/*
* InspIRCd -- Internet Relay Chat Daemon
*
* Copyright (C) 2011 Pierre Carrier <pierre@spotify.com>
* Copyright (C) 2009-2010 Robin Burchell <robin+git@viroteck.net>
* Copyright (C) 2009 Daniel De Graaf <danieldg@inspircd.org>
* Copyright (C) 2008 Pippijn van Steenhoven <pip88nl@gmail.com>
* Copyright (C) 2008 Craig Edwards <craigedwards@brainbox.cc>
* Copyright (C) 2008 Dennis Friis <peavey@inspircd.org>
* Copyright (C) 2007 Carsten Valdemar Munk <carsten.munk+inspircd@gmail.com>
*
* This file is part of InspIRCd. InspIRCd is free software: you can
* redistribute it and/or modify it under the terms of the GNU General Public
* License as published by the Free Software Foundation, version 2.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
* FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
* details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "inspircd.h"
#include "users.h"
#include "channels.h"
#include "modules.h"
#include <ldap.h>
#ifdef _WIN32
# pragma comment(lib, "libldap.lib")
# pragma comment(lib, "liblber.lib")
#endif
/* $ModDesc: Allow/Deny connections based upon answer from LDAP server */
/* $LinkerFlags: -lldap */
struct RAIILDAPString
{
char *str;
RAIILDAPString(char *Str)
: str(Str)
{
}
~RAIILDAPString()
{
ldap_memfree(str);
}
operator char*()
{
return str;
}
operator std::string()
{
return str;
}
};
struct RAIILDAPMessage
{
RAIILDAPMessage()
{
}
~RAIILDAPMessage()
{
dealloc();
}
void dealloc()
{
ldap_msgfree(msg);
}
operator LDAPMessage*()
{
return msg;
}
LDAPMessage **operator &()
{
return &msg;
}
LDAPMessage *msg;
};
class ModuleLDAPAuth : public Module
{
LocalIntExt ldapAuthed;
LocalStringExt ldapVhost;
std::string base;
std::string attribute;
std::string ldapserver;
std::string allowpattern;
std::string killreason;
std::string username;
std::string password;
std::string vhost;
std::vector<std::string> whitelistedcidrs;
std::vector<std::pair<std::string, std::string> > requiredattributes;
int searchscope;
bool verbose;
bool useusername;
LDAP *conn;
public:
ModuleLDAPAuth()
: ldapAuthed("ldapauth", this)
, ldapVhost("ldapauth_vhost", this)
{
conn = NULL;
}
void init()
{
ServerInstance->Modules->AddService(ldapAuthed);
ServerInstance->Modules->AddService(ldapVhost);
Implementation eventlist[] = { I_OnCheckReady, I_OnRehash,I_OnUserRegister, I_OnUserConnect };
ServerInstance->Modules->Attach(eventlist, this, sizeof(eventlist)/sizeof(Implementation));
OnRehash(NULL);
}
~ModuleLDAPAuth()
{
if (conn)
ldap_unbind_ext(conn, NULL, NULL);
}
void OnRehash(User* user)
{
ConfigTag* tag = ServerInstance->Config->ConfValue("ldapauth");
whitelistedcidrs.clear();
requiredattributes.clear();
base = tag->getString("baserdn");
attribute = tag->getString("attribute");
ldapserver = tag->getString("server");
allowpattern = tag->getString("allowpattern");
killreason = tag->getString("killreason");
std::string scope = tag->getString("searchscope");
username = tag->getString("binddn");
password = tag->getString("bindauth");
vhost = tag->getString("host");
verbose = tag->getBool("verbose"); /* Set to true if failed connects should be reported to operators */
useusername = tag->getBool("userfield");
ConfigTagList whitelisttags = ServerInstance->Config->ConfTags("ldapwhitelist");
for (ConfigIter i = whitelisttags.first; i != whitelisttags.second; ++i)
{
std::string cidr = i->second->getString("cidr");
if (!cidr.empty()) {
whitelistedcidrs.push_back(cidr);
}
}
ConfigTagList attributetags = ServerInstance->Config->ConfTags("ldaprequire");
for (ConfigIter i = attributetags.first; i != attributetags.second; ++i)
{
