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 "gsskrb5_locl.h"
  35
  36 RCSID("$Id$");
  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     /*
 132      * If we have a preferred principal, lets try to find it in all
 133      * caches, otherwise, fall back to default cache, ignore all
 134      * errors while searching.
 135      */
 136
 137     if (handle->principal) {
 138         kret = krb5_cc_cache_match (context,
 139                                     handle->principal,
 140                                     &ccache);
 141         if (kret == 0) {
 142             ret = GSS_S_COMPLETE;
 143             goto found;
 144         }
 145     }
 146
 147     if (ccache == NULL) {
 148         kret = krb5_cc_default(context, &ccache);
 149         if (kret)
 150             goto end;
 151     }
 152     kret = krb5_cc_get_principal(context, ccache, &def_princ);
 153     if (kret != 0) {
 154         /* we'll try to use a keytab below */
 155         krb5_cc_close(context, ccache);
 156         def_princ = NULL;
 157         kret = 0;
 158     } else if (handle->principal == NULL)  {
 159         kret = krb5_copy_principal(context, def_princ, &handle->principal);
 160         if (kret)
 161             goto end;
 162     } else if (handle->principal != NULL &&
 163                krb5_principal_compare(context, handle->principal,
 164                                       def_princ) == FALSE) {
 165         krb5_free_principal(context, def_princ);
 166         def_princ = NULL;
 167         krb5_cc_close(context, ccache);
 168         ccache = NULL;
 169     }
 170     if (def_princ == NULL) {
 171         /* We have no existing credentials cache,
 172          * so attempt to get a TGT using a keytab.
 173          */
 174         if (handle->principal == NULL) {
 175             kret = krb5_get_default_principal(context, &handle->principal);
 176             if (kret)
 177                 goto end;
 178         }
 179         kret = get_keytab(context, &keytab);
 180         if (kret)
 181             goto end;
 182         kret = krb5_get_init_creds_opt_alloc(context, &opt);
 183         if (kret)
 184             goto end;
 185         kret = krb5_get_init_creds_keytab(context, &cred,
 186             handle->principal, keytab, 0, NULL, opt);
 187         krb5_get_init_creds_opt_free(context, opt);
 188         if (kret)
 189             goto end;
 190         kret = krb5_cc_new_unique(context, krb5_cc_type_memory,
 191                                   NULL, &ccache);
 192         if (kret)
 193             goto end;
 194         kret = krb5_cc_initialize(context, ccache, cred.client);
 195         if (kret) {
 196             krb5_cc_destroy(context, ccache);
 197             goto end;
 198         }
 199         kret = krb5_cc_store_cred(context, ccache, &cred);
 200         if (kret) {
 201             krb5_cc_destroy(context, ccache);
 202             goto end;
 203         }
 204         handle->lifetime = cred.times.endtime;
 205         handle->cred_flags |= GSS_CF_DESTROY_CRED_ON_RELEASE;
 206     } else {
 207
 208         ret = __gsskrb5_ccache_lifetime(minor_status,
 209                                         context,
 210                                         ccache,
 211                                         handle->principal,
 212                                         &handle->lifetime);
 213         if (ret != GSS_S_COMPLETE) {
 214             krb5_cc_close(context, ccache);
 215             goto end;
 216         }
 217         kret = 0;
 218     }
 219  found:
 220     handle->ccache = ccache;
 221     ret = GSS_S_COMPLETE;
 222
 223 end:
 224     if (cred.client != NULL)
 225         krb5_free_cred_contents(context, &cred);
 226     if (def_princ != NULL)
 227         krb5_free_principal(context, def_princ);
 228     if (keytab != NULL)
 229         krb5_kt_close(context, keytab);
 230     if (ret != GSS_S_COMPLETE && kret != 0)
 231         *minor_status = kret;
 232     return (ret);
 233 }
 234
 235 static OM_uint32 acquire_acceptor_cred
 236                   (OM_uint32 * minor_status,
 237                    krb5_context context,
 238                    const gss_name_t desired_name,
 239                    OM_uint32 time_req,
 240                    const gss_OID_set desired_mechs,
 241                    gss_cred_usage_t cred_usage,
 242                    gsskrb5_cred handle,
 243                    gss_OID_set * actual_mechs,
 244                    OM_uint32 * time_rec
 245                   )
 246 {
 247     OM_uint32 ret;
 248     krb5_error_code kret;
 249
 250     ret = GSS_S_FAILURE;
 251     kret = get_keytab(context, &handle->keytab);
 252     if (kret)
 253         goto end;
 254
 255     /* check that the requested principal exists in the keytab */
 256     if (handle->principal) {
 257         krb5_keytab_entry entry;
 258
 259         kret = krb5_kt_get_entry(context, handle->keytab,
 260                                  handle->principal, 0, 0, &entry);
 261         if (kret)
 262             goto end;
 263         krb5_kt_free_entry(context, &entry);
 264         ret = GSS_S_COMPLETE;
 265     } else {
 266         /*
 267          * Check if there is at least one entry in the keytab before
 268          * declaring it as an useful keytab.
