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 "param/param.h"
  39 #include "auth/auth_sam_reply.h"
  40 #include "lib/util/util_net.h"
  41
  42 enum GENSEC_KRB5_STATE {
  43         GENSEC_KRB5_SERVER_START,
  44         GENSEC_KRB5_CLIENT_START,
  45         GENSEC_KRB5_CLIENT_MUTUAL_AUTH,
  46         GENSEC_KRB5_DONE
  47 };
  48
  49 struct gensec_krb5_state {
  50         DATA_BLOB session_key;
  51         DATA_BLOB pac;
  52         enum GENSEC_KRB5_STATE state_position;
  53         struct smb_krb5_context *smb_krb5_context;
  54         krb5_auth_context auth_context;
  55         krb5_data enc_ticket;
  56         krb5_keyblock *keyblock;
  57         krb5_ticket *ticket;
  58         bool gssapi;
  59         krb5_flags ap_req_options;
  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, bool gssapi)
  92 {
  93         krb5_error_code ret;
  94         struct gensec_krb5_state *gensec_krb5_state;
  95         struct cli_credentials *creds;
  96         const struct tsocket_address *tlocal_addr, *tremote_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 = gssapi;
 118
 119         talloc_set_destructor(gensec_krb5_state, gensec_krb5_destroy);
 120
 121         if (cli_credentials_get_krb5_context(creds,
 122                                              gensec_security->event_ctx,
 123                                              gensec_security->settings->lp_ctx, &gensec_krb5_state->smb_krb5_context)) {
 124                 talloc_free(gensec_krb5_state);
 125                 return NT_STATUS_INTERNAL_ERROR;
 126         }
 127
 128         ret = krb5_auth_con_init(gensec_krb5_state->smb_krb5_context->krb5_context, &gensec_krb5_state->auth_context);
 129         if (ret) {
 130                 DEBUG(1,("gensec_krb5_start: krb5_auth_con_init failed (%s)\n",
 131                          smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context,
 132                                                     ret, gensec_krb5_state)));
 133                 talloc_free(gensec_krb5_state);
 134                 return NT_STATUS_INTERNAL_ERROR;
 135         }
 136
 137         ret = krb5_auth_con_setflags(gensec_krb5_state->smb_krb5_context->krb5_context,
 138                                      gensec_krb5_state->auth_context,
 139                                      KRB5_AUTH_CONTEXT_DO_SEQUENCE);
 140         if (ret) {
 141                 DEBUG(1,("gensec_krb5_start: krb5_auth_con_setflags failed (%s)\n",
 142                          smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context,
 143                                                     ret, gensec_krb5_state)));
 144                 talloc_free(gensec_krb5_state);
 145                 return NT_STATUS_INTERNAL_ERROR;
 146         }
 147
 148         tlocal_addr = gensec_get_local_address(gensec_security);
 149         if (tlocal_addr) {
 150                 ssize_t socklen;
 151                 struct sockaddr_storage ss;
 152
 153                 socklen = tsocket_address_bsd_sockaddr(tlocal_addr,
 154                                 (struct sockaddr *) &ss,
 155                                 sizeof(struct sockaddr_storage));
 156                 if (socklen < 0) {
 157                         return NT_STATUS_INTERNAL_ERROR;
 158                 }
 159                 ret = krb5_sockaddr2address(gensec_krb5_state->smb_krb5_context->krb5_context,
 160                                 (const struct sockaddr *) &ss, &my_krb5_addr);
 161                 if (ret) {
 162                         DEBUG(1,("gensec_krb5_start: krb5_sockaddr2address (local) failed (%s)\n",
 163                                  smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context,
 164                                                             ret, gensec_krb5_state)));
 165                         talloc_free(gensec_krb5_state);
 166                         return NT_STATUS_INTERNAL_ERROR;
 167                 }
 168         }
 169
 170         tremote_addr = gensec_get_remote_address(gensec_security);
 171         if (tremote_addr) {
 172                 ssize_t socklen;
 173                 struct sockaddr_storage ss;
 174
 175                 socklen = tsocket_address_bsd_sockaddr(tremote_addr,
