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("$Id$");
  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                                     NULL,
 141                                     &ccache);
 142
 143     if (ccache == NULL) {
 144         kret = krb5_cc_default(context, &ccache);
 145         if (kret)
 146             goto end;
 147     }
 148     kret = krb5_cc_get_principal(context, ccache, &def_princ);
 149     if (kret != 0) {
 150         /* we'll try to use a keytab below */
 151         krb5_cc_close(context, ccache);
 152         def_princ = NULL;
 153         kret = 0;
 154     } else if (handle->principal == NULL)  {
 155         kret = krb5_copy_principal(context, def_princ, &handle->principal);
 156         if (kret)
 157             goto end;
 158     } else if (handle->principal != NULL &&
 159                krb5_principal_compare(context, handle->principal,
 160                                       def_princ) == FALSE) {
 161         krb5_free_principal(context, def_princ);
 162         def_princ = NULL;
 163         krb5_cc_close(context, ccache);
 164         ccache = NULL;
 165     }
 166     if (def_princ == NULL) {
 167         /* We have no existing credentials cache,
 168          * so attempt to get a TGT using a keytab.
 169          */
 170         if (handle->principal == NULL) {
 171             kret = krb5_get_default_principal(context, &handle->principal);
 172             if (kret)
 173                 goto end;
 174         }
 175         kret = get_keytab(context, &keytab);
 176         if (kret)
 177             goto end;
 178         kret = krb5_get_init_creds_opt_alloc(context, &opt);
 179         if (kret)
 180             goto end;
 181         kret = krb5_get_init_creds_keytab(context, &cred,
 182             handle->principal, keytab, 0, NULL, opt);
 183         krb5_get_init_creds_opt_free(context, opt);
 184         if (kret)
 185             goto end;
 186         kret = krb5_cc_gen_new(context, &krb5_mcc_ops, &ccache);
 187         if (kret)
 188             goto end;
 189         kret = krb5_cc_initialize(context, ccache, cred.client);
 190         if (kret) {
 191             krb5_cc_destroy(context, ccache);
 192             goto end;
 193         }
 194         kret = krb5_cc_store_cred(context, ccache, &cred);
 195         if (kret) {
 196             krb5_cc_destroy(context, ccache);
 197             goto end;
 198         }
 199         handle->lifetime = cred.times.endtime;
 200         handle->cred_flags |= GSS_CF_DESTROY_CRED_ON_RELEASE;
 201     } else {
 202
 203         ret = __gsskrb5_ccache_lifetime(minor_status,
 204                                         context,
 205                                         ccache,
 206                                         handle->principal,
 207                                         &handle->lifetime);
 208         if (ret != GSS_S_COMPLETE) {
 209             krb5_cc_close(context, ccache);
 210             goto end;
 211         }
 212         kret = 0;
 213     }
 214
 215     handle->ccache = ccache;
 216     ret = GSS_S_COMPLETE;
 217
 218 end:
 219     if (cred.client != NULL)
 220         krb5_free_cred_contents(context, &cred);
 221     if (def_princ != NULL)
 222         krb5_free_principal(context, def_princ);
 223     if (keytab != NULL)
 224         krb5_kt_close(context, keytab);
 225     if (ret != GSS_S_COMPLETE && kret != 0)
 226         *minor_status = kret;
 227     return (ret);
 228 }
 229
 230 static OM_uint32 acquire_acceptor_cred
 231                   (OM_uint32 * minor_status,
 232                    krb5_context context,
 233                    const gss_name_t desired_name,
 234                    OM_uint32 time_req,
 235                    const gss_OID_set desired_mechs,
 236                    gss_cred_usage_t cred_usage,
 237                    gsskrb5_cred handle,
 238                    gss_OID_set * actual_mechs,
 239                    OM_uint32 * time_rec
 240                   )
 241 {
 242     OM_uint32 ret;
 243     krb5_error_code kret;
 244
 245     kret = 0;
 246     ret = GSS_S_FAILURE;
 247     kret = get_keytab(context, &handle->keytab);
 248     if (kret)
 249         goto end;
 250
 251     /* check that the requested principal exists in the keytab */
 252     if (handle->principal) {
 253         krb5_keytab_entry entry;
 254
 255         kret = krb5_kt_get_entry(context, handle->keytab,
 256                                  handle->principal, 0, 0, &entry);
 257         if (kret)
 258             goto end;
 259         krb5_kt_free_entry(context, &entry);
 260         ret = GSS_S_COMPLETE;
 261     } else {
 262         /*
 263          * Check if there is at least one entry in the keytab before
 264          * declaring it as an useful keytab.
