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         [ENCTYPE_DES3_CBC_RAW] = {              /* des3-hmac-sha1 */
  99                 .ke_dispname    = "des3-hmac-sha1",
 100                 .ke_enc_name    = "cbc(des3_ede)",
 101                 .ke_hash_name   = "sha1",
 102                 .ke_hash_size   = 20,
 103                 .ke_conf_size   = 8,
 104                 .ke_hash_hmac   = 1,
 105         },
 106         [ENCTYPE_AES128_CTS_HMAC_SHA1_96] = {   /* aes128-cts */
 107                 .ke_dispname    = "aes128-cts-hmac-sha1-96",
 108                 .ke_enc_name    = "cbc(aes)",
 109                 .ke_hash_name   = "sha1",
 110                 .ke_hash_size   = 12,
 111                 .ke_conf_size   = 16,
 112                 .ke_hash_hmac   = 1,
 113         },
 114         [ENCTYPE_AES256_CTS_HMAC_SHA1_96] = {   /* aes256-cts */
 115                 .ke_dispname    = "aes256-cts-hmac-sha1-96",
 116                 .ke_enc_name    = "cbc(aes)",
 117                 .ke_hash_name   = "sha1",
 118                 .ke_hash_size   = 12,
 119                 .ke_conf_size   = 16,
 120                 .ke_hash_hmac   = 1,
 121         },
 122         [ENCTYPE_ARCFOUR_HMAC] = {              /* arcfour-hmac-md5 */
 123                 .ke_dispname    = "arcfour-hmac-md5",
 124                 .ke_enc_name    = "ecb(arc4)",
 125                 .ke_hash_name   = "md5",
 126                 .ke_hash_size   = 16,
 127                 .ke_conf_size   = 8,
 128                 .ke_hash_hmac   = 1,
 129         }
 130 };
 131
 132 static const char * enctype2str(__u32 enctype)
 133 {
 134         if (enctype < ARRAY_SIZE(enctypes) && enctypes[enctype].ke_dispname)
 135                 return enctypes[enctype].ke_dispname;
 136
 137         return "unknown";
 138 }
 139
 140 static
 141 int krb5_init_keys(struct krb5_ctx *kctx)
 142 {
 143         struct krb5_enctype *ke;
 144
 145         if (kctx->kc_enctype >= ARRAY_SIZE(enctypes) ||
 146             enctypes[kctx->kc_enctype].ke_hash_size == 0) {
 147                 CERROR("unsupported enctype %x\n", kctx->kc_enctype);
 148                 return -1;
 149         }
 150
 151         ke = &enctypes[kctx->kc_enctype];
 152
 153         /* tfm arc4 is stateful, user should alloc-use-free by his own */
 154         if (kctx->kc_enctype != ENCTYPE_ARCFOUR_HMAC &&
 155             gss_keyblock_init(&kctx->kc_keye, ke->ke_enc_name, ke->ke_enc_mode))
 156                 return -1;
 157
 158         /* tfm hmac is stateful, user should alloc-use-free by his own */
 159         if (ke->ke_hash_hmac == 0 &&
 160             gss_keyblock_init(&kctx->kc_keyi, ke->ke_enc_name, ke->ke_enc_mode))
 161                 return -1;
 162         if (ke->ke_hash_hmac == 0 &&
 163             gss_keyblock_init(&kctx->kc_keyc, ke->ke_enc_name, ke->ke_enc_mode))
 164                 return -1;
 165
 166         return 0;
 167 }
 168
 169 static
 170 void delete_context_kerberos(struct krb5_ctx *kctx)
 171 {
 172         rawobj_free(&kctx->kc_mech_used);
 173
 174         gss_keyblock_free(&kctx->kc_keye);
 175         gss_keyblock_free(&kctx->kc_keyi);
 176         gss_keyblock_free(&kctx->kc_keyc);
 177 }
 178
 179 static
 180 __u32 import_context_rfc1964(struct krb5_ctx *kctx, char *p, char *end)
 181 {
 182         unsigned int    tmp_uint, keysize;
 183
 184         /* seed_init flag */
 185         if (gss_get_bytes(&p, end, &tmp_uint, sizeof(tmp_uint)))
 186                 goto out_err;
 187         kctx->kc_seed_init = (tmp_uint != 0);
 188
 189         /* seed */
 190         if (gss_get_bytes(&p, end, kctx->kc_seed, sizeof(kctx->kc_seed)))
 191                 goto out_err;
 192
 193         /* sign/seal algorithm, not really used now */
 194         if (gss_get_bytes(&p, end, &tmp_uint, sizeof(tmp_uint)) ||
 195             gss_get_bytes(&p, end, &tmp_uint, sizeof(tmp_uint)))
 196                 goto out_err;
 197
 198         /* end time. While kc_endtime might be 64 bit the krb5 API
 199          * still uses 32 bits. To delay the 2038 bug see the incoming
 200          * value as a u32 which give us until 2106. See the link for details:
 201          *
 202          * http://web.mit.edu/kerberos/www/krb5-current/doc/appdev/y2038.html
 203          */
 204         if (gss_get_bytes(&p, end, &kctx->kc_endtime, sizeof(u32)))
 205                 goto out_err;
 206
 207         /* seq send */
 208         if (gss_get_bytes(&p, end, &tmp_uint, sizeof(tmp_uint)))
 209                 goto out_err;
 210         kctx->kc_seq_send = tmp_uint;
 211
 212         /* mech oid */
 213         if (gss_get_rawobj(&p, end, &kctx->kc_mech_used))
 214                 goto out_err;
 215
 216         /* old style enc/seq keys in format:
 217          *   - enctype (u32)
 218          *   - keysize (u32)
 219          *   - keydata
 220          * we decompose them to fit into the new context
 221          */
 222
 223         /* enc key */
 224         if (gss_get_bytes(&p, end, &kctx->kc_enctype, sizeof(kctx->kc_enctype)))
 225                 goto out_err;
 226
 227         if (gss_get_bytes(&p, end, &keysize, sizeof(keysize)))
 228                 goto out_err;
 229
 230         if (gss_get_keyblock(&p, end, &kctx->kc_keye, keysize))
 231                 goto out_err;
 232
 233         /* seq key */
 234         if (gss_get_bytes(&p, end, &tmp_uint, sizeof(tmp_uint)) ||
 235             tmp_uint != kctx->kc_enctype)
 236                 goto out_err;
 237
 238         if (gss_get_bytes(&p, end, &tmp_uint, sizeof(tmp_uint)) ||
 239             tmp_uint != keysize)
 240                 goto out_err;
 241
 242         if (gss_get_keyblock(&p, end, &kctx->kc_keyc, keysize))
 243                 goto out_err;
 244
 245         /* old style fallback */
 246         if (gss_keyblock_dup(&kctx->kc_keyi, &kctx->kc_keyc))
 247                 goto out_err;
 248
 249         if (p != end)
 250                 goto out_err;
 251
 252         CDEBUG(D_SEC, "successfully imported rfc1964 context\n");
 253         return 0;
 254 out_err:
 255         return GSS_S_FAILURE;
 256 }
 257
 258 /* Flags for version 2 context flags */
 259 #define KRB5_CTX_FLAG_INITIATOR         0x00000001
 260 #define KRB5_CTX_FLAG_CFX               0x00000002
 261 #define KRB5_CTX_FLAG_ACCEPTOR_SUBKEY   0x00000004
 262
 263 static
