source4/libcli/auth/gensec_krb5.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    Kerberos backend for GENSEC
   5
   6    Copyright (C) Andrew Bartlett <abartlet@samba.org> 2004
   7    Copyright (C) Andrew Tridgell 2001
   8    Copyright (C) Luke Howard 2002-2003
   9    Copyright (C) Stefan Metzmacher 2004-2005
  10
  11    This program is free software; you can redistribute it and/or modify
  12    it under the terms of the GNU General Public License as published by
  13    the Free Software Foundation; either version 2 of the License, or
  14    (at your option) any later version.
  15
  16    This program is distributed in the hope that it will be useful,
  17    but WITHOUT ANY WARRANTY; without even the implied warranty of
  18    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19    GNU General Public License for more details.
  20
  21
  22    You should have received a copy of the GNU General Public License
  23    along with this program; if not, write to the Free Software
  24    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  25 */
  26
  27 #include "includes.h"
  28 #include "system/kerberos.h"
  29 #include "system/time.h"
  30 #include "libcli/auth/kerberos.h"
  31 #include "librpc/gen_ndr/ndr_krb5pac.h"
  32 #include "auth/auth.h"
  33
  34 enum GENSEC_KRB5_STATE {
  35         GENSEC_KRB5_SERVER_START,
  36         GENSEC_KRB5_CLIENT_START,
  37         GENSEC_KRB5_CLIENT_MUTUAL_AUTH,
  38         GENSEC_KRB5_DONE
  39 };
  40
  41 struct gensec_krb5_state {
  42         DATA_BLOB session_key;
  43         DATA_BLOB pac;
  44         enum GENSEC_KRB5_STATE state_position;
  45         krb5_context context;
  46         krb5_auth_context auth_context;
  47         krb5_ccache ccache;
  48         krb5_data ticket;
  49         krb5_keyblock keyblock;
  50         char *peer_principal;
  51 };
  52
  53 #ifdef KRB5_DO_VERIFY_PAC
  54 static NTSTATUS gensec_krb5_pac_checksum(DATA_BLOB pac_data,
  55                                             struct PAC_SIGNATURE_DATA *sig,
  56                                             struct gensec_krb5_state *gensec_krb5_state,
  57                                             uint32 keyusage)
  58 {
  59         krb5_error_code ret;
  60         krb5_crypto crypto;
  61         Checksum cksum;
  62         int i;
  63
  64         cksum.cksumtype         = (CKSUMTYPE)sig->type;
  65         cksum.checksum.length   = sizeof(sig->signature);
  66         cksum.checksum.data     = sig->signature;
  67
  68
  69         ret = krb5_crypto_init(gensec_krb5_state->context,
  70                                 &gensec_krb5_state->keyblock,
  71                                 0,
  72                                 &crypto);
  73         if (ret) {
  74                 DEBUG(0,("krb5_crypto_init() failed\n"));
  75                 return NT_STATUS_FOOBAR;
  76         }
  77         for (i=0; i < 40; i++) {
  78                 keyusage = i;
  79                 ret = krb5_verify_checksum(gensec_krb5_state->context,
  80                                            crypto,
  81                                            keyusage,
  82                                            pac_data.data,
  83                                            pac_data.length,
  84                                            &cksum);
  85                 if (!ret) {
  86                         DEBUG(0,("PAC Verified: keyusage: %d\n", keyusage));
  87                         break;
  88                 }
  89         }
  90         krb5_crypto_destroy(gensec_krb5_state->context, crypto);
  91
  92         if (ret) {
  93                 DEBUG(0,("NOT verifying PAC checksums yet!\n"));
  94                 //return NT_STATUS_LOGON_FAILURE;
  95         } else {
  96                 DEBUG(0,("PAC checksums verified!\n"));
  97         }
  98
  99         return NT_STATUS_OK;
 100 }
 101 #endif
 102
 103 static NTSTATUS gensec_krb5_decode_pac(TALLOC_CTX *mem_ctx,
 104                                 struct PAC_LOGON_INFO **logon_info_out,
