source/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 "auth/kerberos/kerberos.h"
  30 #include "librpc/gen_ndr/krb5pac.h"
  31 #include "auth/auth.h"
  32 #include "lib/ldb/include/ldb.h"
  33 #include "auth/auth_sam.h"
  34 #include "system/network.h"
  35 #include "lib/socket/socket.h"
  36 #include "librpc/rpc/dcerpc.h"
  37 #include "auth/credentials/credentials.h"
  38 #include "auth/credentials/credentials_krb5.h"
  39 #include "auth/gensec/gensec.h"
  40
  41 enum GENSEC_KRB5_STATE {
  42         GENSEC_KRB5_SERVER_START,
  43         GENSEC_KRB5_CLIENT_START,
  44         GENSEC_KRB5_CLIENT_MUTUAL_AUTH,
  45         GENSEC_KRB5_DONE
  46 };
  47
  48 struct gensec_krb5_state {
  49         DATA_BLOB session_key;
  50         DATA_BLOB pac;
  51         enum GENSEC_KRB5_STATE state_position;
  52         struct smb_krb5_context *smb_krb5_context;
  53         krb5_auth_context auth_context;
  54         krb5_data enc_ticket;
  55         krb5_keyblock *keyblock;
  56         krb5_ticket *ticket;
  57         BOOL gssapi;
  58 };
  59
  60 static int gensec_krb5_destroy(struct gensec_krb5_state *gensec_krb5_state)
  61 {
  62         if (!gensec_krb5_state->smb_krb5_context) {
  63                 /* We can't clean anything else up unless we started up this far */
  64                 return 0;
  65         }
  66         if (gensec_krb5_state->enc_ticket.length) {
  67                 kerberos_free_data_contents(gensec_krb5_state->smb_krb5_context->krb5_context,
  68                                             &gensec_krb5_state->enc_ticket);
  69         }
  70
  71         if (gensec_krb5_state->ticket) {
  72                 krb5_free_ticket(gensec_krb5_state->smb_krb5_context->krb5_context,
  73                                  gensec_krb5_state->ticket);
  74         }
  75
  76         /* ccache freed in a child destructor */
  77
  78         krb5_free_keyblock(gensec_krb5_state->smb_krb5_context->krb5_context,
  79                            gensec_krb5_state->keyblock);
  80
  81         if (gensec_krb5_state->auth_context) {
  82                 krb5_auth_con_free(gensec_krb5_state->smb_krb5_context->krb5_context,
  83                                    gensec_krb5_state->auth_context);
  84         }
  85
  86         return 0;
  87 }
  88
  89 static NTSTATUS gensec_krb5_start(struct gensec_security *gensec_security)
  90 {
  91         krb5_error_code ret;
  92         struct gensec_krb5_state *gensec_krb5_state;
  93         struct cli_credentials *creds;
  94         const struct socket_address *my_addr, *peer_addr;
  95         krb5_address my_krb5_addr, peer_krb5_addr;
  96
  97         creds = gensec_get_credentials(gensec_security);
  98         if (!creds) {
  99                 return NT_STATUS_INVALID_PARAMETER;
 100         }
 101
 102         gensec_krb5_state = talloc(gensec_security, struct gensec_krb5_state);
 103         if (!gensec_krb5_state) {
 104                 return NT_STATUS_NO_MEMORY;
 105         }
 106
 107         gensec_security->private_data = gensec_krb5_state;
 108         gensec_krb5_state->smb_krb5_context = NULL;
 109         gensec_krb5_state->auth_context = NULL;
 110         gensec_krb5_state->ticket = NULL;
 111         ZERO_STRUCT(gensec_krb5_state->enc_ticket);
 112         gensec_krb5_state->keyblock = NULL;
 113         gensec_krb5_state->session_key = data_blob(NULL, 0);
 114         gensec_krb5_state->pac = data_blob(NULL, 0);
 115         gensec_krb5_state->gssapi = False;
 116
 117         talloc_set_destructor(gensec_krb5_state, gensec_krb5_destroy);
 118
 119         if (cli_credentials_get_krb5_context(creds, &gensec_krb5_state->smb_krb5_context)) {
 120                 talloc_free(gensec_krb5_state);
 121                 return NT_STATUS_INTERNAL_ERROR;
 122         }
 123
 124         ret = krb5_auth_con_init(gensec_krb5_state->smb_krb5_context->krb5_context, &gensec_krb5_state->auth_context);
 125         if (ret) {
 126                 DEBUG(1,("gensec_krb5_start: krb5_auth_con_init failed (%s)\n",
 127                          smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context,
 128                                                     ret, gensec_krb5_state)));
 129                 talloc_free(gensec_krb5_state);
 130                 return NT_STATUS_INTERNAL_ERROR;
 131         }
 132
 133         ret = krb5_auth_con_setflags(gensec_krb5_state->smb_krb5_context->krb5_context,
 134                                      gensec_krb5_state->auth_context,
 135                                      KRB5_AUTH_CONTEXT_DO_SEQUENCE);
 136         if (ret) {
 137                 DEBUG(1,("gensec_krb5_start: krb5_auth_con_setflags failed (%s)\n",
 138                          smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context,
