crypto/heimdal/lib/gssapi/krb5/acquire_cred.c

   1 /*
   2  * Copyright (c) 1997 - 2005 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 "krb5/gsskrb5_locl.h"
  35
  36 RCSID("$Id: acquire_cred.c 22124 2007-12-04 00:03:52Z lha $");
  37
  38 OM_uint32
  39 __gsskrb5_ccache_lifetime(OM_uint32 *minor_status,
  40                           krb5_context context,
  41                           krb5_ccache id,
  42                           krb5_principal principal,
  43                           OM_uint32 *lifetime)
  44 {
  45     krb5_creds in_cred, *out_cred;
  46     krb5_const_realm realm;
  47     krb5_error_code kret;
  48
  49     memset(&in_cred, 0, sizeof(in_cred));
  50     in_cred.client = principal;
  51
  52     realm = krb5_principal_get_realm(context,  principal);
  53     if (realm == NULL) {
  54         _gsskrb5_clear_status ();
  55         *minor_status = KRB5_PRINC_NOMATCH; /* XXX */
  56         return GSS_S_FAILURE;
  57     }
  58
  59     kret = krb5_make_principal(context, &in_cred.server,
  60                                realm, KRB5_TGS_NAME, realm, NULL);
  61     if (kret) {
  62         *minor_status = kret;
  63         return GSS_S_FAILURE;
  64     }
  65
  66     kret = krb5_get_credentials(context, 0,
  67                                 id, &in_cred, &out_cred);
  68     krb5_free_principal(context, in_cred.server);
  69     if (kret) {
  70         *minor_status = kret;
  71         return GSS_S_FAILURE;
  72     }
  73
  74     *lifetime = out_cred->times.endtime;
  75     krb5_free_creds(context, out_cred);
  76
  77     return GSS_S_COMPLETE;
  78 }
  79
  80
  81
  82
  83 static krb5_error_code
  84 get_keytab(krb5_context context, krb5_keytab *keytab)
  85 {
  86     char kt_name[256];
  87     krb5_error_code kret;
  88
  89     HEIMDAL_MUTEX_lock(&gssapi_keytab_mutex);
  90
  91     if (_gsskrb5_keytab != NULL) {
  92         kret = krb5_kt_get_name(context,
  93                                 _gsskrb5_keytab,
  94                                 kt_name, sizeof(kt_name));
  95         if (kret == 0)
  96             kret = krb5_kt_resolve(context, kt_name, keytab);
  97     } else
  98         kret = krb5_kt_default(context, keytab);
  99
 100     HEIMDAL_MUTEX_unlock(&gssapi_keytab_mutex);
 101
 102     return (kret);
 103 }
 104
 105 static OM_uint32 acquire_initiator_cred
 106                   (OM_uint32 * minor_status,
 107                    krb5_context context,
 108                    const gss_name_t desired_name,
 109                    OM_uint32 time_req,
 110                    const gss_OID_set desired_mechs,
 111                    gss_cred_usage_t cred_usage,
 112                    gsskrb5_cred handle,
 113                    gss_OID_set * actual_mechs,
 114                    OM_uint32 * time_rec
 115                   )
 116 {
 117     OM_uint32 ret;
 118     krb5_creds cred;
 119     krb5_principal def_princ;
 120     krb5_get_init_creds_opt *opt;
 121     krb5_ccache ccache;
 122     krb5_keytab keytab;
 123     krb5_error_code kret;
 124
 125     keytab = NULL;
 126     ccache = NULL;
 127     def_princ = NULL;
 128     ret = GSS_S_FAILURE;
 129     memset(&cred, 0, sizeof(cred));
 130
 131     /* If we have a preferred principal, lets try to find it in all
 132      * caches, otherwise, fall back to default cache.  Ignore
 133      * errors. */
 134     if (handle->principal)
 135         kret = krb5_cc_cache_match (context,
 136                                     handle->principal,
 137                                     NULL,
 138                                     &ccache);
 139
 140     if (ccache == NULL) {
 141         kret = krb5_cc_default(context, &ccache);
 142         if (kret)
 143             goto end;
 144     }
 145     kret = krb5_cc_get_principal(context, ccache,
 146         &def_princ);
 147     if (kret != 0) {
 148         /* we'll try to use a keytab below */
 149         krb5_cc_destroy(context, ccache);
 150         ccache = NULL;
 151         kret = 0;
 152     } else if (handle->principal == NULL)  {
 153         kret = krb5_copy_principal(context, def_princ,
 154             &handle->principal);
 155         if (kret)
 156             goto end;
 157     } else if (handle->principal != NULL &&
 158         krb5_principal_compare(context, handle->principal,
 159         def_princ) == FALSE) {
 160         /* Before failing, lets check the keytab */
 161         krb5_free_principal(context, def_princ);
 162         def_princ = NULL;
 163     }
 164     if (def_princ == NULL) {
 165         /* We have no existing credentials cache,
 166          * so attempt to get a TGT using a keytab.
