lustre/ptlrpc/gss/gss_sk_mech.c

   1 /*
   2  * GPL HEADER START
   3  *
   4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 only,
   8  * as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * General Public License version 2 for more details (a copy is included
  14  * in the LICENSE file that accompanied this code).
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * version 2 along with this program; If not, see
  18  * http://www.gnu.org/licenses/gpl-2.0.html
  19  *
  20  * GPL HEADER END
  21  */
  22 /*
  23  * Copyright (C) 2013, 2015, Trustees of Indiana University
  24  *
  25  * Copyright (c) 2014, 2016, Intel Corporation.
  26  *
  27  * Author: Jeremy Filizetti <jfilizet@iu.edu>
  28  * Author: Andrew Korty <ajk@iu.edu>
  29  */
  30
  31 #define DEBUG_SUBSYSTEM S_SEC
  32 #include <linux/init.h>
  33 #include <linux/module.h>
  34 #include <linux/slab.h>
  35 #include <linux/crypto.h>
  36 #include <linux/mutex.h>
  37 #include <crypto/ctr.h>
  38
  39 #include <obd.h>
  40 #include <obd_class.h>
  41 #include <obd_support.h>
  42
  43 #include "gss_err.h"
  44 #include "gss_crypto.h"
  45 #include "gss_internal.h"
  46 #include "gss_api.h"
  47 #include "gss_asn1.h"
  48
  49 #define SK_INTERFACE_VERSION 1
  50 #define SK_MSG_VERSION 1
  51 #define SK_MIN_SIZE 8
  52 #define SK_IV_SIZE 16
  53
  54 /* Starting number for reverse contexts.  It is critical to security
  55  * that reverse contexts use a different range of numbers than regular
  56  * contexts because they are using the same key.  Therefore the IV/nonce
  57  * combination must be unique for them.  To accomplish this reverse contexts
  58  * use the the negative range of a 64-bit number and regular contexts use the
  59  * postive range.  If the same IV/nonce combination were reused it would leak
  60  * information about the plaintext. */
  61 #define SK_IV_REV_START (1ULL << 63)
  62
  63 struct sk_ctx {
  64         enum cfs_crypto_crypt_alg sc_crypt;
  65         enum cfs_crypto_hash_alg  sc_hmac;
  66         __u32                     sc_expire;
  67         __u32                     sc_host_random;
  68         __u32                     sc_peer_random;
  69         atomic64_t                sc_iv;
  70         rawobj_t                  sc_hmac_key;
  71         struct gss_keyblock       sc_session_kb;
  72 };
  73
  74 struct sk_hdr {
  75         __u64                   skh_version;
  76         __u64                   skh_iv;
  77 } __attribute__((packed));
  78
  79 /* The format of SK wire data is similar to that of RFC3686 ESP Payload
  80  * (section 3) except instead of just an IV there is a struct sk_hdr.
  81  * ---------------------------------------------------------------------
  82  * | struct sk_hdr | ciphertext (variable size) | HMAC (variable size) |
  83  * --------------------------------------------------------------------- */
  84 struct sk_wire {
  85         rawobj_t                skw_header;
  86         rawobj_t                skw_cipher;
  87         rawobj_t                skw_hmac;
  88 };
  89
  90 static inline unsigned long sk_block_mask(unsigned long len, int blocksize)
  91 {
  92         return (len + blocksize - 1) & (~(blocksize - 1));
  93 }
  94
  95 static int sk_fill_header(struct sk_ctx *skc, struct sk_hdr *skh)
  96 {
  97         __u64 tmp_iv;
  98         skh->skh_version = be64_to_cpu(SK_MSG_VERSION);
  99
 100         /* Always using inc_return so we don't use our initial numbers which
 101          * could be the reuse detecting numbers */
 102         tmp_iv = atomic64_inc_return(&skc->sc_iv);
 103         skh->skh_iv = be64_to_cpu(tmp_iv);
 104         if (tmp_iv == 0 || tmp_iv == SK_IV_REV_START) {
 105                 CERROR("Counter looped, connection must be reset to avoid "
 106                        "plaintext information\n");
 107                 return GSS_S_FAILURE;
 108         }
 109
 110         return GSS_S_COMPLETE;
 111 }
 112
 113 static int sk_verify_header(struct sk_hdr *skh)
 114 {
 115         if (cpu_to_be64(skh->skh_version) != SK_MSG_VERSION)
 116                 return GSS_S_DEFECTIVE_TOKEN;
 117
 118         return GSS_S_COMPLETE;
 119 }
 120
 121 void sk_construct_rfc3686_iv(__u8 *iv, __u32 nonce, __u64 partial_iv)
 122 {
 123         __u32 ctr = cpu_to_be32(1);
 124
 125         memcpy(iv, &nonce, CTR_RFC3686_NONCE_SIZE);
 126         iv += CTR_RFC3686_NONCE_SIZE;
 127         memcpy(iv, &partial_iv, CTR_RFC3686_IV_SIZE);
 128         iv += CTR_RFC3686_IV_SIZE;
 129         memcpy(iv, &ctr, sizeof(ctr));
 130 }
 131
 132 static int sk_fill_context(rawobj_t *inbuf, struct sk_ctx *skc)
