lustre/ptlrpc/gss/gss_krb5_mech.c

   1 /*
   2  * Modifications for Lustre
   3  *
   4  * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
   5  *
   6  * Copyright (c) 2011, 2015, Intel Corporation.
   7  *
   8  * Author: Eric Mei <ericm@clusterfs.com>
   9  */
  10
  11 /*
  12  *  linux/net/sunrpc/gss_krb5_mech.c
  13  *  linux/net/sunrpc/gss_krb5_crypto.c
  14  *  linux/net/sunrpc/gss_krb5_seal.c
  15  *  linux/net/sunrpc/gss_krb5_seqnum.c
  16  *  linux/net/sunrpc/gss_krb5_unseal.c
  17  *
  18  *  Copyright (c) 2001 The Regents of the University of Michigan.
  19  *  All rights reserved.
  20  *
  21  *  Andy Adamson <andros@umich.edu>
  22  *  J. Bruce Fields <bfields@umich.edu>
  23  *
  24  *  Redistribution and use in source and binary forms, with or without
  25  *  modification, are permitted provided that the following conditions
  26  *  are met:
  27  *
  28  *  1. Redistributions of source code must retain the above copyright
  29  *     notice, this list of conditions and the following disclaimer.
  30  *  2. Redistributions in binary form must reproduce the above copyright
  31  *     notice, this list of conditions and the following disclaimer in the
  32  *     documentation and/or other materials provided with the distribution.
  33  *  3. Neither the name of the University nor the names of its
  34  *     contributors may be used to endorse or promote products derived
  35  *     from this software without specific prior written permission.
  36  *
  37  *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
  38  *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  39  *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  40  *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  41  *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  42  *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  43  *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
  44  *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  45  *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  46  *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  47  *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  48  *
  49  */
  50
  51 #define DEBUG_SUBSYSTEM S_SEC
  52 #include <linux/init.h>
  53 #include <linux/module.h>
  54 #include <linux/slab.h>
  55 #include <linux/crypto.h>
  56 #include <linux/mutex.h>
  57
  58 #include <obd.h>
  59 #include <obd_class.h>
  60 #include <obd_support.h>
  61 #include <lustre/lustre_idl.h>
  62 #include <lustre_net.h>
  63 #include <lustre_import.h>
  64 #include <lustre_sec.h>
  65
  66 #include "gss_err.h"
  67 #include "gss_internal.h"
  68 #include "gss_api.h"
  69 #include "gss_asn1.h"
  70 #include "gss_krb5.h"
  71
  72 static spinlock_t krb5_seq_lock;
  73
  74 struct krb5_enctype {
  75         char           *ke_dispname;
  76         char           *ke_enc_name;            /* linux tfm name */
  77         char           *ke_hash_name;           /* linux tfm name */
  78         int             ke_enc_mode;            /* linux tfm mode */
  79         int             ke_hash_size;           /* checksum size */
  80         int             ke_conf_size;           /* confounder size */
  81         unsigned int    ke_hash_hmac:1;         /* is hmac? */
  82 };
  83
  84 /*
  85  * NOTE: for aes128-cts and aes256-cts, MIT implementation use CTS encryption.
  86  * but currently we simply CBC with padding, because linux doesn't support CTS
  87  * yet. this need to be fixed in the future.
  88  */
  89 static struct krb5_enctype enctypes[] = {
  90         [ENCTYPE_DES_CBC_RAW] = {               /* des-cbc-md5 */
  91                 "des-cbc-md5",
  92                 "cbc(des)",
  93                 "md5",
  94                 0,
  95                 16,
  96                 8,
  97                 0,
  98         },
  99         [ENCTYPE_DES3_CBC_RAW] = {              /* des3-hmac-sha1 */
 100                 "des3-hmac-sha1",
 101                 "cbc(des3_ede)",
 102                 "hmac(sha1)",
 103                 0,
 104                 20,
 105                 8,
 106                 1,
 107         },
 108         [ENCTYPE_AES128_CTS_HMAC_SHA1_96] = {   /* aes128-cts */
 109                 "aes128-cts-hmac-sha1-96",
 110                 "cbc(aes)",
 111                 "hmac(sha1)",
 112                 0,
 113                 12,
 114                 16,
 115                 1,
 116         },
 117         [ENCTYPE_AES256_CTS_HMAC_SHA1_96] = {   /* aes256-cts */
 118                 "aes256-cts-hmac-sha1-96",
 119                 "cbc(aes)",
 120                 "hmac(sha1)",
 121                 0,
 122                 12,
 123                 16,
 124                 1,
 125         },
 126         [ENCTYPE_ARCFOUR_HMAC] = {              /* arcfour-hmac-md5 */
 127                 "arcfour-hmac-md5",
 128                 "ecb(arc4)",
 129                 "hmac(md5)",
 130                 0,
 131                 16,
 132                 8,
 133                 1,
 134         },
 135 };
 136
 137 #define MAX_ENCTYPES    sizeof(enctypes)/sizeof(struct krb5_enctype)
 138
 139 static const char * enctype2str(__u32 enctype)
 140 {
 141         if (enctype < MAX_ENCTYPES && enctypes[enctype].ke_dispname)
 142                 return enctypes[enctype].ke_dispname;
 143
 144         return "unknown";
 145 }
 146
 147 static
 148 int keyblock_init(struct krb5_keyblock *kb, char *alg_name, int alg_mode)
 149 {
 150         kb->kb_tfm = crypto_alloc_blkcipher(alg_name, alg_mode, 0);
 151         if (IS_ERR(kb->kb_tfm)) {
 152                 CERROR("failed to alloc tfm: %s, mode %d\n",
 153                        alg_name, alg_mode);
 154                 return -1;
 155         }
 156
 157         if (crypto_blkcipher_setkey(kb->kb_tfm, kb->kb_key.data, kb->kb_key.len)) {
 158                 CERROR("failed to set %s key, len %d\n",
 159                        alg_name, kb->kb_key.len);
 160                 return -1;
 161         }
 162
 163         return 0;
 164 }
 165
 166 static
 167 int krb5_init_keys(struct krb5_ctx *kctx)
 168 {
 169         struct krb5_enctype *ke;
 170
 171         if (kctx->kc_enctype >= MAX_ENCTYPES ||
 172             enctypes[kctx->kc_enctype].ke_hash_size == 0) {
 173                 CERROR("unsupported enctype %x\n", kctx->kc_enctype);
 174                 return -1;
 175         }
 176
 177         ke = &enctypes[kctx->kc_enctype];
 178
 179         /* tfm arc4 is stateful, user should alloc-use-free by his own */
 180         if (kctx->kc_enctype != ENCTYPE_ARCFOUR_HMAC &&
 181             keyblock_init(&kctx->kc_keye, ke->ke_enc_name, ke->ke_enc_mode))
 182                 return -1;
 183
 184         /* tfm hmac is stateful, user should alloc-use-free by his own */
 185         if (ke->ke_hash_hmac == 0 &&
 186             keyblock_init(&kctx->kc_keyi, ke->ke_enc_name, ke->ke_enc_mode))
 187                 return -1;
 188         if (ke->ke_hash_hmac == 0 &&
 189             keyblock_init(&kctx->kc_keyc, ke->ke_enc_name, ke->ke_enc_mode))
 190                 return -1;
 191
 192         return 0;
 193 }
 194
 195 static
 196 void keyblock_free(struct krb5_keyblock *kb)
 197 {
 198         rawobj_free(&kb->kb_key);
 199         if (kb->kb_tfm)
 200                 crypto_free_blkcipher(kb->kb_tfm);
 201 }
 202
 203 static
 204 int keyblock_dup(struct krb5_keyblock *new, struct krb5_keyblock *kb)
 205 {
 206         return rawobj_dup(&new->kb_key, &kb->kb_key);
 207 }
 208
 209 static
 210 int get_bytes(char **ptr, const char *end, void *res, int len)
 211 {
 212         char *p, *q;
 213         p = *ptr;
 214         q = p + len;
 215         if (q > end || q < p)
 216                 return -1;
 217         memcpy(res, p, len);
 218         *ptr = q;
 219         return 0;
 220 }
 221
 222 static
 223 int get_rawobj(char **ptr, const char *end, rawobj_t *res)
 224 {
 225         char   *p, *q;
 226         __u32   len;
 227
 228         p = *ptr;
 229         if (get_bytes(&p, end, &len, sizeof(len)))
 230                 return -1;
 231
 232         q = p + len;
 233         if (q > end || q < p)
 234                 return -1;
 235
 236         OBD_ALLOC_LARGE(res->data, len);
 237         if (!res->data)
 238                 return -1;
 239
 240         res->len = len;
 241         memcpy(res->data, p, len);
 242         *ptr = q;
 243         return 0;
 244 }
 245
 246 static
 247 int get_keyblock(char **ptr, const char *end,
 248                  struct krb5_keyblock *kb, __u32 keysize)
 249 {
 250         char *buf;
 251
 252         OBD_ALLOC_LARGE(buf, keysize);
 253         if (buf == NULL)
 254                 return -1;
 255
 256         if (get_bytes(ptr, end, buf, keysize)) {
 257                 OBD_FREE_LARGE(buf, keysize);
 258                 return -1;
 259         }
 260
 261         kb->kb_key.len = keysize;
 262         kb->kb_key.data = buf;
 263         return 0;
 264 }
 265
 266 static
 267 void delete_context_kerberos(struct krb5_ctx *kctx)
 268 {
 269         rawobj_free(&kctx->kc_mech_used);
 270
 271         keyblock_free(&kctx->kc_keye);
 272         keyblock_free(&kctx->kc_keyi);
