lib/gssapi/krb5/init_sec_context.c

   1 /*
   2  * Copyright (c) 1997 - 2002 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     krb5_data_zero(&outbuf);
 211     krb5_data_zero(&fwd_data);
 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         gssapi_krb5_set_error_string ();
 232         *minor_status = kret;
 233         ret = GSS_S_FAILURE;
 234         goto failure;
 235     }
 236
 237     kret = set_addresses ((*context_handle)->auth_context,
 238                           input_chan_bindings);
 239     if (kret) {
 240         *minor_status = kret;
 241         ret = GSS_S_BAD_BINDINGS;
 242         goto failure;
 243     }
 244
 245     {
 246         int32_t tmp;
 247
 248         krb5_auth_con_getflags(gssapi_krb5_context,
 249                                (*context_handle)->auth_context,
 250                                &tmp);
 251         tmp |= KRB5_AUTH_CONTEXT_DO_SEQUENCE;
 252         krb5_auth_con_setflags(gssapi_krb5_context,
 253                                (*context_handle)->auth_context,
 254                                tmp);
 255     }
 256
 257     if (actual_mech_type)
 258         *actual_mech_type = GSS_KRB5_MECHANISM;
 259
 260     if (initiator_cred_handle == GSS_C_NO_CREDENTIAL) {
 261         kret = krb5_cc_default (gssapi_krb5_context, &ccache);
 262         if (kret) {
 263             gssapi_krb5_set_error_string ();
 264             *minor_status = kret;
 265             ret = GSS_S_FAILURE;
 266             goto failure;
 267         }
 268     } else
 269         ccache = initiator_cred_handle->ccache;
 270
 271     kret = krb5_cc_get_principal (gssapi_krb5_context,
 272                                   ccache,
 273                                   &(*context_handle)->source);
 274     if (kret) {
 275         gssapi_krb5_set_error_string ();
 276         *minor_status = kret;
 277         ret = GSS_S_FAILURE;
 278         goto failure;
 279     }
 280
 281     kret = krb5_copy_principal (gssapi_krb5_context,
 282                                 target_name,
 283                                 &(*context_handle)->target);
 284     if (kret) {
 285         gssapi_krb5_set_error_string ();
 286         *minor_status = kret;
 287         ret = GSS_S_FAILURE;
 288         goto failure;
 289     }
 290
 291     memset(&this_cred, 0, sizeof(this_cred));
 292     this_cred.client          = (*context_handle)->source;
 293     this_cred.server          = (*context_handle)->target;
 294     if (time_req) {
 295         krb5_timestamp ts;
 296
 297         krb5_timeofday (gssapi_krb5_context, &ts);
 298         this_cred.times.endtime = ts + time_req;
 299     } else
 300         this_cred.times.endtime   = 0;
 301     this_cred.session.keytype = 0;
 302
 303     kret = krb5_get_credentials (gssapi_krb5_context,
 304                                  KRB5_TC_MATCH_KEYTYPE,
 305                                  ccache,
 306                                  &this_cred,
 307                                  &cred);
 308
 309     if (kret) {
 310         gssapi_krb5_set_error_string ();
 311         *minor_status = kret;
 312         ret = GSS_S_FAILURE;
 313         goto failure;
 314     }
 315
 316     krb5_auth_con_setkey(gssapi_krb5_context,
 317                          (*context_handle)->auth_context,
 318                          &cred->session);
 319
 320     flags = 0;
 321     ap_options = 0;
 322     if (req_flags & GSS_C_DELEG_FLAG)
 323         do_delegation ((*context_handle)->auth_context,
 324                        ccache, cred, target_name, &fwd_data, &flags);
 325
 326     if (req_flags & GSS_C_MUTUAL_FLAG) {
 327         flags |= GSS_C_MUTUAL_FLAG;
 328         ap_options |= AP_OPTS_MUTUAL_REQUIRED;
 329     }
 330
 331     if (req_flags & GSS_C_REPLAY_FLAG)
 332         ;                               /* XXX */
 333     if (req_flags & GSS_C_SEQUENCE_FLAG)
 334         ;                               /* XXX */
 335     if (req_flags & GSS_C_ANON_FLAG)
 336         ;                               /* XXX */
 337     flags |= GSS_C_CONF_FLAG;
 338     flags |= GSS_C_INTEG_FLAG;
 339     flags |= GSS_C_SEQUENCE_FLAG;
 340     flags |= GSS_C_TRANS_FLAG;
 341
 342     if (ret_flags)
 343         *ret_flags = flags;
 344     (*context_handle)->flags = flags;
 345     (*context_handle)->more_flags = LOCAL;
 346
 347     ret = gssapi_krb5_create_8003_checksum (minor_status,
 348                                             input_chan_bindings,
 349                                             flags,
 350                                             &fwd_data,
 351                                             &cksum);
 352     krb5_data_free (&fwd_data);
 353     if (ret)
 354         goto failure;
 355
 356 #if 1
 357     enctype = (*context_handle)->auth_context->keyblock->keytype;
 358 #else
 359     if ((*context_handle)->auth_context->enctype)
 360         enctype = (*context_handle)->auth_context->enctype;
 361     else {
 362         kret = krb5_keytype_to_enctype(gssapi_krb5_context,
 363                                        (*context_handle)->auth_context->keyblock->keytype,
 364                                        &enctype);
 365         if (kret)
 366             return kret;
 367     }
 368 #endif
 369
 370     kret = krb5_auth_con_generatelocalsubkey(gssapi_krb5_context,
 371                                              (*context_handle)->auth_context,
 372                                              &cred->session);
 373     if(kret) {
 374         gssapi_krb5_set_error_string ();
 375         *minor_status = kret;
 376         ret = GSS_S_FAILURE;
 377         goto failure;
 378     }
 379
 380     kret = krb5_build_authenticator (gssapi_krb5_context,
