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",
 226                  logon_info->info3.base.account_name.string,
 227                  logon_info->info3.base.full_name.string));
 228         *logon_info_out = logon_info;
 229
 230         return status;
 231 }
 232
 233 static int gensec_krb5_destory(void *ptr)
 234 {
 235         struct gensec_krb5_state *gensec_krb5_state = ptr;
 236
 237         if (gensec_krb5_state->ticket.length) {
 238                 kerberos_free_data_contents(gensec_krb5_state->context,
 239                                             &gensec_krb5_state->ticket);
 240         }
 241         /* ccache freed in a child destructor */
 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",
 283                          smb_get_krb5_error_message(gensec_krb5_state->context,
 284                                                     ret, gensec_krb5_state)));
 285                 return NT_STATUS_INTERNAL_ERROR;
 286         }
 287
 288         if (lp_realm() && *lp_realm()) {
 289                 char *upper_realm = strupper_talloc(gensec_krb5_state, lp_realm());
 290                 if (!upper_realm) {
 291                         DEBUG(1,("gensec_krb5_start: could not uppercase realm: %s\n", lp_realm()));
 292                         return NT_STATUS_NO_MEMORY;
 293                 }
 294                 ret = krb5_set_default_realm(gensec_krb5_state->context, upper_realm);
 295                 if (ret) {
 296                         DEBUG(1,("gensec_krb5_start: krb5_set_default_realm failed (%s)\n",
 297                                  smb_get_krb5_error_message(gensec_krb5_state->context,
 298                                                             ret, gensec_krb5_state)));
 299                         return NT_STATUS_INTERNAL_ERROR;
 300                 }
 301         }
 302
 303         ret = krb5_auth_con_init(gensec_krb5_state->context, &gensec_krb5_state->auth_context);
 304         if (ret) {
 305                 DEBUG(1,("gensec_krb5_start: krb5_auth_con_init failed (%s)\n",
 306                          smb_get_krb5_error_message(gensec_krb5_state->context,
 307                                                     ret, gensec_krb5_state)));
 308                 return NT_STATUS_INTERNAL_ERROR;
 309         }
 310
 311         return NT_STATUS_OK;
 312 }
 313
 314 static NTSTATUS gensec_krb5_server_start(struct gensec_security *gensec_security)
 315 {
 316         NTSTATUS nt_status;
 317         struct gensec_krb5_state *gensec_krb5_state;
 318
 319         nt_status = gensec_krb5_start(gensec_security);
 320         if (!NT_STATUS_IS_OK(nt_status)) {
 321                 return nt_status;
 322         }
 323
 324         gensec_krb5_state = gensec_security->private_data;
 325         gensec_krb5_state->state_position = GENSEC_KRB5_SERVER_START;
 326
 327         return NT_STATUS_OK;
 328 }
 329
 330 static NTSTATUS gensec_krb5_client_start(struct gensec_security *gensec_security)
 331 {
 332         struct gensec_krb5_state *gensec_krb5_state;
 333         krb5_error_code ret;
 334         NTSTATUS nt_status;
 335         const char *ccache_name;
 336
 337         const char *hostname = gensec_get_target_hostname(gensec_security);
 338         if (!hostname) {
 339                 DEBUG(1, ("Could not determine hostname for target computer, cannot use kerberos\n"));
 340                 return NT_STATUS_ACCESS_DENIED;
 341         }
 342
 343         nt_status = gensec_krb5_start(gensec_security);
 344         if (!NT_STATUS_IS_OK(nt_status)) {
 345                 return nt_status;
 346         }
 347
 348         gensec_krb5_state = gensec_security->private_data;
 349         gensec_krb5_state->state_position = GENSEC_KRB5_CLIENT_START;
 350
 351         /* TODO: This is effecivly a static/global variable...
