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/credentials/credentials_krb5.h"
  35 #include "auth/kerberos/kerberos_credentials.h"
  36 #include "auth/gensec/gensec.h"
  37 #include "auth/gensec/gensec_proto.h"
  38 #include "auth/gensec/gensec_toplevel_proto.h"
  39 #include "param/param.h"
  40 #include "auth/auth_sam_reply.h"
  41 #include "lib/util/util_net.h"
  42
  43 _PUBLIC_ NTSTATUS gensec_krb5_init(void);
  44
  45 enum GENSEC_KRB5_STATE {
  46         GENSEC_KRB5_SERVER_START,
  47         GENSEC_KRB5_CLIENT_START,
  48         GENSEC_KRB5_CLIENT_MUTUAL_AUTH,
  49         GENSEC_KRB5_DONE
  50 };
  51
  52 struct gensec_krb5_state {
  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 tsocket_address *tlocal_addr, *tremote_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->gssapi = gssapi;
 117
 118         talloc_set_destructor(gensec_krb5_state, gensec_krb5_destroy);
 119
 120         if (cli_credentials_get_krb5_context(creds,
 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                         talloc_free(gensec_krb5_state);
 156                         return NT_STATUS_INTERNAL_ERROR;
 157                 }
 158                 ret = krb5_sockaddr2address(gensec_krb5_state->smb_krb5_context->krb5_context,
 159                                 (const struct sockaddr *) &ss, &my_krb5_addr);
 160                 if (ret) {
 161                         DEBUG(1,("gensec_krb5_start: krb5_sockaddr2address (local) failed (%s)\n",
 162                                  smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context,
 163                                                             ret, gensec_krb5_state)));
 164                         talloc_free(gensec_krb5_state);
 165                         return NT_STATUS_INTERNAL_ERROR;
 166                 }
 167         }
 168
 169         tremote_addr = gensec_get_remote_address(gensec_security);
 170         if (tremote_addr) {
 171                 ssize_t socklen;
 172                 struct sockaddr_storage ss;
 173
 174                 socklen = tsocket_address_bsd_sockaddr(tremote_addr,
 175                                 (struct sockaddr *) &ss,
 176                                 sizeof(struct sockaddr_storage));
 177                 if (socklen < 0) {
 178                         talloc_free(gensec_krb5_state);
 179                         return NT_STATUS_INTERNAL_ERROR;
 180                 }
 181                 ret = krb5_sockaddr2address(gensec_krb5_state->smb_krb5_context->krb5_context,
 182                                 (const struct sockaddr *) &ss, &peer_krb5_addr);
 183                 if (ret) {
 184                         DEBUG(1,("gensec_krb5_start: krb5_sockaddr2address (local) failed (%s)\n",
 185                                  smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context,
 186                                                             ret, gensec_krb5_state)));
 187                         talloc_free(gensec_krb5_state);
 188                         return NT_STATUS_INTERNAL_ERROR;
 189                 }
 190         }
 191
 192         ret = krb5_auth_con_setaddrs(gensec_krb5_state->smb_krb5_context->krb5_context,
 193                                      gensec_krb5_state->auth_context,
 194                                      tlocal_addr ? &my_krb5_addr : NULL,
 195                                      tremote_addr ? &peer_krb5_addr : NULL);
 196         if (ret) {
 197                 DEBUG(1,("gensec_krb5_start: krb5_auth_con_setaddrs failed (%s)\n",
 198                          smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context,
 199                                                     ret, gensec_krb5_state)));
 200                 talloc_free(gensec_krb5_state);
 201                 return NT_STATUS_INTERNAL_ERROR;
 202         }
 203
 204         return NT_STATUS_OK;
 205 }
 206
 207 static NTSTATUS gensec_krb5_common_server_start(struct gensec_security *gensec_security, bool gssapi)
 208 {
 209         NTSTATUS nt_status;
 210         struct gensec_krb5_state *gensec_krb5_state;
 211
 212         nt_status = gensec_krb5_start(gensec_security, gssapi);
 213         if (!NT_STATUS_IS_OK(nt_status)) {
 214                 return nt_status;
 215         }
 216
 217         gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
 218         gensec_krb5_state->state_position = GENSEC_KRB5_SERVER_START;
 219
 220         return NT_STATUS_OK;
 221 }
 222
 223 static NTSTATUS gensec_krb5_server_start(struct gensec_security *gensec_security)