 105                                 DATA_BLOB blob,
 106                                 struct gensec_krb5_state *gensec_krb5_state)
 107 {
 108         NTSTATUS status;
 109         struct PAC_SIGNATURE_DATA srv_sig;
 110         struct PAC_SIGNATURE_DATA *srv_sig_ptr;
 111         struct PAC_SIGNATURE_DATA kdc_sig;
 112         struct PAC_SIGNATURE_DATA *kdc_sig_ptr;
 113         struct PAC_LOGON_INFO *logon_info = NULL;
 114         struct PAC_DATA pac_data;
 115 #ifdef KRB5_DO_VERIFY_PAC
 116         DATA_BLOB tmp_blob = data_blob(NULL, 0);
 117 #endif
 118         int i;
 119
 120         status = ndr_pull_struct_blob(&blob, mem_ctx, &pac_data,
 121                                         (ndr_pull_flags_fn_t)ndr_pull_PAC_DATA);
 122         if (!NT_STATUS_IS_OK(status)) {
 123                 DEBUG(0,("can't parse the PAC\n"));
 124                 return status;
 125         }
 126         NDR_PRINT_DEBUG(PAC_DATA, &pac_data);
 127
 128         if (pac_data.num_buffers < 3) {
 129                 /* we need logon_ingo, service_key and kdc_key */
 130                 DEBUG(0,("less than 3 PAC buffers\n"));
 131                 return NT_STATUS_FOOBAR;
 132         }
 133
 134         for (i=0; i < pac_data.num_buffers; i++) {
 135                 switch (pac_data.buffers[i].type) {
 136                         case PAC_TYPE_LOGON_INFO:
 137                                 if (!pac_data.buffers[i].info) {
 138                                         break;
 139                                 }
 140                                 logon_info = &pac_data.buffers[i].info->logon_info;
 141                                 break;
 142                         case PAC_TYPE_SRV_CHECKSUM:
 143                                 if (!pac_data.buffers[i].info) {
 144                                         break;
 145                                 }
 146                                 srv_sig_ptr = &pac_data.buffers[i].info->srv_cksum;
 147                                 srv_sig = pac_data.buffers[i].info->srv_cksum;
 148                                 break;
 149                         case PAC_TYPE_KDC_CHECKSUM:
 150                                 if (!pac_data.buffers[i].info) {
 151                                         break;
 152                                 }
 153                                 kdc_sig_ptr = &pac_data.buffers[i].info->kdc_cksum;
 154                                 kdc_sig = pac_data.buffers[i].info->kdc_cksum;
 155                                 break;
 156                         case PAC_TYPE_UNKNOWN_10:
 157                                 break;
 158                         default:
 159                                 break;
 160                 }
 161         }
 162
 163         if (!logon_info) {
 164                 DEBUG(0,("PAC no logon_info\n"));
 165                 return NT_STATUS_FOOBAR;
 166         }
 167
 168         if (!srv_sig_ptr) {
 169                 DEBUG(0,("PAC no srv_key\n"));
 170                 return NT_STATUS_FOOBAR;
 171         }
 172
 173         if (!kdc_sig_ptr) {
 174                 DEBUG(0,("PAC no kdc_key\n"));
 175                 return NT_STATUS_FOOBAR;
 176         }
 177 #ifdef KRB5_DO_VERIFY_PAC
 178         /* clear the kdc_key */
 179 /*      memset((void *)kdc_sig_ptr , '\0', sizeof(*kdc_sig_ptr));*/
 180
 181         status = ndr_push_struct_blob(&tmp_blob, mem_ctx, &pac_data,
 182                                               (ndr_push_flags_fn_t)ndr_push_PAC_DATA);
 183         if (!NT_STATUS_IS_OK(status)) {
 184                 return status;
 185         }
 186         status = ndr_pull_struct_blob(&tmp_blob, mem_ctx, &pac_data,
 187                                         (ndr_pull_flags_fn_t)ndr_pull_PAC_DATA);
 188         if (!NT_STATUS_IS_OK(status)) {
 189                 DEBUG(0,("can't parse the PAC\n"));
 190                 return status;
 191         }
 192         /*NDR_PRINT_DEBUG(PAC_DATA, &pac_data);*/
 193
 194         /* verify by kdc_key */
 195         status = gensec_krb5_pac_checksum(tmp_blob, &kdc_sig, gensec_krb5_state, 0);
