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 "auth/auth.h"
  30 #include "lib/socket/socket.h"
  31 #include "lib/tsocket/tsocket.h"
  32 #include "librpc/rpc/dcerpc.h"
  33 #include "auth/credentials/credentials.h"
  34 #include "auth/gensec/gensec.h"
  35 #include "auth/gensec/gensec_proto.h"
  36 #include "param/param.h"
  37 #include "auth/auth_sam_reply.h"
  38
  39 enum GENSEC_KRB5_STATE {
  40         GENSEC_KRB5_SERVER_START,
  41         GENSEC_KRB5_CLIENT_START,
  42         GENSEC_KRB5_CLIENT_MUTUAL_AUTH,
  43         GENSEC_KRB5_DONE
  44 };
  45
  46 struct gensec_krb5_state {
  47         DATA_BLOB session_key;
  48         DATA_BLOB pac;
  49         enum GENSEC_KRB5_STATE state_position;
  50         struct smb_krb5_context *smb_krb5_context;
  51         krb5_auth_context auth_context;
  52         krb5_data enc_ticket;
  53         krb5_keyblock *keyblock;
  54         krb5_ticket *ticket;
  55         bool gssapi;
  56         krb5_flags ap_req_options;
  57 };
  58
  59 static int gensec_krb5_destroy(struct gensec_krb5_state *gensec_krb5_state)
  60 {
  61         if (!gensec_krb5_state->smb_krb5_context) {
  62                 /* We can't clean anything else up unless we started up this far */
  63                 return 0;
  64         }
  65         if (gensec_krb5_state->enc_ticket.length) {
  66                 kerberos_free_data_contents(gensec_krb5_state->smb_krb5_context->krb5_context,
  67                                             &gensec_krb5_state->enc_ticket);
  68         }
  69
  70         if (gensec_krb5_state->ticket) {
  71                 krb5_free_ticket(gensec_krb5_state->smb_krb5_context->krb5_context,
  72                                  gensec_krb5_state->ticket);
  73         }
  74
  75         /* ccache freed in a child destructor */
  76
  77         krb5_free_keyblock(gensec_krb5_state->smb_krb5_context->krb5_context,
  78                            gensec_krb5_state->keyblock);
  79
  80         if (gensec_krb5_state->auth_context) {
  81                 krb5_auth_con_free(gensec_krb5_state->smb_krb5_context->krb5_context,
  82                                    gensec_krb5_state->auth_context);
  83         }
  84
  85         return 0;
  86 }
  87
  88 static NTSTATUS gensec_krb5_start(struct gensec_security *gensec_security, bool gssapi)
  89 {
  90         krb5_error_code ret;
  91         struct gensec_krb5_state *gensec_krb5_state;
  92         struct cli_credentials *creds;
  93         const struct socket_address *peer_addr;
  94         const struct tsocket_address *tlocal_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 = gssapi;
 116
 117         talloc_set_destructor(gensec_krb5_state, gensec_krb5_destroy);
 118
 119         if (cli_credentials_get_krb5_context(creds,
 120                                              gensec_security->event_ctx,
 121                                              gensec_security->settings->lp_ctx, &gensec_krb5_state->smb_krb5_context)) {
 122                 talloc_free(gensec_krb5_state);
 123                 return NT_STATUS_INTERNAL_ERROR;
 124         }
 125
 126         ret = krb5_auth_con_init(gensec_krb5_state->smb_krb5_context->krb5_context, &gensec_krb5_state->auth_context);
 127         if (ret) {
 128                 DEBUG(1,("gensec_krb5_start: krb5_auth_con_init failed (%s)\n",
 129                          smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context,
 130                                                     ret, gensec_krb5_state)));
 131                 talloc_free(gensec_krb5_state);
 132                 return NT_STATUS_INTERNAL_ERROR;
 133         }
 134
 135         ret = krb5_auth_con_setflags(gensec_krb5_state->smb_krb5_context->krb5_context,
 136                                      gensec_krb5_state->auth_context,
 137                                      KRB5_AUTH_CONTEXT_DO_SEQUENCE);
 138         if (ret) {
 139                 DEBUG(1,("gensec_krb5_start: krb5_auth_con_setflags failed (%s)\n",
 140                          smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context,
 141                                                     ret, gensec_krb5_state)));
 142                 talloc_free(gensec_krb5_state);
 143                 return NT_STATUS_INTERNAL_ERROR;
 144         }
 145
 146         tlocal_addr = gensec_get_local_address(gensec_security);
 147         if (tlocal_addr) {
 148                 ssize_t socklen;
 149                 struct sockaddr_storage ss;
 150
 151                 socklen = tsocket_address_bsd_sockaddr(tlocal_addr,
 152                                 (struct sockaddr *) &ss,
 153                                 sizeof(struct sockaddr_storage));
 154                 if (socklen < 0) {
 155                         return NT_STATUS_INTERNAL_ERROR;
 156                 }
 157                 ret = krb5_sockaddr2address(gensec_krb5_state->smb_krb5_context->krb5_context,
 158                                 (const struct sockaddr *) &ss, &my_krb5_addr);
 159                 if (ret) {
 160                         DEBUG(1,("gensec_krb5_start: krb5_sockaddr2address (local) failed (%s)\n",