 224 {
 225         return gensec_krb5_common_server_start(gensec_security, false);
 226 }
 227
 228 static NTSTATUS gensec_fake_gssapi_krb5_server_start(struct gensec_security *gensec_security)
 229 {
 230         return gensec_krb5_common_server_start(gensec_security, true);
 231 }
 232
 233 static NTSTATUS gensec_krb5_common_client_start(struct gensec_security *gensec_security, bool gssapi)
 234 {
 235         const char *hostname;
 236         struct gensec_krb5_state *gensec_krb5_state;
 237         NTSTATUS nt_status;
 238         hostname = gensec_get_target_hostname(gensec_security);
 239         if (!hostname) {
 240                 DEBUG(1, ("Could not determine hostname for target computer, cannot use kerberos\n"));
 241                 return NT_STATUS_INVALID_PARAMETER;
 242         }
 243         if (is_ipaddress(hostname)) {
 244                 DEBUG(2, ("Cannot do krb5 to an IP address"));
 245                 return NT_STATUS_INVALID_PARAMETER;
 246         }
 247         if (strcmp(hostname, "localhost") == 0) {
 248                 DEBUG(2, ("krb5 to 'localhost' does not make sense"));
 249                 return NT_STATUS_INVALID_PARAMETER;
 250         }
 251
 252         nt_status = gensec_krb5_start(gensec_security, gssapi);
 253         if (!NT_STATUS_IS_OK(nt_status)) {
 254                 return nt_status;
 255         }
 256
 257         gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
 258         gensec_krb5_state->state_position = GENSEC_KRB5_CLIENT_START;
 259         gensec_krb5_state->ap_req_options = AP_OPTS_USE_SUBKEY;
 260
 261         if (gensec_krb5_state->gssapi) {
 262                 /* The Fake GSSAPI modal emulates Samba3, which does not do mutual authentication */
 263                 if (gensec_setting_bool(gensec_security->settings, "gensec_fake_gssapi_krb5", "mutual", false)) {
 264                         gensec_krb5_state->ap_req_options |= AP_OPTS_MUTUAL_REQUIRED;
 265                 }
 266         } else {
 267                 /* The wrapping for KPASSWD (a user of the raw KRB5 API) should be mutually authenticated */
 268                 if (gensec_setting_bool(gensec_security->settings, "gensec_krb5", "mutual", true)) {
 269                         gensec_krb5_state->ap_req_options |= AP_OPTS_MUTUAL_REQUIRED;
 270                 }
 271         }
 272         return NT_STATUS_OK;
 273 }
 274
 275 static NTSTATUS gensec_krb5_common_client_creds(struct gensec_security *gensec_security,
 276                                                 struct tevent_context *ev,
 277                                                 bool gssapi)
 278 {
 279         struct gensec_krb5_state *gensec_krb5_state;
 280         krb5_error_code ret;
 281         struct ccache_container *ccache_container;
 282         const char *error_string;
 283         const char *principal;
 284         const char *hostname;
 285         krb5_data in_data;
 286         struct tevent_context *previous_ev;
 287
 288         gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
 289
 290         principal = gensec_get_target_principal(gensec_security);
 291         hostname = gensec_get_target_hostname(gensec_security);
 292
 293         ret = cli_credentials_get_ccache(gensec_get_credentials(gensec_security),
 294                                          ev,
 295                                          gensec_security->settings->lp_ctx, &ccache_container, &error_string);
 296         switch (ret) {
 297         case 0:
 298                 break;
 299         case KRB5KDC_ERR_PREAUTH_FAILED:
 300         case KRB5KDC_ERR_C_PRINCIPAL_UNKNOWN:
 301                 return NT_STATUS_LOGON_FAILURE;
 302         case KRB5_KDC_UNREACH:
 303                 DEBUG(3, ("Cannot reach a KDC we require to contact %s: %s\n", principal, error_string));
 304                 return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
 305         case KRB5_CC_NOTFOUND:
 306         case KRB5_CC_END:
 307                 DEBUG(3, ("Error preparing credentials we require to contact %s : %s\n", principal, error_string));
 308                 return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
 309         default:
 310                 DEBUG(1, ("gensec_krb5_start: Aquiring initiator credentials failed: %s\n", error_string));
 311                 return NT_STATUS_UNSUCCESSFUL;
 312         }
 313         in_data.length = 0;
 314
 315         /* Do this every time, in case we have weird recursive issues here */
 316         ret = smb_krb5_context_set_event_ctx(gensec_krb5_state->smb_krb5_context, ev, &previous_ev);
