crypto/gcm.c

   1 /*
   2  * GCM: Galois/Counter Mode.
   3  *
   4  * Copyright (c) 2007 Nokia Siemens Networks - Mikko Herranen <mh1@iki.fi>
   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 version 2 as published
   8  * by the Free Software Foundation.
   9  */
  10
  11 #include <crypto/gf128mul.h>
  12 #include <crypto/internal/aead.h>
  13 #include <crypto/internal/skcipher.h>
  14 #include <crypto/internal/hash.h>
  15 #include <crypto/scatterwalk.h>
  16 #include <crypto/hash.h>
  17 #include "internal.h"
  18 #include <linux/completion.h>
  19 #include <linux/err.h>
  20 #include <linux/init.h>
  21 #include <linux/kernel.h>
  22 #include <linux/module.h>
  23 #include <linux/slab.h>
  24
  25 struct gcm_instance_ctx {
  26         struct crypto_skcipher_spawn ctr;
  27         struct crypto_ahash_spawn ghash;
  28 };
  29
  30 struct crypto_gcm_ctx {
  31         struct crypto_ablkcipher *ctr;
  32         struct crypto_ahash *ghash;
  33 };
  34
  35 struct crypto_rfc4106_ctx {
  36         struct crypto_aead *child;
  37         u8 nonce[4];
  38 };
  39
  40 struct crypto_gcm_ghash_ctx {
  41         unsigned int cryptlen;
  42         struct scatterlist *src;
  43         crypto_completion_t complete;
  44 };
  45
  46 struct crypto_gcm_req_priv_ctx {
  47         u8 auth_tag[16];
  48         u8 iauth_tag[16];
  49         struct scatterlist src[2];
  50         struct scatterlist dst[2];
  51         struct crypto_gcm_ghash_ctx ghash_ctx;
  52         union {
  53                 struct ahash_request ahreq;
  54                 struct ablkcipher_request abreq;
  55         } u;
  56 };
  57
  58 struct crypto_gcm_setkey_result {
  59         int err;
  60         struct completion completion;
  61 };
  62
  63 static void *gcm_zeroes;
  64
  65 static inline struct crypto_gcm_req_priv_ctx *crypto_gcm_reqctx(
  66         struct aead_request *req)
  67 {
  68         unsigned long align = crypto_aead_alignmask(crypto_aead_reqtfm(req));
  69
  70         return (void *)PTR_ALIGN((u8 *)aead_request_ctx(req), align + 1);
  71 }
  72
  73 static void crypto_gcm_setkey_done(struct crypto_async_request *req, int err)
  74 {
  75         struct crypto_gcm_setkey_result *result = req->data;
  76
  77         if (err == -EINPROGRESS)
  78                 return;
  79
  80         result->err = err;
  81         complete(&result->completion);
  82 }
  83
  84 static int crypto_gcm_setkey(struct crypto_aead *aead, const u8 *key,
  85                              unsigned int keylen)
  86 {
  87         struct crypto_gcm_ctx *ctx = crypto_aead_ctx(aead);
  88         struct crypto_ahash *ghash = ctx->ghash;
  89         struct crypto_ablkcipher *ctr = ctx->ctr;
  90         struct {
  91                 be128 hash;
  92                 u8 iv[8];
  93
  94                 struct crypto_gcm_setkey_result result;
  95
  96                 struct scatterlist sg[1];
  97                 struct ablkcipher_request req;
  98         } *data;
  99         int err;
 100
 101         crypto_ablkcipher_clear_flags(ctr, CRYPTO_TFM_REQ_MASK);
 102         crypto_ablkcipher_set_flags(ctr, crypto_aead_get_flags(aead) &
 103                                    CRYPTO_TFM_REQ_MASK);
 104
 105         err = crypto_ablkcipher_setkey(ctr, key, keylen);
 106         if (err)
 107                 return err;
 108
 109         crypto_aead_set_flags(aead, crypto_ablkcipher_get_flags(ctr) &
 110                                        CRYPTO_TFM_RES_MASK);
 111
 112         data = kzalloc(sizeof(*data) + crypto_ablkcipher_reqsize(ctr),
 113                        GFP_KERNEL);
 114         if (!data)
 115                 return -ENOMEM;
 116
 117         init_completion(&data->result.completion);
 118         sg_init_one(data->sg, &data->hash, sizeof(data->hash));
 119         ablkcipher_request_set_tfm(&data->req, ctr);
 120         ablkcipher_request_set_callback(&data->req, CRYPTO_TFM_REQ_MAY_SLEEP |
 121                                                     CRYPTO_TFM_REQ_MAY_BACKLOG,
 122                                         crypto_gcm_setkey_done,
 123                                         &data->result);
 124         ablkcipher_request_set_crypt(&data->req, data->sg, data->sg,
 125                                      sizeof(data->hash), data->iv);
 126
 127         err = crypto_ablkcipher_encrypt(&data->req);
 128         if (err == -EINPROGRESS || err == -EBUSY) {
 129                 err = wait_for_completion_interruptible(
 130                         &data->result.completion);
 131                 if (!err)
 132                         err = data->result.err;
 133         }
 134
 135         if (err)
 136                 goto out;
 137
 138         crypto_ahash_clear_flags(ghash, CRYPTO_TFM_REQ_MASK);
 139         crypto_ahash_set_flags(ghash, crypto_aead_get_flags(aead) &
 140                                CRYPTO_TFM_REQ_MASK);
