write-ups-challenges-2024-2025/arno/writeup.py
2024-11-25 22:26:24 +01:00

23 lines
588 B
Python

import wave
wav = wave.open("lesfilLeSduBorddemer.wav", mode='rb')
frames = wav.getnframes()
bytes = bytearray(list(wav.readframes(frames)))
# Replace each frame_byte with only the value of the LSB
for i in range(len(bytes)):
bytes[i] = bytes[i] & 1 # bitmask with 00000001
# Byte array to string
result = ""
for i in range(0, len(bytes), 8):
byte_chunk = bytes[i:i+8]
int_value = int("".join(map(str, byte_chunk)), 2)
char_value = chr(int_value)
result += char_value
# Remove the trailing '#' characters
decoded = result.split("##")[0]
print(decoded)
wav.close()