 264 __u32 import_context_rfc4121(struct krb5_ctx *kctx, char *p, char *end)
 265 {
 266         unsigned int    tmp_uint, keysize;
 267
 268         /* end time. While kc_endtime might be 64 bit the krb5 API
 269          * still uses 32 bits. To delay the 2038 bug see the incoming
 270          * value as a u32 which give us until 2106. See the link for details:
 271          *
 272          * http://web.mit.edu/kerberos/www/krb5-current/doc/appdev/y2038.html
 273          */
 274         if (gss_get_bytes(&p, end, &kctx->kc_endtime, sizeof(u32)))
 275                 goto out_err;
 276
 277         /* flags */
 278         if (gss_get_bytes(&p, end, &tmp_uint, sizeof(tmp_uint)))
 279                 goto out_err;
 280
 281         if (tmp_uint & KRB5_CTX_FLAG_INITIATOR)
 282                 kctx->kc_initiate = 1;
 283         if (tmp_uint & KRB5_CTX_FLAG_CFX)
 284                 kctx->kc_cfx = 1;
 285         if (tmp_uint & KRB5_CTX_FLAG_ACCEPTOR_SUBKEY)
 286                 kctx->kc_have_acceptor_subkey = 1;
 287
 288         /* seq send */
 289         if (gss_get_bytes(&p, end, &kctx->kc_seq_send,
 290             sizeof(kctx->kc_seq_send)))
 291                 goto out_err;
 292
 293         /* enctype */
 294         if (gss_get_bytes(&p, end, &kctx->kc_enctype, sizeof(kctx->kc_enctype)))
 295                 goto out_err;
 296
 297         /* size of each key */
 298         if (gss_get_bytes(&p, end, &keysize, sizeof(keysize)))
 299                 goto out_err;
 300
 301         /* number of keys - should always be 3 */
 302         if (gss_get_bytes(&p, end, &tmp_uint, sizeof(tmp_uint)))
 303                 goto out_err;
 304
 305         if (tmp_uint != 3) {
 306                 CERROR("Invalid number of keys: %u\n", tmp_uint);
 307                 goto out_err;
 308         }
 309
 310         /* ke */
 311         if (gss_get_keyblock(&p, end, &kctx->kc_keye, keysize))
 312                 goto out_err;
 313         /* ki */
 314         if (gss_get_keyblock(&p, end, &kctx->kc_keyi, keysize))
 315                 goto out_err;
 316         /* ki */
 317         if (gss_get_keyblock(&p, end, &kctx->kc_keyc, keysize))
 318                 goto out_err;
 319
 320         CDEBUG(D_SEC, "successfully imported v2 context\n");
 321         return 0;
 322 out_err:
 323         return GSS_S_FAILURE;
 324 }
 325
 326 /*
 327  * The whole purpose here is trying to keep user level gss context parsing
 328  * from nfs-utils unchanged as possible as we can, they are not quite mature
 329  * yet, and many stuff still not clear, like heimdal etc.
 330  */
 331 static
 332 __u32 gss_import_sec_context_kerberos(rawobj_t *inbuf,
 333                                       struct gss_ctx *gctx)
 334 {
 335         struct krb5_ctx *kctx;
 336         char *p = (char *)inbuf->data;
 337         char *end = (char *)(inbuf->data + inbuf->len);
 338         unsigned int tmp_uint, rc;
 339
 340         if (gss_get_bytes(&p, end, &tmp_uint, sizeof(tmp_uint))) {
 341                 CERROR("Fail to read version\n");
 342                 return GSS_S_FAILURE;
 343         }
 344
 345         /* only support 0, 1 for the moment */
 346         if (tmp_uint > 2) {
 347                 CERROR("Invalid version %u\n", tmp_uint);
 348                 return GSS_S_FAILURE;
 349         }
 350
 351         OBD_ALLOC_PTR(kctx);
 352         if (!kctx)
 353                 return GSS_S_FAILURE;
 354
 355         if (tmp_uint == 0 || tmp_uint == 1) {
 356                 kctx->kc_initiate = tmp_uint;
 357                 rc = import_context_rfc1964(kctx, p, end);
 358         } else {
 359                 rc = import_context_rfc4121(kctx, p, end);
 360         }
 361
 362         if (rc == 0)
 363                 rc = krb5_init_keys(kctx);
 364
 365         if (rc) {
 366                 delete_context_kerberos(kctx);
 367                 OBD_FREE_PTR(kctx);
 368
 369                 return GSS_S_FAILURE;
 370         }
 371
 372         gctx->internal_ctx_id = kctx;
 373         return GSS_S_COMPLETE;
 374 }
 375
 376 static
 377 __u32 gss_copy_reverse_context_kerberos(struct gss_ctx *gctx,
 378                                         struct gss_ctx *gctx_new)
 379 {
 380         struct krb5_ctx *kctx = gctx->internal_ctx_id;
 381         struct krb5_ctx *knew;
 382
 383         OBD_ALLOC_PTR(knew);
 384         if (!knew)
 385                 return GSS_S_FAILURE;
 386
 387         knew->kc_initiate = kctx->kc_initiate ? 0 : 1;
 388         knew->kc_cfx = kctx->kc_cfx;
 389         knew->kc_seed_init = kctx->kc_seed_init;
 390         knew->kc_have_acceptor_subkey = kctx->kc_have_acceptor_subkey;
 391         knew->kc_endtime = kctx->kc_endtime;
 392
 393         memcpy(knew->kc_seed, kctx->kc_seed, sizeof(kctx->kc_seed));
 394         knew->kc_seq_send = kctx->kc_seq_recv;
 395         knew->kc_seq_recv = kctx->kc_seq_send;
 396         knew->kc_enctype = kctx->kc_enctype;
 397
 398         if (rawobj_dup(&knew->kc_mech_used, &kctx->kc_mech_used))
 399                 goto out_err;
 400
 401         if (gss_keyblock_dup(&knew->kc_keye, &kctx->kc_keye))
 402                 goto out_err;
 403         if (gss_keyblock_dup(&knew->kc_keyi, &kctx->kc_keyi))
 404                 goto out_err;
 405         if (gss_keyblock_dup(&knew->kc_keyc, &kctx->kc_keyc))
 406                 goto out_err;
 407         if (krb5_init_keys(knew))
 408                 goto out_err;
 409
 410         gctx_new->internal_ctx_id = knew;
 411         CDEBUG(D_SEC, "successfully copied reverse context\n");
 412         return GSS_S_COMPLETE;
 413
 414 out_err:
 415         delete_context_kerberos(knew);
 416         OBD_FREE_PTR(knew);
 417         return GSS_S_FAILURE;
 418 }
 419
 420 static
 421 __u32 gss_inquire_context_kerberos(struct gss_ctx *gctx,
 422                                    time64_t *endtime)
 423 {
 424         struct krb5_ctx *kctx = gctx->internal_ctx_id;
 425
 426         *endtime = kctx->kc_endtime;
 427         return GSS_S_COMPLETE;
 428 }
 429
 430 static
 431 void gss_delete_sec_context_kerberos(void *internal_ctx)
 432 {
 433         struct krb5_ctx *kctx = internal_ctx;
 434
 435         delete_context_kerberos(kctx);
 436         OBD_FREE_PTR(kctx);
 437 }
 438
 439 /*
 440  * compute (keyed/keyless) checksum against the plain text which appended
 441  * with krb5 wire token header.