 139                                                     ret, gensec_krb5_state)));
 140                 talloc_free(gensec_krb5_state);
 141                 return NT_STATUS_INTERNAL_ERROR;
 142         }
 143
 144         my_addr = gensec_get_my_addr(gensec_security);
 145         if (my_addr && my_addr->sockaddr) {
 146                 ret = krb5_sockaddr2address(gensec_krb5_state->smb_krb5_context->krb5_context,
 147                                             my_addr->sockaddr, &my_krb5_addr);
 148                 if (ret) {
 149                         DEBUG(1,("gensec_krb5_start: krb5_sockaddr2address (local) failed (%s)\n",
 150                                  smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context,
 151                                                             ret, gensec_krb5_state)));
 152                         talloc_free(gensec_krb5_state);
 153                         return NT_STATUS_INTERNAL_ERROR;
 154                 }
 155         }
 156
 157         peer_addr = gensec_get_peer_addr(gensec_security);
 158         if (peer_addr && peer_addr->sockaddr) {
 159                 ret = krb5_sockaddr2address(gensec_krb5_state->smb_krb5_context->krb5_context,
 160                                             peer_addr->sockaddr, &peer_krb5_addr);
 161                 if (ret) {
 162                         DEBUG(1,("gensec_krb5_start: krb5_sockaddr2address (local) failed (%s)\n",
 163                                  smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context,
 164                                                             ret, gensec_krb5_state)));
 165                         talloc_free(gensec_krb5_state);
 166                         return NT_STATUS_INTERNAL_ERROR;
 167                 }
 168         }
 169
 170         ret = krb5_auth_con_setaddrs(gensec_krb5_state->smb_krb5_context->krb5_context,
 171                                      gensec_krb5_state->auth_context,
 172                                      my_addr ? &my_krb5_addr : NULL,
 173                                      peer_addr ? &peer_krb5_addr : NULL);
 174         if (ret) {
 175                 DEBUG(1,("gensec_krb5_start: krb5_auth_con_setaddrs failed (%s)\n",
 176                          smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context,
 177                                                     ret, gensec_krb5_state)));
 178                 talloc_free(gensec_krb5_state);
 179                 return NT_STATUS_INTERNAL_ERROR;
 180         }
 181
 182         return NT_STATUS_OK;
 183 }
 184
 185 static NTSTATUS gensec_krb5_server_start(struct gensec_security *gensec_security)
 186 {
 187         NTSTATUS nt_status;
 188         struct gensec_krb5_state *gensec_krb5_state;
 189
 190         nt_status = gensec_krb5_start(gensec_security);
 191         if (!NT_STATUS_IS_OK(nt_status)) {
 192                 return nt_status;
 193         }
 194
 195         gensec_krb5_state = gensec_security->private_data;
 196         gensec_krb5_state->state_position = GENSEC_KRB5_SERVER_START;
 197
 198         return NT_STATUS_OK;
 199 }
 200
 201 static NTSTATUS gensec_fake_gssapi_krb5_server_start(struct gensec_security *gensec_security)
 202 {
 203         NTSTATUS nt_status = gensec_krb5_server_start(gensec_security);
 204
 205         if (NT_STATUS_IS_OK(nt_status)) {
 206                 struct gensec_krb5_state *gensec_krb5_state;
 207                 gensec_krb5_state = gensec_security->private_data;
 208                 gensec_krb5_state->gssapi = True;
 209         }
 210         return nt_status;
 211 }
 212
 213 static NTSTATUS gensec_krb5_client_start(struct gensec_security *gensec_security)
 214 {
 215         struct gensec_krb5_state *gensec_krb5_state;
 216         krb5_error_code ret;
 217         NTSTATUS nt_status;
 218         struct ccache_container *ccache_container;
 219         const char *hostname;
 220         krb5_flags ap_req_options = AP_OPTS_USE_SUBKEY | AP_OPTS_MUTUAL_REQUIRED;
 221
 222         const char *principal;
 223         krb5_data in_data;
 224
 225         hostname = gensec_get_target_hostname(gensec_security);
 226         if (!hostname) {
 227                 DEBUG(1, ("Could not determine hostname for target computer, cannot use kerberos\n"));
 228                 return NT_STATUS_INVALID_PARAMETER;
 229         }
 230         if (is_ipaddress(hostname)) {
 231                 DEBUG(2, ("Cannot do krb5 to an IP address"));
 232                 return NT_STATUS_INVALID_PARAMETER;
 233         }
 234         if (strcmp(hostname, "localhost") == 0) {
 235                 DEBUG(2, ("krb5 to 'localhost' does not make sense"));
 236                 return NT_STATUS_INVALID_PARAMETER;
 237         }
 238
 239         nt_status = gensec_krb5_start(gensec_security);
 240         if (!NT_STATUS_IS_OK(nt_status)) {
