source4/auth/gensec/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 "system/network.h"
  31 #include "auth/kerberos/kerberos.h"
  32 #include "librpc/gen_ndr/ndr_krb5pac.h"
  33 #include "auth/auth.h"
  34
  35 enum GENSEC_KRB5_STATE {
  36         GENSEC_KRB5_SERVER_START,
  37         GENSEC_KRB5_CLIENT_START,
  38         GENSEC_KRB5_CLIENT_MUTUAL_AUTH,
  39         GENSEC_KRB5_DONE
  40 };
  41
  42 struct gensec_krb5_state {
  43         DATA_BLOB session_key;
  44         DATA_BLOB pac;
  45         enum GENSEC_KRB5_STATE state_position;
  46         krb5_context context;
  47         krb5_auth_context auth_context;
  48         krb5_ccache ccache;
  49         krb5_data ticket;
  50         krb5_keyblock keyblock;
  51         char *peer_principal;
  52 };
  53
  54 #ifdef KRB5_DO_VERIFY_PAC
  55 static NTSTATUS gensec_krb5_pac_checksum(DATA_BLOB pac_data,
  56                                             struct PAC_SIGNATURE_DATA *sig,
  57                                             struct gensec_krb5_state *gensec_krb5_state,
  58                                             uint32 keyusage)
  59 {
  60         krb5_error_code ret;
  61         krb5_crypto crypto;
  62         Checksum cksum;
  63         int i;
  64
  65         cksum.cksumtype         = (CKSUMTYPE)sig->type;
  66         cksum.checksum.length   = sizeof(sig->signature);
  67         cksum.checksum.data     = sig->signature;
  68
  69
  70         ret = krb5_crypto_init(gensec_krb5_state->context,
  71                                 &gensec_krb5_state->keyblock,
  72                                 0,
  73                                 &crypto);
  74         if (ret) {
  75                 DEBUG(0,("krb5_crypto_init() failed\n"));
  76                 return NT_STATUS_FOOBAR;
  77         }
  78         for (i=0; i < 40; i++) {
  79                 keyusage = i;
  80                 ret = krb5_verify_checksum(gensec_krb5_state->context,
  81                                            crypto,
  82                                            keyusage,
  83                                            pac_data.data,
  84                                            pac_data.length,
  85                                            &cksum);
  86                 if (!ret) {
  87                         DEBUG(0,("PAC Verified: keyusage: %d\n", keyusage));
  88                         break;
  89                 }
  90         }
  91         krb5_crypto_destroy(gensec_krb5_state->context, crypto);
  92
  93         if (ret) {
  94                 DEBUG(0,("NOT verifying PAC checksums yet!\n"));
  95                 //return NT_STATUS_LOGON_FAILURE;
  96         } else {
  97                 DEBUG(0,("PAC checksums verified!\n"));
  98         }
  99
 100         return NT_STATUS_OK;
 101 }
 102 #endif
 103
 104 static NTSTATUS gensec_krb5_decode_pac(TALLOC_CTX *mem_ctx,
 105                                 struct PAC_LOGON_INFO **logon_info_out,
 106                                 DATA_BLOB blob,
 107                                 struct gensec_krb5_state *gensec_krb5_state)
 108 {
 109         NTSTATUS status;
 110         struct PAC_SIGNATURE_DATA srv_sig;
 111         struct PAC_SIGNATURE_DATA *srv_sig_ptr;
 112         struct PAC_SIGNATURE_DATA kdc_sig;
 113         struct PAC_SIGNATURE_DATA *kdc_sig_ptr;
 114         struct PAC_LOGON_INFO *logon_info = NULL;
 115         struct PAC_DATA pac_data;
 116 #ifdef KRB5_DO_VERIFY_PAC
 117         DATA_BLOB tmp_blob = data_blob(NULL, 0);
 118 #endif
 119         int i;
 120
 121         status = ndr_pull_struct_blob(&blob, mem_ctx, &pac_data,
 122                                         (ndr_pull_flags_fn_t)ndr_pull_PAC_DATA);
 123         if (!NT_STATUS_IS_OK(status)) {
 124                 DEBUG(0,("can't parse the PAC\n"));
 125                 return status;
 126         }
 127         NDR_PRINT_DEBUG(PAC_DATA, &pac_data);
 128
 129         if (pac_data.num_buffers < 3) {
 130                 /* we need logon_ingo, service_key and kdc_key */
 131                 DEBUG(0,("less than 3 PAC buffers\n"));
 132                 return NT_STATUS_FOOBAR;
 133         }
 134