 273         keyblock_free(&kctx->kc_keyc);
 274 }
 275
 276 static
 277 __u32 import_context_rfc1964(struct krb5_ctx *kctx, char *p, char *end)
 278 {
 279         unsigned int    tmp_uint, keysize;
 280
 281         /* seed_init flag */
 282         if (get_bytes(&p, end, &tmp_uint, sizeof(tmp_uint)))
 283                 goto out_err;
 284         kctx->kc_seed_init = (tmp_uint != 0);
 285
 286         /* seed */
 287         if (get_bytes(&p, end, kctx->kc_seed, sizeof(kctx->kc_seed)))
 288                 goto out_err;
 289
 290         /* sign/seal algorithm, not really used now */
 291         if (get_bytes(&p, end, &tmp_uint, sizeof(tmp_uint)) ||
 292             get_bytes(&p, end, &tmp_uint, sizeof(tmp_uint)))
 293                 goto out_err;
 294
 295         /* end time */
 296         if (get_bytes(&p, end, &kctx->kc_endtime, sizeof(kctx->kc_endtime)))
 297                 goto out_err;
 298
 299         /* seq send */
 300         if (get_bytes(&p, end, &tmp_uint, sizeof(tmp_uint)))
 301                 goto out_err;
 302         kctx->kc_seq_send = tmp_uint;
 303
 304         /* mech oid */
 305         if (get_rawobj(&p, end, &kctx->kc_mech_used))
 306                 goto out_err;
 307
 308         /* old style enc/seq keys in format:
 309          *   - enctype (u32)
 310          *   - keysize (u32)
 311          *   - keydata
 312          * we decompose them to fit into the new context
 313          */
 314
 315         /* enc key */
 316         if (get_bytes(&p, end, &kctx->kc_enctype, sizeof(kctx->kc_enctype)))
 317                 goto out_err;
 318
 319         if (get_bytes(&p, end, &keysize, sizeof(keysize)))
 320                 goto out_err;
 321
 322         if (get_keyblock(&p, end, &kctx->kc_keye, keysize))
 323                 goto out_err;
 324
 325         /* seq key */
 326         if (get_bytes(&p, end, &tmp_uint, sizeof(tmp_uint)) ||
 327             tmp_uint != kctx->kc_enctype)
 328                 goto out_err;
 329
 330         if (get_bytes(&p, end, &tmp_uint, sizeof(tmp_uint)) ||
 331             tmp_uint != keysize)
 332                 goto out_err;
 333
 334         if (get_keyblock(&p, end, &kctx->kc_keyc, keysize))
 335                 goto out_err;
 336
 337         /* old style fallback */
 338         if (keyblock_dup(&kctx->kc_keyi, &kctx->kc_keyc))
 339                 goto out_err;
 340
 341         if (p != end)
 342                 goto out_err;
 343
 344         CDEBUG(D_SEC, "successfully imported rfc1964 context\n");
 345         return 0;
 346 out_err:
 347         return GSS_S_FAILURE;
 348 }
 349
 350 /* Flags for version 2 context flags */
 351 #define KRB5_CTX_FLAG_INITIATOR         0x00000001
 352 #define KRB5_CTX_FLAG_CFX               0x00000002
 353 #define KRB5_CTX_FLAG_ACCEPTOR_SUBKEY   0x00000004
 354
 355 static
 356 __u32 import_context_rfc4121(struct krb5_ctx *kctx, char *p, char *end)
 357 {
 358         unsigned int    tmp_uint, keysize;
 359
 360         /* end time */
 361         if (get_bytes(&p, end, &kctx->kc_endtime, sizeof(kctx->kc_endtime)))
 362                 goto out_err;
 363
 364         /* flags */
 365         if (get_bytes(&p, end, &tmp_uint, sizeof(tmp_uint)))
 366                 goto out_err;
 367
 368         if (tmp_uint & KRB5_CTX_FLAG_INITIATOR)
 369                 kctx->kc_initiate = 1;
 370         if (tmp_uint & KRB5_CTX_FLAG_CFX)
 371                 kctx->kc_cfx = 1;
 372         if (tmp_uint & KRB5_CTX_FLAG_ACCEPTOR_SUBKEY)
 373                 kctx->kc_have_acceptor_subkey = 1;
 374
 375         /* seq send */
 376         if (get_bytes(&p, end, &kctx->kc_seq_send, sizeof(kctx->kc_seq_send)))
 377                 goto out_err;
 378
 379         /* enctype */
 380         if (get_bytes(&p, end, &kctx->kc_enctype, sizeof(kctx->kc_enctype)))
 381                 goto out_err;
 382
 383         /* size of each key */
 384         if (get_bytes(&p, end, &keysize, sizeof(keysize)))
 385                 goto out_err;
 386
 387         /* number of keys - should always be 3 */
 388         if (get_bytes(&p, end, &tmp_uint, sizeof(tmp_uint)))
 389                 goto out_err;
 390
 391         if (tmp_uint != 3) {
 392                 CERROR("Invalid number of keys: %u\n", tmp_uint);
 393                 goto out_err;
 394         }
 395
 396         /* ke */
 397         if (get_keyblock(&p, end, &kctx->kc_keye, keysize))
 398                 goto out_err;
 399         /* ki */
 400         if (get_keyblock(&p, end, &kctx->kc_keyi, keysize))
 401                 goto out_err;
 402         /* ki */
 403         if (get_keyblock(&p, end, &kctx->kc_keyc, keysize))
 404                 goto out_err;
 405
 406         CDEBUG(D_SEC, "successfully imported v2 context\n");
 407         return 0;
 408 out_err:
 409         return GSS_S_FAILURE;
 410 }
 411
 412 /*
 413  * The whole purpose here is trying to keep user level gss context parsing
 414  * from nfs-utils unchanged as possible as we can, they are not quite mature
 415  * yet, and many stuff still not clear, like heimdal etc.
 416  */
 417 static
 418 __u32 gss_import_sec_context_kerberos(rawobj_t *inbuf,
 419                                       struct gss_ctx *gctx)
 420 {
 421         struct krb5_ctx *kctx;
 422         char            *p = (char *) inbuf->data;
 423         char            *end = (char *) (inbuf->data + inbuf->len);
 424         unsigned int     tmp_uint, rc;
 425
 426         if (get_bytes(&p, end, &tmp_uint, sizeof(tmp_uint))) {
 427                 CERROR("Fail to read version\n");
 428                 return GSS_S_FAILURE;
 429         }
 430
 431         /* only support 0, 1 for the moment */
 432         if (tmp_uint > 2) {
 433                 CERROR("Invalid version %u\n", tmp_uint);
 434                 return GSS_S_FAILURE;
 435         }
 436
 437         OBD_ALLOC_PTR(kctx);
 438         if (!kctx)
 439                 return GSS_S_FAILURE;
 440
 441         if (tmp_uint == 0 || tmp_uint == 1) {
 442                 kctx->kc_initiate = tmp_uint;
 443                 rc = import_context_rfc1964(kctx, p, end);
 444         } else {
 445                 rc = import_context_rfc4121(kctx, p, end);
 446         }
 447
 448         if (rc == 0)
 449                 rc = krb5_init_keys(kctx);
 450
 451         if (rc) {
 452                 delete_context_kerberos(kctx);
 453                 OBD_FREE_PTR(kctx);
 454
 455                 return GSS_S_FAILURE;
 456         }
 457
 458         gctx->internal_ctx_id = kctx;
 459         return GSS_S_COMPLETE;
 460 }
 461
 462 static
 463 __u32 gss_copy_reverse_context_kerberos(struct gss_ctx *gctx,
 464                                         struct gss_ctx *gctx_new)
 465 {
 466         struct krb5_ctx *kctx = gctx->internal_ctx_id;
 467         struct krb5_ctx *knew;
 468
 469         OBD_ALLOC_PTR(knew);
 470         if (!knew)
 471                 return GSS_S_FAILURE;
 472
 473         knew->kc_initiate = kctx->kc_initiate ? 0 : 1;
 474         knew->kc_cfx = kctx->kc_cfx;
 475         knew->kc_seed_init = kctx->kc_seed_init;
 476         knew->kc_have_acceptor_subkey = kctx->kc_have_acceptor_subkey;
 477         knew->kc_endtime = kctx->kc_endtime;
 478
 479         memcpy(knew->kc_seed, kctx->kc_seed, sizeof(kctx->kc_seed));
 480         knew->kc_seq_send = kctx->kc_seq_recv;
 481         knew->kc_seq_recv = kctx->kc_seq_send;
 482         knew->kc_enctype = kctx->kc_enctype;
 483
 484         if (rawobj_dup(&knew->kc_mech_used, &kctx->kc_mech_used))
 485                 goto out_err;
 486
 487         if (keyblock_dup(&knew->kc_keye, &kctx->kc_keye))
 488                 goto out_err;
 489         if (keyblock_dup(&knew->kc_keyi, &kctx->kc_keyi))
 490                 goto out_err;
 491         if (keyblock_dup(&knew->kc_keyc, &kctx->kc_keyc))
 492                 goto out_err;
 493         if (krb5_init_keys(knew))
 494                 goto out_err;
 495
 496         gctx_new->internal_ctx_id = knew;
 497         CDEBUG(D_SEC, "successfully copied reverse context\n");
 498         return GSS_S_COMPLETE;
 499
 500 out_err:
 501         delete_context_kerberos(knew);
 502         OBD_FREE_PTR(knew);
 503         return GSS_S_FAILURE;
 504 }
 505
 506 static
 507 __u32 gss_inquire_context_kerberos(struct gss_ctx *gctx,
 508                                    unsigned long  *endtime)
 509 {
 510         struct krb5_ctx *kctx = gctx->internal_ctx_id;
 511
 512         *endtime = (unsigned long) ((__u32) kctx->kc_endtime);
 513         return GSS_S_COMPLETE;
 514 }
 515
 516 static
 517 void gss_delete_sec_context_kerberos(void *internal_ctx)
 518 {
 519         struct krb5_ctx *kctx = internal_ctx;
 520
 521         delete_context_kerberos(kctx);
 522         OBD_FREE_PTR(kctx);
 523 }
 524
 525 /*
 526  * Should be used for buffers allocated with k/vmalloc().
 527  *
 528  * Dispose of @sgt with teardown_sgtable().
 529  *
 530  * @prealloc_sg is to avoid memory allocation inside sg_alloc_table()
 531  * in cases where a single sg is sufficient.  No attempt to reduce the
 532  * number of sgs by squeezing physically contiguous pages together is
 533  * made though, for simplicity.