 133 {
 134         char *ptr = inbuf->data;
 135         char *end = inbuf->data + inbuf->len;
 136         char sk_hmac[CRYPTO_MAX_ALG_NAME];
 137         char sk_crypt[CRYPTO_MAX_ALG_NAME];
 138         u32 tmp;
 139
 140         /* see sk_serialize_kctx() for format from userspace side */
 141         /*  1. Version */
 142         if (gss_get_bytes(&ptr, end, &tmp, sizeof(tmp))) {
 143                 CERROR("Failed to read shared key interface version\n");
 144                 return -1;
 145         }
 146         if (tmp != SK_INTERFACE_VERSION) {
 147                 CERROR("Invalid shared key interface version: %d\n", tmp);
 148                 return -1;
 149         }
 150
 151         /* 2. HMAC type */
 152         if (gss_get_bytes(&ptr, end, &sk_hmac, sizeof(sk_hmac))) {
 153                 CERROR("Failed to read HMAC algorithm type\n");
 154                 return -1;
 155         }
 156
 157         skc->sc_hmac = cfs_crypto_hash_alg(sk_hmac);
 158         if (skc->sc_hmac != CFS_HASH_ALG_NULL &&
 159             skc->sc_hmac != CFS_HASH_ALG_SHA256 &&
 160             skc->sc_hmac != CFS_HASH_ALG_SHA512) {
 161                 CERROR("Invalid hmac type: %s\n", sk_hmac);
 162                 return -1;
 163         }
 164
 165         /* 3. crypt type */
 166         if (gss_get_bytes(&ptr, end, &sk_crypt, sizeof(sk_crypt))) {
 167                 CERROR("Failed to read crypt algorithm type\n");
 168                 return -1;
 169         }
 170
 171         skc->sc_crypt = cfs_crypto_crypt_alg(sk_crypt);
 172         if (skc->sc_crypt == CFS_CRYPT_ALG_UNKNOWN) {
 173                 CERROR("Invalid crypt type: %s\n", sk_crypt);
 174                 return -1;
 175         }
 176
 177         /* 4. expiration time */
 178         if (gss_get_bytes(&ptr, end, &tmp, sizeof(tmp))) {
 179                 CERROR("Failed to read context expiration time\n");
 180                 return -1;
 181         }
 182         skc->sc_expire = tmp + ktime_get_real_seconds();
 183
 184         /* 5. host random is used as nonce for encryption */
 185         if (gss_get_bytes(&ptr, end, &skc->sc_host_random,
 186                           sizeof(skc->sc_host_random))) {
 187                 CERROR("Failed to read host random\n");
 188                 return -1;
 189         }
 190
 191         /* 6. peer random is used as nonce for decryption */
 192         if (gss_get_bytes(&ptr, end, &skc->sc_peer_random,
 193                           sizeof(skc->sc_peer_random))) {
 194                 CERROR("Failed to read peer random\n");
 195                 return -1;
 196         }
 197
 198         /* 7. HMAC key */
 199         if (gss_get_rawobj(&ptr, end, &skc->sc_hmac_key)) {
 200                 CERROR("Failed to read HMAC key\n");
 201                 return -1;
 202         }
 203         if (skc->sc_hmac_key.len <= SK_MIN_SIZE) {
 204                 CERROR("HMAC key must key must be larger than %d bytes\n",
 205                        SK_MIN_SIZE);
 206                 return -1;
 207         }
 208
 209         /* 8. Session key, can be empty if not using privacy mode */
 210         if (gss_get_rawobj(&ptr, end, &skc->sc_session_kb.kb_key)) {
 211                 CERROR("Failed to read session key\n");
 212                 return -1;
 213         }
 214
 215         return 0;
 216 }
 217
 218 static void sk_delete_context(struct sk_ctx *skc)
 219 {
 220         if (!skc)
 221                 return;
 222
 223         rawobj_free(&skc->sc_hmac_key);
 224         gss_keyblock_free(&skc->sc_session_kb);
 225         OBD_FREE_PTR(skc);
 226 }
 227
 228 static
 229 __u32 gss_import_sec_context_sk(rawobj_t *inbuf, struct gss_ctx *gss_context)
 230 {
 231         struct sk_ctx *skc;
 232         bool privacy = false;
 233
 234         if (inbuf == NULL || inbuf->data == NULL)
 235                 return GSS_S_FAILURE;
 236
 237         OBD_ALLOC_PTR(skc);
 238         if (!skc)
 239                 return GSS_S_FAILURE;
 240
 241         atomic64_set(&skc->sc_iv, 0);
 242
 243         if (sk_fill_context(inbuf, skc))
 244                 goto out_err;
 245
 246         /* Only privacy mode needs to initialize keys */
 247         if (skc->sc_session_kb.kb_key.len > 0) {
 248                 privacy = true;
 249                 if (gss_keyblock_init(&skc->sc_session_kb,
 250                                       cfs_crypto_crypt_name(skc->sc_crypt), 0))
 251                         goto out_err;
 252         }
 253
 254         gss_context->internal_ctx_id = skc;
 255         CDEBUG(D_SEC, "successfully imported sk%s context\n",
