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/*
* InspIRCd -- Internet Relay Chat Daemon
*
* Copyright (C) 2017-2019 Sadie Powell <sadie@witchery.services>
*
* 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 "modules/cap.h"
#include "modules/ssl.h"
class STSCap : public Cap::Capability
{
private:
std::string host;
std::string plaintextpolicy;
std::string securepolicy;
bool OnList(LocalUser* user) CXX11_OVERRIDE
{
// Don't send the cap to clients that only support cap-3.1.
if (GetProtocol(user) == Cap::CAP_LEGACY)
return false;
// Don't send the cap to clients in a class which has STS disabled.
if (!user->GetClass()->config->getBool("usests", true))
return false;
// Plaintext listeners have their own policy.
SSLIOHook* sslhook = SSLIOHook::IsSSL(&user->eh);
if (!sslhook)
return true;
// If no hostname has been provided for the connection, an STS persistence policy SHOULD NOT be advertised.
std::string snihost;
if (!sslhook->GetServerName(snihost))
return false;
// Before advertising an STS persistence policy over a secure connection, servers SHOULD verify whether the
// hostname provided by clients, for example, via TLS Server Name Indication (SNI), has been whitelisted by
// administrators in the server configuration.
return InspIRCd::Match(snihost, host, ascii_case_insensitive_map);
}
bool OnRequest(LocalUser* user, bool adding) CXX11_OVERRIDE
{
// Clients MUST NOT request this capability with CAP REQ. Servers MAY reply with a CAP NAK message if a
// client requests this capability.
return false;
}
const std::string* GetValue(LocalUser* user) const CXX11_OVERRIDE
{
return SSLIOHook::IsSSL(&user->eh) ? &securepolicy : &plaintextpolicy;
}
public:
STSCap(Module* mod)
: Cap::Capability(mod, "sts")
{
}
~STSCap()
{
// TODO: Send duration=0 when STS vanishes.
}
void SetPolicy(const std::string& newhost, unsigned long duration, unsigned int port, bool preload)
{
// To enforce an STS upgrade policy, servers MUST send this key to insecurely connected clients. Servers
// MAY send this key to securely connected clients, but it will be ignored.
std::string newplaintextpolicy("port=");
newplaintextpolicy.append(ConvToStr(port));
// To enforce an STS persistence policy, servers MUST send this key to securely connected clients. Servers
// MAY send this key to all clients, but insecurely connected clients MUST ignore it.
std::string newsecurepolicy("duration=");
newsecurepolicy.append(ConvToStr(duration));
// Servers MAY send this key to all clients, but insecurely connected clients MUST ignore it.
if (preload)
newsecurepolicy.append(",preload");
// Apply the new policy.
bool changed = false;
if (!irc::equals(host, newhost))
{
ServerInstance->Logs->Log(MODNAME, LOG_DEBUG, "Changing STS SNI hostname from \"%s\" to \"%s\"", host.c_str(), newhost.c_str());
host = newhost;
changed = true;
}
if (plaintextpolicy != newplaintextpolicy)
{
ServerInstance->Logs->Log(MODNAME, LOG_DEBUG, "Changing plaintext STS policy from \"%s\" to \"%s\"", plaintextpolicy.c_str(), newplaintextpolicy.c_str());
plaintextpolicy.swap(newplaintextpolicy);
changed = true;
}
if (securepolicy != newsecurepolicy)
{
ServerInstance->Logs->Log(MODNAME, LOG_DEBUG, "Changing secure STS policy from \"%s\" to \"%s\"", securepolicy.c_str(), newsecurepolicy.c_str());
securepolicy.swap(newsecurepolicy);
changed = true;
}
// If the policy has changed then notify all clients via cap-notify.
if (changed)
NotifyValueChange();
}
};
class ModuleIRCv3STS : public Module
{
private:
STSCap cap;
// The IRCv3 STS specification requires that the server is listening using SSL using a valid certificate.
bool HasValidSSLPort(unsigned int port)
{
for (std::vector<ListenSocket*>::const_iterator iter = ServerInstance->ports.begin(); iter != ServerInstance->ports.end(); ++iter)
{
ListenSocket* ls = *iter;
// Is this listener on the right port?
unsigned int saport = ls->bind_sa.port();
if (saport != port)
continue;
// Is this listener using SSL?
if (ls->bind_tag->getString("ssl").empty())
continue;
// TODO: Add a way to check if a listener's TLS cert is CA-verified.
return true;
}
return false;
}
public:
ModuleIRCv3STS()
: cap(this)
{
}
void ReadConfig(ConfigStatus& status) CXX11_OVERRIDE
{
// TODO: Multiple SNI profiles
ConfigTag* tag = ServerInstance->Config->ConfValue("sts");
if (tag == ServerInstance->Config->EmptyTag)
throw ModuleException("You must define a STS policy!");
const std::string host = tag->getString("host");
if (host.empty())
throw ModuleException("<sts:host> must contain a hostname, at " + tag->getTagLocation());
unsigned int port = tag->getUInt("port", 0, 0, UINT16_MAX);
if (!HasValidSSLPort(port))
throw ModuleException("<sts:port> must be a TLS port, at " + tag->getTagLocation());
unsigned long duration = tag->getDuration("duration", 60*60*24*30*2);
bool preload = tag->getBool("preload");
cap.SetPolicy(host, duration, port, preload);
}
Version GetVersion() CXX11_OVERRIDE
{
return Version("Provides IRCv3 Strict Transport Security policy advertisement", VF_OPTCOMMON|VF_VENDOR);
}
};
MODULE_INIT(ModuleIRCv3STS)
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