 135         for (i=0; i < pac_data.num_buffers; i++) {
 136                 switch (pac_data.buffers[i].type) {
 137                         case PAC_TYPE_LOGON_INFO:
 138                                 if (!pac_data.buffers[i].info) {
 139                                         break;
 140                                 }
 141                                 logon_info = &pac_data.buffers[i].info->logon_info;
 142                                 break;
 143                         case PAC_TYPE_SRV_CHECKSUM:
 144                                 if (!pac_data.buffers[i].info) {
 145                                         break;
 146                                 }
 147                                 srv_sig_ptr = &pac_data.buffers[i].info->srv_cksum;
 148                                 srv_sig = pac_data.buffers[i].info->srv_cksum;
 149                                 break;
 150                         case PAC_TYPE_KDC_CHECKSUM:
 151                                 if (!pac_data.buffers[i].info) {
 152                                         break;
 153                                 }
 154                                 kdc_sig_ptr = &pac_data.buffers[i].info->kdc_cksum;
 155                                 kdc_sig = pac_data.buffers[i].info->kdc_cksum;
 156                                 break;
 157                         case PAC_TYPE_UNKNOWN_10:
 158                                 break;
 159                         default:
 160                                 break;
 161                 }
 162         }
 163
 164         if (!logon_info) {
 165                 DEBUG(0,("PAC no logon_info\n"));
 166                 return NT_STATUS_FOOBAR;
 167         }
 168
 169         if (!srv_sig_ptr) {
 170                 DEBUG(0,("PAC no srv_key\n"));
 171                 return NT_STATUS_FOOBAR;
 172         }
 173
 174         if (!kdc_sig_ptr) {
 175                 DEBUG(0,("PAC no kdc_key\n"));
 176                 return NT_STATUS_FOOBAR;
 177         }
 178 #ifdef KRB5_DO_VERIFY_PAC
 179         /* clear the kdc_key */
 180 /*      memset((void *)kdc_sig_ptr , '\0', sizeof(*kdc_sig_ptr));*/
 181
 182         status = ndr_push_struct_blob(&tmp_blob, mem_ctx, &pac_data,
 183                                               (ndr_push_flags_fn_t)ndr_push_PAC_DATA);
 184         if (!NT_STATUS_IS_OK(status)) {
 185                 return status;
 186         }
 187         status = ndr_pull_struct_blob(&tmp_blob, mem_ctx, &pac_data,
 188                                         (ndr_pull_flags_fn_t)ndr_pull_PAC_DATA);
 189         if (!NT_STATUS_IS_OK(status)) {
 190                 DEBUG(0,("can't parse the PAC\n"));
 191                 return status;
 192         }
 193         /*NDR_PRINT_DEBUG(PAC_DATA, &pac_data);*/
 194
 195         /* verify by kdc_key */
 196         status = gensec_krb5_pac_checksum(tmp_blob, &kdc_sig, gensec_krb5_state, 0);
 197
 198         if (!NT_STATUS_IS_OK(status)) {
 199                 return status;
 200         }
 201
 202         /* clear the service_key */
 203 /*      memset((void *)srv_sig_ptr , '\0', sizeof(*srv_sig_ptr));*/
 204
 205         status = ndr_push_struct_blob(&tmp_blob, mem_ctx, &pac_data,
 206                                               (ndr_push_flags_fn_t)ndr_push_PAC_DATA);
 207         if (!NT_STATUS_IS_OK(status)) {
 208                 return status;
 209         }
 210         status = ndr_pull_struct_blob(&tmp_blob, mem_ctx, &pac_data,
 211                                         (ndr_pull_flags_fn_t)ndr_pull_PAC_DATA);
 212         if (!NT_STATUS_IS_OK(status)) {
 213                 DEBUG(0,("can't parse the PAC\n"));
 214                 return status;
 215         }
 216         NDR_PRINT_DEBUG(PAC_DATA, &pac_data);
 217
 218         /* verify by servie_key */
 219         status = gensec_krb5_pac_checksum(tmp_blob, &srv_sig, gensec_krb5_state, 0);
 220
 221         if (!NT_STATUS_IS_OK(status)) {
 222                 return status;
 223         }
 224 #endif
 225         DEBUG(0,("account_name: %s [%s]\n",logon_info->info3.base.account_name.string, logon_info->info3.base.full_name.string));
 226         *logon_info_out = logon_info;
