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 "lib/socket/socket.h"
  34 #include "librpc/rpc/dcerpc.h"
  35 #include "auth/credentials/credentials.h"
  36 #include "auth/credentials/credentials_krb5.h"
  37 #include "auth/gensec/gensec.h"
  38 #include "auth/gensec/gensec_proto.h"
  39 #include "param/param.h"
  40 #include "auth/session_proto.h"
  41 #include "auth/auth_sam_reply.h"
  42
  43 enum GENSEC_KRB5_STATE {
  44         GENSEC_KRB5_SERVER_START,
  45         GENSEC_KRB5_CLIENT_START,
  46         GENSEC_KRB5_CLIENT_MUTUAL_AUTH,
  47         GENSEC_KRB5_DONE
  48 };
  49
  50 struct gensec_krb5_state {
  51         DATA_BLOB session_key;
  52         DATA_BLOB pac;
  53         enum GENSEC_KRB5_STATE state_position;
  54         struct smb_krb5_context *smb_krb5_context;
  55         krb5_auth_context auth_context;
  56         krb5_data enc_ticket;
  57         krb5_keyblock *keyblock;
  58         krb5_ticket *ticket;
  59         bool gssapi;
  60         krb5_flags ap_req_options;
  61 };
  62
  63 static int gensec_krb5_destroy(struct gensec_krb5_state *gensec_krb5_state)
  64 {
  65         if (!gensec_krb5_state->smb_krb5_context) {
  66                 /* We can't clean anything else up unless we started up this far */
  67                 return 0;
  68         }
  69         if (gensec_krb5_state->enc_ticket.length) {
  70                 kerberos_free_data_contents(gensec_krb5_state->smb_krb5_context->krb5_context,
  71                                             &gensec_krb5_state->enc_ticket);
  72         }
  73
  74         if (gensec_krb5_state->ticket) {
  75                 krb5_free_ticket(gensec_krb5_state->smb_krb5_context->krb5_context,
  76                                  gensec_krb5_state->ticket);
  77         }
  78
  79         /* ccache freed in a child destructor */
  80
  81         krb5_free_keyblock(gensec_krb5_state->smb_krb5_context->krb5_context,
  82                            gensec_krb5_state->keyblock);
  83
  84         if (gensec_krb5_state->auth_context) {
  85                 krb5_auth_con_free(gensec_krb5_state->smb_krb5_context->krb5_context,
  86                                    gensec_krb5_state->auth_context);
  87         }
  88
  89         return 0;
  90 }
  91
  92 static NTSTATUS gensec_krb5_start(struct gensec_security *gensec_security)
  93 {
  94         krb5_error_code ret;
  95         struct gensec_krb5_state *gensec_krb5_state;
  96         struct cli_credentials *creds;
  97         const struct socket_address *my_addr, *peer_addr;
  98         krb5_address my_krb5_addr, peer_krb5_addr;
  99
 100         creds = gensec_get_credentials(gensec_security);
 101         if (!creds) {
 102                 return NT_STATUS_INVALID_PARAMETER;
 103         }
 104
 105         gensec_krb5_state = talloc(gensec_security, struct gensec_krb5_state);
 106         if (!gensec_krb5_state) {
 107                 return NT_STATUS_NO_MEMORY;
 108         }
 109
 110         gensec_security->private_data = gensec_krb5_state;
 111         gensec_krb5_state->smb_krb5_context = NULL;
 112         gensec_krb5_state->auth_context = NULL;
 113         gensec_krb5_state->ticket = NULL;
 114         ZERO_STRUCT(gensec_krb5_state->enc_ticket);
 115         gensec_krb5_state->keyblock = NULL;
 116         gensec_krb5_state->session_key = data_blob(NULL, 0);
 117         gensec_krb5_state->pac = data_blob(NULL, 0);
 118         gensec_krb5_state->gssapi = false;
 119
 120         talloc_set_destructor(gensec_krb5_state, gensec_krb5_destroy);
 121
 122         if (cli_credentials_get_krb5_context(creds,
 123                                              gensec_security->event_ctx,
 124                                              gensec_security->settings->lp_ctx, &gensec_krb5_state->smb_krb5_context)) {
 125                 talloc_free(gensec_krb5_state);
 126                 return NT_STATUS_INTERNAL_ERROR;
 127         }
 128
 129         ret = krb5_auth_con_init(gensec_krb5_state->smb_krb5_context->krb5_context, &gensec_krb5_state->auth_context);
 130         if (ret) {
 131                 DEBUG(1,("gensec_krb5_start: krb5_auth_con_init failed (%s)\n",
 132                          smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context,
 133                                                     ret, gensec_krb5_state)));
 134                 talloc_free(gensec_krb5_state);
 135                 return NT_STATUS_INTERNAL_ERROR;
 136         }
 137
 138         ret = krb5_auth_con_setflags(gensec_krb5_state->smb_krb5_context->krb5_context,
 139                                      gensec_krb5_state->auth_context,
 140                                      KRB5_AUTH_CONTEXT_DO_SEQUENCE);
 141         if (ret) {
 142                 DEBUG(1,("gensec_krb5_start: krb5_auth_con_setflags failed (%s)\n",
 143                          smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context,
 144                                                     ret, gensec_krb5_state)));
 145                 talloc_free(gensec_krb5_state);
 146                 return NT_STATUS_INTERNAL_ERROR;
 147         }
 148
