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, bool gssapi)
  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 = gssapi;
 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_common_server_start(struct gensec_security *gensec_security, bool gssapi)
 191 {
 192         NTSTATUS nt_status;
 193         struct gensec_krb5_state *gensec_krb5_state;
 194
 195         nt_status = gensec_krb5_start(gensec_security, gssapi);
 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_krb5_server_start(struct gensec_security *gensec_security)
 207 {
 208         return gensec_krb5_common_server_start(gensec_security, false);
 209 }
 210
 211 static NTSTATUS gensec_fake_gssapi_krb5_server_start(struct gensec_security *gensec_security)
 212 {
 213         return gensec_krb5_common_server_start(gensec_security, true);
 214 }
 215
 216 static NTSTATUS gensec_krb5_common_client_start(struct gensec_security *gensec_security, bool gssapi)
 217 {
 218         struct gensec_krb5_state *gensec_krb5_state;
 219         krb5_error_code ret;
 220         NTSTATUS nt_status;
 221         struct ccache_container *ccache_container;
 222         const char *hostname;
 223
 224         const char *principal;
 225         krb5_data in_data;
 226
 227         hostname = gensec_get_target_hostname(gensec_security);
 228         if (!hostname) {
 229                 DEBUG(1, ("Could not determine hostname for target computer, cannot use kerberos\n"));
 230                 return NT_STATUS_INVALID_PARAMETER;
 231         }
 232         if (is_ipaddress(hostname)) {
 233                 DEBUG(2, ("Cannot do krb5 to an IP address"));
 234                 return NT_STATUS_INVALID_PARAMETER;
 235         }
 236         if (strcmp(hostname, "localhost") == 0) {
 237                 DEBUG(2, ("krb5 to 'localhost' does not make sense"));
 238                 return NT_STATUS_INVALID_PARAMETER;
 239         }
 240
 241         nt_status = gensec_krb5_start(gensec_security, gssapi);
 242         if (!NT_STATUS_IS_OK(nt_status)) {
 243                 return nt_status;
 244         }
 245
 246         gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
 247         gensec_krb5_state->state_position = GENSEC_KRB5_CLIENT_START;
 248         gensec_krb5_state->ap_req_options = AP_OPTS_USE_SUBKEY;
 249
 250         if (gensec_krb5_state->gssapi) {
 251                 /* The Fake GSSAPI modal emulates Samba3, which does not do mutual authentication */
 252                 if (gensec_setting_bool(gensec_security->settings, "gensec_fake_gssapi_krb5", "mutual", false)) {
 253                         gensec_krb5_state->ap_req_options |= AP_OPTS_MUTUAL_REQUIRED;
 254                 }
 255         } else {
 256                 /* The wrapping for KPASSWD (a user of the raw KRB5 API) should be mutually authenticated */
 257                 if (gensec_setting_bool(gensec_security->settings, "gensec_krb5", "mutual", true)) {
 258                         gensec_krb5_state->ap_req_options |= AP_OPTS_MUTUAL_REQUIRED;
 259                 }
 260         }
 261
 262         principal = gensec_get_target_principal(gensec_security);
 263
 264         ret = cli_credentials_get_ccache(gensec_get_credentials(gensec_security),
 265                                          gensec_security->event_ctx,
 266                                          gensec_security->settings->lp_ctx, &ccache_container);
 267         switch (ret) {
 268         case 0:
 269                 break;
 270         case KRB5KDC_ERR_PREAUTH_FAILED:
 271                 return NT_STATUS_LOGON_FAILURE;
 272         case KRB5_KDC_UNREACH:
 273                 DEBUG(3, ("Cannot reach a KDC we require to contact %s\n", principal));
 274                 return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
 275         default:
 276                 DEBUG(1, ("gensec_krb5_start: Aquiring initiator credentials failed: %s\n", error_message(ret)));
 277                 return NT_STATUS_UNSUCCESSFUL;
 278         }
 279         in_data.length = 0;
 280
 281         if (principal && lp_client_use_spnego_principal(gensec_security->settings->lp_ctx)) {
 282                 krb5_principal target_principal;
 283                 ret = krb5_parse_name(gensec_krb5_state->smb_krb5_context->krb5_context, principal,
 284                                       &target_principal);
 285                 if (ret == 0) {
 286                         ret = krb5_mk_req_exact(gensec_krb5_state->smb_krb5_context->krb5_context,