 227
 228         return status;
 229 }
 230
 231 static int gensec_krb5_destory(void *ptr)
 232 {
 233         struct gensec_krb5_state *gensec_krb5_state = ptr;
 234
 235         if (gensec_krb5_state->ticket.length) {
 236                 kerberos_free_data_contents(gensec_krb5_state->context, &gensec_krb5_state->ticket);
 237         }
 238         if (gensec_krb5_state->ccache) {
 239                 /* current heimdal - 0.6.3, which we need anyway, fixes segfaults here */
 240                 krb5_cc_close(gensec_krb5_state->context, gensec_krb5_state->ccache);
 241         }
 242
 243         krb5_free_keyblock_contents(gensec_krb5_state->context,
 244                                     &gensec_krb5_state->keyblock);
 245
 246         if (gensec_krb5_state->auth_context) {
 247                 krb5_auth_con_free(gensec_krb5_state->context,
 248                                    gensec_krb5_state->auth_context);
 249         }
 250
 251         if (gensec_krb5_state->context) {
 252                 krb5_free_context(gensec_krb5_state->context);
 253         }
 254         return 0;
 255 }
 256
 257 static NTSTATUS gensec_krb5_start(struct gensec_security *gensec_security)
 258 {
 259         struct gensec_krb5_state *gensec_krb5_state;
 260         krb5_error_code ret = 0;
 261
 262         gensec_krb5_state = talloc(gensec_security, struct gensec_krb5_state);
 263         if (!gensec_krb5_state) {
 264                 return NT_STATUS_NO_MEMORY;
 265         }
 266
 267         gensec_security->private_data = gensec_krb5_state;
 268
 269         initialize_krb5_error_table();
 270         gensec_krb5_state->context = NULL;
 271         gensec_krb5_state->auth_context = NULL;
 272         gensec_krb5_state->ccache = NULL;
 273         ZERO_STRUCT(gensec_krb5_state->ticket);
 274         ZERO_STRUCT(gensec_krb5_state->keyblock);
 275         gensec_krb5_state->session_key = data_blob(NULL, 0);
 276         gensec_krb5_state->pac = data_blob(NULL, 0);
 277
 278         talloc_set_destructor(gensec_krb5_state, gensec_krb5_destory);
 279
 280         ret = krb5_init_context(&gensec_krb5_state->context);
 281         if (ret) {
 282                 DEBUG(1,("gensec_krb5_start: krb5_init_context failed (%s)\n", error_message(ret)));
 283                 return NT_STATUS_INTERNAL_ERROR;
 284         }
 285
 286         if (lp_realm() && *lp_realm()) {
 287                 ret = krb5_set_default_realm(gensec_krb5_state->context, lp_realm());
 288                 if (ret) {
 289                         DEBUG(1,("gensec_krb5_start: krb5_set_default_realm failed (%s)\n", error_message(ret)));
 290                         return NT_STATUS_INTERNAL_ERROR;
 291                 }
 292         }
 293
 294         ret = krb5_auth_con_init(gensec_krb5_state->context, &gensec_krb5_state->auth_context);
 295         if (ret) {
 296                 DEBUG(1,("gensec_krb5_start: krb5_auth_con_init failed (%s)\n", error_message(ret)));
 297                 return NT_STATUS_INTERNAL_ERROR;
 298         }
 299
 300         return NT_STATUS_OK;
 301 }
 302
 303 static NTSTATUS gensec_krb5_server_start(struct gensec_security *gensec_security)
 304 {
 305         NTSTATUS nt_status;
 306         struct gensec_krb5_state *gensec_krb5_state;
 307
 308         nt_status = gensec_krb5_start(gensec_security);
 309         if (!NT_STATUS_IS_OK(nt_status)) {
 310                 return nt_status;
 311         }
 312
 313         gensec_krb5_state = gensec_security->private_data;
 314         gensec_krb5_state->state_position = GENSEC_KRB5_SERVER_START;
 315
 316         return NT_STATUS_OK;
 317 }
 318
 319 static NTSTATUS gensec_krb5_client_start(struct gensec_security *gensec_security)
 320 {
 321         struct gensec_krb5_state *gensec_krb5_state;
 322         krb5_error_code ret;
 323         NTSTATUS nt_status;
 324         const char *hostname = gensec_get_target_hostname(gensec_security);
 325         if (!hostname) {
 326                 DEBUG(1, ("Could not determine hostname for target computer, cannot use kerberos\n"));
 327                 return NT_STATUS_ACCESS_DENIED;
 328         }
 329