 161                                  smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context,
 162                                                             ret, gensec_krb5_state)));
 163                         talloc_free(gensec_krb5_state);
 164                         return NT_STATUS_INTERNAL_ERROR;
 165                 }
 166         }
 167
 168         peer_addr = gensec_get_peer_addr(gensec_security);
 169         if (peer_addr && peer_addr->sockaddr) {
 170                 ret = krb5_sockaddr2address(gensec_krb5_state->smb_krb5_context->krb5_context,
 171                                             peer_addr->sockaddr, &peer_krb5_addr);
 172                 if (ret) {
 173                         DEBUG(1,("gensec_krb5_start: krb5_sockaddr2address (local) failed (%s)\n",
 174                                  smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context,
 175                                                             ret, gensec_krb5_state)));
 176                         talloc_free(gensec_krb5_state);
 177                         return NT_STATUS_INTERNAL_ERROR;
 178                 }
 179         }
 180
 181         ret = krb5_auth_con_setaddrs(gensec_krb5_state->smb_krb5_context->krb5_context,
 182                                      gensec_krb5_state->auth_context,
 183                                      tlocal_addr ? &my_krb5_addr : NULL,
 184                                      peer_addr ? &peer_krb5_addr : NULL);
 185         if (ret) {
 186                 DEBUG(1,("gensec_krb5_start: krb5_auth_con_setaddrs failed (%s)\n",
 187                          smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context,
 188                                                     ret, gensec_krb5_state)));
 189                 talloc_free(gensec_krb5_state);
 190                 return NT_STATUS_INTERNAL_ERROR;
 191         }
 192
 193         return NT_STATUS_OK;
 194 }
 195
 196 static NTSTATUS gensec_krb5_common_server_start(struct gensec_security *gensec_security, bool gssapi)
 197 {
 198         NTSTATUS nt_status;
 199         struct gensec_krb5_state *gensec_krb5_state;
 200
 201         nt_status = gensec_krb5_start(gensec_security, gssapi);
 202         if (!NT_STATUS_IS_OK(nt_status)) {
 203                 return nt_status;
 204         }
 205
 206         gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
 207         gensec_krb5_state->state_position = GENSEC_KRB5_SERVER_START;
 208
 209         return NT_STATUS_OK;
 210 }
 211
 212 static NTSTATUS gensec_krb5_server_start(struct gensec_security *gensec_security)
 213 {
 214         return gensec_krb5_common_server_start(gensec_security, false);
 215 }
 216
 217 static NTSTATUS gensec_fake_gssapi_krb5_server_start(struct gensec_security *gensec_security)
 218 {
 219         return gensec_krb5_common_server_start(gensec_security, true);
 220 }
 221
 222 static NTSTATUS gensec_krb5_common_client_start(struct gensec_security *gensec_security, bool gssapi)
 223 {
 224         struct gensec_krb5_state *gensec_krb5_state;
 225         krb5_error_code ret;
 226         NTSTATUS nt_status;
 227         struct ccache_container *ccache_container;
 228         const char *hostname;
 229
 230         const char *principal;
 231         krb5_data in_data;
 232
 233         hostname = gensec_get_target_hostname(gensec_security);
 234         if (!hostname) {
 235                 DEBUG(1, ("Could not determine hostname for target computer, cannot use kerberos\n"));
 236                 return NT_STATUS_INVALID_PARAMETER;
 237         }
 238         if (is_ipaddress(hostname)) {
 239                 DEBUG(2, ("Cannot do krb5 to an IP address"));
 240                 return NT_STATUS_INVALID_PARAMETER;
 241         }
 242         if (strcmp(hostname, "localhost") == 0) {
 243                 DEBUG(2, ("krb5 to 'localhost' does not make sense"));
 244                 return NT_STATUS_INVALID_PARAMETER;
 245         }
 246
 247         nt_status = gensec_krb5_start(gensec_security, gssapi);
 248         if (!NT_STATUS_IS_OK(nt_status)) {
 249                 return nt_status;
 250         }
 251
 252         gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
 253         gensec_krb5_state->state_position = GENSEC_KRB5_CLIENT_START;
 254         gensec_krb5_state->ap_req_options = AP_OPTS_USE_SUBKEY;
 255
 256         if (gensec_krb5_state->gssapi) {
 257                 /* The Fake GSSAPI modal emulates Samba3, which does not do mutual authentication */
 258                 if (gensec_setting_bool(gensec_security->settings, "gensec_fake_gssapi_krb5", "mutual", false)) {
 259                         gensec_krb5_state->ap_req_options |= AP_OPTS_MUTUAL_REQUIRED;
 260                 }
 261         } else {
 262                 /* The wrapping for KPASSWD (a user of the raw KRB5 API) should be mutually authenticated */
 263                 if (gensec_setting_bool(gensec_security->settings, "gensec_krb5", "mutual", true)) {
 264                         gensec_krb5_state->ap_req_options |= AP_OPTS_MUTUAL_REQUIRED;
 265                 }