 287                                                 &gensec_krb5_state->auth_context,
 288                                                 gensec_krb5_state->ap_req_options,
 289                                                 target_principal,
 290                                                 &in_data, ccache_container->ccache,
 291                                                 &gensec_krb5_state->enc_ticket);
 292                         krb5_free_principal(gensec_krb5_state->smb_krb5_context->krb5_context,
 293                                             target_principal);
 294                 }
 295         } else {
 296                 ret = krb5_mk_req(gensec_krb5_state->smb_krb5_context->krb5_context,
 297                                   &gensec_krb5_state->auth_context,
 298                                   gensec_krb5_state->ap_req_options,
 299                                   gensec_get_target_service(gensec_security),
 300                                   hostname,
 301                                   &in_data, ccache_container->ccache,
 302                                   &gensec_krb5_state->enc_ticket);
 303         }
 304         switch (ret) {
 305         case 0:
 306                 return NT_STATUS_OK;
 307         case KRB5KDC_ERR_S_PRINCIPAL_UNKNOWN:
 308                 DEBUG(3, ("Server [%s] is not registered with our KDC: %s\n",
 309                           hostname, smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context, ret, gensec_krb5_state)));
 310                 return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
 311         case KRB5_KDC_UNREACH:
 312                 DEBUG(3, ("Cannot reach a KDC we require to contact host [%s]: %s\n",
 313                           hostname, smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context, ret, gensec_krb5_state)));
 314                 return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
 315         case KRB5KDC_ERR_PREAUTH_FAILED:
 316         case KRB5KRB_AP_ERR_TKT_EXPIRED:
 317         case KRB5_CC_END:
 318                 /* Too much clock skew - we will need to kinit to re-skew the clock */
 319         case KRB5KRB_AP_ERR_SKEW:
 320         case KRB5_KDCREP_SKEW:
 321         {
 322                 DEBUG(3, ("kerberos (mk_req) failed: %s\n",
 323                           smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context, ret, gensec_krb5_state)));
 324                 /*fall through*/
 325         }
 326
 327         /* just don't print a message for these really ordinary messages */
 328         case KRB5_FCC_NOFILE:
 329         case KRB5_CC_NOTFOUND:
 330         case ENOENT:
 331
 332                 return NT_STATUS_UNSUCCESSFUL;
 333                 break;
 334
 335         default:
 336                 DEBUG(0, ("kerberos: %s\n",
 337                           smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context, ret, gensec_krb5_state)));
 338                 return NT_STATUS_UNSUCCESSFUL;
 339         }
 340 }
 341
 342 static NTSTATUS gensec_krb5_client_start(struct gensec_security *gensec_security)
 343 {
 344         return gensec_krb5_common_client_start(gensec_security, false);
 345 }
 346
 347 static NTSTATUS gensec_fake_gssapi_krb5_client_start(struct gensec_security *gensec_security)
 348 {
 349         return gensec_krb5_common_client_start(gensec_security, true);
 350 }
 351
 352 /**
 353  * Check if the packet is one for this mechansim
 354  *
 355  * @param gensec_security GENSEC state
 356  * @param in The request, as a DATA_BLOB
 357  * @return Error, INVALID_PARAMETER if it's not a packet for us
 358  *                or NT_STATUS_OK if the packet is ok.
 359  */
 360
 361 static NTSTATUS gensec_fake_gssapi_krb5_magic(struct gensec_security *gensec_security,
 362                                   const DATA_BLOB *in)
 363 {
 364         if (gensec_gssapi_check_oid(in, GENSEC_OID_KERBEROS5)) {
 365                 return NT_STATUS_OK;
 366         } else {
 367                 return NT_STATUS_INVALID_PARAMETER;
 368         }
 369 }
 370
 371
 372 /**
 373  * Next state function for the Krb5 GENSEC mechanism
 374  *
 375  * @param gensec_krb5_state KRB5 State
 376  * @param out_mem_ctx The TALLOC_CTX for *out to be allocated on
 377  * @param in The request, as a DATA_BLOB
 378  * @param out The reply, as an talloc()ed DATA_BLOB, on *out_mem_ctx
 379  * @return Error, MORE_PROCESSING_REQUIRED if a reply is sent,
 380  *                or NT_STATUS_OK if the user is authenticated.