 141         err = crypto_ahash_setkey(ghash, (u8 *)&data->hash, sizeof(be128));
 142         crypto_aead_set_flags(aead, crypto_ahash_get_flags(ghash) &
 143                               CRYPTO_TFM_RES_MASK);
 144
 145 out:
 146         kfree(data);
 147         return err;
 148 }
 149
 150 static int crypto_gcm_setauthsize(struct crypto_aead *tfm,
 151                                   unsigned int authsize)
 152 {
 153         switch (authsize) {
 154         case 4:
 155         case 8:
 156         case 12:
 157         case 13:
 158         case 14:
 159         case 15:
 160         case 16:
 161                 break;
 162         default:
 163                 return -EINVAL;
 164         }
 165
 166         return 0;
 167 }
 168
 169 static void crypto_gcm_init_crypt(struct ablkcipher_request *ablk_req,
 170                                   struct aead_request *req,
 171                                   unsigned int cryptlen)
 172 {
 173         struct crypto_aead *aead = crypto_aead_reqtfm(req);
 174         struct crypto_gcm_ctx *ctx = crypto_aead_ctx(aead);
 175         struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
 176         struct scatterlist *dst;
 177         __be32 counter = cpu_to_be32(1);
 178
 179         memset(pctx->auth_tag, 0, sizeof(pctx->auth_tag));
 180         memcpy(req->iv + 12, &counter, 4);
 181
 182         sg_init_table(pctx->src, 2);
 183         sg_set_buf(pctx->src, pctx->auth_tag, sizeof(pctx->auth_tag));
 184         scatterwalk_sg_chain(pctx->src, 2, req->src);
 185
 186         dst = pctx->src;
 187         if (req->src != req->dst) {
 188                 sg_init_table(pctx->dst, 2);
 189                 sg_set_buf(pctx->dst, pctx->auth_tag, sizeof(pctx->auth_tag));
 190                 scatterwalk_sg_chain(pctx->dst, 2, req->dst);
 191                 dst = pctx->dst;
 192         }
 193
 194         ablkcipher_request_set_tfm(ablk_req, ctx->ctr);
 195         ablkcipher_request_set_crypt(ablk_req, pctx->src, dst,
 196                                      cryptlen + sizeof(pctx->auth_tag),
 197                                      req->iv);
 198 }
 199
 200 static inline unsigned int gcm_remain(unsigned int len)
 201 {
 202         len &= 0xfU;
 203         return len ? 16 - len : 0;
 204 }
 205
 206 static void gcm_hash_len_done(struct crypto_async_request *areq, int err);
 207 static void gcm_hash_final_done(struct crypto_async_request *areq, int err);
 208
 209 static int gcm_hash_update(struct aead_request *req,
 210                            struct crypto_gcm_req_priv_ctx *pctx,
 211                            crypto_completion_t complete,
 212                            struct scatterlist *src,
 213                            unsigned int len)
 214 {
 215         struct ahash_request *ahreq = &pctx->u.ahreq;
 216
 217         ahash_request_set_callback(ahreq, aead_request_flags(req),
 218                                    complete, req);
 219         ahash_request_set_crypt(ahreq, src, NULL, len);
 220
 221         return crypto_ahash_update(ahreq);
 222 }
 223
 224 static int gcm_hash_remain(struct aead_request *req,
 225                            struct crypto_gcm_req_priv_ctx *pctx,
 226                            unsigned int remain,
 227                            crypto_completion_t complete)
 228 {
 229         struct ahash_request *ahreq = &pctx->u.ahreq;
 230
 231         ahash_request_set_callback(ahreq, aead_request_flags(req),
 232                                    complete, req);
 233         sg_init_one(pctx->src, gcm_zeroes, remain);
 234         ahash_request_set_crypt(ahreq, pctx->src, NULL, remain);
 235
 236         return crypto_ahash_update(ahreq);
 237 }
 238
 239 static int gcm_hash_len(struct aead_request *req,
 240                         struct crypto_gcm_req_priv_ctx *pctx)
 241 {
 242         struct ahash_request *ahreq = &pctx->u.ahreq;
 243         struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx;
 244         u128 lengths;
 245
 246         lengths.a = cpu_to_be64(req->assoclen * 8);
 247         lengths.b = cpu_to_be64(gctx->cryptlen * 8);
 248         memcpy(pctx->iauth_tag, &lengths, 16);
 249         sg_init_one(pctx->src, pctx->iauth_tag, 16);
 250         ahash_request_set_callback(ahreq, aead_request_flags(req),
 251                                    gcm_hash_len_done, req);
 252         ahash_request_set_crypt(ahreq, pctx->src,
 253                                 NULL, sizeof(lengths));
 254
 255         return crypto_ahash_update(ahreq);
 256 }
 257
 258 static int gcm_hash_final(struct aead_request *req,
 259                           struct crypto_gcm_req_priv_ctx *pctx)
 260 {
 261         struct ahash_request *ahreq = &pctx->u.ahreq;
 262
 263         ahash_request_set_callback(ahreq, aead_request_flags(req),
 264                                    gcm_hash_final_done, req);
 265         ahash_request_set_crypt(ahreq, NULL, pctx->iauth_tag, 0);
