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/random.h>
  55 #include <linux/slab.h>
  56 #include <linux/crypto.h>
  57 #include <linux/mutex.h>
  58
  59 #include <obd.h>
  60 #include <obd_class.h>
  61 #include <obd_support.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 #include "gss_crypto.h"
  72
  73 static DEFINE_SPINLOCK(krb5_seq_lock);
  74
  75 struct krb5_enctype {
  76         char           *ke_dispname;
  77         char           *ke_enc_name;            /* linux tfm name */
  78         char           *ke_hash_name;           /* linux tfm name */
  79         int             ke_enc_mode;            /* linux tfm mode */
  80         int             ke_hash_size;           /* checksum size */
  81         int             ke_conf_size;           /* confounder size */
  82         unsigned int    ke_hash_hmac:1;         /* is hmac? */
  83 };
  84
  85 /*
  86  * NOTE: for aes128-cts and aes256-cts, MIT implementation use CTS encryption.
  87  * but currently we simply CBC with padding, because linux doesn't support CTS
  88  * yet. this need to be fixed in the future.
  89  */
  90 static struct krb5_enctype enctypes[] = {
  91         [ENCTYPE_DES_CBC_RAW] = {               /* des-cbc-md5 */
  92                 .ke_dispname    = "des-cbc-md5",
  93                 .ke_enc_name    = "cbc(des)",
  94                 .ke_hash_name   = "md5",
  95                 .ke_hash_size   = 16,
  96                 .ke_conf_size   = 8,
  97         },
  98 #ifdef HAVE_DES3_SUPPORT
  99         [ENCTYPE_DES3_CBC_RAW] = {              /* des3-hmac-sha1 */
 100                 .ke_dispname    = "des3-hmac-sha1",
 101                 .ke_enc_name    = "cbc(des3_ede)",
 102                 .ke_hash_name   = "sha1",
 103                 .ke_hash_size   = 20,
 104                 .ke_conf_size   = 8,
 105                 .ke_hash_hmac   = 1,
 106         },
 107 #endif
 108         [ENCTYPE_AES128_CTS_HMAC_SHA1_96] = {   /* aes128-cts */
 109                 .ke_dispname    = "aes128-cts-hmac-sha1-96",
 110                 .ke_enc_name    = "cbc(aes)",
 111                 .ke_hash_name   = "sha1",
 112                 .ke_hash_size   = 12,
 113                 .ke_conf_size   = 16,
 114                 .ke_hash_hmac   = 1,
 115         },
 116         [ENCTYPE_AES256_CTS_HMAC_SHA1_96] = {   /* aes256-cts */
 117                 .ke_dispname    = "aes256-cts-hmac-sha1-96",
 118                 .ke_enc_name    = "cbc(aes)",
 119                 .ke_hash_name   = "sha1",
 120                 .ke_hash_size   = 12,
 121                 .ke_conf_size   = 16,
 122                 .ke_hash_hmac   = 1,
 123         },
 124         [ENCTYPE_ARCFOUR_HMAC] = {              /* arcfour-hmac-md5 */
 125                 .ke_dispname    = "arcfour-hmac-md5",
 126                 .ke_enc_name    = "ecb(arc4)",
 127                 .ke_hash_name   = "md5",
 128                 .ke_hash_size   = 16,
 129                 .ke_conf_size   = 8,
 130                 .ke_hash_hmac   = 1,
 131         }
 132 };
 133
 134 static const char * enctype2str(__u32 enctype)
 135 {
 136         if (enctype < ARRAY_SIZE(enctypes) && enctypes[enctype].ke_dispname)
 137                 return enctypes[enctype].ke_dispname;
 138
 139         return "unknown";
 140 }
 141
 142 static
 143 int krb5_init_keys(struct krb5_ctx *kctx)
 144 {
 145         struct krb5_enctype *ke;
 146
 147         if (kctx->kc_enctype >= ARRAY_SIZE(enctypes) ||
 148             enctypes[kctx->kc_enctype].ke_hash_size == 0) {
 149                 CERROR("unsupported enctype %x\n", kctx->kc_enctype);
 150                 return -1;
 151         }
 152
 153         ke = &enctypes[kctx->kc_enctype];
 154
 155         /* tfm arc4 is stateful, user should alloc-use-free by his own */
 156         if (kctx->kc_enctype != ENCTYPE_ARCFOUR_HMAC &&
 157             gss_keyblock_init(&kctx->kc_keye, ke->ke_enc_name, ke->ke_enc_mode))
 158                 return -1;
 159
 160         /* tfm hmac is stateful, user should alloc-use-free by his own */
 161         if (ke->ke_hash_hmac == 0 &&
 162             gss_keyblock_init(&kctx->kc_keyi, ke->ke_enc_name, ke->ke_enc_mode))
 163                 return -1;
 164         if (ke->ke_hash_hmac == 0 &&
 165             gss_keyblock_init(&kctx->kc_keyc, ke->ke_enc_name, ke->ke_enc_mode))
 166                 return -1;
 167
 168         return 0;
 169 }
 170
 171 static
 172 void delete_context_kerberos(struct krb5_ctx *kctx)
 173 {
 174         rawobj_free(&kctx->kc_mech_used);
 175
 176         gss_keyblock_free(&kctx->kc_keye);
 177         gss_keyblock_free(&kctx->kc_keyi);
 178         gss_keyblock_free(&kctx->kc_keyc);
 179 }
 180
 181 static
 182 __u32 import_context_rfc1964(struct krb5_ctx *kctx, char *p, char *end)
 183 {
 184         unsigned int    tmp_uint, keysize;
 185
 186         /* seed_init flag */
 187         if (gss_get_bytes(&p, end, &tmp_uint, sizeof(tmp_uint)))
 188                 goto out_err;
 189         kctx->kc_seed_init = (tmp_uint != 0);
 190
 191         /* seed */
 192         if (gss_get_bytes(&p, end, kctx->kc_seed, sizeof(kctx->kc_seed)))
 193                 goto out_err;
 194
 195         /* sign/seal algorithm, not really used now */
 196         if (gss_get_bytes(&p, end, &tmp_uint, sizeof(tmp_uint)) ||
 197             gss_get_bytes(&p, end, &tmp_uint, sizeof(tmp_uint)))
 198                 goto out_err;
 199
 200         /* end time. While kc_endtime might be 64 bit the krb5 API
 201          * still uses 32 bits. To delay the 2038 bug see the incoming
 202          * value as a u32 which give us until 2106. See the link for details:
 203          *
 204          * http://web.mit.edu/kerberos/www/krb5-current/doc/appdev/y2038.html
 205          */
 206         if (gss_get_bytes(&p, end, &kctx->kc_endtime, sizeof(u32)))
 207                 goto out_err;
 208
 209         /* seq send */
 210         if (gss_get_bytes(&p, end, &tmp_uint, sizeof(tmp_uint)))
 211                 goto out_err;
 212         kctx->kc_seq_send = tmp_uint;
 213
 214         /* mech oid */
 215         if (gss_get_rawobj(&p, end, &kctx->kc_mech_used))
 216                 goto out_err;
 217
 218         /* old style enc/seq keys in format:
 219          *   - enctype (u32)
 220          *   - keysize (u32)
 221          *   - keydata
 222          * we decompose them to fit into the new context
 223          */
 224
 225         /* enc key */
 226         if (gss_get_bytes(&p, end, &kctx->kc_enctype, sizeof(kctx->kc_enctype)))
 227                 goto out_err;
 228
 229         if (gss_get_bytes(&p, end, &keysize, sizeof(keysize)))
 230                 goto out_err;
 231
 232         if (gss_get_keyblock(&p, end, &kctx->kc_keye, keysize))
 233                 goto out_err;
 234
 235         /* seq key */
 236         if (gss_get_bytes(&p, end, &tmp_uint, sizeof(tmp_uint)) ||
 237             tmp_uint != kctx->kc_enctype)
 238                 goto out_err;
 239
 240         if (gss_get_bytes(&p, end, &tmp_uint, sizeof(tmp_uint)) ||
 241             tmp_uint != keysize)
