source/auth/auth_server.c

   1 /*
   2    Unix SMB/Netbios implementation.
   3    Version 1.9.
   4    Authenticate to a remote server
   5    Copyright (C) Andrew Tridgell 1992-1998
   6    Copyright (C) Andrew Bartlett 2001
   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 extern pstring global_myname;
  26
  27 /****************************************************************************
  28  Return the client state structure.
  29 ****************************************************************************/
  30
  31 struct cli_state *server_client(void)
  32 {
  33         static struct cli_state pw_cli;
  34         return &pw_cli;
  35 }
  36
  37 /****************************************************************************
  38  Support for server level security.
  39 ****************************************************************************/
  40
  41 struct cli_state *server_cryptkey(void)
  42 {
  43         struct cli_state *cli;
  44         fstring desthost;
  45         struct in_addr dest_ip;
  46         char *p, *pserver;
  47         BOOL connected_ok = False;
  48
  49         cli = server_client();
  50
  51         if (!cli_initialise(cli))
  52                 return NULL;
  53
  54         pserver = strdup(lp_passwordserver());
  55         p = pserver;
  56
  57         while(next_token( &p, desthost, LIST_SEP, sizeof(desthost))) {
  58                 standard_sub_basic(desthost);
  59                 strupper(desthost);
  60
  61                 if(!resolve_name( desthost, &dest_ip, 0x20)) {
  62                         DEBUG(1,("server_cryptkey: Can't resolve address for %s\n",desthost));
  63                         continue;
  64                 }
  65
  66                 if (ismyip(dest_ip)) {
  67                         DEBUG(1,("Password server loop - disabling password server %s\n",desthost));
  68                         continue;
  69                 }
  70
  71                 if (cli_connect(cli, desthost, &dest_ip)) {
  72                         DEBUG(3,("connected to password server %s\n",desthost));
  73                         connected_ok = True;
  74                         break;
  75                 }
  76         }
  77
  78         SAFE_FREE(pserver);
  79
  80         if (!connected_ok) {
  81                 DEBUG(0,("password server not available\n"));
  82                 cli_shutdown(cli);
  83                 return NULL;
  84         }
  85
  86         if (!attempt_netbios_session_request(cli, global_myname, desthost, &dest_ip))
  87                 return NULL;
  88
  89         DEBUG(3,("got session\n"));
  90
  91         if (!cli_negprot(cli)) {
  92                 DEBUG(1,("%s rejected the negprot\n",desthost));
  93                 cli_shutdown(cli);
  94                 return NULL;
  95         }
  96
  97         if (cli->protocol < PROTOCOL_LANMAN2 ||
  98             !(cli->sec_mode & 1)) {
  99                 DEBUG(1,("%s isn't in user level security mode\n",desthost));
 100                 cli_shutdown(cli);
 101                 return NULL;
 102         }
 103
 104         DEBUG(3,("password server OK\n"));
 105
 106         return cli;
 107 }
 108
 109
 110 /****************************************************************************
 111  Check for a valid username and password in security=server mode.
 112   - Validate a password with the password server.
 113 ****************************************************************************/
 114
 115 NTSTATUS check_server_security(const auth_usersupplied_info *user_info, auth_serversupplied_info *server_info)
 116 {
 117         struct cli_state *cli;
 118         static unsigned char badpass[24];
 119         static fstring baduser;
 120         static BOOL tested_password_server = False;
 121         static BOOL bad_password_server = False;
 122         NTSTATUS nt_status = NT_STATUS_LOGON_FAILURE;
 123
 124         cli = server_client();
 125
 126         if (!cli->initialised) {
 127                 DEBUG(1,("password server %s is not connected\n", cli->desthost));
 128                 return(NT_STATUS_LOGON_FAILURE);
 129         }
 130
 131         if(badpass[0] == 0)
 132                 memset(badpass, 0x1f, sizeof(badpass));
 133
 134         if((user_info->nt_resp.len == sizeof(badpass)) &&
 135            !memcmp(badpass, user_info->nt_resp.buffer, sizeof(badpass))) {
 136                 /*
 137                  * Very unlikely, our random bad password is the same as the users
 138                  * password.