 381  */
 382
 383 static NTSTATUS gensec_krb5_update(struct gensec_security *gensec_security,
 384                                    TALLOC_CTX *out_mem_ctx,
 385                                    const DATA_BLOB in, DATA_BLOB *out)
 386 {
 387         struct gensec_krb5_state *gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
 388         krb5_error_code ret = 0;
 389         NTSTATUS nt_status;
 390
 391         switch (gensec_krb5_state->state_position) {
 392         case GENSEC_KRB5_CLIENT_START:
 393         {
 394                 DATA_BLOB unwrapped_out;
 395
 396                 if (gensec_krb5_state->gssapi) {
 397                         unwrapped_out = data_blob_talloc(out_mem_ctx, gensec_krb5_state->enc_ticket.data, gensec_krb5_state->enc_ticket.length);
 398
 399                         /* wrap that up in a nice GSS-API wrapping */
 400                         *out = gensec_gssapi_gen_krb5_wrap(out_mem_ctx, &unwrapped_out, TOK_ID_KRB_AP_REQ);
 401                 } else {
 402                         *out = data_blob_talloc(out_mem_ctx, gensec_krb5_state->enc_ticket.data, gensec_krb5_state->enc_ticket.length);
 403                 }
 404                 if (gensec_krb5_state->ap_req_options & AP_OPTS_MUTUAL_REQUIRED) {
 405                         gensec_krb5_state->state_position = GENSEC_KRB5_CLIENT_MUTUAL_AUTH;
 406                         nt_status = NT_STATUS_MORE_PROCESSING_REQUIRED;
 407                 } else {
 408                         gensec_krb5_state->state_position = GENSEC_KRB5_DONE;
 409                         nt_status = NT_STATUS_OK;
 410                 }
 411                 return nt_status;
 412         }
 413
 414         case GENSEC_KRB5_CLIENT_MUTUAL_AUTH:
 415         {
 416                 DATA_BLOB unwrapped_in;
 417                 krb5_data inbuf;
 418                 krb5_ap_rep_enc_part *repl = NULL;
 419                 uint8_t tok_id[2];
 420
 421                 if (gensec_krb5_state->gssapi) {
 422                         if (!gensec_gssapi_parse_krb5_wrap(out_mem_ctx, &in, &unwrapped_in, tok_id)) {
 423                                 DEBUG(1,("gensec_gssapi_parse_krb5_wrap(mutual authentication) failed to parse\n"));
 424                                 dump_data_pw("Mutual authentication message:\n", in.data, in.length);
 425                                 return NT_STATUS_INVALID_PARAMETER;
 426                         }
 427                 } else {
 428                         unwrapped_in = in;
 429                 }
 430                 /* TODO: check the tok_id */
 431
 432                 inbuf.data = unwrapped_in.data;
 433                 inbuf.length = unwrapped_in.length;
 434                 ret = krb5_rd_rep(gensec_krb5_state->smb_krb5_context->krb5_context,
 435                                   gensec_krb5_state->auth_context,
 436                                   &inbuf, &repl);
 437                 if (ret) {
 438                         DEBUG(1,("krb5_rd_rep (mutual authentication) failed (%s)\n",
 439                                  smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context, ret, out_mem_ctx)));
 440                         dump_data_pw("Mutual authentication message:\n", (uint8_t *)inbuf.data, inbuf.length);
 441                         nt_status = NT_STATUS_ACCESS_DENIED;
 442                 } else {
 443                         *out = data_blob(NULL, 0);
 444                         nt_status = NT_STATUS_OK;
 445                         gensec_krb5_state->state_position = GENSEC_KRB5_DONE;
 446                 }
 447                 if (repl) {
 448                         krb5_free_ap_rep_enc_part(gensec_krb5_state->smb_krb5_context->krb5_context, repl);
 449                 }
 450                 return nt_status;
 451         }
 452
 453         case GENSEC_KRB5_SERVER_START:
 454         {
 455                 DATA_BLOB unwrapped_in;
 456                 DATA_BLOB unwrapped_out = data_blob(NULL, 0);
 457                 krb5_data inbuf, outbuf;
 458                 uint8_t tok_id[2];
 459                 struct keytab_container *keytab;
 460                 krb5_principal server_in_keytab;
 461
 462                 if (!in.data) {
 463                         return NT_STATUS_INVALID_PARAMETER;
 464                 }
 465
 466                 /* Grab the keytab, however generated */
 467                 ret = cli_credentials_get_keytab(gensec_get_credentials(gensec_security),
 468                                                  gensec_security->event_ctx,
