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
  55int crypto_authenc_extractkeys(struct crypto_authenc_keys *keys, const u8 *key,
  56                               unsigned int keylen)
  57{
  58        struct rtattr *rta = (struct rtattr *)key;
  59        struct crypto_authenc_key_param *param;
  60
  61        if (!RTA_OK(rta, keylen))
  62                return -EINVAL;
  63        if (rta->rta_type != CRYPTO_AUTHENC_KEYA_PARAM)
  64                return -EINVAL;
  65        if (RTA_PAYLOAD(rta) < sizeof(*param))
  66                return -EINVAL;
  67
  68        param = RTA_DATA(rta);
  69        keys->enckeylen = be32_to_cpu(param->enckeylen);
  70
  71        key += RTA_ALIGN(rta->rta_len);
  72        keylen -= RTA_ALIGN(rta->rta_len);
  73
  74        if (keylen < keys->enckeylen)
  75                return -EINVAL;
  76
  77        keys->authkeylen = keylen - keys->enckeylen;
  78        keys->authkey = key;
  79        keys->enckey = key + keys->authkeylen;
  80
  81        return 0;
  82}
  83EXPORT_SYMBOL_GPL(crypto_authenc_extractkeys);
  84
  85static int crypto_authenc_setkey(struct crypto_aead *authenc, const u8 *key,
  86                                 unsigned int keylen)
  87{
  88        struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
  89        struct crypto_ahash *auth = ctx->auth;
  90        struct crypto_ablkcipher *enc = ctx->enc;
  91        struct crypto_authenc_keys keys;
  92        int err = -EINVAL;
  93
  94        if (crypto_authenc_extractkeys(&keys, key, keylen) != 0)
  95                goto badkey;
  96
  97        crypto_ahash_clear_flags(auth, CRYPTO_TFM_REQ_MASK);
  98        crypto_ahash_set_flags(auth, crypto_aead_get_flags(authenc) &
  99                                    CRYPTO_TFM_REQ_MASK);
 100        err = crypto_ahash_setkey(auth, keys.authkey, keys.authkeylen);
 101        crypto_aead_set_flags(authenc, crypto_ahash_get_flags(auth) &
 102                                       CRYPTO_TFM_RES_MASK);
 103
 104        if (err)
 105                goto out;
 106
 107        crypto_ablkcipher_clear_flags(enc, CRYPTO_TFM_REQ_MASK);
 108        crypto_ablkcipher_set_flags(enc, crypto_aead_get_flags(authenc) &
 109                                         CRYPTO_TFM_REQ_MASK);
 110        err = crypto_ablkcipher_setkey(enc, keys.enckey, keys.enckeylen);
 111        crypto_aead_set_flags(authenc, crypto_ablkcipher_get_flags(enc) &
 112                                       CRYPTO_TFM_RES_MASK);
 113
 114out:
 115        return err;
 116
 117badkey:
 118        crypto_aead_set_flags(authenc, CRYPTO_TFM_RES_BAD_KEY_LEN);
 119        goto out;
 120}
 121
 122static void authenc_geniv_ahash_update_done(struct crypto_async_request *areq,
 123                                            int err)
 124{
 125        struct aead_request *req = areq->data;
 126        struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 127        struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
 128        struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
 129        struct ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
 130
 131        if (err)
 132                goto out;
 133
 134        ahash_request_set_crypt(ahreq, areq_ctx->sg, ahreq->result,
 135                                areq_ctx->cryptlen);
 136        ahash_request_set_callback(ahreq, aead_request_flags(req) &
 137                                          CRYPTO_TFM_REQ_MAY_SLEEP,
 138                                   areq_ctx->complete, req);
 139
 140        err = crypto_ahash_finup(ahreq);
 141        if (err)
 142                goto out;
 143
 144        scatterwalk_map_and_copy(ahreq->result, areq_ctx->sg,
 145                                 areq_ctx->cryptlen,
 146                                 crypto_aead_authsize(authenc), 1);
 147
 148out:
 149        authenc_request_complete(req, err);
 150}
 151
 152static void authenc_geniv_ahash_done(struct crypto_async_request *areq, int err)
 153{
 154        struct aead_request *req = areq->data;
 155        struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 156        struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
 157        struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
 158        struct ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
 159
 160        if (err)
 161                goto out;
 162
 163        scatterwalk_map_and_copy(ahreq->result, areq_ctx->sg,
