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 3 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, see <http://www.gnu.org/licenses/>.
  24 */
  25
  26 #include "includes.h"
  27 #include "system/kerberos.h"
  28 #include "auth/kerberos/kerberos.h"
  29 #include "librpc/gen_ndr/krb5pac.h"
  30 #include "auth/auth.h"
  31 #include "lib/ldb/include/ldb.h"
  32 #include "auth/auth_sam.h"
  33 #include "system/network.h"
  34 #include "lib/socket/socket.h"
  35 #include "librpc/rpc/dcerpc.h"
  36 #include "auth/credentials/credentials.h"
  37 #include "auth/credentials/credentials_krb5.h"
  38 #include "auth/gensec/gensec.h"
  39 #include "param/param.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 = (struct 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 = (struct 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 = (struct gensec_krb5_state *)gensec_security->private_data;
 245         gensec_krb5_state->state_position = GENSEC_KRB5_CLIENT_START;
 246
 247         principal = gensec_get_target_principal(gensec_security);
 248
 249         ret = cli_credentials_get_ccache(gensec_get_credentials(gensec_security), &ccache_container);
 250         switch (ret) {
 251         case 0:
 252                 break;
 253         case KRB5KDC_ERR_PREAUTH_FAILED:
 254                 return NT_STATUS_LOGON_FAILURE;
 255         case KRB5_KDC_UNREACH:
 256                 DEBUG(3, ("Cannot reach a KDC we require to contact %s\n", principal));
 257                 return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
 258         default:
 259                 DEBUG(1, ("gensec_krb5_start: Aquiring initiator credentails failed: %s\n", error_message(ret)));
 260                 return NT_STATUS_UNSUCCESSFUL;
 261         }
 262         in_data.length = 0;
 263
 264         if (principal && lp_client_use_spnego_principal(global_loadparm)) {
 265                 krb5_principal target_principal;
 266                 ret = krb5_parse_name(gensec_krb5_state->smb_krb5_context->krb5_context, principal,
 267                                       &target_principal);
 268                 if (ret == 0) {
 269                         ret = krb5_mk_req_exact(gensec_krb5_state->smb_krb5_context->krb5_context,
 270                                                 &gensec_krb5_state->auth_context,
 271                                                 ap_req_options,
 272                                                 target_principal,
 273                                                 &in_data, ccache_container->ccache,
 274                                                 &gensec_krb5_state->enc_ticket);
 275                         krb5_free_principal(gensec_krb5_state->smb_krb5_context->krb5_context,
 276                                             target_principal);
 277                 }
 278         } else {
 279                 ret = krb5_mk_req(gensec_krb5_state->smb_krb5_context->krb5_context,
 280                                   &gensec_krb5_state->auth_context,
 281                                   ap_req_options,
 282                                   gensec_get_target_service(gensec_security),
 283                                   hostname,
 284                                   &in_data, ccache_container->ccache,
 285                                   &gensec_krb5_state->enc_ticket);
 286         }
 287         switch (ret) {
 288         case 0:
 289                 return NT_STATUS_OK;
 290         case KRB5KDC_ERR_S_PRINCIPAL_UNKNOWN:
 291                 DEBUG(3, ("Server [%s] is not registered with our KDC: %s\n",
 292                           hostname, smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context, ret, gensec_krb5_state)));
 293                 return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
 294         case KRB5_KDC_UNREACH:
 295                 DEBUG(3, ("Cannot reach a KDC we require to contact host [%s]: %s\n",
 296                           hostname, smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context, ret, gensec_krb5_state)));
 297                 return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
 298         case KRB5KDC_ERR_PREAUTH_FAILED:
 299         case KRB5KRB_AP_ERR_TKT_EXPIRED:
 300         case KRB5_CC_END:
 301                 /* Too much clock skew - we will need to kinit to re-skew the clock */
 302         case KRB5KRB_AP_ERR_SKEW:
 303         case KRB5_KDCREP_SKEW:
 304         {
 305                 DEBUG(3, ("kerberos (mk_req) failed: %s\n",
 306                           smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context, ret, gensec_krb5_state)));
 307                 /*fall through*/
 308         }
 309
 310         /* just don't print a message for these really ordinary messages */
 311         case KRB5_FCC_NOFILE:
 312         case KRB5_CC_NOTFOUND:
 313         case ENOENT:
 314
 315                 return NT_STATUS_UNSUCCESSFUL;
 316                 break;
 317
 318         default:
 319                 DEBUG(0, ("kerberos: %s\n",
 320                           smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context, ret, gensec_krb5_state)));
 321                 return NT_STATUS_UNSUCCESSFUL;
 322         }
 323 }
 324
 325 static NTSTATUS gensec_fake_gssapi_krb5_client_start(struct gensec_security *gensec_security)
 326 {
 327         NTSTATUS nt_status = gensec_krb5_client_start(gensec_security);
 328
 329         if (NT_STATUS_IS_OK(nt_status)) {
 330                 struct gensec_krb5_state *gensec_krb5_state;
 331                 gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
 332                 gensec_krb5_state->gssapi = true;
 333         }
 334         return nt_status;
 335 }
 336
 337 /**
 338  * Check if the packet is one for this mechansim
 339  *
 340  * @param gensec_security GENSEC state
 341  * @param in The request, as a DATA_BLOB
 342  * @return Error, INVALID_PARAMETER if it's not a packet for us
 343  *                or NT_STATUS_OK if the packet is ok.
