source4/auth/gensec/gensec_krb5.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    Kerberos backend for GENSEC
   5
   6    Copyright (C) Andrew Bartlett <abartlet@samba.org> 2004
   7    Copyright (C) Andrew Tridgell 2001
   8    Copyright (C) Luke Howard 2002-2003
   9    Copyright (C) Stefan Metzmacher 2004-2005
  10
  11    This program is free software; you can redistribute it and/or modify
  12    it under the terms of the GNU General Public License as published by
  13    the Free Software Foundation; either version 3 of the License, or
  14    (at your option) any later version.
  15
  16    This program is distributed in the hope that it will be useful,
  17    but WITHOUT ANY WARRANTY; without even the implied warranty of
  18    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19    GNU General Public License for more details.
  20
  21
  22    You should have received a copy of the GNU General Public License
  23    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  24 */
  25
  26 #include "includes.h"
  27 #include "system/kerberos.h"
  28 #include "auth/kerberos/kerberos.h"
  29 #include "librpc/gen_ndr/krb5pac.h"
  30 #include "auth/auth.h"
  31 #include "lib/ldb/include/ldb.h"
  32 #include "auth/auth_sam.h"
  33 #include "system/network.h"
  34 #include "lib/socket/socket.h"
  35 #include "librpc/rpc/dcerpc.h"
  36 #include "auth/credentials/credentials.h"
  37 #include "auth/credentials/credentials_krb5.h"
  38 #include "auth/gensec/gensec.h"
  39 #include "auth/gensec/gensec_proto.h"
  40 #include "param/param.h"
  41 #include "auth/session_proto.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 };
  61
  62 static int gensec_krb5_destroy(struct gensec_krb5_state *gensec_krb5_state)
  63 {
  64         if (!gensec_krb5_state->smb_krb5_context) {
  65                 /* We can't clean anything else up unless we started up this far */
  66                 return 0;
  67         }
  68         if (gensec_krb5_state->enc_ticket.length) {
  69                 kerberos_free_data_contents(gensec_krb5_state->smb_krb5_context->krb5_context,
  70                                             &gensec_krb5_state->enc_ticket);
  71         }
  72
  73         if (gensec_krb5_state->ticket) {
  74                 krb5_free_ticket(gensec_krb5_state->smb_krb5_context->krb5_context,
  75                                  gensec_krb5_state->ticket);
  76         }
  77
  78         /* ccache freed in a child destructor */
  79
  80         krb5_free_keyblock(gensec_krb5_state->smb_krb5_context->krb5_context,
  81                            gensec_krb5_state->keyblock);
  82
  83         if (gensec_krb5_state->auth_context) {
  84                 krb5_auth_con_free(gensec_krb5_state->smb_krb5_context->krb5_context,
  85                                    gensec_krb5_state->auth_context);
  86         }
  87
  88         return 0;
  89 }
  90
  91 static NTSTATUS gensec_krb5_start(struct gensec_security *gensec_security)
  92 {
  93         krb5_error_code ret;
  94         struct gensec_krb5_state *gensec_krb5_state;
  95         struct cli_credentials *creds;
  96         const struct socket_address *my_addr, *peer_addr;
  97         krb5_address my_krb5_addr, peer_krb5_addr;
  98
  99         creds = gensec_get_credentials(gensec_security);
 100         if (!creds) {
 101                 return NT_STATUS_INVALID_PARAMETER;
 102         }
 103
 104         gensec_krb5_state = talloc(gensec_security, struct gensec_krb5_state);
 105         if (!gensec_krb5_state) {
 106                 return NT_STATUS_NO_MEMORY;
 107         }
 108
 109         gensec_security->private_data = gensec_krb5_state;
 110         gensec_krb5_state->smb_krb5_context = NULL;
 111         gensec_krb5_state->auth_context = NULL;
 112         gensec_krb5_state->ticket = NULL;
 113         ZERO_STRUCT(gensec_krb5_state->enc_ticket);
 114         gensec_krb5_state->keyblock = NULL;
 115         gensec_krb5_state->session_key = data_blob(NULL, 0);
 116         gensec_krb5_state->pac = data_blob(NULL, 0);
 117         gensec_krb5_state->gssapi = false;
 118
 119         talloc_set_destructor(gensec_krb5_state, gensec_krb5_destroy);
 120
 121         if (cli_credentials_get_krb5_context(creds, gensec_security->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         my_addr = gensec_get_my_addr(gensec_security);
 147         if (my_addr && my_addr->sockaddr) {
