lib/gssapi/init_sec_context.c

   1 /*
   2  * Copyright (c) 1997 - 2000 Kungliga Tekniska Högskolan
   3  * (Royal Institute of Technology, Stockholm, Sweden).
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  *
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  *
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  *
  17  * 3. Neither the name of the Institute nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #include "gssapi_locl.h"
  35
  36 RCSID("$Id$");
  37
  38 /*
  39  * copy the addresses from `input_chan_bindings' (if any) to
  40  * the auth context `ac'
  41  */
  42
  43 static OM_uint32
  44 set_addresses (krb5_auth_context ac,
  45                const gss_channel_bindings_t input_chan_bindings)
  46 {
  47     /* Port numbers are expected to be in application_data.value,
  48      * initator's port first */
  49
  50     krb5_address initiator_addr, acceptor_addr;
  51     krb5_error_code kret;
  52
  53     if (input_chan_bindings == GSS_C_NO_CHANNEL_BINDINGS
  54         || input_chan_bindings->application_data.length !=
  55         2 * sizeof(ac->local_port))
  56         return 0;
  57
  58     memset(&initiator_addr, 0, sizeof(initiator_addr));
  59     memset(&acceptor_addr, 0, sizeof(acceptor_addr));
  60
  61     ac->local_port =
  62         *(int16_t *) input_chan_bindings->application_data.value;
  63
  64     ac->remote_port =
  65         *((int16_t *) input_chan_bindings->application_data.value + 1);
  66
  67     kret = gss_address_to_krb5addr(input_chan_bindings->acceptor_addrtype,
  68                                    &input_chan_bindings->acceptor_address,
  69                                    ac->remote_port,
  70                                    &acceptor_addr);
  71     if (kret)
  72         return kret;
  73
  74     kret = gss_address_to_krb5addr(input_chan_bindings->initiator_addrtype,
  75                                    &input_chan_bindings->initiator_address,
  76                                    ac->local_port,
  77                                    &initiator_addr);
  78     if (kret) {
  79         krb5_free_address (gssapi_krb5_context, &acceptor_addr);
  80         return kret;
  81     }
  82
  83     kret = krb5_auth_con_setaddrs(gssapi_krb5_context,
  84                                   ac,
  85                                   &initiator_addr,  /* local address */
  86                                   &acceptor_addr);  /* remote address */
  87
  88     krb5_free_address (gssapi_krb5_context, &initiator_addr);
  89     krb5_free_address (gssapi_krb5_context, &acceptor_addr);
  90
  91 #if 0
  92     free(input_chan_bindings->application_data.value);
  93     input_chan_bindings->application_data.value = NULL;
  94     input_chan_bindings->application_data.length = 0;
  95 #endif
  96
  97     return kret;
  98 }
  99
 100 /*
 101  * handle delegated creds in init-sec-context
 102  */
 103
 104 static void
 105 do_delegation (krb5_auth_context ac,
 106                krb5_ccache ccache,
 107                krb5_creds *cred,
 108                const gss_name_t target_name,
 109                krb5_data *fwd_data,
 110                int *flags)
 111 {
 112     krb5_creds creds;
 113     krb5_kdc_flags fwd_flags;
 114     krb5_keyblock *subkey;
 115     krb5_error_code kret;
 116
 117     memset (&creds, 0, sizeof(creds));
 118     krb5_data_zero (fwd_data);
 119
 120     kret = krb5_generate_subkey (gssapi_krb5_context, &cred->session, &subkey);
 121     if (kret)
 122         goto out;
 123
 124     kret = krb5_auth_con_setlocalsubkey(gssapi_krb5_context, ac, subkey);
 125     krb5_free_keyblock (gssapi_krb5_context, subkey);
 126     if (kret)
 127         goto out;
 128
 129     kret = krb5_cc_get_principal(gssapi_krb5_context, ccache, &creds.client);
 130     if (kret)
 131         goto out;
 132
 133     kret = krb5_build_principal(gssapi_krb5_context,
 134                                 &creds.server,
 135                                 strlen(creds.client->realm),
 136                                 creds.client->realm,
 137                                 KRB5_TGS_NAME,
 138                                 creds.client->realm,
 139                                 NULL);
 140     if (kret)
 141         goto out;
 142
 143     creds.times.endtime = 0;
 144
