View source for Giana’s Return ZDA

== ZDA == 
* ''' Game ''':    [[Giana’s Return]] <br> 
* ''' Format Type ''':    Archive <br> 
* ''' [http://en.wikipedia.org/wiki/Endianness Endian Order] ''': Little Endian <br>


=== Format Specifications === 

<div class="toccolours mw-collapsible" id="mw-customcollapsible-myDivision" style="width:800px; overflow:auto;">
<pre>
// Giana's Return
// ZDA file format

// little endian

// Note: Files are compressed with ZLIB and encrypted with XOR.

//header
4 bytes (char) - magic // "ZDA\x00"
4 bytes (uint32) - number of files
4 bytes (uint32) - data start offset

num_of_files *
{
   40 bytes (char) - filename + padding
   4 bytes (uint32) - uncompressed size
   4 bytes (uint32) - compressed size
   4 bytes (uint32) - relative file offset
}

num_of_files *
{
   x bytes - file data  
}
</pre>
</div>

=== MultiEx BMS Script === 

Not written yet.

=== Notes and Comments === 

* Files inside those archives are compressed with ZLIB and encrypted with custom XOR encryption.
* Key used for encrypting file is original file with \xBB byte added at the beginning.

=== Decryption method === 
Implementation for decryption method written in Python:
<pre>
def decrypt_data(in_data):
    xor_res = b'\xBB'
    data_size = len(in_data)
    out_data = bytearray()
    
    for curr_offset in range(data_size):
        data_byte = struct.pack("B", in_data[curr_offset])
        xor_res = xore(xor_res, data_byte)
        out_data.extend(xor_res)
    
    return out_data
</pre>

=== Compatible Programs === 

* [https://github.com/bartlomiejduda/Tools/blob/master/NEW%20Tools/Gianas%20Return/Gianas_Return_ZDA_Tool.py Giana's Return ZDA Tool]
* [https://github.com/zigaudrey/ZDA-Reconstruction-Script ZDA-Reconstruction-Script]
* [https://www.dropbox.com/s/le8bnknzxke63wn/unZDA.py?dl=0 unZDA.py]
<br/><br>


[[Category:Complete Complete|Giana’s Return ZDA]]
[[Category:Platform PC|Giana’s Return ZDA]]
[[Category:CE Compressed|Giana’s Return ZDA]]
[[Category:Format_Archive | Type: Archive]]
[[Category:Extension_zda | Extension: zda]]
[[Category:BMS_None | BMS: None]]
[[Category:ZLIB compression]]
[[Category:XOR encryption]]
[[Category:File Format]]