 148                 ret = krb5_sockaddr2address(gensec_krb5_state->smb_krb5_context->krb5_context,
 149                                             my_addr->sockaddr, &my_krb5_addr);
 150                 if (ret) {
 151                         DEBUG(1,("gensec_krb5_start: krb5_sockaddr2address (local) failed (%s)\n",
 152                                  smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context,
 153                                                             ret, gensec_krb5_state)));
 154                         talloc_free(gensec_krb5_state);
 155                         return NT_STATUS_INTERNAL_ERROR;
 156                 }
 157         }
 158
 159         peer_addr = gensec_get_peer_addr(gensec_security);
 160         if (peer_addr && peer_addr->sockaddr) {
 161                 ret = krb5_sockaddr2address(gensec_krb5_state->smb_krb5_context->krb5_context,
 162                                             peer_addr->sockaddr, &peer_krb5_addr);
 163                 if (ret) {
 164                         DEBUG(1,("gensec_krb5_start: krb5_sockaddr2address (local) failed (%s)\n",
 165                                  smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context,
 166                                                             ret, gensec_krb5_state)));
 167                         talloc_free(gensec_krb5_state);
 168                         return NT_STATUS_INTERNAL_ERROR;
 169                 }
 170         }
 171
 172         ret = krb5_auth_con_setaddrs(gensec_krb5_state->smb_krb5_context->krb5_context,
 173                                      gensec_krb5_state->auth_context,
 174                                      my_addr ? &my_krb5_addr : NULL,
 175                                      peer_addr ? &peer_krb5_addr : NULL);
 176         if (ret) {
 177                 DEBUG(1,("gensec_krb5_start: krb5_auth_con_setaddrs failed (%s)\n",
 178                          smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context,
 179                                                     ret, gensec_krb5_state)));
 180                 talloc_free(gensec_krb5_state);
 181                 return NT_STATUS_INTERNAL_ERROR;
 182         }
 183
 184         return NT_STATUS_OK;
 185 }
 186
 187 static NTSTATUS gensec_krb5_server_start(struct gensec_security *gensec_security)
 188 {
 189         NTSTATUS nt_status;
 190         struct gensec_krb5_state *gensec_krb5_state;
 191
 192         nt_status = gensec_krb5_start(gensec_security);
 193         if (!NT_STATUS_IS_OK(nt_status)) {
 194                 return nt_status;
 195         }
 196
 197         gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
 198         gensec_krb5_state->state_position = GENSEC_KRB5_SERVER_START;
 199
 200         return NT_STATUS_OK;
 201 }
 202
 203 static NTSTATUS gensec_fake_gssapi_krb5_server_start(struct gensec_security *gensec_security)
 204 {
 205         NTSTATUS nt_status = gensec_krb5_server_start(gensec_security);
 206
 207         if (NT_STATUS_IS_OK(nt_status)) {
 208                 struct gensec_krb5_state *gensec_krb5_state;
 209                 gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
 210                 gensec_krb5_state->gssapi = true;
 211         }
 212         return nt_status;
 213 }
 214
 215 static NTSTATUS gensec_krb5_client_start(struct gensec_security *gensec_security)
 216 {
 217         struct gensec_krb5_state *gensec_krb5_state;
 218         krb5_error_code ret;
 219         NTSTATUS nt_status;
 220         struct ccache_container *ccache_container;
 221         const char *hostname;
 222         krb5_flags ap_req_options = AP_OPTS_USE_SUBKEY | AP_OPTS_MUTUAL_REQUIRED;
 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);
 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
 249         principal = gensec_get_target_principal(gensec_security);
 250
 251         ret = cli_credentials_get_ccache(gensec_get_credentials(gensec_security), gensec_security->lp_ctx, &ccache_container);
 252         switch (ret) {
 253         case 0:
 254                 break;
 255         case KRB5KDC_ERR_PREAUTH_FAILED:
 256                 return NT_STATUS_LOGON_FAILURE;
 257         case KRB5_KDC_UNREACH:
 258                 DEBUG(3, ("Cannot reach a KDC we require to contact %s\n", principal));
 259                 return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
 260         default:
 261                 DEBUG(1, ("gensec_krb5_start: Aquiring initiator credentials failed: %s\n", error_message(ret)));
 262                 return NT_STATUS_UNSUCCESSFUL;
 263         }
 264         in_data.length = 0;
 265
 266         if (principal && lp_client_use_spnego_principal(gensec_security->lp_ctx)) {
 267                 krb5_principal target_principal;
 268                 ret = krb5_parse_name(gensec_krb5_state->smb_krb5_context->krb5_context, principal,
 269                                       &target_principal);
 270                 if (ret == 0) {
 271                         ret = krb5_mk_req_exact(gensec_krb5_state->smb_krb5_context->krb5_context,
 272                                                 &gensec_krb5_state->auth_context,
 273                                                 ap_req_options,
 274                                                 target_principal,
 275                                                 &in_data, ccache_container->ccache,
 276                                                 &gensec_krb5_state->enc_ticket);
 277                         krb5_free_principal(gensec_krb5_state->smb_krb5_context->krb5_context,
 278                                             target_principal);
 279                 }
 280         } else {
 281                 ret = krb5_mk_req(gensec_krb5_state->smb_krb5_context->krb5_context,
 282                                   &gensec_krb5_state->auth_context,
 283                                   ap_req_options,
 284                                   gensec_get_target_service(gensec_security),
 285                                   hostname,
 286                                   &in_data, ccache_container->ccache,
 287                                   &gensec_krb5_state->enc_ticket);
 288         }
 289         switch (ret) {
 290         case 0:
 291                 return NT_STATUS_OK;
 292         case KRB5KDC_ERR_S_PRINCIPAL_UNKNOWN:
 293                 DEBUG(3, ("Server [%s] is not registered with our KDC: %s\n",
 294                           hostname, smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context, ret, gensec_krb5_state)));
 295                 return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
 296         case KRB5_KDC_UNREACH:
 297                 DEBUG(3, ("Cannot reach a KDC we require to contact host [%s]: %s\n",
 298                           hostname, smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context, ret, gensec_krb5_state)));
 299                 return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
 300         case KRB5KDC_ERR_PREAUTH_FAILED:
 301         case KRB5KRB_AP_ERR_TKT_EXPIRED:
 302         case KRB5_CC_END:
 303                 /* Too much clock skew - we will need to kinit to re-skew the clock */
 304         case KRB5KRB_AP_ERR_SKEW:
 305         case KRB5_KDCREP_SKEW:
 306         {
 307                 DEBUG(3, ("kerberos (mk_req) failed: %s\n",
 308                           smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context, ret, gensec_krb5_state)));
 309                 /*fall through*/
 310         }
 311
 312         /* just don't print a message for these really ordinary messages */
 313         case KRB5_FCC_NOFILE:
 314         case KRB5_CC_NOTFOUND:
 315         case ENOENT:
 316
 317                 return NT_STATUS_UNSUCCESSFUL;
 318                 break;
 319
 320         default:
 321                 DEBUG(0, ("kerberos: %s\n",
 322                           smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context, ret, gensec_krb5_state)));
 323                 return NT_STATUS_UNSUCCESSFUL;
 324         }
 325 }
 326
 327 static NTSTATUS gensec_fake_gssapi_krb5_client_start(struct gensec_security *gensec_security)
 328 {
 329         NTSTATUS nt_status = gensec_krb5_client_start(gensec_security);
 330
 331         if (NT_STATUS_IS_OK(nt_status)) {
 332                 struct gensec_krb5_state *gensec_krb5_state;
 333                 gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
 334                 gensec_krb5_state->gssapi = true;
 335         }
 336         return nt_status;
 337 }
 338
 339 /**
 340  * Check if the packet is one for this mechansim
 341  *
 342  * @param gensec_security GENSEC state
 343  * @param in The request, as a DATA_BLOB
 344  * @return Error, INVALID_PARAMETER if it's not a packet for us
 345  *                or NT_STATUS_OK if the packet is ok.