 241                 return nt_status;
 242         }
 243
 244         gensec_krb5_state = gensec_security->private_data;
 245         gensec_krb5_state->state_position = GENSEC_KRB5_CLIENT_START;
 246
 247         ret = cli_credentials_get_ccache(gensec_get_credentials(gensec_security), &ccache_container);
 248         if (ret) {
 249                 DEBUG(1,("gensec_krb5_start: cli_credentials_get_ccache failed: %s\n",
 250                          error_message(ret)));
 251                 return NT_STATUS_UNSUCCESSFUL;
 252         }
 253
 254         in_data.length = 0;
 255
 256         principal = gensec_get_target_principal(gensec_security);
 257         if (principal && lp_client_use_spnego_principal()) {
 258                 krb5_principal target_principal;
 259                 ret = krb5_parse_name(gensec_krb5_state->smb_krb5_context->krb5_context, principal,
 260                                       &target_principal);
 261                 if (ret == 0) {
 262                         ret = krb5_mk_req_exact(gensec_krb5_state->smb_krb5_context->krb5_context,
 263                                                 &gensec_krb5_state->auth_context,
 264                                                 ap_req_options,
 265                                                 target_principal,
 266                                                 &in_data, ccache_container->ccache,
 267                                                 &gensec_krb5_state->enc_ticket);
 268                         krb5_free_principal(gensec_krb5_state->smb_krb5_context->krb5_context,
 269                                             target_principal);
 270                 }
 271         } else {
 272                 ret = krb5_mk_req(gensec_krb5_state->smb_krb5_context->krb5_context,
 273                                   &gensec_krb5_state->auth_context,
 274                                   ap_req_options,
 275                                   gensec_get_target_service(gensec_security),
 276                                   hostname,
 277                                   &in_data, ccache_container->ccache,
 278                                   &gensec_krb5_state->enc_ticket);
 279         }
 280         switch (ret) {
 281         case 0:
 282                 return NT_STATUS_OK;
 283         case KRB5KDC_ERR_S_PRINCIPAL_UNKNOWN:
 284                 DEBUG(3, ("Server [%s] is not registered with our KDC: %s\n",
 285                           hostname, smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context, ret, gensec_krb5_state)));
 286                 return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
 287         case KRB5_KDC_UNREACH:
 288                 DEBUG(3, ("Cannot reach a KDC we require to contact host [%s]: %s\n",
 289                           hostname, smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context, ret, gensec_krb5_state)));
 290                 return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
 291         case KRB5KDC_ERR_PREAUTH_FAILED:
 292         case KRB5KRB_AP_ERR_TKT_EXPIRED:
 293         case KRB5_CC_END:
 294                 /* Too much clock skew - we will need to kinit to re-skew the clock */
 295         case KRB5KRB_AP_ERR_SKEW:
 296         case KRB5_KDCREP_SKEW:
 297         {
 298                 DEBUG(3, ("kerberos (mk_req) failed: %s\n",
 299                           smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context, ret, gensec_krb5_state)));
 300                 /*fall through*/
 301         }
 302
 303         /* just don't print a message for these really ordinary messages */
 304         case KRB5_FCC_NOFILE:
 305         case KRB5_CC_NOTFOUND:
 306         case ENOENT:
 307
 308                 return NT_STATUS_UNSUCCESSFUL;
 309                 break;
 310
 311         default:
 312                 DEBUG(0, ("kerberos: %s\n",
 313                           smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context, ret, gensec_krb5_state)));
 314                 return NT_STATUS_UNSUCCESSFUL;
 315         }
 316 }
 317
 318 static NTSTATUS gensec_fake_gssapi_krb5_client_start(struct gensec_security *gensec_security)
 319 {
 320         NTSTATUS nt_status = gensec_krb5_client_start(gensec_security);
 321
 322         if (NT_STATUS_IS_OK(nt_status)) {
 323                 struct gensec_krb5_state *gensec_krb5_state;
 324                 gensec_krb5_state = gensec_security->private_data;
 325                 gensec_krb5_state->gssapi = True;
 326         }
 327         return nt_status;
 328 }
 329
 330 /**
 331  * Check if the packet is one for this mechansim
 332  *
 333  * @param gensec_security GENSEC state
 334  * @param in The request, as a DATA_BLOB
 335  * @return Error, INVALID_PARAMETER if it's not a packet for us
 336  *                or NT_STATUS_OK if the packet is ok.
