HackCon2017-Steg-writeup

Standard Steg

1 2	I hacked my friend's facebook, by seeing his chrome password. I am smart, right? Anyways, he sent this image to one of his friends, idk what it is, looks like a useless logo, can you check?

def asciiToBin(ascii):
	return ''.join(str(bin(ord(byte)))[2:].zfill(8) for byte in ascii)
def hide(img, data, outName):
	header, trailer = 2*"11001100",2*"0101010100000000"
	dataBin = header+asciiToBin(data)+trailer
	pixels, mode = list(img.getdata()), img.mode
	newPixels = []
	for i in range(len(dataBin)):
		newPixel = list(pixels[i])
		newPixel[i%len(mode)] = setLSB(newPixel[i%len(mode)], dataBin[i])
		newPixels.append(tuple(newPixel))
	newData = newPixels + pixels[len(newPixels):]
	img.putdata(newData)
	img.save(outName, "PNG")
def setLSB(target, value):
	binary = str(bin(target))[2:]
	if binary[-1] != value:
		binary = binary[:-1] + value
	return int(binary, 2)