 149         my_addr = gensec_get_my_addr(gensec_security);
 150         if (my_addr && my_addr->sockaddr) {
 151                 ret = krb5_sockaddr2address(gensec_krb5_state->smb_krb5_context->krb5_context,
 152                                             my_addr->sockaddr, &my_krb5_addr);
 153                 if (ret) {
 154                         DEBUG(1,("gensec_krb5_start: krb5_sockaddr2address (local) failed (%s)\n",
 155                                  smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context,
 156                                                             ret, gensec_krb5_state)));
 157                         talloc_free(gensec_krb5_state);
 158                         return NT_STATUS_INTERNAL_ERROR;
 159                 }
 160         }
 161
 162         peer_addr = gensec_get_peer_addr(gensec_security);
 163         if (peer_addr && peer_addr->sockaddr) {
 164                 ret = krb5_sockaddr2address(gensec_krb5_state->smb_krb5_context->krb5_context,
 165                                             peer_addr->sockaddr, &peer_krb5_addr);
 166                 if (ret) {
 167                         DEBUG(1,("gensec_krb5_start: krb5_sockaddr2address (local) failed (%s)\n",
 168                                  smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context,
 169                                                             ret, gensec_krb5_state)));
 170                         talloc_free(gensec_krb5_state);
 171                         return NT_STATUS_INTERNAL_ERROR;
 172                 }
 173         }
 174
 175         ret = krb5_auth_con_setaddrs(gensec_krb5_state->smb_krb5_context->krb5_context,
 176                                      gensec_krb5_state->auth_context,
 177                                      my_addr ? &my_krb5_addr : NULL,
 178                                      peer_addr ? &peer_krb5_addr : NULL);
 179         if (ret) {
 180                 DEBUG(1,("gensec_krb5_start: krb5_auth_con_setaddrs failed (%s)\n",
 181                          smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context,
 182                                                     ret, gensec_krb5_state)));
 183                 talloc_free(gensec_krb5_state);
 184                 return NT_STATUS_INTERNAL_ERROR;
 185         }
 186
 187         return NT_STATUS_OK;
 188 }
 189
 190 static NTSTATUS gensec_krb5_server_start(struct gensec_security *gensec_security)
 191 {
 192         NTSTATUS nt_status;
 193         struct gensec_krb5_state *gensec_krb5_state;
 194
 195         nt_status = gensec_krb5_start(gensec_security);
 196         if (!NT_STATUS_IS_OK(nt_status)) {
 197                 return nt_status;
 198         }
 199
 200         gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
 201         gensec_krb5_state->state_position = GENSEC_KRB5_SERVER_START;
 202
 203         return NT_STATUS_OK;
 204 }
 205
 206 static NTSTATUS gensec_fake_gssapi_krb5_server_start(struct gensec_security *gensec_security)
 207 {
 208         NTSTATUS nt_status = gensec_krb5_server_start(gensec_security);
 209
 210         if (NT_STATUS_IS_OK(nt_status)) {
 211                 struct gensec_krb5_state *gensec_krb5_state;
 212                 gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
 213                 gensec_krb5_state->gssapi = true;
 214         }
 215         return nt_status;
 216 }
 217
 218 static NTSTATUS gensec_krb5_client_start(struct gensec_security *gensec_security)
 219 {
 220         struct gensec_krb5_state *gensec_krb5_state;
 221         krb5_error_code ret;
 222         NTSTATUS nt_status;
 223         struct ccache_container *ccache_container;
 224         const char *hostname;
 225
 226         const char *principal;
 227         krb5_data in_data;
 228
 229         hostname = gensec_get_target_hostname(gensec_security);
 230         if (!hostname) {
 231                 DEBUG(1, ("Could not determine hostname for target computer, cannot use kerberos\n"));
 232                 return NT_STATUS_INVALID_PARAMETER;
 233         }
 234         if (is_ipaddress(hostname)) {
 235                 DEBUG(2, ("Cannot do krb5 to an IP address"));
 236                 return NT_STATUS_INVALID_PARAMETER;
 237         }
 238         if (strcmp(hostname, "localhost") == 0) {
 239                 DEBUG(2, ("krb5 to 'localhost' does not make sense"));
 240                 return NT_STATUS_INVALID_PARAMETER;
 241         }
 242
 243         nt_status = gensec_krb5_start(gensec_security);
 244         if (!NT_STATUS_IS_OK(nt_status)) {
 245                 return nt_status;
 246         }
 247
 248         gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
 249         gensec_krb5_state->state_position = GENSEC_KRB5_CLIENT_START;
 250         gensec_krb5_state->ap_req_options = AP_OPTS_USE_SUBKEY;
 251
 252         if (gensec_setting_bool(gensec_security->settings, "gensec_krb5", "mutual", true)) {
 253                 gensec_krb5_state->ap_req_options |= AP_OPTS_MUTUAL_REQUIRED;
 254         }
 255
 256         principal = gensec_get_target_principal(gensec_security);
 257
