mirror of
https://github.com/bvanroll/odiseectf.git
synced 2025-08-29 03:42:41 +00:00
51 lines
1.6 KiB
Python
51 lines
1.6 KiB
Python
import os
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import sys
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KEY_SIZE = 10
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def expand_key(key, length):
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return int(length / len(key)) * key + key[0:(length % len(key))]
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def xor(s1, s2):
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assert len(s1) == len(s2)
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return bytes([(a ^ b) for a, b in zip(s1, s2)])
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def main():
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if len(sys.argv) <= 2:
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key = os.urandom(KEY_SIZE)
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print(type(key))
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filename = sys.argv[1]
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f = open(filename,'rb')
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data = f.read()
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f.close()
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#temp = bytes([0x47, 0x49, 0x46, 0x38, 0x39, 0x61, 0xc0, 0x03, 0x80, 0x02])
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#eerste 10 bytes van voorbeeld afbeelding
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temp = bytes([0x49,0x47, 0x38, 0x46, 0x61, 0x39, 0x03, 0xc0, 0x02, 0x80])
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#en dan krijg je deze bytes list
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#solution = bytes([0x47, 0x3b, 0x57, 0x2b, 0x07, 0xd0, 0x29, 0xdb, 0x3b, 0x82])
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#dus blijkbaar was de eerste set van bytes verkerd van volgorde, dus dit is de key die we dan krijgen (met de tweede temp)
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#07a70ffe4f233ffbf9dd
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#solution = bytes([0xf7, 0xa3, 0x1b, 0x32, 0xb1, 0x56, 0x94, 0x38, 0x3c, 0x90])
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#solution = bytes.fromhex("07a70ffe4f233ffbf9dd")
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key = bytes.fromhex("0123456789")
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key = temp
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expanded_key = expand_key(key, len(data))
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data_encrypted = xor(expanded_key, data)
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print(data_encrypted)
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f = open(filename + ".enc", "wb")
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f.write(data_encrypted)
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f.close()
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print("File %s encrypted with key: %s" % (filename, key.hex()))
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else:
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print("Usage: %s <filename>" % (sys.argv[0]))
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if __name__ == "__main__":
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main()
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