 164                                 areq_ctx->cryptlen,
 165                                 crypto_aead_authsize(authenc), 1);
 166
 167out:
 168        aead_request_complete(req, err);
 169}
 170
 171static void authenc_verify_ahash_update_done(struct crypto_async_request *areq,
 172                                             int err)
 173{
 174        u8 *ihash;
 175        unsigned int authsize;
 176        struct ablkcipher_request *abreq;
 177        struct aead_request *req = areq->data;
 178        struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 179        struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
 180        struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
 181        struct ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
 182        unsigned int cryptlen = req->cryptlen;
 183
 184        if (err)
 185                goto out;
 186
 187        ahash_request_set_crypt(ahreq, areq_ctx->sg, ahreq->result,
 188                                areq_ctx->cryptlen);
 189        ahash_request_set_callback(ahreq, aead_request_flags(req) &
 190                                          CRYPTO_TFM_REQ_MAY_SLEEP,
 191                                   areq_ctx->complete, req);
 192
 193        err = crypto_ahash_finup(ahreq);
 194        if (err)
 195                goto out;
 196
 197        authsize = crypto_aead_authsize(authenc);
 198        cryptlen -= authsize;
 199        ihash = ahreq->result + authsize;
 200        scatterwalk_map_and_copy(ihash, areq_ctx->sg, areq_ctx->cryptlen,
 201                                 authsize, 0);
 202
 203        err = crypto_memneq(ihash, ahreq->result, authsize) ? -EBADMSG : 0;
 204        if (err)
 205                goto out;
 206
 207        abreq = aead_request_ctx(req);
 208        ablkcipher_request_set_tfm(abreq, ctx->enc);
 209        ablkcipher_request_set_callback(abreq, aead_request_flags(req),
 210                                        req->base.complete, req->base.data);
 211        ablkcipher_request_set_crypt(abreq, req->src, req->dst,
 212                                     cryptlen, req->iv);
 213
 214        err = crypto_ablkcipher_decrypt(abreq);
 215
 216out:
 217        authenc_request_complete(req, err);
 218}
 219
 220static void authenc_verify_ahash_done(struct crypto_async_request *areq,
 221                                      int err)
 222{
 223        u8 *ihash;
 224        unsigned int authsize;
 225        struct ablkcipher_request *abreq;
 226        struct aead_request *req = areq->data;
 227        struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 228        struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
 229        struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
 230        struct ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
 231        unsigned int cryptlen = req->cryptlen;
 232
 233        if (err)
 234                goto out;
 235
 236        authsize = crypto_aead_authsize(authenc);
 237        cryptlen -= authsize;
 238        ihash = ahreq->result + authsize;
 239        scatterwalk_map_and_copy(ihash, areq_ctx->sg, areq_ctx->cryptlen,
 240                                 authsize, 0);
 241
 242        err = crypto_memneq(ihash, ahreq->result, authsize) ? -EBADMSG : 0;
 243        if (err)
 244                goto out;
 245
 246        abreq = aead_request_ctx(req);
 247        ablkcipher_request_set_tfm(abreq, ctx->enc);
 248        ablkcipher_request_set_callback(abreq, aead_request_flags(req),
 249                                        req->base.complete, req->base.data);
 250        ablkcipher_request_set_crypt(abreq, req->src, req->dst,
 251                                     cryptlen, req->iv);
 252
 253        err = crypto_ablkcipher_decrypt(abreq);
 254
 255out:
 256        authenc_request_complete(req, err);
 257}
 258
 259static u8 *crypto_authenc_ahash_fb(struct aead_request *req, unsigned int flags)
 260{
 261        struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 262        struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
 263        struct crypto_ahash *auth = ctx->auth;
 264        struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
 265        struct ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
 266        u8 *hash = areq_ctx->tail;
 267        int err;
 268
 269        hash = (u8 *)ALIGN((unsigned long)hash + crypto_ahash_alignmask(auth),
 270                            crypto_ahash_alignmask(auth) + 1);