 258         ret = cli_credentials_get_ccache(gensec_get_credentials(gensec_security),
 259                                          gensec_security->event_ctx,
 260                                          gensec_security->settings->lp_ctx, &ccache_container);
 261         switch (ret) {
 262         case 0:
 263                 break;
 264         case KRB5KDC_ERR_PREAUTH_FAILED:
 265                 return NT_STATUS_LOGON_FAILURE;
 266         case KRB5_KDC_UNREACH:
 267                 DEBUG(3, ("Cannot reach a KDC we require to contact %s\n", principal));
 268                 return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
 269         default:
 270                 DEBUG(1, ("gensec_krb5_start: Aquiring initiator credentials failed: %s\n", error_message(ret)));
 271                 return NT_STATUS_UNSUCCESSFUL;
 272         }
 273         in_data.length = 0;
 274
 275         if (principal && lp_client_use_spnego_principal(gensec_security->settings->lp_ctx)) {
 276                 krb5_principal target_principal;
 277                 ret = krb5_parse_name(gensec_krb5_state->smb_krb5_context->krb5_context, principal,
 278                                       &target_principal);
 279                 if (ret == 0) {
 280                         ret = krb5_mk_req_exact(gensec_krb5_state->smb_krb5_context->krb5_context,
 281                                                 &gensec_krb5_state->auth_context,
 282                                                 gensec_krb5_state->ap_req_options,
 283                                                 target_principal,
 284                                                 &in_data, ccache_container->ccache,
 285                                                 &gensec_krb5_state->enc_ticket);
 286                         krb5_free_principal(gensec_krb5_state->smb_krb5_context->krb5_context,
 287                                             target_principal);
 288                 }
 289         } else {
 290                 ret = krb5_mk_req(gensec_krb5_state->smb_krb5_context->krb5_context,
 291                                   &gensec_krb5_state->auth_context,
 292                                   gensec_krb5_state->ap_req_options,
 293                                   gensec_get_target_service(gensec_security),
 294                                   hostname,
 295                                   &in_data, ccache_container->ccache,
 296                                   &gensec_krb5_state->enc_ticket);
 297         }
 298         switch (ret) {
 299         case 0:
 300                 return NT_STATUS_OK;
 301         case KRB5KDC_ERR_S_PRINCIPAL_UNKNOWN:
 302                 DEBUG(3, ("Server [%s] is not registered with our KDC: %s\n",
 303                           hostname, smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context, ret, gensec_krb5_state)));
 304                 return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
 305         case KRB5_KDC_UNREACH:
 306                 DEBUG(3, ("Cannot reach a KDC we require to contact host [%s]: %s\n",
 307                           hostname, smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context, ret, gensec_krb5_state)));
 308                 return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
 309         case KRB5KDC_ERR_PREAUTH_FAILED:
 310         case KRB5KRB_AP_ERR_TKT_EXPIRED:
 311         case KRB5_CC_END:
 312                 /* Too much clock skew - we will need to kinit to re-skew the clock */
 313         case KRB5KRB_AP_ERR_SKEW:
 314         case KRB5_KDCREP_SKEW:
 315         {
 316                 DEBUG(3, ("kerberos (mk_req) failed: %s\n",
 317                           smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context, ret, gensec_krb5_state)));
 318                 /*fall through*/
 319         }
 320
 321         /* just don't print a message for these really ordinary messages */
 322         case KRB5_FCC_NOFILE:
 323         case KRB5_CC_NOTFOUND:
 324         case ENOENT:
 325
 326                 return NT_STATUS_UNSUCCESSFUL;
 327                 break;
 328
 329         default:
 330                 DEBUG(0, ("kerberos: %s\n",
 331                           smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context, ret, gensec_krb5_state)));
 332                 return NT_STATUS_UNSUCCESSFUL;
 333         }
 334 }
 335
 336 static NTSTATUS gensec_fake_gssapi_krb5_client_start(struct gensec_security *gensec_security)
 337 {
 338         NTSTATUS nt_status = gensec_krb5_client_start(gensec_security);
 339
 340         if (NT_STATUS_IS_OK(nt_status)) {
 341                 struct gensec_krb5_state *gensec_krb5_state;
 342                 gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
 343                 gensec_krb5_state->gssapi = true;
 344         }
 345         return nt_status;
 346 }
 347
 348 /**
 349  * Check if the packet is one for this mechansim
 350  *
 351  * @param gensec_security GENSEC state
 352  * @param in The request, as a DATA_BLOB
 353  * @return Error, INVALID_PARAMETER if it's not a packet for us
 354  *                or NT_STATUS_OK if the packet is ok.