 469                                                  gensec_security->settings->lp_ctx, &keytab);
 470                 if (ret) {
 471                         return NT_STATUS_CANT_ACCESS_DOMAIN_INFO;
 472                 }
 473
 474                 /* This ensures we lookup the correct entry in that keytab */
 475                 ret = principal_from_credentials(out_mem_ctx, gensec_get_credentials(gensec_security),
 476                                                  gensec_krb5_state->smb_krb5_context,
 477                                                  &server_in_keytab);
 478
 479                 if (ret) {
 480                         return NT_STATUS_CANT_ACCESS_DOMAIN_INFO;
 481                 }
 482
 483                 /* Parse the GSSAPI wrapping, if it's there... (win2k3 allows it to be omited) */
 484                 if (gensec_krb5_state->gssapi
 485                     && gensec_gssapi_parse_krb5_wrap(out_mem_ctx, &in, &unwrapped_in, tok_id)) {
 486                         inbuf.data = unwrapped_in.data;
 487                         inbuf.length = unwrapped_in.length;
 488                 } else {
 489                         inbuf.data = in.data;
 490                         inbuf.length = in.length;
 491                 }
 492
 493                 ret = smb_rd_req_return_stuff(gensec_krb5_state->smb_krb5_context->krb5_context,
 494                                               &gensec_krb5_state->auth_context,
 495                                               &inbuf, keytab->keytab, server_in_keytab,
 496                                               &outbuf,
 497                                               &gensec_krb5_state->ticket,
 498                                               &gensec_krb5_state->keyblock);
 499
 500                 if (ret) {
 501                         return NT_STATUS_LOGON_FAILURE;
 502                 }
 503                 unwrapped_out.data = (uint8_t *)outbuf.data;
 504                 unwrapped_out.length = outbuf.length;
 505                 gensec_krb5_state->state_position = GENSEC_KRB5_DONE;
 506                 /* wrap that up in a nice GSS-API wrapping */
 507                 if (gensec_krb5_state->gssapi) {
 508                         *out = gensec_gssapi_gen_krb5_wrap(out_mem_ctx, &unwrapped_out, TOK_ID_KRB_AP_REP);
 509                 } else {
 510                         *out = data_blob_talloc(out_mem_ctx, outbuf.data, outbuf.length);
 511                 }
 512                 krb5_data_free(&outbuf);
 513                 return NT_STATUS_OK;
 514         }
 515
 516         case GENSEC_KRB5_DONE:
 517         default:
 518                 /* Asking too many times... */
 519                 return NT_STATUS_INVALID_PARAMETER;
 520         }
 521 }
 522
 523 static NTSTATUS gensec_krb5_session_key(struct gensec_security *gensec_security,
 524                                         DATA_BLOB *session_key)
 525 {
 526         struct gensec_krb5_state *gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
 527         krb5_context context = gensec_krb5_state->smb_krb5_context->krb5_context;
 528         krb5_auth_context auth_context = gensec_krb5_state->auth_context;
 529         krb5_keyblock *skey;
 530         krb5_error_code err = -1;
 531
 532         if (gensec_krb5_state->state_position != GENSEC_KRB5_DONE) {
 533                 return NT_STATUS_NO_USER_SESSION_KEY;
 534         }
 535
 536         if (gensec_krb5_state->session_key.data) {
 537                 *session_key = gensec_krb5_state->session_key;
 538                 return NT_STATUS_OK;
 539         }
 540
 541         switch (gensec_security->gensec_role) {
 542         case GENSEC_CLIENT:
 543                 err = krb5_auth_con_getlocalsubkey(context, auth_context, &skey);
 544                 break;
 545         case GENSEC_SERVER:
 546                 err = krb5_auth_con_getremotesubkey(context, auth_context, &skey);
 547                 break;
 548         }
 549         if (err == 0 && skey != NULL) {
 550                 DEBUG(10, ("Got KRB5 session key of length %d\n",
 551                            (int)KRB5_KEY_LENGTH(skey)));
 552                 gensec_krb5_state->session_key = data_blob_talloc(gensec_krb5_state,
 553                                                 KRB5_KEY_DATA(skey), KRB5_KEY_LENGTH(skey));
 554                 *session_key = gensec_krb5_state->session_key;
 555                 dump_data_pw("KRB5 Session Key:\n", session_key->data, session_key->length);
 556
 557                 krb5_free_keyblock(context, skey);