 442  */
 443 static
 444 __s32 krb5_make_checksum(__u32 enctype,
 445                          struct gss_keyblock *kb,
 446                          struct krb5_header *khdr,
 447                          int msgcnt, rawobj_t *msgs,
 448                          int iovcnt, lnet_kiov_t *iovs,
 449                          rawobj_t *cksum,
 450                          digest_hash hash_func)
 451 {
 452         struct krb5_enctype *ke = &enctypes[enctype];
 453         struct ahash_request *req = NULL;
 454         enum cfs_crypto_hash_alg hash_algo;
 455         rawobj_t hdr;
 456         int rc;
 457
 458         hash_algo = cfs_crypto_hash_alg(ke->ke_hash_name);
 459
 460         /* For the cbc(des) case we want md5 instead of hmac(md5) */
 461         if (strcmp(ke->ke_enc_name, "cbc(des)"))
 462                 req = cfs_crypto_hash_init(hash_algo, kb->kb_key.data,
 463                                            kb->kb_key.len);
 464         else
 465                 req = cfs_crypto_hash_init(hash_algo, NULL, 0);
 466         if (IS_ERR(req)) {
 467                 rc = PTR_ERR(req);
 468                 CERROR("failed to alloc hash %s : rc = %d\n",
 469                        ke->ke_hash_name, rc);
 470                 goto out_no_hash;
 471         }
 472
 473         cksum->len = cfs_crypto_hash_digestsize(hash_algo);
 474         OBD_ALLOC_LARGE(cksum->data, cksum->len);
 475         if (!cksum->data) {
 476                 cksum->len = 0;
 477                 rc = -ENOMEM;
 478                 goto out_free_hash;
 479         }
 480
 481         hdr.data = (__u8 *)khdr;
 482         hdr.len = sizeof(*khdr);
 483
 484         if (!hash_func) {
 485                 rc = -EPROTO;
 486                 CERROR("hash function for %s undefined\n",
 487                        ke->ke_hash_name);
 488                 goto out_free_hash;
 489         }
 490         rc = hash_func(req, &hdr, msgcnt, msgs, iovcnt, iovs);
 491         if (rc)
 492                 goto out_free_hash;
 493
 494         if (!ke->ke_hash_hmac) {
 495                 LASSERT(kb->kb_tfm);
 496
 497                 cfs_crypto_hash_final(req, cksum->data, &cksum->len);
 498                 rc = gss_crypt_generic(kb->kb_tfm, 0, NULL,
 499                                        cksum->data, cksum->data,
 500                                        cksum->len);
 501                 goto out_no_hash;
 502         }
 503
 504 out_free_hash:
 505         if (req)
 506                 cfs_crypto_hash_final(req, cksum->data, &cksum->len);
 507 out_no_hash:
 508         return rc ? GSS_S_FAILURE : GSS_S_COMPLETE;
 509 }
 510
 511 static void fill_krb5_header(struct krb5_ctx *kctx,
 512                              struct krb5_header *khdr,
 513                              int privacy)
 514 {
 515         unsigned char acceptor_flag;
 516
 517         acceptor_flag = kctx->kc_initiate ? 0 : FLAG_SENDER_IS_ACCEPTOR;
 518
 519         if (privacy) {
 520                 khdr->kh_tok_id = cpu_to_be16(KG_TOK_WRAP_MSG);
 521                 khdr->kh_flags = acceptor_flag | FLAG_WRAP_CONFIDENTIAL;
 522                 khdr->kh_ec = cpu_to_be16(0);
 523                 khdr->kh_rrc = cpu_to_be16(0);
 524         } else {
 525                 khdr->kh_tok_id = cpu_to_be16(KG_TOK_MIC_MSG);
 526                 khdr->kh_flags = acceptor_flag;
 527                 khdr->kh_ec = cpu_to_be16(0xffff);
 528                 khdr->kh_rrc = cpu_to_be16(0xffff);
 529         }
 530
 531         khdr->kh_filler = 0xff;
 532         spin_lock(&krb5_seq_lock);
 533         khdr->kh_seq = cpu_to_be64(kctx->kc_seq_send++);
 534         spin_unlock(&krb5_seq_lock);
 535 }
 536
 537 static __u32 verify_krb5_header(struct krb5_ctx *kctx,
 538                                 struct krb5_header *khdr,
 539                                 int privacy)
 540 {
 541         unsigned char acceptor_flag;
 542         __u16         tok_id, ec_rrc;
 543
 544         acceptor_flag = kctx->kc_initiate ? FLAG_SENDER_IS_ACCEPTOR : 0;
 545
 546         if (privacy) {
 547                 tok_id = KG_TOK_WRAP_MSG;
 548                 ec_rrc = 0x0;
 549         } else {
 550                 tok_id = KG_TOK_MIC_MSG;
 551                 ec_rrc = 0xffff;
 552         }
 553
 554         /* sanity checks */
 555         if (be16_to_cpu(khdr->kh_tok_id) != tok_id) {
 556                 CERROR("bad token id\n");
 557                 return GSS_S_DEFECTIVE_TOKEN;
 558         }
 559         if ((khdr->kh_flags & FLAG_SENDER_IS_ACCEPTOR) != acceptor_flag) {
 560                 CERROR("bad direction flag\n");
 561                 return GSS_S_BAD_SIG;
 562         }
 563         if (privacy && (khdr->kh_flags & FLAG_WRAP_CONFIDENTIAL) == 0) {
 564                 CERROR("missing confidential flag\n");
 565                 return GSS_S_BAD_SIG;
 566         }
 567         if (khdr->kh_filler != 0xff) {
 568                 CERROR("bad filler\n");
 569                 return GSS_S_DEFECTIVE_TOKEN;
 570         }
 571         if (be16_to_cpu(khdr->kh_ec) != ec_rrc ||
 572             be16_to_cpu(khdr->kh_rrc) != ec_rrc) {
 573                 CERROR("bad EC or RRC\n");
 574                 return GSS_S_DEFECTIVE_TOKEN;
 575         }
 576         return GSS_S_COMPLETE;
 577 }
 578
 579 static
 580 __u32 gss_get_mic_kerberos(struct gss_ctx *gctx,
 581                            int msgcnt,
 582                            rawobj_t *msgs,
 583                            int iovcnt,
 584                            lnet_kiov_t *iovs,
 585                            rawobj_t *token)
 586 {
 587         struct krb5_ctx     *kctx = gctx->internal_ctx_id;
 588         struct krb5_enctype *ke = &enctypes[kctx->kc_enctype];
 589         struct krb5_header  *khdr;
 590         rawobj_t cksum = RAWOBJ_EMPTY;
 591         u32 major;
 592
 593         /* fill krb5 header */
 594         LASSERT(token->len >= sizeof(*khdr));
 595         khdr = (struct krb5_header *)token->data;
 596         fill_krb5_header(kctx, khdr, 0);
 597
 598         /* checksum */
 599         if (krb5_make_checksum(kctx->kc_enctype, &kctx->kc_keyc, khdr,
 600                                msgcnt, msgs, iovcnt, iovs, &cksum,
 601                                gctx->hash_func))
 602                 GOTO(out_free_cksum, major = GSS_S_FAILURE);
 603
 604         LASSERT(cksum.len >= ke->ke_hash_size);
 605         LASSERT(token->len >= sizeof(*khdr) + ke->ke_hash_size);