 145     fwd_flags.i = 0;
 146     fwd_flags.b.forwarded = 1;
 147     fwd_flags.b.forwardable = 1;
 148
 149     if ( /*target_name->name.name_type != KRB5_NT_SRV_HST ||*/
 150         target_name->name.name_string.len < 2)
 151         goto out;
 152
 153     kret = krb5_get_forwarded_creds(gssapi_krb5_context,
 154                                     ac,
 155                                     ccache,
 156                                     fwd_flags.i,
 157                                     target_name->name.name_string.val[1],
 158                                     &creds,
 159                                     fwd_data);
 160
 161  out:
 162     if (kret)
 163         *flags &= ~GSS_C_DELEG_FLAG;
 164     else
 165         *flags |= GSS_C_DELEG_FLAG;
 166
 167     if (creds.client)
 168         krb5_free_principal(gssapi_krb5_context, creds.client);
 169     if (creds.server)
 170         krb5_free_principal(gssapi_krb5_context, creds.server);
 171 }
 172
 173 /*
 174  * first stage of init-sec-context
 175  */
 176
 177 static OM_uint32
 178 init_auth
 179            (OM_uint32 * minor_status,
 180             const gss_cred_id_t initiator_cred_handle,
 181             gss_ctx_id_t * context_handle,
 182             const gss_name_t target_name,
 183             const gss_OID mech_type,
 184             OM_uint32 req_flags,
 185             OM_uint32 time_req,
 186             const gss_channel_bindings_t input_chan_bindings,
 187             const gss_buffer_t input_token,
 188             gss_OID * actual_mech_type,
 189             gss_buffer_t output_token,
 190             OM_uint32 * ret_flags,
 191             OM_uint32 * time_rec
 192            )
 193 {
 194     OM_uint32 ret = GSS_S_FAILURE;
 195     krb5_error_code kret;
 196     krb5_flags ap_options;
 197     krb5_creds this_cred, *cred;
 198     krb5_data outbuf;
 199     krb5_ccache ccache;
 200     u_int32_t flags;
 201     Authenticator *auth;
 202     krb5_data authenticator;
 203     Checksum cksum;
 204     krb5_enctype enctype;
 205     krb5_data fwd_data;
 206
 207     output_token->length = 0;
 208     output_token->value  = NULL;
 209
 210     outbuf.length = 0;
 211     outbuf.data   = NULL;
 212
 213     *minor_status = 0;
 214
 215     *context_handle = malloc(sizeof(**context_handle));
 216     if (*context_handle == NULL) {
 217         *minor_status = ENOMEM;
 218         return GSS_S_FAILURE;
 219     }
 220
 221     (*context_handle)->auth_context = NULL;
 222     (*context_handle)->source       = NULL;
 223     (*context_handle)->target       = NULL;
 224     (*context_handle)->flags        = 0;
 225     (*context_handle)->more_flags   = 0;
 226     (*context_handle)->ticket       = NULL;
 227
 228     kret = krb5_auth_con_init (gssapi_krb5_context,
 229                                &(*context_handle)->auth_context);
 230     if (kret) {
 231         *minor_status = kret;
 232         ret = GSS_S_FAILURE;
 233         goto failure;
 234     }
 235
 236     kret = set_addresses ((*context_handle)->auth_context,
 237                           input_chan_bindings);
 238     if (kret) {
 239         *minor_status = kret;
 240         ret = GSS_S_BAD_BINDINGS;
 241         goto failure;
 242     }
 243
 244     {
 245         int32_t tmp;
 246
 247         krb5_auth_con_getflags(gssapi_krb5_context,
 248                                (*context_handle)->auth_context,
 249                                &tmp);
 250         tmp |= KRB5_AUTH_CONTEXT_DO_SEQUENCE;
 251         krb5_auth_con_setflags(gssapi_krb5_context,
 252                                (*context_handle)->auth_context,
 253                                tmp);
 254     }
 255
 256     if (actual_mech_type)
 257         *actual_mech_type = GSS_KRB5_MECHANISM;
 258
 259     kret = krb5_cc_default (gssapi_krb5_context, &ccache);
 260     if (kret) {
 261         *minor_status = kret;
 262         ret = GSS_S_FAILURE;
 263         goto failure;
 264     }
 265
 266     kret = krb5_cc_get_principal (gssapi_krb5_context,
 267                                   ccache,
 268                                   &(*context_handle)->source);
 269     if (kret) {
 270         *minor_status = kret;
 271         ret = GSS_S_FAILURE;
 272         goto failure;
 273     }
 274
 275     kret = krb5_copy_principal (gssapi_krb5_context,
