source3/auth/auth_rhosts.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    Main SMB reply routines
   4    Copyright (C) Andrew Tridgell 1992-1998
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 2 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program; if not, write to the Free Software
  18    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  19 */
  20
  21 #include "includes.h"
  22
  23 #undef DBGC_CLASS
  24 #define DBGC_CLASS DBGC_AUTH
  25
  26 /****************************************************************************
  27  Read the a hosts.equiv or .rhosts file and check if it
  28  allows this user from this machine.
  29 ****************************************************************************/
  30
  31 static BOOL check_user_equiv(const char *user, const char *remote, const char *equiv_file)
  32 {
  33   int plus_allowed = 1;
  34   char *file_host;
  35   char *file_user;
  36   char **lines = file_lines_load(equiv_file, NULL);
  37   int i;
  38
  39   DEBUG(5, ("check_user_equiv %s %s %s\n", user, remote, equiv_file));
  40   if (! lines) return False;
  41   for (i=0; lines[i]; i++) {
  42     char *buf = lines[i];
  43     trim_string(buf," "," ");
  44
  45     if (buf[0] != '#' && buf[0] != '\n')
  46     {
  47       BOOL is_group = False;
  48       int plus = 1;
  49       char *bp = buf;
  50       if (strcmp(buf, "NO_PLUS\n") == 0)
  51       {
  52         DEBUG(6, ("check_user_equiv NO_PLUS\n"));
  53         plus_allowed = 0;
  54       }
  55       else {
  56         if (buf[0] == '+')
  57         {
  58           bp++;
  59           if (*bp == '\n' && plus_allowed)
  60           {
  61             /* a bare plus means everbody allowed */
  62             DEBUG(6, ("check_user_equiv everybody allowed\n"));
  63             file_lines_free(lines);
  64             return True;
  65           }
  66         }
  67         else if (buf[0] == '-')
  68         {
  69           bp++;
  70           plus = 0;
  71         }
  72         if (*bp == '@')
  73         {
  74           is_group = True;
  75           bp++;
  76         }
  77         file_host = strtok(bp, " \t\n");
  78         file_user = strtok(NULL, " \t\n");
  79         DEBUG(7, ("check_user_equiv %s %s\n", file_host ? file_host : "(null)",
  80                  file_user ? file_user : "(null)" ));
  81         if (file_host && *file_host)
  82         {
  83           BOOL host_ok = False;
  84
  85 #if defined(HAVE_NETGROUP) && defined(HAVE_YP_GET_DEFAULT_DOMAIN)
  86           if (is_group)
  87             {
  88               static char *mydomain = NULL;
  89               if (!mydomain)
  90                 yp_get_default_domain(&mydomain);
  91               if (mydomain && innetgr(file_host,remote,user,mydomain))
  92                 host_ok = True;
  93             }
  94 #else
  95           if (is_group)
  96             {
  97               DEBUG(1,("Netgroups not configured\n"));
  98               continue;
  99             }
 100 #endif
 101
 102           /* is it this host */
 103           /* the fact that remote has come from a call of gethostbyaddr
 104            * means that it may have the fully qualified domain name
 105            * so we could look up the file version to get it into
 106            * a canonical form, but I would rather just type it
 107            * in full in the equiv file
 108            */
 109           if (!host_ok && !is_group && strequal(remote, file_host))
 110             host_ok = True;
 111
 112           if (!host_ok)
 113             continue;
 114
 115           /* is it this user */
 116           if (file_user == 0 || strequal(user, file_user))
 117             {
 118               DEBUG(5, ("check_user_equiv matched %s%s %s\n",
 119                         (plus ? "+" : "-"), file_host,
 120                         (file_user ? file_user : "")));
 121               file_lines_free(lines);
 122               return (plus ? True : False);
 123             }
 124         }
 125       }
 126     }
 127   }
 128   file_lines_free(lines);
 129   return False;
 130 }
 131
 132
 133 /****************************************************************************
 134 check for a possible hosts equiv or rhosts entry for the user
 135 ****************************************************************************/
 136
 137 static BOOL check_hosts_equiv(struct passwd *pass)
 138 {
 139   char *fname = NULL;
 140
 141   if (!pass)
 142     return(False);
 143
 144   fname = lp_hosts_equiv();
 145
 146   /* note: don't allow hosts.equiv on root */
 147   if (fname && *fname && (pass->pw_uid != 0)) {
 148           if (check_user_equiv(pass->pw_name,client_name(),fname))
 149                   return(True);
 150   }
 151
 152   return(False);
 153 }
 154
 155
 156 /****************************************************************************
 157  Check for a valid .rhosts/hosts.equiv entry for this user
 158 ****************************************************************************/
 159
 160 static NTSTATUS check_hostsequiv_security(const struct auth_context *auth_context,
 161                                           void *my_private_data,
 162                                           TALLOC_CTX *mem_ctx,
 163                                           const auth_usersupplied_info *user_info,
 164                                           auth_serversupplied_info **server_info)
 165 {
 166         NTSTATUS nt_status = NT_STATUS_LOGON_FAILURE;
 167         struct passwd *pass = Get_Pwnam(user_info->internal_username.str);
 168
 169         if (pass) {
 170                 if (check_hosts_equiv(pass)) {
 171                         nt_status = NT_STATUS_OK;
 172                         make_server_info_pw(server_info, pass);
 173                 }
 174         } else {
 175                 nt_status = NT_STATUS_NO_SUCH_USER;
 176         }
 177
 178         return nt_status;
 179 }
 180
 181 /* module initialisation */
 182 NTSTATUS auth_init_hostsequiv(struct auth_context *auth_context, const char* param, auth_methods **auth_method)
 183 {
 184         if (!make_auth_methods(auth_context, auth_method)) {
 185                 return NT_STATUS_NO_MEMORY;
 186         }
 187
 188         (*auth_method)->auth = check_hostsequiv_security;
 189         return NT_STATUS_OK;
 190 }
 191
 192
 193 /****************************************************************************
 194  Check for a valid .rhosts/hosts.equiv entry for this user
 195 ****************************************************************************/
 196
 197 static NTSTATUS check_rhosts_security(const struct auth_context *auth_context,
 198                                       void *my_private_data,
 199                                       TALLOC_CTX *mem_ctx,
 200                                       const auth_usersupplied_info *user_info,
 201                                       auth_serversupplied_info **server_info)
 202 {
 203         NTSTATUS nt_status = NT_STATUS_LOGON_FAILURE;
 204         struct passwd *pass = Get_Pwnam(user_info->internal_username.str);
 205         pstring rhostsfile;
 206
 207         if (pass) {
 208                 char *home = pass->pw_dir;
 209                 if (home) {
 210                         slprintf(rhostsfile, sizeof(rhostsfile)-1, "%s/.rhosts", home);
 211                         become_root();
 212                         if (check_user_equiv(pass->pw_name,client_name(),rhostsfile)) {
 213                                 nt_status = NT_STATUS_OK;
 214                                 make_server_info_pw(server_info, pass);
 215                         }
 216                         unbecome_root();
 217                 }
 218         } else {
 219                 nt_status = NT_STATUS_NO_SUCH_USER;
 220         }
 221
 222         return nt_status;
 223 }
 224
 225 /* module initialisation */
 226 NTSTATUS auth_init_rhosts(struct auth_context *auth_context, const char *param, auth_methods **auth_method)
 227 {
 228         if (!make_auth_methods(auth_context, auth_method)) {
 229                 return NT_STATUS_NO_MEMORY;
 230         }
 231
 232         (*auth_method)->auth = check_rhosts_security;
 233         return NT_STATUS_OK;
 234 }