 344  */
 345
 346 static NTSTATUS gensec_fake_gssapi_krb5_magic(struct gensec_security *gensec_security,
 347                                   const DATA_BLOB *in)
 348 {
 349         if (gensec_gssapi_check_oid(in, GENSEC_OID_KERBEROS5)) {
 350                 return NT_STATUS_OK;
 351         } else {
 352                 return NT_STATUS_INVALID_PARAMETER;
 353         }
 354 }
 355
 356
 357 /**
 358  * Next state function for the Krb5 GENSEC mechanism
 359  *
 360  * @param gensec_krb5_state KRB5 State
 361  * @param out_mem_ctx The TALLOC_CTX for *out to be allocated on
 362  * @param in The request, as a DATA_BLOB
 363  * @param out The reply, as an talloc()ed DATA_BLOB, on *out_mem_ctx
 364  * @return Error, MORE_PROCESSING_REQUIRED if a reply is sent,
 365  *                or NT_STATUS_OK if the user is authenticated.
 366  */
 367
 368 static NTSTATUS gensec_krb5_update(struct gensec_security *gensec_security,
 369                                    TALLOC_CTX *out_mem_ctx,
 370                                    const DATA_BLOB in, DATA_BLOB *out)
 371 {
 372         struct gensec_krb5_state *gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
 373         krb5_error_code ret = 0;
 374         NTSTATUS nt_status;
 375
 376         switch (gensec_krb5_state->state_position) {
 377         case GENSEC_KRB5_CLIENT_START:
 378         {
 379                 DATA_BLOB unwrapped_out;
 380
 381                 if (gensec_krb5_state->gssapi) {
 382                         unwrapped_out = data_blob_talloc(out_mem_ctx, gensec_krb5_state->enc_ticket.data, gensec_krb5_state->enc_ticket.length);
 383
 384                         /* wrap that up in a nice GSS-API wrapping */
 385                         *out = gensec_gssapi_gen_krb5_wrap(out_mem_ctx, &unwrapped_out, TOK_ID_KRB_AP_REQ);
 386                 } else {
 387                         *out = data_blob_talloc(out_mem_ctx, gensec_krb5_state->enc_ticket.data, gensec_krb5_state->enc_ticket.length);
 388                 }
 389                 gensec_krb5_state->state_position = GENSEC_KRB5_CLIENT_MUTUAL_AUTH;
 390                 nt_status = NT_STATUS_MORE_PROCESSING_REQUIRED;
 391                 return nt_status;
 392         }
 393
 394         case GENSEC_KRB5_CLIENT_MUTUAL_AUTH:
 395         {
 396                 DATA_BLOB unwrapped_in;
 397                 krb5_data inbuf;
 398                 krb5_ap_rep_enc_part *repl = NULL;
 399                 uint8_t tok_id[2];
 400
 401                 if (gensec_krb5_state->gssapi) {
 402                         if (!gensec_gssapi_parse_krb5_wrap(out_mem_ctx, &in, &unwrapped_in, tok_id)) {
 403                                 DEBUG(1,("gensec_gssapi_parse_krb5_wrap(mutual authentication) failed to parse\n"));
 404                                 dump_data_pw("Mutual authentication message:\n", in.data, in.length);
 405                                 return NT_STATUS_INVALID_PARAMETER;
 406                         }
 407                 } else {
 408                         unwrapped_in = in;
 409                 }
 410                 /* TODO: check the tok_id */
 411
 412                 inbuf.data = unwrapped_in.data;
 413                 inbuf.length = unwrapped_in.length;
 414                 ret = krb5_rd_rep(gensec_krb5_state->smb_krb5_context->krb5_context,
 415                                   gensec_krb5_state->auth_context,
 416                                   &inbuf, &repl);
 417                 if (ret) {
 418                         DEBUG(1,("krb5_rd_rep (mutual authentication) failed (%s)\n",
 419                                  smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context, ret, out_mem_ctx)));
 420                         dump_data_pw("Mutual authentication message:\n", (uint8_t *)inbuf.data, inbuf.length);
 421                         nt_status = NT_STATUS_ACCESS_DENIED;
 422                 } else {
 423                         *out = data_blob(NULL, 0);
 424                         nt_status = NT_STATUS_OK;
 425                         gensec_krb5_state->state_position = GENSEC_KRB5_DONE;
 426                 }
 427                 if (repl) {
 428                         krb5_free_ap_rep_enc_part(gensec_krb5_state->smb_krb5_context->krb5_context, repl);
