source/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;
  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
  47         if (!secrets_init()) {
  48                 DEBUG(1,("secrets_init failed\n"));
  49                 return NT_STATUS_LOGON_FAILURE;
  50         }
  51
  52         password_s = secrets_fetch_machine_password();
  53         if (!password_s) {
  54                 DEBUG(1,("failed to fetch machine password\n"));
  55                 return NT_STATUS_LOGON_FAILURE;
  56         }
  57
  58         password.data = password_s;
  59         password.length = strlen(password_s);
  60
  61         ret = krb5_init_context(&context);
  62         if (ret) {
  63                 DEBUG(1,("krb5_init_context failed (%s)\n", error_message(ret)));
  64                 return NT_STATUS_LOGON_FAILURE;
  65         }
  66
  67         ret = krb5_set_default_realm(context, ads->auth.realm);
  68         if (ret) {
  69                 DEBUG(1,("krb5_set_default_realm failed (%s)\n", error_message(ret)));
  70                 ads_destroy(&ads);
  71                 return NT_STATUS_LOGON_FAILURE;
  72         }
  73
  74         /* this whole process is far more complex than I would
  75            like. We have to go through all this to allow us to store
  76            the secret internally, instead of using /etc/krb5.keytab */
  77         ret = krb5_auth_con_init(context, &auth_context);
  78         if (ret) {
  79                 DEBUG(1,("krb5_auth_con_init failed (%s)\n", error_message(ret)));
  80                 return NT_STATUS_LOGON_FAILURE;
  81         }
  82
  83         fstrcpy(myname, global_myname());
  84         strlower(myname);
  85         asprintf(&host_princ_s, "HOST/%s@%s", myname, lp_realm());
  86         ret = krb5_parse_name(context, host_princ_s, &host_princ);
  87         if (ret) {
  88                 DEBUG(1,("krb5_parse_name(%s) failed (%s)\n", host_princ_s, error_message(ret)));
  89                 return NT_STATUS_LOGON_FAILURE;
  90         }
  91
  92         if (!(key = (krb5_keyblock *)malloc(sizeof(*key)))) {
  93                 return NT_STATUS_NO_MEMORY;
  94         }
  95
  96         if (create_kerberos_key_from_string(context, host_princ, &password, key)) {
  97                 SAFE_FREE(key);
  98                 return NT_STATUS_LOGON_FAILURE;
  99         }
 100
 101         krb5_auth_con_setuseruserkey(context, auth_context, key);
 102
 103         packet.length = ticket->length;
 104         packet.data = (krb5_pointer)ticket->data;
 105
 106 #if 0
 107         file_save("/tmp/ticket.dat", ticket->data, ticket->length);
 108 #endif
 109
 110         if ((ret = krb5_rd_req(context, &auth_context, &packet,
 111                                NULL, keytab, NULL, &tkt))) {
 112                 DEBUG(3,("krb5_rd_req with auth failed (%s)\n",
 113                          error_message(ret)));
 114                 return NT_STATUS_LOGON_FAILURE;
 115         }
 116
 117         get_auth_data_from_tkt(auth_data, tkt);
 118
 119 #if 0
 120         if (tkt->enc_part2) {
 121                 file_save("/tmp/authdata.dat",
 122                           tkt->enc_part2->authorization_data[0]->contents,
 123                           tkt->enc_part2->authorization_data[0]->length);
 124         }
 125 #endif
 126
 127         if ((ret = krb5_unparse_name(context, get_principal_from_tkt(tkt), principal))) {
 128                 DEBUG(3,("krb5_unparse_name failed (%s)\n",
 129                          error_message(ret)));
 130                 return NT_STATUS_LOGON_FAILURE;
 131         }
 132
 133         return NT_STATUS_OK;
 134 }
 135
 136 #endif