 266
 267         return crypto_ahash_final(ahreq);
 268 }
 269
 270 static void gcm_hash_final_done(struct crypto_async_request *areq,
 271                                 int err)
 272 {
 273         struct aead_request *req = areq->data;
 274         struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
 275         struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx;
 276
 277         if (!err)
 278                 crypto_xor(pctx->auth_tag, pctx->iauth_tag, 16);
 279
 280         gctx->complete(areq, err);
 281 }
 282
 283 static void gcm_hash_len_done(struct crypto_async_request *areq,
 284                               int err)
 285 {
 286         struct aead_request *req = areq->data;
 287         struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
 288
 289         if (!err) {
 290                 err = gcm_hash_final(req, pctx);
 291                 if (err == -EINPROGRESS || err == -EBUSY)
 292                         return;
 293         }
 294
 295         gcm_hash_final_done(areq, err);
 296 }
 297
 298 static void gcm_hash_crypt_remain_done(struct crypto_async_request *areq,
 299                                        int err)
 300 {
 301         struct aead_request *req = areq->data;
 302         struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
 303
 304         if (!err) {
 305                 err = gcm_hash_len(req, pctx);
 306                 if (err == -EINPROGRESS || err == -EBUSY)
 307                         return;
 308         }
 309
 310         gcm_hash_len_done(areq, err);
 311 }
 312
 313 static void gcm_hash_crypt_done(struct crypto_async_request *areq,
 314                                 int err)
 315 {
 316         struct aead_request *req = areq->data;
 317         struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
 318         struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx;
 319         unsigned int remain;
 320
 321         if (!err) {
 322                 remain = gcm_remain(gctx->cryptlen);
 323                 BUG_ON(!remain);
 324                 err = gcm_hash_remain(req, pctx, remain,
 325                                       gcm_hash_crypt_remain_done);
 326                 if (err == -EINPROGRESS || err == -EBUSY)
 327                         return;
 328         }
 329
 330         gcm_hash_crypt_remain_done(areq, err);
 331 }
 332
 333 static void gcm_hash_assoc_remain_done(struct crypto_async_request *areq,
 334                                            int err)
 335 {
 336         struct aead_request *req = areq->data;
 337         struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
 338         struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx;
 339         crypto_completion_t complete;
 340         unsigned int remain = 0;
 341
 342         if (!err && gctx->cryptlen) {
 343                 remain = gcm_remain(gctx->cryptlen);
 344                 complete = remain ? gcm_hash_crypt_done :
 345                         gcm_hash_crypt_remain_done;
 346                 err = gcm_hash_update(req, pctx, complete,
 347                                       gctx->src, gctx->cryptlen);
 348                 if (err == -EINPROGRESS || err == -EBUSY)
 349                         return;
 350         }
 351
 352         if (remain)
 353                 gcm_hash_crypt_done(areq, err);
 354         else
 355                 gcm_hash_crypt_remain_done(areq, err);
 356 }
 357
 358 static void gcm_hash_assoc_done(struct crypto_async_request *areq,
 359                                 int err)
 360 {
 361         struct aead_request *req = areq->data;
 362         struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
 363         unsigned int remain;
 364
 365         if (!err) {
 366                 remain = gcm_remain(req->assoclen);
 367                 BUG_ON(!remain);
 368                 err = gcm_hash_remain(req, pctx, remain,
 369                                       gcm_hash_assoc_remain_done);
 370                 if (err == -EINPROGRESS || err == -EBUSY)
 371                         return;
 372         }
 373
 374         gcm_hash_assoc_remain_done(areq, err);
 375 }
 376
 377 static void gcm_hash_init_done(struct crypto_async_request *areq,
 378                                int err)
 379 {
 380         struct aead_request *req = areq->data;
 381         struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
 382         crypto_completion_t complete;
 383         unsigned int remain = 0;
 384
 385         if (!err && req->assoclen) {
 386                 remain = gcm_remain(req->assoclen);
 387                 complete = remain ? gcm_hash_assoc_done :
 388                         gcm_hash_assoc_remain_done;
 389                 err = gcm_hash_update(req, pctx, complete,
 390                                       req->assoc, req->assoclen);
 391                 if (err == -EINPROGRESS || err == -EBUSY)