 558                 return NT_STATUS_OK;
 559         } else {
 560                 DEBUG(10, ("KRB5 error getting session key %d\n", err));
 561                 return NT_STATUS_NO_USER_SESSION_KEY;
 562         }
 563 }
 564
 565 static NTSTATUS gensec_krb5_session_info(struct gensec_security *gensec_security,
 566                                          struct auth_session_info **_session_info)
 567 {
 568         NTSTATUS nt_status = NT_STATUS_UNSUCCESSFUL;
 569         struct gensec_krb5_state *gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
 570         krb5_context context = gensec_krb5_state->smb_krb5_context->krb5_context;
 571         struct auth_serversupplied_info *server_info = NULL;
 572         struct auth_session_info *session_info = NULL;
 573         struct PAC_LOGON_INFO *logon_info;
 574
 575         krb5_principal client_principal;
 576         char *principal_string;
 577
 578         DATA_BLOB pac;
 579         krb5_data pac_data;
 580
 581         krb5_error_code ret;
 582
 583         TALLOC_CTX *mem_ctx = talloc_new(gensec_security);
 584         if (!mem_ctx) {
 585                 return NT_STATUS_NO_MEMORY;
 586         }
 587
 588         ret = krb5_ticket_get_client(context, gensec_krb5_state->ticket, &client_principal);
 589         if (ret) {
 590                 DEBUG(5, ("krb5_ticket_get_client failed to get cleint principal: %s\n",
 591                           smb_get_krb5_error_message(context,
 592                                                      ret, mem_ctx)));
 593                 talloc_free(mem_ctx);
 594                 return NT_STATUS_NO_MEMORY;
 595         }
 596
 597         ret = krb5_unparse_name(gensec_krb5_state->smb_krb5_context->krb5_context,
 598                                 client_principal, &principal_string);
 599         if (ret) {
 600                 DEBUG(1, ("Unable to parse client principal: %s\n",
 601                           smb_get_krb5_error_message(context,
 602                                                      ret, mem_ctx)));
 603                 talloc_free(mem_ctx);
 604                 return NT_STATUS_NO_MEMORY;
 605         }
 606
 607         ret = krb5_ticket_get_authorization_data_type(context, gensec_krb5_state->ticket,
 608                                                       KRB5_AUTHDATA_WIN2K_PAC,
 609                                                       &pac_data);
 610
 611         if (ret && gensec_setting_bool(gensec_security->settings, "gensec", "require_pac", false)) {
 612                 DEBUG(1, ("Unable to find PAC in ticket from %s, failing to allow access: %s \n",
 613                           principal_string,
 614                           smb_get_krb5_error_message(context,
 615                                                      ret, mem_ctx)));
 616                 krb5_free_principal(context, client_principal);
 617                 free(principal_string);
 618                 return NT_STATUS_ACCESS_DENIED;
 619         } else if (ret) {
 620                 /* NO pac */
 621                 DEBUG(5, ("krb5_ticket_get_authorization_data_type failed to find PAC: %s\n",
 622                           smb_get_krb5_error_message(context,
 623                                                      ret, mem_ctx)));
 624                 if (gensec_security->auth_context &&
 625                     !gensec_setting_bool(gensec_security->settings, "gensec", "require_pac", false)) {
 626                         DEBUG(1, ("Unable to find PAC for %s, resorting to local user lookup: %s",
 627                                   principal_string, smb_get_krb5_error_message(context,
 628                                                      ret, mem_ctx)));
 629                         nt_status = gensec_security->auth_context->get_server_info_principal(mem_ctx,
 630                                                                                              gensec_security->auth_context,
 631                                                                                              principal_string,
 632                                                                                              &server_info);
 633                         if (!NT_STATUS_IS_OK(nt_status)) {
 634                                 talloc_free(mem_ctx);
 635                                 return nt_status;
 636                         }
 637                 } else {
 638                         DEBUG(1, ("Unable to find PAC in ticket from %s, failing to allow access\n",
 639                                   principal_string));
