src/modules/extra/m_ldapauth.cpp

   1 /*       +------------------------------------+
   2  *       | Inspire Internet Relay Chat Daemon |
   3  *       +------------------------------------+
   4  *
   5  *  InspIRCd: (C) 2002-2010 InspIRCd Development Team
   6  * See: http://wiki.inspircd.org/Credits
   7  *
   8  * This program is free but copyrighted software; see
   9  *            the file COPYING for details.
  10  *
  11  * ---------------------------------------------------
  12  *
  13  * Taken from the UnrealIRCd 4.0 SVN version, based on
  14  * InspIRCd 1.1.x.
  15  *
  16  * UnrealIRCd 4.0 (C) 2007 Carsten Valdemar Munk
  17  * This program is free but copyrighted software; see
  18  *          the file COPYING for details.
  19  *
  20  * ---------------------------------------------------
  21  * Heavily based on SQLauth
  22  */
  23
  24 #include "inspircd.h"
  25 #include "users.h"
  26 #include "channels.h"
  27 #include "modules.h"
  28
  29 #include <ldap.h>
  30
  31 #ifdef WINDOWS
  32 # pragma comment(lib, "ldap.lib")
  33 # pragma comment(lib, "lber.lib")
  34 #endif
  35
  36 /* $ModDesc: Allow/Deny connections based upon answer from LDAP server */
  37 /* $LinkerFlags: -lldap */
  38
  39 class ModuleLDAPAuth : public Module
  40 {
  41         LocalIntExt ldapAuthed;
  42         std::string base;
  43         std::string attribute;
  44         std::string ldapserver;
  45         std::string allowpattern;
  46         std::string killreason;
  47         std::string username;
  48         std::string password;
  49         std::vector<std::string> whitelistedcidrs;
  50         int searchscope;
  51         bool verbose;
  52         bool useusername;
  53         LDAP *conn;
  54
  55 public:
  56         ModuleLDAPAuth() : ldapAuthed("ldapauth", this)
  57         {
  58                 conn = NULL;
  59         }
  60
  61         void init()
  62         {
  63                 Implementation eventlist[] = { I_OnCheckReady, I_OnRehash, I_OnUserRegister };
  64                 ServerInstance->Modules->Attach(eventlist, this, 3);
  65                 OnRehash(NULL);
  66         }
  67
  68         ~ModuleLDAPAuth()
  69         {
  70                 if (conn)
  71                         ldap_unbind_ext(conn, NULL, NULL);
  72         }
  73
  74         void OnRehash(User* user)
  75         {
  76                 ConfigReader Conf;
  77                 whitelistedcidrs.clear();
  78
  79                 base                    = Conf.ReadValue("ldapauth", "baserdn", 0);
  80                 attribute               = Conf.ReadValue("ldapauth", "attribute", 0);
  81                 ldapserver              = Conf.ReadValue("ldapauth", "server", 0);
  82                 allowpattern            = Conf.ReadValue("ldapauth", "allowpattern", 0);
  83                 killreason              = Conf.ReadValue("ldapauth", "killreason", 0);
  84                 std::string scope       = Conf.ReadValue("ldapauth", "searchscope", 0);
  85                 username                = Conf.ReadValue("ldapauth", "binddn", 0);
  86                 password                = Conf.ReadValue("ldapauth", "bindauth", 0);
  87                 verbose                 = Conf.ReadFlag("ldapauth", "verbose", 0);              /* Set to true if failed connects should be reported to operators */
  88                 useusername             = Conf.ReadFlag("ldapauth", "userfield", 0);
  89
  90                 ConfigTagList whitelisttags = ServerInstance->Config->ConfTags("ldapwhitelist");
  91
  92                 for (ConfigIter i = whitelisttags.first; i != whitelisttags.second; ++i)
  93                 {
  94                         std::string cidr = i->second->getString("cidr");
  95                         if (!cidr.empty()) {
  96                                 whitelistedcidrs.push_back(cidr);
  97                         }
  98                 }
  99
 100                 if (scope == "base")
 101                         searchscope = LDAP_SCOPE_BASE;
 102                 else if (scope == "onelevel")
 103                         searchscope = LDAP_SCOPE_ONELEVEL;
 104                 else searchscope = LDAP_SCOPE_SUBTREE;
 105
 106                 Connect();
 107         }
 108
 109         bool Connect()
 110         {
 111                 if (conn != NULL)
 112                         ldap_unbind_ext(conn, NULL, NULL);
 113                 int res, v = LDAP_VERSION3;
 114                 res = ldap_initialize(&conn, ldapserver.c_str());
 115                 if (res != LDAP_SUCCESS)
 116                 {