 266         }
 267
 268         principal = gensec_get_target_principal(gensec_security);
 269
 270         ret = cli_credentials_get_ccache(gensec_get_credentials(gensec_security),
 271                                          gensec_security->event_ctx,
 272                                          gensec_security->settings->lp_ctx, &ccache_container);
 273         switch (ret) {
 274         case 0:
 275                 break;
 276         case KRB5KDC_ERR_PREAUTH_FAILED:
 277                 return NT_STATUS_LOGON_FAILURE;
 278         case KRB5_KDC_UNREACH:
 279                 DEBUG(3, ("Cannot reach a KDC we require to contact %s\n", principal));
 280                 return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
 281         default:
 282                 DEBUG(1, ("gensec_krb5_start: Aquiring initiator credentials failed: %s\n", error_message(ret)));
 283                 return NT_STATUS_UNSUCCESSFUL;
 284         }
 285         in_data.length = 0;
 286
 287         if (principal && lp_client_use_spnego_principal(gensec_security->settings->lp_ctx)) {
 288                 krb5_principal target_principal;
 289                 ret = krb5_parse_name(gensec_krb5_state->smb_krb5_context->krb5_context, principal,
 290                                       &target_principal);
 291                 if (ret == 0) {
 292                         ret = krb5_mk_req_exact(gensec_krb5_state->smb_krb5_context->krb5_context,
 293                                                 &gensec_krb5_state->auth_context,
 294                                                 gensec_krb5_state->ap_req_options,
 295                                                 target_principal,
 296                                                 &in_data, ccache_container->ccache,
 297                                                 &gensec_krb5_state->enc_ticket);
 298                         krb5_free_principal(gensec_krb5_state->smb_krb5_context->krb5_context,
 299                                             target_principal);
 300                 }
 301         } else {
 302                 ret = krb5_mk_req(gensec_krb5_state->smb_krb5_context->krb5_context,
 303                                   &gensec_krb5_state->auth_context,
 304                                   gensec_krb5_state->ap_req_options,
 305                                   gensec_get_target_service(gensec_security),
 306                                   hostname,
 307                                   &in_data, ccache_container->ccache,
 308                                   &gensec_krb5_state->enc_ticket);
 309         }
 310         switch (ret) {
 311         case 0:
 312                 return NT_STATUS_OK;
 313         case KRB5KDC_ERR_S_PRINCIPAL_UNKNOWN:
 314                 DEBUG(3, ("Server [%s] is not registered with our KDC: %s\n",
 315                           hostname, smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context, ret, gensec_krb5_state)));
 316                 return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
 317         case KRB5_KDC_UNREACH:
 318                 DEBUG(3, ("Cannot reach a KDC we require to contact host [%s]: %s\n",
 319                           hostname, smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context, ret, gensec_krb5_state)));
 320                 return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
 321         case KRB5KDC_ERR_PREAUTH_FAILED:
 322         case KRB5KRB_AP_ERR_TKT_EXPIRED:
 323         case KRB5_CC_END:
 324                 /* Too much clock skew - we will need to kinit to re-skew the clock */
 325         case KRB5KRB_AP_ERR_SKEW:
 326         case KRB5_KDCREP_SKEW:
 327         {
 328                 DEBUG(3, ("kerberos (mk_req) failed: %s\n",
 329                           smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context, ret, gensec_krb5_state)));
 330                 /*fall through*/
 331         }
 332
 333         /* just don't print a message for these really ordinary messages */
 334         case KRB5_FCC_NOFILE:
 335         case KRB5_CC_NOTFOUND:
 336         case ENOENT:
 337
 338                 return NT_STATUS_UNSUCCESSFUL;
 339                 break;
 340
 341         default:
 342                 DEBUG(0, ("kerberos: %s\n",
 343                           smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context, ret, gensec_krb5_state)));
 344                 return NT_STATUS_UNSUCCESSFUL;
 345         }
 346 }
 347
 348 static NTSTATUS gensec_krb5_client_start(struct gensec_security *gensec_security)
 349 {
 350         return gensec_krb5_common_client_start(gensec_security, false);
 351 }
 352
 353 static NTSTATUS gensec_fake_gssapi_krb5_client_start(struct gensec_security *gensec_security)
 354 {
 355         return gensec_krb5_common_client_start(gensec_security, true);
 356 }
 357
 358 /**
 359  * Check if the packet is one for this mechansim
 360  *
 361  * @param gensec_security GENSEC state
 362  * @param in The request, as a DATA_BLOB
 363  * @return Error, INVALID_PARAMETER if it's not a packet for us
 364  *                or NT_STATUS_OK if the packet is ok.