 606         memcpy(khdr + 1, cksum.data + cksum.len - ke->ke_hash_size,
 607                ke->ke_hash_size);
 608
 609         token->len = sizeof(*khdr) + ke->ke_hash_size;
 610         major = GSS_S_COMPLETE;
 611 out_free_cksum:
 612         rawobj_free(&cksum);
 613         return major;
 614 }
 615
 616 static
 617 __u32 gss_verify_mic_kerberos(struct gss_ctx *gctx,
 618                               int msgcnt,
 619                               rawobj_t *msgs,
 620                               int iovcnt,
 621                               lnet_kiov_t *iovs,
 622                               rawobj_t *token)
 623 {
 624         struct krb5_ctx *kctx = gctx->internal_ctx_id;
 625         struct krb5_enctype *ke = &enctypes[kctx->kc_enctype];
 626         struct krb5_header *khdr;
 627         rawobj_t cksum = RAWOBJ_EMPTY;
 628         u32 major;
 629
 630         if (token->len < sizeof(*khdr)) {
 631                 CERROR("short signature: %u\n", token->len);
 632                 return GSS_S_DEFECTIVE_TOKEN;
 633         }
 634
 635         khdr = (struct krb5_header *)token->data;
 636
 637         major = verify_krb5_header(kctx, khdr, 0);
 638         if (major != GSS_S_COMPLETE) {
 639                 CERROR("bad krb5 header\n");
 640                 goto out;
 641         }
 642
 643         if (token->len < sizeof(*khdr) + ke->ke_hash_size) {
 644                 CERROR("short signature: %u, require %d\n",
 645                        token->len, (int) sizeof(*khdr) + ke->ke_hash_size);
 646                 GOTO(out, major = GSS_S_FAILURE);
 647         }
 648
 649         if (krb5_make_checksum(kctx->kc_enctype, &kctx->kc_keyc,
 650                                khdr, msgcnt, msgs, iovcnt, iovs, &cksum,
 651                                gctx->hash_func))
 652                 GOTO(out_free_cksum, major = GSS_S_FAILURE);
 653
 654         LASSERT(cksum.len >= ke->ke_hash_size);
 655         if (memcmp(khdr + 1, cksum.data + cksum.len - ke->ke_hash_size,
 656                    ke->ke_hash_size)) {
 657                 CERROR("checksum mismatch\n");
 658                 GOTO(out_free_cksum, major = GSS_S_BAD_SIG);
 659         }
 660         major = GSS_S_COMPLETE;
 661 out_free_cksum:
 662         rawobj_free(&cksum);
 663 out:
 664         return major;
 665 }
 666
 667 /*
 668  * if adj_nob != 0, we adjust desc->bd_nob to the actual cipher text size.
 669  */
 670 static
 671 int krb5_encrypt_bulk(struct crypto_blkcipher *tfm,
 672                       struct krb5_header *khdr,
 673                       char *confounder,
 674                       struct ptlrpc_bulk_desc *desc,
 675                       rawobj_t *cipher,
 676                       int adj_nob)
 677 {
 678         struct blkcipher_desc   ciph_desc;
 679         __u8                    local_iv[16] = {0};
 680         struct scatterlist      src, dst;
 681         struct sg_table         sg_src, sg_dst;
 682         int                     blocksize, i, rc, nob = 0;
 683
 684         LASSERT(ptlrpc_is_bulk_desc_kiov(desc->bd_type));
 685         LASSERT(desc->bd_iov_count);
 686         LASSERT(GET_ENC_KIOV(desc));
 687
 688         blocksize = crypto_blkcipher_blocksize(tfm);
 689         LASSERT(blocksize > 1);
 690         LASSERT(cipher->len == blocksize + sizeof(*khdr));
 691
 692         ciph_desc.tfm  = tfm;
 693         ciph_desc.info = local_iv;
 694         ciph_desc.flags = 0;
 695
 696         /* encrypt confounder */
 697         rc = gss_setup_sgtable(&sg_src, &src, confounder, blocksize);
 698         if (rc != 0)
 699                 return rc;
 700
 701         rc = gss_setup_sgtable(&sg_dst, &dst, cipher->data, blocksize);
 702         if (rc != 0) {
 703                 gss_teardown_sgtable(&sg_src);
 704                 return rc;
 705         }
 706
 707         rc = crypto_blkcipher_encrypt_iv(&ciph_desc, sg_dst.sgl,
 708                                          sg_src.sgl, blocksize);
 709
 710         gss_teardown_sgtable(&sg_dst);
 711         gss_teardown_sgtable(&sg_src);
 712
 713         if (rc) {
 714                 CERROR("error to encrypt confounder: %d\n", rc);
 715                 return rc;
 716         }
 717
 718         /* encrypt clear pages */
 719         for (i = 0; i < desc->bd_iov_count; i++) {
 720                 sg_init_table(&src, 1);
 721                 sg_set_page(&src, BD_GET_KIOV(desc, i).kiov_page,
 722                             (BD_GET_KIOV(desc, i).kiov_len +
 723                                 blocksize - 1) &
 724                             (~(blocksize - 1)),
 725                             BD_GET_KIOV(desc, i).kiov_offset);
 726                 if (adj_nob)
 727                         nob += src.length;
 728                 sg_init_table(&dst, 1);
 729                 sg_set_page(&dst, BD_GET_ENC_KIOV(desc, i).kiov_page,
 730                             src.length, src.offset);
 731
 732                 BD_GET_ENC_KIOV(desc, i).kiov_offset = dst.offset;
 733                 BD_GET_ENC_KIOV(desc, i).kiov_len = dst.length;
 734
 735                 rc = crypto_blkcipher_encrypt_iv(&ciph_desc, &dst, &src,
 736                                                     src.length);
 737                 if (rc) {
 738                         CERROR("error to encrypt page: %d\n", rc);
 739                         return rc;
 740                 }
 741         }
 742
 743         /* encrypt krb5 header */
 744         rc = gss_setup_sgtable(&sg_src, &src, khdr, sizeof(*khdr));
 745         if (rc != 0)
 746                 return rc;
 747
 748         rc = gss_setup_sgtable(&sg_dst, &dst, cipher->data + blocksize,
 749                            sizeof(*khdr));
 750         if (rc != 0) {
 751                 gss_teardown_sgtable(&sg_src);
 752                 return rc;
 753         }
 754
 755         rc = crypto_blkcipher_encrypt_iv(&ciph_desc, sg_dst.sgl, sg_src.sgl,
 756                                          sizeof(*khdr));
 757
 758         gss_teardown_sgtable(&sg_dst);
 759         gss_teardown_sgtable(&sg_src);
 760
 761         if (rc) {
 762                 CERROR("error to encrypt krb5 header: %d\n", rc);
 763                 return rc;
 764         }
 765
 766         if (adj_nob)
 767                 desc->bd_nob = nob;
 768
 769         return 0;
 770 }
 771
 772 /*
 773  * desc->bd_nob_transferred is the size of cipher text received.