 337  */
 338
 339 static NTSTATUS gensec_fake_gssapi_krb5_magic(struct gensec_security *gensec_security,
 340                                   const DATA_BLOB *in)
 341 {
 342         if (gensec_gssapi_check_oid(in, GENSEC_OID_KERBEROS5)) {
 343                 return NT_STATUS_OK;
 344         } else {
 345                 return NT_STATUS_INVALID_PARAMETER;
 346         }
 347 }
 348
 349
 350 /**
 351  * Next state function for the Krb5 GENSEC mechanism
 352  *
 353  * @param gensec_krb5_state KRB5 State
 354  * @param out_mem_ctx The TALLOC_CTX for *out to be allocated on
 355  * @param in The request, as a DATA_BLOB
 356  * @param out The reply, as an talloc()ed DATA_BLOB, on *out_mem_ctx
 357  * @return Error, MORE_PROCESSING_REQUIRED if a reply is sent,
 358  *                or NT_STATUS_OK if the user is authenticated.
 359  */
 360
 361 static NTSTATUS gensec_krb5_update(struct gensec_security *gensec_security,
 362                                    TALLOC_CTX *out_mem_ctx,
 363                                    const DATA_BLOB in, DATA_BLOB *out)
 364 {
 365         struct gensec_krb5_state *gensec_krb5_state = gensec_security->private_data;
 366         krb5_error_code ret = 0;
 367         NTSTATUS nt_status;
 368
 369         switch (gensec_krb5_state->state_position) {
 370         case GENSEC_KRB5_CLIENT_START:
 371         {
 372                 DATA_BLOB unwrapped_out;
 373
 374                 if (gensec_krb5_state->gssapi) {
 375                         unwrapped_out = data_blob_talloc(out_mem_ctx, gensec_krb5_state->enc_ticket.data, gensec_krb5_state->enc_ticket.length);
 376
 377                         /* wrap that up in a nice GSS-API wrapping */
 378                         *out = gensec_gssapi_gen_krb5_wrap(out_mem_ctx, &unwrapped_out, TOK_ID_KRB_AP_REQ);
 379                 } else {
 380                         *out = data_blob_talloc(out_mem_ctx, gensec_krb5_state->enc_ticket.data, gensec_krb5_state->enc_ticket.length);
 381                 }
 382                 gensec_krb5_state->state_position = GENSEC_KRB5_CLIENT_MUTUAL_AUTH;
 383                 nt_status = NT_STATUS_MORE_PROCESSING_REQUIRED;
 384                 return nt_status;
 385         }
 386
 387         case GENSEC_KRB5_CLIENT_MUTUAL_AUTH:
 388         {
 389                 DATA_BLOB unwrapped_in;
 390                 krb5_data inbuf;
 391                 krb5_ap_rep_enc_part *repl = NULL;
 392                 uint8_t tok_id[2];
 393
 394                 if (gensec_krb5_state->gssapi) {
 395                         if (!gensec_gssapi_parse_krb5_wrap(out_mem_ctx, &in, &unwrapped_in, tok_id)) {
 396                                 DEBUG(1,("gensec_gssapi_parse_krb5_wrap(mutual authentication) failed to parse\n"));
 397                                 dump_data_pw("Mutual authentication message:\n", in.data, in.length);
 398                                 return NT_STATUS_INVALID_PARAMETER;
 399                         }
 400                 } else {
 401                         unwrapped_in = in;
 402                 }
 403                 /* TODO: check the tok_id */
 404
 405                 inbuf.data = unwrapped_in.data;
 406                 inbuf.length = unwrapped_in.length;
 407                 ret = krb5_rd_rep(gensec_krb5_state->smb_krb5_context->krb5_context,
 408                                   gensec_krb5_state->auth_context,
 409                                   &inbuf, &repl);
 410                 if (ret) {
 411                         DEBUG(1,("krb5_rd_rep (mutual authentication) failed (%s)\n",
 412                                  smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context, ret, out_mem_ctx)));
 413                         dump_data_pw("Mutual authentication message:\n", inbuf.data, inbuf.length);
 414                         nt_status = NT_STATUS_ACCESS_DENIED;
 415                 } else {
 416                         *out = data_blob(NULL, 0);
 417                         nt_status = NT_STATUS_OK;
 418                         gensec_krb5_state->state_position = GENSEC_KRB5_DONE;
 419                 }
 420                 if (repl) {
 421                         krb5_free_ap_rep_enc_part(gensec_krb5_state->smb_krb5_context->krb5_context, repl);
 422                 }
 423                 return nt_status;