 317         if (ret != 0) {
 318                 DEBUG(1, ("gensec_krb5_start: Setting event context failed\n"));
 319                 return NT_STATUS_NO_MEMORY;
 320         }
 321         if (principal) {
 322                 krb5_principal target_principal;
 323                 ret = krb5_parse_name(gensec_krb5_state->smb_krb5_context->krb5_context, principal,
 324                                       &target_principal);
 325                 if (ret == 0) {
 326                         ret = krb5_mk_req_exact(gensec_krb5_state->smb_krb5_context->krb5_context,
 327                                                 &gensec_krb5_state->auth_context,
 328                                                 gensec_krb5_state->ap_req_options,
 329                                                 target_principal,
 330                                                 &in_data, ccache_container->ccache,
 331                                                 &gensec_krb5_state->enc_ticket);
 332                         krb5_free_principal(gensec_krb5_state->smb_krb5_context->krb5_context,
 333                                             target_principal);
 334                 }
 335         } else {
 336                 ret = krb5_mk_req(gensec_krb5_state->smb_krb5_context->krb5_context,
 337                                   &gensec_krb5_state->auth_context,
 338                                   gensec_krb5_state->ap_req_options,
 339                                   gensec_get_target_service(gensec_security),
 340                                   hostname,
 341                                   &in_data, ccache_container->ccache,
 342                                   &gensec_krb5_state->enc_ticket);
 343         }
 344
 345         smb_krb5_context_remove_event_ctx(gensec_krb5_state->smb_krb5_context, previous_ev, ev);
 346
 347         switch (ret) {
 348         case 0:
 349                 return NT_STATUS_OK;
 350         case KRB5KDC_ERR_S_PRINCIPAL_UNKNOWN:
 351                 DEBUG(3, ("Server [%s] is not registered with our KDC: %s\n",
 352                           hostname, smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context, ret, gensec_krb5_state)));
 353                 return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
 354         case KRB5_KDC_UNREACH:
 355                 DEBUG(3, ("Cannot reach a KDC we require to contact host [%s]: %s\n",
 356                           hostname, smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context, ret, gensec_krb5_state)));
 357                 return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
 358         case KRB5KDC_ERR_PREAUTH_FAILED:
 359         case KRB5KRB_AP_ERR_TKT_EXPIRED:
 360         case KRB5_CC_END:
 361                 /* Too much clock skew - we will need to kinit to re-skew the clock */
 362         case KRB5KRB_AP_ERR_SKEW:
 363         case KRB5_KDCREP_SKEW:
 364         {
 365                 DEBUG(3, ("kerberos (mk_req) failed: %s\n",
 366                           smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context, ret, gensec_krb5_state)));
 367                 /*fall through*/
 368         }
 369
 370         /* just don't print a message for these really ordinary messages */
 371         case KRB5_FCC_NOFILE:
 372         case KRB5_CC_NOTFOUND:
 373         case ENOENT:
 374
 375                 return NT_STATUS_UNSUCCESSFUL;
 376                 break;
 377
 378         default:
 379                 DEBUG(0, ("kerberos: %s\n",
 380                           smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context, ret, gensec_krb5_state)));
 381                 return NT_STATUS_UNSUCCESSFUL;
 382         }
 383 }
 384
 385 static NTSTATUS gensec_krb5_client_start(struct gensec_security *gensec_security)
 386 {
 387         return gensec_krb5_common_client_start(gensec_security, false);
 388 }
 389
 390 static NTSTATUS gensec_fake_gssapi_krb5_client_start(struct gensec_security *gensec_security)
 391 {
 392         return gensec_krb5_common_client_start(gensec_security, true);
 393 }
 394
 395 /**
 396  * Next state function for the Krb5 GENSEC mechanism
 397  *
 398  * @param gensec_krb5_state KRB5 State
 399  * @param out_mem_ctx The TALLOC_CTX for *out to be allocated on
 400  * @param in The request, as a DATA_BLOB
 401  * @param out The reply, as an talloc()ed DATA_BLOB, on *out_mem_ctx
 402  * @return Error, MORE_PROCESSING_REQUIRED if a reply is sent,
 403  *                or NT_STATUS_OK if the user is authenticated.
