"""The base32 decoder implementation."""
import base64
import binascii
from dfvfs.encoding import decoder
from dfvfs.encoding import manager
from dfvfs.lib import definitions
from dfvfs.lib import errors
[docs]
class Base32Decoder(decoder.Decoder):
"""Base32 decoder using base64."""
ENCODING_METHOD = definitions.ENCODING_METHOD_BASE32
[docs]
def Decode(self, encoded_data):
"""Decode the encoded data.
Args:
encoded_data (byte): encoded data.
Returns:
tuple(bytes, bytes): decoded data and remaining encoded data.
Raises:
BackEndError: if the base32 stream cannot be decoded.
"""
try:
decoded_data = base64.b32decode(encoded_data, casefold=False)
except (TypeError, binascii.Error) as exception:
raise errors.BackEndError(
f"Unable to decode base32 stream with error: {exception!s}."
)
return decoded_data, b""
manager.EncodingManager.RegisterDecoder(Base32Decoder)