 196
 197         if (!NT_STATUS_IS_OK(status)) {
 198                 return status;
 199         }
 200
 201         /* clear the service_key */
 202 /*      memset((void *)srv_sig_ptr , '\0', sizeof(*srv_sig_ptr));*/
 203
 204         status = ndr_push_struct_blob(&tmp_blob, mem_ctx, &pac_data,
 205                                               (ndr_push_flags_fn_t)ndr_push_PAC_DATA);
 206         if (!NT_STATUS_IS_OK(status)) {
 207                 return status;
 208         }
 209         status = ndr_pull_struct_blob(&tmp_blob, mem_ctx, &pac_data,
 210                                         (ndr_pull_flags_fn_t)ndr_pull_PAC_DATA);
 211         if (!NT_STATUS_IS_OK(status)) {
 212                 DEBUG(0,("can't parse the PAC\n"));
 213                 return status;
 214         }
 215         NDR_PRINT_DEBUG(PAC_DATA, &pac_data);
 216
 217         /* verify by servie_key */
 218         status = gensec_krb5_pac_checksum(tmp_blob, &srv_sig, gensec_krb5_state, 0);
 219
 220         if (!NT_STATUS_IS_OK(status)) {
 221                 return status;
 222         }
 223 #endif
 224         DEBUG(0,("account_name: %s [%s]\n",logon_info->info3.base.account_name.string, logon_info->info3.base.full_name.string));
 225         *logon_info_out = logon_info;
 226
 227         return status;
 228 }
 229
 230 static int gensec_krb5_destory(void *ptr)
 231 {
 232         struct gensec_krb5_state *gensec_krb5_state = ptr;
 233
 234         if (gensec_krb5_state->ticket.length) {
 235                 kerberos_free_data_contents(gensec_krb5_state->context, &gensec_krb5_state->ticket);
 236         }
 237         if (gensec_krb5_state->ccache) {
 238                 /* current heimdal - 0.6.3, which we need anyway, fixes segfaults here */
 239                 krb5_cc_close(gensec_krb5_state->context, gensec_krb5_state->ccache);
 240         }
 241
 242         krb5_free_keyblock_contents(gensec_krb5_state->context,
 243                                     &gensec_krb5_state->keyblock);
 244
 245         if (gensec_krb5_state->auth_context) {
 246                 krb5_auth_con_free(gensec_krb5_state->context,
 247                                    gensec_krb5_state->auth_context);
 248         }
 249
 250         if (gensec_krb5_state->context) {
 251                 krb5_free_context(gensec_krb5_state->context);
 252         }
 253         return 0;
 254 }
 255
 256 static NTSTATUS gensec_krb5_start(struct gensec_security *gensec_security)
 257 {
 258         struct gensec_krb5_state *gensec_krb5_state;
 259         krb5_error_code ret = 0;
 260
 261         gensec_krb5_state = talloc(gensec_security, struct gensec_krb5_state);
 262         if (!gensec_krb5_state) {
 263                 return NT_STATUS_NO_MEMORY;
 264         }
 265
 266         gensec_security->private_data = gensec_krb5_state;
 267
 268         initialize_krb5_error_table();
 269         gensec_krb5_state->context = NULL;
 270         gensec_krb5_state->auth_context = NULL;
 271         gensec_krb5_state->ccache = NULL;
 272         ZERO_STRUCT(gensec_krb5_state->ticket);
 273         ZERO_STRUCT(gensec_krb5_state->keyblock);
 274         gensec_krb5_state->session_key = data_blob(NULL, 0);
 275         gensec_krb5_state->pac = data_blob(NULL, 0);
 276
 277         talloc_set_destructor(gensec_krb5_state, gensec_krb5_destory);
 278
 279         ret = krb5_init_context(&gensec_krb5_state->context);
 280         if (ret) {
 281                 DEBUG(1,("gensec_krb5_start: krb5_init_context failed (%s)\n", error_message(ret)));
 282                 return NT_STATUS_INTERNAL_ERROR;
 283         }
 284
 285         if (lp_realm() && *lp_realm()) {
 286                 ret = krb5_set_default_realm(gensec_krb5_state->context, lp_realm());
 287                 if (ret) {
 288                         DEBUG(1,("gensec_krb5_start: krb5_set_default_realm failed (%s)\n", error_message(ret)));
 289                         return NT_STATUS_INTERNAL_ERROR;
 290                 }
 291         }
 292