 404  */
 405
 406 static NTSTATUS gensec_krb5_update(struct gensec_security *gensec_security,
 407                                    TALLOC_CTX *out_mem_ctx,
 408                                    struct tevent_context *ev,
 409                                    const DATA_BLOB in, DATA_BLOB *out)
 410 {
 411         struct gensec_krb5_state *gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
 412         krb5_error_code ret = 0;
 413         NTSTATUS nt_status;
 414
 415         switch (gensec_krb5_state->state_position) {
 416         case GENSEC_KRB5_CLIENT_START:
 417         {
 418                 DATA_BLOB unwrapped_out;
 419
 420                 nt_status = gensec_krb5_common_client_creds(gensec_security, ev, gensec_krb5_state->gssapi);
 421                 if (!NT_STATUS_IS_OK(nt_status)) {
 422                         return nt_status;
 423                 }
 424
 425                 if (gensec_krb5_state->gssapi) {
 426                         unwrapped_out = data_blob_talloc(out_mem_ctx, gensec_krb5_state->enc_ticket.data, gensec_krb5_state->enc_ticket.length);
 427
 428                         /* wrap that up in a nice GSS-API wrapping */
 429                         *out = gensec_gssapi_gen_krb5_wrap(out_mem_ctx, &unwrapped_out, TOK_ID_KRB_AP_REQ);
 430                 } else {
 431                         *out = data_blob_talloc(out_mem_ctx, gensec_krb5_state->enc_ticket.data, gensec_krb5_state->enc_ticket.length);
 432                 }
 433                 if (gensec_krb5_state->ap_req_options & AP_OPTS_MUTUAL_REQUIRED) {
 434                         gensec_krb5_state->state_position = GENSEC_KRB5_CLIENT_MUTUAL_AUTH;
 435                         nt_status = NT_STATUS_MORE_PROCESSING_REQUIRED;
 436                 } else {
 437                         gensec_krb5_state->state_position = GENSEC_KRB5_DONE;
 438                         nt_status = NT_STATUS_OK;
 439                 }
 440                 return nt_status;
 441         }
 442
 443         case GENSEC_KRB5_CLIENT_MUTUAL_AUTH:
 444         {
 445                 DATA_BLOB unwrapped_in;
 446                 krb5_data inbuf;
 447                 krb5_ap_rep_enc_part *repl = NULL;
 448                 uint8_t tok_id[2];
 449
 450                 if (gensec_krb5_state->gssapi) {
 451                         if (!gensec_gssapi_parse_krb5_wrap(out_mem_ctx, &in, &unwrapped_in, tok_id)) {
 452                                 DEBUG(1,("gensec_gssapi_parse_krb5_wrap(mutual authentication) failed to parse\n"));
 453                                 dump_data_pw("Mutual authentication message:\n", in.data, in.length);
 454                                 return NT_STATUS_INVALID_PARAMETER;
 455                         }
 456                 } else {
 457                         unwrapped_in = in;
 458                 }
 459                 /* TODO: check the tok_id */
 460
 461                 inbuf.data = unwrapped_in.data;
 462                 inbuf.length = unwrapped_in.length;
 463                 ret = krb5_rd_rep(gensec_krb5_state->smb_krb5_context->krb5_context,
 464                                   gensec_krb5_state->auth_context,
 465                                   &inbuf, &repl);
 466                 if (ret) {
 467                         DEBUG(1,("krb5_rd_rep (mutual authentication) failed (%s)\n",
 468                                  smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context, ret, out_mem_ctx)));
 469                         dump_data_pw("Mutual authentication message:\n", (uint8_t *)inbuf.data, inbuf.length);
 470                         nt_status = NT_STATUS_ACCESS_DENIED;
 471                 } else {
 472                         *out = data_blob(NULL, 0);
 473                         nt_status = NT_STATUS_OK;
 474                         gensec_krb5_state->state_position = GENSEC_KRB5_DONE;
 475                 }
 476                 if (repl) {
 477                         krb5_free_ap_rep_enc_part(gensec_krb5_state->smb_krb5_context->krb5_context, repl);
 478                 }
 479                 return nt_status;
 480         }
 481
 482         case GENSEC_KRB5_SERVER_START:
 483         {
 484                 DATA_BLOB unwrapped_in;
 485                 DATA_BLOB unwrapped_out = data_blob(NULL, 0);
 486                 krb5_data inbuf, outbuf;
 487                 uint8_t tok_id[2];
 488                 struct keytab_container *keytab;
 489                 krb5_principal server_in_keytab;
 490                 const char *error_string;
 491                 enum credentials_obtained obtained;
 492
 493                 if (!in.data) {
 494                         return NT_STATUS_INVALID_PARAMETER;
 495                 }
 496
 497                 /* Grab the keytab, however generated */
 498                 ret = cli_credentials_get_keytab(gensec_get_credentials(gensec_security),
 499                                                  gensec_security->settings->lp_ctx, &keytab);
 500                 if (ret) {
 501                         return NT_STATUS_CANT_ACCESS_DOMAIN_INFO;
 502                 }
 503
 504                 /* This ensures we lookup the correct entry in that
 505                  * keytab.  A NULL principal is acceptable, and means
 506                  * that the krb5 libs should search the keytab at
 507                  * accept time for any matching key */
 508                 ret = principal_from_credentials(out_mem_ctx, gensec_get_credentials(gensec_security),
 509                                                  gensec_krb5_state->smb_krb5_context,
 510                                                  &server_in_keytab, &obtained, &error_string);
 511
 512                 if (ret) {
 513                         DEBUG(2,("Failed to make credentials from principal: %s\n", error_string));
 514                         return NT_STATUS_CANT_ACCESS_DOMAIN_INFO;
 515                 }
 516
 517                 /* Parse the GSSAPI wrapping, if it's there... (win2k3 allows it to be omited) */
 518                 if (gensec_krb5_state->gssapi
 519                     && gensec_gssapi_parse_krb5_wrap(out_mem_ctx, &in, &unwrapped_in, tok_id)) {
 520                         inbuf.data = unwrapped_in.data;
 521                         inbuf.length = unwrapped_in.length;
 522                 } else {
 523                         inbuf.data = in.data;
 524                         inbuf.length = in.length;
 525                 }
 526
 527                 ret = smb_rd_req_return_stuff(gensec_krb5_state->smb_krb5_context->krb5_context,
 528                                               &gensec_krb5_state->auth_context,
 529                                               &inbuf, keytab->keytab, server_in_keytab,
 530                                               &outbuf,
 531                                               &gensec_krb5_state->ticket,
 532                                               &gensec_krb5_state->keyblock);
 533
 534                 if (ret) {
 535                         return NT_STATUS_LOGON_FAILURE;
 536                 }
 537                 unwrapped_out.data = (uint8_t *)outbuf.data;
 538                 unwrapped_out.length = outbuf.length;
 539                 gensec_krb5_state->state_position = GENSEC_KRB5_DONE;
 540                 /* wrap that up in a nice GSS-API wrapping */
 541                 if (gensec_krb5_state->gssapi) {
 542                         *out = gensec_gssapi_gen_krb5_wrap(out_mem_ctx, &unwrapped_out, TOK_ID_KRB_AP_REP);
 543                 } else {
 544                         *out = data_blob_talloc(out_mem_ctx, outbuf.data, outbuf.length);
 545                 }
 546                 krb5_data_free(&outbuf);
 547                 return NT_STATUS_OK;
 548         }
 549
 550         case GENSEC_KRB5_DONE:
 551         default:
 552                 /* Asking too many times... */
 553                 return NT_STATUS_INVALID_PARAMETER;
 554         }
 555 }
 556
 557 static NTSTATUS gensec_krb5_session_key(struct gensec_security *gensec_security,
 558                                         TALLOC_CTX *mem_ctx,
 559                                         DATA_BLOB *session_key)
 560 {
 561         struct gensec_krb5_state *gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
