from collections import namedtuple
from morphys import ensure_bytes
from .converters import BaseStringConverter, Base16StringConverter, IdentityConverter, Base64StringConverter, \
Base32StringConverter
Encoding = namedtuple('Encoding', 'encoding,code,converter')
CODE_LENGTH = 1
ENCODINGS = [
Encoding('identity', b'\x00', IdentityConverter()),
Encoding('base2', b'0', BaseStringConverter('01')),
Encoding('base8', b'7', BaseStringConverter('01234567')),
Encoding('base10', b'9', BaseStringConverter('0123456789')),
Encoding('base16', b'f', Base16StringConverter()),
Encoding('base32hex', b'v', Base32StringConverter('0123456789abcdefghijklmnopqrstuv')),
Encoding('base32', b'b', Base32StringConverter('abcdefghijklmnopqrstuvwxyz234567')),
Encoding('base32z', b'h', BaseStringConverter('ybndrfg8ejkmcpqxot1uwisza345h769')),
Encoding('base58flickr', b'Z', BaseStringConverter('123456789abcdefghijkmnopqrstuvwxyzABCDEFGHJKLMNPQRSTUVWXYZ')),
Encoding('base58btc', b'z', BaseStringConverter('123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz')),
Encoding('base64', b'm', Base64StringConverter('ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/')),
Encoding('base64url', b'u',
Base64StringConverter('ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_'),
),
]
ENCODINGS_LOOKUP = {}
for codec in ENCODINGS:
ENCODINGS_LOOKUP[codec.encoding] = codec
ENCODINGS_LOOKUP[codec.code] = codec
[docs]def encode(encoding, data):
"""
Encodes the given data using the encoding that is specified
:param str encoding: encoding to use, should be one of the supported encoding
:param data: data to encode
:type data: str or bytes
:return: multibase encoded data
:rtype: bytes
:raises ValueError: if the encoding is not supported
"""
data = ensure_bytes(data, 'utf8')
try:
return ENCODINGS_LOOKUP[encoding].code + ENCODINGS_LOOKUP[encoding].converter.encode(data)
except KeyError:
raise ValueError('Encoding {} not supported.'.format(encoding))
[docs]def get_codec(data):
"""
Returns the codec used to encode the given data
:param data: multibase encoded data
:type data: str or bytes
:return: the :py:obj:`multibase.Encoding` object for the data's codec
:raises ValueError: if the codec is not supported
"""
try:
key = ensure_bytes(data[:CODE_LENGTH], 'utf8')
codec = ENCODINGS_LOOKUP[key]
except KeyError:
raise ValueError('Can not determine encoding for {}'.format(data))
else:
return codec
[docs]def is_encoded(data):
"""
Checks if the given data is encoded or not
:param data: multibase encoded data
:type data: str or bytes
:return: if the data is encoded or not
:rtype: bool
"""
try:
get_codec(data)
return True
except ValueError:
return False
[docs]def decode(data):
"""
Decode the multibase decoded data
:param data: multibase encoded data
:type data: str or bytes
:return: decoded data
:rtype: str
:raises ValueError: if the data is not multibase encoded
"""
data = ensure_bytes(data, 'utf8')
codec = get_codec(data)
return codec.converter.decode(data[CODE_LENGTH:])