 774  * desc->bd_nob is the target size of plain text supposed to be.
 775  *
 776  * if adj_nob != 0, we adjust each page's kiov_len to the actual
 777  * plain text size.
 778  * - for client read: we don't know data size for each page, so
 779  *   bd_iov[]->kiov_len is set to PAGE_SIZE, but actual data received might
 780  *   be smaller, so we need to adjust it according to
 781  *   bd_u.bd_kiov.bd_enc_vec[]->kiov_len.
 782  *   this means we DO NOT support the situation that server send an odd size
 783  *   data in a page which is not the last one.
 784  * - for server write: we knows exactly data size for each page being expected,
 785  *   thus kiov_len is accurate already, so we should not adjust it at all.
 786  *   and bd_u.bd_kiov.bd_enc_vec[]->kiov_len should be
 787  *   round_up(bd_iov[]->kiov_len) which
 788  *   should have been done by prep_bulk().
 789  */
 790 static
 791 int krb5_decrypt_bulk(struct crypto_blkcipher *tfm,
 792                       struct krb5_header *khdr,
 793                       struct ptlrpc_bulk_desc *desc,
 794                       rawobj_t *cipher,
 795                       rawobj_t *plain,
 796                       int adj_nob)
 797 {
 798         struct blkcipher_desc   ciph_desc;
 799         __u8                    local_iv[16] = {0};
 800         struct scatterlist      src, dst;
 801         struct sg_table         sg_src, sg_dst;
 802         int                     ct_nob = 0, pt_nob = 0;
 803         int                     blocksize, i, rc;
 804
 805         LASSERT(ptlrpc_is_bulk_desc_kiov(desc->bd_type));
 806         LASSERT(desc->bd_iov_count);
 807         LASSERT(GET_ENC_KIOV(desc));
 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 (BD_GET_ENC_KIOV(desc, i).kiov_offset % blocksize
 848                     != 0 ||
 849                     BD_GET_ENC_KIOV(desc, i).kiov_len % blocksize
 850                     != 0) {
 851                         CERROR("page %d: odd offset %u len %u, blocksize %d\n",
 852                                i, BD_GET_ENC_KIOV(desc, i).kiov_offset,
 853                                BD_GET_ENC_KIOV(desc, i).kiov_len,
 854                                blocksize);
 855                         return -EFAULT;
 856                 }
 857
 858                 if (adj_nob) {
 859                         if (ct_nob + BD_GET_ENC_KIOV(desc, i).kiov_len >
 860                             desc->bd_nob_transferred)
 861                                 BD_GET_ENC_KIOV(desc, i).kiov_len =
 862                                         desc->bd_nob_transferred - ct_nob;
 863
 864                         BD_GET_KIOV(desc, i).kiov_len =
 865                           BD_GET_ENC_KIOV(desc, i).kiov_len;
 866                         if (pt_nob + BD_GET_ENC_KIOV(desc, i).kiov_len >
 867                             desc->bd_nob)
 868                                 BD_GET_KIOV(desc, i).kiov_len =
 869                                   desc->bd_nob - pt_nob;
 870                 } else {
 871                         /* this should be guaranteed by LNET */
 872                         LASSERT(ct_nob + BD_GET_ENC_KIOV(desc, i).
 873                                 kiov_len <=
 874                                 desc->bd_nob_transferred);
 875                         LASSERT(BD_GET_KIOV(desc, i).kiov_len <=
 876                                 BD_GET_ENC_KIOV(desc, i).kiov_len);
 877                 }
 878
 879                 if (BD_GET_ENC_KIOV(desc, i).kiov_len == 0)
 880                         continue;
 881
 882                 sg_init_table(&src, 1);
 883                 sg_set_page(&src, BD_GET_ENC_KIOV(desc, i).kiov_page,
 884                             BD_GET_ENC_KIOV(desc, i).kiov_len,
 885                             BD_GET_ENC_KIOV(desc, i).kiov_offset);
 886                 dst = src;
 887                 if (BD_GET_KIOV(desc, i).kiov_len % blocksize == 0)
 888                         sg_assign_page(&dst,
 889                                        BD_GET_KIOV(desc, i).kiov_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 (BD_GET_KIOV(desc, i).kiov_len % blocksize != 0) {
 899                         memcpy(page_address(BD_GET_KIOV(desc, i).kiov_page) +
 900                                BD_GET_KIOV(desc, i).kiov_offset,
 901                                page_address(BD_GET_ENC_KIOV(desc, i).
 902                                             kiov_page) +
 903                                BD_GET_KIOV(desc, i).kiov_offset,
 904                                BD_GET_KIOV(desc, i).kiov_len);
 905                 }
 906
 907                 ct_nob += BD_GET_ENC_KIOV(desc, i).kiov_len;
 908                 pt_nob += BD_GET_KIOV(desc, i).kiov_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                         BD_GET_KIOV(desc, i++).kiov_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(ptlrpc_is_bulk_desc_kiov(desc->bd_type));
1112         LASSERT(desc->bd_iov_count);
1113         LASSERT(GET_ENC_KIOV(desc));
1114         LASSERT(kctx->kc_keye.kb_tfm);
1115
1116         blocksize = crypto_blkcipher_blocksize(kctx->kc_keye.kb_tfm);
1117
1118         for (i = 0; i < desc->bd_iov_count; i++) {
1119                 LASSERT(BD_GET_ENC_KIOV(desc, i).kiov_page);
1120                 /*
1121                  * offset should always start at page boundary of either
1122                  * client or server side.