 562         krb5_context context = gensec_krb5_state->smb_krb5_context->krb5_context;
 563         krb5_auth_context auth_context = gensec_krb5_state->auth_context;
 564         krb5_keyblock *skey;
 565         krb5_error_code err = -1;
 566
 567         if (gensec_krb5_state->state_position != GENSEC_KRB5_DONE) {
 568                 return NT_STATUS_NO_USER_SESSION_KEY;
 569         }
 570
 571         switch (gensec_security->gensec_role) {
 572         case GENSEC_CLIENT:
 573                 err = krb5_auth_con_getlocalsubkey(context, auth_context, &skey);
 574                 break;
 575         case GENSEC_SERVER:
 576                 err = krb5_auth_con_getremotesubkey(context, auth_context, &skey);
 577                 break;
 578         }
 579         if (err == 0 && skey != NULL) {
 580                 DEBUG(10, ("Got KRB5 session key of length %d\n",
 581                            (int)KRB5_KEY_LENGTH(skey)));
 582                 *session_key = data_blob_talloc(mem_ctx,
 583                                                KRB5_KEY_DATA(skey), KRB5_KEY_LENGTH(skey));
 584                 dump_data_pw("KRB5 Session Key:\n", session_key->data, session_key->length);
 585
 586                 krb5_free_keyblock(context, skey);
 587                 return NT_STATUS_OK;
 588         } else {
 589                 DEBUG(10, ("KRB5 error getting session key %d\n", err));
 590                 return NT_STATUS_NO_USER_SESSION_KEY;
 591         }
 592 }
 593
 594 static NTSTATUS gensec_krb5_session_info(struct gensec_security *gensec_security,
 595                                          TALLOC_CTX *mem_ctx,
 596                                          struct auth_session_info **_session_info)
 597 {
 598         NTSTATUS nt_status = NT_STATUS_UNSUCCESSFUL;
 599         struct gensec_krb5_state *gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
 600         krb5_context context = gensec_krb5_state->smb_krb5_context->krb5_context;
 601         struct auth_session_info *session_info = NULL;
 602
 603         krb5_principal client_principal;
 604         char *principal_string;
 605
 606         DATA_BLOB pac_blob, *pac_blob_ptr = NULL;
 607         krb5_data pac_data;
 608
 609         krb5_error_code ret;
 610
 611         TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx);
 612         if (!tmp_ctx) {
 613                 return NT_STATUS_NO_MEMORY;
 614         }
 615
 616         ret = krb5_ticket_get_client(context, gensec_krb5_state->ticket, &client_principal);
 617         if (ret) {
 618                 DEBUG(5, ("krb5_ticket_get_client failed to get cleint principal: %s\n",
 619                           smb_get_krb5_error_message(context,
 620                                                      ret, tmp_ctx)));
 621                 talloc_free(tmp_ctx);
 622                 return NT_STATUS_NO_MEMORY;
 623         }
 624
 625         ret = krb5_unparse_name(gensec_krb5_state->smb_krb5_context->krb5_context,
 626                                 client_principal, &principal_string);
 627         if (ret) {
 628                 DEBUG(1, ("Unable to parse client principal: %s\n",
 629                           smb_get_krb5_error_message(context,
 630                                                      ret, tmp_ctx)));
 631                 krb5_free_principal(context, client_principal);
 632                 talloc_free(tmp_ctx);
 633                 return NT_STATUS_NO_MEMORY;
 634         }
 635
 636         ret = krb5_ticket_get_authorization_data_type(context, gensec_krb5_state->ticket,
 637                                                       KRB5_AUTHDATA_WIN2K_PAC,
 638                                                       &pac_data);
 639
 640         if (ret) {
 641                 /* NO pac */
 642                 DEBUG(5, ("krb5_ticket_get_authorization_data_type failed to find PAC: %s\n",
 643                           smb_get_krb5_error_message(context,
 644                                                      ret, tmp_ctx)));
 645         } else {
 646                 /* Found pac */
 647                 pac_blob = data_blob_talloc(tmp_ctx, pac_data.data, pac_data.length);