 534  *
 535  * This function is copied from the ceph filesystem code.
 536  */
 537 static int setup_sgtable(struct sg_table *sgt, struct scatterlist *prealloc_sg,
 538                          const void *buf, unsigned int buf_len)
 539 {
 540         struct scatterlist *sg;
 541         const bool is_vmalloc = is_vmalloc_addr(buf);
 542         unsigned int off = offset_in_page(buf);
 543         unsigned int chunk_cnt = 1;
 544         unsigned int chunk_len = PAGE_ALIGN(off + buf_len);
 545         int i;
 546         int ret;
 547
 548         if (buf_len == 0) {
 549                 memset(sgt, 0, sizeof(*sgt));
 550                 return -EINVAL;
 551         }
 552
 553         if (is_vmalloc) {
 554                 chunk_cnt = chunk_len >> PAGE_SHIFT;
 555                 chunk_len = PAGE_SIZE;
 556         }
 557
 558         if (chunk_cnt > 1) {
 559                 ret = sg_alloc_table(sgt, chunk_cnt, GFP_NOFS);
 560                 if (ret)
 561                         return ret;
 562         } else {
 563                 WARN_ON(chunk_cnt != 1);
 564                 sg_init_table(prealloc_sg, 1);
 565                 sgt->sgl = prealloc_sg;
 566                 sgt->nents = sgt->orig_nents = 1;
 567         }
 568
 569         for_each_sg(sgt->sgl, sg, sgt->orig_nents, i) {
 570                 struct page *page;
 571                 unsigned int len = min(chunk_len - off, buf_len);
 572
 573                 if (is_vmalloc)
 574                         page = vmalloc_to_page(buf);
 575                 else
 576                         page = virt_to_page(buf);
 577
 578                 sg_set_page(sg, page, len, off);
 579
 580                 off = 0;
 581                 buf += len;
 582                 buf_len -= len;
 583         }
 584
 585         WARN_ON(buf_len != 0);
 586
 587         return 0;
 588 }
 589
 590 static void teardown_sgtable(struct sg_table *sgt)
 591 {
 592         if (sgt->orig_nents > 1)
 593                 sg_free_table(sgt);
 594 }
 595
 596 static
 597 __u32 krb5_encrypt(struct crypto_blkcipher *tfm,
 598                    int decrypt,
 599                    void * iv,
 600                    void * in,
 601                    void * out,
 602                    int length)
 603 {
 604         struct sg_table sg_out;
 605         struct blkcipher_desc desc;
 606         struct scatterlist    sg;
 607         __u8 local_iv[16] = {0};
 608         __u32 ret = -EINVAL;
 609
 610         LASSERT(tfm);
 611         desc.tfm  = tfm;
 612         desc.info = local_iv;
 613         desc.flags= 0;
 614
 615         if (length % crypto_blkcipher_blocksize(tfm) != 0) {
 616                 CERROR("output length %d mismatch blocksize %d\n",
 617                        length, crypto_blkcipher_blocksize(tfm));
 618                 goto out;
 619         }
 620
 621         if (crypto_blkcipher_ivsize(tfm) > 16) {
 622                 CERROR("iv size too large %d\n", crypto_blkcipher_ivsize(tfm));
 623                 goto out;
 624         }
 625
 626         if (iv)
 627                 memcpy(local_iv, iv, crypto_blkcipher_ivsize(tfm));
 628
 629         memcpy(out, in, length);
 630
 631         ret = setup_sgtable(&sg_out, &sg, out, length);
 632         if (ret != 0)
 633                 goto out;
 634
 635         if (decrypt)
 636                 ret = crypto_blkcipher_decrypt_iv(&desc, sg_out.sgl,
 637                                                   sg_out.sgl, length);
 638         else
 639                 ret = crypto_blkcipher_encrypt_iv(&desc, sg_out.sgl,
 640                                                   sg_out.sgl, length);
 641
 642         teardown_sgtable(&sg_out);
 643 out:
 644         return ret;
 645 }
 646
 647 static inline
 648 int krb5_digest_hmac(struct crypto_hash *tfm,
 649                      rawobj_t *key,
 650                      struct krb5_header *khdr,
 651                      int msgcnt, rawobj_t *msgs,
 652                      int iovcnt, lnet_kiov_t *iovs,
 653                      rawobj_t *cksum)
 654 {
 655         struct hash_desc        desc;
 656         struct sg_table         sgt;
 657         struct scatterlist      sg[1];
 658         int                     i, rc;
 659
 660         crypto_hash_setkey(tfm, key->data, key->len);
 661         desc.tfm  = tfm;
 662         desc.flags= 0;
 663
 664         crypto_hash_init(&desc);
 665
 666         for (i = 0; i < msgcnt; i++) {
 667                 if (msgs[i].len == 0)
 668                         continue;
 669
 670                 rc = setup_sgtable(&sgt, sg, msgs[i].data, msgs[i].len);
 671                 if (rc != 0)
 672                         return rc;
 673
 674                 crypto_hash_update(&desc, sgt.sgl, msgs[i].len);
 675
 676                 teardown_sgtable(&sgt);
 677         }
 678
 679         for (i = 0; i < iovcnt; i++) {
 680                 if (iovs[i].kiov_len == 0)
 681                         continue;
 682
 683                 sg_init_table(sg, 1);
 684                 sg_set_page(&sg[0], iovs[i].kiov_page, iovs[i].kiov_len,
 685                             iovs[i].kiov_offset);
 686                 crypto_hash_update(&desc, sg, iovs[i].kiov_len);
 687         }
 688
 689         if (khdr) {
 690                 rc = setup_sgtable(&sgt, sg, (char *) khdr, sizeof(*khdr));
 691                 if (rc != 0)
 692                         return rc;
 693
 694                 crypto_hash_update(&desc, sgt.sgl, sizeof(*khdr));
 695
 696                 teardown_sgtable(&sgt);
 697         }
 698
 699         return crypto_hash_final(&desc, cksum->data);
 700 }
 701
 702 static inline
 703 int krb5_digest_norm(struct crypto_hash *tfm,
 704                      struct krb5_keyblock *kb,
 705                      struct krb5_header *khdr,
 706                      int msgcnt, rawobj_t *msgs,
 707                      int iovcnt, lnet_kiov_t *iovs,
 708                      rawobj_t *cksum)
 709 {
 710         struct hash_desc        desc;
 711         struct scatterlist      sg[1];
 712         struct sg_table         sgt;
 713         int                     i, rc;
 714
 715         LASSERT(kb->kb_tfm);
 716         desc.tfm  = tfm;
 717         desc.flags= 0;
 718
 719         crypto_hash_init(&desc);
 720
 721         for (i = 0; i < msgcnt; i++) {
 722                 if (msgs[i].len == 0)
 723                         continue;
 724
 725                 rc = setup_sgtable(&sgt, sg, msgs[i].data, msgs[i].len);
 726                 if (rc != 0)
 727                         return rc;
 728
 729                 crypto_hash_update(&desc, sgt.sgl, msgs[i].len);
 730
 731                 teardown_sgtable(&sgt);
 732         }
 733
 734         for (i = 0; i < iovcnt; i++) {
 735                 if (iovs[i].kiov_len == 0)
 736                         continue;
 737
 738                 sg_init_table(sg, 1);
 739                 sg_set_page(&sg[0], iovs[i].kiov_page, iovs[i].kiov_len,
 740                             iovs[i].kiov_offset);
 741                 crypto_hash_update(&desc, sg, iovs[i].kiov_len);
 742         }
 743
 744         if (khdr) {
 745                 rc = setup_sgtable(&sgt, sg, (char *) khdr, sizeof(*khdr));
 746                 if (rc != 0)
 747                         return rc;
 748
 749                 crypto_hash_update(&desc, sgt.sgl, sizeof(*khdr));
 750
 751                 teardown_sgtable(&sgt);
 752         }
 753
 754         crypto_hash_final(&desc, cksum->data);
 755
 756         return krb5_encrypt(kb->kb_tfm, 0, NULL, cksum->data,
 757                             cksum->data, cksum->len);
 758 }
 759
 760 /*
 761  * compute (keyed/keyless) checksum against the plain text which appended
 762  * with krb5 wire token header.