1123                  */
1124                 if (BD_GET_KIOV(desc, i).kiov_offset & blocksize) {
1125                         CERROR("odd offset %d in page %d\n",
1126                                BD_GET_KIOV(desc, i).kiov_offset, i);
1127                         return GSS_S_FAILURE;
1128                 }
1129
1130                 BD_GET_ENC_KIOV(desc, i).kiov_offset =
1131                         BD_GET_KIOV(desc, i).kiov_offset;
1132                 BD_GET_ENC_KIOV(desc, i).kiov_len =
1133                         (BD_GET_KIOV(desc, i).kiov_len +
1134                          blocksize - 1) & (~(blocksize - 1));
1135         }
1136
1137         return GSS_S_COMPLETE;
1138 }
1139
1140 static
1141 __u32 gss_wrap_bulk_kerberos(struct gss_ctx *gctx,
1142                              struct ptlrpc_bulk_desc *desc,
1143                              rawobj_t *token, int adj_nob)
1144 {
1145         struct krb5_ctx     *kctx = gctx->internal_ctx_id;
1146         struct krb5_enctype *ke = &enctypes[kctx->kc_enctype];
1147         struct krb5_header  *khdr;
1148         int                  blocksize;
1149         rawobj_t             cksum = RAWOBJ_EMPTY;
1150         rawobj_t             data_desc[1], cipher;
1151         __u8                 conf[GSS_MAX_CIPHER_BLOCK];
1152         int rc = 0;
1153         u32 major;
1154
1155         LASSERT(ptlrpc_is_bulk_desc_kiov(desc->bd_type));
1156         LASSERT(ke);
1157         LASSERT(ke->ke_conf_size <= GSS_MAX_CIPHER_BLOCK);
1158
1159         /*
1160          * final token format:
1161          * --------------------------------------------------
1162          * | krb5 header | head/tail cipher text | checksum |
1163          * --------------------------------------------------
1164          */
1165
1166         /* fill krb5 header */
1167         LASSERT(token->len >= sizeof(*khdr));
1168         khdr = (struct krb5_header *)token->data;
1169         fill_krb5_header(kctx, khdr, 1);
1170
1171         /* generate confounder */
1172         get_random_bytes(conf, ke->ke_conf_size);
1173
1174         /* get encryption blocksize. note kc_keye might not associated with
1175          * a tfm, currently only for arcfour-hmac */
1176         if (kctx->kc_enctype == ENCTYPE_ARCFOUR_HMAC) {
1177                 LASSERT(kctx->kc_keye.kb_tfm == NULL);
1178                 blocksize = 1;
1179         } else {
1180                 LASSERT(kctx->kc_keye.kb_tfm);
1181                 blocksize = crypto_blkcipher_blocksize(kctx->kc_keye.kb_tfm);
1182         }
1183
1184         /*
1185          * we assume the size of krb5_header (16 bytes) must be n * blocksize.
1186          * the bulk token size would be exactly (sizeof(krb5_header) +
1187          * blocksize + sizeof(krb5_header) + hashsize)
1188          */
1189         LASSERT(blocksize <= ke->ke_conf_size);
1190         LASSERT(sizeof(*khdr) >= blocksize && sizeof(*khdr) % blocksize == 0);
1191         LASSERT(token->len >= sizeof(*khdr) + blocksize + sizeof(*khdr) + 16);
1192
1193         /*
1194          * clear text layout for checksum:
1195          * ------------------------------------------
1196          * | confounder | clear pages | krb5 header |
1197          * ------------------------------------------
1198          */
1199         data_desc[0].data = conf;
1200         data_desc[0].len = ke->ke_conf_size;
1201
1202         /* compute checksum */
1203         if (krb5_make_checksum(kctx->kc_enctype, &kctx->kc_keyi,
1204                                khdr, 1, data_desc,
1205                                desc->bd_iov_count, GET_KIOV(desc),
1206                                &cksum, gctx->hash_func))
1207                 GOTO(out_free_cksum, major = GSS_S_FAILURE);
1208         LASSERT(cksum.len >= ke->ke_hash_size);
1209
1210         /*
1211          * clear text layout for encryption:
1212          * ------------------------------------------
1213          * | confounder | clear pages | krb5 header |
1214          * ------------------------------------------
1215          *        |              |             |
1216          *        ----------  (cipher pages)   |
1217          * result token:   |                   |
1218          * -------------------------------------------
1219          * | krb5 header | cipher text | cipher text |
1220          * -------------------------------------------
1221          */
1222         data_desc[0].data = conf;
1223         data_desc[0].len = ke->ke_conf_size;
1224
1225         cipher.data = (__u8 *)(khdr + 1);
1226         cipher.len = blocksize + sizeof(*khdr);
1227
1228         if (kctx->kc_enctype == ENCTYPE_ARCFOUR_HMAC) {
1229                 LBUG();
1230                 rc = 0;
1231         } else {
1232                 rc = krb5_encrypt_bulk(kctx->kc_keye.kb_tfm, khdr,
1233                                        conf, desc, &cipher, adj_nob);
1234         }
1235         if (rc)
1236                 GOTO(out_free_cksum, major = GSS_S_FAILURE);
1237
1238         /* fill in checksum */
1239         LASSERT(token->len >= sizeof(*khdr) + cipher.len + ke->ke_hash_size);
1240         memcpy((char *)(khdr + 1) + cipher.len,
1241                cksum.data + cksum.len - ke->ke_hash_size,
1242                ke->ke_hash_size);
1243
1244         /* final token length */
1245         token->len = sizeof(*khdr) + cipher.len + ke->ke_hash_size;
1246         major = GSS_S_COMPLETE;
1247 out_free_cksum:
1248         rawobj_free(&cksum);
1249         return major;
1250 }
1251
1252 static
1253 __u32 gss_unwrap_kerberos(struct gss_ctx  *gctx,
1254                           rawobj_t        *gsshdr,
1255                           rawobj_t        *token,
1256                           rawobj_t        *msg)
1257 {
1258         struct krb5_ctx     *kctx = gctx->internal_ctx_id;
1259         struct krb5_enctype *ke = &enctypes[kctx->kc_enctype];
1260         struct krb5_header  *khdr;
1261         unsigned char       *tmpbuf;
1262         int                  blocksize, bodysize;
1263         rawobj_t             cksum = RAWOBJ_EMPTY;
1264         rawobj_t             cipher_in, plain_out;
1265         rawobj_t             hash_objs[3];
1266         int                  rc = 0;
1267         __u32                major;
1268         __u8                 local_iv[16] = {0};
1269
1270         LASSERT(ke);
1271
1272         if (token->len < sizeof(*khdr)) {
1273                 CERROR("short signature: %u\n", token->len);
1274                 return GSS_S_DEFECTIVE_TOKEN;
1275         }