 271
 272        ahash_request_set_tfm(ahreq, auth);
 273
 274        err = crypto_ahash_init(ahreq);
 275        if (err)
 276                return ERR_PTR(err);
 277
 278        ahash_request_set_crypt(ahreq, req->assoc, hash, req->assoclen);
 279        ahash_request_set_callback(ahreq, aead_request_flags(req) & flags,
 280                                   areq_ctx->update_complete, req);
 281
 282        err = crypto_ahash_update(ahreq);
 283        if (err)
 284                return ERR_PTR(err);
 285
 286        ahash_request_set_crypt(ahreq, areq_ctx->sg, hash,
 287                                areq_ctx->cryptlen);
 288        ahash_request_set_callback(ahreq, aead_request_flags(req) & flags,
 289                                   areq_ctx->complete, req);
 290
 291        err = crypto_ahash_finup(ahreq);
 292        if (err)
 293                return ERR_PTR(err);
 294
 295        return hash;
 296}
 297
 298static u8 *crypto_authenc_ahash(struct aead_request *req, unsigned int flags)
 299{
 300        struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 301        struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
 302        struct crypto_ahash *auth = ctx->auth;
 303        struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
 304        struct ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
 305        u8 *hash = areq_ctx->tail;
 306        int err;
 307
 308        hash = (u8 *)ALIGN((unsigned long)hash + crypto_ahash_alignmask(auth),
 309                           crypto_ahash_alignmask(auth) + 1);
 310
 311        ahash_request_set_tfm(ahreq, auth);
 312        ahash_request_set_crypt(ahreq, areq_ctx->sg, hash,
 313                                areq_ctx->cryptlen);
 314        ahash_request_set_callback(ahreq, aead_request_flags(req) & flags,
 315                                   areq_ctx->complete, req);
 316
 317        err = crypto_ahash_digest(ahreq);
 318        if (err)
 319                return ERR_PTR(err);
 320
 321        return hash;
 322}
 323
 324static int crypto_authenc_genicv(struct aead_request *req, u8 *iv,
 325                                 unsigned int flags)
 326{
 327        struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 328        struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
 329        struct scatterlist *dst = req->dst;
 330        struct scatterlist *assoc = req->assoc;
 331        struct scatterlist *cipher = areq_ctx->cipher;
 332        struct scatterlist *asg = areq_ctx->asg;
 333        unsigned int ivsize = crypto_aead_ivsize(authenc);
 334        unsigned int cryptlen = req->cryptlen;
 335        authenc_ahash_t authenc_ahash_fn = crypto_authenc_ahash_fb;
 336        struct page *dstp;
 337        u8 *vdst;
 338        u8 *hash;
 339
 340        dstp = sg_page(dst);
 341        vdst = PageHighMem(dstp) ? NULL : page_address(dstp) + dst->offset;
 342
 343        if (ivsize) {
 344                sg_init_table(cipher, 2);
 345                sg_set_buf(cipher, iv, ivsize);
 346                scatterwalk_crypto_chain(cipher, dst, vdst == iv + ivsize, 2);
 347                dst = cipher;
 348                cryptlen += ivsize;
 349        }
 350
 351        if (req->assoclen && sg_is_last(assoc)) {
 352                authenc_ahash_fn = crypto_authenc_ahash;
 353                sg_init_table(asg, 2);
 354                sg_set_page(asg, sg_page(assoc), assoc->length, assoc->offset);
 355                scatterwalk_crypto_chain(asg, dst, 0, 2);
 356                dst = asg;
 357                cryptlen += req->assoclen;
 358        }
 359
 360        areq_ctx->cryptlen = cryptlen;
 361        areq_ctx->sg = dst;
 362
 363        areq_ctx->complete = authenc_geniv_ahash_done;
 364        areq_ctx->update_complete = authenc_geniv_ahash_update_done;
 365
 366        hash = authenc_ahash_fn(req, flags);
 367        if (IS_ERR(hash))
 368                return PTR_ERR(hash);
 369
 370        scatterwalk_map_and_copy(hash, dst, cryptlen,
 371                                 crypto_aead_authsize(authenc), 1);
 372        return 0;
 373}
 374
 375static void crypto_authenc_encrypt_done(struct crypto_async_request *req,
 376                                        int err)
 377{
 378        struct aead_request *areq = req->data;
 379
 380        if (!err) {
 381                struct crypto_aead *authenc = crypto_aead_reqtfm(areq);
