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Retail products

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Traffic interception SDK

Control every TCP/IP network connection

• Route connections via proxy
• Redirect connections and modify the data
• Block connections and applications

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SSL interception SDK

View SSL in plaintext and modify it

• View the SSL stream decrypted in plaintext
• Redirect SSL connection and modify decrypted data
• Browser shows "SSL lock" without warnings

Learn More

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Documentation

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DNSParser.cpp Go to the documentation of this file. /* * Copyright (c) 2000-2003 Barak Weichselbaum <barak@komodia.com> * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * Contact info: * ------------- * * Site: http://www.komodia.com * Main contact: barak@komodia.com * For custom projects, * consulting, or other * paid services: sales@komodia.com */ #include "stdafx.h" #include "DNSParser.h" #include "ErrorHandlerMacros.h" #include "Array_ptr.h" #ifdef _MEMORY_DEBUG #define new DEBUG_NEW #define malloc DEBUG_MALLOC static char THIS_FILE[] = __FILE__; #endif namespace KomodiaDNS { #define CDNSParser_Class "CDNSParser" #define MAX_REPLY 2000 #define MAX_DOMAIN_SIZE 1024 CDNSParser::CDNSParser() : CErrorHandler() { try { //Set our name SetName(CDNSParser_Class); } ERROR_HANDLER("CDNSParser") } CDNSParser::~CDNSParser() { } std::string CDNSParser::ParseName(const char* pBuffer, const char* pOriginalBuffer, unsigned short& rLength) { try { //Set the length to zero rLength=0; //Damn shortcuts unsigned short usShort; usShort=*((unsigned short*)pBuffer); //Convert it usShort=htons(usShort); //Check for shortcuts if (usShort & 0xc000) { //Remove the traling bits usShort=usShort & 0x3fff; //Get length of the domain unsigned short usLength; usLength=GetParsedDomainLength(pOriginalBuffer+usShort, pOriginalBuffer); //Check for errors if (!usLength) { //Report it ReportStaticError(CDNSParser_Class,"ParseName","Received zero length!"); //Exit return ""; } else { //Set the length to parsed rLength=2; //Returned the parsed name return ConvertParsedName(pOriginalBuffer+usShort, pOriginalBuffer); } } else { //Regular name //Get length of the domain unsigned short usLength; usLength=GetParsedDomainLength(pBuffer, pOriginalBuffer); //Check for errors if (!usLength) { //Report it ReportStaticError(CDNSParser_Class,"ParseName","Received zero length!"); //Exit return ""; } else { //Set the length rLength=usLength; //Returned the parsed data return ConvertParsedName(pBuffer, pOriginalBuffer); } } } ERROR_HANDLER_STATIC_RETURN(CDNSParser_Class,"ParseName","") } unsigned short CDNSParser::GetParsedDomainLength(const char *pBuffer, const char* pOriginalBuffer) { try { //Get the length of the parsed domain const unsigned char* pBackupBuffer=(const unsigned char*)pBuffer; //Counter unsigned short usCounter; usCounter=0; while (*pBackupBuffer && usCounter<256) { if (pOriginalBuffer) { //Damn shortcuts unsigned short usShort; usShort=*((unsigned short*)pBackupBuffer); //Convert it usShort=htons(usShort); //Check for shortcuts if (usShort & 0xc000) { //Remove the traling bits usShort=usShort & 0x3fff; //Check the size if (usShort>MAX_REPLY) { //Report it ReportStaticError(CDNSParser_Class,"GetParsedDomainLength","Size too big!"); //Exit return 0; } //Get length of the domain unsigned short usLength; usLength=GetParsedDomainLength(pOriginalBuffer+usShort, pOriginalBuffer); //Check for errors if (!usLength) { //Report it ReportStaticError(CDNSParser_Class,"GetParsedDomainLength","Received zero length!"); //Exit return 0; } else { //We are done usCounter+=usLength; //And exit return usCounter+1; } } } //Regular usCounter+=*pBackupBuffer+1; pBackupBuffer+=*pBackupBuffer+1; } //Check for errors if (usCounter>256) { //Report it ReportStaticError(CDNSParser_Class,"GetParsedDomainLength","Recieved length too high!"); //Exit return 0; } else return usCounter+1; } ERROR_HANDLER_STATIC_RETURN(CDNSParser_Class,"GetParsedDomainLength",0) } std::string CDNSParser::ConvertParsedName(const char* pBuffer, const char* pOriginalBuffer) { try { //Our string std::string sParsedName; //Counter unsigned short usCounter; usCounter=0; while (*pBuffer && usCounter<MAX_DOMAIN_SIZE) { if (pOriginalBuffer) { //Damn shortcuts unsigned short usShort; usShort=*((const unsigned short*)pBuffer); //Convert it usShort=htons(usShort); //Check for shortcuts if (usShort & 0xc000) { //Remove the traling bits usShort=usShort & 0x3fff; //Check the size if (usShort>MAX_REPLY) { //Report it ReportStaticError(CDNSParser_Class,"ConvertParsedName","Size too big!"); //Exit return 0; } //Get length of the domain unsigned short usLength; usLength=GetParsedDomainLength(pOriginalBuffer+usShort, pOriginalBuffer); //Check for errors if (!usLength) { //Report it ReportStaticError(CDNSParser_Class,"ConvertParsedName","Recieved zero length!"); //Exit return ""; } else //Continue parsing pBuffer=pOriginalBuffer+usShort; } } //Get the section length unsigned short usLength; usLength=*pBuffer; //Point it to the next byte ++pBuffer; //Copy it to tmp variable CArray_ptr<char> pTmpData(new char[usLength+1]); memcpy(pTmpData.Get(), pBuffer, usLength); //Terminate it pTmpData.Get()[usLength]=0; //Add it to our string sParsedName+=pTmpData.Get(); //Increment the buffer pBuffer+=usLength; //Check if not the latest byte if (*pBuffer) //Add the dot sParsedName+='.'; } //Check for errors if (usCounter>MAX_DOMAIN_SIZE) { //Report it ReportStaticError(CDNSParser_Class,"ConvertParsedName","Recieved size too large!"); //Exit return ""; } else //Done return sParsedName; } ERROR_HANDLER_STATIC_RETURN(CDNSParser_Class,"ConvertParsedName","") } std::string CDNSParser::ConvertName(const std::string& rName) { try { //Length unsigned short usLength; //The string std::string sAnswer; sAnswer=ParseName(rName.c_str(), rName.c_str(), usLength); //What we have if (usLength) return sAnswer; else return ""; } ERROR_HANDLER_STATIC_RETURN(CDNSParser_Class,"ConvertName","") } //of namespace }

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