 648                 if (!pac_blob.data) {
 649                         free(principal_string);
 650                         krb5_free_principal(context, client_principal);
 651                         talloc_free(tmp_ctx);
 652                         return NT_STATUS_NO_MEMORY;
 653                 }
 654
 655                 /* decode and verify the pac */
 656                 nt_status = kerberos_decode_pac(gensec_krb5_state,
 657                                                 pac_blob,
 658                                                 gensec_krb5_state->smb_krb5_context->krb5_context,
 659                                                 NULL, gensec_krb5_state->keyblock,
 660                                                 client_principal,
 661                                                 gensec_krb5_state->ticket->ticket.authtime, NULL);
 662
 663                 if (!NT_STATUS_IS_OK(nt_status)) {
 664                         free(principal_string);
 665                         krb5_free_principal(context, client_principal);
 666                         talloc_free(tmp_ctx);
 667                         return nt_status;
 668                 }
 669
 670                 pac_blob_ptr = &pac_blob;
 671         }
 672
 673         nt_status = gensec_generate_session_info_pac(tmp_ctx,
 674                                                      gensec_security,
 675                                                      gensec_krb5_state->smb_krb5_context,
 676                                                      pac_blob_ptr, principal_string,
 677                                                      gensec_get_remote_address(gensec_security),
 678                                                      &session_info);
 679
 680         free(principal_string);
 681         krb5_free_principal(context, client_principal);
 682
 683         if (!NT_STATUS_IS_OK(nt_status)) {
 684                 talloc_free(tmp_ctx);
 685                 return nt_status;
 686         }
 687
 688         nt_status = gensec_krb5_session_key(gensec_security, session_info, &session_info->session_key);
 689
 690         if (!NT_STATUS_IS_OK(nt_status)) {
 691                 talloc_free(tmp_ctx);
 692                 return nt_status;
 693         }
 694
 695         *_session_info = talloc_steal(mem_ctx, session_info);
 696
 697         talloc_free(tmp_ctx);
 698         return NT_STATUS_OK;
 699 }
 700
 701 static NTSTATUS gensec_krb5_wrap(struct gensec_security *gensec_security,
 702                                    TALLOC_CTX *mem_ctx,
 703                                    const DATA_BLOB *in,
 704                                    DATA_BLOB *out)
 705 {
 706         struct gensec_krb5_state *gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
 707         krb5_context context = gensec_krb5_state->smb_krb5_context->krb5_context;
 708         krb5_auth_context auth_context = gensec_krb5_state->auth_context;
 709         krb5_error_code ret;
 710         krb5_data input, output;
 711         input.length = in->length;
 712         input.data = in->data;
 713
 714         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
 715                 ret = krb5_mk_priv(context, auth_context, &input, &output, NULL);
 716                 if (ret) {
 717                         DEBUG(1, ("krb5_mk_priv failed: %s\n",
 718                                   smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context,
 719                                                              ret, mem_ctx)));
 720                         return NT_STATUS_ACCESS_DENIED;
 721                 }
 722                 *out = data_blob_talloc(mem_ctx, output.data, output.length);
 723
 724                 krb5_data_free(&output);
 725         } else {
 726                 return NT_STATUS_ACCESS_DENIED;
 727         }
 728         return NT_STATUS_OK;
 729 }
 730
 731 static NTSTATUS gensec_krb5_unwrap(struct gensec_security *gensec_security,
 732                                      TALLOC_CTX *mem_ctx,
 733                                      const DATA_BLOB *in,
 734                                      DATA_BLOB *out)