 429                 }
 430                 return nt_status;
 431         }
 432
 433         case GENSEC_KRB5_SERVER_START:
 434         {
 435                 DATA_BLOB unwrapped_in;
 436                 DATA_BLOB unwrapped_out = data_blob(NULL, 0);
 437                 krb5_data inbuf, outbuf;
 438                 uint8_t tok_id[2];
 439                 struct keytab_container *keytab;
 440                 krb5_principal server_in_keytab;
 441
 442                 if (!in.data) {
 443                         return NT_STATUS_INVALID_PARAMETER;
 444                 }
 445
 446                 /* Grab the keytab, however generated */
 447                 ret = cli_credentials_get_keytab(gensec_get_credentials(gensec_security), &keytab);
 448                 if (ret) {
 449                         return NT_STATUS_CANT_ACCESS_DOMAIN_INFO;
 450                 }
 451
 452                 /* This ensures we lookup the correct entry in that keytab */
 453                 ret = principal_from_credentials(out_mem_ctx, gensec_get_credentials(gensec_security),
 454                                                  gensec_krb5_state->smb_krb5_context,
 455                                                  &server_in_keytab);
 456
 457                 if (ret) {
 458                         return NT_STATUS_CANT_ACCESS_DOMAIN_INFO;
 459                 }
 460
 461                 /* Parse the GSSAPI wrapping, if it's there... (win2k3 allows it to be omited) */
 462                 if (gensec_krb5_state->gssapi
 463                     && gensec_gssapi_parse_krb5_wrap(out_mem_ctx, &in, &unwrapped_in, tok_id)) {
 464                         inbuf.data = unwrapped_in.data;
 465                         inbuf.length = unwrapped_in.length;
 466                 } else {
 467                         inbuf.data = in.data;
 468                         inbuf.length = in.length;
 469                 }
 470
 471                 ret = smb_rd_req_return_stuff(gensec_krb5_state->smb_krb5_context->krb5_context,
 472                                               &gensec_krb5_state->auth_context,
 473                                               &inbuf, keytab->keytab, server_in_keytab,
 474                                               &outbuf,
 475                                               &gensec_krb5_state->ticket,
 476                                               &gensec_krb5_state->keyblock);
 477
 478                 if (ret) {
 479                         return NT_STATUS_LOGON_FAILURE;
 480                 }
 481                 unwrapped_out.data = (uint8_t *)outbuf.data;
 482                 unwrapped_out.length = outbuf.length;
 483                 gensec_krb5_state->state_position = GENSEC_KRB5_DONE;
 484                 /* wrap that up in a nice GSS-API wrapping */
 485                 if (gensec_krb5_state->gssapi) {
 486                         *out = gensec_gssapi_gen_krb5_wrap(out_mem_ctx, &unwrapped_out, TOK_ID_KRB_AP_REP);
 487                 } else {
 488                         *out = data_blob_talloc(out_mem_ctx, outbuf.data, outbuf.length);
 489                 }
 490                 krb5_data_free(&outbuf);
 491                 return NT_STATUS_OK;
 492         }
 493
 494         case GENSEC_KRB5_DONE:
 495         default:
 496                 /* Asking too many times... */
 497                 return NT_STATUS_INVALID_PARAMETER;
 498         }
 499 }
 500
 501 static NTSTATUS gensec_krb5_session_key(struct gensec_security *gensec_security,
 502                                         DATA_BLOB *session_key)
 503 {
 504         struct gensec_krb5_state *gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
 505         krb5_context context = gensec_krb5_state->smb_krb5_context->krb5_context;
 506         krb5_auth_context auth_context = gensec_krb5_state->auth_context;
 507         krb5_keyblock *skey;
 508         krb5_error_code err = -1;
 509
 510         if (gensec_krb5_state->session_key.data) {
 511                 *session_key = gensec_krb5_state->session_key;
 512                 return NT_STATUS_OK;
 513         }
 514
 515         switch (gensec_security->gensec_role) {
 516         case GENSEC_CLIENT:
 517                 err = krb5_auth_con_getlocalsubkey(context, auth_context, &skey);