 330         nt_status = gensec_krb5_start(gensec_security);
 331         if (!NT_STATUS_IS_OK(nt_status)) {
 332                 return nt_status;
 333         }
 334
 335         gensec_krb5_state = gensec_security->private_data;
 336         gensec_krb5_state->state_position = GENSEC_KRB5_CLIENT_START;
 337
 338         /* TODO: This is effecivly a static/global variable...
 339
 340            TODO: If the user set a username, we should use an in-memory CCACHE (see below)
 341         */
 342         ret = krb5_cc_default(gensec_krb5_state->context, &gensec_krb5_state->ccache);
 343         if (ret) {
 344                 DEBUG(1,("krb5_cc_default failed (%s)\n",
 345                          error_message(ret)));
 346                 return NT_STATUS_INTERNAL_ERROR;
 347         }
 348
 349         while (1) {
 350                 {
 351                         krb5_data in_data;
 352                         in_data.length = 0;
 353
 354                         ret = krb5_mk_req(gensec_krb5_state->context,
 355                                           &gensec_krb5_state->auth_context,
 356                                           AP_OPTS_USE_SUBKEY | AP_OPTS_MUTUAL_REQUIRED,
 357                                           gensec_get_target_service(gensec_security),
 358                                           hostname,
 359                                           &in_data, gensec_krb5_state->ccache,
 360                                           &gensec_krb5_state->ticket);
 361
 362                 }
 363                 switch (ret) {
 364                 case 0:
 365                         return NT_STATUS_OK;
 366                 case KRB5KDC_ERR_S_PRINCIPAL_UNKNOWN:
 367                         DEBUG(3, ("Server [%s] is not registered with our KDC: %s\n",
 368                                   hostname, error_message(ret)));
 369                         return NT_STATUS_ACCESS_DENIED;
 370                 case KRB5KDC_ERR_PREAUTH_FAILED:
 371                 case KRB5KRB_AP_ERR_TKT_EXPIRED:
 372                 case KRB5_CC_END:
 373                         /* Too much clock skew - we will need to kinit to re-skew the clock */
 374                 case KRB5KRB_AP_ERR_SKEW:
 375                 case KRB5_KDCREP_SKEW:
 376                 {
 377                         DEBUG(3, ("kerberos (mk_req) failed: %s\n",
 378                                   error_message(ret)));
 379                         /* fall down to remaining code */
 380                 }
 381
 382
 383                 /* just don't print a message for these really ordinary messages */
 384                 case KRB5_FCC_NOFILE:
 385                 case KRB5_CC_NOTFOUND:
 386                 case ENOENT:
 387
 388                 {
 389                         const char *password;
 390                         char *ccache_string;
 391                         time_t kdc_time = 0;
 392                         password = cli_credentials_get_password(gensec_security->credentials);
 393                         if (!NT_STATUS_IS_OK(nt_status)) {
 394                                 return nt_status;
 395                         }
 396
 397                         /* this string should be unique */
 398                         ccache_string = talloc_asprintf(gensec_krb5_state, "MEMORY:%s:%s:%s",
 399                                                         cli_credentials_get_principal(gensec_security->credentials, gensec_krb5_state),
 400                                                         gensec_get_target_hostname(gensec_security),
 401                                                         generate_random_str(gensec_krb5_state, 16));
 402
 403                         ret = krb5_cc_resolve(gensec_krb5_state->context, ccache_string, &gensec_krb5_state->ccache);
 404                         if (ret) {
 405                                 DEBUG(1,("failed to generate a new krb5 keytab (%s): %s\n",
 406                                          ccache_string,
 407                                          error_message(ret)));
 408                                 return NT_STATUS_INTERNAL_ERROR;
 409                         }
 410