 117                         if (verbose)
 118                                 ServerInstance->SNO->WriteToSnoMask('c', "LDAP connection failed: %s", ldap_err2string(res));
 119                         conn = NULL;
 120                         return false;
 121                 }
 122
 123                 res = ldap_set_option(conn, LDAP_OPT_PROTOCOL_VERSION, (void *)&v);
 124                 if (res != LDAP_SUCCESS)
 125                 {
 126                         if (verbose)
 127                                 ServerInstance->SNO->WriteToSnoMask('c', "LDAP set protocol to v3 failed: %s", ldap_err2string(res));
 128                         ldap_unbind_ext(conn, NULL, NULL);
 129                         conn = NULL;
 130                         return false;
 131                 }
 132                 return true;
 133         }
 134
 135         ModResult OnUserRegister(LocalUser* user)
 136         {
 137                 if ((!allowpattern.empty()) && (InspIRCd::Match(user->nick,allowpattern)))
 138                 {
 139                         ldapAuthed.set(user,1);
 140                         return MOD_RES_PASSTHRU;
 141                 }
 142
 143                 for (std::vector<std::string>::iterator i = whitelistedcidrs.begin(); i != whitelistedcidrs.end(); i++)
 144                 {
 145                         if (InspIRCd::MatchCIDR(user->GetIPString(), *i, ascii_case_insensitive_map))
 146                         {
 147                                 ldapAuthed.set(user,1);
 148                                 return MOD_RES_PASSTHRU;
 149                         }
 150                 }
 151
 152                 if (!CheckCredentials(user))
 153                 {
 154                         ServerInstance->Users->QuitUser(user, killreason);
 155                         return MOD_RES_DENY;
 156                 }
 157                 return MOD_RES_PASSTHRU;
 158         }
 159
 160         bool CheckCredentials(LocalUser* user)
 161         {
 162                 if (conn == NULL)
 163                         if (!Connect())
 164                                 return false;
 165
 166                 if (user->password.empty())
 167                 {
 168                         if (verbose)
 169                                 ServerInstance->SNO->WriteToSnoMask('c', "Forbidden connection from %s!%s@%s (No password provided)", user->nick.c_str(), user->ident.c_str(), user->host.c_str());
 170                         return false;
 171                 }
 172
 173                 int res;
 174                 // bind anonymously if no bind DN and authentication are given in the config
 175                 struct berval cred;
 176                 cred.bv_val = const_cast<char*>(password.c_str());
 177                 cred.bv_len = password.length();
 178
 179                 if ((res = ldap_sasl_bind_s(conn, username.c_str(), LDAP_SASL_SIMPLE, &cred, NULL, NULL, NULL)) != LDAP_SUCCESS)
 180                 {
 181                         if (res == LDAP_SERVER_DOWN)
 182                         {
 183                                 // Attempt to reconnect if the connection dropped
 184                                 if (verbose)
 185                                         ServerInstance->SNO->WriteToSnoMask('a', "LDAP server has gone away - reconnecting...");
 186                                 Connect();
 187                                 res = ldap_sasl_bind_s(conn, username.c_str(), LDAP_SASL_SIMPLE, &cred, NULL, NULL, NULL);
 188                         }
 189
 190                         if (res != LDAP_SUCCESS)
 191                         {
 192                                 if (verbose)
 193                                         ServerInstance->SNO->WriteToSnoMask('c', "Forbidden connection from %s!%s@%s (LDAP bind failed: %s)", user->nick.c_str(), user->ident.c_str(), user->host.c_str(), ldap_err2string(res));
 194                                 ldap_unbind_ext(conn, NULL, NULL);
 195                                 conn = NULL;
 196                                 return false;
 197                         }
 198                 }
 199
 200                 LDAPMessage *msg, *entry;
 201                 std::string what = (attribute + "=" + (useusername ? user->ident : user->nick));
 202                 if ((res = ldap_search_ext_s(conn, base.c_str(), searchscope, what.c_str(), NULL, 0, NULL, NULL, NULL, 0, &msg)) != LDAP_SUCCESS)
 203                 {
 204                         // Do a second search, based on password, if it contains a :
 205                         // That is, PASS <user>:<password> will work.
