// <edit>
#include "linden_common.h"
#include "llimagemetadatareader.h"
#include "aes.h"
const unsigned long EMKDU_AES_KEY[] = {0x7810001, 0x0FEB67863, 0x12B03F6E, 0x0C16665CC, 0x0C1AC9681, 0x0F70B663B};
//const unsigned char EMKDU_AES_KEY[] = {0x01,0x00,0x81,0x07,0x63,0x78,0xB6,0xFE,0x6E,0x3F,0xB0,0x12,0xCC,0x65,0x66,0xC1,
//0x81,0x96,0xAC,0xC1,0x3B,0x66,0x0B,0xF7};
//#define COMMENT_DEBUGG1ING
LLJ2cParser::LLJ2cParser(U8* data,int data_size)
{
    	if(data && data_size)
	{
		mData.resize(data_size);
		memcpy(&(mData[0]), data, data_size);
		//std::copy(data,data+data_size,mData.begin());
	}
	mIter = mData.begin();
}

U8 LLJ2cParser::nextChar()
{
	U8 rtn = 0x00;
	if(mIter != mData.end())
	{
		rtn = (*mIter);
		mIter++;
	}
	return rtn;
}

std::vector<U8> LLJ2cParser::nextCharArray(int len)
{
	std::vector<U8> array;
	if(len > 0)
	{
		array.resize(len);
		for(S32 i = 0; i < len; i++)
		{
			array[i] = nextChar();
		}
	}
	return array;
}

std::vector<U8> LLJ2cParser::GetNextComment()
{
	std::vector<U8> content;
	while (mIter != mData.end())
	{
		U8 marker = nextChar();
		if (marker == 0xff)
		{
		    U8 marker_type = nextChar();
		    if (marker_type == 0x4f)
		    {
				continue;
		    }
		    if (marker_type == 0x90)
		    {
				//llinfos << "FOUND 0x90" << llendl;
				break; //return empty vector
		    }
		    
		    if (marker_type == 0x64)
		    {
				//llinfos << "FOUND 0x64 COMMENT SECTION" << llendl;
				S32 len = ((S32)nextChar())*256 + (S32)nextChar();
		   		if (len > 3) content = nextCharArray(len - 2);
				return content;
		    }
		}
	}
	content.clear(); //return empty vector by clear anything there
	return content;
}

//static
std::string LLImageMetaDataReader::ExtractEncodedComment(U8* data,int data_size)
{
	LLJ2cParser parser = LLJ2cParser(data,data_size);
	std::string result;
	while(1)
	{
	    std::vector<U8> comment = parser.GetNextComment();
	    if (comment.empty()) break; //exit loop
	    if (comment[1] == 0x00 && comment.size() == 130)
	    {
			bool xorComment = true;
			//llinfos << "FOUND PAYLOAD" << llendl;
			std::vector<U8> payload(128);
			S32 i;
			memcpy(&(payload[0]), &(comment[2]), 128);
			//std::copy(comment.begin()+2,comment.end(),payload.begin());
			//lets check XOR Cipher first
			if (payload[2] == payload[127])
			{
				// emkdu.dll
				for (i = 4; i < 128; i += 4)
				{
					payload[i] ^= payload[3];
					payload[i + 1] ^= payload[1];
					payload[i + 2] ^= payload[0];
					payload[i + 3] ^= payload[2];
				}
			}
			else if (payload[3] == payload[127])
			{
				// emkdu.dll or onyxkdu.dll
				for (i = 4; i < 128; i += 4)
				{
					payload[i] ^= payload[2];
					payload[i + 1] ^= payload[0];
					payload[i + 2] ^= payload[1];
					payload[i + 3] ^= payload[3];
				}
			}
			else
			{
				xorComment = false;
			}
			if(!xorComment)
			{
				//this is terrible i know
				std::vector<U8> dataout(128);
				AES aes;
				aes.SetParameters(192);
				aes.StartDecryption(reinterpret_cast<const unsigned char*>(EMKDU_AES_KEY));
				aes.Decrypt(&(payload[0]),&(dataout[0]),16);
				//payload.clear();
				//memcpy(&(payload[0]),&(dataout[0]),dataout.size());
				for (i = 0 ; i < 128; ++i)
				{
					if (dataout[i] == 0) break;
				}
				if(i == 0) continue;
				if(result.length() > 0)
					result.append(" ");
				result.assign(dataout.begin(),dataout.begin()+i);
			}
			else
			{
				for (i = 4 ; i < 128; ++i)
				{
					if (payload[i] == 0) break;
				}
				if(i < 4) continue;
				if(result.length() > 0)
					result.append(" ");
				result.append(payload.begin()+4,payload.begin()+i);
			}
			//llinfos << "FOUND COMMENT: " << result << llendl;
	    }
	}
	//end of loop
	return result;
}
// </edit>