 176                                 (struct sockaddr *) &ss,
 177                                 sizeof(struct sockaddr_storage));
 178                 if (socklen < 0) {
 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         struct gensec_krb5_state *gensec_krb5_state;
 236         krb5_error_code ret;
 237         NTSTATUS nt_status;
 238         struct ccache_container *ccache_container;
 239         const char *hostname;
 240         const char *error_string;
 241         const char *principal;
 242         krb5_data in_data;
 243
 244         hostname = gensec_get_target_hostname(gensec_security);
 245         if (!hostname) {
 246                 DEBUG(1, ("Could not determine hostname for target computer, cannot use kerberos\n"));
 247                 return NT_STATUS_INVALID_PARAMETER;
 248         }
 249         if (is_ipaddress(hostname)) {
 250                 DEBUG(2, ("Cannot do krb5 to an IP address"));
 251                 return NT_STATUS_INVALID_PARAMETER;
 252         }
 253         if (strcmp(hostname, "localhost") == 0) {
 254                 DEBUG(2, ("krb5 to 'localhost' does not make sense"));
 255                 return NT_STATUS_INVALID_PARAMETER;
 256         }
 257
 258         nt_status = gensec_krb5_start(gensec_security, gssapi);
 259         if (!NT_STATUS_IS_OK(nt_status)) {
 260                 return nt_status;
 261         }
 262
 263         gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
 264         gensec_krb5_state->state_position = GENSEC_KRB5_CLIENT_START;
 265         gensec_krb5_state->ap_req_options = AP_OPTS_USE_SUBKEY;
 266
 267         if (gensec_krb5_state->gssapi) {
 268                 /* The Fake GSSAPI modal emulates Samba3, which does not do mutual authentication */
 269                 if (gensec_setting_bool(gensec_security->settings, "gensec_fake_gssapi_krb5", "mutual", false)) {
 270                         gensec_krb5_state->ap_req_options |= AP_OPTS_MUTUAL_REQUIRED;
 271                 }
 272         } else {
 273                 /* The wrapping for KPASSWD (a user of the raw KRB5 API) should be mutually authenticated */
 274                 if (gensec_setting_bool(gensec_security->settings, "gensec_krb5", "mutual", true)) {
 275                         gensec_krb5_state->ap_req_options |= AP_OPTS_MUTUAL_REQUIRED;
 276                 }
 277         }
 278
 279         principal = gensec_get_target_principal(gensec_security);
 280
 281         ret = cli_credentials_get_ccache(gensec_get_credentials(gensec_security),
 282                                          gensec_security->event_ctx,
 283                                          gensec_security->settings->lp_ctx, &ccache_container, &error_string);
 284         switch (ret) {
 285         case 0:
 286                 break;
 287         case KRB5KDC_ERR_PREAUTH_FAILED:
 288                 return NT_STATUS_LOGON_FAILURE;
 289         case KRB5_KDC_UNREACH:
 290                 DEBUG(3, ("Cannot reach a KDC we require to contact %s: %s\n", principal, error_string));
 291                 return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
 292         case KRB5_CC_NOTFOUND:
 293         case KRB5_CC_END:
 294                 DEBUG(3, ("Error preparing credentials we require to contact %s : %s\n", principal, error_string));
 295                 return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
 296         default:
 297                 DEBUG(1, ("gensec_krb5_start: Aquiring initiator credentials failed: %s\n", error_string));
 298                 return NT_STATUS_UNSUCCESSFUL;
 299         }
 300         in_data.length = 0;
 301
 302         if (principal) {
 303                 krb5_principal target_principal;
 304                 ret = krb5_parse_name(gensec_krb5_state->smb_krb5_context->krb5_context, principal,
 305                                       &target_principal);
 306                 if (ret == 0) {
 307                         ret = krb5_mk_req_exact(gensec_krb5_state->smb_krb5_context->krb5_context,
 308                                                 &gensec_krb5_state->auth_context,
 309                                                 gensec_krb5_state->ap_req_options,
 310                                                 target_principal,
