Bitstrings converter

README.md

Bitstrings converter

Probably many people have written something like this, for converting those joke images purporting to contain L3E7 h4xx0R c0deZ.

Data examples:

• ascii-bits.txt: taken from a random pic of a mini typewriter with a 1 and 0 keyboard.
• message.txt: taken from a music video ad with an AI-type character

Script:

• Takes a text file with typed 1 and 0 characters to represent bits.
• Strips all whitespace
• Converts them to 8-bit bytes, and prints the results.
• Two types of padding are done in case the number of bits is not a multiple of 8.
• Optionally specify an encoding to use for string printing.

A naive, dirty implementation whacked together in a few minutes.

python3 convert-bitstring.py ascii-bits.txt [ENCODING]

ascii-bits.txt

1001010101
0110001010
1100111000
1001100111
0111000110
1110101010
0011011000
1111010011
01001

convert-bitstring.py

import sys
import re


def getbyte(oz, rfill=False):
    if len(oz) != 8:
        if rfill:
            oz = oz.zfill(8)
        else:
            oz = oz.ljust(8, '0')
        print(f"Final byte: {oz}")
    return int(oz, 2)

def fillprint(direction, oz_chunks):
    left = direction == "left"
    fillname = "Big endian" if left else "Little endian"
    fillname += " padding on final byte"
    print(f"\n{fillname}:")

    mybytes = []
    for oz in oz_chunks:
        mybytes.append(getbyte(oz, left))

    decode = None if len(sys.argv) < 3 else sys.argv[2]

    if decode:
        print(str(bytes(mybytes), decode) )
    else:
        print(str(bytes(mybytes) ))

def main():
    lines = None

    with open(sys.argv[1]) as fh:
        lines = fh.readlines()

    lines = [re.sub(r'\s', '', theline) for theline in lines]
    onezeroes = ''.join(lines)

    print("%i : %s" % (len(onezeroes), onezeroes) )

    chunks, chunksize = len(onezeroes), 8

    oz_chunks = [ onezeroes[i:i+chunksize] for i in range(0, chunks, chunksize) ]

    fillprint("right", oz_chunks)
    fillprint("left", oz_chunks)

if __name__ == "__main__":
    main()

message.txt

01010100 01100101 01101100 01101100 00100000 01101101 01100101 00100000 01101000 01101111 01110111 00100000 01111001 01101111 01110101 00100000 01100110 01100101 01100101 01101100

Output for ascii-bits.txt:

85 : 1001010101011000101011001110001001100111011100011011101010100011011000111101001101001

Little endian padding on final byte:
Final byte: 01001000
b'\x95X\xac\xe2gq\xba\xa3c\xd3H'

Big endian padding on final byte:
Final byte: 00001001
b'\x95X\xac\xe2gq\xba\xa3c\xd3\t'

Output for message.txt:

160 : 0101010001100101011011000110110000100000011011010110010100100000011010000110111101110111001000000111100101101111011101010010000001100110011001010110010101101100

Little endian padding on final byte:
b'Tell me how you feel'

Big endian padding on final byte:
b'Tell me how you feel'