 352
 353            TODO: If the user set a username, we should use an in-memory CCACHE (see below)
 354         */
 355         ret = krb5_cc_default(gensec_krb5_state->context, &gensec_krb5_state->ccache);
 356         if (ret) {
 357                 DEBUG(1,("krb5_cc_default failed (%s)\n",
 358                          smb_get_krb5_error_message(gensec_krb5_state->context, ret, gensec_krb5_state)));
 359                 return NT_STATUS_INTERNAL_ERROR;
 360         }
 361
 362         while (1) {
 363                 {
 364                         krb5_data in_data;
 365                         in_data.length = 0;
 366
 367                         ret = krb5_mk_req(gensec_krb5_state->context,
 368                                           &gensec_krb5_state->auth_context,
 369                                           AP_OPTS_USE_SUBKEY | AP_OPTS_MUTUAL_REQUIRED,
 370                                           gensec_get_target_service(gensec_security),
 371                                           hostname,
 372                                           &in_data, gensec_krb5_state->ccache,
 373                                           &gensec_krb5_state->ticket);
 374
 375                 }
 376                 switch (ret) {
 377                 case 0:
 378                         return NT_STATUS_OK;
 379                 case KRB5KDC_ERR_S_PRINCIPAL_UNKNOWN:
 380                         DEBUG(3, ("Server [%s] is not registered with our KDC: %s\n",
 381                                   hostname, smb_get_krb5_error_message(gensec_krb5_state->context, ret, gensec_krb5_state)));
 382                         return NT_STATUS_ACCESS_DENIED;
 383                 case KRB5KDC_ERR_PREAUTH_FAILED:
 384                 case KRB5KRB_AP_ERR_TKT_EXPIRED:
 385                 case KRB5_CC_END:
 386                         /* Too much clock skew - we will need to kinit to re-skew the clock */
 387                 case KRB5KRB_AP_ERR_SKEW:
 388                 case KRB5_KDCREP_SKEW:
 389                 {
 390                         DEBUG(3, ("kerberos (mk_req) failed: %s\n",
 391                                   smb_get_krb5_error_message(gensec_krb5_state->context, ret, gensec_krb5_state)));
 392                         /* fall down to remaining code */
 393                 }
 394
 395
 396                 /* just don't print a message for these really ordinary messages */
 397                 case KRB5_FCC_NOFILE:
 398                 case KRB5_CC_NOTFOUND:
 399                 case ENOENT:
 400
 401                 nt_status = kinit_to_ccache(gensec_krb5_state,
 402                                             gensec_security->credentials,
 403                                             gensec_krb5_state->context,
 404                                             &gensec_krb5_state->ccache,
 405                                             &ccache_name);
 406
 407                 if (!NT_STATUS_IS_OK(nt_status)) {
 408                         return nt_status;
 409                 }
 410                 break;
 411
 412                 default:
 413                         DEBUG(0, ("kerberos: %s\n",
 414                                   smb_get_krb5_error_message(gensec_krb5_state->context, ret, gensec_krb5_state)));
 415                         return NT_STATUS_UNSUCCESSFUL;
 416                 }
 417         }
 418 }
 419
 420
 421 /**
 422  * Next state function for the Krb5 GENSEC mechanism
 423  *
 424  * @param gensec_krb5_state KRB5 State
 425  * @param out_mem_ctx The TALLOC_CTX for *out to be allocated on
 426  * @param in The request, as a DATA_BLOB
 427  * @param out The reply, as an talloc()ed DATA_BLOB, on *out_mem_ctx
 428  * @return Error, MORE_PROCESSING_REQUIRED if a reply is sent,
 429  *                or NT_STATUS_OK if the user is authenticated.
