(tfm);
 553        struct crypto_ahash *auth;
 554        struct crypto_ablkcipher *enc;
 555        int err;
 556
 557        auth = crypto_spawn_ahash(&ictx->auth);
 558        if (IS_ERR(auth))
 559                return PTR_ERR(auth);
 560
 561        enc = crypto_spawn_skcipher(&ictx->enc);
 562        err = PTR_ERR(enc);
 563        if (IS_ERR(enc))
 564                goto err_free_ahash;
 565
 566        ctx->auth = auth;
 567        ctx->enc = enc;
 568
 569        ctx->reqoff = ALIGN(2 * crypto_ahash_digestsize(auth) +
 570                            crypto_ahash_alignmask(auth),
 571                            crypto_ahash_alignmask(auth) + 1) +
 572                      crypto_ablkcipher_ivsize(enc);
 573
 574        tfm->crt_aead.reqsize = sizeof(struct authenc_request_ctx) +
 575                                ctx->reqoff +
 576                                max_t(unsigned int,
 577                                crypto_ahash_reqsize(auth) +
 578                                sizeof(struct ahash_request),
 579                                sizeof(struct skcipher_givcrypt_request) +
 580                                crypto_ablkcipher_reqsize(enc));
 581
 582        return 0;
 583
 584err_free_ahash:
 585        crypto_free_ahash(auth);
 586        return err;
 587}
 588
 589static void crypto_authenc_exit_tfm(struct crypto_tfm *tfm)
 590{
 591        struct crypto_authenc_ctx *ctx = crypto_tfm_ctx(tfm);
 592
 593        crypto_free_ahash(ctx->auth);
 594        crypto_free_ablkcipher(ctx->enc);
 595}
 596
 597static struct crypto_instance *crypto_authenc_alloc(struct rtattr **tb)
 598{
 599        struct crypto_attr_type *algt;
 600        struct crypto_instance *inst;
 601        struct hash_alg_common *auth;
 602        struct crypto_alg *auth_base;
 603        struct crypto_alg *enc;
 604        struct authenc_instance_ctx *ctx;
 605        const char *enc_name;
 606        int err;
 607
 608        algt = crypto_get_attr_type(tb);
 609        err = PTR_ERR(algt);
 610        if (IS_ERR(algt))
 611                return ERR_PTR(err);
 612
 613        if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
 614                return ERR_PTR(-EINVAL);
 615
 616        auth = ahash_attr_alg(tb[1], CRYPTO_ALG_TYPE_HASH,
 617                               CRYPTO_ALG_TYPE_AHASH_MASK);
 618        if (IS_ERR(auth))
 619                return ERR_CAST(auth);
 620
 621        auth_base = &auth->base;
 622
 623        enc_name = crypto_attr_alg_name(tb[2]);
 624        err = PTR_ERR(enc_name);
 625        if (IS_ERR(enc_name))
 626                goto out_put_auth;
 627
 628        inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
 629        err = -ENOMEM;
 630        if (!inst)
 631                goto out_put_auth;
 632
 633        ctx = crypto_instance_ctx(inst);
 634
 635        err = crypto_init_ahash_spawn(&ctx->auth, auth, inst);
 636        if (err)
 637                goto err_free_inst;
 638
 639        crypto_set_skcipher_spawn(&ctx->enc, inst);
 640        err = crypto_grab_skcipher(&ctx->enc, enc_name, 0,
 641                                   crypto_requires_sync(algt->type,
 642                                                        algt->mask));
 643        if (err)
 644                goto err_drop_auth;
 645
 646        enc = crypto_skcipher_spawn_alg(&ctx->enc);
 647
 648        err = -ENAMETOOLONG;
 649        if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME,
 650                     "authenc(%s,%s)", auth_base->cra_name, enc->cra_name) >=
 651            CRYPTO_MAX_ALG_NAME)
 652                goto err_drop_enc;
 653
 654        if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
 655                     "authenc(%s,%s)", auth_base->cra_driver_name,
 656                     enc->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
 657                goto err_drop_enc;
 658
 659        inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD;
 660        inst->alg.cra_flags |= enc->cra_flags & CRYPTO_ALG_ASYNC;
 661        inst->alg.cra_priority = enc->cra_priority *
 662                                 10 + auth_base->cra_priority;
 663        inst->alg.cra_blocksize = enc->cra_blocksize;
 664        inst->alg.cra_alignmask = auth_base->cra_alignmask | enc->cra_alignmask;
 665        inst->alg.cra_type = &crypto_aead_type;
 666
 667        inst->alg.cra_aead.ivsize = enc->cra_ablkcipher.ivsize;
 668        inst->alg.cra_aead.maxauthsize = auth->digestsize;
 669
 670        inst->alg.cra_ctxsize = sizeof(struct crypto_authenc_ctx);
 671
 672        inst->alg.cra_init = crypto_authenc_init_tfm;
 673        inst->alg.cra_exit = crypto_authenc_exit_tfm;
 674
 675        inst->alg.cra_aead.setkey = crypto_authenc_setkey;
 676        inst->alg.cra_aead.encrypt = crypto_authenc_encrypt;
 677        inst->alg.cra_aead.decrypt = crypto_authenc_decrypt;
 678        inst->alg.cra_aead.givencrypt = crypto_authenc_givencrypt;
 679
 680out:
 681        crypto_mod_put(auth_base);
 682        return inst;
 683
 684err_drop_enc:
 685        crypto_drop_skcipher(&ctx->enc);
 686err_drop_auth:
 687        crypto_drop_ahash(&ctx->auth);
 688err_free_inst:
 689        kfree(inst);
 690out_put_auth:
 691        inst = ERR_PTR(err);
 692        goto out;
 693}
 694
 695static void crypto_authenc_free(struct crypto_instance *inst)
 696{
 697        struct authenc_instance_ctx *ctx = crypto_instance_ctx(inst);
 698
 699        crypto_drop_skcipher(&ctx->enc);
 700        crypto_drop_ahash(&ctx->auth);
 701        kfree(inst);
 702}
 703
 704static struct crypto_template crypto_authenc_tmpl = {
 705        .name = "authenc",
 706        .alloc = crypto_authenc_alloc,
 707        .free = crypto_authenc_free,
 708        .module = THIS_MODULE,
 709};
 710
 711static int __init crypto_authenc_module_init(void)
 712{
 713        return crypto_register_template(&crypto_authenc_tmpl);
 714}
 715
 716static void __exit crypto_authenc_module_exit(void)
 717{
 718        crypto_unregister_template(&crypto_authenc_tmpl);
 719}
 720
 721module_init(crypto_authenc_module_init);
 722module_exit(crypto_authenc_module_exit);
 723
 724MODULE_LICENSE("GPL");
 725MODULE_DESCRIPTION("Simple AEAD wrapper for IPsec");
 726