zip archive reader

main.cpp

#include <windows.h>
#include <stdio.h>
#include <string>
#include <map>

	#pragma pack(1)
	struct package_file
	{
		unsigned int   signature;
		unsigned short version;
		unsigned short flags;
		unsigned short compression;
		unsigned short lastmodified_time;
		unsigned short lastmodified_date;
		unsigned int   crc32;
		unsigned int   compressed_size;
		unsigned int   uncompressed_size;
		unsigned short filename_length;
		unsigned short extra_length;
	};

	#pragma pack(1)
	struct package_cd_file
	{
		unsigned int   signature;
		unsigned short versionCreated;
		unsigned short version;
		unsigned short flags;
		unsigned short compression;
		unsigned short lastmodified_time;
		unsigned short lastmodified_date;
		unsigned int   crc32;
		unsigned int   compressed_size;
		unsigned int   uncompressed_size;
		unsigned short filename_length;
		unsigned short extra_length;
		unsigned short filecomment_length;
		unsigned short disk;
		unsigned short internal_attributes;
		unsigned int   external_attributes;
		unsigned int   offset;
	};

	#pragma pack(1)
	struct package_cd_end
	{
		unsigned int   signature;
		unsigned short disk_end;
		unsigned short disk_start;
		unsigned short number_disk;
		unsigned short number_total;
		unsigned int   size;
		unsigned int   offset;
		unsigned short comment_length;
	};

	struct packaged_entry
	{
		unsigned int   signature;
		unsigned short versionCreated;
		unsigned short version;
		unsigned short flags;
		unsigned short compression;
		unsigned short lastmodified_time;
		unsigned short lastmodified_date;
		unsigned int   crc32;
		unsigned int   compressed_size;
		unsigned int   uncompressed_size;
		unsigned short filename_length;
		unsigned short extra_length;
		unsigned short filecomment_length;
		unsigned short disk;
		unsigned short internal_attributes;
		unsigned int   external_attributes;
		unsigned int   offset;

	public:
		packaged_entry()
		{
		}

		packaged_entry(const package_cd_file& cd)
		{
			signature=cd.signature;
			versionCreated=cd.versionCreated;
			version=cd.version;
			flags=cd.flags;
			compression=cd.compression;
			lastmodified_time=cd.lastmodified_time;
			lastmodified_date=cd.lastmodified_date;
			crc32=cd.crc32;
			compressed_size=cd.compressed_size;
			uncompressed_size=cd.uncompressed_size;
			filename_length=cd.filename_length;
			extra_length=cd.extra_length;
			filecomment_length=cd.filecomment_length;
			disk=cd.disk;
			internal_attributes=cd.internal_attributes;
			external_attributes=cd.external_attributes;
			offset=cd.offset;
		}

		packaged_entry& operator=(const packaged_entry& cd)
		{
			signature=cd.signature;
			versionCreated=cd.versionCreated;
			version=cd.version;
			flags=cd.flags;
			compression=cd.compression;
			lastmodified_time=cd.lastmodified_time;
			lastmodified_date=cd.lastmodified_date;
			crc32=cd.crc32;
			compressed_size=cd.compressed_size;
			uncompressed_size=cd.uncompressed_size;
			filename_length=cd.filename_length;
			extra_length=cd.extra_length;
			filecomment_length=cd.filecomment_length;
			disk=cd.disk;
			internal_attributes=cd.internal_attributes;
			external_attributes=cd.external_attributes;
			offset=cd.offset;	
			return *this;
		}
		
	};

std::map<std::string, packaged_entry> m_filetable;

void main()
{
	HANDLE hZipArchive; 
	DWORD hZipArchiveLength;
	hZipArchive = CreateFileA("E:\\Workspaces\\dds.zip", GENERIC_READ, FILE_SHARE_READ, 0, OPEN_EXISTING,0, 0);	
	hZipArchiveLength = ::GetFileSize(hZipArchive, 0);
	if( hZipArchiveLength < 4 ) {
		__asm int 3;
	} else {
		DWORD buffer = 0;
		DWORD bytesRead = 0;
		
		for( int i = 4; i < hZipArchiveLength; i++ ) {
			DWORD retval = ::SetFilePointer(hZipArchive, -i, 0, FILE_END);
			if( retval == INVALID_SET_FILE_POINTER || retval != (hZipArchiveLength - i)) 
			{
				__asm int 3;
				printf("test");
			}

			package_cd_end eocd;
			::ReadFile(hZipArchive, &buffer, 4, &bytesRead, 0);	
			if( bytesRead == 4 && buffer == 0x06054b50 ) {
			
				DWORD retval = ::SetFilePointer(hZipArchive, -i, 0, FILE_END);
				::ReadFile(hZipArchive, &eocd, sizeof(eocd), &bytesRead, 0);	
				retval = ::SetFilePointer(hZipArchive, eocd.offset, 0, FILE_BEGIN);
				if( retval == INVALID_SET_FILE_POINTER || retval != eocd.offset) {
					__asm int 3;
				}
				
				while(retval < (hZipArchiveLength - i) )
				{
					package_cd_file cd;
					::ReadFile(hZipArchive, &cd, sizeof(package_cd_file), &bytesRead, 0);
					if( cd.signature != 0x02014b50 ) 
						__asm int 3;

					std::string filename; filename.resize(cd.filename_length);
					::ReadFile(hZipArchive, const_cast<char*>(filename.c_str()), cd.filename_length, &bytesRead, 0);
					retval = ::SetFilePointer(hZipArchive, cd.extra_length + cd.filecomment_length, 0, FILE_CURRENT);
					m_filetable[filename] = packaged_entry(cd);
					printf("%s\r\n", filename.c_str());
				}

				break;
			}
		}

		getchar();
	}
}