source3/libads/kerberos_verify.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    kerberos utility library
   4    Copyright (C) Andrew Tridgell 2001
   5    Copyright (C) Remus Koos 2001
   6
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 2 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program; if not, write to the Free Software
  20    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  21 */
  22
  23 #include "includes.h"
  24
  25 #ifdef HAVE_KRB5
  26
  27 /*
  28   verify an incoming ticket and parse out the principal name and
  29   authorization_data if available
  30 */
  31 NTSTATUS ads_verify_ticket(ADS_STRUCT *ads, const DATA_BLOB *ticket,
  32                            char **principal, DATA_BLOB *auth_data)
  33 {
  34         krb5_context context;
  35         krb5_auth_context auth_context = NULL;
  36         krb5_keytab keytab = NULL;
  37         krb5_data packet;
  38         krb5_ticket *tkt = NULL;
  39         int ret, i;
  40         krb5_keyblock * key;
  41         krb5_principal host_princ;
  42         char *host_princ_s;
  43         fstring myname;
  44         char *password_s;
  45         krb5_data password;
  46         krb5_enctype *enctypes = NULL;
  47         BOOL auth_ok = False;
  48
  49         if (!secrets_init()) {
  50                 DEBUG(1,("secrets_init failed\n"));
  51                 return NT_STATUS_LOGON_FAILURE;
  52         }
  53
  54         password_s = secrets_fetch_machine_password();
  55         if (!password_s) {
  56                 DEBUG(1,("failed to fetch machine password\n"));
  57                 return NT_STATUS_LOGON_FAILURE;
  58         }
  59
  60         password.data = password_s;
  61         password.length = strlen(password_s);
  62
  63         ret = krb5_init_context(&context);
  64         if (ret) {
  65                 DEBUG(1,("krb5_init_context failed (%s)\n", error_message(ret)));
  66                 return NT_STATUS_LOGON_FAILURE;
  67         }
  68
  69         ret = krb5_set_default_realm(context, ads->auth.realm);
  70         if (ret) {
  71                 DEBUG(1,("krb5_set_default_realm failed (%s)\n", error_message(ret)));
  72                 return NT_STATUS_LOGON_FAILURE;
  73         }
  74
  75         /* this whole process is far more complex than I would
  76            like. We have to go through all this to allow us to store
  77            the secret internally, instead of using /etc/krb5.keytab */
  78         ret = krb5_auth_con_init(context, &auth_context);
  79         if (ret) {
  80                 DEBUG(1,("krb5_auth_con_init failed (%s)\n", error_message(ret)));
  81                 return NT_STATUS_LOGON_FAILURE;
  82         }
  83
  84         fstrcpy(myname, global_myname());
  85         strlower(myname);
  86         asprintf(&host_princ_s, "HOST/%s@%s", myname, lp_realm());
  87         ret = krb5_parse_name(context, host_princ_s, &host_princ);
  88         if (ret) {
  89                 DEBUG(1,("krb5_parse_name(%s) failed (%s)\n", host_princ_s, error_message(ret)));
  90                 return NT_STATUS_LOGON_FAILURE;
  91         }
  92
  93         if (!(key = (krb5_keyblock *)malloc(sizeof(*key)))) {
  94                 return NT_STATUS_NO_MEMORY;
  95         }
  96
  97         if ((ret = get_kerberos_allowed_etypes(context, &enctypes))) {
  98                 DEBUG(1,("krb5_get_permitted_enctypes failed (%s)\n",
  99                          error_message(ret)));
 100                 return NT_STATUS_LOGON_FAILURE;
 101         }
 102
 103         /* we need to setup a auth context with each possible encoding type in turn */
 104         for (i=0;enctypes[i];i++) {
 105                 if (create_kerberos_key_from_string(context, host_princ, &password, key, enctypes[i])) {
 106                         continue;
 107                 }
 108
 109                 krb5_auth_con_setuseruserkey(context, auth_context, key);
 110
 111                 packet.length = ticket->length;
 112                 packet.data = (krb5_pointer)ticket->data;
 113
 114                 if (!(ret = krb5_rd_req(context, &auth_context, &packet,
 115                                        NULL, keytab, NULL, &tkt))) {
 116                         free_kerberos_etypes(context, enctypes);
 117                         auth_ok = True;
 118                         break;
 119                 }
 120         }
 121
 122         if (!auth_ok) {
 123                 DEBUG(3,("krb5_rd_req with auth failed (%s)\n",
 124                          error_message(ret)));
 125                 SAFE_FREE(key);
 126                 return NT_STATUS_LOGON_FAILURE;
 127         }
 128
 129 #if 0
 130         file_save("/tmp/ticket.dat", ticket->data, ticket->length);
 131 #endif
 132
 133         get_auth_data_from_tkt(auth_data, tkt);
 134
 135 #if 0
 136         if (tkt->enc_part2) {
 137                 file_save("/tmp/authdata.dat",
 138                           tkt->enc_part2->authorization_data[0]->contents,
 139                           tkt->enc_part2->authorization_data[0]->length);
 140         }
 141 #endif
 142
 143         if ((ret = krb5_unparse_name(context, get_principal_from_tkt(tkt),
 144                                      principal))) {
 145                 DEBUG(3,("krb5_unparse_name failed (%s)\n",
 146                          error_message(ret)));
 147                 return NT_STATUS_LOGON_FAILURE;
 148         }
 149
 150         return NT_STATUS_OK;
 151 }
 152
 153 #endif