Story of 1 and 2 - bugku challenge
File
In this challenge, we got a file named ‘1和0的故事.txt’, whose content is as follows:
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| 0000000001110010000000000
0000000000011110100000000
0000000001110001000000000
0000000010111100000000000
0000000010101010000000000
0000000001100010100000000
0000000010101010100000000
0000000001000001100000000
1100011101110110100011000
0001000010110010010010100
0100111101000011101110011
0011110100101011001001001
1000001001100001001101000
1111000111111011100101000
1011011111001101111110111
1000110110010010101101100
1000111100111111111110111
0000000010110001100010100
0000000010010100101010001
0000000010101010100011001
0000000000100111111110010
0000000000011001011110111
0000000001001100100100001
0000000011000011011011001
0000000011010000101110101
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Solving process
This file looks like a QR code, and the 0 and 1 easily remind us of black and white.
So we wrote python script to recover QR code.
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| import cv2
import numpy as np
with open('1和0的故事.txt', 'r') as f:
data = f.readlines()
data = [[int(m) for m in list(line)] for line in [i.split('\n')[0] for i in data]]
data = np.array(data)
width = height = 125
time = 5
img = np.zeros([width, height, 3], dtype=np.uint8)
for i in range(width//time):
for j in range(height//time):
value = 0 if data[i, j] else 1
img[i*time:i*time+time, j*time:j*time+time, :] = [value * 255, value * 255, value * 255]
cv2.imwrite("qrcode.jpg", img)
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Ran the script and we got an image like this:
but it seems like we lost the position like shown below.
source: wikipedia
There were so many methods to add on the position, like PhotoShop etc.
I chose to modify the txt file to this:
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| 1111111001110010001111111
1000001000011110101000001
1011101001110001001011101
1011101010111100001011101
1011101010101010001011101
1000001001100010101000001
1111111010101010101111111
0000000001000001100000000
1100011101110110100011000
0001000010110010010010100
0100111101000011101110011
0011110100101011001001001
1000001001100001001101000
1111000111111011100101000
1011011111001101111110111
1000110110010010101101100
1000111100111111111110111
0000000010110001100010100
1111111010010100101010001
1000001010101010100011001
1011101000100111111110010
1011101000011001011110111
1011101001001100100100001
1000001011000011011011001
1111111011010000101110101
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then we ran again and got the correct QR code.
Submit it to any QR code recognition website such as this one, and we got the flag.
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| flag{QR_c0de_1s_1nterest1n9}
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