 411                         ret = kerberos_kinit_password_cc(gensec_krb5_state->context, gensec_krb5_state->ccache,
 412                                                          cli_credentials_get_principal(gensec_security->credentials, gensec_krb5_state),
 413                                                          password, NULL, &kdc_time);
 414
 415                         /* cope with ticket being in the future due to clock skew */
 416                         if ((unsigned)kdc_time > time(NULL)) {
 417                                 time_t t = time(NULL);
 418                                 int time_offset =(unsigned)kdc_time-t;
 419                                 DEBUG(4,("Advancing clock by %d seconds to cope with clock skew\n", time_offset));
 420                                 krb5_set_real_time(gensec_krb5_state->context, t + time_offset + 1, 0);
 421                                 break;
 422                         }
 423
 424                         if (ret == KRB5KRB_AP_ERR_SKEW || ret == KRB5_KDCREP_SKEW) {
 425                                 DEBUG(1,("kinit for %s failed (%s)\n",
 426                                          cli_credentials_get_principal(gensec_security->credentials, gensec_krb5_state),
 427                                          error_message(ret)));
 428                                 return NT_STATUS_TIME_DIFFERENCE_AT_DC;
 429                         }
 430                         if (ret) {
 431                                 DEBUG(1,("kinit for %s failed (%s)\n",
 432                                          cli_credentials_get_principal(gensec_security->credentials, gensec_krb5_state),
 433                                          error_message(ret)));
 434                                 return NT_STATUS_WRONG_PASSWORD;
 435                         }
 436                         break;
 437                 }
 438                 default:
 439                         DEBUG(0, ("kerberos: %s\n",
 440                                   error_message(ret)));
 441                         return NT_STATUS_UNSUCCESSFUL;
 442                 }
 443         }
 444 }
 445
 446
 447 /**
 448  * Next state function for the Krb5 GENSEC mechanism
 449  *
 450  * @param gensec_krb5_state KRB5 State
 451  * @param out_mem_ctx The TALLOC_CTX for *out to be allocated on
 452  * @param in The request, as a DATA_BLOB
 453  * @param out The reply, as an talloc()ed DATA_BLOB, on *out_mem_ctx
 454  * @return Error, MORE_PROCESSING_REQUIRED if a reply is sent,
 455  *                or NT_STATUS_OK if the user is authenticated.
 456  */
 457
 458 static NTSTATUS gensec_krb5_update(struct gensec_security *gensec_security,
 459                                    TALLOC_CTX *out_mem_ctx,
 460                                    const DATA_BLOB in, DATA_BLOB *out)
 461 {
 462         struct gensec_krb5_state *gensec_krb5_state = gensec_security->private_data;
 463         krb5_error_code ret = 0;
 464         DATA_BLOB pac;
 465         NTSTATUS nt_status;
 466
 467         switch (gensec_krb5_state->state_position) {
 468         case GENSEC_KRB5_CLIENT_START:
 469         {
 470                 if (ret) {
 471                         DEBUG(1,("ads_krb5_mk_req (request ticket) failed (%s)\n",
 472                                  error_message(ret)));
 473                         nt_status = NT_STATUS_LOGON_FAILURE;
 474                 } else {
 475                         DATA_BLOB unwrapped_out;
 476
 477 #ifndef GENSEC_SEND_UNWRAPPED_KRB5 /* This should be a switch for the torture code to set */
 478                         unwrapped_out = data_blob_talloc(out_mem_ctx, gensec_krb5_state->ticket.data, gensec_krb5_state->ticket.length);
 479
 480                         /* wrap that up in a nice GSS-API wrapping */
 481                         *out = gensec_gssapi_gen_krb5_wrap(out_mem_ctx, &unwrapped_out, TOK_ID_KRB_AP_REQ);
 482 #else
 483                         *out = data_blob_talloc(out_mem_ctx, gensec_krb5_state->ticket.data, gensec_krb5_state->ticket.length);
 484 #endif
 485                         gensec_krb5_state->state_position = GENSEC_KRB5_CLIENT_MUTUAL_AUTH;