 365  */
 366
 367 static NTSTATUS gensec_fake_gssapi_krb5_magic(struct gensec_security *gensec_security,
 368                                   const DATA_BLOB *in)
 369 {
 370         if (gensec_gssapi_check_oid(in, GENSEC_OID_KERBEROS5)) {
 371                 return NT_STATUS_OK;
 372         } else {
 373                 return NT_STATUS_INVALID_PARAMETER;
 374         }
 375 }
 376
 377
 378 /**
 379  * Next state function for the Krb5 GENSEC mechanism
 380  *
 381  * @param gensec_krb5_state KRB5 State
 382  * @param out_mem_ctx The TALLOC_CTX for *out to be allocated on
 383  * @param in The request, as a DATA_BLOB
 384  * @param out The reply, as an talloc()ed DATA_BLOB, on *out_mem_ctx
 385  * @return Error, MORE_PROCESSING_REQUIRED if a reply is sent,
 386  *                or NT_STATUS_OK if the user is authenticated.
 387  */
 388
 389 static NTSTATUS gensec_krb5_update(struct gensec_security *gensec_security,
 390                                    TALLOC_CTX *out_mem_ctx,
 391                                    const DATA_BLOB in, DATA_BLOB *out)
 392 {
 393         struct gensec_krb5_state *gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
 394         krb5_error_code ret = 0;
 395         NTSTATUS nt_status;
 396
 397         switch (gensec_krb5_state->state_position) {
 398         case GENSEC_KRB5_CLIENT_START:
 399         {
 400                 DATA_BLOB unwrapped_out;
 401
 402                 if (gensec_krb5_state->gssapi) {
 403                         unwrapped_out = data_blob_talloc(out_mem_ctx, gensec_krb5_state->enc_ticket.data, gensec_krb5_state->enc_ticket.length);
 404
 405                         /* wrap that up in a nice GSS-API wrapping */
 406                         *out = gensec_gssapi_gen_krb5_wrap(out_mem_ctx, &unwrapped_out, TOK_ID_KRB_AP_REQ);
 407                 } else {
 408                         *out = data_blob_talloc(out_mem_ctx, gensec_krb5_state->enc_ticket.data, gensec_krb5_state->enc_ticket.length);
 409                 }
 410                 if (gensec_krb5_state->ap_req_options & AP_OPTS_MUTUAL_REQUIRED) {
 411                         gensec_krb5_state->state_position = GENSEC_KRB5_CLIENT_MUTUAL_AUTH;
 412                         nt_status = NT_STATUS_MORE_PROCESSING_REQUIRED;
 413                 } else {
 414                         gensec_krb5_state->state_position = GENSEC_KRB5_DONE;
 415                         nt_status = NT_STATUS_OK;
 416                 }
 417                 return nt_status;
 418         }
 419
 420         case GENSEC_KRB5_CLIENT_MUTUAL_AUTH:
 421         {
 422                 DATA_BLOB unwrapped_in;
 423                 krb5_data inbuf;
 424                 krb5_ap_rep_enc_part *repl = NULL;
 425                 uint8_t tok_id[2];
 426
 427                 if (gensec_krb5_state->gssapi) {
 428                         if (!gensec_gssapi_parse_krb5_wrap(out_mem_ctx, &in, &unwrapped_in, tok_id)) {
 429                                 DEBUG(1,("gensec_gssapi_parse_krb5_wrap(mutual authentication) failed to parse\n"));
 430                                 dump_data_pw("Mutual authentication message:\n", in.data, in.length);
 431                                 return NT_STATUS_INVALID_PARAMETER;
 432                         }
 433                 } else {
 434                         unwrapped_in = in;
 435                 }
 436                 /* TODO: check the tok_id */
 437
 438                 inbuf.data = unwrapped_in.data;
 439                 inbuf.length = unwrapped_in.length;
 440                 ret = krb5_rd_rep(gensec_krb5_state->smb_krb5_context->krb5_context,
 441                                   gensec_krb5_state->auth_context,
 442                                   &inbuf, &repl);
 443                 if (ret) {
 444                         DEBUG(1,("krb5_rd_rep (mutual authentication) failed (%s)\n",
 445                                  smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context, ret, out_mem_ctx)));
 446                         dump_data_pw("Mutual authentication message:\n", (uint8_t *)inbuf.data, inbuf.length);
 447                         nt_status = NT_STATUS_ACCESS_DENIED;
 448                 } else {
 449                         *out = data_blob(NULL, 0);
 450                         nt_status = NT_STATUS_OK;
 451                         gensec_krb5_state->state_position = GENSEC_KRB5_DONE;
 452                 }
 453                 if (repl) {
 454                         krb5_free_ap_rep_enc_part(gensec_krb5_state->smb_krb5_context->krb5_context, repl);
 455                 }
 456                 return nt_status;
 457         }
 458
 459         case GENSEC_KRB5_SERVER_START:
 460         {
 461                 DATA_BLOB unwrapped_in;
 462                 DATA_BLOB unwrapped_out = data_blob(NULL, 0);
 463                 krb5_data inbuf, outbuf;
 464                 uint8_t tok_id[2];
 465                 struct keytab_container *keytab;
 466                 krb5_principal server_in_keytab;
 467
 468                 if (!in.data) {
 469                         return NT_STATUS_INVALID_PARAMETER;
 470                 }
 471
 472                 /* Grab the keytab, however generated */
 473                 ret = cli_credentials_get_keytab(gensec_get_credentials(gensec_security),
 474                                                  gensec_security->event_ctx,
 475                                                  gensec_security->settings->lp_ctx, &keytab);
 476                 if (ret) {
 477                         return NT_STATUS_CANT_ACCESS_DOMAIN_INFO;
 478                 }
 479
 480                 /* This ensures we lookup the correct entry in that keytab */
 481                 ret = principal_from_credentials(out_mem_ctx, gensec_get_credentials(gensec_security),
 482                                                  gensec_krb5_state->smb_krb5_context,
 483                                                  &server_in_keytab);
 484
 485                 if (ret) {
 486                         return NT_STATUS_CANT_ACCESS_DOMAIN_INFO;
 487                 }
 488
 489                 /* Parse the GSSAPI wrapping, if it's there... (win2k3 allows it to be omited) */
 490                 if (gensec_krb5_state->gssapi
 491                     && gensec_gssapi_parse_krb5_wrap(out_mem_ctx, &in, &unwrapped_in, tok_id)) {
 492                         inbuf.data = unwrapped_in.data;
 493                         inbuf.length = unwrapped_in.length;
 494                 } else {
 495                         inbuf.data = in.data;
 496                         inbuf.length = in.length;
 497                 }
 498
 499                 ret = smb_rd_req_return_stuff(gensec_krb5_state->smb_krb5_context->krb5_context,
 500                                               &gensec_krb5_state->auth_context,
 501                                               &inbuf, keytab->keytab, server_in_keytab,
 502                                               &outbuf,
 503                                               &gensec_krb5_state->ticket,
 504                                               &gensec_krb5_state->keyblock);
 505
 506                 if (ret) {
 507                         return NT_STATUS_LOGON_FAILURE;
 508                 }
 509                 unwrapped_out.data = (uint8_t *)outbuf.data;
 510                 unwrapped_out.length = outbuf.length;
 511                 gensec_krb5_state->state_position = GENSEC_KRB5_DONE;
 512                 /* wrap that up in a nice GSS-API wrapping */
 513                 if (gensec_krb5_state->gssapi) {
 514                         *out = gensec_gssapi_gen_krb5_wrap(out_mem_ctx, &unwrapped_out, TOK_ID_KRB_AP_REP);
 515                 } else {
 516                         *out = data_blob_talloc(out_mem_ctx, outbuf.data, outbuf.length);
 517                 }
 518                 krb5_data_free(&outbuf);
 519                 return NT_STATUS_OK;
 520         }
 521
 522         case GENSEC_KRB5_DONE:
 523         default:
 524                 /* Asking too many times... */
 525                 return NT_STATUS_INVALID_PARAMETER;
 526         }
 527 }
 528
 529 static NTSTATUS gensec_krb5_session_key(struct gensec_security *gensec_security,
 530                                         DATA_BLOB *session_key)
 531 {
 532         struct gensec_krb5_state *gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
 533         krb5_context context = gensec_krb5_state->smb_krb5_context->krb5_context;
 534         krb5_auth_context auth_context = gensec_krb5_state->auth_context;
 535         krb5_keyblock *skey;
 536         krb5_error_code err = -1;
 537
 538         if (gensec_krb5_state->state_position != GENSEC_KRB5_DONE) {
 539                 return NT_STATUS_NO_USER_SESSION_KEY;
 540         }
 541
 542         if (gensec_krb5_state->session_key.data) {
 543                 *session_key = gensec_krb5_state->session_key;
 544                 return NT_STATUS_OK;
 545         }
 546
 547         switch (gensec_security->gensec_role) {
 548         case GENSEC_CLIENT:
 549                 err = krb5_auth_con_getlocalsubkey(context, auth_context, &skey);
 550                 break;
 551         case GENSEC_SERVER:
 552                 err = krb5_auth_con_getremotesubkey(context, auth_context, &skey);
 553                 break;
 554         }
