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