 242                 goto out_err;
 243
 244         if (gss_get_keyblock(&p, end, &kctx->kc_keyc, keysize))
 245                 goto out_err;
 246
 247         /* old style fallback */
 248         if (gss_keyblock_dup(&kctx->kc_keyi, &kctx->kc_keyc))
 249                 goto out_err;
 250
 251         if (p != end)
 252                 goto out_err;
 253
 254         CDEBUG(D_SEC, "successfully imported rfc1964 context\n");
 255         return 0;
 256 out_err:
 257         return GSS_S_FAILURE;
 258 }
 259
 260 /* Flags for version 2 context flags */
 261 #define KRB5_CTX_FLAG_INITIATOR         0x00000001
 262 #define KRB5_CTX_FLAG_CFX               0x00000002
 263 #define KRB5_CTX_FLAG_ACCEPTOR_SUBKEY   0x00000004
 264
 265 static
 266 __u32 import_context_rfc4121(struct krb5_ctx *kctx, char *p, char *end)
 267 {
 268         unsigned int    tmp_uint, keysize;
 269
 270         /* end time. While kc_endtime might be 64 bit the krb5 API
 271          * still uses 32 bits. To delay the 2038 bug see the incoming
 272          * value as a u32 which give us until 2106. See the link for details:
 273          *
 274          * http://web.mit.edu/kerberos/www/krb5-current/doc/appdev/y2038.html
 275          */
 276         if (gss_get_bytes(&p, end, &kctx->kc_endtime, sizeof(u32)))
 277                 goto out_err;
 278
 279         /* flags */
 280         if (gss_get_bytes(&p, end, &tmp_uint, sizeof(tmp_uint)))
 281                 goto out_err;
 282
 283         if (tmp_uint & KRB5_CTX_FLAG_INITIATOR)
 284                 kctx->kc_initiate = 1;
 285         if (tmp_uint & KRB5_CTX_FLAG_CFX)
 286                 kctx->kc_cfx = 1;
 287         if (tmp_uint & KRB5_CTX_FLAG_ACCEPTOR_SUBKEY)
 288                 kctx->kc_have_acceptor_subkey = 1;
 289
 290         /* seq send */
 291         if (gss_get_bytes(&p, end, &kctx->kc_seq_send,
 292             sizeof(kctx->kc_seq_send)))
 293                 goto out_err;
 294
 295         /* enctype */
 296         if (gss_get_bytes(&p, end, &kctx->kc_enctype, sizeof(kctx->kc_enctype)))
 297                 goto out_err;
 298
 299         /* size of each key */
 300         if (gss_get_bytes(&p, end, &keysize, sizeof(keysize)))
 301                 goto out_err;
 302
 303         /* number of keys - should always be 3 */
 304         if (gss_get_bytes(&p, end, &tmp_uint, sizeof(tmp_uint)))
 305                 goto out_err;
 306
 307         if (tmp_uint != 3) {
 308                 CERROR("Invalid number of keys: %u\n", tmp_uint);
 309                 goto out_err;
 310         }
 311
 312         /* ke */
 313         if (gss_get_keyblock(&p, end, &kctx->kc_keye, keysize))
 314                 goto out_err;
 315         /* ki */
 316         if (gss_get_keyblock(&p, end, &kctx->kc_keyi, keysize))
 317                 goto out_err;
 318         /* ki */
 319         if (gss_get_keyblock(&p, end, &kctx->kc_keyc, keysize))
 320                 goto out_err;
 321
 322         CDEBUG(D_SEC, "successfully imported v2 context\n");
 323         return 0;
 324 out_err:
 325         return GSS_S_FAILURE;
 326 }
 327
 328 /*
 329  * The whole purpose here is trying to keep user level gss context parsing
 330  * from nfs-utils unchanged as possible as we can, they are not quite mature
 331  * yet, and many stuff still not clear, like heimdal etc.
 332  */
 333 static
 334 __u32 gss_import_sec_context_kerberos(rawobj_t *inbuf,
 335                                       struct gss_ctx *gctx)
 336 {
 337         struct krb5_ctx *kctx;
 338         char *p = (char *)inbuf->data;
 339         char *end = (char *)(inbuf->data + inbuf->len);
 340         unsigned int tmp_uint, rc;
 341
 342         if (gss_get_bytes(&p, end, &tmp_uint, sizeof(tmp_uint))) {
 343                 CERROR("Fail to read version\n");
 344                 return GSS_S_FAILURE;
 345         }
 346
 347         /* only support 0, 1 for the moment */
 348         if (tmp_uint > 2) {
 349                 CERROR("Invalid version %u\n", tmp_uint);
 350                 return GSS_S_FAILURE;
 351         }
 352
 353         OBD_ALLOC_PTR(kctx);
 354         if (!kctx)
 355                 return GSS_S_FAILURE;
 356
 357         if (tmp_uint == 0 || tmp_uint == 1) {
 358                 kctx->kc_initiate = tmp_uint;
 359                 rc = import_context_rfc1964(kctx, p, end);
 360         } else {
 361                 rc = import_context_rfc4121(kctx, p, end);
 362         }
 363
 364         if (rc == 0)
 365                 rc = krb5_init_keys(kctx);
 366
 367         if (rc) {
 368                 delete_context_kerberos(kctx);
 369                 OBD_FREE_PTR(kctx);
 370
 371                 return GSS_S_FAILURE;
 372         }
 373
 374         gctx->internal_ctx_id = kctx;
 375         return GSS_S_COMPLETE;
 376 }
 377
 378 static
 379 __u32 gss_copy_reverse_context_kerberos(struct gss_ctx *gctx,
 380                                         struct gss_ctx *gctx_new)
 381 {
 382         struct krb5_ctx *kctx = gctx->internal_ctx_id;
 383         struct krb5_ctx *knew;
 384
 385         OBD_ALLOC_PTR(knew);
 386         if (!knew)
 387                 return GSS_S_FAILURE;
 388
 389         knew->kc_initiate = kctx->kc_initiate ? 0 : 1;
 390         knew->kc_cfx = kctx->kc_cfx;
 391         knew->kc_seed_init = kctx->kc_seed_init;
 392         knew->kc_have_acceptor_subkey = kctx->kc_have_acceptor_subkey;
 393         knew->kc_endtime = kctx->kc_endtime;
 394
 395         memcpy(knew->kc_seed, kctx->kc_seed, sizeof(kctx->kc_seed));
 396         knew->kc_seq_send = kctx->kc_seq_recv;
 397         knew->kc_seq_recv = kctx->kc_seq_send;
 398         knew->kc_enctype = kctx->kc_enctype;
 399
 400         if (rawobj_dup(&knew->kc_mech_used, &kctx->kc_mech_used))
 401                 goto out_err;
 402
 403         if (gss_keyblock_dup(&knew->kc_keye, &kctx->kc_keye))
 404                 goto out_err;
 405         if (gss_keyblock_dup(&knew->kc_keyi, &kctx->kc_keyi))
 406                 goto out_err;
 407         if (gss_keyblock_dup(&knew->kc_keyc, &kctx->kc_keyc))
 408                 goto out_err;
 409         if (krb5_init_keys(knew))
 410                 goto out_err;
 411
 412         gctx_new->internal_ctx_id = knew;
 413         CDEBUG(D_SEC, "successfully copied reverse context\n");
 414         return GSS_S_COMPLETE;
 415
 416 out_err:
 417         delete_context_kerberos(knew);
 418         OBD_FREE_PTR(knew);
 419         return GSS_S_FAILURE;
 420 }
 421
 422 static
 423 __u32 gss_inquire_context_kerberos(struct gss_ctx *gctx,
 424                                    time64_t *endtime)
 425 {
 426         struct krb5_ctx *kctx = gctx->internal_ctx_id;
 427
 428         *endtime = kctx->kc_endtime;
 429         return GSS_S_COMPLETE;
 430 }
 431
 432 static
 433 void gss_delete_sec_context_kerberos(void *internal_ctx)
 434 {
 435         struct krb5_ctx *kctx = internal_ctx;
 436
 437         delete_context_kerberos(kctx);
 438         OBD_FREE_PTR(kctx);
 439 }
 440
 441 /*
 442  * compute (keyed/keyless) checksum against the plain text which appended
 443  * with krb5 wire token header.
