1
|
/* +------------------------------------+
* | Inspire Internet Relay Chat Daemon |
* +------------------------------------+
*
* InspIRCd: (C) 2002-2007 InspIRCd Development Team
* See: http://www.inspircd.org/wiki/index.php/Credits
*
* This program is free but copyrighted software; see
* the file COPYING for details.
*
* ---------------------------------------------------
*/
#include "inspircd.h"
#include "users.h"
#include "channels.h"
#include "modules.h"
#include "m_hash.h"
/* $ModDesc: Provides masking of user hostnames */
/* $ModDep: m_hash.h */
/* Used to vary the output a little more depending on the cloak keys */
static const char* xtab[] = {"F92E45D871BCA630", "A1B9D80C72E653F4", "1ABC078934DEF562", "ABCDEF5678901234"};
/** Handles user mode +x
*/
class CloakUser : public ModeHandler
{
std::string prefix;
unsigned int key1;
unsigned int key2;
unsigned int key3;
unsigned int key4;
Module* Sender;
Module* HashProvider;
/** 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 host;
else
return host.substr(splitdot);
}
public:
CloakUser(InspIRCd* Instance, Module* Source, Module* Hash) : ModeHandler(Instance, 'x', 0, 0, false, MODETYPE_USER, false), Sender(Source), HashProvider(Hash)
{
}
ModeAction OnModeChange(userrec* source, userrec* dest, chanrec* channel, std::string ¶meter, bool adding)
{
if (source != dest)
return MODEACTION_DENY;
/* For remote clients, we dont take any action, we just allow it.
* The local server where they are will set their cloak instead.
*/
if (!IS_LOCAL(dest))
return MODEACTION_ALLOW;
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.
*/
char* n1 = strchr(dest->host,'.');
char* n2 = strchr(dest->host,':');
if (n1 || n2)
{
/* 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.
*/
unsigned int iv[] = { key1, key2, key3, key4 };
std::string a = LastTwoDomainParts(dest->host);
std::string b;
/** Reset the Hash module, and send it our IV and hex table */
HashResetRequest(Sender, HashProvider).Send();
HashKeyRequest(Sender, HashProvider, iv).Send();
HashHexRequest(Sender, HashProvider, xtab[(*dest->host) % 4]);
/* Generate a cloak using specialized Hash */
std::string hostcloak = prefix + "-" + std::string(HashSumRequest(Sender, HashProvider, dest->host).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,&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,&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,':')) ? Cloak4(dest->host) : Cloak6(dest->host));
#else
in_addr testaddr;
if ((inet_aton(dest->host,&testaddr) < 1) && (hostcloak.length() <= 64))
/* Invalid ipv4 address, and ipv4 user (resolved host) */
b = hostcloak;
else
/* Valid ipv4 address (not resolved) ipv4 user */
b = Cloak4(dest->host);
#endif
dest->ChangeDisplayedHost(b.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);
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++)
{
octet[j] = seps.GetToken();
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)
{
/* Theyre using 4in6 (YUCK). Translate as ipv4 cloak */
if (!strncmp(ip, "0::ffff:", 8))
return Cloak4(ip + 8);
/* If we get here, yes it really is an ipv6 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);
key1 = key2 = key3 = key4 = 0;
key1 = Conf.ReadInteger("cloak","key1",0,true);
key2 = Conf.ReadInteger("cloak","key2",0,true);
key3 = Conf.ReadInteger("cloak","key3",0,true);
key4 = Conf.ReadInteger("cloak","key4",0,true);
prefix = Conf.ReadValue("cloak","prefix",0);
if (prefix.empty())
prefix = ServerInstance->Config->Network;
if (!key1 && !key2 && !key3 && !key4)
throw ModuleException("You have not defined cloak keys for m_cloaking!!! THIS IS INSECURE AND SHOULD BE CHECKED!");
}
};
class ModuleCloaking : public Module
{
private:
CloakUser* cu;
Module* HashModule;
public:
ModuleCloaking(InspIRCd* Me)
: Module(Me)
{
ServerInstance->UseInterface("HashRequest");
/* Attempt to locate the md5 service provider, bail if we can't find it */
HashModule = ServerInstance->FindModule("m_md5.so");
if (!HashModule)
throw ModuleException("Can't find m_md5.so. Please load m_md5.so before m_cloaking.so.");
/* Create new mode handler object */
cu = new CloakUser(ServerInstance, this, HashModule);
/* Register it with the core */
if (!ServerInstance->AddMode(cu, 'x'))
throw ModuleException("Could not add new modes!");
OnRehash(NULL,"");
}
virtual ~ModuleCloaking()
{
ServerInstance->Modes->DelMode(cu);
DELETE(cu);
ServerInstance->DoneWithInterface("HashRequest");
}
virtual Version GetVersion()
{
// returns the version number of the module to be
// listed in /MODULES
return Version(1,1,0,2,VF_COMMON|VF_VENDOR,API_VERSION);
}
virtual void OnRehash(userrec* user, const std::string ¶meter)
{
cu->DoRehash();
}
void Implements(char* List)
{
List[I_OnRehash] = 1;
}
};
MODULE_INIT(ModuleCloaking)
|
