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         int searchscope;
  50         bool verbose;
  51         bool useusername;
  52         LDAP *conn;
  53
  54 public:
  55         ModuleLDAPAuth() : ldapAuthed("ldapauth", this)
  56         {
  57                 conn = NULL;
  58         }
  59
  60         void init()
  61         {
  62                 Implementation eventlist[] = { I_OnCheckReady, I_OnRehash, I_OnUserRegister };
  63                 ServerInstance->Modules->Attach(eventlist, this, 3);
  64                 OnRehash(NULL);
  65         }
  66
  67         ~ModuleLDAPAuth()
  68         {
  69                 if (conn)
  70                         ldap_unbind_ext(conn, NULL, NULL);
  71         }
  72
  73         void OnRehash(User* user)
  74         {
  75                 ConfigReader Conf;
  76
  77                 base                    = Conf.ReadValue("ldapauth", "baserdn", 0);
  78                 attribute               = Conf.ReadValue("ldapauth", "attribute", 0);
  79                 ldapserver              = Conf.ReadValue("ldapauth", "server", 0);
  80                 allowpattern            = Conf.ReadValue("ldapauth", "allowpattern", 0);
  81                 killreason              = Conf.ReadValue("ldapauth", "killreason", 0);
  82                 std::string scope       = Conf.ReadValue("ldapauth", "searchscope", 0);
  83                 username                = Conf.ReadValue("ldapauth", "binddn", 0);
  84                 password                = Conf.ReadValue("ldapauth", "bindauth", 0);
  85                 verbose                 = Conf.ReadFlag("ldapauth", "verbose", 0);              /* Set to true if failed connects should be reported to operators */
  86                 useusername             = Conf.ReadFlag("ldapauth", "userfield", 0);
  87
  88                 if (scope == "base")
  89                         searchscope = LDAP_SCOPE_BASE;
  90                 else if (scope == "onelevel")
  91                         searchscope = LDAP_SCOPE_ONELEVEL;
  92                 else searchscope = LDAP_SCOPE_SUBTREE;
  93
  94                 Connect();
  95         }
  96
  97         bool Connect()
  98         {
  99                 if (conn != NULL)
 100                         ldap_unbind_ext(conn, NULL, NULL);
 101                 int res, v = LDAP_VERSION3;
 102                 res = ldap_initialize(&conn, ldapserver.c_str());
 103                 if (res != LDAP_SUCCESS)
 104                 {
 105                         if (verbose)
 106                                 ServerInstance->SNO->WriteToSnoMask('c', "LDAP connection failed: %s", ldap_err2string(res));
 107                         conn = NULL;
 108                         return false;
 109                 }
 110
 111                 res = ldap_set_option(conn, LDAP_OPT_PROTOCOL_VERSION, (void *)&v);
 112                 if (res != LDAP_SUCCESS)
 113                 {
 114                         if (verbose)
 115                                 ServerInstance->SNO->WriteToSnoMask('c', "LDAP set protocol to v3 failed: %s", ldap_err2string(res));
 116                         ldap_unbind_ext(conn, NULL, NULL);
 117                         conn = NULL;
 118                         return false;
 119                 }
 120                 return true;
 121         }
 122
 123         ModResult OnUserRegister(LocalUser* user)
 124         {
 125                 if ((!allowpattern.empty()) && (InspIRCd::Match(user->nick,allowpattern)))
 126                 {
 127                         ldapAuthed.set(user,1);
 128                         return MOD_RES_PASSTHRU;
 129                 }
 130
 131                 if (!CheckCredentials(user))
 132                 {
 133                         ServerInstance->Users->QuitUser(user, killreason);
 134                         return MOD_RES_DENY;
 135                 }
 136                 return MOD_RES_PASSTHRU;
 137         }
 138
 139         bool CheckCredentials(LocalUser* user)
 140         {
 141                 if (conn == NULL)
 142                         if (!Connect())
 143                                 return false;
 144
 145                 if (user->password.empty())
 146                 {
 147                         if (verbose)
 148                                 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());
 149                         return false;
 150                 }
 151
 152                 int res;
 153                 // bind anonymously if no bind DN and authentication are given in the config
 154                 struct berval cred;
 155                 cred.bv_val = const_cast<char*>(password.c_str());