 444  */
 445 static
 446 __s32 krb5_make_checksum(__u32 enctype,
 447                          struct gss_keyblock *kb,
 448                          struct krb5_header *khdr,
 449                          int msgcnt, rawobj_t *msgs,
 450                          int iovcnt, struct bio_vec *iovs,
 451                          rawobj_t *cksum,
 452                          digest_hash hash_func)
 453 {
 454         struct krb5_enctype *ke = &enctypes[enctype];
 455         struct ahash_request *req = NULL;
 456         enum cfs_crypto_hash_alg hash_algo;
 457         rawobj_t hdr;
 458         int rc;
 459
 460         hash_algo = cfs_crypto_hash_alg(ke->ke_hash_name);
 461
 462         /* For the cbc(des) case we want md5 instead of hmac(md5) */
 463         if (strcmp(ke->ke_enc_name, "cbc(des)"))
 464                 req = cfs_crypto_hash_init(hash_algo, kb->kb_key.data,
 465                                            kb->kb_key.len);
 466         else
 467                 req = cfs_crypto_hash_init(hash_algo, NULL, 0);
 468         if (IS_ERR(req)) {
 469                 rc = PTR_ERR(req);
 470                 CERROR("failed to alloc hash %s : rc = %d\n",
 471                        ke->ke_hash_name, rc);
 472                 goto out_no_hash;
 473         }
 474
 475         cksum->len = cfs_crypto_hash_digestsize(hash_algo);
 476         OBD_ALLOC_LARGE(cksum->data, cksum->len);
 477         if (!cksum->data) {
 478                 cksum->len = 0;
 479                 rc = -ENOMEM;
 480                 goto out_free_hash;
 481         }
 482
 483         hdr.data = (__u8 *)khdr;
 484         hdr.len = sizeof(*khdr);
 485
 486         if (!hash_func) {
 487                 rc = -EPROTO;
 488                 CERROR("hash function for %s undefined\n",
 489                        ke->ke_hash_name);
 490                 goto out_free_hash;
 491         }
 492         rc = hash_func(req, &hdr, msgcnt, msgs, iovcnt, iovs);
 493         if (rc)
 494                 goto out_free_hash;
 495
 496         if (!ke->ke_hash_hmac) {
 497                 LASSERT(kb->kb_tfm);
 498
 499                 cfs_crypto_hash_final(req, cksum->data, &cksum->len);
 500                 rc = gss_crypt_generic(kb->kb_tfm, 0, NULL,
 501                                        cksum->data, cksum->data,
 502                                        cksum->len);
 503                 goto out_no_hash;
 504         }
 505
 506 out_free_hash:
 507         if (req)
 508                 cfs_crypto_hash_final(req, cksum->data, &cksum->len);
 509 out_no_hash:
 510         return rc ? GSS_S_FAILURE : GSS_S_COMPLETE;
 511 }
 512
 513 static void fill_krb5_header(struct krb5_ctx *kctx,
 514                              struct krb5_header *khdr,
 515                              int privacy)
 516 {
 517         unsigned char acceptor_flag;
 518
 519         acceptor_flag = kctx->kc_initiate ? 0 : FLAG_SENDER_IS_ACCEPTOR;
 520
 521         if (privacy) {
 522                 khdr->kh_tok_id = cpu_to_be16(KG_TOK_WRAP_MSG);
 523                 khdr->kh_flags = acceptor_flag | FLAG_WRAP_CONFIDENTIAL;
 524                 khdr->kh_ec = cpu_to_be16(0);
 525                 khdr->kh_rrc = cpu_to_be16(0);
 526         } else {
 527                 khdr->kh_tok_id = cpu_to_be16(KG_TOK_MIC_MSG);
 528                 khdr->kh_flags = acceptor_flag;
 529                 khdr->kh_ec = cpu_to_be16(0xffff);
 530                 khdr->kh_rrc = cpu_to_be16(0xffff);
 531         }
 532
 533         khdr->kh_filler = 0xff;
 534         spin_lock(&krb5_seq_lock);
 535         khdr->kh_seq = cpu_to_be64(kctx->kc_seq_send++);
 536         spin_unlock(&krb5_seq_lock);
 537 }
 538
 539 static __u32 verify_krb5_header(struct krb5_ctx *kctx,
 540                                 struct krb5_header *khdr,
 541                                 int privacy)
 542 {
 543         unsigned char acceptor_flag;
 544         __u16         tok_id, ec_rrc;
 545
 546         acceptor_flag = kctx->kc_initiate ? FLAG_SENDER_IS_ACCEPTOR : 0;
 547
 548         if (privacy) {
 549                 tok_id = KG_TOK_WRAP_MSG;
 550                 ec_rrc = 0x0;
 551         } else {
 552                 tok_id = KG_TOK_MIC_MSG;
 553                 ec_rrc = 0xffff;
 554         }
 555
 556         /* sanity checks */
 557         if (be16_to_cpu(khdr->kh_tok_id) != tok_id) {
 558                 CERROR("bad token id\n");
 559                 return GSS_S_DEFECTIVE_TOKEN;
 560         }
 561         if ((khdr->kh_flags & FLAG_SENDER_IS_ACCEPTOR) != acceptor_flag) {
 562                 CERROR("bad direction flag\n");
 563                 return GSS_S_BAD_SIG;
 564         }
 565         if (privacy && (khdr->kh_flags & FLAG_WRAP_CONFIDENTIAL) == 0) {
 566                 CERROR("missing confidential flag\n");
 567                 return GSS_S_BAD_SIG;
 568         }
 569         if (khdr->kh_filler != 0xff) {
 570                 CERROR("bad filler\n");
 571                 return GSS_S_DEFECTIVE_TOKEN;
 572         }
 573         if (be16_to_cpu(khdr->kh_ec) != ec_rrc ||
 574             be16_to_cpu(khdr->kh_rrc) != ec_rrc) {
 575                 CERROR("bad EC or RRC\n");
 576                 return GSS_S_DEFECTIVE_TOKEN;
 577         }
 578         return GSS_S_COMPLETE;
 579 }
 580
 581 static
 582 __u32 gss_get_mic_kerberos(struct gss_ctx *gctx,
 583                            int msgcnt,
 584                            rawobj_t *msgs,
 585                            int iovcnt,
 586                            struct bio_vec *iovs,
 587                            rawobj_t *token)
 588 {
 589         struct krb5_ctx     *kctx = gctx->internal_ctx_id;
 590         struct krb5_enctype *ke = &enctypes[kctx->kc_enctype];
 591         struct krb5_header  *khdr;
 592         rawobj_t cksum = RAWOBJ_EMPTY;
 593         u32 major;
 594
 595         /* fill krb5 header */
 596         LASSERT(token->len >= sizeof(*khdr));
 597         khdr = (struct krb5_header *)token->data;
 598         fill_krb5_header(kctx, khdr, 0);
 599
 600         /* checksum */
 601         if (krb5_make_checksum(kctx->kc_enctype, &kctx->kc_keyc, khdr,
 602                                msgcnt, msgs, iovcnt, iovs, &cksum,
 603                                gctx->hash_func))
 604                 GOTO(out_free_cksum, major = GSS_S_FAILURE);
 605
 606         LASSERT(cksum.len >= ke->ke_hash_size);
 607         LASSERT(token->len >= sizeof(*khdr) + ke->ke_hash_size);
 608         memcpy(khdr + 1, cksum.data + cksum.len - ke->ke_hash_size,
 609                ke->ke_hash_size);
 610
 611         token->len = sizeof(*khdr) + ke->ke_hash_size;
 612         major = GSS_S_COMPLETE;
 613 out_free_cksum:
 614         rawobj_free(&cksum);
 615         return major;
 616 }
 617
 618 static
 619 __u32 gss_verify_mic_kerberos(struct gss_ctx *gctx,
 620                               int msgcnt,
 621                               rawobj_t *msgs,
 622                               int iovcnt,
 623                               struct bio_vec *iovs,
 624                               rawobj_t *token)
 625 {
 626         struct krb5_ctx *kctx = gctx->internal_ctx_id;
 627         struct krb5_enctype *ke = &enctypes[kctx->kc_enctype];
 628         struct krb5_header *khdr;
 629         rawobj_t cksum = RAWOBJ_EMPTY;
 630         u32 major;
 631
 632         if (token->len < sizeof(*khdr)) {
 633                 CERROR("short signature: %u\n", token->len);
 634                 return GSS_S_DEFECTIVE_TOKEN;
 635         }
 636
 637         khdr = (struct krb5_header *)token->data;
 638
 639         major = verify_krb5_header(kctx, khdr, 0);
 640         if (major != GSS_S_COMPLETE) {
 641                 CERROR("bad krb5 header\n");
 642                 goto out;
 643         }
 644
 645         if (token->len < sizeof(*khdr) + ke->ke_hash_size) {
 646                 CERROR("short signature: %u, require %d\n",
 647                        token->len, (int) sizeof(*khdr) + ke->ke_hash_size);
 648                 GOTO(out, major = GSS_S_FAILURE);
 649         }
 650
 651         if (krb5_make_checksum(kctx->kc_enctype, &kctx->kc_keyc,
 652                                khdr, msgcnt, msgs, iovcnt, iovs, &cksum,
 653                                gctx->hash_func))
 654                 GOTO(out_free_cksum, major = GSS_S_FAILURE);
 655
 656         LASSERT(cksum.len >= ke->ke_hash_size);
 657         if (memcmp(khdr + 1, cksum.data + cksum.len - ke->ke_hash_size,
 658                    ke->ke_hash_size)) {
 659                 CERROR("checksum mismatch\n");
 660                 GOTO(out_free_cksum, major = GSS_S_BAD_SIG);
 661         }
 662         major = GSS_S_COMPLETE;
 663 out_free_cksum:
 664         rawobj_free(&cksum);
 665 out:
 666         return major;
 667 }
 668
 669 /*
 670  * if adj_nob != 0, we adjust desc->bd_nob to the actual cipher text size.
