IceCTF Matrix writeup

matrix2qr.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-

import Image
import numpy as np

def hex2bin(hexmat):
    binmattemp = [bin(m)[2:] for m in hexmat]
    rowlen = max([len(m) for m in binmattemp])
    binmat = [[0]+[int(b) for b in row.zfill(rowlen)] for row in binmattemp]

    print rowlen+1, 'x', len(binmat)
    for i in xrange(len(binmat)):
        print ''.join([str(b) for b in binmat[i]])

    return binmat, rowlen+1, len(binmat)

def rm_col(binmat, col):
    return [row[:col]+row[col+1:] for row in binmat]


def make_bw_img(binmat, w, h, outfilename, blackbit=0):

    bwmat = [[0 if b==blackbit else 255 for b in row] for row in binmat]

    imagesize = (w, h)
    img = Image.fromarray(np.uint8(np.array(bwmat)))
    img.save(outfilename)

if __name__ == '__main__':
    hexmat = [0x00000000,
              0xff71fefe,
              0x83480082,
              0xbb4140ba,
              0xbb6848ba,
              0xbb4a80ba,
              0x83213082,
              # 0xff5556fe,
              0xff5556fe,
              0x00582e00,
              0x576fb9be,
              0x707ef09e,
              0xe74b41d6,
              0xa82c0f16,
              0x27a15690,
              0x8c643628,
              0xbfcbf976,
              0x4cd959aa,
              0x2f43d73a,
              0x5462300a,
              0x57290106,
              0xb02ace5a,
              # 0xef53f7fc,
              0xef53f7fc,
              0x00402e36,
              0xff01b6a8,
              0x83657e3a,
              0xbb3b27fa,
              0xbb5eaeac,
              0xbb1017a0,
              0x8362672c,
              0xff02a650,
              0x00000000]

    binmat, w, h = hex2bin(hexmat)
    binmat = rm_col(binmat, 22)
    binmat = rm_col(binmat, 7)
    make_bw_img(binmat, w, h, 'matrix_rmcol.png', blackbit=1)