 256                privacy ? " (with privacy)" : "");
 257
 258         return GSS_S_COMPLETE;
 259
 260 out_err:
 261         sk_delete_context(skc);
 262         return GSS_S_FAILURE;
 263 }
 264
 265 static
 266 __u32 gss_copy_reverse_context_sk(struct gss_ctx *gss_context_old,
 267                                   struct gss_ctx *gss_context_new)
 268 {
 269         struct sk_ctx *skc_old = gss_context_old->internal_ctx_id;
 270         struct sk_ctx *skc_new;
 271
 272         OBD_ALLOC_PTR(skc_new);
 273         if (!skc_new)
 274                 return GSS_S_FAILURE;
 275
 276         skc_new->sc_hmac = skc_old->sc_hmac;
 277         skc_new->sc_crypt = skc_old->sc_crypt;
 278         skc_new->sc_expire = skc_old->sc_expire;
 279         skc_new->sc_host_random = skc_old->sc_host_random;
 280         skc_new->sc_peer_random = skc_old->sc_peer_random;
 281
 282         atomic64_set(&skc_new->sc_iv, SK_IV_REV_START);
 283
 284         if (rawobj_dup(&skc_new->sc_hmac_key, &skc_old->sc_hmac_key))
 285                 goto out_err;
 286         if (gss_keyblock_dup(&skc_new->sc_session_kb, &skc_old->sc_session_kb))
 287                 goto out_err;
 288
 289         /* Only privacy mode needs to initialize keys */
 290         if (skc_new->sc_session_kb.kb_key.len > 0)
 291                 if (gss_keyblock_init(&skc_new->sc_session_kb,
 292                                       cfs_crypto_crypt_name(skc_new->sc_crypt),
 293                                       0))
 294                         goto out_err;
 295
 296         gss_context_new->internal_ctx_id = skc_new;
 297         CDEBUG(D_SEC, "successfully copied reverse sk context\n");
 298
 299         return GSS_S_COMPLETE;
 300
 301 out_err:
 302         sk_delete_context(skc_new);
 303         return GSS_S_FAILURE;
 304 }
 305
 306 static
 307 __u32 gss_inquire_context_sk(struct gss_ctx *gss_context,
 308                              time64_t *endtime)
 309 {
 310         struct sk_ctx *skc = gss_context->internal_ctx_id;
 311
 312         *endtime = skc->sc_expire;
 313         return GSS_S_COMPLETE;
 314 }
 315
 316 static
 317 u32 sk_make_hmac(enum cfs_crypto_hash_alg algo, rawobj_t *key, int msg_count,
 318                  rawobj_t *msgs, int iov_count, lnet_kiov_t *iovs,
 319                  rawobj_t *token, digest_hash hash_func)
 320 {
 321         struct ahash_request *req;
 322         int rc2, rc;
 323
 324         req = cfs_crypto_hash_init(algo, key->data, key->len);
 325         if (IS_ERR(req)) {
 326                 rc = PTR_ERR(req);
 327                 goto out_init_failed;
 328         }
 329
 330
 331         if (hash_func)
 332                 rc2 = hash_func(req, NULL, msg_count, msgs, iov_count,
 333                                 iovs);
 334         else
 335                 rc2 = gss_digest_hash(req, NULL, msg_count, msgs, iov_count,
 336                                       iovs);
 337
 338         rc = cfs_crypto_hash_final(req, token->data, &token->len);
 339         if (!rc && rc2)
 340                 rc = rc2;
 341 out_init_failed:
 342         return rc ? GSS_S_FAILURE : GSS_S_COMPLETE;
 343 }
 344
 345 static
 346 __u32 gss_get_mic_sk(struct gss_ctx *gss_context,
 347                      int message_count,
 348                      rawobj_t *messages,
 349                      int iov_count,
 350                      lnet_kiov_t *iovs,
 351                      rawobj_t *token)
 352 {
 353         struct sk_ctx *skc = gss_context->internal_ctx_id;
 354
 355         return sk_make_hmac(skc->sc_hmac,
 356                             &skc->sc_hmac_key, message_count, messages,
 357                             iov_count, iovs, token, gss_context->hash_func);
 358 }
 359
 360 static
 361 u32 sk_verify_hmac(enum cfs_crypto_hash_alg algo, rawobj_t *key,
 362                    int message_count, rawobj_t *messages,
 363                    int iov_count, lnet_kiov_t *iovs,
 364                    rawobj_t *token, digest_hash hash_func)
 365 {
 366         rawobj_t checksum = RAWOBJ_EMPTY;
 367         __u32 rc = GSS_S_FAILURE;
 368
 369         checksum.len = cfs_crypto_hash_digestsize(algo);
 370         if (token->len < checksum.len) {
 371                 CDEBUG(D_SEC, "Token received too short, expected %d "
 372                        "received %d\n", token->len, checksum.len);
 373                 return GSS_S_DEFECTIVE_TOKEN;
 374         }
 375
 376         OBD_ALLOC_LARGE(checksum.data, checksum.len);
 377         if (!checksum.data)
 378                 return rc;
 379
 380         if (sk_make_hmac(algo, key, message_count,
 381                          messages, iov_count, iovs, &checksum,