 640                         return NT_STATUS_ACCESS_DENIED;
 641                 }
 642
 643                 krb5_free_principal(context, client_principal);
 644                 free(principal_string);
 645
 646                 if (!NT_STATUS_IS_OK(nt_status)) {
 647                         talloc_free(mem_ctx);
 648                         return nt_status;
 649                 }
 650         } else {
 651                 /* Found pac */
 652                 union netr_Validation validation;
 653                 free(principal_string);
 654
 655                 pac = data_blob_talloc(mem_ctx, pac_data.data, pac_data.length);
 656                 if (!pac.data) {
 657                         krb5_free_principal(context, client_principal);
 658                         talloc_free(mem_ctx);
 659                         return NT_STATUS_NO_MEMORY;
 660                 }
 661
 662                 /* decode and verify the pac */
 663                 nt_status = kerberos_pac_logon_info(gensec_krb5_state,
 664                                                     gensec_security->settings->iconv_convenience,
 665                                                     &logon_info, pac,
 666                                                     gensec_krb5_state->smb_krb5_context->krb5_context,
 667                                                     NULL, gensec_krb5_state->keyblock,
 668                                                     client_principal,
 669                                                     gensec_krb5_state->ticket->ticket.authtime, NULL);
 670                 krb5_free_principal(context, client_principal);
 671
 672                 if (!NT_STATUS_IS_OK(nt_status)) {
 673                         talloc_free(mem_ctx);
 674                         return nt_status;
 675                 }
 676
 677                 validation.sam3 = &logon_info->info3;
 678                 nt_status = make_server_info_netlogon_validation(mem_ctx,
 679                                                                  NULL,
 680                                                                  3, &validation,
 681                                                                  &server_info);
 682                 if (!NT_STATUS_IS_OK(nt_status)) {
 683                         talloc_free(mem_ctx);
 684                         return nt_status;
 685                 }
 686         }
 687
 688         /* references the server_info into the session_info */
 689         nt_status = auth_generate_session_info(mem_ctx, gensec_security->event_ctx, gensec_security->settings->lp_ctx, server_info, &session_info);
 690
 691         if (!NT_STATUS_IS_OK(nt_status)) {
 692                 talloc_free(mem_ctx);
 693                 return nt_status;
 694         }
 695
 696         nt_status = gensec_krb5_session_key(gensec_security, &session_info->session_key);
 697
 698         if (!NT_STATUS_IS_OK(nt_status)) {
 699                 talloc_free(mem_ctx);
 700                 return nt_status;
 701         }
 702
 703         *_session_info = session_info;
 704
 705         talloc_steal(gensec_krb5_state, session_info);
 706         talloc_free(mem_ctx);
 707         return NT_STATUS_OK;
 708 }
 709
 710 static NTSTATUS gensec_krb5_wrap(struct gensec_security *gensec_security,
 711                                    TALLOC_CTX *mem_ctx,
 712                                    const DATA_BLOB *in,
 713                                    DATA_BLOB *out)
 714 {
 715         struct gensec_krb5_state *gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
 716         krb5_context context = gensec_krb5_state->smb_krb5_context->krb5_context;
 717         krb5_auth_context auth_context = gensec_krb5_state->auth_context;
 718         krb5_error_code ret;
 719         krb5_data input, output;
 720         input.length = in->length;
 721         input.data = in->data;
 722
 723         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
 724                 ret = krb5_mk_priv(context, auth_context, &input, &output, NULL);
 725                 if (ret) {
 726                         DEBUG(1, ("krb5_mk_priv failed: %s\n",
 727                                   smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context,
 728                                                              ret, mem_ctx)));
 729                         return NT_STATUS_ACCESS_DENIED;
 730                 }
 731                 *out = data_blob_talloc(mem_ctx, output.data, output.length);
 732