const std::string attr = i->second->getString("attribute");
const std::string val = i->second->getString("value");
if (!attr.empty() && !val.empty())
requiredattributes.push_back(make_pair(attr, val));
}
if (scope == "base")
searchscope = LDAP_SCOPE_BASE;
else if (scope == "onelevel")
searchscope = LDAP_SCOPE_ONELEVEL;
else searchscope = LDAP_SCOPE_SUBTREE;
Connect();
}
bool Connect()
{
if (conn != NULL)
ldap_unbind_ext(conn, NULL, NULL);
int res, v = LDAP_VERSION3;
res = ldap_initialize(&conn, ldapserver.c_str());
if (res != LDAP_SUCCESS)
{
if (verbose)
ServerInstance->SNO->WriteToSnoMask('c', "LDAP connection failed: %s", ldap_err2string(res));
conn = NULL;
return false;
}
res = ldap_set_option(conn, LDAP_OPT_PROTOCOL_VERSION, (void *)&v);
if (res != LDAP_SUCCESS)
{
if (verbose)
ServerInstance->SNO->WriteToSnoMask('c', "LDAP set protocol to v3 failed: %s", ldap_err2string(res));
ldap_unbind_ext(conn, NULL, NULL);
conn = NULL;
return false;
}
return true;
}
std::string SafeReplace(const std::string &text, std::map<std::string,
std::string> &replacements)
{
std::string result;
result.reserve(MAXBUF);
for (unsigned int i = 0; i < text.length(); ++i) {
char c = text[i];
if (c == '$') {
// find the first nonalpha
i++;
unsigned int start = i;
while (i < text.length() - 1 && isalpha(text[i + 1]))
++i;
std::string key = text.substr(start, (i - start) + 1);
result.append(replacements[key]);
} else {
result.push_back(c);
}
}
return result;
}
virtual void OnUserConnect(LocalUser *user)
{
std::string* cc = ldapVhost.get(user);
if (cc)
{
user->ChangeDisplayedHost(cc->c_str());
ldapVhost.unset(user);
}
}
ModResult OnUserRegister(LocalUser* user)
{
if ((!allowpattern.empty()) && (InspIRCd::Match(user->nick,allowpattern)))
{
ldapAuthed.set(user,1);
return MOD_RES_PASSTHRU;
}
for (std::vector<std::string>::iterator i = whitelistedcidrs.begin(); i != whitelistedcidrs.end(); i++)
{
if (InspIRCd::MatchCIDR(user->GetIPString(), *i, ascii_case_insensitive_map))
{
ldapAuthed.set(user,1);
return MOD_RES_PASSTHRU;
}
}
if (!CheckCredentials(user))
{
ServerInstance->Users->QuitUser(user, killreason);
return MOD_RES_DENY;
}
return MOD_RES_PASSTHRU;
}
bool CheckCredentials(LocalUser* user)
{
if (conn == NULL)
if (!Connect())
return false;
if (user->password.empty())
{
if (verbose)
ServerInstance->SNO->WriteToSnoMask('c', "Forbidden connection from %s (No password provided)", user->GetFullRealHost().c_str());
return false;
}
int res;
// bind anonymously if no bind DN and authentication are given in the config
struct berval cred;
cred.bv_val = const_cast<char*>(password.c_str());
cred.bv_len = password.length();
if ((res = ldap_sasl_bind_s(conn, username.c_str(), LDAP_SASL_SIMPLE, &cred, NULL, NULL, NULL)) != LDAP_SUCCESS)
{
if (res == LDAP_SERVER_DOWN)
{
// Attempt to reconnect if the connection dropped
if (verbose)
ServerInstance->SNO->WriteToSnoMask('a', "LDAP server has gone away - reconnecting...");
Connect();
res = ldap_sasl_bind_s(conn, username.c_str(), LDAP_SASL_SIMPLE, &cred, NULL, NULL, NULL);
}
if (res != LDAP_SUCCESS)
{
if (verbose)
ServerInstance->SNO->WriteToSnoMask('c', "Forbidden connection from %s (LDAP bind failed: %s)", user->GetFullRealHost().c_str(), ldap_err2string(res));
ldap_unbind_ext(conn, NULL, NULL);
conn = NULL;
return false;
}
}
RAIILDAPMessage msg;
std::string what = (attribute + "=" + (useusername ? user->ident : user->nick));
if ((res = ldap_search_ext_s(conn, base.c_str(), searchscope, what.c_str(), NULL, 0, NULL, NULL, NULL, 0, &msg)) != LDAP_SUCCESS)
{
// Do a second search, based on password, if it contains a :
// That is, PASS <user>:<password> will work.
