lib/gssapi/krb5/init_sec_context.c

   1 /*
   2  * Copyright (c) 1997 - 2001 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         *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     if (initiator_cred_handle == GSS_C_NO_CREDENTIAL) {
 260         kret = krb5_cc_default (gssapi_krb5_context, &ccache);
 261         if (kret) {
 262             *minor_status = kret;
 263             ret = GSS_S_FAILURE;
 264             goto failure;
 265         }
 266     } else
 267         ccache = initiator_cred_handle->ccache;
 268
 269     kret = krb5_cc_get_principal (gssapi_krb5_context,
 270                                   ccache,
 271                                   &(*context_handle)->source);
 272     if (kret) {
 273         *minor_status = kret;
 274         ret = GSS_S_FAILURE;
 275         goto failure;
 276     }
 277
 278     kret = krb5_copy_principal (gssapi_krb5_context,
 279                                 target_name,
 280                                 &(*context_handle)->target);
 281     if (kret) {
 282         *minor_status = kret;
 283         ret = GSS_S_FAILURE;
 284         goto failure;
 285     }
 286
 287     memset(&this_cred, 0, sizeof(this_cred));
 288     this_cred.client          = (*context_handle)->source;
 289     this_cred.server          = (*context_handle)->target;
 290     if (time_req) {
 291         krb5_timestamp ts;
 292
 293         krb5_timeofday (gssapi_krb5_context, &ts);
 294         this_cred.times.endtime = ts + time_req;
 295     } else
 296         this_cred.times.endtime   = 0;
 297     this_cred.session.keytype = 0;
 298
 299     kret = krb5_get_credentials (gssapi_krb5_context,
 300                                  KRB5_TC_MATCH_KEYTYPE,
 301                                  ccache,
 302                                  &this_cred,
 303                                  &cred);
 304
 305     if (kret) {
 306         *minor_status = kret;
 307         ret = GSS_S_FAILURE;
 308         goto failure;
 309     }
 310
 311     krb5_auth_con_setkey(gssapi_krb5_context,
 312                          (*context_handle)->auth_context,
 313                          &cred->session);
 314
 315     flags = 0;
 316     ap_options = 0;
 317     if (req_flags & GSS_C_DELEG_FLAG)
 318         do_delegation ((*context_handle)->auth_context,
 319                        ccache, cred, target_name, &fwd_data, &flags);
 320
 321     if (req_flags & GSS_C_MUTUAL_FLAG) {
 322         flags |= GSS_C_MUTUAL_FLAG;
 323         ap_options |= AP_OPTS_MUTUAL_REQUIRED;
 324     }
 325
 326     if (req_flags & GSS_C_REPLAY_FLAG)
 327         ;                               /* XXX */
 328     if (req_flags & GSS_C_SEQUENCE_FLAG)
 329         ;                               /* XXX */
 330     if (req_flags & GSS_C_ANON_FLAG)
 331         ;                               /* XXX */
 332     flags |= GSS_C_CONF_FLAG;
 333     flags |= GSS_C_INTEG_FLAG;
 334     flags |= GSS_C_SEQUENCE_FLAG;
 335     flags |= GSS_C_TRANS_FLAG;
 336
 337     if (ret_flags)
 338         *ret_flags = flags;
 339     (*context_handle)->flags = flags;
 340     (*context_handle)->more_flags = LOCAL;
 341
 342     kret = gssapi_krb5_create_8003_checksum (input_chan_bindings,
 343                                              flags,
 344                                              &fwd_data,
 345                                              &cksum);
 346     krb5_data_free (&fwd_data);
 347     if (kret) {
 348         *minor_status = kret;
 349         ret = GSS_S_FAILURE;
 350         goto failure;
 351     }
 352
 353 #if 1
 354     enctype = (*context_handle)->auth_context->keyblock->keytype;
 355 #else
 356     if ((*context_handle)->auth_context->enctype)
 357         enctype = (*context_handle)->auth_context->enctype;
 358     else {
 359         kret = krb5_keytype_to_enctype(gssapi_krb5_context,
 360                                        (*context_handle)->auth_context->keyblock->keytype,
 361                                        &enctype);
 362         if (kret)
 363             return kret;
 364     }
 365 #endif
 366
 367     kret = krb5_build_authenticator (gssapi_krb5_context,
 368                                      (*context_handle)->auth_context,
 369                                      enctype,
 370                                      cred,
 371                                      &cksum,
 372                                      &auth,
 373                                      &authenticator,
 374                                      KRB5_KU_AP_REQ_AUTH);
 375
 376     if (kret) {
 377         *minor_status = kret;
 378         ret = GSS_S_FAILURE;
 379         goto failure;
 380     }
 381
 382     kret = krb5_build_ap_req (gssapi_krb5_context,
 383                               enctype,