 763  */
 764 static
 765 __s32 krb5_make_checksum(__u32 enctype,
 766                          struct krb5_keyblock *kb,
 767                          struct krb5_header *khdr,
 768                          int msgcnt, rawobj_t *msgs,
 769                          int iovcnt, lnet_kiov_t *iovs,
 770                          rawobj_t *cksum)
 771 {
 772         struct krb5_enctype   *ke = &enctypes[enctype];
 773         struct crypto_hash    *tfm;
 774         __u32                  code = GSS_S_FAILURE;
 775         int                    rc;
 776
 777         if (!(tfm = crypto_alloc_hash(ke->ke_hash_name, 0, 0))) {
 778                 CERROR("failed to alloc TFM: %s\n", ke->ke_hash_name);
 779                 return GSS_S_FAILURE;
 780         }
 781
 782         cksum->len = crypto_hash_digestsize(tfm);
 783         OBD_ALLOC_LARGE(cksum->data, cksum->len);
 784         if (!cksum->data) {
 785                 cksum->len = 0;
 786                 goto out_tfm;
 787         }
 788
 789         if (ke->ke_hash_hmac)
 790                 rc = krb5_digest_hmac(tfm, &kb->kb_key,
 791                                       khdr, msgcnt, msgs, iovcnt, iovs, cksum);
 792         else
 793                 rc = krb5_digest_norm(tfm, kb,
 794                                       khdr, msgcnt, msgs, iovcnt, iovs, cksum);
 795
 796         if (rc == 0)
 797                 code = GSS_S_COMPLETE;
 798 out_tfm:
 799         crypto_free_hash(tfm);
 800         return code;
 801 }
 802
 803 static void fill_krb5_header(struct krb5_ctx *kctx,
 804                              struct krb5_header *khdr,
 805                              int privacy)
 806 {
 807         unsigned char acceptor_flag;
 808
 809         acceptor_flag = kctx->kc_initiate ? 0 : FLAG_SENDER_IS_ACCEPTOR;
 810
 811         if (privacy) {
 812                 khdr->kh_tok_id = cpu_to_be16(KG_TOK_WRAP_MSG);
 813                 khdr->kh_flags = acceptor_flag | FLAG_WRAP_CONFIDENTIAL;
 814                 khdr->kh_ec = cpu_to_be16(0);
 815                 khdr->kh_rrc = cpu_to_be16(0);
 816         } else {
 817                 khdr->kh_tok_id = cpu_to_be16(KG_TOK_MIC_MSG);
 818                 khdr->kh_flags = acceptor_flag;
 819                 khdr->kh_ec = cpu_to_be16(0xffff);
 820                 khdr->kh_rrc = cpu_to_be16(0xffff);
 821         }
 822
 823         khdr->kh_filler = 0xff;
 824         spin_lock(&krb5_seq_lock);
 825         khdr->kh_seq = cpu_to_be64(kctx->kc_seq_send++);
 826         spin_unlock(&krb5_seq_lock);
 827 }
 828
 829 static __u32 verify_krb5_header(struct krb5_ctx *kctx,
 830                                 struct krb5_header *khdr,
 831                                 int privacy)
 832 {
 833         unsigned char acceptor_flag;
 834         __u16         tok_id, ec_rrc;
 835
 836         acceptor_flag = kctx->kc_initiate ? FLAG_SENDER_IS_ACCEPTOR : 0;
 837
 838         if (privacy) {
 839                 tok_id = KG_TOK_WRAP_MSG;
 840                 ec_rrc = 0x0;
 841         } else {
 842                 tok_id = KG_TOK_MIC_MSG;
 843                 ec_rrc = 0xffff;
 844         }
 845
 846         /* sanity checks */
 847         if (be16_to_cpu(khdr->kh_tok_id) != tok_id) {
 848                 CERROR("bad token id\n");
 849                 return GSS_S_DEFECTIVE_TOKEN;
 850         }
 851         if ((khdr->kh_flags & FLAG_SENDER_IS_ACCEPTOR) != acceptor_flag) {
 852                 CERROR("bad direction flag\n");
 853                 return GSS_S_BAD_SIG;
 854         }
 855         if (privacy && (khdr->kh_flags & FLAG_WRAP_CONFIDENTIAL) == 0) {
 856                 CERROR("missing confidential flag\n");
 857                 return GSS_S_BAD_SIG;
 858         }
 859         if (khdr->kh_filler != 0xff) {
 860                 CERROR("bad filler\n");
 861                 return GSS_S_DEFECTIVE_TOKEN;
 862         }
 863         if (be16_to_cpu(khdr->kh_ec) != ec_rrc ||
 864             be16_to_cpu(khdr->kh_rrc) != ec_rrc) {
 865                 CERROR("bad EC or RRC\n");
 866                 return GSS_S_DEFECTIVE_TOKEN;
 867         }
 868         return GSS_S_COMPLETE;
 869 }
 870
 871 static
 872 __u32 gss_get_mic_kerberos(struct gss_ctx *gctx,
 873                            int msgcnt,
 874                            rawobj_t *msgs,
 875                            int iovcnt,
 876                            lnet_kiov_t *iovs,
 877                            rawobj_t *token)
 878 {
 879         struct krb5_ctx     *kctx = gctx->internal_ctx_id;
 880         struct krb5_enctype *ke = &enctypes[kctx->kc_enctype];
 881         struct krb5_header  *khdr;
 882         rawobj_t             cksum = RAWOBJ_EMPTY;
 883
 884         /* fill krb5 header */
 885         LASSERT(token->len >= sizeof(*khdr));
 886         khdr = (struct krb5_header *) token->data;
 887         fill_krb5_header(kctx, khdr, 0);
 888
 889         /* checksum */
 890         if (krb5_make_checksum(kctx->kc_enctype, &kctx->kc_keyc,
 891                                khdr, msgcnt, msgs, iovcnt, iovs, &cksum))
 892                 return GSS_S_FAILURE;
 893
 894         LASSERT(cksum.len >= ke->ke_hash_size);
 895         LASSERT(token->len >= sizeof(*khdr) + ke->ke_hash_size);
 896         memcpy(khdr + 1, cksum.data + cksum.len - ke->ke_hash_size,
 897                ke->ke_hash_size);
 898
 899         token->len = sizeof(*khdr) + ke->ke_hash_size;
 900         rawobj_free(&cksum);
 901         return GSS_S_COMPLETE;
 902 }
 903
 904 static
 905 __u32 gss_verify_mic_kerberos(struct gss_ctx *gctx,
 906                               int msgcnt,
 907                               rawobj_t *msgs,
 908                               int iovcnt,
 909                               lnet_kiov_t *iovs,
 910                               rawobj_t *token)
 911 {
 912         struct krb5_ctx     *kctx = gctx->internal_ctx_id;
 913         struct krb5_enctype *ke = &enctypes[kctx->kc_enctype];
 914         struct krb5_header  *khdr;
 915         rawobj_t             cksum = RAWOBJ_EMPTY;
 916         __u32                major;
 917
 918         if (token->len < sizeof(*khdr)) {
 919                 CERROR("short signature: %u\n", token->len);
 920                 return GSS_S_DEFECTIVE_TOKEN;
 921         }
 922
 923         khdr = (struct krb5_header *) token->data;
 924
 925         major = verify_krb5_header(kctx, khdr, 0);
 926         if (major != GSS_S_COMPLETE) {
 927                 CERROR("bad krb5 header\n");
 928                 return major;
 929         }
 930
 931         if (token->len < sizeof(*khdr) + ke->ke_hash_size) {
 932                 CERROR("short signature: %u, require %d\n",
 933                        token->len, (int) sizeof(*khdr) + ke->ke_hash_size);
 934                 return GSS_S_FAILURE;
 935         }
 936
 937         if (krb5_make_checksum(kctx->kc_enctype, &kctx->kc_keyc,
 938                                khdr, msgcnt, msgs, iovcnt, iovs, &cksum)) {
 939                 CERROR("failed to make checksum\n");
 940                 return GSS_S_FAILURE;
 941         }
 942
 943         LASSERT(cksum.len >= ke->ke_hash_size);
 944         if (memcmp(khdr + 1, cksum.data + cksum.len - ke->ke_hash_size,
 945                    ke->ke_hash_size)) {
 946                 CERROR("checksum mismatch\n");
 947                 rawobj_free(&cksum);
 948                 return GSS_S_BAD_SIG;
 949         }
 950
 951         rawobj_free(&cksum);
 952         return GSS_S_COMPLETE;
 953 }
 954
 955 static
 956 int add_padding(rawobj_t *msg, int msg_buflen, int blocksize)
 957 {
 958         int padding;
 959
 960         padding = (blocksize - (msg->len & (blocksize - 1))) &
 961                   (blocksize - 1);
 962         if (!padding)
 963                 return 0;
 964
 965         if (msg->len + padding > msg_buflen) {
 966                 CERROR("bufsize %u too small: datalen %u, padding %u\n",
 967                         msg_buflen, msg->len, padding);
 968                 return -EINVAL;
 969         }
 970
 971         memset(msg->data + msg->len, padding, padding);
 972         msg->len += padding;
 973         return 0;
 974 }
 975
 976 static
 977 int krb5_encrypt_rawobjs(struct crypto_blkcipher *tfm,
 978                          int mode_ecb,
 979                          int inobj_cnt,
 980                          rawobj_t *inobjs,
 981                          rawobj_t *outobj,
 982                          int enc)
 983 {
 984         struct blkcipher_desc desc;
 985         struct scatterlist    src, dst;
 986         struct sg_table         sg_src, sg_dst;
 987         __u8                  local_iv[16] = {0}, *buf;
 988         __u32                 datalen = 0;
 989         int                   i, rc;
 990         ENTRY;
 991
 992         buf = outobj->data;
 993         desc.tfm  = tfm;
 994         desc.info = local_iv;
 995         desc.flags = 0;
 996
 997         for (i = 0; i < inobj_cnt; i++) {
 998                 LASSERT(buf + inobjs[i].len <= outobj->data + outobj->len);
 999
1000                 rc = setup_sgtable(&sg_src, &src, inobjs[i].data,
1001                                    inobjs[i].len);
1002                 if (rc != 0)
1003                         RETURN(rc);
1004
1005                 rc = setup_sgtable(&sg_dst, &dst, buf,
1006                                    outobj->len - datalen);
1007                 if (rc != 0) {
1008                         teardown_sgtable(&sg_src);
1009                         RETURN(rc);
1010                 }
1011
1012                 if (mode_ecb) {
1013                         if (enc)
1014                                 rc = crypto_blkcipher_encrypt(&desc, sg_dst.sgl,
1015                                                               sg_src.sgl,
1016                                                               inobjs[i].len);
1017                         else
1018                                 rc = crypto_blkcipher_decrypt(&desc, sg_dst.sgl,
1019                                                               sg_src.sgl,
1020                                                               inobjs[i].len);
1021                 } else {
1022                         if (enc)
1023                                 rc = crypto_blkcipher_encrypt_iv(&desc,
1024                                                                  sg_dst.sgl,
1025                                                                  sg_src.sgl,
1026                                                                  inobjs[i].len);
1027                         else
1028                                 rc = crypto_blkcipher_decrypt_iv(&desc,
1029                                                                  sg_dst.sgl,
1030                                                                  sg_src.sgl,
1031                                                                  inobjs[i].len);
1032                 }
1033
1034                 teardown_sgtable(&sg_src);
1035                 teardown_sgtable(&sg_dst);
1036
1037                 if (rc) {
1038                         CERROR("encrypt error %d\n", rc);
1039                         RETURN(rc);
1040                 }
1041
1042                 datalen += inobjs[i].len;
1043                 buf += inobjs[i].len;
1044         }
1045
1046         outobj->len = datalen;
1047         RETURN(0);
1048 }
1049
1050 /*
1051  * if adj_nob != 0, we adjust desc->bd_nob to the actual cipher text size.
