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 OM_uint32
  37 __gsskrb5_ccache_lifetime(OM_uint32 *minor_status,
  38                           krb5_context context,
  39                           krb5_ccache id,
  40                           krb5_principal principal,
  41                           OM_uint32 *lifetime)
  42 {
  43     krb5_creds in_cred, out_cred;
  44     krb5_const_realm realm;
  45     krb5_error_code kret;
  46
  47     memset(&in_cred, 0, sizeof(in_cred));
  48     in_cred.client = principal;
  49
  50     realm = krb5_principal_get_realm(context,  principal);
  51     if (realm == NULL) {
  52         _gsskrb5_clear_status ();
  53         *minor_status = KRB5_PRINC_NOMATCH; /* XXX */
  54         return GSS_S_FAILURE;
  55     }
  56
  57     kret = krb5_make_principal(context, &in_cred.server,
  58                                realm, KRB5_TGS_NAME, realm, NULL);
  59     if (kret) {
  60         *minor_status = kret;
  61         return GSS_S_FAILURE;
  62     }
  63
  64     kret = krb5_cc_retrieve_cred(context, id, 0, &in_cred, &out_cred);
  65     krb5_free_principal(context, in_cred.server);
  66     if (kret) {
  67         *minor_status = 0;
  68         *lifetime = 0;
  69         return GSS_S_COMPLETE;
  70     }
  71
  72     *lifetime = out_cred.times.endtime;
  73     krb5_free_cred_contents(context, &out_cred);
  74
  75     return GSS_S_COMPLETE;
  76 }
  77
  78
  79
  80
  81 static krb5_error_code
  82 get_keytab(krb5_context context, krb5_keytab *keytab)
  83 {
  84     krb5_error_code kret;
  85
  86     HEIMDAL_MUTEX_lock(&gssapi_keytab_mutex);
  87
  88     if (_gsskrb5_keytab != NULL) {
  89         char *name = NULL;
  90
  91         kret = krb5_kt_get_full_name(context, _gsskrb5_keytab, &name);
  92         if (kret == 0) {
  93             kret = krb5_kt_resolve(context, name, keytab);
  94             krb5_xfree(name);
  95         }
  96     } else
  97         kret = krb5_kt_default(context, keytab);
  98
  99     HEIMDAL_MUTEX_unlock(&gssapi_keytab_mutex);
 100
 101     return (kret);
 102 }
 103
 104 static OM_uint32 acquire_initiator_cred
 105                   (OM_uint32 * minor_status,
 106                    krb5_context context,
 107                    const gss_OID credential_type,
 108                    void *credential_data,
 109                    const gss_name_t desired_name,
 110                    OM_uint32 time_req,
 111                    const gss_OID desired_mech,
 112                    gss_cred_usage_t cred_usage,
 113                    gsskrb5_cred handle
 114                   )
 115 {
 116     OM_uint32 ret;
 117     krb5_creds cred;
 118     krb5_principal def_princ;
 119     krb5_get_init_creds_opt *opt;
 120     krb5_ccache ccache;
 121     krb5_keytab keytab;
 122     krb5_error_code kret;
 123
 124     keytab = NULL;
 125     ccache = NULL;
 126     def_princ = NULL;
 127     ret = GSS_S_FAILURE;
 128     memset(&cred, 0, sizeof(cred));
 129
 130     /*
 131      * If we have a preferred principal, lets try to find it in all
 132      * caches, otherwise, fall back to default cache, ignore all
 133      * errors while searching.