 392                         return;
 393         }
 394
 395         if (remain)
 396                 gcm_hash_assoc_done(areq, err);
 397         else
 398                 gcm_hash_assoc_remain_done(areq, err);
 399 }
 400
 401 static int gcm_hash(struct aead_request *req,
 402                     struct crypto_gcm_req_priv_ctx *pctx)
 403 {
 404         struct ahash_request *ahreq = &pctx->u.ahreq;
 405         struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx;
 406         struct crypto_gcm_ctx *ctx = crypto_tfm_ctx(req->base.tfm);
 407         unsigned int remain;
 408         crypto_completion_t complete;
 409         int err;
 410
 411         ahash_request_set_tfm(ahreq, ctx->ghash);
 412
 413         ahash_request_set_callback(ahreq, aead_request_flags(req),
 414                                    gcm_hash_init_done, req);
 415         err = crypto_ahash_init(ahreq);
 416         if (err)
 417                 return err;
 418         remain = gcm_remain(req->assoclen);
 419         complete = remain ? gcm_hash_assoc_done : gcm_hash_assoc_remain_done;
 420         err = gcm_hash_update(req, pctx, complete, req->assoc, req->assoclen);
 421         if (err)
 422                 return err;
 423         if (remain) {
 424                 err = gcm_hash_remain(req, pctx, remain,
 425                                       gcm_hash_assoc_remain_done);
 426                 if (err)
 427                         return err;
 428         }
 429         remain = gcm_remain(gctx->cryptlen);
 430         complete = remain ? gcm_hash_crypt_done : gcm_hash_crypt_remain_done;
 431         err = gcm_hash_update(req, pctx, complete, gctx->src, gctx->cryptlen);
 432         if (err)
 433                 return err;
 434         if (remain) {
 435                 err = gcm_hash_remain(req, pctx, remain,
 436                                       gcm_hash_crypt_remain_done);
 437                 if (err)
 438                         return err;
 439         }
 440         err = gcm_hash_len(req, pctx);
 441         if (err)
 442                 return err;
 443         err = gcm_hash_final(req, pctx);
 444         if (err)
 445                 return err;
 446
 447         return 0;
 448 }
 449
 450 static void gcm_enc_copy_hash(struct aead_request *req,
 451                               struct crypto_gcm_req_priv_ctx *pctx)
 452 {
 453         struct crypto_aead *aead = crypto_aead_reqtfm(req);
 454         u8 *auth_tag = pctx->auth_tag;
 455
 456         scatterwalk_map_and_copy(auth_tag, req->dst, req->cryptlen,
 457                                  crypto_aead_authsize(aead), 1);
 458 }
 459
 460 static void gcm_enc_hash_done(struct crypto_async_request *areq,
 461                                      int err)
 462 {
 463         struct aead_request *req = areq->data;
 464         struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
 465
 466         if (!err)
 467                 gcm_enc_copy_hash(req, pctx);
 468
 469         aead_request_complete(req, err);
 470 }
 471
 472 static void gcm_encrypt_done(struct crypto_async_request *areq,
 473                                      int err)
 474 {
 475         struct aead_request *req = areq->data;
 476         struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
 477
 478         if (!err) {
 479                 err = gcm_hash(req, pctx);
 480                 if (err == -EINPROGRESS || err == -EBUSY)
 481                         return;
 482         }
 483
 484         gcm_enc_hash_done(areq, err);
 485 }
 486
 487 static int crypto_gcm_encrypt(struct aead_request *req)
 488 {
 489         struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
 490         struct ablkcipher_request *abreq = &pctx->u.abreq;
 491         struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx;
 492         int err;
 493
 494         crypto_gcm_init_crypt(abreq, req, req->cryptlen);
 495         ablkcipher_request_set_callback(abreq, aead_request_flags(req),
 496                                         gcm_encrypt_done, req);
 497
 498         gctx->src = req->dst;
 499         gctx->cryptlen = req->cryptlen;
 500         gctx->complete = gcm_enc_hash_done;
 501
 502         err = crypto_ablkcipher_encrypt(abreq);
 503         if (err)
 504                 return err;
 505
 506         err = gcm_hash(req, pctx);
 507         if (err)
 508                 return err;
 509
 510         crypto_xor(pctx->auth_tag, pctx->iauth_tag, 16);
 511         gcm_enc_copy_hash(req, pctx);
 512
 513         return 0;
 514 }
 515
 516 static int crypto_gcm_verify(struct aead_request *req,
 517                              struct crypto_gcm_req_priv_ctx *pctx)
 518 {
 519         struct crypto_aead *aead = crypto_aead_reqtfm(req);
 520         u8 *auth_tag = pctx->auth_tag;
 521         u8 *iauth_tag = pctx->iauth_tag;
 522         unsigned int authsize = crypto_aead_authsize(aead);