 671  */
 672 static
 673 int krb5_encrypt_bulk(struct crypto_blkcipher *tfm,
 674                       struct krb5_header *khdr,
 675                       char *confounder,
 676                       struct ptlrpc_bulk_desc *desc,
 677                       rawobj_t *cipher,
 678                       int adj_nob)
 679 {
 680         struct blkcipher_desc   ciph_desc;
 681         __u8                    local_iv[16] = {0};
 682         struct scatterlist      src, dst;
 683         struct sg_table         sg_src, sg_dst;
 684         int                     blocksize, i, rc, nob = 0;
 685
 686         LASSERT(desc->bd_iov_count);
 687         LASSERT(desc->bd_enc_vec);
 688
 689         blocksize = crypto_blkcipher_blocksize(tfm);
 690         LASSERT(blocksize > 1);
 691         LASSERT(cipher->len == blocksize + sizeof(*khdr));
 692
 693         ciph_desc.tfm  = tfm;
 694         ciph_desc.info = local_iv;
 695         ciph_desc.flags = 0;
 696
 697         /* encrypt confounder */
 698         rc = gss_setup_sgtable(&sg_src, &src, confounder, blocksize);
 699         if (rc != 0)
 700                 return rc;
 701
 702         rc = gss_setup_sgtable(&sg_dst, &dst, cipher->data, blocksize);
 703         if (rc != 0) {
 704                 gss_teardown_sgtable(&sg_src);
 705                 return rc;
 706         }
 707
 708         rc = crypto_blkcipher_encrypt_iv(&ciph_desc, sg_dst.sgl,
 709                                          sg_src.sgl, blocksize);
 710
 711         gss_teardown_sgtable(&sg_dst);
 712         gss_teardown_sgtable(&sg_src);
 713
 714         if (rc) {
 715                 CERROR("error to encrypt confounder: %d\n", rc);
 716                 return rc;
 717         }
 718
 719         /* encrypt clear pages */
 720         for (i = 0; i < desc->bd_iov_count; i++) {
 721                 sg_init_table(&src, 1);
 722                 sg_set_page(&src, desc->bd_vec[i].bv_page,
 723                             (desc->bd_vec[i].bv_len +
 724                                 blocksize - 1) &
 725                             (~(blocksize - 1)),
 726                             desc->bd_vec[i].bv_offset);
 727                 if (adj_nob)
 728                         nob += src.length;
 729                 sg_init_table(&dst, 1);
 730                 sg_set_page(&dst, desc->bd_enc_vec[i].bv_page,
 731                             src.length, src.offset);
 732
 733                 desc->bd_enc_vec[i].bv_offset = dst.offset;
 734                 desc->bd_enc_vec[i].bv_len = dst.length;
 735
 736                 rc = crypto_blkcipher_encrypt_iv(&ciph_desc, &dst, &src,
 737                                                     src.length);
 738                 if (rc) {
 739                         CERROR("error to encrypt page: %d\n", rc);
 740                         return rc;
 741                 }
 742         }
 743
 744         /* encrypt krb5 header */
 745         rc = gss_setup_sgtable(&sg_src, &src, khdr, sizeof(*khdr));
 746         if (rc != 0)
 747                 return rc;
 748
 749         rc = gss_setup_sgtable(&sg_dst, &dst, cipher->data + blocksize,
 750                            sizeof(*khdr));
 751         if (rc != 0) {
 752                 gss_teardown_sgtable(&sg_src);
 753                 return rc;
 754         }
 755
 756         rc = crypto_blkcipher_encrypt_iv(&ciph_desc, sg_dst.sgl, sg_src.sgl,
 757                                          sizeof(*khdr));
 758
 759         gss_teardown_sgtable(&sg_dst);
 760         gss_teardown_sgtable(&sg_src);
 761
 762         if (rc) {
 763                 CERROR("error to encrypt krb5 header: %d\n", rc);
 764                 return rc;
 765         }
 766
 767         if (adj_nob)
 768                 desc->bd_nob = nob;
 769
 770         return 0;
 771 }
 772
 773 /*
 774  * desc->bd_nob_transferred is the size of cipher text received.
 775  * desc->bd_nob is the target size of plain text supposed to be.
 776  *
 777  * if adj_nob != 0, we adjust each page's bv_len to the actual
 778  * plain text size.
 779  * - for client read: we don't know data size for each page, so
 780  *   bd_iov[]->bv_len is set to PAGE_SIZE, but actual data received might
 781  *   be smaller, so we need to adjust it according to
 782  *   bd_u.bd_kiov.bd_enc_vec[]->bv_len.
 783  *   this means we DO NOT support the situation that server send an odd size
 784  *   data in a page which is not the last one.
 785  * - for server write: we knows exactly data size for each page being expected,
 786  *   thus bv_len is accurate already, so we should not adjust it at all.
 787  *   and bd_u.bd_kiov.bd_enc_vec[]->bv_len should be
 788  *   round_up(bd_iov[]->bv_len) which
 789  *   should have been done by prep_bulk().
