/* +------------------------------------+
* | Inspire Internet Relay Chat Daemon |
* +------------------------------------+
*
* InspIRCd: (C) 2002-2011 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 "hash.h"
/* $ModDesc: Provides masking of user hostnames */
namespace cloak_12
{
enum CloakMode
{
/** 1.2-compatible host-based cloak */
MODE_COMPAT_HOST,
/** 1.2-compatible IP-only cloak */
MODE_COMPAT_IPONLY
};
/** Handles user mode +x
*/
class CloakUser : public ModeHandler
{
public:
LocalStringExt ext;
std::string debounce_uid;
time_t debounce_ts;
int debounce_count;
CloakUser(Module* source)
: ModeHandler(source, "cloak_12", 'x', PARAM_NONE, MODETYPE_USER),
ext(EXTENSIBLE_USER, "cloaked_host", source), debounce_ts(0), debounce_count(0)
{
}
ModeAction OnModeChange(User* source, User* dest, Channel* channel, std::string ¶meter, bool adding)
{
LocalUser* user = IS_LOCAL(dest);
/* For remote clients, we don't take any action, we just allow it.
* The local server where they are will set their cloak instead.
* This is fine, as we will receive it later.
*/
if (!user)
{
dest->SetMode('x',adding);
return MODEACTION_ALLOW;
}
if (user->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 = user->uuid;
debounce_count = 1;
debounce_ts = ServerInstance->Time();
}
if (adding == user->IsModeSet('x'))
return MODEACTION_DENY;
/* don't allow this user to spam modechanges */
if (source == dest)
user->CommandFloodPenalty += 5000;
if (adding)
{
std::string* cloak = ext.get(user);
if (!cloak)
{
/* Force creation of missing cloak */
creator->OnUserConnect(user);
cloak = ext.get(user);
}
if (cloak)
{
user->ChangeDisplayedHost(cloak->c_str());
user->SetMode('x',true);
return MODEACTION_ALLOW;
}
else
return MODEACTION_DENY;
}
else
{
/* User is removing the mode, so restore their real host
* and make it match the displayed one.
*/
user->SetMode('x',false);
user->ChangeDisplayedHost(user->host.c_str());
return MODEACTION_ALLOW;
}
}
};
class CommandCloak : public Command
{
public:
CommandCloak(Module* Creator) : Command(Creator, "CLOAK", 1)
{
flags_needed = 'o';
syntax = "<host>";
}
CmdResult Handle(const std::vector<std::string> ¶meters, User *user);
};
class ModuleCloaking : public Module
{
public:
CloakUser cu;
CloakMode mode;
CommandCloak ck;
std::string prefix;
unsigned int compatkey[4];
const char* xtab[4];
dynamic_reference<HashProvider> Hash;
ModuleCloaking() : cu(this), mode(MODE_COMPAT_HOST), ck(this), Hash("hash/md5")
{
}
void init()
{
ServerInstance->Modules->AddService(cu);
ServerInstance->Modules->AddService(ck);
ServerInstance->Modules->AddService(cu.ext);
Implementation eventlist[] = { I_OnCheckBan, I_OnUserConnect, I_OnChangeHost };
ServerInstance->Modules->Attach(eventlist, this, sizeof(eventlist)/sizeof(Implementation));
if (!Hash)
throw CoreException("Cannot find hash/md5: did you load the m_md5.so module?");
}
/** 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);
}
/**
* 1.2-style cloaking function
* @param table The table to use (will be used mod 4, not a secure parameter)
* @param data The item to cloak
* @param bytes The number of bytes in the output (output is double this size)
*/
std::string sumIV(int table, const std::string& data, int bytes)
{
std::string bits = Hash->sum(data, compatkey);
const char* hex = xtab[table % 4];
std::string rv;
for(int i=0; i < bytes; i++)
{
unsigned char v = bits[i];
rv.push_back(hex[v / 16]);
rv.push_back(hex[v % 16]);
}
return rv;
}
std::string CompatCloak4(const char* ip)
{
irc::sepstream seps(ip, '.', false);
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 */
std::string rv;
/* Send the Hash module a different hex table for each octet group's Hash sum */
for (int k = 0; k < 4; k++)
{
rv.append(sumIV(compatkey[k]+i[k], octet[k], 3));
if (k < 3)
rv.append(".");
}
/* Stick them all together */
return rv;
}
std::string CompatCloak6(const char* ip)
{
std::vector<std::string> hashies;
std::string item;
int rounds = 0;
/* Reset the Hash module and send it our IV */
for (const char* input = ip; *input; input++)
{
item += *input;
if (item.length() > 7)
{
hashies.push_back(sumIV(compatkey[0]+rounds, item, 4));
item.clear();
}
rounds++;
}
if (!item.empty())
{
hashies.push_back(sumIV(compatkey[0]+rounds, item, 4));
}
/* Stick them all together */
return irc::stringjoiner(":", hashies, 0, hashies.size() - 1).GetJoined();
}
ModResult OnCheckBan(User* user, Channel* chan, const std::string& mask)
{
LocalUser* lu = IS_LOCAL(user);
if (!lu)
return MOD_RES_PASSTHRU;
OnUserConnect(lu);
std::string* cloak = cu.ext.get(user);
/* Check if they have a cloaked host, but are not using it */
if (cloak && *cloak != user->dhost)
{
char cmask[MAXBUF];
snprintf(cmask, MAXBUF, "%s!%s@%s", user->nick.c_str(), user->ident.c_str(), cloak->c_str());
if (InspIRCd::Match(cmask,mask))
return MOD_RES_DENY;
}
return MOD_RES_PASSTHRU;
}
void Prioritize()
{
/* Needs to be after m_banexception etc. */
ServerInstance->Modules->SetPriority(this, I_OnCheckBan, PRIORITY_LAST);
}
// this unsets umode +x on every host change. If we are actually doing a +x
// mode change, we will call SetMode back to true AFTER the host change is done.