 382                          hash_func)) {
 383                 CDEBUG(D_SEC, "Failed to create checksum to validate\n");
 384                 goto cleanup;
 385         }
 386
 387         if (memcmp(token->data, checksum.data, checksum.len)) {
 388                 CERROR("checksum mismatch\n");
 389                 rc = GSS_S_BAD_SIG;
 390                 goto cleanup;
 391         }
 392
 393         rc = GSS_S_COMPLETE;
 394
 395 cleanup:
 396         OBD_FREE(checksum.data, checksum.len);
 397         return rc;
 398 }
 399
 400 /* sk_verify_bulk_hmac() differs slightly from sk_verify_hmac() because all
 401  * encrypted pages in the bulk descriptor are populated although we only need
 402  * to decrypt up to the number of bytes actually specified from the sender
 403  * (bd_nob) otherwise the calulated HMAC will be incorrect. */
 404 static
 405 u32 sk_verify_bulk_hmac(enum cfs_crypto_hash_alg sc_hmac, rawobj_t *key,
 406                         int msgcnt, rawobj_t *msgs, int iovcnt,
 407                         lnet_kiov_t *iovs, int iov_bytes, rawobj_t *token)
 408 {
 409         rawobj_t checksum = RAWOBJ_EMPTY;
 410         struct ahash_request *req;
 411         struct scatterlist sg[1];
 412         int rc = 0;
 413         struct sg_table sgt;
 414         int bytes;
 415         int i;
 416
 417         checksum.len = cfs_crypto_hash_digestsize(sc_hmac);
 418         if (token->len < checksum.len) {
 419                 CDEBUG(D_SEC, "Token received too short, expected %d "
 420                        "received %d\n", token->len, checksum.len);
 421                 return GSS_S_DEFECTIVE_TOKEN;
 422         }
 423
 424         OBD_ALLOC_LARGE(checksum.data, checksum.len);
 425         if (!checksum.data)
 426                 return GSS_S_FAILURE;
 427
 428         req = cfs_crypto_hash_init(sc_hmac, key->data, key->len);
 429         if (IS_ERR(req)) {
 430                 rc = GSS_S_FAILURE;
 431                 goto cleanup;
 432         }
 433
 434         for (i = 0; i < msgcnt; i++) {
 435                 if (!msgs[i].len)
 436                         continue;
 437
 438                 rc = gss_setup_sgtable(&sgt, sg, msgs[i].data, msgs[i].len);
 439                 if (rc != 0)
 440                         goto hash_cleanup;
 441
 442                 ahash_request_set_crypt(req, sg, NULL, msgs[i].len);
 443                 rc = crypto_ahash_update(req);
 444                 if (rc) {
 445                         gss_teardown_sgtable(&sgt);
 446                         goto hash_cleanup;
 447                 }
 448
 449                 gss_teardown_sgtable(&sgt);
 450         }
 451
 452         for (i = 0; i < iovcnt && iov_bytes > 0; i++) {
 453                 if (iovs[i].kiov_len == 0)
 454                         continue;
 455
 456                 bytes = min_t(int, iov_bytes, iovs[i].kiov_len);
 457                 iov_bytes -= bytes;
 458
 459                 sg_init_table(sg, 1);
 460                 sg_set_page(&sg[0], iovs[i].kiov_page, bytes,
 461                             iovs[i].kiov_offset);
 462                 ahash_request_set_crypt(req, sg, NULL, bytes);
 463                 rc = crypto_ahash_update(req);
 464                 if (rc)
 465                         goto hash_cleanup;
 466         }
 467
 468 hash_cleanup:
 469         cfs_crypto_hash_final(req, checksum.data, &checksum.len);
 470         if (rc)
 471                 goto cleanup;
 472
 473         if (memcmp(token->data, checksum.data, checksum.len))
 474                 rc = GSS_S_BAD_SIG;
 475         else
 476                 rc = GSS_S_COMPLETE;
 477
 478 cleanup:
 479         OBD_FREE_LARGE(checksum.data, checksum.len);
 480
 481         return rc;
 482 }
 483
 484 static
 485 __u32 gss_verify_mic_sk(struct gss_ctx *gss_context,
 486                         int message_count,
 487                         rawobj_t *messages,
 488                         int iov_count,
 489                         lnet_kiov_t *iovs,
 490                         rawobj_t *token)
 491 {
 492         struct sk_ctx *skc = gss_context->internal_ctx_id;
 493
 494         return sk_verify_hmac(skc->sc_hmac, &skc->sc_hmac_key,
 495                               message_count, messages, iov_count, iovs, token,
 496                               gss_context->hash_func);
 497 }
 498
 499 static
 500 __u32 gss_wrap_sk(struct gss_ctx *gss_context, rawobj_t *gss_header,
 501                     rawobj_t *message, int message_buffer_length,
 502                     rawobj_t *token)
 503 {
 504         struct sk_ctx *skc = gss_context->internal_ctx_id;
