eqemu-server/common/packet_functions.cpp

/*	EQEmu: EQEmulator

	Copyright (C) 2001-2026 EQEmu Development Team

	This program 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; either version 3 of the License, or
	(at your option) any later version.

	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 "packet_functions.h"

#include "common/packet_dump.h"
#include "common/platform/inet.h"

#include "zlib.h"
#include <cstring>
#include <iostream>

void EncryptProfilePacket(EQApplicationPacket* app) {
	//EncryptProfilePacket(app->pBuffer, app->size);
}

void EncryptProfilePacket(uchar* pBuffer, uint32 size) {
	uint64* data=(uint64*)pBuffer;
	uint64 crypt = 0x659365E7;
	uint64 next_crypt;
	uint32 len = size >> 3;

	uint64 swap = data[0];
	data[0] = data[len/2];
	data[len/2] = swap;

	for(uint32 i=0; i<len;i++) {
		next_crypt = crypt+data[i]-0x422437A9;
		data[i] = ((data[i]>>0x19)|(data[i]<<0x27))+0x422437A9;
		data[i] = (data[i]<<0x07)|(data[i]>>0x39);
		data[i] = data[i] - crypt;
		crypt = next_crypt;
	}
}

void EncryptZoneSpawnPacket(EQApplicationPacket* app) {
	//EncryptZoneSpawnPacket(app->pBuffer, app->size);
}

void EncryptZoneSpawnPacket(uchar* pBuffer, uint32 size) {
	uint64* data=(uint64*)pBuffer;
	uint64 crypt = 0x0000;
	uint64 next_crypt;
	uint32 len = size >> 3;

	uint64 swap = data[0];
	data[0] = data[len/2];
	data[len/2] = swap;

	for(uint32 i=0; i<len;i++) {
		next_crypt = crypt+data[i]-0x659365E7;
		data[i] = ((data[i]<<0x1d)|(data[i]>>0x23))+0x659365E7;
		data[i] = (data[i]<<0x0e)|(data[i]>>0x32);
		data[i] = data[i] - crypt;
		crypt = next_crypt;
	}
}

#define MEMORY_DEBUG

#ifndef MEMORY_DEBUG
#define eqemu_alloc_func Z_NULL
#define eqemu_free_func Z_NULL
#else
//These functions only exist to make my memory profiler
voidpf eqemu_alloc_func(voidpf opaque, uInt items, uInt size);
void eqemu_free_func(voidpf opaque, voidpf address);

voidpf eqemu_alloc_func(voidpf opaque, uInt items, uInt size) {
	voidpf tmp = new char[items*size];
	return(tmp);
}

void eqemu_free_func(voidpf opaque, voidpf address) {
	delete[] (char *)address;
}
#endif


int DeflatePacket(const unsigned char* in_data, int in_length, unsigned char* out_data, int max_out_length) {
#ifdef REUSE_ZLIB
	static bool inited = false;
	static z_stream zstream;
	int zerror;

	if(in_data == nullptr && out_data == nullptr && in_length == 0 && max_out_length == 0) {
		//special delete state
		deflateEnd(&zstream);
		return(0);
	}
	if(!inited) {
		memset(&zstream, 0, sizeof(zstream));
		zstream.zalloc	= eqemu_alloc_func;
		zstream.zfree	= eqemu_free_func;
		zstream.opaque	= Z_NULL;
		deflateInit(&zstream, Z_FINISH);
	}

	zstream.next_in		= const_cast<unsigned char *>(in_data);
	zstream.avail_in	= in_length;
/*	zstream.zalloc	= Z_NULL;
	zstream.zfree	= Z_NULL;
	zstream.opaque	= Z_NULL;
	deflateInit(&zstream, Z_FINISH);*/
	zstream.next_out = out_data;
	zstream.avail_out = max_out_length;
	zerror = deflate(&zstream, Z_FINISH);

	deflateReset(&zstream);

	if (zerror == Z_STREAM_END)
	{
//		deflateEnd(&zstream);
		return zstream.total_out;
	}
	else
	{
//		zerror = deflateEnd(&zstream);
		return 0;
	}
#else
	if(in_data == nullptr) {
		return(0);
	}

	z_stream zstream;
	memset(&zstream, 0, sizeof(zstream));
	int zerror;

	zstream.next_in		= const_cast<unsigned char *>(in_data);
	zstream.avail_in	= in_length;
	zstream.zalloc	= eqemu_alloc_func;
	zstream.zfree	= eqemu_free_func;
	zstream.opaque	= Z_NULL;
	deflateInit(&zstream, Z_FINISH);
	zstream.next_out = out_data;
	zstream.avail_out = max_out_length;
	zerror = deflate(&zstream, Z_FINISH);