 346  */
 347
 348 static NTSTATUS gensec_fake_gssapi_krb5_magic(struct gensec_security *gensec_security,
 349                                   const DATA_BLOB *in)
 350 {
 351         if (gensec_gssapi_check_oid(in, GENSEC_OID_KERBEROS5)) {
 352                 return NT_STATUS_OK;
 353         } else {
 354                 return NT_STATUS_INVALID_PARAMETER;
 355         }
 356 }
 357
 358
 359 /**
 360  * Next state function for the Krb5 GENSEC mechanism
 361  *
 362  * @param gensec_krb5_state KRB5 State
 363  * @param out_mem_ctx The TALLOC_CTX for *out to be allocated on
 364  * @param in The request, as a DATA_BLOB
 365  * @param out The reply, as an talloc()ed DATA_BLOB, on *out_mem_ctx
 366  * @return Error, MORE_PROCESSING_REQUIRED if a reply is sent,
 367  *                or NT_STATUS_OK if the user is authenticated.
 368  */
 369
 370 static NTSTATUS gensec_krb5_update(struct gensec_security *gensec_security,
 371                                    TALLOC_CTX *out_mem_ctx,
 372                                    const DATA_BLOB in, DATA_BLOB *out)
 373 {
 374         struct gensec_krb5_state *gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
 375         krb5_error_code ret = 0;
 376         NTSTATUS nt_status;
 377
 378         switch (gensec_krb5_state->state_position) {
 379         case GENSEC_KRB5_CLIENT_START:
 380         {
 381                 DATA_BLOB unwrapped_out;
 382
 383                 if (gensec_krb5_state->gssapi) {
 384                         unwrapped_out = data_blob_talloc(out_mem_ctx, gensec_krb5_state->enc_ticket.data, gensec_krb5_state->enc_ticket.length);
 385
 386                         /* wrap that up in a nice GSS-API wrapping */
 387                         *out = gensec_gssapi_gen_krb5_wrap(out_mem_ctx, &unwrapped_out, TOK_ID_KRB_AP_REQ);
 388                 } else {
 389                         *out = data_blob_talloc(out_mem_ctx, gensec_krb5_state->enc_ticket.data, gensec_krb5_state->enc_ticket.length);
 390                 }
 391                 gensec_krb5_state->state_position = GENSEC_KRB5_CLIENT_MUTUAL_AUTH;
 392                 nt_status = NT_STATUS_MORE_PROCESSING_REQUIRED;
 393                 return nt_status;
 394         }
 395
 396         case GENSEC_KRB5_CLIENT_MUTUAL_AUTH:
 397         {
 398                 DATA_BLOB unwrapped_in;
 399                 krb5_data inbuf;
 400                 krb5_ap_rep_enc_part *repl = NULL;
 401                 uint8_t tok_id[2];
 402
 403                 if (gensec_krb5_state->gssapi) {
 404                         if (!gensec_gssapi_parse_krb5_wrap(out_mem_ctx, &in, &unwrapped_in, tok_id)) {
 405                                 DEBUG(1,("gensec_gssapi_parse_krb5_wrap(mutual authentication) failed to parse\n"));
 406                                 dump_data_pw("Mutual authentication message:\n", in.data, in.length);
 407                                 return NT_STATUS_INVALID_PARAMETER;
 408                         }
 409                 } else {
 410                         unwrapped_in = in;
 411                 }
 412                 /* TODO: check the tok_id */
 413
 414                 inbuf.data = unwrapped_in.data;
 415                 inbuf.length = unwrapped_in.length;
 416                 ret = krb5_rd_rep(gensec_krb5_state->smb_krb5_context->krb5_context,
 417                                   gensec_krb5_state->auth_context,
 418                                   &inbuf, &repl);
 419                 if (ret) {
 420                         DEBUG(1,("krb5_rd_rep (mutual authentication) failed (%s)\n",
 421                                  smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context, ret, out_mem_ctx)));
 422                         dump_data_pw("Mutual authentication message:\n", (uint8_t *)inbuf.data, inbuf.length);
 423                         nt_status = NT_STATUS_ACCESS_DENIED;
 424                 } else {
 425                         *out = data_blob(NULL, 0);
 426                         nt_status = NT_STATUS_OK;
 427                         gensec_krb5_state->state_position = GENSEC_KRB5_DONE;
 428                 }
 429                 if (repl) {
 430                         krb5_free_ap_rep_enc_part(gensec_krb5_state->smb_krb5_context->krb5_context, repl);
 431                 }
 432                 return nt_status;
 433         }
 434