 293         ret = krb5_auth_con_init(gensec_krb5_state->context, &gensec_krb5_state->auth_context);
 294         if (ret) {
 295                 DEBUG(1,("gensec_krb5_start: krb5_auth_con_init failed (%s)\n", error_message(ret)));
 296                 return NT_STATUS_INTERNAL_ERROR;
 297         }
 298
 299         return NT_STATUS_OK;
 300 }
 301
 302 static NTSTATUS gensec_krb5_server_start(struct gensec_security *gensec_security)
 303 {
 304         NTSTATUS nt_status;
 305         struct gensec_krb5_state *gensec_krb5_state;
 306
 307         nt_status = gensec_krb5_start(gensec_security);
 308         if (!NT_STATUS_IS_OK(nt_status)) {
 309                 return nt_status;
 310         }
 311
 312         gensec_krb5_state = gensec_security->private_data;
 313         gensec_krb5_state->state_position = GENSEC_KRB5_SERVER_START;
 314
 315         return NT_STATUS_OK;
 316 }
 317
 318 static NTSTATUS gensec_krb5_client_start(struct gensec_security *gensec_security)
 319 {
 320         struct gensec_krb5_state *gensec_krb5_state;
 321         krb5_error_code ret;
 322         NTSTATUS nt_status;
 323
 324         nt_status = gensec_krb5_start(gensec_security);
 325         if (!NT_STATUS_IS_OK(nt_status)) {
 326                 return nt_status;
 327         }
 328
 329         gensec_krb5_state = gensec_security->private_data;
 330         gensec_krb5_state->state_position = GENSEC_KRB5_CLIENT_START;
 331
 332         /* TODO: This is effecivly a static/global variable...
 333
 334            TODO: If the user set a username, we should use an in-memory CCACHE (see below)
 335         */
 336         ret = krb5_cc_default(gensec_krb5_state->context, &gensec_krb5_state->ccache);
 337         if (ret) {
 338                 DEBUG(1,("krb5_cc_default failed (%s)\n",
 339                          error_message(ret)));
 340                 return NT_STATUS_INTERNAL_ERROR;
 341         }
 342
 343         while (1) {
 344                 if (gensec_security->target.principal) {
 345                         DEBUG(5, ("Finding ticket for target [%s]\n", gensec_security->target.principal));
 346                         ret = ads_krb5_mk_req(gensec_krb5_state->context,
 347                                               &gensec_krb5_state->auth_context,
 348                                               AP_OPTS_USE_SUBKEY | AP_OPTS_MUTUAL_REQUIRED,
 349                                               gensec_security->target.principal,
 350                                               gensec_krb5_state->ccache,
 351                                               &gensec_krb5_state->ticket);
 352                 } else {
 353                         krb5_data in_data;
 354                         const char *hostname = gensec_get_target_hostname(gensec_security);
 355                         if (!hostname) {
 356                                 DEBUG(1, ("Could not determine hostname for target computer, cannot use kerberos\n"));
 357                                 return NT_STATUS_ACCESS_DENIED;
 358                         }
 359
 360                         in_data.length = 0;
 361
 362                         ret = krb5_mk_req(gensec_krb5_state->context,
 363                                           &gensec_krb5_state->auth_context,
 364                                           AP_OPTS_USE_SUBKEY | AP_OPTS_MUTUAL_REQUIRED,
 365                                           gensec_get_target_service(gensec_security),
 366                                           hostname,
 367                                           &in_data, gensec_krb5_state->ccache,
 368                                           &gensec_krb5_state->ticket);
 369
 370                 }
 371                 switch (ret) {
 372                 case 0:
 373                         return NT_STATUS_OK;
 374                 case KRB5KDC_ERR_S_PRINCIPAL_UNKNOWN:
 375                         DEBUG(3, ("Server is not registered with our KDC: %s\n",
 376                                   error_message(ret)));
 377                         return NT_STATUS_ACCESS_DENIED;