 790  */
 791 static
 792 int krb5_decrypt_bulk(struct crypto_blkcipher *tfm,
 793                       struct krb5_header *khdr,
 794                       struct ptlrpc_bulk_desc *desc,
 795                       rawobj_t *cipher,
 796                       rawobj_t *plain,
 797                       int adj_nob)
 798 {
 799         struct blkcipher_desc   ciph_desc;
 800         __u8                    local_iv[16] = {0};
 801         struct scatterlist      src, dst;
 802         struct sg_table         sg_src, sg_dst;
 803         int                     ct_nob = 0, pt_nob = 0;
 804         int                     blocksize, i, rc;
 805
 806         LASSERT(desc->bd_iov_count);
 807         LASSERT(desc->bd_enc_vec);
 808         LASSERT(desc->bd_nob_transferred);
 809
 810         blocksize = crypto_blkcipher_blocksize(tfm);
 811         LASSERT(blocksize > 1);
 812         LASSERT(cipher->len == blocksize + sizeof(*khdr));
 813
 814         ciph_desc.tfm  = tfm;
 815         ciph_desc.info = local_iv;
 816         ciph_desc.flags = 0;
 817
 818         if (desc->bd_nob_transferred % blocksize) {
 819                 CERROR("odd transferred nob: %d\n", desc->bd_nob_transferred);
 820                 return -EPROTO;
 821         }
 822
 823         /* decrypt head (confounder) */
 824         rc = gss_setup_sgtable(&sg_src, &src, cipher->data, blocksize);
 825         if (rc != 0)
 826                 return rc;
 827
 828         rc = gss_setup_sgtable(&sg_dst, &dst, plain->data, blocksize);
 829         if (rc != 0) {
 830                 gss_teardown_sgtable(&sg_src);
 831                 return rc;
 832         }
 833
 834         rc = crypto_blkcipher_decrypt_iv(&ciph_desc, sg_dst.sgl,
 835                                          sg_src.sgl, blocksize);
 836
 837         gss_teardown_sgtable(&sg_dst);
 838         gss_teardown_sgtable(&sg_src);
 839
 840         if (rc) {
 841                 CERROR("error to decrypt confounder: %d\n", rc);
 842                 return rc;
 843         }
 844
 845         for (i = 0; i < desc->bd_iov_count && ct_nob < desc->bd_nob_transferred;
 846              i++) {
 847                 if (desc->bd_enc_vec[i].bv_offset % blocksize
 848                     != 0 ||
 849                     desc->bd_enc_vec[i].bv_len % blocksize
 850                     != 0) {
 851                         CERROR("page %d: odd offset %u len %u, blocksize %d\n",
 852                                i, desc->bd_enc_vec[i].bv_offset,
 853                                desc->bd_enc_vec[i].bv_len,
 854                                blocksize);
 855                         return -EFAULT;
 856                 }
 857
 858                 if (adj_nob) {
 859                         if (ct_nob + desc->bd_enc_vec[i].bv_len >
 860                             desc->bd_nob_transferred)
 861                                 desc->bd_enc_vec[i].bv_len =
 862                                         desc->bd_nob_transferred - ct_nob;
 863
 864                         desc->bd_vec[i].bv_len =
 865                           desc->bd_enc_vec[i].bv_len;
 866                         if (pt_nob + desc->bd_enc_vec[i].bv_len >
 867                             desc->bd_nob)
 868                                 desc->bd_vec[i].bv_len =
 869                                   desc->bd_nob - pt_nob;
 870                 } else {
 871                         /* this should be guaranteed by LNET */
 872                         LASSERT(ct_nob + desc->bd_enc_vec[i].
 873                                 bv_len <=
 874                                 desc->bd_nob_transferred);
 875                         LASSERT(desc->bd_vec[i].bv_len <=
 876                                 desc->bd_enc_vec[i].bv_len);
 877                 }
 878
 879                 if (desc->bd_enc_vec[i].bv_len == 0)
 880                         continue;
 881
 882                 sg_init_table(&src, 1);
 883                 sg_set_page(&src, desc->bd_enc_vec[i].bv_page,
 884                             desc->bd_enc_vec[i].bv_len,
 885                             desc->bd_enc_vec[i].bv_offset);
 886                 dst = src;
 887                 if (desc->bd_vec[i].bv_len % blocksize == 0)
 888                         sg_assign_page(&dst,
 889                                        desc->bd_vec[i].bv_page);
 890
 891                 rc = crypto_blkcipher_decrypt_iv(&ciph_desc, &dst, &src,
 892                                                  src.length);
 893                 if (rc) {
 894                         CERROR("error to decrypt page: %d\n", rc);
 895                         return rc;
 896                 }
 897
 898                 if (desc->bd_vec[i].bv_len % blocksize != 0) {
 899                         memcpy(page_address(desc->bd_vec[i].bv_page) +
 900                                desc->bd_vec[i].bv_offset,
 901                                page_address(desc->bd_enc_vec[i].
 902                                             bv_page) +
 903                                desc->bd_vec[i].bv_offset,
 904                                desc->bd_vec[i].bv_len);
 905                 }
 906
 907                 ct_nob += desc->bd_enc_vec[i].bv_len;
 908                 pt_nob += desc->bd_vec[i].bv_len;
 909         }
 910
 911         if (unlikely(ct_nob != desc->bd_nob_transferred)) {
 912                 CERROR("%d cipher text transferred but only %d decrypted\n",
 913                        desc->bd_nob_transferred, ct_nob);
 914                 return -EFAULT;
 915         }
 916
 917         if (unlikely(!adj_nob && pt_nob != desc->bd_nob)) {
 918                 CERROR("%d plain text expected but only %d received\n",
 919                        desc->bd_nob, pt_nob);
 920                 return -EFAULT;
 921         }
 922
 923         /* if needed, clear up the rest unused iovs */
 924         if (adj_nob)
 925                 while (i < desc->bd_iov_count)
 926                         desc->bd_vec[i++].bv_len = 0;
 927
 928         /* decrypt tail (krb5 header) */
 929         rc = gss_setup_sgtable(&sg_src, &src, cipher->data + blocksize,
 930                                sizeof(*khdr));
 931         if (rc != 0)
 932                 return rc;
 933
 934         rc = gss_setup_sgtable(&sg_dst, &dst, cipher->data + blocksize,
 935                                sizeof(*khdr));
 936         if (rc != 0) {
 937                 gss_teardown_sgtable(&sg_src);
 938                 return rc;
 939         }
 940
 941         rc = crypto_blkcipher_decrypt_iv(&ciph_desc, sg_dst.sgl, sg_src.sgl,
 942                                          sizeof(*khdr));
 943
 944         gss_teardown_sgtable(&sg_src);
 945         gss_teardown_sgtable(&sg_dst);
 946
 947         if (rc) {
 948                 CERROR("error to decrypt tail: %d\n", rc);
 949                 return rc;
 950         }
 951
 952         if (memcmp(cipher->data + blocksize, khdr, sizeof(*khdr))) {
 953                 CERROR("krb5 header doesn't match\n");
 954                 return -EACCES;
 955         }
 956
 957         return 0;
 958 }
 959
 960 static
 961 __u32 gss_wrap_kerberos(struct gss_ctx *gctx,
 962                         rawobj_t *gsshdr,
 963                         rawobj_t *msg,
 964                         int msg_buflen,
 965                         rawobj_t *token)
 966 {
 967         struct krb5_ctx     *kctx = gctx->internal_ctx_id;
 968         struct krb5_enctype *ke = &enctypes[kctx->kc_enctype];
 969         struct krb5_header  *khdr;
 970         int                  blocksize;
 971         rawobj_t             cksum = RAWOBJ_EMPTY;
 972         rawobj_t             data_desc[3], cipher;
 973         __u8                 conf[GSS_MAX_CIPHER_BLOCK];
 974         __u8                 local_iv[16] = {0};
 975         u32 major;
 976         int                  rc = 0;
 977
 978         LASSERT(ke);
 979         LASSERT(ke->ke_conf_size <= GSS_MAX_CIPHER_BLOCK);
 980         LASSERT(kctx->kc_keye.kb_tfm == NULL ||
 981                 ke->ke_conf_size >=
 982                 crypto_blkcipher_blocksize(kctx->kc_keye.kb_tfm));
 983
 984         /*
 985          * final token format:
 986          * ---------------------------------------------------
 987          * | krb5 header | cipher text | checksum (16 bytes) |