 424         }
 425
 426         case GENSEC_KRB5_SERVER_START:
 427         {
 428                 DATA_BLOB unwrapped_in;
 429                 DATA_BLOB unwrapped_out = data_blob(NULL, 0);
 430                 krb5_data inbuf, outbuf;
 431                 uint8_t tok_id[2];
 432                 struct keytab_container *keytab;
 433                 krb5_principal server_in_keytab;
 434
 435                 if (!in.data) {
 436                         return NT_STATUS_INVALID_PARAMETER;
 437                 }
 438
 439                 /* Grab the keytab, however generated */
 440                 ret = cli_credentials_get_keytab(gensec_get_credentials(gensec_security), &keytab);
 441                 if (ret) {
 442                         return NT_STATUS_CANT_ACCESS_DOMAIN_INFO;
 443                 }
 444
 445                 /* This ensures we lookup the correct entry in that keytab */
 446                 ret = principal_from_credentials(out_mem_ctx, gensec_get_credentials(gensec_security),
 447                                                  gensec_krb5_state->smb_krb5_context,
 448                                                  &server_in_keytab);
 449
 450                 if (ret) {
 451                         return NT_STATUS_CANT_ACCESS_DOMAIN_INFO;
 452                 }
 453
 454                 /* Parse the GSSAPI wrapping, if it's there... (win2k3 allows it to be omited) */
 455                 if (gensec_krb5_state->gssapi
 456                     && gensec_gssapi_parse_krb5_wrap(out_mem_ctx, &in, &unwrapped_in, tok_id)) {
 457                         inbuf.data = unwrapped_in.data;
 458                         inbuf.length = unwrapped_in.length;
 459                 } else {
 460                         inbuf.data = in.data;
 461                         inbuf.length = in.length;
 462                 }
 463
 464                 ret = smb_rd_req_return_stuff(gensec_krb5_state->smb_krb5_context->krb5_context,
 465                                               &gensec_krb5_state->auth_context,
 466                                               &inbuf, keytab->keytab, server_in_keytab,
 467                                               &outbuf,
 468                                               &gensec_krb5_state->ticket,
 469                                               &gensec_krb5_state->keyblock);
 470
 471                 if (ret) {
 472                         return NT_STATUS_LOGON_FAILURE;
 473                 }
 474                 unwrapped_out.data = outbuf.data;
 475                 unwrapped_out.length = outbuf.length;
 476                 gensec_krb5_state->state_position = GENSEC_KRB5_DONE;
 477                 /* wrap that up in a nice GSS-API wrapping */
 478                 if (gensec_krb5_state->gssapi) {
 479                         *out = gensec_gssapi_gen_krb5_wrap(out_mem_ctx, &unwrapped_out, TOK_ID_KRB_AP_REP);
 480                 } else {
 481                         *out = data_blob_talloc(out_mem_ctx, outbuf.data, outbuf.length);
 482                 }
 483                 krb5_data_free(&outbuf);
 484                 return NT_STATUS_OK;
 485         }
 486
 487         case GENSEC_KRB5_DONE:
 488         default:
 489                 /* Asking too many times... */
 490                 return NT_STATUS_INVALID_PARAMETER;
 491         }
 492 }
 493
 494 static NTSTATUS gensec_krb5_session_key(struct gensec_security *gensec_security,
 495                                         DATA_BLOB *session_key)
 496 {
 497         struct gensec_krb5_state *gensec_krb5_state = gensec_security->private_data;
 498         krb5_context context = gensec_krb5_state->smb_krb5_context->krb5_context;
 499         krb5_auth_context auth_context = gensec_krb5_state->auth_context;
 500         krb5_keyblock *skey;
 501         krb5_error_code err = -1;
 502
 503         if (gensec_krb5_state->session_key.data) {
 504                 *session_key = gensec_krb5_state->session_key;
 505                 return NT_STATUS_OK;
 506         }
 507
 508         switch (gensec_security->gensec_role) {
 509         case GENSEC_CLIENT:
 510                 err = krb5_auth_con_getlocalsubkey(context, auth_context, &skey);
 511                 break;
 512         case GENSEC_SERVER:
 513                 err = krb5_auth_con_getremotesubkey(context, auth_context, &skey);
 514                 break;
 515         }
 516         if (err == 0 && skey != NULL) {
 517                 DEBUG(10, ("Got KRB5 session key of length %d\n",
 518                            (int)KRB5_KEY_LENGTH(skey)));
 519                 gensec_krb5_state->session_key = data_blob_talloc(gensec_krb5_state,
 520                                                 KRB5_KEY_DATA(skey), KRB5_KEY_LENGTH(skey));
 521                 *session_key = gensec_krb5_state->session_key;
 522                 dump_data_pw("KRB5 Session Key:\n", session_key->data, session_key->length);
 523
 524                 krb5_free_keyblock(context, skey);
 525                 return NT_STATUS_OK;
 526         } else {
 527                 DEBUG(10, ("KRB5 error getting session key %d\n", err));
 528                 return NT_STATUS_NO_USER_SESSION_KEY;
 529         }
 530 }
 531
 532 static NTSTATUS gensec_krb5_session_info(struct gensec_security *gensec_security,
 533                                          struct auth_session_info **_session_info)
 534 {
 535         NTSTATUS nt_status = NT_STATUS_UNSUCCESSFUL;
 536         struct gensec_krb5_state *gensec_krb5_state = gensec_security->private_data;
 537         krb5_context context = gensec_krb5_state->smb_krb5_context->krb5_context;
 538         struct auth_serversupplied_info *server_info = NULL;
 539         struct auth_session_info *session_info = NULL;
 540         struct PAC_LOGON_INFO *logon_info;
 541
 542         krb5_principal client_principal;
 543         char *principal_string;
 544
 545         DATA_BLOB pac;
 546         krb5_data pac_data;
 547
 548         krb5_error_code ret;
 549
 550         TALLOC_CTX *mem_ctx = talloc_new(gensec_security);
 551         if (!mem_ctx) {
 552                 return NT_STATUS_NO_MEMORY;
 553         }
 554
 555         ret = krb5_ticket_get_client(context, gensec_krb5_state->ticket, &client_principal);
 556         if (ret) {
 557                 DEBUG(5, ("krb5_ticket_get_client failed to get cleint principal: %s\n",
 558                           smb_get_krb5_error_message(context,
 559                                                      ret, mem_ctx)));
 560                 talloc_free(mem_ctx);
 561                 return NT_STATUS_NO_MEMORY;
 562         }
 563
 564         ret = krb5_unparse_name(gensec_krb5_state->smb_krb5_context->krb5_context,
 565                                 client_principal, &principal_string);
 566         if (ret) {
 567                 DEBUG(1, ("Unable to parse client principal: %s\n",
 568                           smb_get_krb5_error_message(context,
 569                                                      ret, mem_ctx)));
 570                 talloc_free(mem_ctx);
 571                 return NT_STATUS_NO_MEMORY;
 572         }
 573
 574         ret = krb5_ticket_get_authorization_data_type(context, gensec_krb5_state->ticket,
 575                                                       KRB5_AUTHDATA_WIN2K_PAC,
 576                                                       &pac_data);
 577
 578         if (ret && lp_parm_bool(-1, "gensec", "require_pac", False)) {
 579                 DEBUG(1, ("Unable to find PAC in ticket from %s, failing to allow access: %s \n",
 580                           principal_string,
 581                           smb_get_krb5_error_message(context,
 582                                                      ret, mem_ctx)));
 583                 krb5_free_principal(context, client_principal);
 584                 free(principal_string);
 585                 return NT_STATUS_ACCESS_DENIED;
 586         } else if (ret) {
 587                 /* NO pac */
 588                 DEBUG(5, ("krb5_ticket_get_authorization_data_type failed to find PAC: %s\n",
 589                           smb_get_krb5_error_message(context,
 590                                                      ret, mem_ctx)));
 591                 nt_status = sam_get_server_info_principal(mem_ctx, principal_string,
 592                                                           &server_info);
 593                 krb5_free_principal(context, client_principal);
 594                 free(principal_string);
 595
 596                 if (!NT_STATUS_IS_OK(nt_status)) {