 378                 case KRB5KDC_ERR_PREAUTH_FAILED:
 379                 case KRB5KRB_AP_ERR_TKT_EXPIRED:
 380                 case KRB5_CC_END:
 381                 {
 382                         DEBUG(3, ("kerberos (mk_req) failed: %s\n",
 383                                   error_message(ret)));
 384                         /* fall down to remaining code */
 385                 }
 386                 /* just don't print a message for these really ordinary messages */
 387                 case KRB5_FCC_NOFILE:
 388                 case KRB5_CC_NOTFOUND:
 389                 case ENOENT:
 390                 {
 391                         char *password;
 392                         char *ccache_string;
 393                         time_t kdc_time = 0;
 394                         nt_status = gensec_get_password(gensec_security,
 395                                                         gensec_security,
 396                                                         &password);
 397                         if (!NT_STATUS_IS_OK(nt_status)) {
 398                                 return nt_status;
 399                         }
 400
 401                         /* this string should be unique */
 402                         ccache_string = talloc_asprintf(gensec_krb5_state, "MEMORY:%s:%s:%s",
 403                                                         gensec_get_client_principal(gensec_security, gensec_krb5_state),
 404                                                         gensec_get_target_principal(gensec_security),
 405                                                         generate_random_str(gensec_krb5_state, 16));
 406
 407                         ret = krb5_cc_resolve(gensec_krb5_state->context, ccache_string, &gensec_krb5_state->ccache);
 408                         if (ret) {
 409                                 DEBUG(1,("failed to generate a new krb5 keytab (%s): %s\n",
 410                                          ccache_string,
 411                                          error_message(ret)));
 412                                 return NT_STATUS_INTERNAL_ERROR;
 413                         }
 414
 415                         ret = kerberos_kinit_password_cc(gensec_krb5_state->context, gensec_krb5_state->ccache,
 416                                                       gensec_get_client_principal(gensec_security, gensec_krb5_state),
 417                                                       password, NULL, &kdc_time);
 418
 419                         /* cope with ticket being in the future due to clock skew */
 420                         if ((unsigned)kdc_time > time(NULL)) {
 421                                 time_t t = time(NULL);
 422                                 int time_offset =(unsigned)kdc_time-t;
 423                                 DEBUG(4,("Advancing clock by %d seconds to cope with clock skew\n", time_offset));
 424                                 krb5_set_real_time(gensec_krb5_state->context, t + time_offset + 1, 0);
 425                         }
 426
 427                         if (ret) {
 428                                 DEBUG(1,("kinit failed (%s)\n",
 429                                          error_message(ret)));
 430                                 return NT_STATUS_WRONG_PASSWORD;
 431                         }
 432                         break;
 433                 }
 434                 default:
 435                         DEBUG(0, ("kerberos: %s\n",
 436                                   error_message(ret)));
 437                         return NT_STATUS_UNSUCCESSFUL;
 438                 }
 439         }
 440 }
 441
 442
 443 /**
 444  * Next state function for the Krb5 GENSEC mechanism
 445  *
 446  * @param gensec_krb5_state KRB5 State
 447  * @param out_mem_ctx The TALLOC_CTX for *out to be allocated on
 448  * @param in The request, as a DATA_BLOB
 449  * @param out The reply, as an talloc()ed DATA_BLOB, on *out_mem_ctx
 450  * @return Error, MORE_PROCESSING_REQUIRED if a reply is sent,
 451  *                or NT_STATUS_OK if the user is authenticated.