 139                  */
 140                 memset(badpass, badpass[0]+1, sizeof(badpass));
 141         }
 142
 143         if(baduser[0] == 0) {
 144                 fstrcpy(baduser, INVALID_USER_PREFIX);
 145                 fstrcat(baduser, global_myname);
 146         }
 147
 148         /*
 149          * Attempt a session setup with a totally incorrect password.
 150          * If this succeeds with the guest bit *NOT* set then the password
 151          * server is broken and is not correctly setting the guest bit. We
 152          * need to detect this as some versions of NT4.x are broken. JRA.
 153          */
 154
 155         /* I sure as hell hope that there arn't servers out there that take
 156          * NTLMv2 and have this bug, as we don't test for that...
 157          *  - abartlet@samba.org
 158          */
 159
 160         if ((!tested_password_server) && (lp_paranoid_server_security())) {
 161                 if (cli_session_setup(cli, baduser, (char *)badpass, sizeof(badpass),
 162                                         (char *)badpass, sizeof(badpass), user_info->domain.str)) {
 163
 164                         /*
 165                          * We connected to the password server so we
 166                          * can say we've tested it.
 167                          */
 168                         tested_password_server = True;
 169
 170                         if ((SVAL(cli->inbuf,smb_vwv2) & 1) == 0) {
 171                                 DEBUG(0,("server_validate: password server %s allows users as non-guest \
 172 with a bad password.\n", cli->desthost));
 173                                 DEBUG(0,("server_validate: This is broken (and insecure) behaviour. Please do not \
 174 use this machine as the password server.\n"));
 175                                 cli_ulogoff(cli);
 176
 177                                 /*
 178                                  * Password server has the bug.
 179                                  */
 180                                 bad_password_server = True;
 181                                 return NT_STATUS_LOGON_FAILURE;
 182                         }
 183                         cli_ulogoff(cli);
 184                 }
 185         } else {
 186
 187                 /*
 188                  * We have already tested the password server.
 189                  * Fail immediately if it has the bug.
 190                  */
 191
 192                 if(bad_password_server) {
 193                         DEBUG(0,("server_validate: [1] password server %s allows users as non-guest \
 194 with a bad password.\n", cli->desthost));
 195                         DEBUG(0,("server_validate: [1] This is broken (and insecure) behaviour. Please do not \
 196 use this machine as the password server.\n"));
 197                         return NT_STATUS_LOGON_FAILURE;
 198                 }
 199         }
 200
 201         /*
 202          * Now we know the password server will correctly set the guest bit, or is
 203          * not guest enabled, we can try with the real password.
 204          */
 205
 206         if (!cli_session_setup(cli, user_info->smb_username.str,
 207                                (char *)user_info->lm_resp.buffer,
 208                                user_info->lm_resp.len,
 209                                (char *)user_info->nt_resp.buffer,
 210                                user_info->nt_resp.len,
 211                                user_info->domain.str)) {
 212                 DEBUG(1,("password server %s rejected the password\n", cli->desthost));
 213                 /* Make this cli_nt_error() when the conversion is in */
 214                 nt_status = cli_nt_error(cli);
 215         } else {
 216                 nt_status = NT_STATUS_OK;
 217         }
 218
 219         /* if logged in as guest then reject */
 220         if ((SVAL(cli->inbuf,smb_vwv2) & 1) != 0) {
 221                 DEBUG(1,("password server %s gave us guest only\n", cli->desthost));
 222                 nt_status = NT_STATUS_LOGON_FAILURE;
 223         }
 224
 225         cli_ulogoff(cli);
 226
 227         return(nt_status);
 228 }