 134      */
 135
 136     if (credential_type != GSS_C_NO_OID &&
 137         !gss_oid_equal(credential_type, GSS_C_CRED_PASSWORD)) {
 138         kret = KRB5_NOCREDS_SUPPLIED; /* XXX */
 139         goto end;
 140     }
 141
 142     if (handle->principal) {
 143         kret = krb5_cc_cache_match (context,
 144                                     handle->principal,
 145                                     &ccache);
 146         if (kret == 0) {
 147             ret = GSS_S_COMPLETE;
 148             goto found;
 149         }
 150     }
 151
 152     if (ccache == NULL) {
 153         kret = krb5_cc_default(context, &ccache);
 154         if (kret)
 155             goto end;
 156     }
 157     kret = krb5_cc_get_principal(context, ccache, &def_princ);
 158     if (kret != 0) {
 159         /* we'll try to use a keytab below */
 160         krb5_cc_close(context, ccache);
 161         def_princ = NULL;
 162         kret = 0;
 163     } else if (handle->principal == NULL)  {
 164         kret = krb5_copy_principal(context, def_princ, &handle->principal);
 165         if (kret)
 166             goto end;
 167     } else if (handle->principal != NULL &&
 168                krb5_principal_compare(context, handle->principal,
 169                                       def_princ) == FALSE) {
 170         krb5_free_principal(context, def_princ);
 171         def_princ = NULL;
 172         krb5_cc_close(context, ccache);
 173         ccache = NULL;
 174     }
 175     if (def_princ == NULL) {
 176         /* We have no existing credentials cache,
 177          * so attempt to get a TGT using a keytab.
 178          */
 179         if (handle->principal == NULL) {
 180             kret = krb5_get_default_principal(context, &handle->principal);
 181             if (kret)
 182                 goto end;
 183         }
 184         kret = krb5_get_init_creds_opt_alloc(context, &opt);
 185         if (kret)
 186             goto end;
 187         if (credential_type != GSS_C_NO_OID &&
 188             gss_oid_equal(credential_type, GSS_C_CRED_PASSWORD)) {
 189             gss_buffer_t password = (gss_buffer_t)credential_data;
 190
 191             /* XXX are we requiring password to be NUL terminated? */
 192
 193             kret = krb5_get_init_creds_password(context, &cred,
 194                                                 handle->principal,
 195                                                 password->value,
 196                                                 NULL, NULL, 0, NULL, opt);
 197         } else {
 198             kret = get_keytab(context, &keytab);
 199             if (kret) {
 200                 krb5_get_init_creds_opt_free(context, opt);
 201                 goto end;
 202             }
 203             kret = krb5_get_init_creds_keytab(context, &cred,
 204                                               handle->principal, keytab,
 205                                               0, NULL, opt);
 206         }
 207         krb5_get_init_creds_opt_free(context, opt);
 208         if (kret)
 209             goto end;
 210         kret = krb5_cc_new_unique(context, krb5_cc_type_memory,
 211                                   NULL, &ccache);
 212         if (kret)
 213             goto end;
 214         kret = krb5_cc_initialize(context, ccache, cred.client);
 215         if (kret) {
 216             krb5_cc_destroy(context, ccache);
 217             goto end;
 218         }
 219         kret = krb5_cc_store_cred(context, ccache, &cred);
 220         if (kret) {
 221             krb5_cc_destroy(context, ccache);
 222             goto end;
 223         }
 224         handle->lifetime = cred.times.endtime;
 225         handle->cred_flags |= GSS_CF_DESTROY_CRED_ON_RELEASE;
 226     } else {
 227
 228         ret = __gsskrb5_ccache_lifetime(minor_status,
 229                                         context,
 230                                         ccache,