 167          */
 168         if (handle->principal == NULL) {
 169             kret = krb5_get_default_principal(context,
 170                 &handle->principal);
 171             if (kret)
 172                 goto end;
 173         }
 174         kret = get_keytab(context, &keytab);
 175         if (kret)
 176             goto end;
 177         kret = krb5_get_init_creds_opt_alloc(context, &opt);
 178         if (kret)
 179             goto end;
 180         kret = krb5_get_init_creds_keytab(context, &cred,
 181             handle->principal, keytab, 0, NULL, opt);
 182         krb5_get_init_creds_opt_free(context, opt);
 183         if (kret)
 184             goto end;
 185         kret = krb5_cc_gen_new(context, &krb5_mcc_ops,
 186                 &ccache);
 187         if (kret)
 188             goto end;
 189         kret = krb5_cc_initialize(context, ccache, cred.client);
 190         if (kret)
 191             goto end;
 192         kret = krb5_cc_store_cred(context, ccache, &cred);
 193         if (kret)
 194             goto end;
 195         handle->lifetime = cred.times.endtime;
 196         handle->cred_flags |= GSS_CF_DESTROY_CRED_ON_RELEASE;
 197     } else {
 198
 199         ret = __gsskrb5_ccache_lifetime(minor_status,
 200                                         context,
 201                                         ccache,
 202                                         handle->principal,
 203                                         &handle->lifetime);
 204         if (ret != GSS_S_COMPLETE)
 205             goto end;
 206         kret = 0;
 207     }
 208
 209     handle->ccache = ccache;
 210     ret = GSS_S_COMPLETE;
 211
 212 end:
 213     if (cred.client != NULL)
 214         krb5_free_cred_contents(context, &cred);
 215     if (def_princ != NULL)
 216         krb5_free_principal(context, def_princ);
 217     if (keytab != NULL)
 218         krb5_kt_close(context, keytab);
 219     if (ret != GSS_S_COMPLETE) {
 220         if (ccache != NULL)
 221             krb5_cc_close(context, ccache);
 222         if (kret != 0) {
 223             *minor_status = kret;
 224         }
 225     }
 226     return (ret);
 227 }
 228
 229 static OM_uint32 acquire_acceptor_cred
 230                   (OM_uint32 * minor_status,
 231                    krb5_context context,
 232                    const gss_name_t desired_name,
 233                    OM_uint32 time_req,
 234                    const gss_OID_set desired_mechs,
 235                    gss_cred_usage_t cred_usage,
 236                    gsskrb5_cred handle,
 237                    gss_OID_set * actual_mechs,
 238                    OM_uint32 * time_rec
 239                   )
 240 {
 241     OM_uint32 ret;
 242     krb5_error_code kret;
 243
 244     kret = 0;
 245     ret = GSS_S_FAILURE;
 246     kret = get_keytab(context, &handle->keytab);
 247     if (kret)
 248         goto end;
 249
 250     /* check that the requested principal exists in the keytab */
 251     if (handle->principal) {
 252         krb5_keytab_entry entry;
 253
 254         kret = krb5_kt_get_entry(context, handle->keytab,
 255                                  handle->principal, 0, 0, &entry);
 256         if (kret)
 257             goto end;
 258         krb5_kt_free_entry(context, &entry);
 259         ret = GSS_S_COMPLETE;
 260     } else {
 261         /*
 262          * Check if there is at least one entry in the keytab before
 263          * declaring it as an useful keytab.