 382                struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
 383                struct authenc_request_ctx *areq_ctx = aead_request_ctx(areq);
 384                struct ablkcipher_request *abreq = (void *)(areq_ctx->tail
 385                                                            + ctx->reqoff);
 386                u8 *iv = (u8 *)abreq - crypto_ablkcipher_ivsize(ctx->enc);
 387
 388                err = crypto_authenc_genicv(areq, iv, 0);
 389        }
 390
 391        authenc_request_complete(areq, err);
 392}
 393
 394static int crypto_authenc_encrypt(struct aead_request *req)
 395{
 396        struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 397        struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
 398        struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
 399        struct crypto_ablkcipher *enc = ctx->enc;
 400        struct scatterlist *dst = req->dst;
 401        unsigned int cryptlen = req->cryptlen;
 402        struct ablkcipher_request *abreq = (void *)(areq_ctx->tail
 403                                                    + ctx->reqoff);
 404        u8 *iv = (u8 *)abreq - crypto_ablkcipher_ivsize(enc);
 405        int err;
 406
 407        ablkcipher_request_set_tfm(abreq, enc);
 408        ablkcipher_request_set_callback(abreq, aead_request_flags(req),
 409                                        crypto_authenc_encrypt_done, req);
 410        ablkcipher_request_set_crypt(abreq, req->src, dst, cryptlen, req->iv);
 411
 412        memcpy(iv, req->iv, crypto_aead_ivsize(authenc));
 413
 414        err = crypto_ablkcipher_encrypt(abreq);
 415        if (err)
 416                return err;
 417
 418        return crypto_authenc_genicv(req, iv, CRYPTO_TFM_REQ_MAY_SLEEP);
 419}
 420
 421static void crypto_authenc_givencrypt_done(struct crypto_async_request *req,
 422                                           int err)
 423{
 424        struct aead_request *areq = req->data;
 425
 426        if (!err) {
 427                struct skcipher_givcrypt_request *greq = aead_request_ctx(areq);
 428
 429                err = crypto_authenc_genicv(areq, greq->giv, 0);
 430        }
 431
 432        authenc_request_complete(areq, err);
 433}
 434
 435static int crypto_authenc_givencrypt(struct aead_givcrypt_request *req)
 436{
 437        struct crypto_aead *authenc = aead_givcrypt_reqtfm(req);
 438        struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
 439        struct aead_request *areq = &req->areq;
 440        struct skcipher_givcrypt_request *greq = aead_request_ctx(areq);
 441        u8 *iv = req->giv;
 442        int err;
 443
 444        skcipher_givcrypt_set_tfm(greq, ctx->enc);
 445        skcipher_givcrypt_set_callback(greq, aead_request_flags(areq),
 446                                       crypto_authenc_givencrypt_done, areq);
 447        skcipher_givcrypt_set_crypt(greq, areq->src, areq->dst, areq->cryptlen,
 448                                    areq->iv);
 449        skcipher_givcrypt_set_giv(greq, iv, req->seq);
 450
 451        err = crypto_skcipher_givencrypt(greq);
 452        if (err)
 453                return err;
 454
 455        return crypto_authenc_genicv(areq, iv, CRYPTO_TFM_REQ_MAY_SLEEP);
 456}
 457
 458static int crypto_authenc_verify(struct aead_request *req,
 459                                 authenc_ahash_t authenc_ahash_fn)
 460{
 461        struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 462        struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
 463        u8 *ohash;
 464        u8 *ihash;
 465        unsigned int authsize;
 466
 467        areq_ctx->complete = authenc_verify_ahash_done;
 468        areq_ctx->update_complete = authenc_verify_ahash_update_done;
 469
 470        ohash = authenc_ahash_fn(req, CRYPTO_TFM_REQ_MAY_SLEEP);
 471        if (IS_ERR(ohash))
 472                return PTR_ERR(ohash);
 473
 474        authsize = crypto_aead_authsize(authenc);
 475        ihash = ohash + authsize;
 476        scatterwalk_map_and_copy(ihash, areq_ctx->sg, areq_ctx->cryptlen,
 477                                 authsize, 0);
 478        return crypto_memneq(ihash, ohash, authsize) ? -EBADMSG : 0;
 479}
 480
 481static int crypto_authenc_iverify(struct aead_request *req, u8 *iv,
 482                                  unsigned int cryptlen)
 483{
 484        struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 485        struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