 988          * ---------------------------------------------------
 989          */
 990
 991         /* fill krb5 header */
 992         LASSERT(token->len >= sizeof(*khdr));
 993         khdr = (struct krb5_header *)token->data;
 994         fill_krb5_header(kctx, khdr, 1);
 995
 996         /* generate confounder */
 997         get_random_bytes(conf, ke->ke_conf_size);
 998
 999         /* get encryption blocksize. note kc_keye might not associated with
1000          * a tfm, currently only for arcfour-hmac */
1001         if (kctx->kc_enctype == ENCTYPE_ARCFOUR_HMAC) {
1002                 LASSERT(kctx->kc_keye.kb_tfm == NULL);
1003                 blocksize = 1;
1004         } else {
1005                 LASSERT(kctx->kc_keye.kb_tfm);
1006                 blocksize = crypto_blkcipher_blocksize(kctx->kc_keye.kb_tfm);
1007         }
1008         LASSERT(blocksize <= ke->ke_conf_size);
1009
1010         /* padding the message */
1011         if (gss_add_padding(msg, msg_buflen, blocksize))
1012                 return GSS_S_FAILURE;
1013
1014         /*
1015          * clear text layout for checksum:
1016          * ------------------------------------------------------
1017          * | confounder | gss header | clear msgs | krb5 header |
1018          * ------------------------------------------------------
1019          */
1020         data_desc[0].data = conf;
1021         data_desc[0].len = ke->ke_conf_size;
1022         data_desc[1].data = gsshdr->data;
1023         data_desc[1].len = gsshdr->len;
1024         data_desc[2].data = msg->data;
1025         data_desc[2].len = msg->len;
1026
1027         /* compute checksum */
1028         if (krb5_make_checksum(kctx->kc_enctype, &kctx->kc_keyi,
1029                                khdr, 3, data_desc, 0, NULL, &cksum,
1030                                gctx->hash_func))
1031                 GOTO(out_free_cksum, major = GSS_S_FAILURE);
1032         LASSERT(cksum.len >= ke->ke_hash_size);
1033
1034         /*
1035          * clear text layout for encryption:
1036          * -----------------------------------------
1037          * | confounder | clear msgs | krb5 header |
1038          * -----------------------------------------
1039          */
1040         data_desc[0].data = conf;
1041         data_desc[0].len = ke->ke_conf_size;
1042         data_desc[1].data = msg->data;
1043         data_desc[1].len = msg->len;
1044         data_desc[2].data = (__u8 *) khdr;
1045         data_desc[2].len = sizeof(*khdr);
1046
1047         /* cipher text will be directly inplace */
1048         cipher.data = (__u8 *)(khdr + 1);
1049         cipher.len = token->len - sizeof(*khdr);
1050         LASSERT(cipher.len >= ke->ke_conf_size + msg->len + sizeof(*khdr));
1051
1052         if (kctx->kc_enctype == ENCTYPE_ARCFOUR_HMAC) {
1053                 rawobj_t arc4_keye = RAWOBJ_EMPTY;
1054                 struct crypto_blkcipher *arc4_tfm;
1055
1056                 if (krb5_make_checksum(ENCTYPE_ARCFOUR_HMAC, &kctx->kc_keyi,
1057                                        NULL, 1, &cksum, 0, NULL, &arc4_keye,
1058                                        gctx->hash_func)) {
1059                         CERROR("failed to obtain arc4 enc key\n");
1060                         GOTO(arc4_out_key, rc = -EACCES);
1061                 }
1062
1063                 arc4_tfm = crypto_alloc_blkcipher("ecb(arc4)", 0, 0);
1064                 if (IS_ERR(arc4_tfm)) {
1065                         CERROR("failed to alloc tfm arc4 in ECB mode\n");
1066                         GOTO(arc4_out_key, rc = -EACCES);
1067                 }
1068
1069                 if (crypto_blkcipher_setkey(arc4_tfm, arc4_keye.data,
1070                                             arc4_keye.len)) {
1071                         CERROR("failed to set arc4 key, len %d\n",
1072                                arc4_keye.len);
1073                         GOTO(arc4_out_tfm, rc = -EACCES);
1074                 }
1075
1076                 rc = gss_crypt_rawobjs(arc4_tfm, NULL, 3, data_desc,
1077                                        &cipher, 1);
1078 arc4_out_tfm:
1079                 crypto_free_blkcipher(arc4_tfm);
1080 arc4_out_key:
1081                 rawobj_free(&arc4_keye);
1082         } else {
1083                 rc = gss_crypt_rawobjs(kctx->kc_keye.kb_tfm, local_iv, 3,
1084                                        data_desc, &cipher, 1);
1085         }
1086
1087         if (rc)
1088                 GOTO(out_free_cksum, major = GSS_S_FAILURE);
1089
1090         /* fill in checksum */
1091         LASSERT(token->len >= sizeof(*khdr) + cipher.len + ke->ke_hash_size);
1092         memcpy((char *)(khdr + 1) + cipher.len,
1093                cksum.data + cksum.len - ke->ke_hash_size,
1094                ke->ke_hash_size);
1095
1096         /* final token length */
1097         token->len = sizeof(*khdr) + cipher.len + ke->ke_hash_size;
1098         major = GSS_S_COMPLETE;
1099 out_free_cksum:
1100         rawobj_free(&cksum);
1101         return major;
1102 }
1103
1104 static
1105 __u32 gss_prep_bulk_kerberos(struct gss_ctx *gctx,
1106                              struct ptlrpc_bulk_desc *desc)
1107 {
1108         struct krb5_ctx     *kctx = gctx->internal_ctx_id;
1109         int                  blocksize, i;
1110
1111         LASSERT(desc->bd_iov_count);
1112         LASSERT(desc->bd_enc_vec);
1113         LASSERT(kctx->kc_keye.kb_tfm);
1114
1115         blocksize = crypto_blkcipher_blocksize(kctx->kc_keye.kb_tfm);
1116
1117         for (i = 0; i < desc->bd_iov_count; i++) {
1118                 LASSERT(desc->bd_enc_vec[i].bv_page);
1119                 /*
1120                  * offset should always start at page boundary of either
1121                  * client or server side.
1122                  */
1123                 if (desc->bd_vec[i].bv_offset & blocksize) {
1124                         CERROR("odd offset %d in page %d\n",
1125                                desc->bd_vec[i].bv_offset, i);
1126                         return GSS_S_FAILURE;
1127                 }
1128
1129                 desc->bd_enc_vec[i].bv_offset =
1130                         desc->bd_vec[i].bv_offset;
1131                 desc->bd_enc_vec[i].bv_len =
1132                         (desc->bd_vec[i].bv_len +
1133                          blocksize - 1) & (~(blocksize - 1));
1134         }
1135
1136         return GSS_S_COMPLETE;
1137 }
1138
1139 static
1140 __u32 gss_wrap_bulk_kerberos(struct gss_ctx *gctx,
1141                              struct ptlrpc_bulk_desc *desc,
1142                              rawobj_t *token, int adj_nob)
1143 {
1144         struct krb5_ctx     *kctx = gctx->internal_ctx_id;
1145         struct krb5_enctype *ke = &enctypes[kctx->kc_enctype];
1146         struct krb5_header  *khdr;
1147         int                  blocksize;
1148         rawobj_t             cksum = RAWOBJ_EMPTY;
1149         rawobj_t             data_desc[1], cipher;
1150         __u8                 conf[GSS_MAX_CIPHER_BLOCK];
1151         int rc = 0;
1152         u32 major;
1153
1154         LASSERT(ke);
1155         LASSERT(ke->ke_conf_size <= GSS_MAX_CIPHER_BLOCK);
1156
1157         /*
1158          * final token format:
1159          * --------------------------------------------------
1160          * | krb5 header | head/tail cipher text | checksum |
1161          * --------------------------------------------------
1162          */
1163
1164         /* fill krb5 header */
1165         LASSERT(token->len >= sizeof(*khdr));
1166         khdr = (struct krb5_header *)token->data;
1167         fill_krb5_header(kctx, khdr, 1);
1168
1169         /* generate confounder */
1170         get_random_bytes(conf, ke->ke_conf_size);
1171
1172         /* get encryption blocksize. note kc_keye might not associated with
1173          * a tfm, currently only for arcfour-hmac */
1174         if (kctx->kc_enctype == ENCTYPE_ARCFOUR_HMAC) {
1175                 LASSERT(kctx->kc_keye.kb_tfm == NULL);
1176                 blocksize = 1;
1177         } else {
1178                 LASSERT(kctx->kc_keye.kb_tfm);
1179                 blocksize = crypto_blkcipher_blocksize(kctx->kc_keye.kb_tfm);
1180         }
1181
1182         /*
1183          * we assume the size of krb5_header (16 bytes) must be n * blocksize.