 486                         nt_status = NT_STATUS_MORE_PROCESSING_REQUIRED;
 487                 }
 488
 489                 return nt_status;
 490         }
 491
 492         case GENSEC_KRB5_CLIENT_MUTUAL_AUTH:
 493         {
 494                 krb5_data inbuf;
 495                 krb5_ap_rep_enc_part *repl = NULL;
 496                 uint8_t tok_id[2];
 497                 DATA_BLOB unwrapped_in;
 498
 499                 if (!gensec_gssapi_parse_krb5_wrap(out_mem_ctx, &in, &unwrapped_in, tok_id)) {
 500                         DEBUG(1,("gensec_gssapi_parse_krb5_wrap(mutual authentication) failed to parse\n"));
 501                         dump_data_pw("Mutual authentication message:\n", in.data, in.length);
 502                         return NT_STATUS_INVALID_PARAMETER;
 503                 }
 504                 /* TODO: check the tok_id */
 505
 506                 inbuf.data = unwrapped_in.data;
 507                 inbuf.length = unwrapped_in.length;
 508                 ret = krb5_rd_rep(gensec_krb5_state->context,
 509                                   gensec_krb5_state->auth_context,
 510                                   &inbuf, &repl);
 511                 if (ret) {
 512                         DEBUG(1,("krb5_rd_rep (mutual authentication) failed (%s)\n",
 513                                  error_message(ret)));
 514                         dump_data_pw("Mutual authentication message:\n", inbuf.data, inbuf.length);
 515                         nt_status = NT_STATUS_ACCESS_DENIED;
 516                 } else {
 517                         *out = data_blob(NULL, 0);
 518                         nt_status = NT_STATUS_OK;
 519                         gensec_krb5_state->state_position = GENSEC_KRB5_DONE;
 520                 }
 521                 if (repl) {
 522                         krb5_free_ap_rep_enc_part(gensec_krb5_state->context, repl);
 523                 }
 524                 return nt_status;
 525         }
 526
 527         case GENSEC_KRB5_SERVER_START:
 528         {
 529                 char *principal;
 530                 DATA_BLOB unwrapped_in;
 531                 DATA_BLOB unwrapped_out = data_blob(NULL, 0);
 532                 uint8_t tok_id[2];
 533
 534                 if (!in.data) {
 535                         *out = unwrapped_out;
 536                         return NT_STATUS_MORE_PROCESSING_REQUIRED;
 537                 }
 538
 539                 /* Parse the GSSAPI wrapping, if it's there... (win2k3 allows it to be omited) */
 540                 if (!gensec_gssapi_parse_krb5_wrap(out_mem_ctx, &in, &unwrapped_in, tok_id)) {
 541                         nt_status = ads_verify_ticket(out_mem_ctx,
 542                                                       gensec_krb5_state->context,
 543                                                       gensec_krb5_state->auth_context,
 544                                                       lp_realm(),
 545                                                       gensec_get_target_service(gensec_security), &in,
 546                                                       &principal, &pac, &unwrapped_out,
 547                                                       &gensec_krb5_state->keyblock);
 548                 } else {
 549                         /* TODO: check the tok_id */
 550                         nt_status = ads_verify_ticket(out_mem_ctx,
 551                                                       gensec_krb5_state->context,
 552                                                       gensec_krb5_state->auth_context,
 553                                                       lp_realm(),
 554                                                       gensec_get_target_service(gensec_security),
 555                                                       &unwrapped_in,
 556                                                       &principal, &pac, &unwrapped_out,
 557                                                       &gensec_krb5_state->keyblock);
 558                 }
 559
 560                 if (!NT_STATUS_IS_OK(nt_status)) {
 561                         return nt_status;
 562                 }
 563
