Encode an arbitrary file via hexadecimal into the IDAT section of a png file
This is not quite steganography and it doesn't create a malicious payload. The intended purpose is to encode abritary files as an image so that they may be passed in messaging apps or any other service that limits by file type, so the fact the image contains a file is rather obvious. Furthermore, if sent as plaintext, patterns can be seen with the naked eye that suggest things such as language or magic numbers.
PNG was chosen because it is lossless. Metadata was not chosen because occasionally online services will strip this, destroying the file in the proccess.
The method used takes a hex dump such as from 'xxd' without newlines and chops this into 2 charactor sections which determines value of a given pixel, alternating between R, G, and B. Transparency is used to determine EOF. Sameness of input and small size can cause greater than 100% effenciency, but still a functional level is achieved for random data. ( this method is labeled 'e' for 'enhanced' ).
Due to the nature of byte encodings ( Unless I made a mistake with the code, which is entirely possible ), the chunks may not be in the same order as they were encoded. In my case, for example, AABBCC when pushed through this process outputs hex into AACCBB format. This means this enhanced method will sacrifice processing speed for data transfer file size. Luckily, once the particular format is found, it should be stable for that particular transfer, meaning that all 6 variations need not be generated every time.
Alternatively, the hex dump can be encoded into greyscale, which decreasees the size effeciency to 30-33%.
TODO
Fix Endianness problem ( finish enhanced decoder )
Finish decoder driver file
Add folders to clean up the download