""" Base32 encoding and decoding https://en.wikipedia.org/wiki/Base32 """ B32_CHARSET = "ABCDEFGHIJKLMNOPQRSTUVWXYZ234567" def base32_encode(data: bytes) -> bytes: """ >>> base32_encode(b"Hello World!") b'JBSWY3DPEBLW64TMMQQQ====' >>> base32_encode(b"123456") b'GEZDGNBVGY======' >>> base32_encode(b"some long complex string") b'ONXW2ZJANRXW4ZZAMNXW24DMMV4CA43UOJUW4ZY=' """ binary_data = "".join(bin(ord(d))[2:].zfill(8) for d in data.decode("utf-8")) binary_data = binary_data.ljust(5 * ((len(binary_data) // 5) + 1), "0") b32_chunks = map("".join, zip(*[iter(binary_data)] * 5)) b32_result = "".join(B32_CHARSET[int(chunk, 2)] for chunk in b32_chunks) return bytes(b32_result.ljust(8 * ((len(b32_result) // 8) + 1), "="), "utf-8") def base32_decode(data: bytes) -> bytes: """ >>> base32_decode(b'JBSWY3DPEBLW64TMMQQQ====') b'Hello World!' >>> base32_decode(b'GEZDGNBVGY======') b'123456' >>> base32_decode(b'ONXW2ZJANRXW4ZZAMNXW24DMMV4CA43UOJUW4ZY=') b'some long complex string' """ binary_chunks = "".join( bin(B32_CHARSET.index(_d))[2:].zfill(5) for _d in data.decode("utf-8").strip("=") ) binary_data = list(map("".join, zip(*[iter(binary_chunks)] * 8))) return bytes("".join([chr(int(_d, 2)) for _d in binary_data]), "utf-8") if __name__ == "__main__": import doctest doctest.testmod()