 505         size_t sht_bytes = cfs_crypto_hash_digestsize(skc->sc_hmac);
 506         struct sk_wire skw;
 507         struct sk_hdr skh;
 508         rawobj_t msgbufs[3];
 509         __u8 local_iv[SK_IV_SIZE];
 510         unsigned int blocksize;
 511
 512         LASSERT(skc->sc_session_kb.kb_tfm);
 513
 514         blocksize = crypto_blkcipher_blocksize(skc->sc_session_kb.kb_tfm);
 515         if (gss_add_padding(message, message_buffer_length, blocksize))
 516                 return GSS_S_FAILURE;
 517
 518         memset(token->data, 0, token->len);
 519
 520         if (sk_fill_header(skc, &skh) != GSS_S_COMPLETE)
 521                 return GSS_S_FAILURE;
 522
 523         skw.skw_header.data = token->data;
 524         skw.skw_header.len = sizeof(skh);
 525         memcpy(skw.skw_header.data, &skh, sizeof(skh));
 526
 527         sk_construct_rfc3686_iv(local_iv, skc->sc_host_random, skh.skh_iv);
 528         skw.skw_cipher.data = skw.skw_header.data + skw.skw_header.len;
 529         skw.skw_cipher.len = token->len - skw.skw_header.len - sht_bytes;
 530         if (gss_crypt_rawobjs(skc->sc_session_kb.kb_tfm, local_iv, 1, message,
 531                               &skw.skw_cipher, 1))
 532                 return GSS_S_FAILURE;
 533
 534         /* HMAC covers the SK header, GSS header, and ciphertext */
 535         msgbufs[0] = skw.skw_header;
 536         msgbufs[1] = *gss_header;
 537         msgbufs[2] = skw.skw_cipher;
 538
 539         skw.skw_hmac.data = skw.skw_cipher.data + skw.skw_cipher.len;
 540         skw.skw_hmac.len = sht_bytes;
 541         if (sk_make_hmac(skc->sc_hmac, &skc->sc_hmac_key,
 542                          3, msgbufs, 0, NULL, &skw.skw_hmac,
 543                          gss_context->hash_func))
 544                 return GSS_S_FAILURE;
 545
 546         token->len = skw.skw_header.len + skw.skw_cipher.len + skw.skw_hmac.len;
 547
 548         return GSS_S_COMPLETE;
 549 }
 550
 551 static
 552 __u32 gss_unwrap_sk(struct gss_ctx *gss_context, rawobj_t *gss_header,
 553                       rawobj_t *token, rawobj_t *message)
 554 {
 555         struct sk_ctx *skc = gss_context->internal_ctx_id;
 556         size_t sht_bytes = cfs_crypto_hash_digestsize(skc->sc_hmac);
 557         struct sk_wire skw;
 558         struct sk_hdr *skh;
 559         rawobj_t msgbufs[3];
 560         __u8 local_iv[SK_IV_SIZE];
 561         unsigned int blocksize;
 562         int rc;
 563
 564         LASSERT(skc->sc_session_kb.kb_tfm);
 565
 566         if (token->len < sizeof(skh) + sht_bytes)
 567                 return GSS_S_DEFECTIVE_TOKEN;
 568
 569         skw.skw_header.data = token->data;
 570         skw.skw_header.len = sizeof(struct sk_hdr);
 571         skw.skw_cipher.data = skw.skw_header.data + skw.skw_header.len;
 572         skw.skw_cipher.len = token->len - skw.skw_header.len - sht_bytes;
 573         skw.skw_hmac.data = skw.skw_cipher.data + skw.skw_cipher.len;
 574         skw.skw_hmac.len = sht_bytes;
 575
 576         blocksize = crypto_blkcipher_blocksize(skc->sc_session_kb.kb_tfm);
 577         if (skw.skw_cipher.len % blocksize != 0)
 578                 return GSS_S_DEFECTIVE_TOKEN;
 579
 580         skh = (struct sk_hdr *)skw.skw_header.data;
 581         rc = sk_verify_header(skh);
 582         if (rc != GSS_S_COMPLETE)
 583                 return rc;
 584
 585         /* HMAC covers the SK header, GSS header, and ciphertext */
 586         msgbufs[0] = skw.skw_header;
 587         msgbufs[1] = *gss_header;
 588         msgbufs[2] = skw.skw_cipher;
 589         rc = sk_verify_hmac(skc->sc_hmac, &skc->sc_hmac_key, 3, msgbufs,
 590                             0, NULL, &skw.skw_hmac, gss_context->hash_func);
 591         if (rc)
 592                 return rc;
 593
 594         sk_construct_rfc3686_iv(local_iv, skc->sc_peer_random, skh->skh_iv);
 595         message->len = skw.skw_cipher.len;
 596         if (gss_crypt_rawobjs(skc->sc_session_kb.kb_tfm, local_iv,
 597                               1, &skw.skw_cipher, message, 0))
 598                 return GSS_S_FAILURE;
 599
 600         return GSS_S_COMPLETE;
 601 }
 602
 603 static
 604 __u32 gss_prep_bulk_sk(struct gss_ctx *gss_context,
 605                        struct ptlrpc_bulk_desc *desc)
 606 {
 607         struct sk_ctx *skc = gss_context->internal_ctx_id;
 608         int blocksize;
 609         int i;
 610
 611         LASSERT(skc->sc_session_kb.kb_tfm);
 612         blocksize = crypto_blkcipher_blocksize(skc->sc_session_kb.kb_tfm);
 613
 614         for (i = 0; i < desc->bd_iov_count; i++) {
 615                 if (desc->bd_vec[i].kiov_offset & blocksize) {