 311                                                 &in_data, ccache_container->ccache,
 312                                                 &gensec_krb5_state->enc_ticket);
 313                         krb5_free_principal(gensec_krb5_state->smb_krb5_context->krb5_context,
 314                                             target_principal);
 315                 }
 316         } else {
 317                 ret = krb5_mk_req(gensec_krb5_state->smb_krb5_context->krb5_context,
 318                                   &gensec_krb5_state->auth_context,
 319                                   gensec_krb5_state->ap_req_options,
 320                                   gensec_get_target_service(gensec_security),
 321                                   hostname,
 322                                   &in_data, ccache_container->ccache,
 323                                   &gensec_krb5_state->enc_ticket);
 324         }
 325         switch (ret) {
 326         case 0:
 327                 return NT_STATUS_OK;
 328         case KRB5KDC_ERR_S_PRINCIPAL_UNKNOWN:
 329                 DEBUG(3, ("Server [%s] is not registered with our KDC: %s\n",
 330                           hostname, smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context, ret, gensec_krb5_state)));
 331                 return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
 332         case KRB5_KDC_UNREACH:
 333                 DEBUG(3, ("Cannot reach a KDC we require to contact host [%s]: %s\n",
 334                           hostname, smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context, ret, gensec_krb5_state)));
 335                 return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
 336         case KRB5KDC_ERR_PREAUTH_FAILED:
 337         case KRB5KRB_AP_ERR_TKT_EXPIRED:
 338         case KRB5_CC_END:
 339                 /* Too much clock skew - we will need to kinit to re-skew the clock */
 340         case KRB5KRB_AP_ERR_SKEW:
 341         case KRB5_KDCREP_SKEW:
 342         {
 343                 DEBUG(3, ("kerberos (mk_req) failed: %s\n",
 344                           smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context, ret, gensec_krb5_state)));
 345                 /*fall through*/
 346         }
 347
 348         /* just don't print a message for these really ordinary messages */
 349         case KRB5_FCC_NOFILE:
 350         case KRB5_CC_NOTFOUND:
 351         case ENOENT:
 352
 353                 return NT_STATUS_UNSUCCESSFUL;
 354                 break;
 355
 356         default:
 357                 DEBUG(0, ("kerberos: %s\n",
 358                           smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context, ret, gensec_krb5_state)));
 359                 return NT_STATUS_UNSUCCESSFUL;
 360         }
 361 }
 362
 363 static NTSTATUS gensec_krb5_client_start(struct gensec_security *gensec_security)
 364 {
 365         return gensec_krb5_common_client_start(gensec_security, false);
 366 }
 367
 368 static NTSTATUS gensec_fake_gssapi_krb5_client_start(struct gensec_security *gensec_security)
 369 {
 370         return gensec_krb5_common_client_start(gensec_security, true);
 371 }
 372
 373 /**
 374  * Check if the packet is one for this mechansim
 375  *
 376  * @param gensec_security GENSEC state
 377  * @param in The request, as a DATA_BLOB
 378  * @return Error, INVALID_PARAMETER if it's not a packet for us
 379  *                or NT_STATUS_OK if the packet is ok.
 380  */
 381
 382 static NTSTATUS gensec_fake_gssapi_krb5_magic(struct gensec_security *gensec_security,
 383                                   const DATA_BLOB *in)
 384 {
 385         if (gensec_gssapi_check_oid(in, GENSEC_OID_KERBEROS5)) {
 386                 return NT_STATUS_OK;
 387         } else {
 388                 return NT_STATUS_INVALID_PARAMETER;
 389         }
 390 }
 391
 392
 393 /**
 394  * Next state function for the Krb5 GENSEC mechanism
 395  *
 396  * @param gensec_krb5_state KRB5 State
 397  * @param out_mem_ctx The TALLOC_CTX for *out to be allocated on
 398  * @param in The request, as a DATA_BLOB
 399  * @param out The reply, as an talloc()ed DATA_BLOB, on *out_mem_ctx
 400  * @return Error, MORE_PROCESSING_REQUIRED if a reply is sent,
 401  *                or NT_STATUS_OK if the user is authenticated.