	if (zerror == Z_STREAM_END)
	{
		deflateEnd(&zstream);
		return zstream.total_out;
	}
	else
	{
		zerror = deflateEnd(&zstream);
		return 0;
	}
#endif
}

uint32 InflatePacket(const uchar* indata, uint32 indatalen, uchar* outdata, uint32 outdatalen, bool iQuiet) {
#ifdef REUSE_ZLIB
	static bool inited = false;
	static z_stream zstream;
	int zerror;

	if(indata == nullptr && outdata == nullptr && indatalen == 0 && outdatalen == 0) {
		//special delete state
		inflateEnd(&zstream);
		return(0);
	}
	if(!inited) {
		zstream.zalloc	= eqemu_alloc_func;
		zstream.zfree	= eqemu_free_func;
		zstream.opaque	= Z_NULL;
		inflateInit2(&zstream, 15);
	}

	zstream.next_in		= const_cast<unsigned char *>(indata);
	zstream.avail_in	= indatalen;
	zstream.next_out	= outdata;
	zstream.avail_out	= outdatalen;
	zstream.zalloc		= eqemu_alloc_func;
	zstream.zfree		= eqemu_free_func;
	zstream.opaque		= Z_NULL;

	i = inflateInit2( &zstream, 15 );
	if (i != Z_OK) {
		return 0;
	}

	zerror = inflate( &zstream, Z_FINISH );

	inflateReset(&zstream);

	if(zerror == Z_STREAM_END) {
		return zstream.total_out;
	}
	else {
		if (!iQuiet) {
			std::cout << "Error: InflatePacket: inflate() returned " << zerror << " '";
			if (zstream.msg)
				std::cout << zstream.msg;
			std::cout << "'" << std::endl;
#ifdef EQDEBUG
			DumpPacket(indata-16, indatalen+16);
#endif
		}

		if (zerror == -4 && zstream.msg == 0)
		{
			return 0;
		}

		return 0;
	}
#else
	if(indata == nullptr)
		return(0);

	z_stream zstream;
	int zerror = 0;
	int i;

	zstream.next_in		= const_cast<unsigned char *>(indata);
	zstream.avail_in	= indatalen;
	zstream.next_out	= outdata;
	zstream.avail_out	= outdatalen;
	zstream.zalloc		= eqemu_alloc_func;
	zstream.zfree		= eqemu_free_func;
	zstream.opaque		= Z_NULL;

	i = inflateInit2( &zstream, 15 );
	if (i != Z_OK) {
		return 0;
	}

	zerror = inflate( &zstream, Z_FINISH );

	if(zerror == Z_STREAM_END) {
		inflateEnd( &zstream );
		return zstream.total_out;
	}
	else {
		if (!iQuiet) {
			std::cout << "Error: InflatePacket: inflate() returned " << zerror << " '";
			if (zstream.msg)
				std::cout << zstream.msg;
			std::cout << "'" << std::endl;
#ifdef EQDEBUG
			DumpPacket(indata-16, indatalen+16);
#endif
		}

		if (zerror == -4 && zstream.msg == 0)
		{
			return 0;
		}

		zerror = inflateEnd( &zstream );
		return 0;
	}
#endif
}

uint32 roll(uint32 in, uint8 bits) {
	return ((in << bits) | (in >> (32-bits)));
}

uint64 roll(uint64 in, uint8 bits) {
	return ((in << bits) | (in >> (64-bits)));
}

uint32 rorl(uint32 in, uint8 bits) {
	return ((in >> bits) | (in << (32-bits)));
}

uint64 rorl(uint64 in, uint8 bits) {
	return ((in >> bits) | (in << (64-bits)));
}

uint32 CRCLookup(uchar idx) {
	if (idx == 0)
		return 0x00000000;

	if (idx == 1)
		return 0x77073096;

	if (idx == 2)
		return roll(CRCLookup(1), 1);

	if (idx == 4)
		return 0x076DC419;

	for (uchar b=7; b>0; b--) {
		uchar bv = 1 << b;

		if (!(idx ^ bv)) {
			// bit is only one set
			return ( roll(CRCLookup (4), b - 2) );
		}

		if (idx&bv) {
			// bit is set
			return( CRCLookup(bv) ^ CRCLookup(idx&(bv - 1)) );
		}
	}

	//Failure
	return false;
}

uint32 GenerateCRC(uint32 b, uint32 bufsize, uchar *buf) {
	uint32 CRC = (b ^ 0xFFFFFFFF);
	uint32 bufremain = bufsize;
	uchar* bufptr = buf;

	while (bufremain--) {
		CRC = CRCLookup((uchar)(*(bufptr++)^ (CRC&0xFF))) ^ (CRC >> 8);
	}

	return (htonl (CRC ^ 0xFFFFFFFF));
}