 430  */
 431
 432 static NTSTATUS gensec_krb5_update(struct gensec_security *gensec_security,
 433                                    TALLOC_CTX *out_mem_ctx,
 434                                    const DATA_BLOB in, DATA_BLOB *out)
 435 {
 436         struct gensec_krb5_state *gensec_krb5_state = gensec_security->private_data;
 437         krb5_error_code ret = 0;
 438         DATA_BLOB pac;
 439         NTSTATUS nt_status;
 440
 441         switch (gensec_krb5_state->state_position) {
 442         case GENSEC_KRB5_CLIENT_START:
 443         {
 444                 if (ret) {
 445                         DEBUG(1,("ads_krb5_mk_req (request ticket) failed (%s)\n",
 446                                  smb_get_krb5_error_message(gensec_krb5_state->context, ret, out_mem_ctx)));
 447                         nt_status = NT_STATUS_LOGON_FAILURE;
 448                 } else {
 449                         DATA_BLOB unwrapped_out;
 450
 451 #ifndef GENSEC_SEND_UNWRAPPED_KRB5 /* This should be a switch for the torture code to set */
 452                         unwrapped_out = data_blob_talloc(out_mem_ctx, gensec_krb5_state->ticket.data, gensec_krb5_state->ticket.length);
 453
 454                         /* wrap that up in a nice GSS-API wrapping */
 455                         *out = gensec_gssapi_gen_krb5_wrap(out_mem_ctx, &unwrapped_out, TOK_ID_KRB_AP_REQ);
 456 #else
 457                         *out = data_blob_talloc(out_mem_ctx, gensec_krb5_state->ticket.data, gensec_krb5_state->ticket.length);
 458 #endif
 459                         gensec_krb5_state->state_position = GENSEC_KRB5_CLIENT_MUTUAL_AUTH;
 460                         nt_status = NT_STATUS_MORE_PROCESSING_REQUIRED;
 461                 }
 462
 463                 return nt_status;
 464         }
 465
 466         case GENSEC_KRB5_CLIENT_MUTUAL_AUTH:
 467         {
 468                 krb5_data inbuf;
 469                 krb5_ap_rep_enc_part *repl = NULL;
 470                 uint8_t tok_id[2];
 471                 DATA_BLOB unwrapped_in;
 472
 473                 if (!gensec_gssapi_parse_krb5_wrap(out_mem_ctx, &in, &unwrapped_in, tok_id)) {
 474                         DEBUG(1,("gensec_gssapi_parse_krb5_wrap(mutual authentication) failed to parse\n"));
 475                         dump_data_pw("Mutual authentication message:\n", in.data, in.length);
 476                         return NT_STATUS_INVALID_PARAMETER;
 477                 }
 478                 /* TODO: check the tok_id */
 479
 480                 inbuf.data = unwrapped_in.data;
 481                 inbuf.length = unwrapped_in.length;
 482                 ret = krb5_rd_rep(gensec_krb5_state->context,
 483                                   gensec_krb5_state->auth_context,
 484                                   &inbuf, &repl);
 485                 if (ret) {
 486                         DEBUG(1,("krb5_rd_rep (mutual authentication) failed (%s)\n",
 487                                  smb_get_krb5_error_message(gensec_krb5_state->context, ret, out_mem_ctx)));
 488                         dump_data_pw("Mutual authentication message:\n", inbuf.data, inbuf.length);
 489                         nt_status = NT_STATUS_ACCESS_DENIED;
 490                 } else {
 491                         *out = data_blob(NULL, 0);
 492                         nt_status = NT_STATUS_OK;
 493                         gensec_krb5_state->state_position = GENSEC_KRB5_DONE;
 494                 }
 495                 if (repl) {
 496                         krb5_free_ap_rep_enc_part(gensec_krb5_state->context, repl);
 497                 }
 498                 return nt_status;
 499         }
 500
 501         case GENSEC_KRB5_SERVER_START:
 502         {
 503                 char *principal;
 504                 DATA_BLOB unwrapped_in;
 505                 DATA_BLOB unwrapped_out = data_blob(NULL, 0);
 506                 uint8_t tok_id[2];
 507
 508                 if (!in.data) {
 509                         *out = unwrapped_out;
 510                         return NT_STATUS_MORE_PROCESSING_REQUIRED;
 511                 }
 512
 513                 /* Parse the GSSAPI wrapping, if it's there... (win2k3 allows it to be omited) */
 514                 if (!gensec_gssapi_parse_krb5_wrap(out_mem_ctx, &in, &unwrapped_in, tok_id)) {
 515                         nt_status = ads_verify_ticket(out_mem_ctx,
 516                                                       gensec_krb5_state->context,
 517                                                       gensec_krb5_state->auth_context,
 518                                                       lp_realm(),
 519                                                       gensec_get_target_service(gensec_security), &in,
 520                                                       &principal, &pac, &unwrapped_out,
 521                                                       &gensec_krb5_state->keyblock);
 522                 } else {
 523                         /* TODO: check the tok_id */
