Decrypts an ciphertext with a 1-byte XOR scheme (brute force approach)

brute_force_xor_ascii.py

"""
    TASK:
    Decrypt a piece of ciphertext which uses a 1-byte XOR Scheme.
    Brute force approach.
"""

# The flag in this one contains the word "Congratulations!"
ciphertext = "W{zsfu`axu`}{zg54@|}g4}g4`|q4rxus.4wg&%$#o#%vwp&pu&'p&\"!r$%!$!&r $ur\",!!u$i:"

def decrypt(input_str):
    KEY_SPACE = 128

    # search through key space
    for i in range(KEY_SPACE - 1):
        candidate_plaintext = ""

        # XOR-ing each char with the candidate key
        for c in list(input_str):
            XOR_value = ord(c) ^ i
            candidate_plaintext += chr(XOR_value)

        # Printing it all out on console with a line separator!
        print(candidate_plaintext)
        print("---------------------------------------------------")

decrypt(ciphertext)