 452  */
 453
 454 static NTSTATUS gensec_krb5_update(struct gensec_security *gensec_security,
 455                                    TALLOC_CTX *out_mem_ctx,
 456                                    const DATA_BLOB in, DATA_BLOB *out)
 457 {
 458         struct gensec_krb5_state *gensec_krb5_state = gensec_security->private_data;
 459         krb5_error_code ret = 0;
 460         DATA_BLOB pac;
 461         NTSTATUS nt_status;
 462
 463         switch (gensec_krb5_state->state_position) {
 464         case GENSEC_KRB5_CLIENT_START:
 465         {
 466                 if (ret) {
 467                         DEBUG(1,("ads_krb5_mk_req (request ticket) failed (%s)\n",
 468                                  error_message(ret)));
 469                         nt_status = NT_STATUS_LOGON_FAILURE;
 470                 } else {
 471                         DATA_BLOB unwrapped_out;
 472
 473 #ifndef GENSEC_SEND_UNWRAPPED_KRB5 /* This should be a switch for the torture code to set */
 474                         unwrapped_out = data_blob_talloc(out_mem_ctx, gensec_krb5_state->ticket.data, gensec_krb5_state->ticket.length);
 475
 476                         /* wrap that up in a nice GSS-API wrapping */
 477                         *out = gensec_gssapi_gen_krb5_wrap(out_mem_ctx, &unwrapped_out, TOK_ID_KRB_AP_REQ);
 478 #else
 479                         *out = data_blob_talloc(out_mem_ctx, gensec_krb5_state->ticket.data, gensec_krb5_state->ticket.length);
 480 #endif
 481                         gensec_krb5_state->state_position = GENSEC_KRB5_CLIENT_MUTUAL_AUTH;
 482                         nt_status = NT_STATUS_MORE_PROCESSING_REQUIRED;
 483                 }
 484
 485                 return nt_status;
 486         }
 487
 488         case GENSEC_KRB5_CLIENT_MUTUAL_AUTH:
 489         {
 490                 krb5_data inbuf;
 491                 krb5_ap_rep_enc_part *repl = NULL;
 492                 uint8_t tok_id[2];
 493                 DATA_BLOB unwrapped_in;
 494
 495                 if (!gensec_gssapi_parse_krb5_wrap(out_mem_ctx, &in, &unwrapped_in, tok_id)) {
 496                         DEBUG(1,("gensec_gssapi_parse_krb5_wrap(mutual authentication) failed to parse\n"));
 497                         dump_data_pw("Mutual authentication message:\n", in.data, in.length);
 498                         return NT_STATUS_INVALID_PARAMETER;
 499                 }
 500                 /* TODO: check the tok_id */
 501
 502                 inbuf.data = unwrapped_in.data;
 503                 inbuf.length = unwrapped_in.length;
 504                 ret = krb5_rd_rep(gensec_krb5_state->context,
 505                                   gensec_krb5_state->auth_context,
 506                                   &inbuf, &repl);
 507                 if (ret) {
 508                         DEBUG(1,("krb5_rd_rep (mutual authentication) failed (%s)\n",
 509                                  error_message(ret)));
 510                         dump_data_pw("Mutual authentication message:\n", inbuf.data, inbuf.length);
 511                         nt_status = NT_STATUS_ACCESS_DENIED;
 512                 } else {
 513                         *out = data_blob(NULL, 0);
 514                         nt_status = NT_STATUS_OK;
 515                         gensec_krb5_state->state_position = GENSEC_KRB5_DONE;
 516                 }
 517                 if (repl) {
 518                         krb5_free_ap_rep_enc_part(gensec_krb5_state->context, repl);
 519                 }
 520                 return nt_status;
 521         }
 522
 523         case GENSEC_KRB5_SERVER_START:
 524         {
 525                 char *principal;
 526                 DATA_BLOB unwrapped_in;
 527                 DATA_BLOB unwrapped_out = data_blob(NULL, 0);
 528                 uint8_t tok_id[2];
 529
 530                 if (!in.data) {
 531                         *out = unwrapped_out;
 532                         return NT_STATUS_MORE_PROCESSING_REQUIRED;
 533                 }
 534
 535                 /* Parse the GSSAPI wrapping, if it's there... (win2k3 allows it to be omited) */
 536                 if (!gensec_gssapi_parse_krb5_wrap(out_mem_ctx, &in, &unwrapped_in, tok_id)) {
 537                         nt_status = ads_verify_ticket(out_mem_ctx,
 538                                                       gensec_krb5_state->context,
 539                                                       gensec_krb5_state->auth_context,
 540                                                       lp_realm(),
 541                                                       gensec_get_target_service(gensec_security), &in,
 542                                                       &principal, &pac, &unwrapped_out,
 543                                                       &gensec_krb5_state->keyblock);
 544                 } else {
 545                         /* TODO: check the tok_id */
 546                         nt_status = ads_verify_ticket(out_mem_ctx,