 265          */
 266         krb5_keytab_entry tmp;
 267         krb5_kt_cursor c;
 268
 269         kret = krb5_kt_start_seq_get (context, handle->keytab, &c);
 270         if (kret)
 271             goto end;
 272         if (krb5_kt_next_entry(context, handle->keytab, &tmp, &c) == 0) {
 273             krb5_kt_free_entry(context, &tmp);
 274             ret = GSS_S_COMPLETE; /* ok found one entry */
 275         }
 276         krb5_kt_end_seq_get (context, handle->keytab, &c);
 277     }
 278 end:
 279     if (ret != GSS_S_COMPLETE) {
 280         if (handle->keytab != NULL)
 281             krb5_kt_close(context, handle->keytab);
 282         if (kret != 0) {
 283             *minor_status = kret;
 284         }
 285     }
 286     return (ret);
 287 }
 288
 289 OM_uint32 _gsskrb5_acquire_cred
 290 (OM_uint32 * minor_status,
 291  const gss_name_t desired_name,
 292  OM_uint32 time_req,
 293  const gss_OID_set desired_mechs,
 294  gss_cred_usage_t cred_usage,
 295  gss_cred_id_t * output_cred_handle,
 296  gss_OID_set * actual_mechs,
 297  OM_uint32 * time_rec
 298     )
 299 {
 300     krb5_context context;
 301     gsskrb5_cred handle;
 302     OM_uint32 ret;
 303
 304     if (cred_usage != GSS_C_ACCEPT && cred_usage != GSS_C_INITIATE && cred_usage != GSS_C_BOTH) {
 305         *minor_status = GSS_KRB5_S_G_BAD_USAGE;
 306         return GSS_S_FAILURE;
 307     }
 308
 309     GSSAPI_KRB5_INIT(&context);
 310
 311     *output_cred_handle = NULL;
 312     if (time_rec)
 313         *time_rec = 0;
 314     if (actual_mechs)
 315         *actual_mechs = GSS_C_NO_OID_SET;
 316
 317     if (desired_mechs) {
 318         int present = 0;
 319
 320         ret = gss_test_oid_set_member(minor_status, GSS_KRB5_MECHANISM,
 321                                       desired_mechs, &present);
 322         if (ret)
 323             return ret;
 324         if (!present) {
 325             *minor_status = 0;
 326             return GSS_S_BAD_MECH;
 327         }
 328     }
 329
 330     handle = calloc(1, sizeof(*handle));
 331     if (handle == NULL) {
 332         *minor_status = ENOMEM;
 333         return (GSS_S_FAILURE);
 334     }
 335
 336     HEIMDAL_MUTEX_init(&handle->cred_id_mutex);
 337
 338     if (desired_name != GSS_C_NO_NAME) {
 339         krb5_principal name = (krb5_principal)desired_name;
 340         ret = krb5_copy_principal(context, name, &handle->principal);
 341         if (ret) {
 342             HEIMDAL_MUTEX_destroy(&handle->cred_id_mutex);
 343             *minor_status = ret;
 344             free(handle);
 345             return GSS_S_FAILURE;
 346         }
 347     }
 348     if (cred_usage == GSS_C_INITIATE || cred_usage == GSS_C_BOTH) {
 349         ret = acquire_initiator_cred(minor_status, context,
 350                                      desired_name, time_req,
 351                                      desired_mechs, cred_usage, handle,
 352                                      actual_mechs, time_rec);
 353         if (ret != GSS_S_COMPLETE) {
 354             HEIMDAL_MUTEX_destroy(&handle->cred_id_mutex);
 355             krb5_free_principal(context, handle->principal);
 356             free(handle);
 357             return (ret);
 358         }
 359     }
 360     if (cred_usage == GSS_C_ACCEPT || cred_usage == GSS_C_BOTH) {
 361         ret = acquire_acceptor_cred(minor_status, context,
 362                                     desired_name, time_req,
 363                                     desired_mechs, cred_usage, handle, actual_mechs, time_rec);
 364         if (ret != GSS_S_COMPLETE) {
 365             HEIMDAL_MUTEX_destroy(&handle->cred_id_mutex);
 366             krb5_free_principal(context, handle->principal);
 367             free(handle);
 368             return (ret);
 369         }
 370     }
 371     ret = gss_create_empty_oid_set(minor_status, &handle->mechanisms);
 372     if (ret == GSS_S_COMPLETE)
 373         ret = gss_add_oid_set_member(minor_status, GSS_KRB5_MECHANISM,
 374                                      &handle->mechanisms);
 375     if (ret == GSS_S_COMPLETE)
 376         ret = _gsskrb5_inquire_cred(minor_status, (gss_cred_id_t)handle,
 377                                     NULL, time_rec, NULL, actual_mechs);
 378     if (ret != GSS_S_COMPLETE) {
 379         if (handle->mechanisms != NULL)
 380             gss_release_oid_set(NULL, &handle->mechanisms);
 381         HEIMDAL_MUTEX_destroy(&handle->cred_id_mutex);
 382         krb5_free_principal(context, handle->principal);
 383         free(handle);
 384         return (ret);
 385     }
 386     *minor_status = 0;
 387     if (time_rec) {
 388         ret = _gsskrb5_lifetime_left(minor_status,
 389                                      context,
 390                                      handle->lifetime,
 391                                      time_rec);
 392
 393         if (ret)
 394             return ret;
 395     }
 396     handle->usage = cred_usage;
 397     *output_cred_handle = (gss_cred_id_t)handle;
 398     return (GSS_S_COMPLETE);
 399 }