 156                 cred.bv_len = password.length();
 157
 158                 if ((res = ldap_sasl_bind_s(conn, username.c_str(), LDAP_SASL_SIMPLE, &cred, NULL, NULL, NULL)) != LDAP_SUCCESS)
 159                 {
 160                         if (res == LDAP_SERVER_DOWN)
 161                         {
 162                                 // Attempt to reconnect if the connection dropped
 163                                 if (verbose)
 164                                         ServerInstance->SNO->WriteToSnoMask('a', "LDAP server has gone away - reconnecting...");
 165                                 Connect();
 166                                 res = ldap_sasl_bind_s(conn, username.c_str(), LDAP_SASL_SIMPLE, &cred, NULL, NULL, NULL);
 167                         }
 168
 169                         if (res != LDAP_SUCCESS)
 170                         {
 171                                 if (verbose)
 172                                         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));
 173                                 ldap_unbind_ext(conn, NULL, NULL);
 174                                 conn = NULL;
 175                                 return false;
 176                         }
 177                 }
 178
 179                 LDAPMessage *msg, *entry;
 180                 std::string what = (attribute + "=" + (useusername ? user->ident : user->nick));
 181                 if ((res = ldap_search_ext_s(conn, base.c_str(), searchscope, what.c_str(), NULL, 0, NULL, NULL, NULL, 0, &msg)) != LDAP_SUCCESS)
 182                 {
 183                         // Do a second search, based on password, if it contains a :
 184                         // That is, PASS <user>:<password> will work.
 185                         size_t pos = user->password.find(":");
 186                         if (pos != std::string::npos)
 187                         {
 188                                 res = ldap_search_ext_s(conn, base.c_str(), searchscope, user->password.substr(0, pos).c_str(), NULL, 0, NULL, NULL, NULL, 0, &msg);
 189
 190                                 if (res)
 191                                 {
 192                                         // Trim the user: prefix, leaving just 'pass' for later password check
 193                                         user->password = user->password.substr(pos + 1);
 194                                 }
 195                         }
 196
 197                         // It may have found based on user:pass check above.
 198                         if (!res)
 199                         {
 200                                 if (verbose)
 201                                         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));
 202                                 return false;
 203                         }
 204                 }
 205                 if (ldap_count_entries(conn, msg) > 1)
 206                 {
 207                         if (verbose)
 208                                 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));
 209                         ldap_msgfree(msg);
 210                         return false;
 211                 }
 212                 if ((entry = ldap_first_entry(conn, msg)) == NULL)
 213                 {
 214                         if (verbose)
 215                                 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));
 216                         ldap_msgfree(msg);
 217                         return false;
 218                 }
 219                 cred.bv_val = (char*)user->password.data();
 220                 cred.bv_len = user->password.length();
 221                 if ((res = ldap_sasl_bind_s(conn, ldap_get_dn(conn, entry), LDAP_SASL_SIMPLE, &cred, NULL, NULL, NULL)) == LDAP_SUCCESS)
 222                 {
 223                         ldap_msgfree(msg);
 224                         ldapAuthed.set(user,1);
 225                         return true;
 226                 }
 227                 else
 228                 {
 229                         if (verbose)
 230                                 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));
 231                         ldap_msgfree(msg);
 232                         return false;
 233                 }
 234         }
 235
 236         ModResult OnCheckReady(LocalUser* user)
 237         {
 238                 return ldapAuthed.get(user) ? MOD_RES_PASSTHRU : MOD_RES_DENY;
 239         }
 240
 241         Version GetVersion()
 242         {
 243                 return Version("Allow/Deny connections based upon answer from LDAP server", VF_VENDOR);
 244         }
 245
 246 };
 247
 248 MODULE_INIT(ModuleLDAPAuth)