1184          * the bulk token size would be exactly (sizeof(krb5_header) +
1185          * blocksize + sizeof(krb5_header) + hashsize)
1186          */
1187         LASSERT(blocksize <= ke->ke_conf_size);
1188         LASSERT(sizeof(*khdr) >= blocksize && sizeof(*khdr) % blocksize == 0);
1189         LASSERT(token->len >= sizeof(*khdr) + blocksize + sizeof(*khdr) + 16);
1190
1191         /*
1192          * clear text layout for checksum:
1193          * ------------------------------------------
1194          * | confounder | clear pages | krb5 header |
1195          * ------------------------------------------
1196          */
1197         data_desc[0].data = conf;
1198         data_desc[0].len = ke->ke_conf_size;
1199
1200         /* compute checksum */
1201         if (krb5_make_checksum(kctx->kc_enctype, &kctx->kc_keyi,
1202                                khdr, 1, data_desc,
1203                                desc->bd_iov_count, desc->bd_vec,
1204                                &cksum, gctx->hash_func))
1205                 GOTO(out_free_cksum, major = GSS_S_FAILURE);
1206         LASSERT(cksum.len >= ke->ke_hash_size);
1207
1208         /*
1209          * clear text layout for encryption:
1210          * ------------------------------------------
1211          * | confounder | clear pages | krb5 header |
1212          * ------------------------------------------
1213          *        |              |             |
1214          *        ----------  (cipher pages)   |
1215          * result token:   |                   |
1216          * -------------------------------------------
1217          * | krb5 header | cipher text | cipher text |
1218          * -------------------------------------------
1219          */
1220         data_desc[0].data = conf;
1221         data_desc[0].len = ke->ke_conf_size;
1222
1223         cipher.data = (__u8 *)(khdr + 1);
1224         cipher.len = blocksize + sizeof(*khdr);
1225
1226         if (kctx->kc_enctype == ENCTYPE_ARCFOUR_HMAC) {
1227                 LBUG();
1228                 rc = 0;
1229         } else {
1230                 rc = krb5_encrypt_bulk(kctx->kc_keye.kb_tfm, khdr,
1231                                        conf, desc, &cipher, adj_nob);
1232         }
1233         if (rc)
1234                 GOTO(out_free_cksum, major = GSS_S_FAILURE);
1235
1236         /* fill in checksum */
1237         LASSERT(token->len >= sizeof(*khdr) + cipher.len + ke->ke_hash_size);
1238         memcpy((char *)(khdr + 1) + cipher.len,
1239                cksum.data + cksum.len - ke->ke_hash_size,
1240                ke->ke_hash_size);
1241
1242         /* final token length */
1243         token->len = sizeof(*khdr) + cipher.len + ke->ke_hash_size;
1244         major = GSS_S_COMPLETE;
1245 out_free_cksum:
1246         rawobj_free(&cksum);
1247         return major;
1248 }
1249
1250 static
1251 __u32 gss_unwrap_kerberos(struct gss_ctx  *gctx,
1252                           rawobj_t        *gsshdr,
1253                           rawobj_t        *token,
1254                           rawobj_t        *msg)
1255 {
1256         struct krb5_ctx     *kctx = gctx->internal_ctx_id;
1257         struct krb5_enctype *ke = &enctypes[kctx->kc_enctype];
1258         struct krb5_header  *khdr;
1259         unsigned char       *tmpbuf;
1260         int                  blocksize, bodysize;
1261         rawobj_t             cksum = RAWOBJ_EMPTY;
1262         rawobj_t             cipher_in, plain_out;
1263         rawobj_t             hash_objs[3];
1264         int                  rc = 0;
1265         __u32                major;
1266         __u8                 local_iv[16] = {0};
1267
1268         LASSERT(ke);
1269
1270         if (token->len < sizeof(*khdr)) {
1271                 CERROR("short signature: %u\n", token->len);
1272                 return GSS_S_DEFECTIVE_TOKEN;
1273         }
1274
1275         khdr = (struct krb5_header *)token->data;
1276
1277         major = verify_krb5_header(kctx, khdr, 1);
1278         if (major != GSS_S_COMPLETE) {
1279                 CERROR("bad krb5 header\n");
1280                 return major;
1281         }
1282
1283         /* block size */
1284         if (kctx->kc_enctype == ENCTYPE_ARCFOUR_HMAC) {
1285                 LASSERT(kctx->kc_keye.kb_tfm == NULL);
1286                 blocksize = 1;
1287         } else {
1288                 LASSERT(kctx->kc_keye.kb_tfm);
1289                 blocksize = crypto_blkcipher_blocksize(kctx->kc_keye.kb_tfm);
1290         }
1291
1292         /* expected token layout:
1293          * ----------------------------------------
1294          * | krb5 header | cipher text | checksum |
1295          * ----------------------------------------
1296          */
1297         bodysize = token->len - sizeof(*khdr) - ke->ke_hash_size;
1298
1299         if (bodysize % blocksize) {
1300                 CERROR("odd bodysize %d\n", bodysize);
1301                 return GSS_S_DEFECTIVE_TOKEN;
1302         }
1303
1304         if (bodysize <= ke->ke_conf_size + sizeof(*khdr)) {
1305                 CERROR("incomplete token: bodysize %d\n", bodysize);
1306                 return GSS_S_DEFECTIVE_TOKEN;
1307         }
1308
1309         if (msg->len < bodysize - ke->ke_conf_size - sizeof(*khdr)) {
1310                 CERROR("buffer too small: %u, require %d\n",
1311                        msg->len, bodysize - ke->ke_conf_size);
1312                 return GSS_S_FAILURE;
1313         }
1314
1315         /* decrypting */
1316         OBD_ALLOC_LARGE(tmpbuf, bodysize);
1317         if (!tmpbuf)
1318                 return GSS_S_FAILURE;
1319
1320         major = GSS_S_FAILURE;
1321
1322         cipher_in.data = (__u8 *)(khdr + 1);
1323         cipher_in.len = bodysize;
1324         plain_out.data = tmpbuf;
1325         plain_out.len = bodysize;
1326
1327         if (kctx->kc_enctype == ENCTYPE_ARCFOUR_HMAC) {
1328                 rawobj_t                 arc4_keye;
1329                 struct crypto_blkcipher *arc4_tfm;
1330
1331                 cksum.data = token->data + token->len - ke->ke_hash_size;
1332                 cksum.len = ke->ke_hash_size;
1333
1334                 if (krb5_make_checksum(ENCTYPE_ARCFOUR_HMAC, &kctx->kc_keyi,
1335                                        NULL, 1, &cksum, 0, NULL, &arc4_keye,
1336                                        gctx->hash_func)) {
1337                         CERROR("failed to obtain arc4 enc key\n");
1338                         GOTO(arc4_out, rc = -EACCES);
1339                 }
1340
1341                 arc4_tfm = crypto_alloc_blkcipher("ecb(arc4)", 0, 0);
1342                 if (IS_ERR(arc4_tfm)) {
1343                         CERROR("failed to alloc tfm arc4 in ECB mode\n");
1344                         GOTO(arc4_out_key, rc = -EACCES);
1345                 }
1346
1347                 if (crypto_blkcipher_setkey(arc4_tfm,
1348                                             arc4_keye.data, arc4_keye.len)) {
1349                         CERROR("failed to set arc4 key, len %d\n",
1350                                arc4_keye.len);
1351                         GOTO(arc4_out_tfm, rc = -EACCES);
1352                 }
1353
1354                 rc = gss_crypt_rawobjs(arc4_tfm, NULL, 1, &cipher_in,
1355                                        &plain_out, 0);
1356 arc4_out_tfm:
1357                 crypto_free_blkcipher(arc4_tfm);
1358 arc4_out_key:
1359                 rawobj_free(&arc4_keye);
1360 arc4_out:
1361                 cksum = RAWOBJ_EMPTY;
1362         } else {
1363                 rc = gss_crypt_rawobjs(kctx->kc_keye.kb_tfm, local_iv, 1,
1364                                        &cipher_in, &plain_out, 0);
1365         }
1366
1367         if (rc != 0) {
1368                 CERROR("error decrypt\n");
1369                 goto out_free;
1370         }
1371         LASSERT(plain_out.len == bodysize);
1372
1373         /* expected clear text layout:
1374          * -----------------------------------------
1375          * | confounder | clear msgs | krb5 header |
1376          * -----------------------------------------
1377          */
1378
1379         /* verify krb5 header in token is not modified */
1380         if (memcmp(khdr, plain_out.data + plain_out.len - sizeof(*khdr),
1381                    sizeof(*khdr))) {
1382                 CERROR("decrypted krb5 header mismatch\n");
1383                 goto out_free;
1384         }