 616                         CERROR("offset %d not blocksize aligned\n",
 617                                desc->bd_vec[i].kiov_offset);
 618                         return GSS_S_FAILURE;
 619                 }
 620
 621                 desc->bd_enc_vec[i].kiov_offset =
 622                         desc->bd_vec[i].kiov_offset;
 623                 desc->bd_enc_vec[i].kiov_len =
 624                         sk_block_mask(desc->bd_vec[i].kiov_len, blocksize);
 625         }
 626
 627         return GSS_S_COMPLETE;
 628 }
 629
 630 static __u32 sk_encrypt_bulk(struct crypto_blkcipher *tfm, __u8 *iv,
 631                              struct ptlrpc_bulk_desc *desc, rawobj_t *cipher,
 632                              int adj_nob)
 633 {
 634         struct blkcipher_desc cdesc = {
 635                 .tfm = tfm,
 636                 .info = iv,
 637                 .flags = 0,
 638         };
 639         struct scatterlist ptxt;
 640         struct scatterlist ctxt;
 641         int blocksize;
 642         int i;
 643         int rc;
 644         int nob = 0;
 645
 646         blocksize = crypto_blkcipher_blocksize(tfm);
 647
 648         sg_init_table(&ptxt, 1);
 649         sg_init_table(&ctxt, 1);
 650
 651         for (i = 0; i < desc->bd_iov_count; i++) {
 652                 sg_set_page(&ptxt, desc->bd_vec[i].kiov_page,
 653                             sk_block_mask(desc->bd_vec[i].kiov_len,
 654                                           blocksize),
 655                             desc->bd_vec[i].kiov_offset);
 656                 nob += ptxt.length;
 657
 658                 sg_set_page(&ctxt, desc->bd_enc_vec[i].kiov_page,
 659                             ptxt.length, ptxt.offset);
 660
 661                 desc->bd_enc_vec[i].kiov_offset = ctxt.offset;
 662                 desc->bd_enc_vec[i].kiov_len = ctxt.length;
 663
 664                 rc = crypto_blkcipher_encrypt_iv(&cdesc, &ctxt, &ptxt,
 665                                                  ptxt.length);
 666                 if (rc) {
 667                         CERROR("failed to encrypt page: %d\n", rc);
 668                         return rc;
 669                 }
 670         }
 671
 672         if (adj_nob)
 673                 desc->bd_nob = nob;
 674
 675         return 0;
 676 }
 677
 678 static __u32 sk_decrypt_bulk(struct crypto_blkcipher *tfm, __u8 *iv,
 679                              struct ptlrpc_bulk_desc *desc, rawobj_t *cipher,
 680                              int adj_nob)
 681 {
 682         struct blkcipher_desc cdesc = {
 683                 .tfm = tfm,
 684                 .info = iv,
 685                 .flags = 0,
 686         };
 687         struct scatterlist ptxt;
 688         struct scatterlist ctxt;
 689         int blocksize;
 690         int i;
 691         int rc;
 692         int pnob = 0;
 693         int cnob = 0;
 694
 695         sg_init_table(&ptxt, 1);
 696         sg_init_table(&ctxt, 1);
 697
 698         blocksize = crypto_blkcipher_blocksize(tfm);
 699         if (desc->bd_nob_transferred % blocksize != 0) {
 700                 CERROR("Transfer not a multiple of block size: %d\n",
 701                        desc->bd_nob_transferred);
 702                 return GSS_S_DEFECTIVE_TOKEN;
 703         }
 704
 705         for (i = 0; i < desc->bd_iov_count && cnob < desc->bd_nob_transferred;
 706              i++) {
 707                 lnet_kiov_t *piov = &desc->bd_vec[i];
 708                 lnet_kiov_t *ciov = &desc->bd_enc_vec[i];
 709
 710                 if (ciov->kiov_offset % blocksize != 0 ||
 711                     ciov->kiov_len % blocksize != 0) {
 712                         CERROR("Invalid bulk descriptor vector\n");
 713                         return GSS_S_DEFECTIVE_TOKEN;
 714                 }
 715
 716                 /* Must adjust bytes here because we know the actual sizes after
 717                  * decryption.  Similar to what gss_cli_ctx_unwrap_bulk does for
 718                  * integrity only mode */
 719                 if (adj_nob) {
 720                         /* cipher text must not exceed transferred size */
 721                         if (ciov->kiov_len + cnob > desc->bd_nob_transferred)
 722                                 ciov->kiov_len =
 723                                         desc->bd_nob_transferred - cnob;
 724
 725                         piov->kiov_len = ciov->kiov_len;
 726
 727                         /* plain text must not exceed bulk's size */
 728                         if (ciov->kiov_len + pnob > desc->bd_nob)
 729                                 piov->kiov_len = desc->bd_nob - pnob;