 269          */
 270         krb5_keytab_entry tmp;
 271         krb5_kt_cursor c;
 272
 273         kret = krb5_kt_start_seq_get (context, handle->keytab, &c);
 274         if (kret)
 275             goto end;
 276         if (krb5_kt_next_entry(context, handle->keytab, &tmp, &c) == 0) {
 277             krb5_kt_free_entry(context, &tmp);
 278             ret = GSS_S_COMPLETE; /* ok found one entry */
 279         }
 280         krb5_kt_end_seq_get (context, handle->keytab, &c);
 281     }
 282 end:
 283     if (ret != GSS_S_COMPLETE) {
 284         if (handle->keytab != NULL)
 285             krb5_kt_close(context, handle->keytab);
 286         if (kret != 0) {
 287             *minor_status = kret;
 288         }
 289     }
 290     return (ret);
 291 }
 292
 293 OM_uint32 _gsskrb5_acquire_cred
 294 (OM_uint32 * minor_status,
 295  const gss_name_t desired_name,
 296  OM_uint32 time_req,
 297  const gss_OID_set desired_mechs,
 298  gss_cred_usage_t cred_usage,
 299  gss_cred_id_t * output_cred_handle,
 300  gss_OID_set * actual_mechs,
 301  OM_uint32 * time_rec
 302     )
 303 {
 304     krb5_context context;
 305     gsskrb5_cred handle;
 306     OM_uint32 ret;
 307
 308     if (cred_usage != GSS_C_ACCEPT && cred_usage != GSS_C_INITIATE && cred_usage != GSS_C_BOTH) {
 309         *minor_status = GSS_KRB5_S_G_BAD_USAGE;
 310         return GSS_S_FAILURE;
 311     }
 312
 313     GSSAPI_KRB5_INIT(&context);
 314
 315     *output_cred_handle = NULL;
 316     if (time_rec)
 317         *time_rec = 0;
 318     if (actual_mechs)
 319         *actual_mechs = GSS_C_NO_OID_SET;
 320
 321     if (desired_mechs) {
 322         int present = 0;
 323
 324         ret = gss_test_oid_set_member(minor_status, GSS_KRB5_MECHANISM,
 325                                       desired_mechs, &present);
 326         if (ret)
 327             return ret;
 328         if (!present) {
 329             *minor_status = 0;
 330             return GSS_S_BAD_MECH;
 331         }
 332     }
 333
 334     handle = calloc(1, sizeof(*handle));
 335     if (handle == NULL) {
 336         *minor_status = ENOMEM;
 337         return (GSS_S_FAILURE);
 338     }
 339
 340     HEIMDAL_MUTEX_init(&handle->cred_id_mutex);
 341
 342     if (desired_name != GSS_C_NO_NAME) {
 343
 344         ret = _gsskrb5_canon_name(minor_status, context, 0, desired_name,
 345                                   &handle->principal);
 346         if (ret) {
 347             HEIMDAL_MUTEX_destroy(&handle->cred_id_mutex);
 348             free(handle);
 349             return ret;
 350         }
 351     }
 352     if (cred_usage == GSS_C_INITIATE || cred_usage == GSS_C_BOTH) {
 353         ret = acquire_initiator_cred(minor_status, context,
 354                                      desired_name, time_req,
 355                                      desired_mechs, cred_usage, handle,
 356                                      actual_mechs, time_rec);
 357         if (ret != GSS_S_COMPLETE) {
 358             HEIMDAL_MUTEX_destroy(&handle->cred_id_mutex);
 359             krb5_free_principal(context, handle->principal);
 360             free(handle);
 361             return (ret);
 362         }
 363     }
 364     if (cred_usage == GSS_C_ACCEPT || cred_usage == GSS_C_BOTH) {
 365         ret = acquire_acceptor_cred(minor_status, context,
 366                                     desired_name, time_req,
 367                                     desired_mechs, cred_usage, handle, actual_mechs, time_rec);
 368         if (ret != GSS_S_COMPLETE) {
 369             HEIMDAL_MUTEX_destroy(&handle->cred_id_mutex);
 370             krb5_free_principal(context, handle->principal);
 371             free(handle);
 372             return (ret);
 373         }
 374     }
 375     ret = gss_create_empty_oid_set(minor_status, &handle->mechanisms);
 376     if (ret == GSS_S_COMPLETE)
 377         ret = gss_add_oid_set_member(minor_status, GSS_KRB5_MECHANISM,
 378                                      &handle->mechanisms);
 379     if (ret == GSS_S_COMPLETE)
 380         ret = _gsskrb5_inquire_cred(minor_status, (gss_cred_id_t)handle,
 381                                     NULL, time_rec, NULL, actual_mechs);
 382     if (ret != GSS_S_COMPLETE) {
 383         if (handle->mechanisms != NULL)
 384             gss_release_oid_set(NULL, &handle->mechanisms);
 385         HEIMDAL_MUTEX_destroy(&handle->cred_id_mutex);
 386         krb5_free_principal(context, handle->principal);
 387         free(handle);
 388         return (ret);
 389     }
 390     *minor_status = 0;
 391     if (time_rec) {
 392         ret = _gsskrb5_lifetime_left(minor_status,
 393                                      context,
 394                                      handle->lifetime,
 395                                      time_rec);
 396
 397         if (ret)
 398             return ret;
 399     }
 400     handle->usage = cred_usage;
 401     *output_cred_handle = (gss_cred_id_t)handle;
 402     return (GSS_S_COMPLETE);
 403 }