 276                                 target_name,
 277                                 &(*context_handle)->target);
 278     if (kret) {
 279         *minor_status = kret;
 280         ret = GSS_S_FAILURE;
 281         goto failure;
 282     }
 283
 284     memset(&this_cred, 0, sizeof(this_cred));
 285     this_cred.client          = (*context_handle)->source;
 286     this_cred.server          = (*context_handle)->target;
 287     if (time_req) {
 288         krb5_timestamp ts;
 289
 290         krb5_timeofday (gssapi_krb5_context, &ts);
 291         this_cred.times.endtime = ts + time_req;
 292     } else
 293         this_cred.times.endtime   = 0;
 294     this_cred.session.keytype = 0;
 295
 296     kret = krb5_get_credentials (gssapi_krb5_context,
 297                                  KRB5_TC_MATCH_KEYTYPE,
 298                                  ccache,
 299                                  &this_cred,
 300                                  &cred);
 301
 302     if (kret) {
 303         *minor_status = kret;
 304         ret = GSS_S_FAILURE;
 305         goto failure;
 306     }
 307
 308     krb5_auth_con_setkey(gssapi_krb5_context,
 309                          (*context_handle)->auth_context,
 310                          &cred->session);
 311
 312     flags = 0;
 313     ap_options = 0;
 314     if (req_flags & GSS_C_DELEG_FLAG)
 315         do_delegation ((*context_handle)->auth_context,
 316                        ccache, cred, target_name, &fwd_data, &flags);
 317
 318     if (req_flags & GSS_C_MUTUAL_FLAG) {
 319        flags |= GSS_C_MUTUAL_FLAG;
 320        ap_options |= AP_OPTS_MUTUAL_REQUIRED;
 321     }
 322
 323     if (req_flags & GSS_C_REPLAY_FLAG)
 324        ;                               /* XXX */
 325     if (req_flags & GSS_C_SEQUENCE_FLAG)
 326        ;                               /* XXX */
 327     if (req_flags & GSS_C_ANON_FLAG)
 328        ;                               /* XXX */
 329     flags |= GSS_C_CONF_FLAG;
 330     flags |= GSS_C_INTEG_FLAG;
 331     flags |= GSS_C_SEQUENCE_FLAG;
 332     flags |= GSS_C_TRANS_FLAG;
 333
 334     if (ret_flags)
 335        *ret_flags = flags;
 336     (*context_handle)->flags = flags;
 337     (*context_handle)->more_flags = LOCAL;
 338
 339     kret = gssapi_krb5_create_8003_checksum (input_chan_bindings,
 340                                              flags,
 341                                              &fwd_data,
 342                                              &cksum);
 343     krb5_data_free (&fwd_data);
 344     if (kret) {
 345         *minor_status = kret;
 346         ret = GSS_S_FAILURE;
 347         goto failure;
 348     }
 349
 350 #if 1
 351     enctype = (*context_handle)->auth_context->keyblock->keytype;
 352 #else
 353     if ((*context_handle)->auth_context->enctype)
 354         enctype = (*context_handle)->auth_context->enctype;
 355     else {
 356         kret = krb5_keytype_to_enctype(gssapi_krb5_context,
 357                                        (*context_handle)->auth_context->keyblock->keytype,
 358                                        &enctype);
 359         if (kret)
 360             return kret;
 361     }
 362 #endif
 363
 364     kret = krb5_build_authenticator (gssapi_krb5_context,
 365                                      (*context_handle)->auth_context,
 366                                      enctype,
 367                                      cred,
 368                                      &cksum,
 369                                      &auth,
 370                                      &authenticator);
 371
 372     if (kret) {
 373         *minor_status = kret;
 374         ret = GSS_S_FAILURE;
 375         goto failure;
 376     }
 377
 378     kret = krb5_build_ap_req (gssapi_krb5_context,
 379                               enctype,
 380                               cred,
 381                               ap_options,
 382                               authenticator,
 383                               &outbuf);
 384
 385     if (kret) {
 386         *minor_status = kret;
 387         ret = GSS_S_FAILURE;
 388         goto failure;
 389     }
 390
 391     ret = gssapi_krb5_encapsulate (&outbuf, output_token, "\x01\x00");
 392     if (ret) {
 393         *minor_status = kret;
 394         goto failure;
 395     }
 396