 402  */
 403
 404 static NTSTATUS gensec_krb5_update(struct gensec_security *gensec_security,
 405                                    TALLOC_CTX *out_mem_ctx,
 406                                    const DATA_BLOB in, DATA_BLOB *out)
 407 {
 408         struct gensec_krb5_state *gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
 409         krb5_error_code ret = 0;
 410         NTSTATUS nt_status;
 411
 412         switch (gensec_krb5_state->state_position) {
 413         case GENSEC_KRB5_CLIENT_START:
 414         {
 415                 DATA_BLOB unwrapped_out;
 416
 417                 if (gensec_krb5_state->gssapi) {
 418                         unwrapped_out = data_blob_talloc(out_mem_ctx, gensec_krb5_state->enc_ticket.data, gensec_krb5_state->enc_ticket.length);
 419
 420                         /* wrap that up in a nice GSS-API wrapping */
 421                         *out = gensec_gssapi_gen_krb5_wrap(out_mem_ctx, &unwrapped_out, TOK_ID_KRB_AP_REQ);
 422                 } else {
 423                         *out = data_blob_talloc(out_mem_ctx, gensec_krb5_state->enc_ticket.data, gensec_krb5_state->enc_ticket.length);
 424                 }
 425                 if (gensec_krb5_state->ap_req_options & AP_OPTS_MUTUAL_REQUIRED) {
 426                         gensec_krb5_state->state_position = GENSEC_KRB5_CLIENT_MUTUAL_AUTH;
 427                         nt_status = NT_STATUS_MORE_PROCESSING_REQUIRED;
 428                 } else {
 429                         gensec_krb5_state->state_position = GENSEC_KRB5_DONE;
 430                         nt_status = NT_STATUS_OK;
 431                 }
 432                 return nt_status;
 433         }
 434
 435         case GENSEC_KRB5_CLIENT_MUTUAL_AUTH:
 436         {
 437                 DATA_BLOB unwrapped_in;
 438                 krb5_data inbuf;
 439                 krb5_ap_rep_enc_part *repl = NULL;
 440                 uint8_t tok_id[2];
 441
 442                 if (gensec_krb5_state->gssapi) {
 443                         if (!gensec_gssapi_parse_krb5_wrap(out_mem_ctx, &in, &unwrapped_in, tok_id)) {
 444                                 DEBUG(1,("gensec_gssapi_parse_krb5_wrap(mutual authentication) failed to parse\n"));
 445                                 dump_data_pw("Mutual authentication message:\n", in.data, in.length);
 446                                 return NT_STATUS_INVALID_PARAMETER;
 447                         }
 448                 } else {
 449                         unwrapped_in = in;
 450                 }
 451                 /* TODO: check the tok_id */
 452
 453                 inbuf.data = unwrapped_in.data;
 454                 inbuf.length = unwrapped_in.length;
 455                 ret = krb5_rd_rep(gensec_krb5_state->smb_krb5_context->krb5_context,
 456                                   gensec_krb5_state->auth_context,
 457                                   &inbuf, &repl);
 458                 if (ret) {
 459                         DEBUG(1,("krb5_rd_rep (mutual authentication) failed (%s)\n",
 460                                  smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context, ret, out_mem_ctx)));
 461                         dump_data_pw("Mutual authentication message:\n", (uint8_t *)inbuf.data, inbuf.length);
 462                         nt_status = NT_STATUS_ACCESS_DENIED;
 463                 } else {
 464                         *out = data_blob(NULL, 0);
 465                         nt_status = NT_STATUS_OK;
 466                         gensec_krb5_state->state_position = GENSEC_KRB5_DONE;
 467                 }
 468                 if (repl) {
 469                         krb5_free_ap_rep_enc_part(gensec_krb5_state->smb_krb5_context->krb5_context, repl);
 470                 }
 471                 return nt_status;
 472         }
 473
 474         case GENSEC_KRB5_SERVER_START:
 475         {
 476                 DATA_BLOB unwrapped_in;
 477                 DATA_BLOB unwrapped_out = data_blob(NULL, 0);
 478                 krb5_data inbuf, outbuf;
 479                 uint8_t tok_id[2];
 480                 struct keytab_container *keytab;
 481                 krb5_principal server_in_keytab;
 482                 const char *error_string;
 483                 enum credentials_obtained obtained;
 484
 485                 if (!in.data) {
 486                         return NT_STATUS_INVALID_PARAMETER;
 487                 }
 488
 489                 /* Grab the keytab, however generated */
 490                 ret = cli_credentials_get_keytab(gensec_get_credentials(gensec_security),