 730                 } else {
 731                         /* Taken from krb5_decrypt since it was not verified
 732                          * whether or not LNET guarantees these */
 733                         if (ciov->kiov_len + cnob > desc->bd_nob_transferred ||
 734                             piov->kiov_len > ciov->kiov_len) {
 735                                 CERROR("Invalid decrypted length\n");
 736                                 return GSS_S_FAILURE;
 737                         }
 738                 }
 739
 740                 if (ciov->kiov_len == 0)
 741                         continue;
 742
 743                 sg_init_table(&ctxt, 1);
 744                 sg_set_page(&ctxt, ciov->kiov_page, ciov->kiov_len,
 745                             ciov->kiov_offset);
 746                 ptxt = ctxt;
 747
 748                 /* In the event the plain text size is not a multiple
 749                  * of blocksize we decrypt in place and copy the result
 750                  * after the decryption */
 751                 if (piov->kiov_len % blocksize == 0)
 752                         sg_assign_page(&ptxt, piov->kiov_page);
 753
 754                 rc = crypto_blkcipher_decrypt_iv(&cdesc, &ptxt, &ctxt,
 755                                                  ctxt.length);
 756                 if (rc) {
 757                         CERROR("Decryption failed for page: %d\n", rc);
 758                         return GSS_S_FAILURE;
 759                 }
 760
 761                 if (piov->kiov_len % blocksize != 0) {
 762                         memcpy(page_address(piov->kiov_page) +
 763                                piov->kiov_offset,
 764                                page_address(ciov->kiov_page) +
 765                                ciov->kiov_offset,
 766                                piov->kiov_len);
 767                 }
 768
 769                 cnob += ciov->kiov_len;
 770                 pnob += piov->kiov_len;
 771         }
 772
 773         /* if needed, clear up the rest unused iovs */
 774         if (adj_nob)
 775                 while (i < desc->bd_iov_count)
 776                         desc->bd_vec[i++].kiov_len = 0;
 777
 778         if (unlikely(cnob != desc->bd_nob_transferred)) {
 779                 CERROR("%d cipher text transferred but only %d decrypted\n",
 780                        desc->bd_nob_transferred, cnob);
 781                 return GSS_S_FAILURE;
 782         }
 783
 784         if (unlikely(!adj_nob && pnob != desc->bd_nob)) {
 785                 CERROR("%d plain text expected but only %d received\n",
 786                        desc->bd_nob, pnob);
 787                 return GSS_S_FAILURE;
 788         }
 789
 790         return 0;
 791 }
 792
 793 static
 794 __u32 gss_wrap_bulk_sk(struct gss_ctx *gss_context,
 795                        struct ptlrpc_bulk_desc *desc, rawobj_t *token,
 796                        int adj_nob)
 797 {
 798         struct sk_ctx *skc = gss_context->internal_ctx_id;
 799         size_t sht_bytes = cfs_crypto_hash_digestsize(skc->sc_hmac);
 800         struct sk_wire skw;
 801         struct sk_hdr skh;
 802         __u8 local_iv[SK_IV_SIZE];
 803
 804         LASSERT(skc->sc_session_kb.kb_tfm);
 805
 806         memset(token->data, 0, token->len);
 807         if (sk_fill_header(skc, &skh) != GSS_S_COMPLETE)
 808                 return GSS_S_FAILURE;
 809
 810         skw.skw_header.data = token->data;
 811         skw.skw_header.len = sizeof(skh);
 812         memcpy(skw.skw_header.data, &skh, sizeof(skh));
 813
 814         sk_construct_rfc3686_iv(local_iv, skc->sc_host_random, skh.skh_iv);
 815         skw.skw_cipher.data = skw.skw_header.data + skw.skw_header.len;
 816         skw.skw_cipher.len = token->len - skw.skw_header.len - sht_bytes;
 817         if (sk_encrypt_bulk(skc->sc_session_kb.kb_tfm, local_iv,
 818                             desc, &skw.skw_cipher, adj_nob))
 819                 return GSS_S_FAILURE;
 820
 821         skw.skw_hmac.data = skw.skw_cipher.data + skw.skw_cipher.len;
 822         skw.skw_hmac.len = sht_bytes;
 823         if (sk_make_hmac(skc->sc_hmac, &skc->sc_hmac_key, 1, &skw.skw_cipher,
 824                          desc->bd_iov_count, desc->bd_enc_vec, &skw.skw_hmac,
 825                          gss_context->hash_func))
 826                 return GSS_S_FAILURE;
 827
 828         return GSS_S_COMPLETE;
 829 }
 830
 831 static
 832 __u32 gss_unwrap_bulk_sk(struct gss_ctx *gss_context,
 833                            struct ptlrpc_bulk_desc *desc,
 834                            rawobj_t *token, int adj_nob)
 835 {