 355  */
 356
 357 static NTSTATUS gensec_fake_gssapi_krb5_magic(struct gensec_security *gensec_security,
 358                                   const DATA_BLOB *in)
 359 {
 360         if (gensec_gssapi_check_oid(in, GENSEC_OID_KERBEROS5)) {
 361                 return NT_STATUS_OK;
 362         } else {
 363                 return NT_STATUS_INVALID_PARAMETER;
 364         }
 365 }
 366
 367
 368 /**
 369  * Next state function for the Krb5 GENSEC mechanism
 370  *
 371  * @param gensec_krb5_state KRB5 State
 372  * @param out_mem_ctx The TALLOC_CTX for *out to be allocated on
 373  * @param in The request, as a DATA_BLOB
 374  * @param out The reply, as an talloc()ed DATA_BLOB, on *out_mem_ctx
 375  * @return Error, MORE_PROCESSING_REQUIRED if a reply is sent,
 376  *                or NT_STATUS_OK if the user is authenticated.
 377  */
 378
 379 static NTSTATUS gensec_krb5_update(struct gensec_security *gensec_security,
 380                                    TALLOC_CTX *out_mem_ctx,
 381                                    const DATA_BLOB in, DATA_BLOB *out)
 382 {
 383         struct gensec_krb5_state *gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
 384         krb5_error_code ret = 0;
 385         NTSTATUS nt_status;
 386
 387         switch (gensec_krb5_state->state_position) {
 388         case GENSEC_KRB5_CLIENT_START:
 389         {
 390                 DATA_BLOB unwrapped_out;
 391
 392                 if (gensec_krb5_state->gssapi) {
 393                         unwrapped_out = data_blob_talloc(out_mem_ctx, gensec_krb5_state->enc_ticket.data, gensec_krb5_state->enc_ticket.length);
 394
 395                         /* wrap that up in a nice GSS-API wrapping */
 396                         *out = gensec_gssapi_gen_krb5_wrap(out_mem_ctx, &unwrapped_out, TOK_ID_KRB_AP_REQ);
 397                 } else {
 398                         *out = data_blob_talloc(out_mem_ctx, gensec_krb5_state->enc_ticket.data, gensec_krb5_state->enc_ticket.length);
 399                 }
 400                 if (gensec_krb5_state->ap_req_options & AP_OPTS_MUTUAL_REQUIRED) {
 401                         gensec_krb5_state->state_position = GENSEC_KRB5_CLIENT_MUTUAL_AUTH;
 402                         nt_status = NT_STATUS_MORE_PROCESSING_REQUIRED;
 403                 } else {
 404                         gensec_krb5_state->state_position = GENSEC_KRB5_DONE;
 405                         nt_status = NT_STATUS_OK;
 406                 }
 407                 return nt_status;
 408         }
 409
 410         case GENSEC_KRB5_CLIENT_MUTUAL_AUTH:
 411         {
 412                 DATA_BLOB unwrapped_in;
 413                 krb5_data inbuf;
 414                 krb5_ap_rep_enc_part *repl = NULL;
 415                 uint8_t tok_id[2];
 416
 417                 if (gensec_krb5_state->gssapi) {
 418                         if (!gensec_gssapi_parse_krb5_wrap(out_mem_ctx, &in, &unwrapped_in, tok_id)) {
 419                                 DEBUG(1,("gensec_gssapi_parse_krb5_wrap(mutual authentication) failed to parse\n"));
 420                                 dump_data_pw("Mutual authentication message:\n", in.data, in.length);
 421                                 return NT_STATUS_INVALID_PARAMETER;
 422                         }
 423                 } else {
 424                         unwrapped_in = in;
 425                 }
 426                 /* TODO: check the tok_id */
 427
 428                 inbuf.data = unwrapped_in.data;
 429                 inbuf.length = unwrapped_in.length;
 430                 ret = krb5_rd_rep(gensec_krb5_state->smb_krb5_context->krb5_context,
 431                                   gensec_krb5_state->auth_context,
 432                                   &inbuf, &repl);
 433                 if (ret) {
 434                         DEBUG(1,("krb5_rd_rep (mutual authentication) failed (%s)\n",
 435                                  smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context, ret, out_mem_ctx)));
 436                         dump_data_pw("Mutual authentication message:\n", (uint8_t *)inbuf.data, inbuf.length);
 437                         nt_status = NT_STATUS_ACCESS_DENIED;
 438                 } else {
 439                         *out = data_blob(NULL, 0);
 440                         nt_status = NT_STATUS_OK;
 441                         gensec_krb5_state->state_position = GENSEC_KRB5_DONE;
 442                 }
 443                 if (repl) {
 444                         krb5_free_ap_rep_enc_part(gensec_krb5_state->smb_krb5_context->krb5_context, repl);
 445                 }
 446                 return nt_status;
 447         }
 448
 449         case GENSEC_KRB5_SERVER_START:
 450         {
