/* +------------------------------------+
* | Inspire Internet Relay Chat Daemon |
* +------------------------------------+
*
* InspIRCd: (C) 2002-2009 InspIRCd Development Team
* See: http://wiki.inspircd.org/Credits
*
* This program is free but copyrighted software; see
* the file COPYING for details.
*
* ---------------------------------------------------
*/
#include "inspircd.h"
#include "m_hash.h"
/* $ModDesc: Provides masking of user hostnames */
/* $ModDep: m_hash.h */
/** Handles user mode +x
*/
class CloakUser : public ModeHandler
{
public:
std::string prefix;
unsigned int key1;
unsigned int key2;
unsigned int key3;
unsigned int key4;
bool ipalways;
Module* Sender;
Module* HashProvider;
const char *xtab[4];
std::string debounce_uid;
time_t debounce_ts;
int debounce_count;
/** This function takes a domain name string and returns just the last two domain parts,
* or the last domain part if only two are available. Failing that it just returns what it was given.
*
* For example, if it is passed "svn.inspircd.org" it will return ".inspircd.org".
* If it is passed "brainbox.winbot.co.uk" it will return ".co.uk",
* and if it is passed "localhost.localdomain" it will return ".localdomain".
*
* This is used to ensure a significant part of the host is always cloaked (see Bug #216)
*/
std::string LastTwoDomainParts(const std::string &host)
{
int dots = 0;
std::string::size_type splitdot = host.length();
for (std::string::size_type x = host.length() - 1; x; --x)
{
if (host[x] == '.')
{
splitdot = x;
dots++;
}
if (dots >= 3)
break;
}
if (splitdot == host.length())
return "";
else
return host.substr(splitdot);
}
CloakUser(InspIRCd* Instance, Module* source, Module* Hash) : ModeHandler(Instance, 'x', 0, 0, false, MODETYPE_USER, false), Sender(source), HashProvider(Hash)
{
}
ModeAction OnModeChange(User* source, User* dest, Channel* channel, std::string ¶meter, bool adding, bool)
{
/* For remote clients, we dont take any action, we just allow it.
* The local server where they are will set their cloak instead.
* This is fine, as we will recieve it later.
*/
if (!IS_LOCAL(dest))
{
dest->SetMode('x',adding);
return MODEACTION_ALLOW;
}
if (dest->uuid == debounce_uid && debounce_ts == ServerInstance->Time())
{
// prevent spamming using /mode user +x-x+x-x+x-x
if (++debounce_count > 2)
return MODEACTION_DENY;
}
else
{
debounce_uid = dest->uuid;
debounce_count = 1;
debounce_ts = ServerInstance->Time();
}
/* don't allow this user to spam modechanges */
if (source == dest)
dest->IncreasePenalty(5);
if (adding)
{
if(!dest->IsModeSet('x'))
{
/* The mode is being turned on - so attempt to
* allocate the user a cloaked host using a non-reversible
* algorithm (its simple, but its non-reversible so the
* simplicity doesnt really matter). This algorithm
* will not work if the user has only one level of domain
* naming in their hostname (e.g. if they are on a lan or
* are connecting via localhost) -- this doesnt matter much.
*/
std::string* cloak;
if (!dest->GetExt("cloaked_host", cloak))
{
/* Force creation of missing cloak */
Sender->OnUserConnect(dest);
}
if (dest->GetExt("cloaked_host", cloak))
{
dest->ChangeDisplayedHost(cloak->c_str());
dest->SetMode('x',true);
return MODEACTION_ALLOW;
}
}
}
else
{
if (dest->IsModeSet('x'))
{
/* User is removing the mode, so just restore their real host
* and make it match the displayed one.