 547                                                       gensec_krb5_state->context,
 548                                                       gensec_krb5_state->auth_context,
 549                                                       lp_realm(),
 550                                                       gensec_get_target_service(gensec_security),
 551                                                       &unwrapped_in,
 552                                                       &principal, &pac, &unwrapped_out,
 553                                                       &gensec_krb5_state->keyblock);
 554                 }
 555
 556                 if (!NT_STATUS_IS_OK(nt_status)) {
 557                         return nt_status;
 558                 }
 559
 560                 if (pac.data) {
 561                         gensec_krb5_state->pac = data_blob_talloc_reference(gensec_krb5_state, &pac);
 562                 }
 563
 564                 if (NT_STATUS_IS_OK(nt_status)) {
 565                         gensec_krb5_state->state_position = GENSEC_KRB5_DONE;
 566                         /* wrap that up in a nice GSS-API wrapping */
 567 #ifndef GENSEC_SEND_UNWRAPPED_KRB5
 568                         *out = gensec_gssapi_gen_krb5_wrap(out_mem_ctx, &unwrapped_out, TOK_ID_KRB_AP_REP);
 569 #else
 570                         *out = unwrapped_out;
 571 #endif
 572                         gensec_krb5_state->peer_principal = talloc_steal(gensec_krb5_state, principal);
 573                 }
 574                 return nt_status;
 575         }
 576         case GENSEC_KRB5_DONE:
 577                 return NT_STATUS_OK;
 578         }
 579
 580         return NT_STATUS_INVALID_PARAMETER;
 581 }
 582
 583 static NTSTATUS gensec_krb5_session_key(struct gensec_security *gensec_security,
 584                                            DATA_BLOB *session_key)
 585 {
 586         struct gensec_krb5_state *gensec_krb5_state = gensec_security->private_data;
 587         krb5_context context = gensec_krb5_state->context;
 588         krb5_auth_context auth_context = gensec_krb5_state->auth_context;
 589         krb5_keyblock *skey;
 590         krb5_error_code err;
 591
 592         if (gensec_krb5_state->session_key.data) {
 593                 *session_key = gensec_krb5_state->session_key;
 594                 return NT_STATUS_OK;
 595         }
 596
 597         switch (gensec_security->gensec_role) {
 598         case GENSEC_CLIENT:
 599                 err = krb5_auth_con_getlocalsubkey(context, auth_context, &skey);
 600                 break;
 601         case GENSEC_SERVER:
 602                 err = krb5_auth_con_getremotesubkey(context, auth_context, &skey);
 603                 break;
 604         }
 605         if (err == 0 && skey != NULL) {
 606                 DEBUG(10, ("Got KRB5 session key of length %d\n",  KRB5_KEY_LENGTH(skey)));
 607                 gensec_krb5_state->session_key = data_blob_talloc(gensec_krb5_state,
 608                                                 KRB5_KEY_DATA(skey), KRB5_KEY_LENGTH(skey));
 609                 *session_key = gensec_krb5_state->session_key;
 610                 dump_data_pw("KRB5 Session Key:\n", session_key->data, session_key->length);
 611
 612                 krb5_free_keyblock(context, skey);
 613                 return NT_STATUS_OK;
 614         } else {
 615                 DEBUG(10, ("KRB5 error getting session key %d\n", err));
 616                 return NT_STATUS_NO_USER_SESSION_KEY;
 617         }
 618 }
 619
 620 static NTSTATUS gensec_krb5_session_info(struct gensec_security *gensec_security,
 621                                          struct auth_session_info **_session_info)
 622 {
 623         NTSTATUS nt_status;
 624         struct gensec_krb5_state *gensec_krb5_state = gensec_security->private_data;
 625         struct auth_serversupplied_info *server_info = NULL;
 626         struct auth_session_info *session_info = NULL;
 627         struct PAC_LOGON_INFO *logon_info;
 628         char *p;
 629         char *principal;
 630         const char *account_name;
 631         const char *realm;
 632
 633         principal = talloc_strdup(gensec_krb5_state, gensec_krb5_state->peer_principal);
 634         NT_STATUS_HAVE_NO_MEMORY(principal);
 635
 636         p = strchr(principal, '@');
 637         if (p) {
 638                 *p = '\0';
 639                 p++;
 640                 realm = p;
 641         } else {
 642                 realm = lp_realm();
 643         }
 644         account_name = principal;
 645
 646         /* decode and verify the pac */
 647         nt_status = gensec_krb5_decode_pac(gensec_krb5_state, &logon_info, gensec_krb5_state->pac,
 648                                            gensec_krb5_state);
 649
 650         /* IF we have the PAC - otherwise we need to get this
 651          * data from elsewere - local ldb, or (TODO) lookup of some
 652          * kind...