void OnChangeHost(User* u, const std::string& host)
{
if(u->IsModeSet('x'))
{
u->SetMode('x', false);
u->WriteServ("MODE %s -x", u->nick.c_str());
}
}
~ModuleCloaking()
{
}
Version GetVersion()
{
std::string testcloak = "broken";
if (Hash)
{
switch (mode)
{
case MODE_COMPAT_HOST:
testcloak = prefix + "-" + sumIV(0, "*", 5);
break;
case MODE_COMPAT_IPONLY:
testcloak = sumIV(0, "*", 5);
break;
}
}
return Version("Provides masking of user hostnames", VF_COMMON|VF_VENDOR, testcloak);
}
void ReadConfig(ConfigReadStatus& stat)
{
ConfigTag* tag = ServerInstance->Config->GetTag("cloak");
prefix = tag->getString("prefix");
std::string modestr = tag->getString("mode");
mode = tag->getBool("ipalways") ? MODE_COMPAT_IPONLY : MODE_COMPAT_HOST;
if (modestr == "compat-host")
mode = MODE_COMPAT_HOST;
else if (modestr == "compat-ip")
mode = MODE_COMPAT_IPONLY;
else if (modestr != "")
stat.ReportError(tag, "Bad value for <cloak:mode>; must be compat-host or compat-ip");
bool lowercase = tag->getBool("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
*
* We must limit the keys or else we get different results on
* amd64/x86 boxes. - psychon */
const unsigned int limit = 0x80000000;
compatkey[0] = (unsigned int) tag->getInt("key1");
compatkey[1] = (unsigned int) tag->getInt("key2");
compatkey[2] = (unsigned int) tag->getInt("key3");
compatkey[3] = (unsigned int) tag->getInt("key4");
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;
const char* detail = NULL;
if (!compatkey[0] || compatkey[0] >= limit)
detail = "<cloak:key1> is not valid, it may be set to a too high/low value, or it may not exist.";
else if (!compatkey[1] || compatkey[1] >= limit)
detail = "<cloak:key2> is not valid, it may be set to a too high/low value, or it may not exist.";
else if (!compatkey[2] || compatkey[2] >= limit)
detail = "<cloak:key3> is not valid, it may be set to a too high/low value, or it may not exist.";
else if (!compatkey[3] || compatkey[3] >= limit)
detail = "<cloak:key4> is not valid, it may be set to a too high/low value, or it may not exist.";
if (detail)
stat.ReportError(tag, detail);
}
std::string GenCloak(const irc::sockets::sockaddrs& ip, const std::string& ipstr, const std::string& host)
{
std::string chost;
switch (mode)
{
case MODE_COMPAT_HOST:
{
if (ipstr != host)
{
std::string tail = LastTwoDomainParts(host);
// sumIV is not used here due to a bug in 1.2 cloaking
chost = prefix + "-" + irc::hex((const unsigned char*)Hash->sum(host, compatkey).data(), 4) + tail;
/* Fix by brain - if the cloaked host is > the max length of a host (64 bytes
* according to the DNS RFC) then they get cloaked as an IP.
*/
if (chost.length() <= 64)
break;
}
// fall through to IP cloak
}
default:
if (ip.sa.sa_family == AF_INET6)
chost = CompatCloak6(ipstr.c_str());
else
chost = CompatCloak4(ipstr.c_str());
}
return chost;
}
void OnUserConnect(LocalUser* dest)
{
std::string* cloak = cu.ext.get(dest);
if (cloak)
return;
cu.ext.set(dest, GenCloak(dest->client_sa, dest->GetIPString(), dest->host));
}
};
CmdResult CommandCloak::Handle(const std::vector<std::string> ¶meters, User *user)
{
ModuleCloaking* mod = (ModuleCloaking*)(Module*)creator;
irc::sockets::sockaddrs sa;
std::string cloak;
if (irc::sockets::aptosa(parameters[0], 0, sa))
cloak = mod->GenCloak(sa, parameters[0], parameters[0]);
else
cloak = mod->GenCloak(sa, "", parameters[0]);
user->WriteServ("NOTICE %s :*** Cloak for %s is %s", user->nick.c_str(), parameters[0].c_str(), cloak.c_str());
return CMD_SUCCESS;
}
}
using cloak_12::ModuleCloaking;
MODULE_INIT(ModuleCloaking)