*/
dest->ChangeDisplayedHost(dest->host.c_str());
dest->SetMode('x',false);
return MODEACTION_ALLOW;
}
}
return MODEACTION_DENY;
}
std::string Cloak4(const char* ip)
{
unsigned int iv[] = { key1, key2, key3, key4 };
irc::sepstream seps(ip, '.');
std::string ra[4];;
std::string octet[4];
int i[4];
for (int j = 0; j < 4; j++)
{
seps.GetToken(octet[j]);
i[j] = atoi(octet[j].c_str());
}
octet[3] = octet[0] + "." + octet[1] + "." + octet[2] + "." + octet[3];
octet[2] = octet[0] + "." + octet[1] + "." + octet[2];
octet[1] = octet[0] + "." + octet[1];
/* Reset the Hash module and send it our IV */
HashResetRequest(Sender, HashProvider).Send();
HashKeyRequest(Sender, HashProvider, iv).Send();
/* Send the Hash module a different hex table for each octet group's Hash sum */
for (int k = 0; k < 4; k++)
{
HashHexRequest(Sender, HashProvider, xtab[(iv[k]+i[k]) % 4]).Send();
ra[k] = std::string(HashSumRequest(Sender, HashProvider, octet[k]).Send()).substr(0,6);
}
/* Stick them all together */
return std::string().append(ra[0]).append(".").append(ra[1]).append(".").append(ra[2]).append(".").append(ra[3]);
}
std::string Cloak6(const char* ip)
{
unsigned int iv[] = { key1, key2, key3, key4 };
std::vector<std::string> hashies;
std::string item;
int rounds = 0;
/* Reset the Hash module and send it our IV */
HashResetRequest(Sender, HashProvider).Send();
HashKeyRequest(Sender, HashProvider, iv).Send();
for (const char* input = ip; *input; input++)
{
item += *input;
if (item.length() > 7)
{
/* Send the Hash module a different hex table for each octet group's Hash sum */
HashHexRequest(Sender, HashProvider, xtab[(key1+rounds) % 4]).Send();
hashies.push_back(std::string(HashSumRequest(Sender, HashProvider, item).Send()).substr(0,8));
item.clear();
}
rounds++;
}
if (!item.empty())
{
/* Send the Hash module a different hex table for each octet group's Hash sum */
HashHexRequest(Sender, HashProvider, xtab[(key1+rounds) % 4]).Send();
hashies.push_back(std::string(HashSumRequest(Sender, HashProvider, item).Send()).substr(0,8));
item.clear();
}
/* Stick them all together */
return irc::stringjoiner(":", hashies, 0, hashies.size() - 1).GetJoined();
}
void DoRehash()
{
ConfigReader Conf(ServerInstance);
bool lowercase;
/* These are *not* using the need_positive parameter of ReadInteger -
* that will limit the valid values to only the positive values in a
* signed int. Instead, accept any value that fits into an int and
* cast it to an unsigned int. That will, a bit oddly, give us the full
* spectrum of an unsigned integer. - Special */
key1 = key2 = key3 = key4 = 0;
key1 = (unsigned int) Conf.ReadInteger("cloak","key1",0,false);
key2 = (unsigned int) Conf.ReadInteger("cloak","key2",0,false);
key3 = (unsigned int) Conf.ReadInteger("cloak","key3",0,false);
key4 = (unsigned int) Conf.ReadInteger("cloak","key4",0,false);
prefix = Conf.ReadValue("cloak","prefix",0);
ipalways = Conf.ReadFlag("cloak", "ipalways", 0);
lowercase = Conf.ReadFlag("cloak", "lowercase", 0);
if (!lowercase)
{
xtab[0] = "F92E45D871BCA630";
xtab[1] = "A1B9D80C72E653F4";
xtab[2] = "1ABC078934DEF562";
xtab[3] = "ABCDEF5678901234";
}
else
{
xtab[0] = "f92e45d871bca630";
xtab[1] = "a1b9d80c72e653f4";
xtab[2] = "1abc078934def562";
xtab[3] = "abcdef5678901234";
}
if (prefix.empty())
prefix = ServerInstance->Config->Network;
if (!key1 || !key2 || !key3 || !key4)
{
std::string detail;
if (!key1)
detail = "<cloak:key1> is not valid, it may be set to a too high/low value, or it may not exist.";
else if (!key2)
detail = "<cloak:key2> is not valid, it may be set to a too high/low value, or it may not exist.";
else if (!key3)
detail = "<cloak:key3> is not valid, it may be set to a too high/low value, or it may not exist.";
else if (!key4)
detail = "<cloak:key4> is not valid, it may be set to a too high/low value, or it may not exist.";
throw ModuleException("You have not defined cloak keys for m_cloaking!!! THIS IS INSECURE AND SHOULD BE CHECKED! - " + detail);
}
}
};
class ModuleCloaking : public Module
{
private:
CloakUser* cu;
Module* HashModule;
public:
ModuleCloaking(InspIRCd* Me)
: Module(Me)
{
/* Attempt to locate the md5 service provider, bail if we can't find it */
HashModule = ServerInstance->Modules->Find("m_md5.so");
if (!HashModule)
throw ModuleException("Can't find m_md5.so. Please load m_md5.so before m_cloaking.so.");
cu = new CloakUser(ServerInstance, this, HashModule);
try
{
OnRehash(NULL);
}
catch (ModuleException &e)
{
delete cu;
throw e;
}
/* Register it with the core */
if (!ServerInstance->Modes->AddMode(cu))
{
delete cu;
throw ModuleException("Could not add new modes!");
}
ServerInstance->Modules->UseInterface("HashRequest");