 653          *
 654          * when heimdal can generate the PAC, we should fail if there's
 655          * no PAC present
 656          */
 657
 658         if (NT_STATUS_IS_OK(nt_status)) {
 659                 union netr_Validation validation;
 660                 validation.sam3 = &logon_info->info3;
 661                 nt_status = make_server_info_netlogon_validation(gensec_krb5_state,
 662                                                                  account_name,
 663                                                                  3, &validation,
 664                                                                  &server_info);
 665                 talloc_free(principal);
 666                 NT_STATUS_NOT_OK_RETURN(nt_status);
 667         } else {
 668                 DATA_BLOB user_sess_key = data_blob(NULL, 0);
 669                 DATA_BLOB lm_sess_key = data_blob(NULL, 0);
 670                 /* TODO: should we pass the krb5 session key in here? */
 671                 nt_status = sam_get_server_info(gensec_krb5_state, account_name, realm,
 672                                                 user_sess_key, lm_sess_key,
 673                                                 &server_info);
 674                 talloc_free(principal);
 675                 NT_STATUS_NOT_OK_RETURN(nt_status);
 676         }
 677
 678         /* references the server_info into the session_info */
 679         nt_status = auth_generate_session_info(gensec_krb5_state, server_info, &session_info);
 680         talloc_free(server_info);
 681         NT_STATUS_NOT_OK_RETURN(nt_status);
 682
 683         nt_status = gensec_krb5_session_key(gensec_security, &session_info->session_key);
 684         NT_STATUS_NOT_OK_RETURN(nt_status);
 685
 686         *_session_info = session_info;
 687
 688         return NT_STATUS_OK;
 689 }
 690
 691 static BOOL gensec_krb5_have_feature(struct gensec_security *gensec_security,
 692                                      uint32_t feature)
 693 {
 694         if (feature & GENSEC_FEATURE_SESSION_KEY) {
 695                 return True;
 696         }
 697
 698         return False;
 699 }
 700
 701
 702 static const struct gensec_security_ops gensec_krb5_security_ops = {
 703         .name           = "krb5",
 704         .auth_type      = DCERPC_AUTH_TYPE_KRB5,
 705         .oid            = GENSEC_OID_KERBEROS5,
 706         .client_start   = gensec_krb5_client_start,
 707         .server_start   = gensec_krb5_server_start,
 708         .update         = gensec_krb5_update,
 709         .session_key    = gensec_krb5_session_key,
 710         .session_info   = gensec_krb5_session_info,
 711         .have_feature   = gensec_krb5_have_feature,
 712         .enabled        = False
 713 };
 714
 715 static const struct gensec_security_ops gensec_ms_krb5_security_ops = {
 716         .name           = "ms_krb5",
 717         .auth_type      = DCERPC_AUTH_TYPE_KRB5,
 718         .oid            = GENSEC_OID_KERBEROS5_OLD,
 719         .client_start   = gensec_krb5_client_start,
 720         .server_start   = gensec_krb5_server_start,
 721         .update         = gensec_krb5_update,
 722         .session_key    = gensec_krb5_session_key,
 723         .session_info   = gensec_krb5_session_info,
 724         .have_feature   = gensec_krb5_have_feature,
 725         .enabled        = False
 726 };
 727
 728
 729 NTSTATUS gensec_krb5_init(void)
 730 {
 731         NTSTATUS ret;
 732
 733         ret = gensec_register(&gensec_krb5_security_ops);
 734         if (!NT_STATUS_IS_OK(ret)) {
 735                 DEBUG(0,("Failed to register '%s' gensec backend!\n",
 736                         gensec_krb5_security_ops.name));
 737                 return ret;
 738         }
 739
 740         ret = gensec_register(&gensec_ms_krb5_security_ops);
 741         if (!NT_STATUS_IS_OK(ret)) {
 742                 DEBUG(0,("Failed to register '%s' gensec backend!\n",
 743                         gensec_krb5_security_ops.name));
 744                 return ret;
 745         }
 746
 747         return ret;
 748 }