 435         case GENSEC_KRB5_SERVER_START:
 436         {
 437                 DATA_BLOB unwrapped_in;
 438                 DATA_BLOB unwrapped_out = data_blob(NULL, 0);
 439                 krb5_data inbuf, outbuf;
 440                 uint8_t tok_id[2];
 441                 struct keytab_container *keytab;
 442                 krb5_principal server_in_keytab;
 443
 444                 if (!in.data) {
 445                         return NT_STATUS_INVALID_PARAMETER;
 446                 }
 447
 448                 /* Grab the keytab, however generated */
 449                 ret = cli_credentials_get_keytab(gensec_get_credentials(gensec_security), gensec_security->lp_ctx, &keytab);
 450                 if (ret) {
 451                         return NT_STATUS_CANT_ACCESS_DOMAIN_INFO;
 452                 }
 453
 454                 /* This ensures we lookup the correct entry in that keytab */
 455                 ret = principal_from_credentials(out_mem_ctx, gensec_get_credentials(gensec_security),
 456                                                  gensec_krb5_state->smb_krb5_context,
 457                                                  &server_in_keytab);
 458
 459                 if (ret) {
 460                         return NT_STATUS_CANT_ACCESS_DOMAIN_INFO;
 461                 }
 462
 463                 /* Parse the GSSAPI wrapping, if it's there... (win2k3 allows it to be omited) */
 464                 if (gensec_krb5_state->gssapi
 465                     && gensec_gssapi_parse_krb5_wrap(out_mem_ctx, &in, &unwrapped_in, tok_id)) {
 466                         inbuf.data = unwrapped_in.data;
 467                         inbuf.length = unwrapped_in.length;
 468                 } else {
 469                         inbuf.data = in.data;
 470                         inbuf.length = in.length;
 471                 }
 472
 473                 ret = smb_rd_req_return_stuff(gensec_krb5_state->smb_krb5_context->krb5_context,
 474                                               &gensec_krb5_state->auth_context,
 475                                               &inbuf, keytab->keytab, server_in_keytab,
 476                                               &outbuf,
 477                                               &gensec_krb5_state->ticket,
 478                                               &gensec_krb5_state->keyblock);
 479
 480                 if (ret) {
 481                         return NT_STATUS_LOGON_FAILURE;
 482                 }
 483                 unwrapped_out.data = (uint8_t *)outbuf.data;
 484                 unwrapped_out.length = outbuf.length;
 485                 gensec_krb5_state->state_position = GENSEC_KRB5_DONE;
 486                 /* wrap that up in a nice GSS-API wrapping */
 487                 if (gensec_krb5_state->gssapi) {
 488                         *out = gensec_gssapi_gen_krb5_wrap(out_mem_ctx, &unwrapped_out, TOK_ID_KRB_AP_REP);
 489                 } else {
 490                         *out = data_blob_talloc(out_mem_ctx, outbuf.data, outbuf.length);
 491                 }
 492                 krb5_data_free(&outbuf);
 493                 return NT_STATUS_OK;
 494         }
 495
 496         case GENSEC_KRB5_DONE:
 497         default:
 498                 /* Asking too many times... */
 499                 return NT_STATUS_INVALID_PARAMETER;
 500         }
 501 }
 502
 503 static NTSTATUS gensec_krb5_session_key(struct gensec_security *gensec_security,
 504                                         DATA_BLOB *session_key)
 505 {
 506         struct gensec_krb5_state *gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
 507         krb5_context context = gensec_krb5_state->smb_krb5_context->krb5_context;
 508         krb5_auth_context auth_context = gensec_krb5_state->auth_context;
 509         krb5_keyblock *skey;
 510         krb5_error_code err = -1;
 511
 512         if (gensec_krb5_state->session_key.data) {
 513                 *session_key = gensec_krb5_state->session_key;
 514                 return NT_STATUS_OK;
 515         }
 516
 517         switch (gensec_security->gensec_role) {
 518         case GENSEC_CLIENT:
 519                 err = krb5_auth_con_getlocalsubkey(context, auth_context, &skey);
 520                 break;
 521         case GENSEC_SERVER:
 522                 err = krb5_auth_con_getremotesubkey(context, auth_context, &skey);