size_t pos = user->password.find(":");
if (pos != std::string::npos)
{
// manpage says we must deallocate regardless of success or failure
// since we're about to do another query (and reset msg), first
// free the old one.
msg.dealloc();
std::string cutpassword = user->password.substr(0, pos);
res = ldap_search_ext_s(conn, base.c_str(), searchscope, cutpassword.c_str(), NULL, 0, NULL, NULL, NULL, 0, &msg);
if (res == LDAP_SUCCESS)
{
// Trim the user: prefix, leaving just 'pass' for later password check
user->password = user->password.substr(pos + 1);
}
}
// It may have found based on user:pass check above.
if (res != LDAP_SUCCESS)
{
if (verbose)
ServerInstance->SNO->WriteToSnoMask('c', "Forbidden connection from %s (LDAP search failed: %s)", user->GetFullRealHost().c_str(), ldap_err2string(res));
return false;
}
}
if (ldap_count_entries(conn, msg) > 1)
{
if (verbose)
ServerInstance->SNO->WriteToSnoMask('c', "Forbidden connection from %s (LDAP search returned more than one result: %s)", user->GetFullRealHost().c_str(), ldap_err2string(res));
return false;
}
LDAPMessage *entry;
if ((entry = ldap_first_entry(conn, msg)) == NULL)
{
if (verbose)
ServerInstance->SNO->WriteToSnoMask('c', "Forbidden connection from %s (LDAP search returned no results: %s)", user->GetFullRealHost().c_str(), ldap_err2string(res));
return false;
}
cred.bv_val = (char*)user->password.data();
cred.bv_len = user->password.length();
RAIILDAPString DN(ldap_get_dn(conn, entry));
if ((res = ldap_sasl_bind_s(conn, DN, LDAP_SASL_SIMPLE, &cred, NULL, NULL, NULL)) != LDAP_SUCCESS)
{
if (verbose)
ServerInstance->SNO->WriteToSnoMask('c', "Forbidden connection from %s (%s)", user->GetFullRealHost().c_str(), ldap_err2string(res));
return false;
}
if (!requiredattributes.empty())
{
bool authed = false;
for (std::vector<std::pair<std::string, std::string> >::const_iterator it = requiredattributes.begin(); it != requiredattributes.end(); ++it)
{
const std::string &attr = it->first;
const std::string &val = it->second;
struct berval attr_value;
attr_value.bv_val = const_cast<char*>(val.c_str());
attr_value.bv_len = val.length();
ServerInstance->Logs->Log("m_ldapauth", DEBUG, "LDAP compare: %s=%s", attr.c_str(), val.c_str());
authed = (ldap_compare_ext_s(conn, DN, attr.c_str(), &attr_value, NULL, NULL) == LDAP_COMPARE_TRUE);
if (authed)
break;
}
if (!authed)
{
if (verbose)
ServerInstance->SNO->WriteToSnoMask('c', "Forbidden connection from %s (Lacks required LDAP attributes)", user->GetFullRealHost().c_str());
return false;
}
}
if (!vhost.empty())
{
irc::commasepstream stream(DN);
// mashed map of key:value parts of the DN
std::map<std::string, std::string> dnParts;
std::string dnPart;
while (stream.GetToken(dnPart))
{
std::string::size_type pos = dnPart.find('=');
if (pos == std::string::npos) // malformed
continue;
std::string key = dnPart.substr(0, pos);
std::string value = dnPart.substr(pos + 1, dnPart.length() - pos + 1); // +1s to skip the = itself
dnParts[key] = value;
}
// change host according to config key
ldapVhost.set(user, SafeReplace(vhost, dnParts));
}
ldapAuthed.set(user,1);
return true;
}
ModResult OnCheckReady(LocalUser* user)
{
return ldapAuthed.get(user) ? MOD_RES_PASSTHRU : MOD_RES_DENY;
}
Version GetVersion()
{
return Version("Allow/Deny connections based upon answer from LDAP server", VF_VENDOR);
}
};
MODULE_INIT(ModuleLDAPAuth)