 523         unsigned int cryptlen = req->cryptlen - authsize;
 524
 525         crypto_xor(auth_tag, iauth_tag, 16);
 526         scatterwalk_map_and_copy(iauth_tag, req->src, cryptlen, authsize, 0);
 527         return memcmp(iauth_tag, auth_tag, authsize) ? -EBADMSG : 0;
 528 }
 529
 530 static void gcm_decrypt_done(struct crypto_async_request *areq, int err)
 531 {
 532         struct aead_request *req = areq->data;
 533         struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
 534
 535         if (!err)
 536                 err = crypto_gcm_verify(req, pctx);
 537
 538         aead_request_complete(req, err);
 539 }
 540
 541 static void gcm_dec_hash_done(struct crypto_async_request *areq, int err)
 542 {
 543         struct aead_request *req = areq->data;
 544         struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
 545         struct ablkcipher_request *abreq = &pctx->u.abreq;
 546         struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx;
 547
 548         if (!err) {
 549                 ablkcipher_request_set_callback(abreq, aead_request_flags(req),
 550                                                 gcm_decrypt_done, req);
 551                 crypto_gcm_init_crypt(abreq, req, gctx->cryptlen);
 552                 err = crypto_ablkcipher_decrypt(abreq);
 553                 if (err == -EINPROGRESS || err == -EBUSY)
 554                         return;
 555         }
 556
 557         gcm_decrypt_done(areq, err);
 558 }
 559
 560 static int crypto_gcm_decrypt(struct aead_request *req)
 561 {
 562         struct crypto_aead *aead = crypto_aead_reqtfm(req);
 563         struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
 564         struct ablkcipher_request *abreq = &pctx->u.abreq;
 565         struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx;
 566         unsigned int authsize = crypto_aead_authsize(aead);
 567         unsigned int cryptlen = req->cryptlen;
 568         int err;
 569
 570         if (cryptlen < authsize)
 571                 return -EINVAL;
 572         cryptlen -= authsize;
 573
 574         gctx->src = req->src;
 575         gctx->cryptlen = cryptlen;
 576         gctx->complete = gcm_dec_hash_done;
 577
 578         err = gcm_hash(req, pctx);
 579         if (err)
 580                 return err;
 581
 582         ablkcipher_request_set_callback(abreq, aead_request_flags(req),
 583                                         gcm_decrypt_done, req);
 584         crypto_gcm_init_crypt(abreq, req, cryptlen);
 585         err = crypto_ablkcipher_decrypt(abreq);
 586         if (err)
 587                 return err;
 588
 589         return crypto_gcm_verify(req, pctx);
 590 }
 591
 592 static int crypto_gcm_init_tfm(struct crypto_tfm *tfm)
 593 {
 594         struct crypto_instance *inst = (void *)tfm->__crt_alg;
 595         struct gcm_instance_ctx *ictx = crypto_instance_ctx(inst);
 596         struct crypto_gcm_ctx *ctx = crypto_tfm_ctx(tfm);
 597         struct crypto_ablkcipher *ctr;
 598         struct crypto_ahash *ghash;
 599         unsigned long align;
 600         int err;
 601
 602         ghash = crypto_spawn_ahash(&ictx->ghash);
 603         if (IS_ERR(ghash))
 604                 return PTR_ERR(ghash);
 605
 606         ctr = crypto_spawn_skcipher(&ictx->ctr);
 607         err = PTR_ERR(ctr);
 608         if (IS_ERR(ctr))
 609                 goto err_free_hash;
 610
 611         ctx->ctr = ctr;
 612         ctx->ghash = ghash;
 613
 614         align = crypto_tfm_alg_alignmask(tfm);
 615         align &= ~(crypto_tfm_ctx_alignment() - 1);
 616         tfm->crt_aead.reqsize = align +
 617                 offsetof(struct crypto_gcm_req_priv_ctx, u) +
 618                 max(sizeof(struct ablkcipher_request) +
 619                     crypto_ablkcipher_reqsize(ctr),
 620                     sizeof(struct ahash_request) +
 621                     crypto_ahash_reqsize(ghash));
 622
 623         return 0;
 624
 625 err_free_hash:
 626         crypto_free_ahash(ghash);
 627         return err;
 628 }
 629
 630 static void crypto_gcm_exit_tfm(struct crypto_tfm *tfm)
 631 {
 632         struct crypto_gcm_ctx *ctx = crypto_tfm_ctx(tfm);
 633
 634         crypto_free_ahash(ctx->ghash);
 635         crypto_free_ablkcipher(ctx->ctr);
 636 }
 637
 638 static struct crypto_instance *crypto_gcm_alloc_common(struct rtattr **tb,
 639                                                        const char *full_name,
 640                                                        const char *ctr_name,
 641                                                        const char *ghash_name)
 642 {
 643         struct crypto_attr_type *algt;
 644         struct crypto_instance *inst;
 645         struct crypto_alg *ctr;
 646         struct crypto_alg *ghash_alg;
 647         struct ahash_alg *ghash_ahash_alg;
 648         struct gcm_instance_ctx *ctx;
 649         int err;
 650