 518                 break;
 519         case GENSEC_SERVER:
 520                 err = krb5_auth_con_getremotesubkey(context, auth_context, &skey);
 521                 break;
 522         }
 523         if (err == 0 && skey != NULL) {
 524                 DEBUG(10, ("Got KRB5 session key of length %d\n",
 525                            (int)KRB5_KEY_LENGTH(skey)));
 526                 gensec_krb5_state->session_key = data_blob_talloc(gensec_krb5_state,
 527                                                 KRB5_KEY_DATA(skey), KRB5_KEY_LENGTH(skey));
 528                 *session_key = gensec_krb5_state->session_key;
 529                 dump_data_pw("KRB5 Session Key:\n", session_key->data, session_key->length);
 530
 531                 krb5_free_keyblock(context, skey);
 532                 return NT_STATUS_OK;
 533         } else {
 534                 DEBUG(10, ("KRB5 error getting session key %d\n", err));
 535                 return NT_STATUS_NO_USER_SESSION_KEY;
 536         }
 537 }
 538
 539 static NTSTATUS gensec_krb5_session_info(struct gensec_security *gensec_security,
 540                                          struct auth_session_info **_session_info)
 541 {
 542         NTSTATUS nt_status = NT_STATUS_UNSUCCESSFUL;
 543         struct gensec_krb5_state *gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
 544         krb5_context context = gensec_krb5_state->smb_krb5_context->krb5_context;
 545         struct auth_serversupplied_info *server_info = NULL;
 546         struct auth_session_info *session_info = NULL;
 547         struct PAC_LOGON_INFO *logon_info;
 548
 549         krb5_principal client_principal;
 550         char *principal_string;
 551
 552         DATA_BLOB pac;
 553         krb5_data pac_data;
 554
 555         krb5_error_code ret;
 556
 557         TALLOC_CTX *mem_ctx = talloc_new(gensec_security);
 558         if (!mem_ctx) {
 559                 return NT_STATUS_NO_MEMORY;
 560         }
 561
 562         ret = krb5_ticket_get_client(context, gensec_krb5_state->ticket, &client_principal);
 563         if (ret) {
 564                 DEBUG(5, ("krb5_ticket_get_client failed to get cleint principal: %s\n",
 565                           smb_get_krb5_error_message(context,
 566                                                      ret, mem_ctx)));
 567                 talloc_free(mem_ctx);
 568                 return NT_STATUS_NO_MEMORY;
 569         }
 570
 571         ret = krb5_unparse_name(gensec_krb5_state->smb_krb5_context->krb5_context,
 572                                 client_principal, &principal_string);
 573         if (ret) {
 574                 DEBUG(1, ("Unable to parse client principal: %s\n",
 575                           smb_get_krb5_error_message(context,
 576                                                      ret, mem_ctx)));
 577                 talloc_free(mem_ctx);
 578                 return NT_STATUS_NO_MEMORY;
 579         }
 580
 581         ret = krb5_ticket_get_authorization_data_type(context, gensec_krb5_state->ticket,
 582                                                       KRB5_AUTHDATA_WIN2K_PAC,
 583                                                       &pac_data);
 584
 585         if (ret && lp_parm_bool(global_loadparm, NULL, "gensec", "require_pac", false)) {
 586                 DEBUG(1, ("Unable to find PAC in ticket from %s, failing to allow access: %s \n",
 587                           principal_string,
 588                           smb_get_krb5_error_message(context,
 589                                                      ret, mem_ctx)));
 590                 krb5_free_principal(context, client_principal);
 591                 free(principal_string);
 592                 return NT_STATUS_ACCESS_DENIED;
 593         } else if (ret) {
 594                 /* NO pac */
 595                 DEBUG(5, ("krb5_ticket_get_authorization_data_type failed to find PAC: %s\n",
 596                           smb_get_krb5_error_message(context,
 597                                                      ret, mem_ctx)));
 598                 nt_status = sam_get_server_info_principal(mem_ctx, principal_string,
 599                                                           &server_info);
 600                 krb5_free_principal(context, client_principal);
