Exemple #1
0
def decrypt_fp(secret_key, cipher_fp, plaintext_fp):
    key = pre_process_raw(secret_key,
                          func=key_pre_process_func)
    keys = key_schedule_s(key)[::-1]

    length = len_fp(cipher_fp)
    while True:
        block = cipher_fp.read(8)
        plaintext_block = ''.join(map(lambda x: chr(int(x, base=2)),
                                      feistel_s(pre_process_raw(block),
                                                keys)))
        if cipher_fp.tell() == length:
            plaintext_block = plaintext_block[:-ord(plaintext_block[-1])]
            plaintext_fp.write(plaintext_block)
            break

        plaintext_fp.write(plaintext_block)

    return plaintext_fp
Exemple #2
0
def encrypt_fp(secret_key, plaintext_fp, cipher_fp):
    key = pre_process_raw(secret_key,
                          func=key_pre_process_func)
    keys = key_schedule_s(key)

    length = len_fp(plaintext_fp)
    while True:
        block = plaintext_fp.read(8)
        pos = plaintext_fp.tell()
        block_len = len(block)
        if block_len < 8:
            block += padding(block_len)
            pos += 8 - block_len
        cipher_fp.write(''.join(map(lambda x: chr(int(x, base=2)),
                                    feistel_s(pre_process_raw(block),
                                              keys))))
        if pos > length:
            break

    return cipher_fp