 597                         talloc_free(mem_ctx);
 598                         return nt_status;
 599                 }
 600         } else {
 601                 /* Found pac */
 602                 union netr_Validation validation;
 603                 free(principal_string);
 604
 605                 pac = data_blob_talloc(mem_ctx, pac_data.data, pac_data.length);
 606                 if (!pac.data) {
 607                         krb5_free_principal(context, client_principal);
 608                         talloc_free(mem_ctx);
 609                         return NT_STATUS_NO_MEMORY;
 610                 }
 611
 612                 /* decode and verify the pac */
 613                 nt_status = kerberos_pac_logon_info(gensec_krb5_state, &logon_info, pac,
 614                                                     gensec_krb5_state->smb_krb5_context->krb5_context,
 615                                                     NULL, gensec_krb5_state->keyblock,
 616                                                     client_principal,
 617                                                     gensec_krb5_state->ticket->ticket.authtime, NULL);
 618                 krb5_free_principal(context, client_principal);
 619
 620                 if (!NT_STATUS_IS_OK(nt_status)) {
 621                         talloc_free(mem_ctx);
 622                         return nt_status;
 623                 }
 624
 625                 validation.sam3 = &logon_info->info3;
 626                 nt_status = make_server_info_netlogon_validation(mem_ctx,
 627                                                                  NULL,
 628                                                                  3, &validation,
 629                                                                  &server_info);
 630                 if (!NT_STATUS_IS_OK(nt_status)) {
 631                         talloc_free(mem_ctx);
 632                         return nt_status;
 633                 }
 634         }
 635
 636         /* references the server_info into the session_info */
 637         nt_status = auth_generate_session_info(mem_ctx, server_info, &session_info);
 638
 639         if (!NT_STATUS_IS_OK(nt_status)) {
 640                 talloc_free(mem_ctx);
 641                 return nt_status;
 642         }
 643
 644         nt_status = gensec_krb5_session_key(gensec_security, &session_info->session_key);
 645
 646         if (!NT_STATUS_IS_OK(nt_status)) {
 647                 talloc_free(mem_ctx);
 648                 return nt_status;
 649         }
 650
 651         *_session_info = session_info;
 652
 653         talloc_steal(gensec_krb5_state, session_info);
 654         talloc_free(mem_ctx);
 655         return NT_STATUS_OK;
 656 }
 657
 658 static NTSTATUS gensec_krb5_wrap(struct gensec_security *gensec_security,
 659                                    TALLOC_CTX *mem_ctx,
 660                                    const DATA_BLOB *in,
 661                                    DATA_BLOB *out)
 662 {
 663         struct gensec_krb5_state *gensec_krb5_state = gensec_security->private_data;
 664         krb5_context context = gensec_krb5_state->smb_krb5_context->krb5_context;
 665         krb5_auth_context auth_context = gensec_krb5_state->auth_context;
 666         krb5_error_code ret;
 667         krb5_data input, output;
 668         input.length = in->length;
 669         input.data = in->data;
 670
 671         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
 672                 ret = krb5_mk_priv(context, auth_context, &input, &output, NULL);
 673                 if (ret) {
 674                         DEBUG(1, ("krb5_mk_priv failed: %s\n",
 675                                   smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context,
 676                                                              ret, mem_ctx)));
 677                         return NT_STATUS_ACCESS_DENIED;
 678                 }
 679                 *out = data_blob_talloc(mem_ctx, output.data, output.length);
 680
 681                 krb5_data_free(&output);
 682         } else {
 683                 return NT_STATUS_ACCESS_DENIED;
 684         }
 685         return NT_STATUS_OK;
 686 }
 687
 688 static NTSTATUS gensec_krb5_unwrap(struct gensec_security *gensec_security,
