lib/krb5/verify_init.c

   1 /*
   2  * Copyright (c) 1997 - 2008 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_locl.h"
  35
  36 KRB5_LIB_FUNCTION void KRB5_LIB_CALL
  37 krb5_verify_init_creds_opt_init(krb5_verify_init_creds_opt *options)
  38 {
  39     memset (options, 0, sizeof(*options));
  40 }
  41
  42 KRB5_LIB_FUNCTION void KRB5_LIB_CALL
  43 krb5_verify_init_creds_opt_set_ap_req_nofail(krb5_verify_init_creds_opt *options,
  44                                              int ap_req_nofail)
  45 {
  46     options->flags |= KRB5_VERIFY_INIT_CREDS_OPT_AP_REQ_NOFAIL;
  47     options->ap_req_nofail = ap_req_nofail;
  48 }
  49
  50 /*
  51  *
  52  */
  53
  54 static krb5_boolean
  55 fail_verify_is_ok (krb5_context context,
  56                    krb5_verify_init_creds_opt *options)
  57 {
  58     if ((options->flags & KRB5_VERIFY_INIT_CREDS_OPT_AP_REQ_NOFAIL
  59          && options->ap_req_nofail != 0)
  60         || krb5_config_get_bool (context,
  61                                  NULL,
  62                                  "libdefaults",
  63                                  "verify_ap_req_nofail",
  64                                  NULL))
  65         return FALSE;
  66     else
  67         return TRUE;
  68 }
  69
  70 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
  71 krb5_verify_init_creds(krb5_context context,
  72                        krb5_creds *creds,
  73                        krb5_principal ap_req_server,
  74                        krb5_keytab ap_req_keytab,
  75                        krb5_ccache *ccache,
  76                        krb5_verify_init_creds_opt *options)
  77 {
  78     krb5_error_code ret;
  79     krb5_data req;
  80     krb5_ccache local_ccache = NULL;
  81     krb5_creds *new_creds = NULL;
  82     krb5_auth_context auth_context = NULL;
  83     krb5_principal server = NULL;
  84     krb5_keytab keytab = NULL;
  85
  86     krb5_data_zero (&req);
  87
  88     if (ap_req_server == NULL) {
  89         char local_hostname[MAXHOSTNAMELEN];
  90
  91         if (gethostname (local_hostname, sizeof(local_hostname)) < 0) {
  92             ret = errno;
  93             krb5_set_error_message (context, ret, "gethostname: %s",
  94                                     strerror(ret));
  95             return ret;
  96         }
  97
  98         ret = krb5_sname_to_principal (context,
  99                                        local_hostname,
 100                                        "host",
 101                                        KRB5_NT_SRV_HST,
 102                                        &server);
 103         if (ret)
 104             goto cleanup;
 105     } else
 106         server = ap_req_server;
 107
 108     if (ap_req_keytab == NULL) {
 109         ret = krb5_kt_default (context, &keytab);
 110         if (ret)
 111             goto cleanup;
 112     } else
 113         keytab = ap_req_keytab;
 114
 115     if (ccache && *ccache)
 116         local_ccache = *ccache;
 117     else {
 118         ret = krb5_cc_new_unique(context, krb5_cc_type_memory,
 119                                  NULL, &local_ccache);
 120         if (ret)
 121             goto cleanup;
 122         ret = krb5_cc_initialize (context,
 123                                   local_ccache,
 124                                   creds->client);
 125         if (ret)
 126             goto cleanup;
 127         ret = krb5_cc_store_cred (context,
 128                                   local_ccache,
 129                                   creds);
 130         if (ret)
 131             goto cleanup;
 132     }
 133
 134     if (!krb5_principal_compare (context, server, creds->server)) {
 135         krb5_creds match_cred;
 136
 137         memset (&match_cred, 0, sizeof(match_cred));
 138
 139         match_cred.client = creds->client;
 140         match_cred.server = server;
 141
 142         ret = krb5_get_credentials (context,
 143                                     0,
 144                                     local_ccache,
 145                                     &match_cred,
 146                                     &new_creds);
 147         if (ret) {
 148             if (fail_verify_is_ok (context, options))
 149                 ret = 0;
 150             goto cleanup;
 151         }
 152         creds = new_creds;
 153     }
 154
 155     ret = krb5_mk_req_extended (context,
 156                                 &auth_context,
 157                                 0,
 158                                 NULL,
 159                                 creds,
 160                                 &req);
 161
 162     krb5_auth_con_free (context, auth_context);
 163     auth_context = NULL;
 164
 165     if (ret)
 166         goto cleanup;
 167
 168     ret = krb5_rd_req (context,
 169                        &auth_context,
 170                        &req,
 171                        server,
 172                        keytab,
 173                        0,
 174                        NULL);
 175
 176     if (ret == KRB5_KT_NOTFOUND && fail_verify_is_ok (context, options))
 177         ret = 0;
 178 cleanup:
 179     if (auth_context)
 180         krb5_auth_con_free (context, auth_context);
 181     krb5_data_free (&req);
 182     if (new_creds != NULL)
 183         krb5_free_creds (context, new_creds);
 184     if (ap_req_server == NULL && server)
 185         krb5_free_principal (context, server);
 186     if (ap_req_keytab == NULL && keytab)
 187         krb5_kt_close (context, keytab);
 188     if (local_ccache != NULL
 189         &&
 190         (ccache == NULL
 191          || (ret != 0 && *ccache == NULL)))
 192         krb5_cc_destroy (context, local_ccache);
 193
 194     if (ret == 0 && ccache != NULL && *ccache == NULL)
 195         *ccache = local_ccache;
 196
 197     return ret;
 198 }
 199
 200 /**
 201  * Validate the newly fetch credential, see also krb5_verify_init_creds().
 202  *
 203  * @param context a Kerberos 5 context
 204  * @param creds the credentials to verify
 205  * @param client the client name to match up
 206  * @param ccache the credential cache to use
 207  * @param service a service name to use, used with
 208  *        krb5_sname_to_principal() to build a hostname to use to
 209  *        verify.
 210  *
 211  * @ingroup krb5_ccache
 212  */
 213
 214 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
 215 krb5_get_validated_creds(krb5_context context,
 216                          krb5_creds *creds,
 217                          krb5_principal client,
 218                          krb5_ccache ccache,
 219                          char *service)
 220 {
 221     krb5_verify_init_creds_opt vopt;
 222     krb5_principal server;
 223     krb5_error_code ret;
 224
 225     if (krb5_principal_compare(context, creds->client, client) != TRUE) {
 226         krb5_set_error_message(context, KRB5_PRINC_NOMATCH,
 227                                N_("Validation credentials and client "
 228                                   "doesn't match", ""));
 229         return KRB5_PRINC_NOMATCH;
 230     }
 231
 232     ret = krb5_sname_to_principal (context, NULL, service,
 233                                    KRB5_NT_SRV_HST, &server);
 234     if(ret)
 235         return ret;
 236
 237     krb5_verify_init_creds_opt_init(&vopt);
 238
 239     ret = krb5_verify_init_creds(context, creds, server, NULL, NULL, &vopt);
 240     krb5_free_principal(context, server);
 241
 242     return ret;
 243 }