 524                         nt_status = ads_verify_ticket(out_mem_ctx,
 525                                                       gensec_krb5_state->context,
 526                                                       gensec_krb5_state->auth_context,
 527                                                       lp_realm(),
 528                                                       gensec_get_target_service(gensec_security),
 529                                                       &unwrapped_in,
 530                                                       &principal, &pac, &unwrapped_out,
 531                                                       &gensec_krb5_state->keyblock);
 532                 }
 533
 534                 if (!NT_STATUS_IS_OK(nt_status)) {
 535                         return nt_status;
 536                 }
 537
 538                 if (pac.data) {
 539                         gensec_krb5_state->pac = data_blob_talloc_reference(gensec_krb5_state, &pac);
 540                 }
 541
 542                 if (NT_STATUS_IS_OK(nt_status)) {
 543                         gensec_krb5_state->state_position = GENSEC_KRB5_DONE;
 544                         /* wrap that up in a nice GSS-API wrapping */
 545 #ifndef GENSEC_SEND_UNWRAPPED_KRB5
 546                         *out = gensec_gssapi_gen_krb5_wrap(out_mem_ctx, &unwrapped_out, TOK_ID_KRB_AP_REP);
 547 #else
 548                         *out = unwrapped_out;
 549 #endif
 550                         gensec_krb5_state->peer_principal = talloc_steal(gensec_krb5_state, principal);
 551                 }
 552                 return nt_status;
 553         }
 554         case GENSEC_KRB5_DONE:
 555                 return NT_STATUS_OK;
 556         }
 557
 558         return NT_STATUS_INVALID_PARAMETER;
 559 }
 560
 561 static NTSTATUS gensec_krb5_session_key(struct gensec_security *gensec_security,
 562                                            DATA_BLOB *session_key)
 563 {
 564         struct gensec_krb5_state *gensec_krb5_state = gensec_security->private_data;
 565         krb5_context context = gensec_krb5_state->context;
 566         krb5_auth_context auth_context = gensec_krb5_state->auth_context;
 567         krb5_keyblock *skey;
 568         krb5_error_code err;
 569
 570         if (gensec_krb5_state->session_key.data) {
 571                 *session_key = gensec_krb5_state->session_key;
 572                 return NT_STATUS_OK;
 573         }
 574
 575         switch (gensec_security->gensec_role) {
 576         case GENSEC_CLIENT:
 577                 err = krb5_auth_con_getlocalsubkey(context, auth_context, &skey);
 578                 break;
 579         case GENSEC_SERVER:
 580                 err = krb5_auth_con_getremotesubkey(context, auth_context, &skey);
 581                 break;
 582         }
 583         if (err == 0 && skey != NULL) {
 584                 DEBUG(10, ("Got KRB5 session key of length %d\n",  KRB5_KEY_LENGTH(skey)));
 585                 gensec_krb5_state->session_key = data_blob_talloc(gensec_krb5_state,
 586                                                 KRB5_KEY_DATA(skey), KRB5_KEY_LENGTH(skey));
 587                 *session_key = gensec_krb5_state->session_key;
 588                 dump_data_pw("KRB5 Session Key:\n", session_key->data, session_key->length);
 589
 590                 krb5_free_keyblock(context, skey);
 591                 return NT_STATUS_OK;
 592         } else {
 593                 DEBUG(10, ("KRB5 error getting session key %d\n", err));
 594                 return NT_STATUS_NO_USER_SESSION_KEY;
 595         }
 596 }
 597
 598 static NTSTATUS gensec_krb5_session_info(struct gensec_security *gensec_security,
 599                                          struct auth_session_info **_session_info)
 600 {
 601         NTSTATUS nt_status;
 602         struct gensec_krb5_state *gensec_krb5_state = gensec_security->private_data;
 603         struct auth_serversupplied_info *server_info = NULL;
 604         struct auth_session_info *session_info = NULL;
 605         struct PAC_LOGON_INFO *logon_info;
 606         char *p;
 607         char *principal;
 608         const char *account_name;
 609         const char *realm;
 610
 611         principal = talloc_strdup(gensec_krb5_state, gensec_krb5_state->peer_principal);
 612         NT_STATUS_HAVE_NO_MEMORY(principal);
 613
 614         p = strchr(principal, '@');
 615         if (p) {
 616                 *p = '\0';
 617                 p++;
 618                 realm = p;
 619         } else {
 620                 realm = lp_realm();
 621         }
 622         account_name = principal;
 623
 624         /* decode and verify the pac */
 625         nt_status = gensec_krb5_decode_pac(gensec_krb5_state, &logon_info, gensec_krb5_state->pac,
 626                                            gensec_krb5_state);
 627
 628         /* IF we have the PAC - otherwise we need to get this
 629          * data from elsewere - local ldb, or (TODO) lookup of some
 630          * kind...