Implementation eventlist[] = { I_OnRehash, I_OnUserDisconnect, I_OnCleanup, I_OnCheckBan, I_OnUserConnect, I_OnSyncUserMetaData, I_OnCleanup };
ServerInstance->Modules->Attach(eventlist, this, 6);
CloakExistingUsers();
}
void OnSyncUserMetaData(User* user, Module* proto,void* opaque, const std::string &extname, bool displayable)
{
if ((displayable) && (extname == "cloaked_host"))
{
std::string* cloak;
if (user->GetExt("cloaked_host", cloak))
proto->ProtoSendMetaData(opaque, TYPE_USER, user, extname, *cloak);
}
}
void CloakExistingUsers()
{
std::string* cloak;
for (std::vector<User*>::iterator u = ServerInstance->Users->local_users.begin(); u != ServerInstance->Users->local_users.end(); u++)
{
if (!(*u)->GetExt("cloaked_host", cloak))
{
OnUserConnect(*u);
}
}
}
virtual int OnCheckBan(User* user, Channel* chan)
{
char mask[MAXBUF];
std::string* tofree;
/* Check if they have a cloaked host, but are not using it */
if (user->GetExt("cloaked_host", tofree) && *tofree != user->dhost)
{
snprintf(mask, MAXBUF, "%s!%s@%s", user->nick.c_str(), user->ident.c_str(), tofree->c_str());
for (BanList::iterator i = chan->bans.begin(); i != chan->bans.end(); i++)
{
if (InspIRCd::Match(mask,i->data))
return -1;
}
}
return 0;
}
void Prioritize()
{
/* Needs to be after m_banexception etc. */
ServerInstance->Modules->SetPriority(this, I_OnCheckBan, PRIORITY_LAST);
/* but before m_conn_umodes, so host is generated ready to apply */
Module *um = ServerInstance->Modules->Find("m_conn_umodes.so");
ServerInstance->Modules->SetPriority(this, I_OnUserConnect, PRIORITY_AFTER, &um);
}
virtual void OnUserDisconnect(User* user)
{
std::string* tofree;
if (user->GetExt("cloaked_host", tofree))
{
delete tofree;
user->Shrink("cloaked_host");
}
}
virtual void OnCleanup(int target_type, void* item)
{
if (target_type == TYPE_USER)
OnUserDisconnect((User*)item);
}
virtual ~ModuleCloaking()
{
ServerInstance->Modes->DelMode(cu);
delete cu;
ServerInstance->Modules->DoneWithInterface("HashRequest");
}
virtual Version GetVersion()
{
// returns the version number of the module to be
// listed in /MODULES
return Version("$Id$", VF_COMMON|VF_VENDOR,API_VERSION);
}
virtual void OnRehash(User* user)
{
cu->DoRehash();
}
virtual void OnUserConnect(User* dest)
{
std::string* tofree;
if (dest->GetExt("cloaked_host", tofree))
return;
if (dest->host.find('.') != std::string::npos || dest->host.find(':') != std::string::npos)
{
unsigned int iv[] = { cu->key1, cu->key2, cu->key3, cu->key4 };
std::string a = cu->LastTwoDomainParts(dest->host);
std::string b;
/* InspIRCd users have two hostnames; A displayed
* hostname which can be modified by modules (e.g.
* to create vhosts, implement chghost, etc) and a
* 'real' hostname which you shouldnt write to.
*/
/* 2008/08/18: add <cloak:ipalways> which always cloaks
* the IP, for anonymity. --nenolod
*/
if (!cu->ipalways)
{
/** Reset the Hash module, and send it our IV
* We use the default hex table here (for no reason whatsoever)
*/
HashResetRequest(this, cu->HashProvider).Send();
HashKeyRequest(this, cu->HashProvider, iv).Send();
/* Generate a cloak using specialized Hash */
std::string hostcloak = cu->prefix + "-" + std::string(HashSumRequest(this, cu->HashProvider, dest->host.c_str()).Send()).substr(0,8) + a;
/* Fix by brain - if the cloaked host is > the max length of a host (64 bytes
* according to the DNS RFC) then tough titty, they get cloaked as an IP.
* Their ISP shouldnt go to town on subdomains, or they shouldnt have a kiddie
* vhost.
*/
#ifdef IPV6
in6_addr testaddr;
in_addr testaddr2;
if ((dest->GetProtocolFamily() == AF_INET6) && (inet_pton(AF_INET6,dest->host.c_str(),&testaddr) < 1) && (hostcloak.length() <= 64))
/* Invalid ipv6 address, and ipv6 user (resolved host) */
b = hostcloak;
else if ((dest->GetProtocolFamily() == AF_INET) && (inet_aton(dest->host.c_str(),&testaddr2) < 1) && (hostcloak.length() <= 64))
/* Invalid ipv4 address, and ipv4 user (resolved host) */
b = hostcloak;
else
/* Valid ipv6 or ipv4 address (not resolved) ipv4 or ipv6 user */
b = ((!strchr(dest->host.c_str(),':')) ? cu->Cloak4(dest->host.c_str()) : cu->Cloak6(dest->host.c_str()));
#else
in_addr testaddr;
if ((inet_aton(dest->host.c_str(),&testaddr) < 1) && (hostcloak.length() <= 64))
/* Invalid ipv4 address, and ipv4 user (resolved host) */
b = hostcloak;
else
/* Valid ipv4 address (not resolved) ipv4 user */
b = cu->Cloak4(dest->host.c_str());
#endif
}
else
{
#ifdef IPV6
if (dest->GetProtocolFamily() == AF_INET6)
b = cu->Cloak6(dest->GetIPString());
#endif
if (dest->GetProtocolFamily() == AF_INET)
b = cu->Cloak4(dest->GetIPString());
}
dest->Extend("cloaked_host", new std::string(b));
}
}
};
MODULE_INIT(ModuleCloaking)