 486        struct scatterlist *src = req->src;
 487        struct scatterlist *assoc = req->assoc;
 488        struct scatterlist *cipher = areq_ctx->cipher;
 489        struct scatterlist *asg = areq_ctx->asg;
 490        unsigned int ivsize = crypto_aead_ivsize(authenc);
 491        authenc_ahash_t authenc_ahash_fn = crypto_authenc_ahash_fb;
 492        struct page *srcp;
 493        u8 *vsrc;
 494
 495        srcp = sg_page(src);
 496        vsrc = PageHighMem(srcp) ? NULL : page_address(srcp) + src->offset;
 497
 498        if (ivsize) {
 499                sg_init_table(cipher, 2);
 500                sg_set_buf(cipher, iv, ivsize);
 501                scatterwalk_crypto_chain(cipher, src, vsrc == iv + ivsize, 2);
 502                src = cipher;
 503                cryptlen += ivsize;
 504        }
 505
 506        if (req->assoclen && sg_is_last(assoc)) {
 507                authenc_ahash_fn = crypto_authenc_ahash;
 508                sg_init_table(asg, 2);
 509                sg_set_page(asg, sg_page(assoc), assoc->length, assoc->offset);
 510                scatterwalk_crypto_chain(asg, src, 0, 2);
 511                src = asg;
 512                cryptlen += req->assoclen;
 513        }
 514
 515        areq_ctx->cryptlen = cryptlen;
 516        areq_ctx->sg = src;
 517
 518        return crypto_authenc_verify(req, authenc_ahash_fn);
 519}
 520
 521static int crypto_authenc_decrypt(struct aead_request *req)
 522{
 523        struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 524        struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
 525        struct ablkcipher_request *abreq = aead_request_ctx(req);
 526        unsigned int cryptlen = req->cryptlen;
 527        unsigned int authsize = crypto_aead_authsize(authenc);
 528        u8 *iv = req->iv;
 529        int err;
 530
 531        if (cryptlen < authsize)
 532                return -EINVAL;
 533        cryptlen -= authsize;
 534
 535        err = crypto_authenc_iverify(req, iv, cryptlen);
 536        if (err)
 537                return err;
 538
 539        ablkcipher_request_set_tfm(abreq, ctx->enc);
 540        ablkcipher_request_set_callback(abreq, aead_request_flags(req),
 541                                        req->base.complete, req->base.data);
 542        ablkcipher_request_set_crypt(abreq, req->src, req->dst, cryptlen, iv);
 543
 544        return crypto_ablkcipher_decrypt(abreq);
 545}
 546
 547static int crypto_authenc_init_tfm(struct crypto_tfm *tfm)
 548{
 549        struct crypto_instance *inst = crypto_tfm_alg_instance(tfm);
 550        struct authenc_instance_ctx *ictx = crypto_instance_ctx(inst);
 551        struct crypto_authenc_ctx *ctx = crypto_tfm_ctx(tfm);
 552        struct crypto_ahash *auth;
 553        struct crypto_ablkcipher *enc;
 554        int err;
 555
 556        auth = crypto_spawn_ahash(&ictx->auth);
 557        if (IS_ERR(auth))
 558                return PTR_ERR(auth);
 559
 560        enc = crypto_spawn_skcipher(&ictx->enc);
 561        err = PTR_ERR(enc);
 562        if (IS_ERR(enc))
 563                goto err_free_ahash;
 564
 565        ctx->auth = auth;
 566        ctx->enc = enc;
 567
 568        ctx->reqoff = ALIGN(2 * crypto_ahash_digestsize(auth) +
 569                            crypto_ahash_alignmask(auth),
 570                            crypto_ahash_alignmask(auth) + 1) +
 571                      crypto_ablkcipher_ivsize(enc);
 572
 573        tfm->crt_aead.reqsize = sizeof(struct authenc_request_ctx) +
 574                                ctx->reqoff +
 575                                max_t(unsigned int,
 576                                crypto_ahash_reqsize(auth) +
 577                                sizeof(struct ahash_request),
 578                                sizeof(struct skcipher_givcrypt_request) +
 579                                crypto_ablkcipher_reqsize(enc));
 580
 581        return 0;
 582
 583err_free_ahash:
 584        crypto_free_ahash(auth);
 585        return err;
 586}
 587
 588static void crypto_authenc_exit_tfm(struct crypto_tfm *tfm)
 589{
 590        struct crypto_authenc_ctx *ctx = crypto_tfm_ctx(tfm);
 591
 592        crypto_free_ahash(ctx->auth);
 593        crypto_free_ablkcipher(ctx->enc);
 594}
 595
 596static struct crypto_instance *crypto_authenc_alloc(struct rtattr **tb)
 597{
 598        struct crypto_attr_type *algt;
 599        struct crypto_instance *inst;
 600        struct hash_alg_common *auth;
 601        struct crypto_alg *auth_base;