 601                 free(principal_string);
 602
 603                 if (!NT_STATUS_IS_OK(nt_status)) {
 604                         talloc_free(mem_ctx);
 605                         return nt_status;
 606                 }
 607         } else {
 608                 /* Found pac */
 609                 union netr_Validation validation;
 610                 free(principal_string);
 611
 612                 pac = data_blob_talloc(mem_ctx, pac_data.data, pac_data.length);
 613                 if (!pac.data) {
 614                         krb5_free_principal(context, client_principal);
 615                         talloc_free(mem_ctx);
 616                         return NT_STATUS_NO_MEMORY;
 617                 }
 618
 619                 /* decode and verify the pac */
 620                 nt_status = kerberos_pac_logon_info(gensec_krb5_state, &logon_info, pac,
 621                                                     gensec_krb5_state->smb_krb5_context->krb5_context,
 622                                                     NULL, gensec_krb5_state->keyblock,
 623                                                     client_principal,
 624                                                     gensec_krb5_state->ticket->ticket.authtime, NULL);
 625                 krb5_free_principal(context, client_principal);
 626
 627                 if (!NT_STATUS_IS_OK(nt_status)) {
 628                         talloc_free(mem_ctx);
 629                         return nt_status;
 630                 }
 631
 632                 validation.sam3 = &logon_info->info3;
 633                 nt_status = make_server_info_netlogon_validation(mem_ctx,
 634                                                                  NULL,
 635                                                                  3, &validation,
 636                                                                  &server_info);
 637                 if (!NT_STATUS_IS_OK(nt_status)) {
 638                         talloc_free(mem_ctx);
 639                         return nt_status;
 640                 }
 641         }
 642
 643         /* references the server_info into the session_info */
 644         nt_status = auth_generate_session_info(mem_ctx, server_info, &session_info);
 645
 646         if (!NT_STATUS_IS_OK(nt_status)) {
 647                 talloc_free(mem_ctx);
 648                 return nt_status;
 649         }
 650
 651         nt_status = gensec_krb5_session_key(gensec_security, &session_info->session_key);
 652
 653         if (!NT_STATUS_IS_OK(nt_status)) {
 654                 talloc_free(mem_ctx);
 655                 return nt_status;
 656         }
 657
 658         *_session_info = session_info;
 659
 660         talloc_steal(gensec_krb5_state, session_info);
 661         talloc_free(mem_ctx);
 662         return NT_STATUS_OK;
 663 }
 664
 665 static NTSTATUS gensec_krb5_wrap(struct gensec_security *gensec_security,
 666                                    TALLOC_CTX *mem_ctx,
 667                                    const DATA_BLOB *in,
 668                                    DATA_BLOB *out)
 669 {
 670         struct gensec_krb5_state *gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
 671         krb5_context context = gensec_krb5_state->smb_krb5_context->krb5_context;
 672         krb5_auth_context auth_context = gensec_krb5_state->auth_context;
 673         krb5_error_code ret;
 674         krb5_data input, output;
 675         input.length = in->length;
 676         input.data = in->data;
 677
 678         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
 679                 ret = krb5_mk_priv(context, auth_context, &input, &output, NULL);
 680                 if (ret) {
 681                         DEBUG(1, ("krb5_mk_priv failed: %s\n",
 682                                   smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context,
 683                                                              ret, mem_ctx)));
 684                         return NT_STATUS_ACCESS_DENIED;
 685                 }
 686                 *out = data_blob_talloc(mem_ctx, output.data, output.length);
 687
 688                 krb5_data_free(&output);
 689         } else {
 690                 return NT_STATUS_ACCESS_DENIED;
 691         }