 735 {
 736         struct gensec_krb5_state *gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
 737         krb5_context context = gensec_krb5_state->smb_krb5_context->krb5_context;
 738         krb5_auth_context auth_context = gensec_krb5_state->auth_context;
 739         krb5_error_code ret;
 740         krb5_data input, output;
 741         krb5_replay_data replay;
 742         input.length = in->length;
 743         input.data = in->data;
 744
 745         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
 746                 ret = krb5_rd_priv(context, auth_context, &input, &output, &replay);
 747                 if (ret) {
 748                         DEBUG(1, ("krb5_rd_priv failed: %s\n",
 749                                   smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context,
 750                                                              ret, mem_ctx)));
 751                         return NT_STATUS_ACCESS_DENIED;
 752                 }
 753                 *out = data_blob_talloc(mem_ctx, output.data, output.length);
 754
 755                 krb5_data_free(&output);
 756         } else {
 757                 return NT_STATUS_ACCESS_DENIED;
 758         }
 759         return NT_STATUS_OK;
 760 }
 761
 762 static bool gensec_krb5_have_feature(struct gensec_security *gensec_security,
 763                                      uint32_t feature)
 764 {
 765         struct gensec_krb5_state *gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
 766         if (feature & GENSEC_FEATURE_SESSION_KEY) {
 767                 return true;
 768         }
 769         if (!gensec_krb5_state->gssapi &&
 770             (feature & GENSEC_FEATURE_SEAL)) {
 771                 return true;
 772         }
 773
 774         return false;
 775 }
 776
 777 static const char *gensec_krb5_oids[] = {
 778         GENSEC_OID_KERBEROS5,
 779         GENSEC_OID_KERBEROS5_OLD,
 780         NULL
 781 };
 782
 783 static const struct gensec_security_ops gensec_fake_gssapi_krb5_security_ops = {
 784         .name           = "fake_gssapi_krb5",
 785         .auth_type      = DCERPC_AUTH_TYPE_KRB5,
 786         .oid            = gensec_krb5_oids,
 787         .client_start   = gensec_fake_gssapi_krb5_client_start,
 788         .server_start   = gensec_fake_gssapi_krb5_server_start,
 789         .update         = gensec_krb5_update,
 790         .magic          = gensec_magic_check_krb5_oid,
 791         .session_key    = gensec_krb5_session_key,
 792         .session_info   = gensec_krb5_session_info,
 793         .have_feature   = gensec_krb5_have_feature,
 794         .enabled        = false,
 795         .kerberos       = true,
 796         .priority       = GENSEC_KRB5
 797 };
 798
 799 static const struct gensec_security_ops gensec_krb5_security_ops = {
 800         .name           = "krb5",
 801         .client_start   = gensec_krb5_client_start,
 802         .server_start   = gensec_krb5_server_start,
 803         .update         = gensec_krb5_update,
 804         .session_key    = gensec_krb5_session_key,
 805         .session_info   = gensec_krb5_session_info,
 806         .have_feature   = gensec_krb5_have_feature,
 807         .wrap           = gensec_krb5_wrap,
 808         .unwrap         = gensec_krb5_unwrap,
 809         .enabled        = true,
 810         .kerberos       = true,
 811         .priority       = GENSEC_KRB5
 812 };
 813
 814 _PUBLIC_ NTSTATUS gensec_krb5_init(void)
 815 {
 816         NTSTATUS ret;
 817
 818         ret = gensec_register(&gensec_krb5_security_ops);
 819         if (!NT_STATUS_IS_OK(ret)) {
 820                 DEBUG(0,("Failed to register '%s' gensec backend!\n",
 821                         gensec_krb5_security_ops.name));
 822                 return ret;
 823         }
 824
 825         ret = gensec_register(&gensec_fake_gssapi_krb5_security_ops);
 826         if (!NT_STATUS_IS_OK(ret)) {
 827                 DEBUG(0,("Failed to register '%s' gensec backend!\n",
 828                         gensec_krb5_security_ops.name));
 829                 return ret;
 830         }
 831
 832         return ret;
 833 }