 384                               cred,
 385                               ap_options,
 386                               authenticator,
 387                               &outbuf);
 388
 389     if (kret) {
 390         *minor_status = kret;
 391         ret = GSS_S_FAILURE;
 392         goto failure;
 393     }
 394
 395     ret = gssapi_krb5_encapsulate (&outbuf, output_token, "\x01\x00");
 396     if (ret) {
 397         *minor_status = kret;
 398         goto failure;
 399     }
 400
 401     krb5_data_free (&outbuf);
 402
 403     if (flags & GSS_C_MUTUAL_FLAG) {
 404         return GSS_S_CONTINUE_NEEDED;
 405     } else {
 406         (*context_handle)->more_flags |= OPEN;
 407         return GSS_S_COMPLETE;
 408     }
 409
 410  failure:
 411     krb5_auth_con_free (gssapi_krb5_context,
 412                         (*context_handle)->auth_context);
 413     if((*context_handle)->source)
 414         krb5_free_principal (gssapi_krb5_context,
 415                              (*context_handle)->source);
 416     if((*context_handle)->target)
 417         krb5_free_principal (gssapi_krb5_context,
 418                              (*context_handle)->target);
 419     free (*context_handle);
 420     krb5_data_free (&outbuf);
 421     *context_handle = GSS_C_NO_CONTEXT;
 422     return ret;
 423 }
 424
 425 static OM_uint32
 426 repl_mutual
 427            (OM_uint32 * minor_status,
 428             const gss_cred_id_t initiator_cred_handle,
 429             gss_ctx_id_t * context_handle,
 430             const gss_name_t target_name,
 431             const gss_OID mech_type,
 432             OM_uint32 req_flags,
 433             OM_uint32 time_req,
 434             const gss_channel_bindings_t input_chan_bindings,
 435             const gss_buffer_t input_token,
 436             gss_OID * actual_mech_type,
 437             gss_buffer_t output_token,
 438             OM_uint32 * ret_flags,
 439             OM_uint32 * time_rec
 440            )
 441 {
 442     OM_uint32 ret;
 443     krb5_error_code kret;
 444     krb5_data indata;
 445     krb5_ap_rep_enc_part *repl;
 446
 447     ret = gssapi_krb5_decapsulate (input_token, &indata, "\x02\x00");
 448     if (ret) {
 449                                 /* XXX - Handle AP_ERROR */
 450         return GSS_S_FAILURE;
 451     }
 452
 453     kret = krb5_rd_rep (gssapi_krb5_context,
 454                         (*context_handle)->auth_context,
 455                         &indata,
 456                         &repl);
 457     if (kret)
 458         return GSS_S_FAILURE;
 459     krb5_free_ap_rep_enc_part (gssapi_krb5_context,
 460                                repl);
 461
 462     output_token->length = 0;
 463
 464     (*context_handle)->more_flags |= OPEN;
 465
 466     return GSS_S_COMPLETE;
 467 }
 468
 469 /*
 470  * gss_init_sec_context
 471  */
 472
 473 OM_uint32 gss_init_sec_context
 474            (OM_uint32 * minor_status,
 475             const gss_cred_id_t initiator_cred_handle,
 476             gss_ctx_id_t * context_handle,
 477             const gss_name_t target_name,
 478             const gss_OID mech_type,
 479             OM_uint32 req_flags,
 480             OM_uint32 time_req,
 481             const gss_channel_bindings_t input_chan_bindings,
 482             const gss_buffer_t input_token,
 483             gss_OID * actual_mech_type,
 484             gss_buffer_t output_token,
 485             OM_uint32 * ret_flags,
 486             OM_uint32 * time_rec
 487            )
 488 {
 489     gssapi_krb5_init ();
 490
 491     if (input_token == GSS_C_NO_BUFFER || input_token->length == 0)
 492         return init_auth (minor_status,
 493                           initiator_cred_handle,
 494                           context_handle,
 495                           target_name,
 496                           mech_type,
 497                           req_flags,
 498                           time_req,
 499                           input_chan_bindings,
 500                           input_token,
 501                           actual_mech_type,
 502                           output_token,
 503                           ret_flags,
 504                           time_rec);
 505     else
 506         return repl_mutual(minor_status,
 507                            initiator_cred_handle,
 508                            context_handle,
 509                            target_name,
 510                            mech_type,
 511                            req_flags,
 512                            time_req,
 513                            input_chan_bindings,
 514                            input_token,
 515                            actual_mech_type,
 516                            output_token,
 517                            ret_flags,
 518                            time_rec);
 519 }