 692         return NT_STATUS_OK;
 693 }
 694
 695 static NTSTATUS gensec_krb5_unwrap(struct gensec_security *gensec_security,
 696                                      TALLOC_CTX *mem_ctx,
 697                                      const DATA_BLOB *in,
 698                                      DATA_BLOB *out)
 699 {
 700         struct gensec_krb5_state *gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
 701         krb5_context context = gensec_krb5_state->smb_krb5_context->krb5_context;
 702         krb5_auth_context auth_context = gensec_krb5_state->auth_context;
 703         krb5_error_code ret;
 704         krb5_data input, output;
 705         krb5_replay_data replay;
 706         input.length = in->length;
 707         input.data = in->data;
 708
 709         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
 710                 ret = krb5_rd_priv(context, auth_context, &input, &output, &replay);
 711                 if (ret) {
 712                         DEBUG(1, ("krb5_rd_priv failed: %s\n",
 713                                   smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context,
 714                                                              ret, mem_ctx)));
 715                         return NT_STATUS_ACCESS_DENIED;
 716                 }
 717                 *out = data_blob_talloc(mem_ctx, output.data, output.length);
 718
 719                 krb5_data_free(&output);
 720         } else {
 721                 return NT_STATUS_ACCESS_DENIED;
 722         }
 723         return NT_STATUS_OK;
 724 }
 725
 726 static bool gensec_krb5_have_feature(struct gensec_security *gensec_security,
 727                                      uint32_t feature)
 728 {
 729         struct gensec_krb5_state *gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
 730         if (feature & GENSEC_FEATURE_SESSION_KEY) {
 731                 return true;
 732         }
 733         if (!gensec_krb5_state->gssapi &&
 734             (feature & GENSEC_FEATURE_SEAL)) {
 735                 return true;
 736         }
 737
 738         return false;
 739 }
 740
 741 static const char *gensec_krb5_oids[] = {
 742         GENSEC_OID_KERBEROS5,
 743         GENSEC_OID_KERBEROS5_OLD,
 744         NULL
 745 };
 746
 747 static const struct gensec_security_ops gensec_fake_gssapi_krb5_security_ops = {
 748         .name           = "fake_gssapi_krb5",
 749         .auth_type      = DCERPC_AUTH_TYPE_KRB5,
 750         .oid            = gensec_krb5_oids,
 751         .client_start   = gensec_fake_gssapi_krb5_client_start,
 752         .server_start   = gensec_fake_gssapi_krb5_server_start,
 753         .update         = gensec_krb5_update,
 754         .magic          = gensec_fake_gssapi_krb5_magic,
 755         .session_key    = gensec_krb5_session_key,
 756         .session_info   = gensec_krb5_session_info,
 757         .have_feature   = gensec_krb5_have_feature,
 758         .enabled        = false,
 759         .kerberos       = true,
 760         .priority       = GENSEC_KRB5
 761 };
 762
 763 static const struct gensec_security_ops gensec_krb5_security_ops = {
 764         .name           = "krb5",
 765         .client_start   = gensec_krb5_client_start,
 766         .server_start   = gensec_krb5_server_start,
 767         .update         = gensec_krb5_update,
 768         .session_key    = gensec_krb5_session_key,
 769         .session_info   = gensec_krb5_session_info,
 770         .have_feature   = gensec_krb5_have_feature,
 771         .wrap           = gensec_krb5_wrap,
 772         .unwrap         = gensec_krb5_unwrap,
 773         .enabled        = true,
 774         .kerberos       = true,
 775         .priority       = GENSEC_KRB5
 776 };
 777
 778 NTSTATUS gensec_krb5_init(void)
 779 {
 780         NTSTATUS ret;
 781
 782         auth_init(global_loadparm);
 783
 784         ret = gensec_register(&gensec_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         ret = gensec_register(&gensec_fake_gssapi_krb5_security_ops);
 792         if (!NT_STATUS_IS_OK(ret)) {
 793                 DEBUG(0,("Failed to register '%s' gensec backend!\n",
 794                         gensec_krb5_security_ops.name));
 795                 return ret;
 796         }
 797
 798         return ret;
 799 }