 836         struct sk_ctx *skc = gss_context->internal_ctx_id;
 837         size_t sht_bytes = cfs_crypto_hash_digestsize(skc->sc_hmac);
 838         struct sk_wire skw;
 839         struct sk_hdr *skh;
 840         __u8 local_iv[SK_IV_SIZE];
 841         int rc;
 842
 843         LASSERT(skc->sc_session_kb.kb_tfm);
 844
 845         if (token->len < sizeof(skh) + sht_bytes)
 846                 return GSS_S_DEFECTIVE_TOKEN;
 847
 848         skw.skw_header.data = token->data;
 849         skw.skw_header.len = sizeof(struct sk_hdr);
 850         skw.skw_cipher.data = skw.skw_header.data + skw.skw_header.len;
 851         skw.skw_cipher.len = token->len - skw.skw_header.len - sht_bytes;
 852         skw.skw_hmac.data = skw.skw_cipher.data + skw.skw_cipher.len;
 853         skw.skw_hmac.len = sht_bytes;
 854
 855         skh = (struct sk_hdr *)skw.skw_header.data;
 856         rc = sk_verify_header(skh);
 857         if (rc != GSS_S_COMPLETE)
 858                 return rc;
 859
 860         rc = sk_verify_bulk_hmac(skc->sc_hmac, &skc->sc_hmac_key, 1,
 861                                  &skw.skw_cipher, desc->bd_iov_count,
 862                                  desc->bd_enc_vec, desc->bd_nob,
 863                                  &skw.skw_hmac);
 864         if (rc)
 865                 return rc;
 866
 867         sk_construct_rfc3686_iv(local_iv, skc->sc_peer_random, skh->skh_iv);
 868         rc = sk_decrypt_bulk(skc->sc_session_kb.kb_tfm, local_iv,
 869                              desc, &skw.skw_cipher, adj_nob);
 870         if (rc)
 871                 return rc;
 872
 873         return GSS_S_COMPLETE;
 874 }
 875
 876 static
 877 void gss_delete_sec_context_sk(void *internal_context)
 878 {
 879         struct sk_ctx *sk_context = internal_context;
 880         sk_delete_context(sk_context);
 881 }
 882
 883 int gss_display_sk(struct gss_ctx *gss_context, char *buf, int bufsize)
 884 {
 885         return snprintf(buf, bufsize, "sk");
 886 }
 887
 888 static struct gss_api_ops gss_sk_ops = {
 889         .gss_import_sec_context     = gss_import_sec_context_sk,
 890         .gss_copy_reverse_context   = gss_copy_reverse_context_sk,
 891         .gss_inquire_context        = gss_inquire_context_sk,
 892         .gss_get_mic                = gss_get_mic_sk,
 893         .gss_verify_mic             = gss_verify_mic_sk,
 894         .gss_wrap                   = gss_wrap_sk,
 895         .gss_unwrap                 = gss_unwrap_sk,
 896         .gss_prep_bulk              = gss_prep_bulk_sk,
 897         .gss_wrap_bulk              = gss_wrap_bulk_sk,
 898         .gss_unwrap_bulk            = gss_unwrap_bulk_sk,
 899         .gss_delete_sec_context     = gss_delete_sec_context_sk,
 900         .gss_display                = gss_display_sk,
 901 };
 902
 903 static struct subflavor_desc gss_sk_sfs[] = {
 904         {
 905                 .sf_subflavor   = SPTLRPC_SUBFLVR_SKN,
 906                 .sf_qop         = 0,
 907                 .sf_service     = SPTLRPC_SVC_NULL,
 908                 .sf_name        = "skn"
 909         },
 910         {
 911                 .sf_subflavor   = SPTLRPC_SUBFLVR_SKA,
 912                 .sf_qop         = 0,
 913                 .sf_service     = SPTLRPC_SVC_AUTH,
 914                 .sf_name        = "ska"
 915         },
 916         {
 917                 .sf_subflavor   = SPTLRPC_SUBFLVR_SKI,
 918                 .sf_qop         = 0,
 919                 .sf_service     = SPTLRPC_SVC_INTG,
 920                 .sf_name        = "ski"
 921         },
 922         {
 923                 .sf_subflavor   = SPTLRPC_SUBFLVR_SKPI,
 924                 .sf_qop         = 0,
 925                 .sf_service     = SPTLRPC_SVC_PRIV,
 926                 .sf_name        = "skpi"
 927         },
 928 };
 929
 930 static struct gss_api_mech gss_sk_mech = {
 931         /* .gm_owner uses default NULL value for THIS_MODULE */
 932         .gm_name        = "sk",
 933         .gm_oid         = (rawobj_t) {
 934                 .len = 12,
 935                 .data = "\053\006\001\004\001\311\146\215\126\001\000\001",
 936         },
 937         .gm_ops         = &gss_sk_ops,
 938         .gm_sf_num      = 4,
 939         .gm_sfs         = gss_sk_sfs,
 940 };
 941
 942 int __init init_sk_module(void)
 943 {
 944         int status;
 945
 946         status = lgss_mech_register(&gss_sk_mech);
 947         if (status)
 948                 CERROR("Failed to register sk gss mechanism!\n");
 949
 950         return status;
 951 }
 952
 953 void cleanup_sk_module(void)
 954 {
 955         lgss_mech_unregister(&gss_sk_mech);
 956 }