source/auth/kerberos/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    Copyright (C) Luke Howard 2003
   7    Copyright (C) Guenther Deschner 2003
   8    Copyright (C) Jim McDonough (jmcd@us.ibm.com) 2003
   9    Copyright (C) Andrew Bartlett <abartlet@samba.org> 2004-2005
  10
  11    This program is free software; you can redistribute it and/or modify
  12    it under the terms of the GNU General Public License as published by
  13    the Free Software Foundation; either version 2 of the License, or
  14    (at your option) any later version.
  15
  16    This program is distributed in the hope that it will be useful,
  17    but WITHOUT ANY WARRANTY; without even the implied warranty of
  18    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19    GNU General Public License for more details.
  20
  21    You should have received a copy of the GNU General Public License
  22    along with this program; if not, write to the Free Software
  23    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  24 */
  25
  26 #include "includes.h"
  27 #include "system/kerberos.h"
  28 #include "auth/kerberos/kerberos.h"
  29 #include "auth/credentials/credentials.h"
  30 #include "auth/credentials/credentials_krb5.h"
  31
  32 /**********************************************************************************
  33  Verify an incoming ticket and parse out the principal name and
  34  authorization_data if available.
  35 ***********************************************************************************/
  36
  37  NTSTATUS ads_verify_ticket(TALLOC_CTX *mem_ctx,
  38                             struct smb_krb5_context *smb_krb5_context,
  39                             krb5_auth_context *auth_context,
  40                             struct cli_credentials *machine_account,
  41                             const char *service,
  42                             const DATA_BLOB *enc_ticket,
  43                             krb5_ticket **tkt,
  44                             DATA_BLOB *ap_rep,
  45                             krb5_keyblock **keyblock)
  46 {
  47         krb5_keyblock *local_keyblock;
  48         krb5_data packet;
  49         int ret;
  50         krb5_flags ap_req_options = 0;
  51         krb5_principal server;
  52         krb5_data packet_out;
  53
  54         struct keytab_container *keytab_container;
  55
  56         /*
  57          * TODO: Actually hook in the replay cache in Heimdal, then
  58          * re-add calls to setup a replay cache here, in our private
  59          * directory.  This will eventually prevent replay attacks
  60          */
  61
  62         packet.length = enc_ticket->length;
  63         packet.data = (krb5_pointer)enc_ticket->data;
  64
  65         /* Grab the keytab, however generated */
  66         ret = cli_credentials_get_keytab(machine_account, &keytab_container);
  67         if (ret) {
  68                 return NT_STATUS_CANT_ACCESS_DOMAIN_INFO;
  69         }
  70
  71         /* This ensures we lookup the correct entry in that keytab */
  72         ret = principal_from_credentials(mem_ctx, machine_account, smb_krb5_context,
  73                                          &server);
  74         if (ret == 0) {
  75                 ret = krb5_rd_req_return_keyblock(smb_krb5_context->krb5_context, auth_context, &packet,
  76                                                   server,
  77                                                   keytab_container->keytab, &ap_req_options, tkt,
  78                                                   &local_keyblock);
  79         }
  80
  81         if (ret) {
  82                 DEBUG(3,("ads_secrets_verify_ticket: failed to decrypt with error %s\n",
  83                          smb_get_krb5_error_message(smb_krb5_context->krb5_context, ret, mem_ctx)));
  84                 return NT_STATUS_LOGON_FAILURE;
  85         }
  86         *keyblock = local_keyblock;
  87
  88
  89         ret = krb5_mk_rep(smb_krb5_context->krb5_context, *auth_context, &packet_out);
  90         if (ret) {
  91                 krb5_free_ticket(smb_krb5_context->krb5_context, *tkt);
  92
  93                 DEBUG(3,("ads_verify_ticket: Failed to generate mutual authentication reply (%s)\n",
  94                          smb_get_krb5_error_message(smb_krb5_context->krb5_context, ret, mem_ctx)));
  95                 return NT_STATUS_LOGON_FAILURE;
  96         }
  97
  98         *ap_rep = data_blob_talloc(mem_ctx, packet_out.data, packet_out.length);
  99         krb5_free_data_contents(smb_krb5_context->krb5_context, &packet_out);
 100
 101         return NT_STATUS_OK;
 102 }