 651         algt = crypto_get_attr_type(tb);
 652         err = PTR_ERR(algt);
 653         if (IS_ERR(algt))
 654                 return ERR_PTR(err);
 655
 656         if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
 657                 return ERR_PTR(-EINVAL);
 658
 659         ghash_alg = crypto_find_alg(ghash_name, &crypto_ahash_type,
 660                                     CRYPTO_ALG_TYPE_HASH,
 661                                     CRYPTO_ALG_TYPE_AHASH_MASK);
 662         err = PTR_ERR(ghash_alg);
 663         if (IS_ERR(ghash_alg))
 664                 return ERR_PTR(err);
 665
 666         err = -ENOMEM;
 667         inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
 668         if (!inst)
 669                 goto out_put_ghash;
 670
 671         ctx = crypto_instance_ctx(inst);
 672         ghash_ahash_alg = container_of(ghash_alg, struct ahash_alg, halg.base);
 673         err = crypto_init_ahash_spawn(&ctx->ghash, &ghash_ahash_alg->halg,
 674                                       inst);
 675         if (err)
 676                 goto err_free_inst;
 677
 678         crypto_set_skcipher_spawn(&ctx->ctr, inst);
 679         err = crypto_grab_skcipher(&ctx->ctr, ctr_name, 0,
 680                                    crypto_requires_sync(algt->type,
 681                                                         algt->mask));
 682         if (err)
 683                 goto err_drop_ghash;
 684
 685         ctr = crypto_skcipher_spawn_alg(&ctx->ctr);
 686
 687         /* We only support 16-byte blocks. */
 688         if (ctr->cra_ablkcipher.ivsize != 16)
 689                 goto out_put_ctr;
 690
 691         /* Not a stream cipher? */
 692         err = -EINVAL;
 693         if (ctr->cra_blocksize != 1)
 694                 goto out_put_ctr;
 695
 696         err = -ENAMETOOLONG;
 697         if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
 698                      "gcm_base(%s,%s)", ctr->cra_driver_name,
 699                      ghash_alg->cra_driver_name) >=
 700             CRYPTO_MAX_ALG_NAME)
 701                 goto out_put_ctr;
 702
 703         memcpy(inst->alg.cra_name, full_name, CRYPTO_MAX_ALG_NAME);
 704
 705         inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD;
 706         inst->alg.cra_flags |= ctr->cra_flags & CRYPTO_ALG_ASYNC;
 707         inst->alg.cra_priority = ctr->cra_priority;
 708         inst->alg.cra_blocksize = 1;
 709         inst->alg.cra_alignmask = ctr->cra_alignmask | (__alignof__(u64) - 1);
 710         inst->alg.cra_type = &crypto_aead_type;
 711         inst->alg.cra_aead.ivsize = 16;
 712         inst->alg.cra_aead.maxauthsize = 16;
 713         inst->alg.cra_ctxsize = sizeof(struct crypto_gcm_ctx);
 714         inst->alg.cra_init = crypto_gcm_init_tfm;
 715         inst->alg.cra_exit = crypto_gcm_exit_tfm;
 716         inst->alg.cra_aead.setkey = crypto_gcm_setkey;
 717         inst->alg.cra_aead.setauthsize = crypto_gcm_setauthsize;
 718         inst->alg.cra_aead.encrypt = crypto_gcm_encrypt;
 719         inst->alg.cra_aead.decrypt = crypto_gcm_decrypt;
 720
 721 out:
 722         crypto_mod_put(ghash_alg);
 723         return inst;
 724
 725 out_put_ctr:
 726         crypto_drop_skcipher(&ctx->ctr);
 727 err_drop_ghash:
 728         crypto_drop_ahash(&ctx->ghash);
 729 err_free_inst:
 730         kfree(inst);
 731 out_put_ghash:
 732         inst = ERR_PTR(err);
 733         goto out;
 734 }
 735
 736 static struct crypto_instance *crypto_gcm_alloc(struct rtattr **tb)
 737 {
 738         int err;
 739         const char *cipher_name;
 740         char ctr_name[CRYPTO_MAX_ALG_NAME];
 741         char full_name[CRYPTO_MAX_ALG_NAME];
 742
 743         cipher_name = crypto_attr_alg_name(tb[1]);
 744         err = PTR_ERR(cipher_name);
 745         if (IS_ERR(cipher_name))
 746                 return ERR_PTR(err);
 747
 748         if (snprintf(ctr_name, CRYPTO_MAX_ALG_NAME, "ctr(%s)", cipher_name) >=
 749             CRYPTO_MAX_ALG_NAME)
 750                 return ERR_PTR(-ENAMETOOLONG);
 751
 752         if (snprintf(full_name, CRYPTO_MAX_ALG_NAME, "gcm(%s)", cipher_name) >=
 753             CRYPTO_MAX_ALG_NAME)
 754                 return ERR_PTR(-ENAMETOOLONG);
 755
 756         return crypto_gcm_alloc_common(tb, full_name, ctr_name, "ghash");
 757 }
 758
 759 static void crypto_gcm_free(struct crypto_instance *inst)
 760 {
 761         struct gcm_instance_ctx *ctx = crypto_instance_ctx(inst);
 762
 763         crypto_drop_skcipher(&ctx->ctr);
 764         crypto_drop_ahash(&ctx->ghash);
 765         kfree(inst);
 766 }
 767
 768 static struct crypto_template crypto_gcm_tmpl = {
 769         .name = "gcm",
 770         .alloc = crypto_gcm_alloc,
 771         .free = crypto_gcm_free,
 772         .module = THIS_MODULE,
 773 };
 774
 775 static struct crypto_instance *crypto_gcm_base_alloc(struct rtattr **tb)
 776 {
 777         int err;
 778         const char *ctr_name;