 491                                                  gensec_security->event_ctx,
 492                                                  gensec_security->settings->lp_ctx, &keytab);
 493                 if (ret) {
 494                         return NT_STATUS_CANT_ACCESS_DOMAIN_INFO;
 495                 }
 496
 497                 /* This ensures we lookup the correct entry in that keytab */
 498                 ret = principal_from_credentials(out_mem_ctx, gensec_get_credentials(gensec_security),
 499                                                  gensec_krb5_state->smb_krb5_context,
 500                                                  &server_in_keytab, &obtained, &error_string);
 501
 502                 if (ret) {
 503                         DEBUG(2,("Failed to make credentials from principal: %s\n", error_string));
 504                         return NT_STATUS_CANT_ACCESS_DOMAIN_INFO;
 505                 }
 506
 507                 /* Parse the GSSAPI wrapping, if it's there... (win2k3 allows it to be omited) */
 508                 if (gensec_krb5_state->gssapi
 509                     && gensec_gssapi_parse_krb5_wrap(out_mem_ctx, &in, &unwrapped_in, tok_id)) {
 510                         inbuf.data = unwrapped_in.data;
 511                         inbuf.length = unwrapped_in.length;
 512                 } else {
 513                         inbuf.data = in.data;
 514                         inbuf.length = in.length;
 515                 }
 516
 517                 ret = smb_rd_req_return_stuff(gensec_krb5_state->smb_krb5_context->krb5_context,
 518                                               &gensec_krb5_state->auth_context,
 519                                               &inbuf, keytab->keytab, server_in_keytab,
 520                                               &outbuf,
 521                                               &gensec_krb5_state->ticket,
 522                                               &gensec_krb5_state->keyblock);
 523
 524                 if (ret) {
 525                         return NT_STATUS_LOGON_FAILURE;
 526                 }
 527                 unwrapped_out.data = (uint8_t *)outbuf.data;
 528                 unwrapped_out.length = outbuf.length;
 529                 gensec_krb5_state->state_position = GENSEC_KRB5_DONE;
 530                 /* wrap that up in a nice GSS-API wrapping */
 531                 if (gensec_krb5_state->gssapi) {
 532                         *out = gensec_gssapi_gen_krb5_wrap(out_mem_ctx, &unwrapped_out, TOK_ID_KRB_AP_REP);
 533                 } else {
 534                         *out = data_blob_talloc(out_mem_ctx, outbuf.data, outbuf.length);
 535                 }
 536                 krb5_data_free(&outbuf);
 537                 return NT_STATUS_OK;
 538         }
 539
 540         case GENSEC_KRB5_DONE:
 541         default:
 542                 /* Asking too many times... */
 543                 return NT_STATUS_INVALID_PARAMETER;
 544         }
 545 }
 546
 547 static NTSTATUS gensec_krb5_session_key(struct gensec_security *gensec_security,
 548                                         DATA_BLOB *session_key)
 549 {
 550         struct gensec_krb5_state *gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
 551         krb5_context context = gensec_krb5_state->smb_krb5_context->krb5_context;
 552         krb5_auth_context auth_context = gensec_krb5_state->auth_context;
 553         krb5_keyblock *skey;
 554         krb5_error_code err = -1;
 555
 556         if (gensec_krb5_state->state_position != GENSEC_KRB5_DONE) {
 557                 return NT_STATUS_NO_USER_SESSION_KEY;
 558         }
 559
 560         if (gensec_krb5_state->session_key.data) {
 561                 *session_key = gensec_krb5_state->session_key;
 562                 return NT_STATUS_OK;
 563         }
 564
 565         switch (gensec_security->gensec_role) {
 566         case GENSEC_CLIENT:
 567                 err = krb5_auth_con_getlocalsubkey(context, auth_context, &skey);
 568                 break;
 569         case GENSEC_SERVER:
 570                 err = krb5_auth_con_getremotesubkey(context, auth_context, &skey);
 571                 break;
 572         }
 573         if (err == 0 && skey != NULL) {
 574                 DEBUG(10, ("Got KRB5 session key of length %d\n",
 575                            (int)KRB5_KEY_LENGTH(skey)));
 576                 gensec_krb5_state->session_key = data_blob_talloc(gensec_krb5_state,
 577                                                 KRB5_KEY_DATA(skey), KRB5_KEY_LENGTH(skey));
 578                 *session_key = gensec_krb5_state->session_key;