 451                 DATA_BLOB unwrapped_in;
 452                 DATA_BLOB unwrapped_out = data_blob(NULL, 0);
 453                 krb5_data inbuf, outbuf;
 454                 uint8_t tok_id[2];
 455                 struct keytab_container *keytab;
 456                 krb5_principal server_in_keytab;
 457
 458                 if (!in.data) {
 459                         return NT_STATUS_INVALID_PARAMETER;
 460                 }
 461
 462                 /* Grab the keytab, however generated */
 463                 ret = cli_credentials_get_keytab(gensec_get_credentials(gensec_security),
 464                                                  gensec_security->event_ctx,
 465                                                  gensec_security->settings->lp_ctx, &keytab);
 466                 if (ret) {
 467                         return NT_STATUS_CANT_ACCESS_DOMAIN_INFO;
 468                 }
 469
 470                 /* This ensures we lookup the correct entry in that keytab */
 471                 ret = principal_from_credentials(out_mem_ctx, gensec_get_credentials(gensec_security),
 472                                                  gensec_krb5_state->smb_krb5_context,
 473                                                  &server_in_keytab);
 474
 475                 if (ret) {
 476                         return NT_STATUS_CANT_ACCESS_DOMAIN_INFO;
 477                 }
 478
 479                 /* Parse the GSSAPI wrapping, if it's there... (win2k3 allows it to be omited) */
 480                 if (gensec_krb5_state->gssapi
 481                     && gensec_gssapi_parse_krb5_wrap(out_mem_ctx, &in, &unwrapped_in, tok_id)) {
 482                         inbuf.data = unwrapped_in.data;
 483                         inbuf.length = unwrapped_in.length;
 484                 } else {
 485                         inbuf.data = in.data;
 486                         inbuf.length = in.length;
 487                 }
 488
 489                 ret = smb_rd_req_return_stuff(gensec_krb5_state->smb_krb5_context->krb5_context,
 490                                               &gensec_krb5_state->auth_context,
 491                                               &inbuf, keytab->keytab, server_in_keytab,
 492                                               &outbuf,
 493                                               &gensec_krb5_state->ticket,
 494                                               &gensec_krb5_state->keyblock);
 495
 496                 if (ret) {
 497                         return NT_STATUS_LOGON_FAILURE;
 498                 }
 499                 unwrapped_out.data = (uint8_t *)outbuf.data;
 500                 unwrapped_out.length = outbuf.length;
 501                 gensec_krb5_state->state_position = GENSEC_KRB5_DONE;
 502                 /* wrap that up in a nice GSS-API wrapping */
 503                 if (gensec_krb5_state->gssapi) {
 504                         *out = gensec_gssapi_gen_krb5_wrap(out_mem_ctx, &unwrapped_out, TOK_ID_KRB_AP_REP);
 505                 } else {
 506                         *out = data_blob_talloc(out_mem_ctx, outbuf.data, outbuf.length);
 507                 }
 508                 krb5_data_free(&outbuf);
 509                 return NT_STATUS_OK;
 510         }
 511
 512         case GENSEC_KRB5_DONE:
 513         default:
 514                 /* Asking too many times... */
 515                 return NT_STATUS_INVALID_PARAMETER;
 516         }
 517 }
 518
 519 static NTSTATUS gensec_krb5_session_key(struct gensec_security *gensec_security,
 520                                         DATA_BLOB *session_key)
 521 {
 522         struct gensec_krb5_state *gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
 523         krb5_context context = gensec_krb5_state->smb_krb5_context->krb5_context;
 524         krb5_auth_context auth_context = gensec_krb5_state->auth_context;
 525         krb5_keyblock *skey;
 526         krb5_error_code err = -1;
 527
 528         if (gensec_krb5_state->state_position != GENSEC_KRB5_DONE) {
 529                 return NT_STATUS_NO_USER_SESSION_KEY;
 530         }
 531
 532         if (gensec_krb5_state->session_key.data) {
 533                 *session_key = gensec_krb5_state->session_key;
 534                 return NT_STATUS_OK;
 535         }
 536
 537         switch (gensec_security->gensec_role) {
 538         case GENSEC_CLIENT:
 539                 err = krb5_auth_con_getlocalsubkey(context, auth_context, &skey);
 540                 break;
 541         case GENSEC_SERVER:
 542                 err = krb5_auth_con_getremotesubkey(context, auth_context, &skey);
 543                 break;
 544         }
 545         if (err == 0 && skey != NULL) {
 546                 DEBUG(10, ("Got KRB5 session key of length %d\n",