 523                 break;
 524         }
 525         if (err == 0 && skey != NULL) {
 526                 DEBUG(10, ("Got KRB5 session key of length %d\n",
 527                            (int)KRB5_KEY_LENGTH(skey)));
 528                 gensec_krb5_state->session_key = data_blob_talloc(gensec_krb5_state,
 529                                                 KRB5_KEY_DATA(skey), KRB5_KEY_LENGTH(skey));
 530                 *session_key = gensec_krb5_state->session_key;
 531                 dump_data_pw("KRB5 Session Key:\n", session_key->data, session_key->length);
 532
 533                 krb5_free_keyblock(context, skey);
 534                 return NT_STATUS_OK;
 535         } else {
 536                 DEBUG(10, ("KRB5 error getting session key %d\n", err));
 537                 return NT_STATUS_NO_USER_SESSION_KEY;
 538         }
 539 }
 540
 541 static NTSTATUS gensec_krb5_session_info(struct gensec_security *gensec_security,
 542                                          struct auth_session_info **_session_info)
 543 {
 544         NTSTATUS nt_status = NT_STATUS_UNSUCCESSFUL;
 545         struct gensec_krb5_state *gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
 546         krb5_context context = gensec_krb5_state->smb_krb5_context->krb5_context;
 547         struct auth_serversupplied_info *server_info = NULL;
 548         struct auth_session_info *session_info = NULL;
 549         struct PAC_LOGON_INFO *logon_info;
 550
 551         krb5_principal client_principal;
 552         char *principal_string;
 553
 554         DATA_BLOB pac;
 555         krb5_data pac_data;
 556
 557         krb5_error_code ret;
 558
 559         TALLOC_CTX *mem_ctx = talloc_new(gensec_security);
 560         if (!mem_ctx) {
 561                 return NT_STATUS_NO_MEMORY;
 562         }
 563
 564         ret = krb5_ticket_get_client(context, gensec_krb5_state->ticket, &client_principal);
 565         if (ret) {
 566                 DEBUG(5, ("krb5_ticket_get_client failed to get cleint principal: %s\n",
 567                           smb_get_krb5_error_message(context,
 568                                                      ret, mem_ctx)));
 569                 talloc_free(mem_ctx);
 570                 return NT_STATUS_NO_MEMORY;
 571         }
 572
 573         ret = krb5_unparse_name(gensec_krb5_state->smb_krb5_context->krb5_context,
 574                                 client_principal, &principal_string);
 575         if (ret) {
 576                 DEBUG(1, ("Unable to parse client principal: %s\n",
 577                           smb_get_krb5_error_message(context,
 578                                                      ret, mem_ctx)));
 579                 talloc_free(mem_ctx);
 580                 return NT_STATUS_NO_MEMORY;
 581         }
 582
 583         ret = krb5_ticket_get_authorization_data_type(context, gensec_krb5_state->ticket,
 584                                                       KRB5_AUTHDATA_WIN2K_PAC,
 585                                                       &pac_data);
 586
 587         if (ret && lp_parm_bool(gensec_security->lp_ctx, NULL, "gensec", "require_pac", false)) {
 588                 DEBUG(1, ("Unable to find PAC in ticket from %s, failing to allow access: %s \n",
 589                           principal_string,
 590                           smb_get_krb5_error_message(context,
 591                                                      ret, mem_ctx)));
 592                 krb5_free_principal(context, client_principal);
 593                 free(principal_string);
 594                 return NT_STATUS_ACCESS_DENIED;
 595         } else if (ret) {
 596                 /* NO pac */
 597                 DEBUG(5, ("krb5_ticket_get_authorization_data_type failed to find PAC: %s\n",
 598                           smb_get_krb5_error_message(context,
 599                                                      ret, mem_ctx)));
 600                 nt_status = sam_get_server_info_principal(mem_ctx, gensec_security->lp_ctx, principal_string,
 601                                                           &server_info);
 602                 krb5_free_principal(context, client_principal);
 603                 free(principal_string);
 604
 605                 if (!NT_STATUS_IS_OK(nt_status)) {
 606                         talloc_free(mem_ctx);
 607                         return nt_status;