 264          */
 265         krb5_keytab_entry tmp;
 266         krb5_kt_cursor c;
 267
 268         kret = krb5_kt_start_seq_get (context, handle->keytab, &c);
 269         if (kret)
 270             goto end;
 271         if (krb5_kt_next_entry(context, handle->keytab, &tmp, &c) == 0) {
 272             krb5_kt_free_entry(context, &tmp);
 273             ret = GSS_S_COMPLETE; /* ok found one entry */
 274         }
 275         krb5_kt_end_seq_get (context, handle->keytab, &c);
 276     }
 277 end:
 278     if (ret != GSS_S_COMPLETE) {
 279         if (handle->keytab != NULL)
 280             krb5_kt_close(context, handle->keytab);
 281         if (kret != 0) {
 282             *minor_status = kret;
 283         }
 284     }
 285     return (ret);
 286 }
 287
 288 OM_uint32 _gsskrb5_acquire_cred
 289 (OM_uint32 * minor_status,
 290  const gss_name_t desired_name,
 291  OM_uint32 time_req,
 292  const gss_OID_set desired_mechs,
 293  gss_cred_usage_t cred_usage,
 294  gss_cred_id_t * output_cred_handle,
 295  gss_OID_set * actual_mechs,
 296  OM_uint32 * time_rec
 297     )
 298 {
 299     krb5_context context;
 300     gsskrb5_cred handle;
 301     OM_uint32 ret;
 302
 303     if (cred_usage != GSS_C_ACCEPT && cred_usage != GSS_C_INITIATE && cred_usage != GSS_C_BOTH) {
 304         *minor_status = GSS_KRB5_S_G_BAD_USAGE;
 305         return GSS_S_FAILURE;
 306     }
 307
 308     GSSAPI_KRB5_INIT(&context);
 309
 310     *output_cred_handle = NULL;
 311     if (time_rec)
 312         *time_rec = 0;
 313     if (actual_mechs)
 314         *actual_mechs = GSS_C_NO_OID_SET;
 315
 316     if (desired_mechs) {
 317         int present = 0;
 318
 319         ret = gss_test_oid_set_member(minor_status, GSS_KRB5_MECHANISM,
 320                                       desired_mechs, &present);
 321         if (ret)
 322             return ret;
 323         if (!present) {
 324             *minor_status = 0;
 325             return GSS_S_BAD_MECH;
 326         }
 327     }
 328
 329     handle = calloc(1, sizeof(*handle));
 330     if (handle == NULL) {
 331         *minor_status = ENOMEM;
 332         return (GSS_S_FAILURE);
 333     }
 334
 335     HEIMDAL_MUTEX_init(&handle->cred_id_mutex);
 336
 337     if (desired_name != GSS_C_NO_NAME) {
 338         krb5_principal name = (krb5_principal)desired_name;
 339         ret = krb5_copy_principal(context, name, &handle->principal);
 340         if (ret) {
 341             HEIMDAL_MUTEX_destroy(&handle->cred_id_mutex);
 342             *minor_status = ret;
 343             free(handle);
 344             return GSS_S_FAILURE;
 345         }
 346     }
 347     if (cred_usage == GSS_C_INITIATE || cred_usage == GSS_C_BOTH) {
 348         ret = acquire_initiator_cred(minor_status, context,
 349                                      desired_name, time_req,
 350                                      desired_mechs, cred_usage, handle,
 351                                      actual_mechs, time_rec);
 352         if (ret != GSS_S_COMPLETE) {
 353             HEIMDAL_MUTEX_destroy(&handle->cred_id_mutex);
 354             krb5_free_principal(context, handle->principal);
 355             free(handle);
 356             return (ret);
 357         }
 358     }
 359     if (cred_usage == GSS_C_ACCEPT || cred_usage == GSS_C_BOTH) {
 360         ret = acquire_acceptor_cred(minor_status, context,
 361                                     desired_name, time_req,
 362                                     desired_mechs, cred_usage, handle, actual_mechs, time_rec);
 363         if (ret != GSS_S_COMPLETE) {
 364             HEIMDAL_MUTEX_destroy(&handle->cred_id_mutex);
 365             krb5_free_principal(context, handle->principal);
 366             free(handle);
 367             return (ret);
 368         }
 369     }
 370     ret = gss_create_empty_oid_set(minor_status, &handle->mechanisms);
 371     if (ret == GSS_S_COMPLETE)
 372         ret = gss_add_oid_set_member(minor_status, GSS_KRB5_MECHANISM,
 373                                      &handle->mechanisms);
 374     if (ret == GSS_S_COMPLETE)
 375         ret = _gsskrb5_inquire_cred(minor_status, (gss_cred_id_t)handle,
 376                                     NULL, time_rec, NULL, actual_mechs);
 377     if (ret != GSS_S_COMPLETE) {
 378         if (handle->mechanisms != NULL)
 379             gss_release_oid_set(NULL, &handle->mechanisms);
 380         HEIMDAL_MUTEX_destroy(&handle->cred_id_mutex);
 381         krb5_free_principal(context, handle->principal);
 382         free(handle);
 383         return (ret);
 384     }
 385     *minor_status = 0;
 386     if (time_rec) {
 387         ret = _gsskrb5_lifetime_left(minor_status,
 388                                      context,
 389                                      handle->lifetime,
 390                                      time_rec);
 391
 392         if (ret)
 393             return ret;
 394     }
 395     handle->usage = cred_usage;
 396     *output_cred_handle = (gss_cred_id_t)handle;
 397     return (GSS_S_COMPLETE);
 398 }