 779         const char *ghash_name;
 780         char full_name[CRYPTO_MAX_ALG_NAME];
 781
 782         ctr_name = crypto_attr_alg_name(tb[1]);
 783         err = PTR_ERR(ctr_name);
 784         if (IS_ERR(ctr_name))
 785                 return ERR_PTR(err);
 786
 787         ghash_name = crypto_attr_alg_name(tb[2]);
 788         err = PTR_ERR(ghash_name);
 789         if (IS_ERR(ghash_name))
 790                 return ERR_PTR(err);
 791
 792         if (snprintf(full_name, CRYPTO_MAX_ALG_NAME, "gcm_base(%s,%s)",
 793                      ctr_name, ghash_name) >= CRYPTO_MAX_ALG_NAME)
 794                 return ERR_PTR(-ENAMETOOLONG);
 795
 796         return crypto_gcm_alloc_common(tb, full_name, ctr_name, ghash_name);
 797 }
 798
 799 static struct crypto_template crypto_gcm_base_tmpl = {
 800         .name = "gcm_base",
 801         .alloc = crypto_gcm_base_alloc,
 802         .free = crypto_gcm_free,
 803         .module = THIS_MODULE,
 804 };
 805
 806 static int crypto_rfc4106_setkey(struct crypto_aead *parent, const u8 *key,
 807                                  unsigned int keylen)
 808 {
 809         struct crypto_rfc4106_ctx *ctx = crypto_aead_ctx(parent);
 810         struct crypto_aead *child = ctx->child;
 811         int err;
 812
 813         if (keylen < 4)
 814                 return -EINVAL;
 815
 816         keylen -= 4;
 817         memcpy(ctx->nonce, key + keylen, 4);
 818
 819         crypto_aead_clear_flags(child, CRYPTO_TFM_REQ_MASK);
 820         crypto_aead_set_flags(child, crypto_aead_get_flags(parent) &
 821                                      CRYPTO_TFM_REQ_MASK);
 822         err = crypto_aead_setkey(child, key, keylen);
 823         crypto_aead_set_flags(parent, crypto_aead_get_flags(child) &
 824                                       CRYPTO_TFM_RES_MASK);
 825
 826         return err;
 827 }
 828
 829 static int crypto_rfc4106_setauthsize(struct crypto_aead *parent,
 830                                       unsigned int authsize)
 831 {
 832         struct crypto_rfc4106_ctx *ctx = crypto_aead_ctx(parent);
 833
 834         switch (authsize) {
 835         case 8:
 836         case 12:
 837         case 16:
 838                 break;
 839         default:
 840                 return -EINVAL;
 841         }
 842
 843         return crypto_aead_setauthsize(ctx->child, authsize);
 844 }
 845
 846 static struct aead_request *crypto_rfc4106_crypt(struct aead_request *req)
 847 {
 848         struct aead_request *subreq = aead_request_ctx(req);
 849         struct crypto_aead *aead = crypto_aead_reqtfm(req);
 850         struct crypto_rfc4106_ctx *ctx = crypto_aead_ctx(aead);
 851         struct crypto_aead *child = ctx->child;
 852         u8 *iv = PTR_ALIGN((u8 *)(subreq + 1) + crypto_aead_reqsize(child),
 853                            crypto_aead_alignmask(child) + 1);
 854
 855         memcpy(iv, ctx->nonce, 4);
 856         memcpy(iv + 4, req->iv, 8);
 857
 858         aead_request_set_tfm(subreq, child);
 859         aead_request_set_callback(subreq, req->base.flags, req->base.complete,
 860                                   req->base.data);
 861         aead_request_set_crypt(subreq, req->src, req->dst, req->cryptlen, iv);
 862         aead_request_set_assoc(subreq, req->assoc, req->assoclen);
 863
 864         return subreq;
 865 }
 866
 867 static int crypto_rfc4106_encrypt(struct aead_request *req)
 868 {
 869         req = crypto_rfc4106_crypt(req);
 870
 871         return crypto_aead_encrypt(req);
 872 }
 873
 874 static int crypto_rfc4106_decrypt(struct aead_request *req)
 875 {
 876         req = crypto_rfc4106_crypt(req);
 877
 878         return crypto_aead_decrypt(req);
 879 }
 880
 881 static int crypto_rfc4106_init_tfm(struct crypto_tfm *tfm)
 882 {
 883         struct crypto_instance *inst = (void *)tfm->__crt_alg;
 884         struct crypto_aead_spawn *spawn = crypto_instance_ctx(inst);
 885         struct crypto_rfc4106_ctx *ctx = crypto_tfm_ctx(tfm);
 886         struct crypto_aead *aead;
 887         unsigned long align;
 888
 889         aead = crypto_spawn_aead(spawn);
 890         if (IS_ERR(aead))
 891                 return PTR_ERR(aead);
 892
 893         ctx->child = aead;
 894
 895         align = crypto_aead_alignmask(aead);
 896         align &= ~(crypto_tfm_ctx_alignment() - 1);
 897         tfm->crt_aead.reqsize = sizeof(struct aead_request) +
 898                                 ALIGN(crypto_aead_reqsize(aead),
 899                                       crypto_tfm_ctx_alignment()) +
 900                                 align + 16;
 901
 902         return 0;
 903 }
 904
 905 static void crypto_rfc4106_exit_tfm(struct crypto_tfm *tfm)
 906 {
 907         struct crypto_rfc4106_ctx *ctx = crypto_tfm_ctx(tfm);
 908
 909         crypto_free_aead(ctx->child);
 910 }
 911
 912 static struct crypto_instance *crypto_rfc4106_alloc(struct rtattr **tb)
 913 {