1052  */
1053 static
1054 int krb5_encrypt_bulk(struct crypto_blkcipher *tfm,
1055                       struct krb5_header *khdr,
1056                       char *confounder,
1057                       struct ptlrpc_bulk_desc *desc,
1058                       rawobj_t *cipher,
1059                       int adj_nob)
1060 {
1061         struct blkcipher_desc   ciph_desc;
1062         __u8                    local_iv[16] = {0};
1063         struct scatterlist      src, dst;
1064         struct sg_table         sg_src, sg_dst;
1065         int                     blocksize, i, rc, nob = 0;
1066
1067         LASSERT(ptlrpc_is_bulk_desc_kiov(desc->bd_type));
1068         LASSERT(desc->bd_iov_count);
1069         LASSERT(GET_ENC_KIOV(desc));
1070
1071         blocksize = crypto_blkcipher_blocksize(tfm);
1072         LASSERT(blocksize > 1);
1073         LASSERT(cipher->len == blocksize + sizeof(*khdr));
1074
1075         ciph_desc.tfm  = tfm;
1076         ciph_desc.info = local_iv;
1077         ciph_desc.flags = 0;
1078
1079         /* encrypt confounder */
1080         rc = setup_sgtable(&sg_src, &src, confounder, blocksize);
1081         if (rc != 0)
1082                 return rc;
1083
1084         rc = setup_sgtable(&sg_dst, &dst, cipher->data, blocksize);
1085         if (rc != 0) {
1086                 teardown_sgtable(&sg_src);
1087                 return rc;
1088         }
1089
1090         rc = crypto_blkcipher_encrypt_iv(&ciph_desc, sg_dst.sgl,
1091                                          sg_src.sgl, blocksize);
1092
1093         teardown_sgtable(&sg_dst);
1094         teardown_sgtable(&sg_src);
1095
1096         if (rc) {
1097                 CERROR("error to encrypt confounder: %d\n", rc);
1098                 return rc;
1099         }
1100
1101         /* encrypt clear pages */
1102         for (i = 0; i < desc->bd_iov_count; i++) {
1103                 sg_init_table(&src, 1);
1104                 sg_set_page(&src, BD_GET_KIOV(desc, i).kiov_page,
1105                             (BD_GET_KIOV(desc, i).kiov_len +
1106                                 blocksize - 1) &
1107                             (~(blocksize - 1)),
1108                             BD_GET_KIOV(desc, i).kiov_offset);
1109                 if (adj_nob)
1110                         nob += src.length;
1111                 sg_init_table(&dst, 1);
1112                 sg_set_page(&dst, BD_GET_ENC_KIOV(desc, i).kiov_page,
1113                             src.length, src.offset);
1114
1115                 BD_GET_ENC_KIOV(desc, i).kiov_offset = dst.offset;
1116                 BD_GET_ENC_KIOV(desc, i).kiov_len = dst.length;
1117
1118                 rc = crypto_blkcipher_encrypt_iv(&ciph_desc, &dst, &src,
1119                                                     src.length);
1120                 if (rc) {
1121                         CERROR("error to encrypt page: %d\n", rc);
1122                         return rc;
1123                 }
1124         }
1125
1126         /* encrypt krb5 header */
1127         rc = setup_sgtable(&sg_src, &src, khdr, sizeof(*khdr));
1128         if (rc != 0)
1129                 return rc;
1130
1131         rc = setup_sgtable(&sg_dst, &dst, cipher->data + blocksize,
1132                            sizeof(*khdr));
1133         if (rc != 0) {
1134                 teardown_sgtable(&sg_src);
1135                 return rc;
1136         }
1137
1138         rc = crypto_blkcipher_encrypt_iv(&ciph_desc, sg_dst.sgl, sg_src.sgl,
1139                                          sizeof(*khdr));
1140
1141         teardown_sgtable(&sg_dst);
1142         teardown_sgtable(&sg_src);
1143
1144         if (rc) {
1145                 CERROR("error to encrypt krb5 header: %d\n", rc);
1146                 return rc;
1147         }
1148
1149         if (adj_nob)
1150                 desc->bd_nob = nob;
1151
1152         return 0;
1153 }
1154
1155 /*
1156  * desc->bd_nob_transferred is the size of cipher text received.
1157  * desc->bd_nob is the target size of plain text supposed to be.
1158  *
1159  * if adj_nob != 0, we adjust each page's kiov_len to the actual
1160  * plain text size.
1161  * - for client read: we don't know data size for each page, so
1162  *   bd_iov[]->kiov_len is set to PAGE_SIZE, but actual data received might
1163  *   be smaller, so we need to adjust it according to
1164  *   bd_u.bd_kiov.bd_enc_vec[]->kiov_len.
1165  *   this means we DO NOT support the situation that server send an odd size
1166  *   data in a page which is not the last one.
1167  * - for server write: we knows exactly data size for each page being expected,
1168  *   thus kiov_len is accurate already, so we should not adjust it at all.
1169  *   and bd_u.bd_kiov.bd_enc_vec[]->kiov_len should be
1170  *   round_up(bd_iov[]->kiov_len) which
1171  *   should have been done by prep_bulk().
1172  */
1173 static
1174 int krb5_decrypt_bulk(struct crypto_blkcipher *tfm,
1175                       struct krb5_header *khdr,
1176                       struct ptlrpc_bulk_desc *desc,
1177                       rawobj_t *cipher,
1178                       rawobj_t *plain,
1179                       int adj_nob)
1180 {
1181         struct blkcipher_desc   ciph_desc;
1182         __u8                    local_iv[16] = {0};
1183         struct scatterlist      src, dst;
1184         struct sg_table         sg_src, sg_dst;
1185         int                     ct_nob = 0, pt_nob = 0;
1186         int                     blocksize, i, rc;
1187
1188         LASSERT(ptlrpc_is_bulk_desc_kiov(desc->bd_type));
1189         LASSERT(desc->bd_iov_count);
1190         LASSERT(GET_ENC_KIOV(desc));
1191         LASSERT(desc->bd_nob_transferred);
1192
1193         blocksize = crypto_blkcipher_blocksize(tfm);
1194         LASSERT(blocksize > 1);
1195         LASSERT(cipher->len == blocksize + sizeof(*khdr));
1196
1197         ciph_desc.tfm  = tfm;
1198         ciph_desc.info = local_iv;
1199         ciph_desc.flags = 0;
1200
1201         if (desc->bd_nob_transferred % blocksize) {
1202                 CERROR("odd transferred nob: %d\n", desc->bd_nob_transferred);
1203                 return -EPROTO;
1204         }
1205
1206         /* decrypt head (confounder) */
1207         rc = setup_sgtable(&sg_src, &src, cipher->data, blocksize);
1208         if (rc != 0)
1209                 return rc;
1210
1211         rc = setup_sgtable(&sg_dst, &dst, plain->data, blocksize);
1212         if (rc != 0) {
1213                 teardown_sgtable(&sg_src);
1214                 return rc;
1215         }
1216
1217         rc = crypto_blkcipher_decrypt_iv(&ciph_desc, sg_dst.sgl,
1218                                          sg_src.sgl, blocksize);
1219
1220         teardown_sgtable(&sg_dst);
1221         teardown_sgtable(&sg_src);
1222
1223         if (rc) {
1224                 CERROR("error to decrypt confounder: %d\n", rc);
1225                 return rc;
1226         }
1227
1228         for (i = 0; i < desc->bd_iov_count && ct_nob < desc->bd_nob_transferred;
1229              i++) {
1230                 if (BD_GET_ENC_KIOV(desc, i).kiov_offset % blocksize
1231                     != 0 ||
1232                     BD_GET_ENC_KIOV(desc, i).kiov_len % blocksize
1233                     != 0) {
1234                         CERROR("page %d: odd offset %u len %u, blocksize %d\n",
1235                                i, BD_GET_ENC_KIOV(desc, i).kiov_offset,
1236                                BD_GET_ENC_KIOV(desc, i).kiov_len,
1237                                blocksize);
1238                         return -EFAULT;
1239                 }
1240
1241                 if (adj_nob) {
1242                         if (ct_nob + BD_GET_ENC_KIOV(desc, i).kiov_len >
1243                             desc->bd_nob_transferred)
1244                                 BD_GET_ENC_KIOV(desc, i).kiov_len =
1245                                         desc->bd_nob_transferred - ct_nob;
1246
1247                         BD_GET_KIOV(desc, i).kiov_len =
1248                           BD_GET_ENC_KIOV(desc, i).kiov_len;
1249                         if (pt_nob + BD_GET_ENC_KIOV(desc, i).kiov_len >
1250                             desc->bd_nob)
1251                                 BD_GET_KIOV(desc, i).kiov_len =
1252                                   desc->bd_nob - pt_nob;
1253                 } else {
1254                         /* this should be guaranteed by LNET */
1255                         LASSERT(ct_nob + BD_GET_ENC_KIOV(desc, i).
1256                                 kiov_len <=
1257                                 desc->bd_nob_transferred);
1258                         LASSERT(BD_GET_KIOV(desc, i).kiov_len <=
1259                                 BD_GET_ENC_KIOV(desc, i).kiov_len);
1260                 }
1261
1262                 if (BD_GET_ENC_KIOV(desc, i).kiov_len == 0)
1263                         continue;
1264
1265                 sg_init_table(&src, 1);
1266                 sg_set_page(&src, BD_GET_ENC_KIOV(desc, i).kiov_page,
1267                             BD_GET_ENC_KIOV(desc, i).kiov_len,
1268                             BD_GET_ENC_KIOV(desc, i).kiov_offset);
1269                 dst = src;
1270                 if (BD_GET_KIOV(desc, i).kiov_len % blocksize == 0)
1271                         sg_assign_page(&dst,
1272                                        BD_GET_KIOV(desc, i).kiov_page);
1273
1274                 rc = crypto_blkcipher_decrypt_iv(&ciph_desc, &dst, &src,
1275                                                  src.length);
1276                 if (rc) {
1277                         CERROR("error to decrypt page: %d\n", rc);
1278                         return rc;
1279                 }
1280
1281                 if (BD_GET_KIOV(desc, i).kiov_len % blocksize != 0) {
1282                         memcpy(page_address(BD_GET_KIOV(desc, i).kiov_page) +
1283                                BD_GET_KIOV(desc, i).kiov_offset,
1284                                page_address(BD_GET_ENC_KIOV(desc, i).