 579                 dump_data_pw("KRB5 Session Key:\n", session_key->data, session_key->length);
 580
 581                 krb5_free_keyblock(context, skey);
 582                 return NT_STATUS_OK;
 583         } else {
 584                 DEBUG(10, ("KRB5 error getting session key %d\n", err));
 585                 return NT_STATUS_NO_USER_SESSION_KEY;
 586         }
 587 }
 588
 589 static NTSTATUS gensec_krb5_session_info(struct gensec_security *gensec_security,
 590                                          struct auth_session_info **_session_info)
 591 {
 592         NTSTATUS nt_status = NT_STATUS_UNSUCCESSFUL;
 593         struct gensec_krb5_state *gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
 594         krb5_context context = gensec_krb5_state->smb_krb5_context->krb5_context;
 595         struct auth_serversupplied_info *server_info = NULL;
 596         struct auth_session_info *session_info = NULL;
 597         struct PAC_LOGON_INFO *logon_info;
 598
 599         krb5_principal client_principal;
 600         char *principal_string;
 601
 602         DATA_BLOB pac;
 603         krb5_data pac_data;
 604
 605         krb5_error_code ret;
 606
 607         TALLOC_CTX *mem_ctx = talloc_new(gensec_security);
 608         if (!mem_ctx) {
 609                 return NT_STATUS_NO_MEMORY;
 610         }
 611
 612         ret = krb5_ticket_get_client(context, gensec_krb5_state->ticket, &client_principal);
 613         if (ret) {
 614                 DEBUG(5, ("krb5_ticket_get_client failed to get cleint principal: %s\n",
 615                           smb_get_krb5_error_message(context,
 616                                                      ret, mem_ctx)));
 617                 talloc_free(mem_ctx);
 618                 return NT_STATUS_NO_MEMORY;
 619         }
 620
 621         ret = krb5_unparse_name(gensec_krb5_state->smb_krb5_context->krb5_context,
 622                                 client_principal, &principal_string);
 623         if (ret) {
 624                 DEBUG(1, ("Unable to parse client principal: %s\n",
 625                           smb_get_krb5_error_message(context,
 626                                                      ret, mem_ctx)));
 627                 talloc_free(mem_ctx);
 628                 return NT_STATUS_NO_MEMORY;
 629         }
 630
 631         ret = krb5_ticket_get_authorization_data_type(context, gensec_krb5_state->ticket,
 632                                                       KRB5_AUTHDATA_WIN2K_PAC,
 633                                                       &pac_data);
 634
 635         if (ret && gensec_setting_bool(gensec_security->settings, "gensec", "require_pac", false)) {
 636                 DEBUG(1, ("Unable to find PAC in ticket from %s, failing to allow access: %s \n",
 637                           principal_string,
 638                           smb_get_krb5_error_message(context,
 639                                                      ret, mem_ctx)));
 640                 krb5_free_principal(context, client_principal);
 641                 free(principal_string);
 642                 return NT_STATUS_ACCESS_DENIED;
 643         } else if (ret) {
 644                 /* NO pac */
 645                 DEBUG(5, ("krb5_ticket_get_authorization_data_type failed to find PAC: %s\n",
 646                           smb_get_krb5_error_message(context,
 647                                                      ret, mem_ctx)));
 648                 if (gensec_security->auth_context &&
 649                     !gensec_setting_bool(gensec_security->settings, "gensec", "require_pac", false)) {
 650                         DEBUG(1, ("Unable to find PAC for %s, resorting to local user lookup: %s",
 651                                   principal_string, smb_get_krb5_error_message(context,
 652                                                      ret, mem_ctx)));
 653                         nt_status = gensec_security->auth_context->get_server_info_principal(mem_ctx,
 654                                                                                              gensec_security->auth_context,
 655                                                                                              principal_string,
 656                                                                                              &server_info);
 657                         if (!NT_STATUS_IS_OK(nt_status)) {
 658                                 talloc_free(mem_ctx);
 659                                 return nt_status;
 660                         }
 661                 } else {