 555         if (err == 0 && skey != NULL) {
 556                 DEBUG(10, ("Got KRB5 session key of length %d\n",
 557                            (int)KRB5_KEY_LENGTH(skey)));
 558                 gensec_krb5_state->session_key = data_blob_talloc(gensec_krb5_state,
 559                                                 KRB5_KEY_DATA(skey), KRB5_KEY_LENGTH(skey));
 560                 *session_key = gensec_krb5_state->session_key;
 561                 dump_data_pw("KRB5 Session Key:\n", session_key->data, session_key->length);
 562
 563                 krb5_free_keyblock(context, skey);
 564                 return NT_STATUS_OK;
 565         } else {
 566                 DEBUG(10, ("KRB5 error getting session key %d\n", err));
 567                 return NT_STATUS_NO_USER_SESSION_KEY;
 568         }
 569 }
 570
 571 static NTSTATUS gensec_krb5_session_info(struct gensec_security *gensec_security,
 572                                          struct auth_session_info **_session_info)
 573 {
 574         NTSTATUS nt_status = NT_STATUS_UNSUCCESSFUL;
 575         struct gensec_krb5_state *gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
 576         krb5_context context = gensec_krb5_state->smb_krb5_context->krb5_context;
 577         struct auth_serversupplied_info *server_info = NULL;
 578         struct auth_session_info *session_info = NULL;
 579         struct PAC_LOGON_INFO *logon_info;
 580
 581         krb5_principal client_principal;
 582         char *principal_string;
 583
 584         DATA_BLOB pac;
 585         krb5_data pac_data;
 586
 587         krb5_error_code ret;
 588
 589         TALLOC_CTX *mem_ctx = talloc_new(gensec_security);
 590         if (!mem_ctx) {
 591                 return NT_STATUS_NO_MEMORY;
 592         }
 593
 594         ret = krb5_ticket_get_client(context, gensec_krb5_state->ticket, &client_principal);
 595         if (ret) {
 596                 DEBUG(5, ("krb5_ticket_get_client failed to get cleint 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_unparse_name(gensec_krb5_state->smb_krb5_context->krb5_context,
 604                                 client_principal, &principal_string);
 605         if (ret) {
 606                 DEBUG(1, ("Unable to parse client principal: %s\n",
 607                           smb_get_krb5_error_message(context,
 608                                                      ret, mem_ctx)));
 609                 talloc_free(mem_ctx);
 610                 return NT_STATUS_NO_MEMORY;
 611         }
 612
 613         ret = krb5_ticket_get_authorization_data_type(context, gensec_krb5_state->ticket,
 614                                                       KRB5_AUTHDATA_WIN2K_PAC,
 615                                                       &pac_data);
 616
 617         if (ret && gensec_setting_bool(gensec_security->settings, "gensec", "require_pac", false)) {
 618                 DEBUG(1, ("Unable to find PAC in ticket from %s, failing to allow access: %s \n",
 619                           principal_string,
 620                           smb_get_krb5_error_message(context,
 621                                                      ret, mem_ctx)));
 622                 krb5_free_principal(context, client_principal);
 623                 free(principal_string);
 624                 return NT_STATUS_ACCESS_DENIED;
 625         } else if (ret) {
 626                 /* NO pac */
 627                 DEBUG(5, ("krb5_ticket_get_authorization_data_type failed to find PAC: %s\n",
 628                           smb_get_krb5_error_message(context,
 629                                                      ret, mem_ctx)));
 630                 if (gensec_security->auth_context &&
 631                     !gensec_setting_bool(gensec_security->settings, "gensec", "require_pac", false)) {
 632                         DEBUG(1, ("Unable to find PAC for %s, resorting to local user lookup: %s",
 633                                   principal_string, smb_get_krb5_error_message(context,
 634                                                      ret, mem_ctx)));
 635                         nt_status = gensec_security->auth_context->get_server_info_principal(mem_ctx,
 636                                                                                              gensec_security->auth_context,
 637                                                                                              principal_string,
 638                                                                                              &server_info);
 639                         if (!NT_STATUS_IS_OK(nt_status)) {
 640                                 talloc_free(mem_ctx);