 602        struct crypto_alg *enc;
 603        struct authenc_instance_ctx *ctx;
 604        const char *enc_name;
 605        int err;
 606
 607        algt = crypto_get_attr_type(tb);
 608        if (IS_ERR(algt))
 609                return ERR_CAST(algt);
 610
 611        if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
 612                return ERR_PTR(-EINVAL);
 613
 614        auth = ahash_attr_alg(tb[1], CRYPTO_ALG_TYPE_HASH,
 615                               CRYPTO_ALG_TYPE_AHASH_MASK);
 616        if (IS_ERR(auth))
 617                return ERR_CAST(auth);
 618
 619        auth_base = &auth->base;
 620
 621        enc_name = crypto_attr_alg_name(tb[2]);
 622        err = PTR_ERR(enc_name);
 623        if (IS_ERR(enc_name))
 624                goto out_put_auth;
 625
 626        inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
 627        err = -ENOMEM;
 628        if (!inst)
 629                goto out_put_auth;
 630
 631        ctx = crypto_instance_ctx(inst);
 632
 633        err = crypto_init_ahash_spawn(&ctx->auth, auth, inst);
 634        if (err)
 635                goto err_free_inst;
 636
 637        crypto_set_skcipher_spawn(&ctx->enc, inst);
 638        err = crypto_grab_skcipher(&ctx->enc, enc_name, 0,
 639                                   crypto_requires_sync(algt->type,
 640                                                        algt->mask));
 641        if (err)
 642                goto err_drop_auth;
 643
 644        enc = crypto_skcipher_spawn_alg(&ctx->enc);
 645
 646        err = -ENAMETOOLONG;
 647        if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME,
 648                     "authenc(%s,%s)", auth_base->cra_name, enc->cra_name) >=
 649            CRYPTO_MAX_ALG_NAME)
 650                goto err_drop_enc;
 651
 652        if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
 653                     "authenc(%s,%s)", auth_base->cra_driver_name,
 654                     enc->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
 655                goto err_drop_enc;
 656
 657        inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD;
 658        inst->alg.cra_flags |= enc->cra_flags & CRYPTO_ALG_ASYNC;
 659        inst->alg.cra_priority = enc->cra_priority *
 660                                 10 + auth_base->cra_priority;
 661        inst->alg.cra_blocksize = enc->cra_blocksize;
 662        inst->alg.cra_alignmask = auth_base->cra_alignmask | enc->cra_alignmask;
 663        inst->alg.cra_type = &crypto_aead_type;
 664
 665        inst->alg.cra_aead.ivsize = enc->cra_ablkcipher.ivsize;
 666        inst->alg.cra_aead.maxauthsize = auth->digestsize;
 667
 668        inst->alg.cra_ctxsize = sizeof(struct crypto_authenc_ctx);
 669
 670        inst->alg.cra_init = crypto_authenc_init_tfm;
 671        inst->alg.cra_exit = crypto_authenc_exit_tfm;
 672
 673        inst->alg.cra_aead.setkey = crypto_authenc_setkey;
 674        inst->alg.cra_aead.encrypt = crypto_authenc_encrypt;
 675        inst->alg.cra_aead.decrypt = crypto_authenc_decrypt;
 676        inst->alg.cra_aead.givencrypt = crypto_authenc_givencrypt;
 677
 678out:
 679        crypto_mod_put(auth_base);
 680        return inst;
 681
 682err_drop_enc:
 683        crypto_drop_skcipher(&ctx->enc);
 684err_drop_auth:
 685        crypto_drop_ahash(&ctx->auth);
 686err_free_inst:
 687        kfree(inst);
 688out_put_auth:
 689        inst = ERR_PTR(err);
 690        goto out;
 691}
 692
 693static void crypto_authenc_free(struct crypto_instance *inst)
 694{
 695        struct authenc_instance_ctx *ctx = crypto_instance_ctx(inst);
 696
 697        crypto_drop_skcipher(&ctx->enc);
 698        crypto_drop_ahash(&ctx->auth);
 699        kfree(inst);
 700}
 701
 702static struct crypto_template crypto_authenc_tmpl = {
 703        .name = "authenc",
 704        .alloc = crypto_authenc_alloc,
 705        .free = crypto_authenc_free,
 706        .module = THIS_MODULE,
 707};
 708
 709static int __init crypto_authenc_module_init(void)
 710{
 711        return crypto_register_template(&crypto_authenc_tmpl);
 712}
 713
 714static void __exit crypto_authenc_module_exit(void)
 715{
 716        crypto_unregister_template(&crypto_authenc_tmpl);
 717}
 718
 719module_init(crypto_authenc_module_init);
 720module_exit(crypto_authenc_module_exit);
 721
 722MODULE_LICENSE("GPL");
 723MODULE_DESCRIPTION("Simple AEAD wrapper for IPsec");
 724MODULE_ALIAS_CRYPTO("authenc");
 725