 608                 }
 609         } else {
 610                 /* Found pac */
 611                 union netr_Validation validation;
 612                 free(principal_string);
 613
 614                 pac = data_blob_talloc(mem_ctx, pac_data.data, pac_data.length);
 615                 if (!pac.data) {
 616                         krb5_free_principal(context, client_principal);
 617                         talloc_free(mem_ctx);
 618                         return NT_STATUS_NO_MEMORY;
 619                 }
 620
 621                 /* decode and verify the pac */
 622                 nt_status = kerberos_pac_logon_info(gensec_krb5_state,
 623                                                     lp_iconv_convenience(gensec_security->lp_ctx),
 624                                                     &logon_info, pac,
 625                                                     gensec_krb5_state->smb_krb5_context->krb5_context,
 626                                                     NULL, gensec_krb5_state->keyblock,
 627                                                     client_principal,
 628                                                     gensec_krb5_state->ticket->ticket.authtime, NULL);
 629                 krb5_free_principal(context, client_principal);
 630
 631                 if (!NT_STATUS_IS_OK(nt_status)) {
 632                         talloc_free(mem_ctx);
 633                         return nt_status;
 634                 }
 635
 636                 validation.sam3 = &logon_info->info3;
 637                 nt_status = make_server_info_netlogon_validation(mem_ctx,
 638                                                                  NULL,
 639                                                                  3, &validation,
 640                                                                  &server_info);
 641                 if (!NT_STATUS_IS_OK(nt_status)) {
 642                         talloc_free(mem_ctx);
 643                         return nt_status;
 644                 }
 645         }
 646
 647         /* references the server_info into the session_info */
 648         nt_status = auth_generate_session_info(mem_ctx, gensec_security->lp_ctx, server_info, &session_info);
 649
 650         if (!NT_STATUS_IS_OK(nt_status)) {
 651                 talloc_free(mem_ctx);
 652                 return nt_status;
 653         }
 654
 655         nt_status = gensec_krb5_session_key(gensec_security, &session_info->session_key);
 656
 657         if (!NT_STATUS_IS_OK(nt_status)) {
 658                 talloc_free(mem_ctx);
 659                 return nt_status;
 660         }
 661
 662         *_session_info = session_info;
 663
 664         talloc_steal(gensec_krb5_state, session_info);
 665         talloc_free(mem_ctx);
 666         return NT_STATUS_OK;
 667 }
 668
 669 static NTSTATUS gensec_krb5_wrap(struct gensec_security *gensec_security,
 670                                    TALLOC_CTX *mem_ctx,
 671                                    const DATA_BLOB *in,
 672                                    DATA_BLOB *out)
 673 {
 674         struct gensec_krb5_state *gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
 675         krb5_context context = gensec_krb5_state->smb_krb5_context->krb5_context;
 676         krb5_auth_context auth_context = gensec_krb5_state->auth_context;
 677         krb5_error_code ret;
 678         krb5_data input, output;
 679         input.length = in->length;
 680         input.data = in->data;
 681
 682         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
 683                 ret = krb5_mk_priv(context, auth_context, &input, &output, NULL);
 684                 if (ret) {
 685                         DEBUG(1, ("krb5_mk_priv failed: %s\n",
 686                                   smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context,
 687                                                              ret, mem_ctx)));
 688                         return NT_STATUS_ACCESS_DENIED;
 689                 }
 690                 *out = data_blob_talloc(mem_ctx, output.data, output.length);
 691
 692                 krb5_data_free(&output);
 693         } else {
 694                 return NT_STATUS_ACCESS_DENIED;
 695         }
 696         return NT_STATUS_OK;
 697 }
 698
 699 static NTSTATUS gensec_krb5_unwrap(struct gensec_security *gensec_security,