 641                                 return nt_status;
 642                         }
 643                 } else {
 644                         DEBUG(1, ("Unable to find PAC in ticket from %s, failing to allow access\n",
 645                                   principal_string));
 646                         return NT_STATUS_ACCESS_DENIED;
 647                 }
 648
 649                 krb5_free_principal(context, client_principal);
 650                 free(principal_string);
 651
 652                 if (!NT_STATUS_IS_OK(nt_status)) {
 653                         talloc_free(mem_ctx);
 654                         return nt_status;
 655                 }
 656         } else {
 657                 /* Found pac */
 658                 union netr_Validation validation;
 659                 free(principal_string);
 660
 661                 pac = data_blob_talloc(mem_ctx, pac_data.data, pac_data.length);
 662                 if (!pac.data) {
 663                         krb5_free_principal(context, client_principal);
 664                         talloc_free(mem_ctx);
 665                         return NT_STATUS_NO_MEMORY;
 666                 }
 667
 668                 /* decode and verify the pac */
 669                 nt_status = kerberos_pac_logon_info(gensec_krb5_state,
 670                                                     gensec_security->settings->iconv_convenience,
 671                                                     &logon_info, pac,
 672                                                     gensec_krb5_state->smb_krb5_context->krb5_context,
 673                                                     NULL, gensec_krb5_state->keyblock,
 674                                                     client_principal,
 675                                                     gensec_krb5_state->ticket->ticket.authtime, NULL);
 676                 krb5_free_principal(context, client_principal);
 677
 678                 if (!NT_STATUS_IS_OK(nt_status)) {
 679                         talloc_free(mem_ctx);
 680                         return nt_status;
 681                 }
 682
 683                 validation.sam3 = &logon_info->info3;
 684                 nt_status = make_server_info_netlogon_validation(mem_ctx,
 685                                                                  NULL,
 686                                                                  3, &validation,
 687                                                                  &server_info);
 688                 if (!NT_STATUS_IS_OK(nt_status)) {
 689                         talloc_free(mem_ctx);
 690                         return nt_status;
 691                 }
 692         }
 693
 694         /* references the server_info into the session_info */
 695         nt_status = auth_generate_session_info(mem_ctx, gensec_security->event_ctx, gensec_security->settings->lp_ctx, server_info, &session_info);
 696
 697         if (!NT_STATUS_IS_OK(nt_status)) {
 698                 talloc_free(mem_ctx);
 699                 return nt_status;
 700         }
 701
 702         nt_status = gensec_krb5_session_key(gensec_security, &session_info->session_key);
 703
 704         if (!NT_STATUS_IS_OK(nt_status)) {
 705                 talloc_free(mem_ctx);
 706                 return nt_status;
 707         }
 708
 709         *_session_info = session_info;
 710
 711         talloc_steal(gensec_krb5_state, session_info);
 712         talloc_free(mem_ctx);
 713         return NT_STATUS_OK;
 714 }
 715
 716 static NTSTATUS gensec_krb5_wrap(struct gensec_security *gensec_security,
 717                                    TALLOC_CTX *mem_ctx,
 718                                    const DATA_BLOB *in,
 719                                    DATA_BLOB *out)
 720 {
 721         struct gensec_krb5_state *gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
 722         krb5_context context = gensec_krb5_state->smb_krb5_context->krb5_context;
 723         krb5_auth_context auth_context = gensec_krb5_state->auth_context;
 724         krb5_error_code ret;
 725         krb5_data input, output;
 726         input.length = in->length;
 727         input.data = in->data;
 728
 729         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
 730                 ret = krb5_mk_priv(context, auth_context, &input, &output, NULL);
 731                 if (ret) {
 732                         DEBUG(1, ("krb5_mk_priv failed: %s\n",
 733                                   smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context,
 734                                                              ret, mem_ctx)));
 735                         return NT_STATUS_ACCESS_DENIED;