 547                            (int)KRB5_KEY_LENGTH(skey)));
 548                 gensec_krb5_state->session_key = data_blob_talloc(gensec_krb5_state,
 549                                                 KRB5_KEY_DATA(skey), KRB5_KEY_LENGTH(skey));
 550                 *session_key = gensec_krb5_state->session_key;
 551                 dump_data_pw("KRB5 Session Key:\n", session_key->data, session_key->length);
 552
 553                 krb5_free_keyblock(context, skey);
 554                 return NT_STATUS_OK;
 555         } else {
 556                 DEBUG(10, ("KRB5 error getting session key %d\n", err));
 557                 return NT_STATUS_NO_USER_SESSION_KEY;
 558         }
 559 }
 560
 561 static NTSTATUS gensec_krb5_session_info(struct gensec_security *gensec_security,
 562                                          struct auth_session_info **_session_info)
 563 {
 564         NTSTATUS nt_status = NT_STATUS_UNSUCCESSFUL;
 565         struct gensec_krb5_state *gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
 566         krb5_context context = gensec_krb5_state->smb_krb5_context->krb5_context;
 567         struct auth_serversupplied_info *server_info = NULL;
 568         struct auth_session_info *session_info = NULL;
 569         struct PAC_LOGON_INFO *logon_info;
 570
 571         krb5_principal client_principal;
 572         char *principal_string;
 573
 574         DATA_BLOB pac;
 575         krb5_data pac_data;
 576
 577         krb5_error_code ret;
 578
 579         TALLOC_CTX *mem_ctx = talloc_new(gensec_security);
 580         if (!mem_ctx) {
 581                 return NT_STATUS_NO_MEMORY;
 582         }
 583
 584         ret = krb5_ticket_get_client(context, gensec_krb5_state->ticket, &client_principal);
 585         if (ret) {
 586                 DEBUG(5, ("krb5_ticket_get_client failed to get cleint principal: %s\n",
 587                           smb_get_krb5_error_message(context,
 588                                                      ret, mem_ctx)));
 589                 talloc_free(mem_ctx);
 590                 return NT_STATUS_NO_MEMORY;
 591         }
 592
 593         ret = krb5_unparse_name(gensec_krb5_state->smb_krb5_context->krb5_context,
 594                                 client_principal, &principal_string);
 595         if (ret) {
 596                 DEBUG(1, ("Unable to parse client principal: %s\n",
 597                           smb_get_krb5_error_message(context,
 598                                                      ret, mem_ctx)));
 599                 talloc_free(mem_ctx);
 600                 return NT_STATUS_NO_MEMORY;
 601         }
 602
 603         ret = krb5_ticket_get_authorization_data_type(context, gensec_krb5_state->ticket,
 604                                                       KRB5_AUTHDATA_WIN2K_PAC,
 605                                                       &pac_data);
 606
 607         if (ret && gensec_setting_bool(gensec_security->settings, "gensec", "require_pac", false)) {
 608                 DEBUG(1, ("Unable to find PAC in ticket from %s, failing to allow access: %s \n",
 609                           principal_string,
 610                           smb_get_krb5_error_message(context,
 611                                                      ret, mem_ctx)));
 612                 krb5_free_principal(context, client_principal);
 613                 free(principal_string);
 614                 return NT_STATUS_ACCESS_DENIED;
 615         } else if (ret) {
 616                 /* NO pac */
 617                 DEBUG(5, ("krb5_ticket_get_authorization_data_type failed to find PAC: %s\n",
 618                           smb_get_krb5_error_message(context,
 619                                                      ret, mem_ctx)));
 620                 if (gensec_security->auth_context &&
 621                     !gensec_setting_bool(gensec_security->settings, "gensec", "require_pac", false)) {
 622                         DEBUG(1, ("Unable to find PAC for %s, resorting to local user lookup: %s",
 623                                   principal_string, smb_get_krb5_error_message(context,
 624                                                      ret, mem_ctx)));
 625                         nt_status = gensec_security->auth_context->get_server_info_principal(mem_ctx,
 626                                                                                              gensec_security->auth_context,
 627                                                                                              principal_string,
 628                                                                                              &server_info);
 629                         if (!NT_STATUS_IS_OK(nt_status)) {