 564                 if (pac.data) {
 565                         gensec_krb5_state->pac = data_blob_talloc_reference(gensec_krb5_state, &pac);
 566                 }
 567
 568                 if (NT_STATUS_IS_OK(nt_status)) {
 569                         gensec_krb5_state->state_position = GENSEC_KRB5_DONE;
 570                         /* wrap that up in a nice GSS-API wrapping */
 571 #ifndef GENSEC_SEND_UNWRAPPED_KRB5
 572                         *out = gensec_gssapi_gen_krb5_wrap(out_mem_ctx, &unwrapped_out, TOK_ID_KRB_AP_REP);
 573 #else
 574                         *out = unwrapped_out;
 575 #endif
 576                         gensec_krb5_state->peer_principal = talloc_steal(gensec_krb5_state, principal);
 577                 }
 578                 return nt_status;
 579         }
 580         case GENSEC_KRB5_DONE:
 581                 return NT_STATUS_OK;
 582         }
 583
 584         return NT_STATUS_INVALID_PARAMETER;
 585 }
 586
 587 static NTSTATUS gensec_krb5_session_key(struct gensec_security *gensec_security,
 588                                            DATA_BLOB *session_key)
 589 {
 590         struct gensec_krb5_state *gensec_krb5_state = gensec_security->private_data;
 591         krb5_context context = gensec_krb5_state->context;
 592         krb5_auth_context auth_context = gensec_krb5_state->auth_context;
 593         krb5_keyblock *skey;
 594         krb5_error_code err;
 595
 596         if (gensec_krb5_state->session_key.data) {
 597                 *session_key = gensec_krb5_state->session_key;
 598                 return NT_STATUS_OK;
 599         }
 600
 601         switch (gensec_security->gensec_role) {
 602         case GENSEC_CLIENT:
 603                 err = krb5_auth_con_getlocalsubkey(context, auth_context, &skey);
 604                 break;
 605         case GENSEC_SERVER:
 606                 err = krb5_auth_con_getremotesubkey(context, auth_context, &skey);
 607                 break;
 608         }
 609         if (err == 0 && skey != NULL) {
 610                 DEBUG(10, ("Got KRB5 session key of length %d\n",  KRB5_KEY_LENGTH(skey)));
 611                 gensec_krb5_state->session_key = data_blob_talloc(gensec_krb5_state,
 612                                                 KRB5_KEY_DATA(skey), KRB5_KEY_LENGTH(skey));
 613                 *session_key = gensec_krb5_state->session_key;
 614                 dump_data_pw("KRB5 Session Key:\n", session_key->data, session_key->length);
 615
 616                 krb5_free_keyblock(context, skey);
 617                 return NT_STATUS_OK;
 618         } else {
 619                 DEBUG(10, ("KRB5 error getting session key %d\n", err));
 620                 return NT_STATUS_NO_USER_SESSION_KEY;
 621         }
 622 }
 623
 624 static NTSTATUS gensec_krb5_session_info(struct gensec_security *gensec_security,
 625                                          struct auth_session_info **_session_info)
 626 {
 627         NTSTATUS nt_status;
 628         struct gensec_krb5_state *gensec_krb5_state = gensec_security->private_data;
 629         struct auth_serversupplied_info *server_info = NULL;
 630         struct auth_session_info *session_info = NULL;
 631         struct PAC_LOGON_INFO *logon_info;
 632         char *p;
 633         char *principal;
 634         const char *account_name;
 635         const char *realm;
 636
 637         principal = talloc_strdup(gensec_krb5_state, gensec_krb5_state->peer_principal);
 638         NT_STATUS_HAVE_NO_MEMORY(principal);
 639
 640         p = strchr(principal, '@');
 641         if (p) {
 642                 *p = '\0';
 643                 p++;
 644                 realm = p;
 645         } else {
 646                 realm = lp_realm();
 647         }
 648         account_name = principal;
 649
 650         /* decode and verify the pac */
 651         nt_status = gensec_krb5_decode_pac(gensec_krb5_state, &logon_info, gensec_krb5_state->pac,
 652                                            gensec_krb5_state);
 653
 654         /* IF we have the PAC - otherwise we need to get this
 655          * data from elsewere - local ldb, or (TODO) lookup of some
 656          * kind...