 733                 krb5_data_free(&output);
 734         } else {
 735                 return NT_STATUS_ACCESS_DENIED;
 736         }
 737         return NT_STATUS_OK;
 738 }
 739
 740 static NTSTATUS gensec_krb5_unwrap(struct gensec_security *gensec_security,
 741                                      TALLOC_CTX *mem_ctx,
 742                                      const DATA_BLOB *in,
 743                                      DATA_BLOB *out)
 744 {
 745         struct gensec_krb5_state *gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
 746         krb5_context context = gensec_krb5_state->smb_krb5_context->krb5_context;
 747         krb5_auth_context auth_context = gensec_krb5_state->auth_context;
 748         krb5_error_code ret;
 749         krb5_data input, output;
 750         krb5_replay_data replay;
 751         input.length = in->length;
 752         input.data = in->data;
 753
 754         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
 755                 ret = krb5_rd_priv(context, auth_context, &input, &output, &replay);
 756                 if (ret) {
 757                         DEBUG(1, ("krb5_rd_priv failed: %s\n",
 758                                   smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context,
 759                                                              ret, mem_ctx)));
 760                         return NT_STATUS_ACCESS_DENIED;
 761                 }
 762                 *out = data_blob_talloc(mem_ctx, output.data, output.length);
 763
 764                 krb5_data_free(&output);
 765         } else {
 766                 return NT_STATUS_ACCESS_DENIED;
 767         }
 768         return NT_STATUS_OK;
 769 }
 770
 771 static bool gensec_krb5_have_feature(struct gensec_security *gensec_security,
 772                                      uint32_t feature)
 773 {
 774         struct gensec_krb5_state *gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
 775         if (feature & GENSEC_FEATURE_SESSION_KEY) {
 776                 return true;
 777         }
 778         if (!gensec_krb5_state->gssapi &&
 779             (feature & GENSEC_FEATURE_SEAL)) {
 780                 return true;
 781         }
 782
 783         return false;
 784 }
 785
 786 static const char *gensec_krb5_oids[] = {
 787         GENSEC_OID_KERBEROS5,
 788         GENSEC_OID_KERBEROS5_OLD,
 789         NULL
 790 };
 791
 792 static const struct gensec_security_ops gensec_fake_gssapi_krb5_security_ops = {
 793         .name           = "fake_gssapi_krb5",
 794         .auth_type      = DCERPC_AUTH_TYPE_KRB5,
 795         .oid            = gensec_krb5_oids,
 796         .client_start   = gensec_fake_gssapi_krb5_client_start,
 797         .server_start   = gensec_fake_gssapi_krb5_server_start,
 798         .update         = gensec_krb5_update,
 799         .magic          = gensec_fake_gssapi_krb5_magic,
 800         .session_key    = gensec_krb5_session_key,
 801         .session_info   = gensec_krb5_session_info,
 802         .have_feature   = gensec_krb5_have_feature,
 803         .enabled        = false,
 804         .kerberos       = true,
 805         .priority       = GENSEC_KRB5
 806 };
 807
 808 static const struct gensec_security_ops gensec_krb5_security_ops = {
 809         .name           = "krb5",
 810         .client_start   = gensec_krb5_client_start,
 811         .server_start   = gensec_krb5_server_start,
 812         .update         = gensec_krb5_update,
 813         .session_key    = gensec_krb5_session_key,
 814         .session_info   = gensec_krb5_session_info,
 815         .have_feature   = gensec_krb5_have_feature,
 816         .wrap           = gensec_krb5_wrap,
 817         .unwrap         = gensec_krb5_unwrap,
 818         .enabled        = true,
 819         .kerberos       = true,
 820         .priority       = GENSEC_KRB5
 821 };
 822
 823 _PUBLIC_ NTSTATUS gensec_krb5_init(void)
 824 {
 825         NTSTATUS ret;
 826
 827         ret = gensec_register(&gensec_krb5_security_ops);
 828         if (!NT_STATUS_IS_OK(ret)) {
 829                 DEBUG(0,("Failed to register '%s' gensec backend!\n",
 830                         gensec_krb5_security_ops.name));
 831                 return ret;
 832         }
 833
 834         ret = gensec_register(&gensec_fake_gssapi_krb5_security_ops);
 835         if (!NT_STATUS_IS_OK(ret)) {
 836                 DEBUG(0,("Failed to register '%s' gensec backend!\n",
 837                         gensec_krb5_security_ops.name));
 838                 return ret;
 839         }
 840
 841         return ret;
 842 }