 689                                      TALLOC_CTX *mem_ctx,
 690                                      const DATA_BLOB *in,
 691                                      DATA_BLOB *out)
 692 {
 693         struct gensec_krb5_state *gensec_krb5_state = gensec_security->private_data;
 694         krb5_context context = gensec_krb5_state->smb_krb5_context->krb5_context;
 695         krb5_auth_context auth_context = gensec_krb5_state->auth_context;
 696         krb5_error_code ret;
 697         krb5_data input, output;
 698         krb5_replay_data replay;
 699         input.length = in->length;
 700         input.data = in->data;
 701
 702         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
 703                 ret = krb5_rd_priv(context, auth_context, &input, &output, &replay);
 704                 if (ret) {
 705                         DEBUG(1, ("krb5_rd_priv failed: %s\n",
 706                                   smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context,
 707                                                              ret, mem_ctx)));
 708                         return NT_STATUS_ACCESS_DENIED;
 709                 }
 710                 *out = data_blob_talloc(mem_ctx, output.data, output.length);
 711
 712                 krb5_data_free(&output);
 713         } else {
 714                 return NT_STATUS_ACCESS_DENIED;
 715         }
 716         return NT_STATUS_OK;
 717 }
 718
 719 static BOOL gensec_krb5_have_feature(struct gensec_security *gensec_security,
 720                                      uint32_t feature)
 721 {
 722         struct gensec_krb5_state *gensec_krb5_state = gensec_security->private_data;
 723         if (feature & GENSEC_FEATURE_SESSION_KEY) {
 724                 return True;
 725         }
 726         if (!gensec_krb5_state->gssapi &&
 727             (feature & GENSEC_FEATURE_SEAL)) {
 728                 return True;
 729         }
 730
 731         return False;
 732 }
 733
 734 static const char *gensec_krb5_oids[] = {
 735         GENSEC_OID_KERBEROS5,
 736         GENSEC_OID_KERBEROS5_OLD,
 737         NULL
 738 };
 739
 740 static const struct gensec_security_ops gensec_fake_gssapi_krb5_security_ops = {
 741         .name           = "fake_gssapi_krb5",
 742         .auth_type      = DCERPC_AUTH_TYPE_KRB5,
 743         .oid            = gensec_krb5_oids,
 744         .client_start   = gensec_fake_gssapi_krb5_client_start,
 745         .server_start   = gensec_fake_gssapi_krb5_server_start,
 746         .update         = gensec_krb5_update,
 747         .magic          = gensec_fake_gssapi_krb5_magic,
 748         .session_key    = gensec_krb5_session_key,
 749         .session_info   = gensec_krb5_session_info,
 750         .have_feature   = gensec_krb5_have_feature,
 751         .enabled        = False,
 752         .kerberos       = True,
 753         .priority       = GENSEC_KRB5
 754 };
 755
 756 static const struct gensec_security_ops gensec_krb5_security_ops = {
 757         .name           = "krb5",
 758         .client_start   = gensec_krb5_client_start,
 759         .server_start   = gensec_krb5_server_start,
 760         .update         = gensec_krb5_update,
 761         .session_key    = gensec_krb5_session_key,
 762         .session_info   = gensec_krb5_session_info,
 763         .have_feature   = gensec_krb5_have_feature,
 764         .wrap           = gensec_krb5_wrap,
 765         .unwrap         = gensec_krb5_unwrap,
 766         .enabled        = True,
 767         .kerberos       = True,
 768         .priority       = GENSEC_KRB5
 769 };
 770
 771 NTSTATUS gensec_krb5_init(void)
 772 {
 773         NTSTATUS ret;
 774
 775         auth_init();
 776
 777         ret = gensec_register(&gensec_krb5_security_ops);
 778         if (!NT_STATUS_IS_OK(ret)) {
 779                 DEBUG(0,("Failed to register '%s' gensec backend!\n",
 780                         gensec_krb5_security_ops.name));
 781                 return ret;
 782         }
 783
 784         ret = gensec_register(&gensec_fake_gssapi_krb5_security_ops);
 785         if (!NT_STATUS_IS_OK(ret)) {
 786                 DEBUG(0,("Failed to register '%s' gensec backend!\n",
 787                         gensec_krb5_security_ops.name));
 788                 return ret;
 789         }
 790
 791         return ret;
 792 }