1385
1386         /* verify checksum, compose clear text as layout:
1387          * ------------------------------------------------------
1388          * | confounder | gss header | clear msgs | krb5 header |
1389          * ------------------------------------------------------
1390          */
1391         hash_objs[0].len = ke->ke_conf_size;
1392         hash_objs[0].data = plain_out.data;
1393         hash_objs[1].len = gsshdr->len;
1394         hash_objs[1].data = gsshdr->data;
1395         hash_objs[2].len = plain_out.len - ke->ke_conf_size - sizeof(*khdr);
1396         hash_objs[2].data = plain_out.data + ke->ke_conf_size;
1397         if (krb5_make_checksum(kctx->kc_enctype, &kctx->kc_keyi,
1398                                khdr, 3, hash_objs, 0, NULL, &cksum,
1399                                gctx->hash_func))
1400                 goto out_free;
1401
1402         LASSERT(cksum.len >= ke->ke_hash_size);
1403         if (memcmp((char *)(khdr + 1) + bodysize,
1404                    cksum.data + cksum.len - ke->ke_hash_size,
1405                    ke->ke_hash_size)) {
1406                 CERROR("checksum mismatch\n");
1407                 goto out_free;
1408         }
1409
1410         msg->len =  bodysize - ke->ke_conf_size - sizeof(*khdr);
1411         memcpy(msg->data, tmpbuf + ke->ke_conf_size, msg->len);
1412
1413         major = GSS_S_COMPLETE;
1414 out_free:
1415         OBD_FREE_LARGE(tmpbuf, bodysize);
1416         rawobj_free(&cksum);
1417         return major;
1418 }
1419
1420 static
1421 __u32 gss_unwrap_bulk_kerberos(struct gss_ctx *gctx,
1422                                struct ptlrpc_bulk_desc *desc,
1423                                rawobj_t *token, int adj_nob)
1424 {
1425         struct krb5_ctx     *kctx = gctx->internal_ctx_id;
1426         struct krb5_enctype *ke = &enctypes[kctx->kc_enctype];
1427         struct krb5_header  *khdr;
1428         int                  blocksize;
1429         rawobj_t             cksum = RAWOBJ_EMPTY;
1430         rawobj_t             cipher, plain;
1431         rawobj_t             data_desc[1];
1432         int                  rc;
1433         __u32                major;
1434
1435         LASSERT(ke);
1436
1437         if (token->len < sizeof(*khdr)) {
1438                 CERROR("short signature: %u\n", token->len);
1439                 return GSS_S_DEFECTIVE_TOKEN;
1440         }
1441
1442         khdr = (struct krb5_header *)token->data;
1443
1444         major = verify_krb5_header(kctx, khdr, 1);
1445         if (major != GSS_S_COMPLETE) {
1446                 CERROR("bad krb5 header\n");
1447                 return major;
1448         }
1449
1450         /* block size */
1451         if (kctx->kc_enctype == ENCTYPE_ARCFOUR_HMAC) {
1452                 LASSERT(kctx->kc_keye.kb_tfm == NULL);
1453                 blocksize = 1;
1454                 LBUG();
1455         } else {
1456                 LASSERT(kctx->kc_keye.kb_tfm);
1457                 blocksize = crypto_blkcipher_blocksize(kctx->kc_keye.kb_tfm);
1458         }
1459         LASSERT(sizeof(*khdr) >= blocksize && sizeof(*khdr) % blocksize == 0);
1460
1461         /*
1462          * token format is expected as:
1463          * -----------------------------------------------
1464          * | krb5 header | head/tail cipher text | cksum |
1465          * -----------------------------------------------
1466          */
1467         if (token->len < sizeof(*khdr) + blocksize + sizeof(*khdr) +
1468             ke->ke_hash_size) {
1469                 CERROR("short token size: %u\n", token->len);
1470                 return GSS_S_DEFECTIVE_TOKEN;
1471         }
1472
1473         cipher.data = (__u8 *) (khdr + 1);
1474         cipher.len = blocksize + sizeof(*khdr);
1475         plain.data = cipher.data;
1476         plain.len = cipher.len;
1477
1478         rc = krb5_decrypt_bulk(kctx->kc_keye.kb_tfm, khdr,
1479                                desc, &cipher, &plain, adj_nob);
1480         if (rc)
1481                 return GSS_S_DEFECTIVE_TOKEN;
1482
1483         /*
1484          * verify checksum, compose clear text as layout:
1485          * ------------------------------------------
1486          * | confounder | clear pages | krb5 header |
1487          * ------------------------------------------
1488          */
1489         data_desc[0].data = plain.data;
1490         data_desc[0].len = blocksize;
1491
1492         if (krb5_make_checksum(kctx->kc_enctype, &kctx->kc_keyi,
1493                                khdr, 1, data_desc,
1494                                desc->bd_iov_count,
1495                                desc->bd_vec,
1496                                &cksum, gctx->hash_func))
1497                 return GSS_S_FAILURE;
1498         LASSERT(cksum.len >= ke->ke_hash_size);
1499
1500         if (memcmp(plain.data + blocksize + sizeof(*khdr),
1501                    cksum.data + cksum.len - ke->ke_hash_size,
1502                    ke->ke_hash_size)) {
1503                 CERROR("checksum mismatch\n");
1504                 rawobj_free(&cksum);
1505                 return GSS_S_BAD_SIG;
1506         }
1507
1508         rawobj_free(&cksum);
1509         return GSS_S_COMPLETE;
1510 }
1511
1512 int gss_display_kerberos(struct gss_ctx        *ctx,
1513                          char                  *buf,
1514                          int                    bufsize)
1515 {
1516         struct krb5_ctx    *kctx = ctx->internal_ctx_id;
1517         int                 written;
1518
1519         written = snprintf(buf, bufsize, "krb5 (%s)",
1520                            enctype2str(kctx->kc_enctype));
1521         return written;
1522 }
1523
1524 static struct gss_api_ops gss_kerberos_ops = {
1525         .gss_import_sec_context     = gss_import_sec_context_kerberos,
1526         .gss_copy_reverse_context   = gss_copy_reverse_context_kerberos,
1527         .gss_inquire_context        = gss_inquire_context_kerberos,
1528         .gss_get_mic                = gss_get_mic_kerberos,
1529         .gss_verify_mic             = gss_verify_mic_kerberos,
1530         .gss_wrap                   = gss_wrap_kerberos,
1531         .gss_unwrap                 = gss_unwrap_kerberos,
1532         .gss_prep_bulk              = gss_prep_bulk_kerberos,
1533         .gss_wrap_bulk              = gss_wrap_bulk_kerberos,
1534         .gss_unwrap_bulk            = gss_unwrap_bulk_kerberos,
1535         .gss_delete_sec_context     = gss_delete_sec_context_kerberos,
1536         .gss_display                = gss_display_kerberos,
1537 };
1538
1539 static struct subflavor_desc gss_kerberos_sfs[] = {
1540         {
1541                 .sf_subflavor   = SPTLRPC_SUBFLVR_KRB5N,
1542                 .sf_qop         = 0,
1543                 .sf_service     = SPTLRPC_SVC_NULL,
1544                 .sf_name        = "krb5n"
1545         },
1546         {
1547                 .sf_subflavor   = SPTLRPC_SUBFLVR_KRB5A,
1548                 .sf_qop         = 0,
1549                 .sf_service     = SPTLRPC_SVC_AUTH,
1550                 .sf_name        = "krb5a"
1551         },
1552         {
1553                 .sf_subflavor   = SPTLRPC_SUBFLVR_KRB5I,
1554                 .sf_qop         = 0,
1555                 .sf_service     = SPTLRPC_SVC_INTG,
1556                 .sf_name        = "krb5i"
1557         },
1558         {
1559                 .sf_subflavor   = SPTLRPC_SUBFLVR_KRB5P,
1560                 .sf_qop         = 0,
1561                 .sf_service     = SPTLRPC_SVC_PRIV,
1562                 .sf_name        = "krb5p"
1563         },
1564 };
1565
1566 static struct gss_api_mech gss_kerberos_mech = {
1567         /* .gm_owner uses default NULL value for THIS_MODULE */
1568         .gm_name        = "krb5",
1569         .gm_oid         = (rawobj_t)
1570                                 {9, "\052\206\110\206\367\022\001\002\002"},
1571         .gm_ops         = &gss_kerberos_ops,
1572         .gm_sf_num      = 4,
1573         .gm_sfs         = gss_kerberos_sfs,
1574 };
1575
1576 int __init init_kerberos_module(void)
1577 {
1578         int status;
1579
1580         status = lgss_mech_register(&gss_kerberos_mech);
1581         if (status)
1582                 CERROR("Failed to register kerberos gss mechanism!\n");
1583         return status;
1584 }
1585
1586 void cleanup_kerberos_module(void)
1587 {
1588         lgss_mech_unregister(&gss_kerberos_mech);
1589 }