1285                                             kiov_page) +
1286                                BD_GET_KIOV(desc, i).kiov_offset,
1287                                BD_GET_KIOV(desc, i).kiov_len);
1288                 }
1289
1290                 ct_nob += BD_GET_ENC_KIOV(desc, i).kiov_len;
1291                 pt_nob += BD_GET_KIOV(desc, i).kiov_len;
1292         }
1293
1294         if (unlikely(ct_nob != desc->bd_nob_transferred)) {
1295                 CERROR("%d cipher text transferred but only %d decrypted\n",
1296                        desc->bd_nob_transferred, ct_nob);
1297                 return -EFAULT;
1298         }
1299
1300         if (unlikely(!adj_nob && pt_nob != desc->bd_nob)) {
1301                 CERROR("%d plain text expected but only %d received\n",
1302                        desc->bd_nob, pt_nob);
1303                 return -EFAULT;
1304         }
1305
1306         /* if needed, clear up the rest unused iovs */
1307         if (adj_nob)
1308                 while (i < desc->bd_iov_count)
1309                         BD_GET_KIOV(desc, i++).kiov_len = 0;
1310
1311         /* decrypt tail (krb5 header) */
1312         rc = setup_sgtable(&sg_src, &src, cipher->data + blocksize,
1313                            sizeof(*khdr));
1314         if (rc != 0)
1315                 return rc;
1316
1317         rc = setup_sgtable(&sg_dst, &dst, cipher->data + blocksize,
1318                            sizeof(*khdr));
1319         if (rc != 0) {
1320                 teardown_sgtable(&sg_src);
1321                 return rc;
1322         }
1323
1324         rc = crypto_blkcipher_decrypt_iv(&ciph_desc, sg_dst.sgl, sg_src.sgl,
1325                                          sizeof(*khdr));
1326
1327         teardown_sgtable(&sg_src);
1328         teardown_sgtable(&sg_dst);
1329
1330         if (rc) {
1331                 CERROR("error to decrypt tail: %d\n", rc);
1332                 return rc;
1333         }
1334
1335         if (memcmp(cipher->data + blocksize, khdr, sizeof(*khdr))) {
1336                 CERROR("krb5 header doesn't match\n");
1337                 return -EACCES;
1338         }
1339
1340         return 0;
1341 }
1342
1343 static
1344 __u32 gss_wrap_kerberos(struct gss_ctx *gctx,
1345                         rawobj_t *gsshdr,
1346                         rawobj_t *msg,
1347                         int msg_buflen,
1348                         rawobj_t *token)
1349 {
1350         struct krb5_ctx     *kctx = gctx->internal_ctx_id;
1351         struct krb5_enctype *ke = &enctypes[kctx->kc_enctype];
1352         struct krb5_header  *khdr;
1353         int                  blocksize;
1354         rawobj_t             cksum = RAWOBJ_EMPTY;
1355         rawobj_t             data_desc[3], cipher;
1356         __u8                 conf[GSS_MAX_CIPHER_BLOCK];
1357         int                  rc = 0;
1358
1359         LASSERT(ke);
1360         LASSERT(ke->ke_conf_size <= GSS_MAX_CIPHER_BLOCK);
1361         LASSERT(kctx->kc_keye.kb_tfm == NULL ||
1362                 ke->ke_conf_size >=
1363                 crypto_blkcipher_blocksize(kctx->kc_keye.kb_tfm));
1364
1365         /*
1366          * final token format:
1367          * ---------------------------------------------------
1368          * | krb5 header | cipher text | checksum (16 bytes) |
1369          * ---------------------------------------------------
1370          */
1371
1372         /* fill krb5 header */
1373         LASSERT(token->len >= sizeof(*khdr));
1374         khdr = (struct krb5_header *) token->data;
1375         fill_krb5_header(kctx, khdr, 1);
1376
1377         /* generate confounder */
1378         cfs_get_random_bytes(conf, ke->ke_conf_size);
1379
1380         /* get encryption blocksize. note kc_keye might not associated with
1381          * a tfm, currently only for arcfour-hmac */
1382         if (kctx->kc_enctype == ENCTYPE_ARCFOUR_HMAC) {
1383                 LASSERT(kctx->kc_keye.kb_tfm == NULL);
1384                 blocksize = 1;
1385         } else {
1386                 LASSERT(kctx->kc_keye.kb_tfm);
1387                 blocksize = crypto_blkcipher_blocksize(kctx->kc_keye.kb_tfm);
1388         }
1389         LASSERT(blocksize <= ke->ke_conf_size);
1390
1391         /* padding the message */
1392         if (add_padding(msg, msg_buflen, blocksize))
1393                 return GSS_S_FAILURE;
1394
1395         /*
1396          * clear text layout for checksum:
1397          * ------------------------------------------------------
1398          * | confounder | gss header | clear msgs | krb5 header |
1399          * ------------------------------------------------------
1400          */
1401         data_desc[0].data = conf;
1402         data_desc[0].len = ke->ke_conf_size;
1403         data_desc[1].data = gsshdr->data;
1404         data_desc[1].len = gsshdr->len;
1405         data_desc[2].data = msg->data;
1406         data_desc[2].len = msg->len;
1407
1408         /* compute checksum */
1409         if (krb5_make_checksum(kctx->kc_enctype, &kctx->kc_keyi,
1410                                khdr, 3, data_desc, 0, NULL, &cksum))
1411                 return GSS_S_FAILURE;
1412         LASSERT(cksum.len >= ke->ke_hash_size);
1413
1414         /*
1415          * clear text layout for encryption:
1416          * -----------------------------------------
1417          * | confounder | clear msgs | krb5 header |
1418          * -----------------------------------------
1419          */
1420         data_desc[0].data = conf;
1421         data_desc[0].len = ke->ke_conf_size;
1422         data_desc[1].data = msg->data;
1423         data_desc[1].len = msg->len;
1424         data_desc[2].data = (__u8 *) khdr;
1425         data_desc[2].len = sizeof(*khdr);
1426
1427         /* cipher text will be directly inplace */
1428         cipher.data = (__u8 *) (khdr + 1);
1429         cipher.len = token->len - sizeof(*khdr);
1430         LASSERT(cipher.len >= ke->ke_conf_size + msg->len + sizeof(*khdr));
1431
1432         if (kctx->kc_enctype == ENCTYPE_ARCFOUR_HMAC) {
1433                 rawobj_t                 arc4_keye;
1434                 struct crypto_blkcipher *arc4_tfm;
1435
1436                 if (krb5_make_checksum(ENCTYPE_ARCFOUR_HMAC, &kctx->kc_keyi,
1437                                        NULL, 1, &cksum, 0, NULL, &arc4_keye)) {
1438                         CERROR("failed to obtain arc4 enc key\n");
1439                         GOTO(arc4_out, rc = -EACCES);
1440                 }
1441
1442                 arc4_tfm = crypto_alloc_blkcipher("ecb(arc4)", 0, 0);
1443                 if (IS_ERR(arc4_tfm)) {
1444                         CERROR("failed to alloc tfm arc4 in ECB mode\n");
1445                         GOTO(arc4_out_key, rc = -EACCES);
1446                 }
1447
1448                 if (crypto_blkcipher_setkey(arc4_tfm, arc4_keye.data,
1449                                                arc4_keye.len)) {
1450                         CERROR("failed to set arc4 key, len %d\n",
1451                                arc4_keye.len);
1452                         GOTO(arc4_out_tfm, rc = -EACCES);
1453                 }
1454
1455                 rc = krb5_encrypt_rawobjs(arc4_tfm, 1,
1456                                           3, data_desc, &cipher, 1);
1457 arc4_out_tfm:
1458                 crypto_free_blkcipher(arc4_tfm);
1459 arc4_out_key:
1460                 rawobj_free(&arc4_keye);
1461 arc4_out:
1462                 do {} while(0); /* just to avoid compile warning */
1463         } else {
1464                 rc = krb5_encrypt_rawobjs(kctx->kc_keye.kb_tfm, 0,
1465                                           3, data_desc, &cipher, 1);
1466         }
1467
1468         if (rc != 0) {
1469                 rawobj_free(&cksum);
1470                 return GSS_S_FAILURE;
1471         }
1472
1473         /* fill in checksum */
1474         LASSERT(token->len >= sizeof(*khdr) + cipher.len + ke->ke_hash_size);
1475         memcpy((char *)(khdr + 1) + cipher.len,
1476                cksum.data + cksum.len - ke->ke_hash_size,
1477                ke->ke_hash_size);
1478         rawobj_free(&cksum);
1479
1480         /* final token length */
1481         token->len = sizeof(*khdr) + cipher.len + ke->ke_hash_size;
1482         return GSS_S_COMPLETE;
1483 }
1484
1485 static
1486 __u32 gss_prep_bulk_kerberos(struct gss_ctx *gctx,
1487                              struct ptlrpc_bulk_desc *desc)
1488 {
1489         struct krb5_ctx     *kctx = gctx->internal_ctx_id;
1490         int                  blocksize, i;
1491
1492         LASSERT(ptlrpc_is_bulk_desc_kiov(desc->bd_type));
1493         LASSERT(desc->bd_iov_count);
1494         LASSERT(GET_ENC_KIOV(desc));
1495         LASSERT(kctx->kc_keye.kb_tfm);
1496
1497         blocksize = crypto_blkcipher_blocksize(kctx->kc_keye.kb_tfm);
1498
1499         for (i = 0; i < desc->bd_iov_count; i++) {
1500                 LASSERT(BD_GET_ENC_KIOV(desc, i).kiov_page);
1501                 /*
1502                  * offset should always start at page boundary of either
1503                  * client or server side.