 630                                 talloc_free(mem_ctx);
 631                                 return nt_status;
 632                         }
 633                 } else {
 634                         DEBUG(1, ("Unable to find PAC in ticket from %s, failing to allow access\n",
 635                                   principal_string));
 636                         return NT_STATUS_ACCESS_DENIED;
 637                 }
 638
 639                 krb5_free_principal(context, client_principal);
 640                 free(principal_string);
 641
 642                 if (!NT_STATUS_IS_OK(nt_status)) {
 643                         talloc_free(mem_ctx);
 644                         return nt_status;
 645                 }
 646         } else {
 647                 /* Found pac */
 648                 union netr_Validation validation;
 649                 free(principal_string);
 650
 651                 pac = data_blob_talloc(mem_ctx, pac_data.data, pac_data.length);
 652                 if (!pac.data) {
 653                         krb5_free_principal(context, client_principal);
 654                         talloc_free(mem_ctx);
 655                         return NT_STATUS_NO_MEMORY;
 656                 }
 657
 658                 /* decode and verify the pac */
 659                 nt_status = kerberos_pac_logon_info(gensec_krb5_state,
 660                                                     gensec_security->settings->iconv_convenience,
 661                                                     &logon_info, pac,
 662                                                     gensec_krb5_state->smb_krb5_context->krb5_context,
 663                                                     NULL, gensec_krb5_state->keyblock,
 664                                                     client_principal,
 665                                                     gensec_krb5_state->ticket->ticket.authtime, NULL);
 666                 krb5_free_principal(context, client_principal);
 667
 668                 if (!NT_STATUS_IS_OK(nt_status)) {
 669                         talloc_free(mem_ctx);
 670                         return nt_status;
 671                 }
 672
 673                 validation.sam3 = &logon_info->info3;
 674                 nt_status = make_server_info_netlogon_validation(mem_ctx,
 675                                                                  NULL,
 676                                                                  3, &validation,
 677                                                                  &server_info);
 678                 if (!NT_STATUS_IS_OK(nt_status)) {
 679                         talloc_free(mem_ctx);
 680                         return nt_status;
 681                 }
 682         }
 683
 684         /* references the server_info into the session_info */
 685         nt_status = auth_generate_session_info(mem_ctx, gensec_security->event_ctx, gensec_security->settings->lp_ctx, server_info, &session_info);
 686
 687         if (!NT_STATUS_IS_OK(nt_status)) {
 688                 talloc_free(mem_ctx);
 689                 return nt_status;
 690         }
 691
 692         nt_status = gensec_krb5_session_key(gensec_security, &session_info->session_key);
 693
 694         if (!NT_STATUS_IS_OK(nt_status)) {
 695                 talloc_free(mem_ctx);
 696                 return nt_status;
 697         }
 698
 699         *_session_info = session_info;
 700
 701         talloc_steal(gensec_krb5_state, session_info);
 702         talloc_free(mem_ctx);
 703         return NT_STATUS_OK;
 704 }
 705
 706 static NTSTATUS gensec_krb5_wrap(struct gensec_security *gensec_security,
 707                                    TALLOC_CTX *mem_ctx,
 708                                    const DATA_BLOB *in,
 709                                    DATA_BLOB *out)
 710 {
 711         struct gensec_krb5_state *gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
 712         krb5_context context = gensec_krb5_state->smb_krb5_context->krb5_context;
 713         krb5_auth_context auth_context = gensec_krb5_state->auth_context;
 714         krb5_error_code ret;
 715         krb5_data input, output;
 716         input.length = in->length;
 717         input.data = in->data;
 718
 719         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
 720                 ret = krb5_mk_priv(context, auth_context, &input, &output, NULL);
 721                 if (ret) {
 722                         DEBUG(1, ("krb5_mk_priv failed: %s\n",
 723                                   smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context,
 724                                                              ret, mem_ctx)));
