~vcs-imports-ii/znc/master

/*

 * Copyright (C) 2004-2013 ZNC, see the NOTICE file for details.

 *

 * Licensed under the Apache License, Version 2.0 (the "License");

 * you may not use this file except in compliance with the License.

 * You may obtain a copy of the License at

 *

 *     http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

//! @author prozac@rottenboy.com

//

// The encryption here was designed to be compatible with mircryption's CBC mode.

//

// TODO:

//

// 1) Encrypt key storage file

// 2) Secure key exchange using pub/priv keys and the DH algorithm

// 3) Some way of notifying the user that the current channel is in "encryption mode" verses plain text

// 4) Temporarily disable a target (nick/chan)

//

// NOTE: This module is currently NOT intended to secure you from your shell admin.

//       The keys are currently stored in plain text, so anyone with access to your account (or root) can obtain them.

//       It is strongly suggested that you enable SSL between znc and your client otherwise the encryption stops at znc and gets sent to your client in plain text.

//

#include <znc/Chan.h>

#include <znc/User.h>

#include <znc/IRCNetwork.h>

#define REQUIRESSL	1

#define NICK_PREFIX_KEY	"[nick-prefix]"

class CCryptMod : public CModule {

	CString NickPrefix() {

		MCString::iterator it = FindNV(NICK_PREFIX_KEY);

		return it != EndNV() ? it->second : "*";

	}

public:

	MODCONSTRUCTOR(CCryptMod) {}

	virtual ~CCryptMod() {}

	virtual EModRet OnUserMsg(CString& sTarget, CString& sMessage) {

		sTarget.TrimLeft(NickPrefix());

		if (sMessage.Left(2) == "``") {

			sMessage.LeftChomp(2);

			return CONTINUE;

		}

		MCString::iterator it = FindNV(sTarget.AsLower());

		if (it != EndNV()) {

			CChan* pChan = m_pNetwork->FindChan(sTarget);

			if (pChan) {

				if (!pChan->AutoClearChanBuffer())

					pChan->AddBuffer(":" + NickPrefix() + _NAMEDFMT(m_pNetwork->GetIRCNick().GetNickMask()) + " PRIVMSG " + _NAMEDFMT(sTarget) + " :{text}", sMessage);

				m_pUser->PutUser(":" + NickPrefix() + m_pNetwork->GetIRCNick().GetNickMask() + " PRIVMSG " + sTarget + " :" + sMessage, NULL, m_pClient);

			}

			CString sMsg = MakeIvec() + sMessage;

			sMsg.Encrypt(it->second);

			sMsg.Base64Encode();

			sMsg = "+OK *" + sMsg;

			PutIRC("PRIVMSG " + sTarget + " :" + sMsg);

			return HALTCORE;

		}

		return CONTINUE;

	}

	virtual EModRet OnPrivMsg(CNick& Nick, CString& sMessage) {

		FilterIncoming(Nick.GetNick(), Nick, sMessage);

		return CONTINUE;

	}

	virtual EModRet OnChanMsg(CNick& Nick, CChan& Channel, CString& sMessage) {

		FilterIncoming(Channel.GetName(), Nick, sMessage);

		return CONTINUE;

	}

	void FilterIncoming(const CString& sTarget, CNick& Nick, CString& sMessage) {

		if (sMessage.Left(5) == "+OK *") {

			MCString::iterator it = FindNV(sTarget.AsLower());

			if (it != EndNV()) {

				sMessage.LeftChomp(5);

				sMessage.Base64Decode();

				sMessage.Decrypt(it->second);

				sMessage.LeftChomp(8);

				sMessage = sMessage.c_str();

				Nick.SetNick(NickPrefix() + Nick.GetNick());

			}

		}

	}

	virtual void OnModCommand(const CString& sCommand) {

		CString sCmd = sCommand.Token(0);

		if (sCmd.Equals("DELKEY")) {

			CString sTarget = sCommand.Token(1);

			if (!sTarget.empty()) {

				if (DelNV(sTarget.AsLower())) {

					PutModule("Target [" + sTarget + "] deleted");

				} else {

					PutModule("Target [" + sTarget + "] not found");

				}

			} else {

				PutModule("Usage DelKey <#chan|Nick>");

			}

		} else if (sCmd.Equals("SETKEY")) {

			CString sTarget = sCommand.Token(1);

			CString sKey = sCommand.Token(2, true);

			// Strip "cbc:" from beginning of string incase someone pastes directly from mircryption

			sKey.TrimPrefix("cbc:");

			if (!sKey.empty()) {

				SetNV(sTarget.AsLower(), sKey);

				PutModule("Set encryption key for [" + sTarget + "] to [" + sKey + "]");

			} else {

				PutModule("Usage: SetKey <#chan|Nick> <Key>");

			}

		} else if (sCmd.Equals("LISTKEYS")) {

			if (BeginNV() == EndNV()) {

				PutModule("You have no encryption keys set.");

			} else {

				CTable Table;

				Table.AddColumn("Target");

				Table.AddColumn("Key");

				for (MCString::iterator it = BeginNV(); it != EndNV(); ++it) {

					Table.AddRow();

					Table.SetCell("Target", it->first);

					Table.SetCell("Key", it->second);

				}

				MCString::iterator it = FindNV(NICK_PREFIX_KEY);

				if (it == EndNV()) {

					Table.AddRow();

					Table.SetCell("Target", NICK_PREFIX_KEY);

					Table.SetCell("Key", NickPrefix());

				}

				PutModule(Table);

			}

		} else if (sCmd.Equals("HELP")) {

			PutModule("Try: SetKey, DelKey, ListKeys");

		} else {

			PutModule("Unknown command, try 'Help'");

		}

	}

	CString MakeIvec() {

		CString sRet;

		time_t t;

		time(&t);

		int r = rand();

		sRet.append((char*) &t, 4);

		sRet.append((char*) &r, 4);

		return sRet;

	}

};

template<> void TModInfo<CCryptMod>(CModInfo& Info) {

	Info.SetWikiPage("crypt");

}

NETWORKMODULEDEFS(CCryptMod, "Encryption for channel/private messages")