1276
1277         khdr = (struct krb5_header *)token->data;
1278
1279         major = verify_krb5_header(kctx, khdr, 1);
1280         if (major != GSS_S_COMPLETE) {
1281                 CERROR("bad krb5 header\n");
1282                 return major;
1283         }
1284
1285         /* block size */
1286         if (kctx->kc_enctype == ENCTYPE_ARCFOUR_HMAC) {
1287                 LASSERT(kctx->kc_keye.kb_tfm == NULL);
1288                 blocksize = 1;
1289         } else {
1290                 LASSERT(kctx->kc_keye.kb_tfm);
1291                 blocksize = crypto_blkcipher_blocksize(kctx->kc_keye.kb_tfm);
1292         }
1293
1294         /* expected token layout:
1295          * ----------------------------------------
1296          * | krb5 header | cipher text | checksum |
1297          * ----------------------------------------
1298          */
1299         bodysize = token->len - sizeof(*khdr) - ke->ke_hash_size;
1300
1301         if (bodysize % blocksize) {
1302                 CERROR("odd bodysize %d\n", bodysize);
1303                 return GSS_S_DEFECTIVE_TOKEN;
1304         }
1305
1306         if (bodysize <= ke->ke_conf_size + sizeof(*khdr)) {
1307                 CERROR("incomplete token: bodysize %d\n", bodysize);
1308                 return GSS_S_DEFECTIVE_TOKEN;
1309         }
1310
1311         if (msg->len < bodysize - ke->ke_conf_size - sizeof(*khdr)) {
1312                 CERROR("buffer too small: %u, require %d\n",
1313                        msg->len, bodysize - ke->ke_conf_size);
1314                 return GSS_S_FAILURE;
1315         }
1316
1317         /* decrypting */
1318         OBD_ALLOC_LARGE(tmpbuf, bodysize);
1319         if (!tmpbuf)
1320                 return GSS_S_FAILURE;
1321
1322         major = GSS_S_FAILURE;
1323
1324         cipher_in.data = (__u8 *)(khdr + 1);
1325         cipher_in.len = bodysize;
1326         plain_out.data = tmpbuf;
1327         plain_out.len = bodysize;
1328
1329         if (kctx->kc_enctype == ENCTYPE_ARCFOUR_HMAC) {
1330                 rawobj_t                 arc4_keye;
1331                 struct crypto_blkcipher *arc4_tfm;
1332
1333                 cksum.data = token->data + token->len - ke->ke_hash_size;
1334                 cksum.len = ke->ke_hash_size;
1335
1336                 if (krb5_make_checksum(ENCTYPE_ARCFOUR_HMAC, &kctx->kc_keyi,
1337                                        NULL, 1, &cksum, 0, NULL, &arc4_keye,
1338                                        gctx->hash_func)) {
1339                         CERROR("failed to obtain arc4 enc key\n");
1340                         GOTO(arc4_out, rc = -EACCES);
1341                 }
1342
1343                 arc4_tfm = crypto_alloc_blkcipher("ecb(arc4)", 0, 0);
1344                 if (IS_ERR(arc4_tfm)) {
1345                         CERROR("failed to alloc tfm arc4 in ECB mode\n");
1346                         GOTO(arc4_out_key, rc = -EACCES);
1347                 }
1348
1349                 if (crypto_blkcipher_setkey(arc4_tfm,
1350                                             arc4_keye.data, arc4_keye.len)) {
1351                         CERROR("failed to set arc4 key, len %d\n",
1352                                arc4_keye.len);
1353                         GOTO(arc4_out_tfm, rc = -EACCES);
1354                 }
1355
1356                 rc = gss_crypt_rawobjs(arc4_tfm, NULL, 1, &cipher_in,
1357                                        &plain_out, 0);
1358 arc4_out_tfm:
1359                 crypto_free_blkcipher(arc4_tfm);
1360 arc4_out_key:
1361                 rawobj_free(&arc4_keye);
1362 arc4_out:
1363                 cksum = RAWOBJ_EMPTY;
1364         } else {
1365                 rc = gss_crypt_rawobjs(kctx->kc_keye.kb_tfm, local_iv, 1,
1366                                        &cipher_in, &plain_out, 0);
1367         }
1368
1369         if (rc != 0) {
1370                 CERROR("error decrypt\n");
1371                 goto out_free;
1372         }
1373         LASSERT(plain_out.len == bodysize);
1374
1375         /* expected clear text layout:
1376          * -----------------------------------------
1377          * | confounder | clear msgs | krb5 header |
1378          * -----------------------------------------
1379          */
1380
1381         /* verify krb5 header in token is not modified */
1382         if (memcmp(khdr, plain_out.data + plain_out.len - sizeof(*khdr),
1383                    sizeof(*khdr))) {
1384                 CERROR("decrypted krb5 header mismatch\n");
1385                 goto out_free;
1386         }
1387
1388         /* verify checksum, compose clear text as layout:
1389          * ------------------------------------------------------
1390          * | confounder | gss header | clear msgs | krb5 header |
1391          * ------------------------------------------------------
1392          */
1393         hash_objs[0].len = ke->ke_conf_size;
1394         hash_objs[0].data = plain_out.data;
1395         hash_objs[1].len = gsshdr->len;
1396         hash_objs[1].data = gsshdr->data;
1397         hash_objs[2].len = plain_out.len - ke->ke_conf_size - sizeof(*khdr);
1398         hash_objs[2].data = plain_out.data + ke->ke_conf_size;
1399         if (krb5_make_checksum(kctx->kc_enctype, &kctx->kc_keyi,
1400                                khdr, 3, hash_objs, 0, NULL, &cksum,
1401                                gctx->hash_func))
1402                 goto out_free;
1403
1404         LASSERT(cksum.len >= ke->ke_hash_size);
1405         if (memcmp((char *)(khdr + 1) + bodysize,
1406                    cksum.data + cksum.len - ke->ke_hash_size,
1407                    ke->ke_hash_size)) {
1408                 CERROR("checksum mismatch\n");
1409                 goto out_free;
1410         }
1411
1412         msg->len =  bodysize - ke->ke_conf_size - sizeof(*khdr);
1413         memcpy(msg->data, tmpbuf + ke->ke_conf_size, msg->len);
1414
1415         major = GSS_S_COMPLETE;
1416 out_free:
1417         OBD_FREE_LARGE(tmpbuf, bodysize);
1418         rawobj_free(&cksum);
1419         return major;
1420 }
1421
1422 static
1423 __u32 gss_unwrap_bulk_kerberos(struct gss_ctx *gctx,
1424                                struct ptlrpc_bulk_desc *desc,
1425                                rawobj_t *token, int adj_nob)
1426 {
1427         struct krb5_ctx     *kctx = gctx->internal_ctx_id;
1428         struct krb5_enctype *ke = &enctypes[kctx->kc_enctype];
1429         struct krb5_header  *khdr;
1430         int                  blocksize;