 381                                      (*context_handle)->auth_context,
 382                                      enctype,
 383                                      cred,
 384                                      &cksum,
 385                                      &auth,
 386                                      &authenticator,
 387                                      KRB5_KU_AP_REQ_AUTH);
 388
 389     if (kret) {
 390         gssapi_krb5_set_error_string ();
 391         *minor_status = kret;
 392         ret = GSS_S_FAILURE;
 393         goto failure;
 394     }
 395
 396     kret = krb5_build_ap_req (gssapi_krb5_context,
 397                               enctype,
 398                               cred,
 399                               ap_options,
 400                               authenticator,
 401                               &outbuf);
 402
 403     if (kret) {
 404         gssapi_krb5_set_error_string ();
 405         *minor_status = kret;
 406         ret = GSS_S_FAILURE;
 407         goto failure;
 408     }
 409
 410     ret = gssapi_krb5_encapsulate (minor_status, &outbuf, output_token,
 411                                    "\x01\x00");
 412     if (ret)
 413         goto failure;
 414
 415     krb5_data_free (&outbuf);
 416
 417     if (flags & GSS_C_MUTUAL_FLAG) {
 418         return GSS_S_CONTINUE_NEEDED;
 419     } else {
 420         (*context_handle)->more_flags |= OPEN;
 421         return GSS_S_COMPLETE;
 422     }
 423
 424  failure:
 425     krb5_auth_con_free (gssapi_krb5_context,
 426                         (*context_handle)->auth_context);
 427     if((*context_handle)->source)
 428         krb5_free_principal (gssapi_krb5_context,
 429                              (*context_handle)->source);
 430     if((*context_handle)->target)
 431         krb5_free_principal (gssapi_krb5_context,
 432                              (*context_handle)->target);
 433     free (*context_handle);
 434     krb5_data_free (&outbuf);
 435     *context_handle = GSS_C_NO_CONTEXT;
 436     return ret;
 437 }
 438
 439 static OM_uint32
 440 repl_mutual
 441            (OM_uint32 * minor_status,
 442             const gss_cred_id_t initiator_cred_handle,
 443             gss_ctx_id_t * context_handle,
 444             const gss_name_t target_name,
 445             const gss_OID mech_type,
 446             OM_uint32 req_flags,
 447             OM_uint32 time_req,
 448             const gss_channel_bindings_t input_chan_bindings,
 449             const gss_buffer_t input_token,
 450             gss_OID * actual_mech_type,
 451             gss_buffer_t output_token,
 452             OM_uint32 * ret_flags,
 453             OM_uint32 * time_rec
 454            )
 455 {
 456     OM_uint32 ret;
 457     krb5_error_code kret;
 458     krb5_data indata;
 459     krb5_ap_rep_enc_part *repl;
 460
 461     ret = gssapi_krb5_decapsulate (minor_status, input_token, &indata,
 462                                    "\x02\x00");
 463     if (ret)
 464                                 /* XXX - Handle AP_ERROR */
 465         return ret;
 466
 467     kret = krb5_rd_rep (gssapi_krb5_context,
 468                         (*context_handle)->auth_context,
 469                         &indata,
 470                         &repl);
 471     if (kret) {
 472         gssapi_krb5_set_error_string ();
 473         *minor_status = kret;
 474         return GSS_S_FAILURE;
 475     }
 476     krb5_free_ap_rep_enc_part (gssapi_krb5_context,
 477                                repl);
 478
 479     output_token->length = 0;
 480
 481     (*context_handle)->more_flags |= OPEN;
 482
 483     return GSS_S_COMPLETE;
 484 }
 485
 486 /*
 487  * gss_init_sec_context
 488  */
 489
 490 OM_uint32 gss_init_sec_context
 491            (OM_uint32 * minor_status,
 492             const gss_cred_id_t initiator_cred_handle,
 493             gss_ctx_id_t * context_handle,
 494             const gss_name_t target_name,
 495             const gss_OID mech_type,
 496             OM_uint32 req_flags,
 497             OM_uint32 time_req,
 498             const gss_channel_bindings_t input_chan_bindings,
 499             const gss_buffer_t input_token,
 500             gss_OID * actual_mech_type,
 501             gss_buffer_t output_token,
 502             OM_uint32 * ret_flags,
 503             OM_uint32 * time_rec
 504            )
 505 {
 506     gssapi_krb5_init ();
 507
 508     if (input_token == GSS_C_NO_BUFFER || input_token->length == 0)
 509         return init_auth (minor_status,
 510                           initiator_cred_handle,
 511                           context_handle,
 512                           target_name,
 513                           mech_type,
 514                           req_flags,
 515                           time_req,
 516                           input_chan_bindings,
 517                           input_token,
 518                           actual_mech_type,
 519                           output_token,
 520                           ret_flags,
 521                           time_rec);
 522     else
 523         return repl_mutual(minor_status,
 524                            initiator_cred_handle,
 525                            context_handle,
 526                            target_name,
 527                            mech_type,
 528                            req_flags,
 529                            time_req,
 530                            input_chan_bindings,
 531                            input_token,
 532                            actual_mech_type,
 533                            output_token,
 534                            ret_flags,
 535                            time_rec);
 536 }