 914         struct crypto_attr_type *algt;
 915         struct crypto_instance *inst;
 916         struct crypto_aead_spawn *spawn;
 917         struct crypto_alg *alg;
 918         const char *ccm_name;
 919         int err;
 920
 921         algt = crypto_get_attr_type(tb);
 922         err = PTR_ERR(algt);
 923         if (IS_ERR(algt))
 924                 return ERR_PTR(err);
 925
 926         if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
 927                 return ERR_PTR(-EINVAL);
 928
 929         ccm_name = crypto_attr_alg_name(tb[1]);
 930         err = PTR_ERR(ccm_name);
 931         if (IS_ERR(ccm_name))
 932                 return ERR_PTR(err);
 933
 934         inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
 935         if (!inst)
 936                 return ERR_PTR(-ENOMEM);
 937
 938         spawn = crypto_instance_ctx(inst);
 939         crypto_set_aead_spawn(spawn, inst);
 940         err = crypto_grab_aead(spawn, ccm_name, 0,
 941                                crypto_requires_sync(algt->type, algt->mask));
 942         if (err)
 943                 goto out_free_inst;
 944
 945         alg = crypto_aead_spawn_alg(spawn);
 946
 947         err = -EINVAL;
 948
 949         /* We only support 16-byte blocks. */
 950         if (alg->cra_aead.ivsize != 16)
 951                 goto out_drop_alg;
 952
 953         /* Not a stream cipher? */
 954         if (alg->cra_blocksize != 1)
 955                 goto out_drop_alg;
 956
 957         err = -ENAMETOOLONG;
 958         if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME,
 959                      "rfc4106(%s)", alg->cra_name) >= CRYPTO_MAX_ALG_NAME ||
 960             snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
 961                      "rfc4106(%s)", alg->cra_driver_name) >=
 962             CRYPTO_MAX_ALG_NAME)
 963                 goto out_drop_alg;
 964
 965         inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD;
 966         inst->alg.cra_flags |= alg->cra_flags & CRYPTO_ALG_ASYNC;
 967         inst->alg.cra_priority = alg->cra_priority;
 968         inst->alg.cra_blocksize = 1;
 969         inst->alg.cra_alignmask = alg->cra_alignmask;
 970         inst->alg.cra_type = &crypto_nivaead_type;
 971
 972         inst->alg.cra_aead.ivsize = 8;
 973         inst->alg.cra_aead.maxauthsize = 16;
 974
 975         inst->alg.cra_ctxsize = sizeof(struct crypto_rfc4106_ctx);
 976
 977         inst->alg.cra_init = crypto_rfc4106_init_tfm;
 978         inst->alg.cra_exit = crypto_rfc4106_exit_tfm;
 979
 980         inst->alg.cra_aead.setkey = crypto_rfc4106_setkey;
 981         inst->alg.cra_aead.setauthsize = crypto_rfc4106_setauthsize;
 982         inst->alg.cra_aead.encrypt = crypto_rfc4106_encrypt;
 983         inst->alg.cra_aead.decrypt = crypto_rfc4106_decrypt;
 984
 985         inst->alg.cra_aead.geniv = "seqiv";
 986
 987 out:
 988         return inst;
 989
 990 out_drop_alg:
 991         crypto_drop_aead(spawn);
 992 out_free_inst:
 993         kfree(inst);
 994         inst = ERR_PTR(err);
 995         goto out;
 996 }
 997
 998 static void crypto_rfc4106_free(struct crypto_instance *inst)
 999 {
1000         crypto_drop_spawn(crypto_instance_ctx(inst));
1001         kfree(inst);
1002 }
1003
1004 static struct crypto_template crypto_rfc4106_tmpl = {
1005         .name = "rfc4106",
1006         .alloc = crypto_rfc4106_alloc,
1007         .free = crypto_rfc4106_free,
1008         .module = THIS_MODULE,
1009 };
1010
1011 static int __init crypto_gcm_module_init(void)
1012 {
1013         int err;
1014
1015         gcm_zeroes = kzalloc(16, GFP_KERNEL);
1016         if (!gcm_zeroes)
1017                 return -ENOMEM;
1018
1019         err = crypto_register_template(&crypto_gcm_base_tmpl);
1020         if (err)
1021                 goto out;
1022
1023         err = crypto_register_template(&crypto_gcm_tmpl);
1024         if (err)
1025                 goto out_undo_base;
1026
1027         err = crypto_register_template(&crypto_rfc4106_tmpl);
1028         if (err)
1029                 goto out_undo_gcm;
1030
1031         return 0;
1032
1033 out_undo_gcm:
1034         crypto_unregister_template(&crypto_gcm_tmpl);
1035 out_undo_base:
1036         crypto_unregister_template(&crypto_gcm_base_tmpl);
1037 out:
1038         kfree(gcm_zeroes);
1039         return err;
1040 }
1041
1042 static void __exit crypto_gcm_module_exit(void)
1043 {
1044         kfree(gcm_zeroes);
1045         crypto_unregister_template(&crypto_rfc4106_tmpl);
1046         crypto_unregister_template(&crypto_gcm_tmpl);
1047         crypto_unregister_template(&crypto_gcm_base_tmpl);
1048 }
1049
1050 module_init(crypto_gcm_module_init);
1051 module_exit(crypto_gcm_module_exit);
1052
1053 MODULE_LICENSE("GPL");
1054 MODULE_DESCRIPTION("Galois/Counter Mode");
1055 MODULE_AUTHOR("Mikko Herranen <mh1@iki.fi>");
1056 MODULE_ALIAS("gcm_base");
1057 MODULE_ALIAS("rfc4106");