 662                         DEBUG(1, ("Unable to find PAC in ticket from %s, failing to allow access\n",
 663                                   principal_string));
 664                         return NT_STATUS_ACCESS_DENIED;
 665                 }
 666
 667                 krb5_free_principal(context, client_principal);
 668                 free(principal_string);
 669
 670                 if (!NT_STATUS_IS_OK(nt_status)) {
 671                         talloc_free(mem_ctx);
 672                         return nt_status;
 673                 }
 674         } else {
 675                 /* Found pac */
 676                 union netr_Validation validation;
 677                 free(principal_string);
 678
 679                 pac = data_blob_talloc(mem_ctx, pac_data.data, pac_data.length);
 680                 if (!pac.data) {
 681                         krb5_free_principal(context, client_principal);
 682                         talloc_free(mem_ctx);
 683                         return NT_STATUS_NO_MEMORY;
 684                 }
 685
 686                 /* decode and verify the pac */
 687                 nt_status = kerberos_pac_logon_info(gensec_krb5_state,
 688                                                     gensec_security->settings->iconv_convenience,
 689                                                     &logon_info, pac,
 690                                                     gensec_krb5_state->smb_krb5_context->krb5_context,
 691                                                     NULL, gensec_krb5_state->keyblock,
 692                                                     client_principal,
 693                                                     gensec_krb5_state->ticket->ticket.authtime, NULL);
 694                 krb5_free_principal(context, client_principal);
 695
 696                 if (!NT_STATUS_IS_OK(nt_status)) {
 697                         talloc_free(mem_ctx);
 698                         return nt_status;
 699                 }
 700
 701                 validation.sam3 = &logon_info->info3;
 702                 nt_status = make_server_info_netlogon_validation(mem_ctx,
 703                                                                  NULL,
 704                                                                  3, &validation,
 705                                                                  &server_info);
 706                 if (!NT_STATUS_IS_OK(nt_status)) {
 707                         talloc_free(mem_ctx);
 708                         return nt_status;
 709                 }
 710         }
 711
 712         /* references the server_info into the session_info */
 713         nt_status = gensec_generate_session_info(mem_ctx, gensec_security, server_info, &session_info);
 714
 715         if (!NT_STATUS_IS_OK(nt_status)) {
 716                 talloc_free(mem_ctx);
 717                 return nt_status;
 718         }
 719
 720         nt_status = gensec_krb5_session_key(gensec_security, &session_info->session_key);
 721
 722         if (!NT_STATUS_IS_OK(nt_status)) {
 723                 talloc_free(mem_ctx);
 724                 return nt_status;
 725         }
 726
 727         *_session_info = session_info;
 728
 729         talloc_steal(gensec_krb5_state, session_info);
 730         talloc_free(mem_ctx);
 731         return NT_STATUS_OK;
 732 }
 733
 734 static NTSTATUS gensec_krb5_wrap(struct gensec_security *gensec_security,
 735                                    TALLOC_CTX *mem_ctx,
 736                                    const DATA_BLOB *in,
 737                                    DATA_BLOB *out)
 738 {
 739         struct gensec_krb5_state *gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
 740         krb5_context context = gensec_krb5_state->smb_krb5_context->krb5_context;
 741         krb5_auth_context auth_context = gensec_krb5_state->auth_context;
 742         krb5_error_code ret;
 743         krb5_data input, output;
 744         input.length = in->length;
 745         input.data = in->data;
 746
 747         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
 748                 ret = krb5_mk_priv(context, auth_context, &input, &output, NULL);
 749                 if (ret) {
 750                         DEBUG(1, ("krb5_mk_priv failed: %s\n",
 751                                   smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context,
 752                                                              ret, mem_ctx)));
 753                         return NT_STATUS_ACCESS_DENIED;
 754                 }
 755                 *out = data_blob_talloc(mem_ctx, output.data, output.length);