 231                                         handle->principal,
 232                                         &handle->lifetime);
 233         if (ret != GSS_S_COMPLETE) {
 234             krb5_cc_close(context, ccache);
 235             goto end;
 236         }
 237         kret = 0;
 238     }
 239  found:
 240     handle->ccache = ccache;
 241     ret = GSS_S_COMPLETE;
 242
 243 end:
 244     if (cred.client != NULL)
 245         krb5_free_cred_contents(context, &cred);
 246     if (def_princ != NULL)
 247         krb5_free_principal(context, def_princ);
 248     if (keytab != NULL)
 249         krb5_kt_close(context, keytab);
 250     if (ret != GSS_S_COMPLETE && kret != 0)
 251         *minor_status = kret;
 252     return (ret);
 253 }
 254
 255 static OM_uint32 acquire_acceptor_cred
 256                   (OM_uint32 * minor_status,
 257                    krb5_context context,
 258                    const gss_OID credential_type,
 259                    void *credential_data,
 260                    const gss_name_t desired_name,
 261                    OM_uint32 time_req,
 262                    const gss_OID desired_mech,
 263                    gss_cred_usage_t cred_usage,
 264                    gsskrb5_cred handle
 265                   )
 266 {
 267     OM_uint32 ret;
 268     krb5_error_code kret;
 269
 270     ret = GSS_S_FAILURE;
 271
 272     if (credential_type != GSS_C_NO_OID) {
 273         kret = EINVAL;
 274         goto end;
 275     }
 276
 277     kret = get_keytab(context, &handle->keytab);
 278     if (kret)
 279         goto end;
 280
 281     /* check that the requested principal exists in the keytab */
 282     if (handle->principal) {
 283         krb5_keytab_entry entry;
 284
 285         kret = krb5_kt_get_entry(context, handle->keytab,
 286                                  handle->principal, 0, 0, &entry);
 287         if (kret)
 288             goto end;
 289         krb5_kt_free_entry(context, &entry);
 290         ret = GSS_S_COMPLETE;
 291     } else {
 292         /*
 293          * Check if there is at least one entry in the keytab before
 294          * declaring it as an useful keytab.
 295          */
 296         krb5_keytab_entry tmp;
 297         krb5_kt_cursor c;
 298
 299         kret = krb5_kt_start_seq_get (context, handle->keytab, &c);
 300         if (kret)
 301             goto end;
 302         if (krb5_kt_next_entry(context, handle->keytab, &tmp, &c) == 0) {
 303             krb5_kt_free_entry(context, &tmp);
 304             ret = GSS_S_COMPLETE; /* ok found one entry */
 305         }
 306         krb5_kt_end_seq_get (context, handle->keytab, &c);
 307     }
 308 end:
 309     if (ret != GSS_S_COMPLETE) {
 310         if (handle->keytab != NULL)
 311             krb5_kt_close(context, handle->keytab);
 312         if (kret != 0) {
 313             *minor_status = kret;
 314         }
 315     }
 316     return (ret);
 317 }
 318
 319 OM_uint32 GSSAPI_CALLCONV _gsskrb5_acquire_cred
 320 (OM_uint32 * minor_status,
 321  const gss_name_t desired_name,
 322  OM_uint32 time_req,
 323  const gss_OID_set desired_mechs,
 324  gss_cred_usage_t cred_usage,
 325  gss_cred_id_t * output_cred_handle,
 326  gss_OID_set * actual_mechs,
 327  OM_uint32 * time_rec
 328     )
 329 {
 330     OM_uint32 ret;
 331
 332     if (desired_mechs) {
 333         int present = 0;
 334
 335         ret = gss_test_oid_set_member(minor_status, GSS_KRB5_MECHANISM,
 336                                       desired_mechs, &present);
 337         if (ret)
 338             return ret;
 339         if (!present) {
 340             *minor_status = 0;
 341             return GSS_S_BAD_MECH;
 342         }
 343     }
 344
 345     ret = _gsskrb5_acquire_cred_ex(minor_status,
 346                                    desired_name,
 347                                    GSS_C_NO_OID,
 348                                    NULL,