1431         rawobj_t             cksum = RAWOBJ_EMPTY;
1432         rawobj_t             cipher, plain;
1433         rawobj_t             data_desc[1];
1434         int                  rc;
1435         __u32                major;
1436
1437         LASSERT(ptlrpc_is_bulk_desc_kiov(desc->bd_type));
1438         LASSERT(ke);
1439
1440         if (token->len < sizeof(*khdr)) {
1441                 CERROR("short signature: %u\n", token->len);
1442                 return GSS_S_DEFECTIVE_TOKEN;
1443         }
1444
1445         khdr = (struct krb5_header *)token->data;
1446
1447         major = verify_krb5_header(kctx, khdr, 1);
1448         if (major != GSS_S_COMPLETE) {
1449                 CERROR("bad krb5 header\n");
1450                 return major;
1451         }
1452
1453         /* block size */
1454         if (kctx->kc_enctype == ENCTYPE_ARCFOUR_HMAC) {
1455                 LASSERT(kctx->kc_keye.kb_tfm == NULL);
1456                 blocksize = 1;
1457                 LBUG();
1458         } else {
1459                 LASSERT(kctx->kc_keye.kb_tfm);
1460                 blocksize = crypto_blkcipher_blocksize(kctx->kc_keye.kb_tfm);
1461         }
1462         LASSERT(sizeof(*khdr) >= blocksize && sizeof(*khdr) % blocksize == 0);
1463
1464         /*
1465          * token format is expected as:
1466          * -----------------------------------------------
1467          * | krb5 header | head/tail cipher text | cksum |
1468          * -----------------------------------------------
1469          */
1470         if (token->len < sizeof(*khdr) + blocksize + sizeof(*khdr) +
1471             ke->ke_hash_size) {
1472                 CERROR("short token size: %u\n", token->len);
1473                 return GSS_S_DEFECTIVE_TOKEN;
1474         }
1475
1476         cipher.data = (__u8 *) (khdr + 1);
1477         cipher.len = blocksize + sizeof(*khdr);
1478         plain.data = cipher.data;
1479         plain.len = cipher.len;
1480
1481         rc = krb5_decrypt_bulk(kctx->kc_keye.kb_tfm, khdr,
1482                                desc, &cipher, &plain, adj_nob);
1483         if (rc)
1484                 return GSS_S_DEFECTIVE_TOKEN;
1485
1486         /*
1487          * verify checksum, compose clear text as layout:
1488          * ------------------------------------------
1489          * | confounder | clear pages | krb5 header |
1490          * ------------------------------------------
1491          */
1492         data_desc[0].data = plain.data;
1493         data_desc[0].len = blocksize;
1494
1495         if (krb5_make_checksum(kctx->kc_enctype, &kctx->kc_keyi,
1496                                khdr, 1, data_desc,
1497                                desc->bd_iov_count,
1498                                GET_KIOV(desc),
1499                                &cksum, gctx->hash_func))
1500                 return GSS_S_FAILURE;
1501         LASSERT(cksum.len >= ke->ke_hash_size);
1502
1503         if (memcmp(plain.data + blocksize + sizeof(*khdr),
1504                    cksum.data + cksum.len - ke->ke_hash_size,
1505                    ke->ke_hash_size)) {
1506                 CERROR("checksum mismatch\n");
1507                 rawobj_free(&cksum);
1508                 return GSS_S_BAD_SIG;
1509         }
1510
1511         rawobj_free(&cksum);
1512         return GSS_S_COMPLETE;
1513 }
1514
1515 int gss_display_kerberos(struct gss_ctx        *ctx,
1516                          char                  *buf,
1517                          int                    bufsize)
1518 {
1519         struct krb5_ctx    *kctx = ctx->internal_ctx_id;
1520         int                 written;
1521
1522         written = snprintf(buf, bufsize, "krb5 (%s)",
1523                            enctype2str(kctx->kc_enctype));
1524         return written;
1525 }
1526
1527 static struct gss_api_ops gss_kerberos_ops = {
1528         .gss_import_sec_context     = gss_import_sec_context_kerberos,
1529         .gss_copy_reverse_context   = gss_copy_reverse_context_kerberos,
1530         .gss_inquire_context        = gss_inquire_context_kerberos,
1531         .gss_get_mic                = gss_get_mic_kerberos,
1532         .gss_verify_mic             = gss_verify_mic_kerberos,
1533         .gss_wrap                   = gss_wrap_kerberos,
1534         .gss_unwrap                 = gss_unwrap_kerberos,
1535         .gss_prep_bulk              = gss_prep_bulk_kerberos,
1536         .gss_wrap_bulk              = gss_wrap_bulk_kerberos,
1537         .gss_unwrap_bulk            = gss_unwrap_bulk_kerberos,
1538         .gss_delete_sec_context     = gss_delete_sec_context_kerberos,
1539         .gss_display                = gss_display_kerberos,
1540 };
1541
1542 static struct subflavor_desc gss_kerberos_sfs[] = {
1543         {
1544                 .sf_subflavor   = SPTLRPC_SUBFLVR_KRB5N,
1545                 .sf_qop         = 0,
1546                 .sf_service     = SPTLRPC_SVC_NULL,
1547                 .sf_name        = "krb5n"
1548         },
1549         {
1550                 .sf_subflavor   = SPTLRPC_SUBFLVR_KRB5A,
1551                 .sf_qop         = 0,
1552                 .sf_service     = SPTLRPC_SVC_AUTH,
1553                 .sf_name        = "krb5a"
1554         },
1555         {
1556                 .sf_subflavor   = SPTLRPC_SUBFLVR_KRB5I,
1557                 .sf_qop         = 0,
1558                 .sf_service     = SPTLRPC_SVC_INTG,
1559                 .sf_name        = "krb5i"
1560         },
1561         {
1562                 .sf_subflavor   = SPTLRPC_SUBFLVR_KRB5P,
1563                 .sf_qop         = 0,
1564                 .sf_service     = SPTLRPC_SVC_PRIV,
1565                 .sf_name        = "krb5p"
1566         },
1567 };
1568
1569 static struct gss_api_mech gss_kerberos_mech = {
1570         /* .gm_owner uses default NULL value for THIS_MODULE */
1571         .gm_name        = "krb5",
1572         .gm_oid         = (rawobj_t)
1573                                 {9, "\052\206\110\206\367\022\001\002\002"},
1574         .gm_ops         = &gss_kerberos_ops,
1575         .gm_sf_num      = 4,
1576         .gm_sfs         = gss_kerberos_sfs,
1577 };
1578
1579 int __init init_kerberos_module(void)
1580 {
1581         int status;
1582
1583         status = lgss_mech_register(&gss_kerberos_mech);
1584         if (status)
1585                 CERROR("Failed to register kerberos gss mechanism!\n");
1586         return status;
1587 }
1588
1589 void cleanup_kerberos_module(void)
1590 {
1591         lgss_mech_unregister(&gss_kerberos_mech);
1592 }