 756
 757                 krb5_data_free(&output);
 758         } else {
 759                 return NT_STATUS_ACCESS_DENIED;
 760         }
 761         return NT_STATUS_OK;
 762 }
 763
 764 static NTSTATUS gensec_krb5_unwrap(struct gensec_security *gensec_security,
 765                                      TALLOC_CTX *mem_ctx,
 766                                      const DATA_BLOB *in,
 767                                      DATA_BLOB *out)
 768 {
 769         struct gensec_krb5_state *gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
 770         krb5_context context = gensec_krb5_state->smb_krb5_context->krb5_context;
 771         krb5_auth_context auth_context = gensec_krb5_state->auth_context;
 772         krb5_error_code ret;
 773         krb5_data input, output;
 774         krb5_replay_data replay;
 775         input.length = in->length;
 776         input.data = in->data;
 777
 778         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
 779                 ret = krb5_rd_priv(context, auth_context, &input, &output, &replay);
 780                 if (ret) {
 781                         DEBUG(1, ("krb5_rd_priv failed: %s\n",
 782                                   smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context,
 783                                                              ret, mem_ctx)));
 784                         return NT_STATUS_ACCESS_DENIED;
 785                 }
 786                 *out = data_blob_talloc(mem_ctx, output.data, output.length);
 787
 788                 krb5_data_free(&output);
 789         } else {
 790                 return NT_STATUS_ACCESS_DENIED;
 791         }
 792         return NT_STATUS_OK;
 793 }
 794
 795 static bool gensec_krb5_have_feature(struct gensec_security *gensec_security,
 796                                      uint32_t feature)
 797 {
 798         struct gensec_krb5_state *gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
 799         if (feature & GENSEC_FEATURE_SESSION_KEY) {
 800                 return true;
 801         }
 802         if (!gensec_krb5_state->gssapi &&
 803             (feature & GENSEC_FEATURE_SEAL)) {
 804                 return true;
 805         }
 806
 807         return false;
 808 }
 809
 810 static const char *gensec_krb5_oids[] = {
 811         GENSEC_OID_KERBEROS5,
 812         GENSEC_OID_KERBEROS5_OLD,
 813         NULL
 814 };
 815
 816 static const struct gensec_security_ops gensec_fake_gssapi_krb5_security_ops = {
 817         .name           = "fake_gssapi_krb5",
 818         .auth_type      = DCERPC_AUTH_TYPE_KRB5,
 819         .oid            = gensec_krb5_oids,
 820         .client_start   = gensec_fake_gssapi_krb5_client_start,
 821         .server_start   = gensec_fake_gssapi_krb5_server_start,
 822         .update         = gensec_krb5_update,
 823         .magic          = gensec_fake_gssapi_krb5_magic,
 824         .session_key    = gensec_krb5_session_key,
 825         .session_info   = gensec_krb5_session_info,
 826         .have_feature   = gensec_krb5_have_feature,
 827         .enabled        = false,
 828         .kerberos       = true,
 829         .priority       = GENSEC_KRB5
 830 };
 831
 832 static const struct gensec_security_ops gensec_krb5_security_ops = {
 833         .name           = "krb5",
 834         .client_start   = gensec_krb5_client_start,
 835         .server_start   = gensec_krb5_server_start,
 836         .update         = gensec_krb5_update,
 837         .session_key    = gensec_krb5_session_key,
 838         .session_info   = gensec_krb5_session_info,
 839         .have_feature   = gensec_krb5_have_feature,
 840         .wrap           = gensec_krb5_wrap,
 841         .unwrap         = gensec_krb5_unwrap,
 842         .enabled        = true,
 843         .kerberos       = true,
 844         .priority       = GENSEC_KRB5
 845 };
 846
 847 _PUBLIC_ NTSTATUS gensec_krb5_init(void)
 848 {
 849         NTSTATUS ret;
 850
 851         ret = gensec_register(&gensec_krb5_security_ops);
 852         if (!NT_STATUS_IS_OK(ret)) {
 853                 DEBUG(0,("Failed to register '%s' gensec backend!\n",
 854                         gensec_krb5_security_ops.name));
 855                 return ret;
 856         }
 857
 858         ret = gensec_register(&gensec_fake_gssapi_krb5_security_ops);
 859         if (!NT_STATUS_IS_OK(ret)) {
 860                 DEBUG(0,("Failed to register '%s' gensec backend!\n",
 861                         gensec_krb5_security_ops.name));
 862                 return ret;
 863         }
 864
 865         return ret;
 866 }