 725                         return NT_STATUS_ACCESS_DENIED;
 726                 }
 727                 *out = data_blob_talloc(mem_ctx, output.data, output.length);
 728
 729                 krb5_data_free(&output);
 730         } else {
 731                 return NT_STATUS_ACCESS_DENIED;
 732         }
 733         return NT_STATUS_OK;
 734 }
 735
 736 static NTSTATUS gensec_krb5_unwrap(struct gensec_security *gensec_security,
 737                                      TALLOC_CTX *mem_ctx,
 738                                      const DATA_BLOB *in,
 739                                      DATA_BLOB *out)
 740 {
 741         struct gensec_krb5_state *gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
 742         krb5_context context = gensec_krb5_state->smb_krb5_context->krb5_context;
 743         krb5_auth_context auth_context = gensec_krb5_state->auth_context;
 744         krb5_error_code ret;
 745         krb5_data input, output;
 746         krb5_replay_data replay;
 747         input.length = in->length;
 748         input.data = in->data;
 749
 750         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
 751                 ret = krb5_rd_priv(context, auth_context, &input, &output, &replay);
 752                 if (ret) {
 753                         DEBUG(1, ("krb5_rd_priv failed: %s\n",
 754                                   smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context,
 755                                                              ret, mem_ctx)));
 756                         return NT_STATUS_ACCESS_DENIED;
 757                 }
 758                 *out = data_blob_talloc(mem_ctx, output.data, output.length);
 759
 760                 krb5_data_free(&output);
 761         } else {
 762                 return NT_STATUS_ACCESS_DENIED;
 763         }
 764         return NT_STATUS_OK;
 765 }
 766
 767 static bool gensec_krb5_have_feature(struct gensec_security *gensec_security,
 768                                      uint32_t feature)
 769 {
 770         struct gensec_krb5_state *gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
 771         if (feature & GENSEC_FEATURE_SESSION_KEY) {
 772                 return true;
 773         }
 774         if (!gensec_krb5_state->gssapi &&
 775             (feature & GENSEC_FEATURE_SEAL)) {
 776                 return true;
 777         }
 778
 779         return false;
 780 }
 781
 782 static const char *gensec_krb5_oids[] = {
 783         GENSEC_OID_KERBEROS5,
 784         GENSEC_OID_KERBEROS5_OLD,
 785         NULL
 786 };
 787
 788 static const struct gensec_security_ops gensec_fake_gssapi_krb5_security_ops = {
 789         .name           = "fake_gssapi_krb5",
 790         .auth_type      = DCERPC_AUTH_TYPE_KRB5,
 791         .oid            = gensec_krb5_oids,
 792         .client_start   = gensec_fake_gssapi_krb5_client_start,
 793         .server_start   = gensec_fake_gssapi_krb5_server_start,
 794         .update         = gensec_krb5_update,
 795         .magic          = gensec_fake_gssapi_krb5_magic,
 796         .session_key    = gensec_krb5_session_key,
 797         .session_info   = gensec_krb5_session_info,
 798         .have_feature   = gensec_krb5_have_feature,
 799         .enabled        = false,
 800         .kerberos       = true,
 801         .priority       = GENSEC_KRB5
 802 };
 803
 804 static const struct gensec_security_ops gensec_krb5_security_ops = {
 805         .name           = "krb5",
 806         .client_start   = gensec_krb5_client_start,
 807         .server_start   = gensec_krb5_server_start,
 808         .update         = gensec_krb5_update,
 809         .session_key    = gensec_krb5_session_key,
 810         .session_info   = gensec_krb5_session_info,
 811         .have_feature   = gensec_krb5_have_feature,
 812         .wrap           = gensec_krb5_wrap,
 813         .unwrap         = gensec_krb5_unwrap,
 814         .enabled        = true,
 815         .kerberos       = true,
 816         .priority       = GENSEC_KRB5
 817 };
 818
 819 _PUBLIC_ NTSTATUS gensec_krb5_init(void)
 820 {
 821         NTSTATUS ret;
 822
 823         ret = gensec_register(&gensec_krb5_security_ops);
 824         if (!NT_STATUS_IS_OK(ret)) {
 825                 DEBUG(0,("Failed to register '%s' gensec backend!\n",
 826                         gensec_krb5_security_ops.name));
 827                 return ret;
 828         }
 829
 830         ret = gensec_register(&gensec_fake_gssapi_krb5_security_ops);
 831         if (!NT_STATUS_IS_OK(ret)) {
 832                 DEBUG(0,("Failed to register '%s' gensec backend!\n",
 833                         gensec_krb5_security_ops.name));
 834                 return ret;
 835         }
 836
 837         return ret;
 838 }