1504                  */
1505                 if (BD_GET_KIOV(desc, i).kiov_offset & blocksize) {
1506                         CERROR("odd offset %d in page %d\n",
1507                                BD_GET_KIOV(desc, i).kiov_offset, i);
1508                         return GSS_S_FAILURE;
1509                 }
1510
1511                 BD_GET_ENC_KIOV(desc, i).kiov_offset =
1512                         BD_GET_KIOV(desc, i).kiov_offset;
1513                 BD_GET_ENC_KIOV(desc, i).kiov_len =
1514                         (BD_GET_KIOV(desc, i).kiov_len +
1515                          blocksize - 1) & (~(blocksize - 1));
1516         }
1517
1518         return GSS_S_COMPLETE;
1519 }
1520
1521 static
1522 __u32 gss_wrap_bulk_kerberos(struct gss_ctx *gctx,
1523                              struct ptlrpc_bulk_desc *desc,
1524                              rawobj_t *token, int adj_nob)
1525 {
1526         struct krb5_ctx     *kctx = gctx->internal_ctx_id;
1527         struct krb5_enctype *ke = &enctypes[kctx->kc_enctype];
1528         struct krb5_header  *khdr;
1529         int                  blocksize;
1530         rawobj_t             cksum = RAWOBJ_EMPTY;
1531         rawobj_t             data_desc[1], cipher;
1532         __u8                 conf[GSS_MAX_CIPHER_BLOCK];
1533         int                  rc = 0;
1534
1535         LASSERT(ptlrpc_is_bulk_desc_kiov(desc->bd_type));
1536         LASSERT(ke);
1537         LASSERT(ke->ke_conf_size <= GSS_MAX_CIPHER_BLOCK);
1538
1539         /*
1540          * final token format:
1541          * --------------------------------------------------
1542          * | krb5 header | head/tail cipher text | checksum |
1543          * --------------------------------------------------
1544          */
1545
1546         /* fill krb5 header */
1547         LASSERT(token->len >= sizeof(*khdr));
1548         khdr = (struct krb5_header *) token->data;
1549         fill_krb5_header(kctx, khdr, 1);
1550
1551         /* generate confounder */
1552         cfs_get_random_bytes(conf, ke->ke_conf_size);
1553
1554         /* get encryption blocksize. note kc_keye might not associated with
1555          * a tfm, currently only for arcfour-hmac */
1556         if (kctx->kc_enctype == ENCTYPE_ARCFOUR_HMAC) {
1557                 LASSERT(kctx->kc_keye.kb_tfm == NULL);
1558                 blocksize = 1;
1559         } else {
1560                 LASSERT(kctx->kc_keye.kb_tfm);
1561                 blocksize = crypto_blkcipher_blocksize(kctx->kc_keye.kb_tfm);
1562         }
1563
1564         /*
1565          * we assume the size of krb5_header (16 bytes) must be n * blocksize.
1566          * the bulk token size would be exactly (sizeof(krb5_header) +
1567          * blocksize + sizeof(krb5_header) + hashsize)
1568          */
1569         LASSERT(blocksize <= ke->ke_conf_size);
1570         LASSERT(sizeof(*khdr) >= blocksize && sizeof(*khdr) % blocksize == 0);
1571         LASSERT(token->len >= sizeof(*khdr) + blocksize + sizeof(*khdr) + 16);
1572
1573         /*
1574          * clear text layout for checksum:
1575          * ------------------------------------------
1576          * | confounder | clear pages | krb5 header |
1577          * ------------------------------------------
1578          */
1579         data_desc[0].data = conf;
1580         data_desc[0].len = ke->ke_conf_size;
1581
1582         /* compute checksum */
1583         if (krb5_make_checksum(kctx->kc_enctype, &kctx->kc_keyi,
1584                                khdr, 1, data_desc,
1585                                desc->bd_iov_count, GET_KIOV(desc),
1586                                &cksum))
1587                 return GSS_S_FAILURE;
1588         LASSERT(cksum.len >= ke->ke_hash_size);
1589
1590         /*
1591          * clear text layout for encryption:
1592          * ------------------------------------------
1593          * | confounder | clear pages | krb5 header |
1594          * ------------------------------------------
1595          *        |              |             |
1596          *        ----------  (cipher pages)   |
1597          * result token:   |                   |
1598          * -------------------------------------------
1599          * | krb5 header | cipher text | cipher text |
1600          * -------------------------------------------
1601          */
1602         data_desc[0].data = conf;
1603         data_desc[0].len = ke->ke_conf_size;
1604
1605         cipher.data = (__u8 *) (khdr + 1);
1606         cipher.len = blocksize + sizeof(*khdr);
1607
1608         if (kctx->kc_enctype == ENCTYPE_ARCFOUR_HMAC) {
1609                 LBUG();
1610                 rc = 0;
1611         } else {
1612                 rc = krb5_encrypt_bulk(kctx->kc_keye.kb_tfm, khdr,
1613                                        conf, desc, &cipher, adj_nob);
1614         }
1615
1616         if (rc != 0) {
1617                 rawobj_free(&cksum);
1618                 return GSS_S_FAILURE;
1619         }
1620
1621         /* fill in checksum */
1622         LASSERT(token->len >= sizeof(*khdr) + cipher.len + ke->ke_hash_size);
1623         memcpy((char *)(khdr + 1) + cipher.len,
1624                cksum.data + cksum.len - ke->ke_hash_size,
1625                ke->ke_hash_size);
1626         rawobj_free(&cksum);
1627
1628         /* final token length */
1629         token->len = sizeof(*khdr) + cipher.len + ke->ke_hash_size;
1630         return GSS_S_COMPLETE;
1631 }
1632
1633 static
1634 __u32 gss_unwrap_kerberos(struct gss_ctx  *gctx,
1635                           rawobj_t        *gsshdr,
1636                           rawobj_t        *token,
1637                           rawobj_t        *msg)
1638 {
1639         struct krb5_ctx     *kctx = gctx->internal_ctx_id;
1640         struct krb5_enctype *ke = &enctypes[kctx->kc_enctype];
1641         struct krb5_header  *khdr;
1642         unsigned char       *tmpbuf;
1643         int                  blocksize, bodysize;
1644         rawobj_t             cksum = RAWOBJ_EMPTY;
1645         rawobj_t             cipher_in, plain_out;
1646         rawobj_t             hash_objs[3];
1647         int                  rc = 0;
1648         __u32                major;
1649
1650         LASSERT(ke);
1651
1652         if (token->len < sizeof(*khdr)) {
1653                 CERROR("short signature: %u\n", token->len);
1654                 return GSS_S_DEFECTIVE_TOKEN;
1655         }
1656
1657         khdr = (struct krb5_header *) token->data;
1658
1659         major = verify_krb5_header(kctx, khdr, 1);
1660         if (major != GSS_S_COMPLETE) {
1661                 CERROR("bad krb5 header\n");
1662                 return major;
1663         }
1664
1665         /* block size */
1666         if (kctx->kc_enctype == ENCTYPE_ARCFOUR_HMAC) {
1667                 LASSERT(kctx->kc_keye.kb_tfm == NULL);
1668                 blocksize = 1;
1669         } else {
1670                 LASSERT(kctx->kc_keye.kb_tfm);
1671                 blocksize = crypto_blkcipher_blocksize(kctx->kc_keye.kb_tfm);
1672         }
1673
1674         /* expected token layout:
1675          * ----------------------------------------
1676          * | krb5 header | cipher text | checksum |
1677          * ----------------------------------------
1678          */
1679         bodysize = token->len - sizeof(*khdr) - ke->ke_hash_size;
1680
1681         if (bodysize % blocksize) {
1682                 CERROR("odd bodysize %d\n", bodysize);
1683                 return GSS_S_DEFECTIVE_TOKEN;
1684         }
1685
1686         if (bodysize <= ke->ke_conf_size + sizeof(*khdr)) {
1687                 CERROR("incomplete token: bodysize %d\n", bodysize);
1688                 return GSS_S_DEFECTIVE_TOKEN;
1689         }
1690
1691         if (msg->len < bodysize - ke->ke_conf_size - sizeof(*khdr)) {
1692                 CERROR("buffer too small: %u, require %d\n",
1693                        msg->len, bodysize - ke->ke_conf_size);
1694                 return GSS_S_FAILURE;
1695         }
1696
1697         /* decrypting */
1698         OBD_ALLOC_LARGE(tmpbuf, bodysize);
1699         if (!tmpbuf)
1700                 return GSS_S_FAILURE;
1701
1702         major = GSS_S_FAILURE;
1703
1704         cipher_in.data = (__u8 *) (khdr + 1);
1705         cipher_in.len = bodysize;
1706         plain_out.data = tmpbuf;
1707         plain_out.len = bodysize;
1708
1709         if (kctx->kc_enctype == ENCTYPE_ARCFOUR_HMAC) {
1710                 rawobj_t                 arc4_keye;
1711                 struct crypto_blkcipher *arc4_tfm;
1712
1713                 cksum.data = token->data + token->len - ke->ke_hash_size;
1714                 cksum.len = ke->ke_hash_size;
1715
1716                 if (krb5_make_checksum(ENCTYPE_ARCFOUR_HMAC, &kctx->kc_keyi,
1717                                        NULL, 1, &cksum, 0, NULL, &arc4_keye)) {
1718                         CERROR("failed to obtain arc4 enc key\n");
1719                         GOTO(arc4_out, rc = -EACCES);
1720                 }
1721
1722                 arc4_tfm = crypto_alloc_blkcipher("ecb(arc4)", 0, 0);
1723                 if (IS_ERR(arc4_tfm)) {
1724                         CERROR("failed to alloc tfm arc4 in ECB mode\n");
1725                         GOTO(arc4_out_key, rc = -EACCES);
1726                 }
1727
1728                 if (crypto_blkcipher_setkey(arc4_tfm,
1729                                          arc4_keye.data, arc4_keye.len)) {
1730                         CERROR("failed to set arc4 key, len %d\n",
1731                                arc4_keye.len);
1732                         GOTO(arc4_out_tfm, rc = -EACCES);
1733                 }
1734
1735                 rc = krb5_encrypt_rawobjs(arc4_tfm, 1,