 700                                      TALLOC_CTX *mem_ctx,
 701                                      const DATA_BLOB *in,
 702                                      DATA_BLOB *out)
 703 {
 704         struct gensec_krb5_state *gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
 705         krb5_context context = gensec_krb5_state->smb_krb5_context->krb5_context;
 706         krb5_auth_context auth_context = gensec_krb5_state->auth_context;
 707         krb5_error_code ret;
 708         krb5_data input, output;
 709         krb5_replay_data replay;
 710         input.length = in->length;
 711         input.data = in->data;
 712
 713         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
 714                 ret = krb5_rd_priv(context, auth_context, &input, &output, &replay);
 715                 if (ret) {
 716                         DEBUG(1, ("krb5_rd_priv failed: %s\n",
 717                                   smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context,
 718                                                              ret, mem_ctx)));
 719                         return NT_STATUS_ACCESS_DENIED;
 720                 }
 721                 *out = data_blob_talloc(mem_ctx, output.data, output.length);
 722
 723                 krb5_data_free(&output);
 724         } else {
 725                 return NT_STATUS_ACCESS_DENIED;
 726         }
 727         return NT_STATUS_OK;
 728 }
 729
 730 static bool gensec_krb5_have_feature(struct gensec_security *gensec_security,
 731                                      uint32_t feature)
 732 {
 733         struct gensec_krb5_state *gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
 734         if (feature & GENSEC_FEATURE_SESSION_KEY) {
 735                 return true;
 736         }
 737         if (!gensec_krb5_state->gssapi &&
 738             (feature & GENSEC_FEATURE_SEAL)) {
 739                 return true;
 740         }
 741
 742         return false;
 743 }
 744
 745 static const char *gensec_krb5_oids[] = {
 746         GENSEC_OID_KERBEROS5,
 747         GENSEC_OID_KERBEROS5_OLD,
 748         NULL
 749 };
 750
 751 static const struct gensec_security_ops gensec_fake_gssapi_krb5_security_ops = {
 752         .name           = "fake_gssapi_krb5",
 753         .auth_type      = DCERPC_AUTH_TYPE_KRB5,
 754         .oid            = gensec_krb5_oids,
 755         .client_start   = gensec_fake_gssapi_krb5_client_start,
 756         .server_start   = gensec_fake_gssapi_krb5_server_start,
 757         .update         = gensec_krb5_update,
 758         .magic          = gensec_fake_gssapi_krb5_magic,
 759         .session_key    = gensec_krb5_session_key,
 760         .session_info   = gensec_krb5_session_info,
 761         .have_feature   = gensec_krb5_have_feature,
 762         .enabled        = false,
 763         .kerberos       = true,
 764         .priority       = GENSEC_KRB5
 765 };
 766
 767 static const struct gensec_security_ops gensec_krb5_security_ops = {
 768         .name           = "krb5",
 769         .client_start   = gensec_krb5_client_start,
 770         .server_start   = gensec_krb5_server_start,
 771         .update         = gensec_krb5_update,
 772         .session_key    = gensec_krb5_session_key,
 773         .session_info   = gensec_krb5_session_info,
 774         .have_feature   = gensec_krb5_have_feature,
 775         .wrap           = gensec_krb5_wrap,
 776         .unwrap         = gensec_krb5_unwrap,
 777         .enabled        = true,
 778         .kerberos       = true,
 779         .priority       = GENSEC_KRB5
 780 };
 781
 782 _PUBLIC_ NTSTATUS gensec_krb5_init(void)
 783 {
 784         NTSTATUS ret;
 785
 786         auth_init();
 787
 788         ret = gensec_register(&gensec_krb5_security_ops);
 789         if (!NT_STATUS_IS_OK(ret)) {
 790                 DEBUG(0,("Failed to register '%s' gensec backend!\n",
 791                         gensec_krb5_security_ops.name));
 792                 return ret;
 793         }
 794
 795         ret = gensec_register(&gensec_fake_gssapi_krb5_security_ops);
 796         if (!NT_STATUS_IS_OK(ret)) {
 797                 DEBUG(0,("Failed to register '%s' gensec backend!\n",
 798                         gensec_krb5_security_ops.name));
 799                 return ret;
 800         }
 801
 802         return ret;
 803 }