 736                 }
 737                 *out = data_blob_talloc(mem_ctx, output.data, output.length);
 738
 739                 krb5_data_free(&output);
 740         } else {
 741                 return NT_STATUS_ACCESS_DENIED;
 742         }
 743         return NT_STATUS_OK;
 744 }
 745
 746 static NTSTATUS gensec_krb5_unwrap(struct gensec_security *gensec_security,
 747                                      TALLOC_CTX *mem_ctx,
 748                                      const DATA_BLOB *in,
 749                                      DATA_BLOB *out)
 750 {
 751         struct gensec_krb5_state *gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
 752         krb5_context context = gensec_krb5_state->smb_krb5_context->krb5_context;
 753         krb5_auth_context auth_context = gensec_krb5_state->auth_context;
 754         krb5_error_code ret;
 755         krb5_data input, output;
 756         krb5_replay_data replay;
 757         input.length = in->length;
 758         input.data = in->data;
 759
 760         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
 761                 ret = krb5_rd_priv(context, auth_context, &input, &output, &replay);
 762                 if (ret) {
 763                         DEBUG(1, ("krb5_rd_priv failed: %s\n",
 764                                   smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context,
 765                                                              ret, mem_ctx)));
 766                         return NT_STATUS_ACCESS_DENIED;
 767                 }
 768                 *out = data_blob_talloc(mem_ctx, output.data, output.length);
 769
 770                 krb5_data_free(&output);
 771         } else {
 772                 return NT_STATUS_ACCESS_DENIED;
 773         }
 774         return NT_STATUS_OK;
 775 }
 776
 777 static bool gensec_krb5_have_feature(struct gensec_security *gensec_security,
 778                                      uint32_t feature)
 779 {
 780         struct gensec_krb5_state *gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
 781         if (feature & GENSEC_FEATURE_SESSION_KEY) {
 782                 return true;
 783         }
 784         if (!gensec_krb5_state->gssapi &&
 785             (feature & GENSEC_FEATURE_SEAL)) {
 786                 return true;
 787         }
 788
 789         return false;
 790 }
 791
 792 static const char *gensec_krb5_oids[] = {
 793         GENSEC_OID_KERBEROS5,
 794         GENSEC_OID_KERBEROS5_OLD,
 795         NULL
 796 };
 797
 798 static const struct gensec_security_ops gensec_fake_gssapi_krb5_security_ops = {
 799         .name           = "fake_gssapi_krb5",
 800         .auth_type      = DCERPC_AUTH_TYPE_KRB5,
 801         .oid            = gensec_krb5_oids,
 802         .client_start   = gensec_fake_gssapi_krb5_client_start,
 803         .server_start   = gensec_fake_gssapi_krb5_server_start,
 804         .update         = gensec_krb5_update,
 805         .magic          = gensec_fake_gssapi_krb5_magic,
 806         .session_key    = gensec_krb5_session_key,
 807         .session_info   = gensec_krb5_session_info,
 808         .have_feature   = gensec_krb5_have_feature,
 809         .enabled        = false,
 810         .kerberos       = true,
 811         .priority       = GENSEC_KRB5
 812 };
 813
 814 static const struct gensec_security_ops gensec_krb5_security_ops = {
 815         .name           = "krb5",
 816         .client_start   = gensec_krb5_client_start,
 817         .server_start   = gensec_krb5_server_start,
 818         .update         = gensec_krb5_update,
 819         .session_key    = gensec_krb5_session_key,
 820         .session_info   = gensec_krb5_session_info,
 821         .have_feature   = gensec_krb5_have_feature,
 822         .wrap           = gensec_krb5_wrap,
 823         .unwrap         = gensec_krb5_unwrap,
 824         .enabled        = true,
 825         .kerberos       = true,
 826         .priority       = GENSEC_KRB5
 827 };
 828
 829 _PUBLIC_ NTSTATUS gensec_krb5_init(void)
 830 {
 831         NTSTATUS ret;
 832
 833         ret = gensec_register(&gensec_krb5_security_ops);
 834         if (!NT_STATUS_IS_OK(ret)) {
 835                 DEBUG(0,("Failed to register '%s' gensec backend!\n",
 836                         gensec_krb5_security_ops.name));
 837                 return ret;
 838         }
 839
 840         ret = gensec_register(&gensec_fake_gssapi_krb5_security_ops);
 841         if (!NT_STATUS_IS_OK(ret)) {
 842                 DEBUG(0,("Failed to register '%s' gensec backend!\n",
 843                         gensec_krb5_security_ops.name));
 844                 return ret;
 845         }
 846
 847         return ret;
 848 }