 657          *
 658          * when heimdal can generate the PAC, we should fail if there's
 659          * no PAC present
 660          */
 661
 662         if (NT_STATUS_IS_OK(nt_status)) {
 663                 union netr_Validation validation;
 664                 validation.sam3 = &logon_info->info3;
 665                 nt_status = make_server_info_netlogon_validation(gensec_krb5_state,
 666                                                                  account_name,
 667                                                                  3, &validation,
 668                                                                  &server_info);
 669                 talloc_free(principal);
 670                 NT_STATUS_NOT_OK_RETURN(nt_status);
 671         } else {
 672                 DATA_BLOB user_sess_key = data_blob(NULL, 0);
 673                 DATA_BLOB lm_sess_key = data_blob(NULL, 0);
 674                 /* TODO: should we pass the krb5 session key in here? */
 675                 nt_status = sam_get_server_info(gensec_krb5_state, account_name, realm,
 676                                                 user_sess_key, lm_sess_key,
 677                                                 &server_info);
 678                 talloc_free(principal);
 679                 NT_STATUS_NOT_OK_RETURN(nt_status);
 680         }
 681
 682         /* references the server_info into the session_info */
 683         nt_status = auth_generate_session_info(gensec_krb5_state, server_info, &session_info);
 684         talloc_free(server_info);
 685         NT_STATUS_NOT_OK_RETURN(nt_status);
 686
 687         nt_status = gensec_krb5_session_key(gensec_security, &session_info->session_key);
 688         NT_STATUS_NOT_OK_RETURN(nt_status);
 689
 690         *_session_info = session_info;
 691
 692         return NT_STATUS_OK;
 693 }
 694
 695 static BOOL gensec_krb5_have_feature(struct gensec_security *gensec_security,
 696                                      uint32_t feature)
 697 {
 698         if (feature & GENSEC_FEATURE_SESSION_KEY) {
 699                 return True;
 700         }
 701
 702         return False;
 703 }
 704
 705
 706 static const struct gensec_security_ops gensec_krb5_security_ops = {
 707         .name           = "krb5",
 708         .auth_type      = DCERPC_AUTH_TYPE_KRB5,
 709         .oid            = GENSEC_OID_KERBEROS5,
 710         .client_start   = gensec_krb5_client_start,
 711         .server_start   = gensec_krb5_server_start,
 712         .update         = gensec_krb5_update,
 713         .session_key    = gensec_krb5_session_key,
 714         .session_info   = gensec_krb5_session_info,
 715         .have_feature   = gensec_krb5_have_feature,
 716         .enabled        = False
 717 };
 718
 719 static const struct gensec_security_ops gensec_ms_krb5_security_ops = {
 720         .name           = "ms_krb5",
 721         .auth_type      = DCERPC_AUTH_TYPE_KRB5,
 722         .oid            = GENSEC_OID_KERBEROS5_OLD,
 723         .client_start   = gensec_krb5_client_start,
 724         .server_start   = gensec_krb5_server_start,
 725         .update         = gensec_krb5_update,
 726         .session_key    = gensec_krb5_session_key,
 727         .session_info   = gensec_krb5_session_info,
 728         .have_feature   = gensec_krb5_have_feature,
 729         .enabled        = False
 730 };
 731
 732
 733 NTSTATUS gensec_krb5_init(void)
 734 {
 735         NTSTATUS ret;
 736
 737         ret = gensec_register(&gensec_krb5_security_ops);
 738         if (!NT_STATUS_IS_OK(ret)) {
 739                 DEBUG(0,("Failed to register '%s' gensec backend!\n",
 740                         gensec_krb5_security_ops.name));
 741                 return ret;
 742         }
 743
 744         ret = gensec_register(&gensec_ms_krb5_security_ops);
 745         if (!NT_STATUS_IS_OK(ret)) {
 746                 DEBUG(0,("Failed to register '%s' gensec backend!\n",
 747                         gensec_krb5_security_ops.name));
 748                 return ret;
 749         }
 750
 751         return ret;
 752 }