 397     krb5_data_free (&outbuf);
 398
 399     if (flags & GSS_C_MUTUAL_FLAG) {
 400         return GSS_S_CONTINUE_NEEDED;
 401     } else {
 402         (*context_handle)->more_flags |= OPEN;
 403         return GSS_S_COMPLETE;
 404     }
 405
 406 failure:
 407     krb5_auth_con_free (gssapi_krb5_context,
 408                         (*context_handle)->auth_context);
 409     if((*context_handle)->source)
 410         krb5_free_principal (gssapi_krb5_context,
 411                              (*context_handle)->source);
 412     if((*context_handle)->target)
 413         krb5_free_principal (gssapi_krb5_context,
 414                              (*context_handle)->target);
 415     free (*context_handle);
 416     krb5_data_free (&outbuf);
 417     *context_handle = GSS_C_NO_CONTEXT;
 418     return ret;
 419 }
 420
 421 static OM_uint32
 422 repl_mutual
 423            (OM_uint32 * minor_status,
 424             const gss_cred_id_t initiator_cred_handle,
 425             gss_ctx_id_t * context_handle,
 426             const gss_name_t target_name,
 427             const gss_OID mech_type,
 428             OM_uint32 req_flags,
 429             OM_uint32 time_req,
 430             const gss_channel_bindings_t input_chan_bindings,
 431             const gss_buffer_t input_token,
 432             gss_OID * actual_mech_type,
 433             gss_buffer_t output_token,
 434             OM_uint32 * ret_flags,
 435             OM_uint32 * time_rec
 436            )
 437 {
 438     OM_uint32 ret;
 439     krb5_error_code kret;
 440     krb5_data indata;
 441     krb5_ap_rep_enc_part *repl;
 442
 443     ret = gssapi_krb5_decapsulate (input_token, &indata, "\x02\x00");
 444     if (ret) {
 445                                 /* XXX - Handle AP_ERROR */
 446         return GSS_S_FAILURE;
 447     }
 448
 449     kret = krb5_rd_rep (gssapi_krb5_context,
 450                         (*context_handle)->auth_context,
 451                         &indata,
 452                         &repl);
 453     if (kret)
 454         return GSS_S_FAILURE;
 455     krb5_free_ap_rep_enc_part (gssapi_krb5_context,
 456                                repl);
 457
 458     output_token->length = 0;
 459
 460     (*context_handle)->more_flags |= OPEN;
 461
 462     return GSS_S_COMPLETE;
 463 }
 464
 465 /*
 466  * gss_init_sec_context
 467  */
 468
 469 OM_uint32 gss_init_sec_context
 470            (OM_uint32 * minor_status,
 471             const gss_cred_id_t initiator_cred_handle,
 472             gss_ctx_id_t * context_handle,
 473             const gss_name_t target_name,
 474             const gss_OID mech_type,
 475             OM_uint32 req_flags,
 476             OM_uint32 time_req,
 477             const gss_channel_bindings_t input_chan_bindings,
 478             const gss_buffer_t input_token,
 479             gss_OID * actual_mech_type,
 480             gss_buffer_t output_token,
 481             OM_uint32 * ret_flags,
 482             OM_uint32 * time_rec
 483            )
 484 {
 485     gssapi_krb5_init ();
 486
 487     if (input_token == GSS_C_NO_BUFFER || input_token->length == 0)
 488         return init_auth (minor_status,
 489                           initiator_cred_handle,
 490                           context_handle,
 491                           target_name,
 492                           mech_type,
 493                           req_flags,
 494                           time_req,
 495                           input_chan_bindings,
 496                           input_token,
 497                           actual_mech_type,
 498                           output_token,
 499                           ret_flags,
 500                           time_rec);
 501     else
 502         return repl_mutual(minor_status,
 503                            initiator_cred_handle,
 504                            context_handle,
 505                            target_name,
 506                            mech_type,
 507                            req_flags,
 508                            time_req,
 509                            input_chan_bindings,
 510                            input_token,
 511                            actual_mech_type,
 512                            output_token,
 513                            ret_flags,
 514                            time_rec);
 515 }