1736                                           1, &cipher_in, &plain_out, 0);
1737 arc4_out_tfm:
1738                 crypto_free_blkcipher(arc4_tfm);
1739 arc4_out_key:
1740                 rawobj_free(&arc4_keye);
1741 arc4_out:
1742                 cksum = RAWOBJ_EMPTY;
1743         } else {
1744                 rc = krb5_encrypt_rawobjs(kctx->kc_keye.kb_tfm, 0,
1745                                           1, &cipher_in, &plain_out, 0);
1746         }
1747
1748         if (rc != 0) {
1749                 CERROR("error decrypt\n");
1750                 goto out_free;
1751         }
1752         LASSERT(plain_out.len == bodysize);
1753
1754         /* expected clear text layout:
1755          * -----------------------------------------
1756          * | confounder | clear msgs | krb5 header |
1757          * -----------------------------------------
1758          */
1759
1760         /* verify krb5 header in token is not modified */
1761         if (memcmp(khdr, plain_out.data + plain_out.len - sizeof(*khdr),
1762                    sizeof(*khdr))) {
1763                 CERROR("decrypted krb5 header mismatch\n");
1764                 goto out_free;
1765         }
1766
1767         /* verify checksum, compose clear text as layout:
1768          * ------------------------------------------------------
1769          * | confounder | gss header | clear msgs | krb5 header |
1770          * ------------------------------------------------------
1771          */
1772         hash_objs[0].len = ke->ke_conf_size;
1773         hash_objs[0].data = plain_out.data;
1774         hash_objs[1].len = gsshdr->len;
1775         hash_objs[1].data = gsshdr->data;
1776         hash_objs[2].len = plain_out.len - ke->ke_conf_size - sizeof(*khdr);
1777         hash_objs[2].data = plain_out.data + ke->ke_conf_size;
1778         if (krb5_make_checksum(kctx->kc_enctype, &kctx->kc_keyi,
1779                                khdr, 3, hash_objs, 0, NULL, &cksum))
1780                 goto out_free;
1781
1782         LASSERT(cksum.len >= ke->ke_hash_size);
1783         if (memcmp((char *)(khdr + 1) + bodysize,
1784                    cksum.data + cksum.len - ke->ke_hash_size,
1785                    ke->ke_hash_size)) {
1786                 CERROR("checksum mismatch\n");
1787                 goto out_free;
1788         }
1789
1790         msg->len =  bodysize - ke->ke_conf_size - sizeof(*khdr);
1791         memcpy(msg->data, tmpbuf + ke->ke_conf_size, msg->len);
1792
1793         major = GSS_S_COMPLETE;
1794 out_free:
1795         OBD_FREE_LARGE(tmpbuf, bodysize);
1796         rawobj_free(&cksum);
1797         return major;
1798 }
1799
1800 static
1801 __u32 gss_unwrap_bulk_kerberos(struct gss_ctx *gctx,
1802                                struct ptlrpc_bulk_desc *desc,
1803                                rawobj_t *token, int adj_nob)
1804 {
1805         struct krb5_ctx     *kctx = gctx->internal_ctx_id;
1806         struct krb5_enctype *ke = &enctypes[kctx->kc_enctype];
1807         struct krb5_header  *khdr;
1808         int                  blocksize;
1809         rawobj_t             cksum = RAWOBJ_EMPTY;
1810         rawobj_t             cipher, plain;
1811         rawobj_t             data_desc[1];
1812         int                  rc;
1813         __u32                major;
1814
1815         LASSERT(ptlrpc_is_bulk_desc_kiov(desc->bd_type));
1816         LASSERT(ke);
1817
1818         if (token->len < sizeof(*khdr)) {
1819                 CERROR("short signature: %u\n", token->len);
1820                 return GSS_S_DEFECTIVE_TOKEN;
1821         }
1822
1823         khdr = (struct krb5_header *) token->data;
1824
1825         major = verify_krb5_header(kctx, khdr, 1);
1826         if (major != GSS_S_COMPLETE) {
1827                 CERROR("bad krb5 header\n");
1828                 return major;
1829         }
1830
1831         /* block size */
1832         if (kctx->kc_enctype == ENCTYPE_ARCFOUR_HMAC) {
1833                 LASSERT(kctx->kc_keye.kb_tfm == NULL);
1834                 blocksize = 1;
1835                 LBUG();
1836         } else {
1837                 LASSERT(kctx->kc_keye.kb_tfm);
1838                 blocksize = crypto_blkcipher_blocksize(kctx->kc_keye.kb_tfm);
1839         }
1840         LASSERT(sizeof(*khdr) >= blocksize && sizeof(*khdr) % blocksize == 0);
1841
1842         /*
1843          * token format is expected as:
1844          * -----------------------------------------------
1845          * | krb5 header | head/tail cipher text | cksum |
1846          * -----------------------------------------------
1847          */
1848         if (token->len < sizeof(*khdr) + blocksize + sizeof(*khdr) +
1849                          ke->ke_hash_size) {
1850                 CERROR("short token size: %u\n", token->len);
1851                 return GSS_S_DEFECTIVE_TOKEN;
1852         }
1853
1854         cipher.data = (__u8 *) (khdr + 1);
1855         cipher.len = blocksize + sizeof(*khdr);
1856         plain.data = cipher.data;
1857         plain.len = cipher.len;
1858
1859         rc = krb5_decrypt_bulk(kctx->kc_keye.kb_tfm, khdr,
1860                                desc, &cipher, &plain, adj_nob);
1861         if (rc)
1862                 return GSS_S_DEFECTIVE_TOKEN;
1863
1864         /*
1865          * verify checksum, compose clear text as layout:
1866          * ------------------------------------------
1867          * | confounder | clear pages | krb5 header |
1868          * ------------------------------------------
1869          */
1870         data_desc[0].data = plain.data;
1871         data_desc[0].len = blocksize;
1872
1873         if (krb5_make_checksum(kctx->kc_enctype, &kctx->kc_keyi,
1874                                khdr, 1, data_desc,
1875                                desc->bd_iov_count,
1876                                GET_KIOV(desc),
1877                                &cksum))
1878                 return GSS_S_FAILURE;
1879         LASSERT(cksum.len >= ke->ke_hash_size);
1880
1881         if (memcmp(plain.data + blocksize + sizeof(*khdr),
1882                    cksum.data + cksum.len - ke->ke_hash_size,
1883                    ke->ke_hash_size)) {
1884                 CERROR("checksum mismatch\n");
1885                 rawobj_free(&cksum);
1886                 return GSS_S_BAD_SIG;
1887         }
1888
1889         rawobj_free(&cksum);
1890         return GSS_S_COMPLETE;
1891 }
1892
1893 int gss_display_kerberos(struct gss_ctx        *ctx,
1894                          char                  *buf,
1895                          int                    bufsize)
1896 {
1897         struct krb5_ctx    *kctx = ctx->internal_ctx_id;
1898         int                 written;
1899
1900         written = snprintf(buf, bufsize, "krb5 (%s)",
1901                            enctype2str(kctx->kc_enctype));
1902         return written;
1903 }
1904
1905 static struct gss_api_ops gss_kerberos_ops = {
1906         .gss_import_sec_context     = gss_import_sec_context_kerberos,
1907         .gss_copy_reverse_context   = gss_copy_reverse_context_kerberos,
1908         .gss_inquire_context        = gss_inquire_context_kerberos,
1909         .gss_get_mic                = gss_get_mic_kerberos,
1910         .gss_verify_mic             = gss_verify_mic_kerberos,
1911         .gss_wrap                   = gss_wrap_kerberos,
1912         .gss_unwrap                 = gss_unwrap_kerberos,
1913         .gss_prep_bulk              = gss_prep_bulk_kerberos,
1914         .gss_wrap_bulk              = gss_wrap_bulk_kerberos,
1915         .gss_unwrap_bulk            = gss_unwrap_bulk_kerberos,
1916         .gss_delete_sec_context     = gss_delete_sec_context_kerberos,
1917         .gss_display                = gss_display_kerberos,
1918 };
1919
1920 static struct subflavor_desc gss_kerberos_sfs[] = {
1921         {
1922                 .sf_subflavor   = SPTLRPC_SUBFLVR_KRB5N,
1923                 .sf_qop         = 0,
1924                 .sf_service     = SPTLRPC_SVC_NULL,
1925                 .sf_name        = "krb5n"
1926         },
1927         {
1928                 .sf_subflavor   = SPTLRPC_SUBFLVR_KRB5A,
1929                 .sf_qop         = 0,
1930                 .sf_service     = SPTLRPC_SVC_AUTH,
1931                 .sf_name        = "krb5a"
1932         },
1933         {
1934                 .sf_subflavor   = SPTLRPC_SUBFLVR_KRB5I,
1935                 .sf_qop         = 0,
1936                 .sf_service     = SPTLRPC_SVC_INTG,
1937                 .sf_name        = "krb5i"
1938         },
1939         {
1940                 .sf_subflavor   = SPTLRPC_SUBFLVR_KRB5P,
1941                 .sf_qop         = 0,
1942                 .sf_service     = SPTLRPC_SVC_PRIV,
1943                 .sf_name        = "krb5p"
1944         },
1945 };
1946
1947 /*
1948  * currently we leave module owner NULL
1949  */
1950 static struct gss_api_mech gss_kerberos_mech = {
1951         .gm_owner       = NULL, /*THIS_MODULE, */
1952         .gm_name        = "krb5",
1953         .gm_oid         = (rawobj_t)
1954                                 {9, "\052\206\110\206\367\022\001\002\002"},
1955         .gm_ops         = &gss_kerberos_ops,
1956         .gm_sf_num      = 4,
1957         .gm_sfs         = gss_kerberos_sfs,
1958 };
1959
1960 int __init init_kerberos_module(void)
1961 {
1962         int status;
1963
1964         spin_lock_init(&krb5_seq_lock);
1965
1966         status = lgss_mech_register(&gss_kerberos_mech);
1967         if (status)
1968                 CERROR("Failed to register kerberos gss mechanism!\n");
1969         return status;
1970 }
1971
1972 void cleanup_kerberos_module(void)
1973 {
1974         lgss_mech_unregister(&gss_kerberos_mech);
1975 }