 631          *
 632          * when heimdal can generate the PAC, we should fail if there's
 633          * no PAC present
 634          */
 635
 636         if (NT_STATUS_IS_OK(nt_status)) {
 637                 union netr_Validation validation;
 638                 validation.sam3 = &logon_info->info3;
 639                 nt_status = make_server_info_netlogon_validation(gensec_krb5_state,
 640                                                                  account_name,
 641                                                                  3, &validation,
 642                                                                  &server_info);
 643                 talloc_free(principal);
 644                 NT_STATUS_NOT_OK_RETURN(nt_status);
 645         } else {
 646                 DATA_BLOB user_sess_key = data_blob(NULL, 0);
 647                 DATA_BLOB lm_sess_key = data_blob(NULL, 0);
 648                 /* TODO: should we pass the krb5 session key in here? */
 649                 nt_status = sam_get_server_info(gensec_krb5_state, account_name, realm,
 650                                                 user_sess_key, lm_sess_key,
 651                                                 &server_info);
 652                 talloc_free(principal);
 653                 NT_STATUS_NOT_OK_RETURN(nt_status);
 654         }
 655
 656         /* references the server_info into the session_info */
 657         nt_status = auth_generate_session_info(gensec_krb5_state, server_info, &session_info);
 658         talloc_free(server_info);
 659         NT_STATUS_NOT_OK_RETURN(nt_status);
 660
 661         nt_status = gensec_krb5_session_key(gensec_security, &session_info->session_key);
 662         NT_STATUS_NOT_OK_RETURN(nt_status);
 663
 664         *_session_info = session_info;
 665
 666         return NT_STATUS_OK;
 667 }
 668
 669 static BOOL gensec_krb5_have_feature(struct gensec_security *gensec_security,
 670                                      uint32_t feature)
 671 {
 672         if (feature & GENSEC_FEATURE_SESSION_KEY) {
 673                 return True;
 674         }
 675
 676         return False;
 677 }
 678
 679 static const char *gensec_krb5_oids[] = {
 680         GENSEC_OID_KERBEROS5,
 681         GENSEC_OID_KERBEROS5_OLD,
 682         NULL
 683 };
 684
 685 static const struct gensec_security_ops gensec_krb5_security_ops = {
 686         .name           = "krb5",
 687         .auth_type      = DCERPC_AUTH_TYPE_KRB5,
 688         .oid            = gensec_krb5_oids,
 689         .client_start   = gensec_krb5_client_start,
 690         .server_start   = gensec_krb5_server_start,
 691         .update         = gensec_krb5_update,
 692         .session_key    = gensec_krb5_session_key,
 693         .session_info   = gensec_krb5_session_info,
 694         .have_feature   = gensec_krb5_have_feature,
 695         .enabled        = False
 696 };
 697
 698 NTSTATUS gensec_krb5_init(void)
 699 {
 700         NTSTATUS ret;
 701
 702         ret = gensec_register(&gensec_krb5_security_ops);
 703         if (!NT_STATUS_IS_OK(ret)) {
 704                 DEBUG(0,("Failed to register '%s' gensec backend!\n",
 705                         gensec_krb5_security_ops.name));
 706                 return ret;
 707         }
 708
 709         return ret;
 710 }