 349                                    time_req,
 350                                    GSS_KRB5_MECHANISM,
 351                                    cred_usage,
 352                                    output_cred_handle);
 353     if (ret)
 354         return ret;
 355
 356
 357     ret = _gsskrb5_inquire_cred(minor_status, *output_cred_handle,
 358                                 NULL, time_rec, NULL, actual_mechs);
 359     if (ret) {
 360         OM_uint32 tmp;
 361         _gsskrb5_release_cred(&tmp, output_cred_handle);
 362     }
 363
 364     return ret;
 365 }
 366
 367 OM_uint32 GSSAPI_CALLCONV _gsskrb5_acquire_cred_ex
 368 (OM_uint32 * minor_status,
 369  const gss_name_t desired_name,
 370  const gss_OID credential_type,
 371  void *credential_data,
 372  OM_uint32 time_req,
 373  const gss_OID desired_mech,
 374  gss_cred_usage_t cred_usage,
 375  gss_cred_id_t * output_cred_handle
 376     )
 377 {
 378     krb5_context context;
 379     gsskrb5_cred handle;
 380     OM_uint32 ret;
 381
 382     cred_usage &= GSS_C_OPTION_MASK;
 383
 384     if (cred_usage != GSS_C_ACCEPT && cred_usage != GSS_C_INITIATE && cred_usage != GSS_C_BOTH) {
 385         *minor_status = GSS_KRB5_S_G_BAD_USAGE;
 386         return GSS_S_FAILURE;
 387     }
 388
 389     GSSAPI_KRB5_INIT(&context);
 390
 391     *output_cred_handle = NULL;
 392
 393     handle = calloc(1, sizeof(*handle));
 394     if (handle == NULL) {
 395         *minor_status = ENOMEM;
 396         return (GSS_S_FAILURE);
 397     }
 398
 399     HEIMDAL_MUTEX_init(&handle->cred_id_mutex);
 400
 401     if (desired_name != GSS_C_NO_NAME) {
 402         ret = _gsskrb5_canon_name(minor_status, context, 1, NULL,
 403                                   desired_name, &handle->principal);
 404         if (ret) {
 405             HEIMDAL_MUTEX_destroy(&handle->cred_id_mutex);
 406             free(handle);
 407             return ret;
 408         }
 409     }
 410     if (cred_usage == GSS_C_INITIATE || cred_usage == GSS_C_BOTH) {
 411         ret = acquire_initiator_cred(minor_status, context,
 412                                      credential_type, credential_data,
 413                                      desired_name, time_req,
 414                                      desired_mech, cred_usage, handle);
 415         if (ret != GSS_S_COMPLETE) {
 416             HEIMDAL_MUTEX_destroy(&handle->cred_id_mutex);
 417             krb5_free_principal(context, handle->principal);
 418             free(handle);
 419             return (ret);
 420         }
 421     }
 422     if (cred_usage == GSS_C_ACCEPT || cred_usage == GSS_C_BOTH) {
 423         ret = acquire_acceptor_cred(minor_status, context,
 424                                     credential_type, credential_data,
 425                                     desired_name, time_req,
 426                                     desired_mech, cred_usage, handle);
 427         if (ret != GSS_S_COMPLETE) {
 428             HEIMDAL_MUTEX_destroy(&handle->cred_id_mutex);
 429             krb5_free_principal(context, handle->principal);
 430             free(handle);
 431             return (ret);
 432         }
 433     }
 434     ret = gss_create_empty_oid_set(minor_status, &handle->mechanisms);
 435     if (ret == GSS_S_COMPLETE)
 436         ret = gss_add_oid_set_member(minor_status, GSS_KRB5_MECHANISM,
 437                                      &handle->mechanisms);
 438     if (ret != GSS_S_COMPLETE) {
 439         if (handle->mechanisms != NULL)
 440             gss_release_oid_set(NULL, &handle->mechanisms);
 441         HEIMDAL_MUTEX_destroy(&handle->cred_id_mutex);
 442         krb5_free_principal(context, handle->principal);
 443         free(handle);
 444         return (ret);
 445     }
 446     handle->usage = cred_usage;
 447     *minor_status = 0;
 448     *output_cred_handle = (gss_cred_id_t)handle;
 449     return (GSS_S_COMPLETE);
 450 }