 206                         size_t pos = user->password.find(":");
 207                         if (pos != std::string::npos)
 208                         {
 209                                 res = ldap_search_ext_s(conn, base.c_str(), searchscope, user->password.substr(0, pos).c_str(), NULL, 0, NULL, NULL, NULL, 0, &msg);
 210
 211                                 if (res)
 212                                 {
 213                                         // Trim the user: prefix, leaving just 'pass' for later password check
 214                                         user->password = user->password.substr(pos + 1);
 215                                 }
 216                         }
 217
 218                         // It may have found based on user:pass check above.
 219                         if (!res)
 220                         {
 221                                 if (verbose)
 222                                         ServerInstance->SNO->WriteToSnoMask('c', "Forbidden connection from %s!%s@%s (LDAP search failed: %s)", user->nick.c_str(), user->ident.c_str(), user->host.c_str(), ldap_err2string(res));
 223                                 return false;
 224                         }
 225                 }
 226                 if (ldap_count_entries(conn, msg) > 1)
 227                 {
 228                         if (verbose)
 229                                 ServerInstance->SNO->WriteToSnoMask('c', "Forbidden connection from %s!%s@%s (LDAP search returned more than one result: %s)", user->nick.c_str(), user->ident.c_str(), user->host.c_str(), ldap_err2string(res));
 230                         ldap_msgfree(msg);
 231                         return false;
 232                 }
 233                 if ((entry = ldap_first_entry(conn, msg)) == NULL)
 234                 {
 235                         if (verbose)
 236                                 ServerInstance->SNO->WriteToSnoMask('c', "Forbidden connection from %s!%s@%s (LDAP search returned no results: %s)", user->nick.c_str(), user->ident.c_str(), user->host.c_str(), ldap_err2string(res));
 237                         ldap_msgfree(msg);
 238                         return false;
 239                 }
 240                 cred.bv_val = (char*)user->password.data();
 241                 cred.bv_len = user->password.length();
 242                 if ((res = ldap_sasl_bind_s(conn, ldap_get_dn(conn, entry), LDAP_SASL_SIMPLE, &cred, NULL, NULL, NULL)) == LDAP_SUCCESS)
 243                 {
 244                         ldap_msgfree(msg);
 245                         ldapAuthed.set(user,1);
 246                         return true;
 247                 }
 248                 else
 249                 {
 250                         if (verbose)
 251                                 ServerInstance->SNO->WriteToSnoMask('c', "Forbidden connection from %s!%s@%s (%s)", user->nick.c_str(), user->ident.c_str(), user->host.c_str(), ldap_err2string(res));
 252                         ldap_msgfree(msg);
 253                         return false;
 254                 }
 255         }
 256
 257         ModResult OnCheckReady(LocalUser* user)
 258         {
 259                 return ldapAuthed.get(user) ? MOD_RES_PASSTHRU : MOD_RES_DENY;
 260         }
 261
 262         Version GetVersion()
 263         {
 264                 return Version("Allow/Deny connections based upon answer from LDAP server", VF_VENDOR);
 265         }
 266
 267 };
 268
 269 MODULE_INIT(ModuleLDAPAuth)