0  0$ lad*j"Tځz@ؔţ 6? #! /usr/bin/python3.9 """Base16, Base32, Base64 (RFC 3548), Base85 and Ascii85 data encodings""" # Modified 04-Oct-1995 by Jack Jansen to use binascii module # Modified 30-Dec-2003 by Barry Warsaw to add full RFC 3548 support # Modified 22-May-2007 by Guido van Rossum to use bytes everywhere import re import struct import binascii __all__ = [ # Legacy interface exports traditional RFC 2045 Base64 encodings 'encode', 'decode', 'encodebytes', 'decodebytes', # Generalized interface for other encodings 'b64encode', 'b64decode', 'b32encode', 'b32decode', 'b16encode', 'b16decode', # Base85 and Ascii85 encodings 'b85encode', 'b85decode', 'a85encode', 'a85decode', # Standard Base64 encoding 'standard_b64encode', 'standard_b64decode', # Some common Base64 alternatives. As referenced by RFC 3458, see thread # starting at: # # http://zgp.org/pipermail/p2p-hackers/2001-September/000316.html 'urlsafe_b64encode', 'urlsafe_b64decode', ] bytes_types = (bytes, bytearray) # Types acceptable as binary data def _bytes_from_decode_data(s): if isinstance(s, str): try: return s.encode('ascii') except UnicodeEncodeError: raise ValueError('string argument should contain only ASCII characters') if isinstance(s, bytes_types): return s try: return memoryview(s).tobytes() except TypeError: raise TypeError("argument should be a bytes-like object or ASCII " "string, not %r" % s.__class__.__name__) from None # Base64 encoding/decoding uses binascii def b64encode(s, altchars=None): """Encode the bytes-like object s using Base64 and return a bytes object. Optional altchars should be a byte string of length 2 which specifies an alternative alphabet for the '+' and '/' characters. This allows an application to e.g. generate url or filesystem safe Base64 strings. """ encoded = binascii.b2a_base64(s, newline=False) if altchars is not None: assert len(altchars) == 2, repr(altchars) return encoded.translate(bytes.maketrans(b'+/', altchars)) return encoded def b64decode(s, altchars=None, validate=False): """Decode the Base64 encoded bytes-like object or ASCII string s. Optional altchars must be a bytes-like object or ASCII string of length 2 which specifies the alternative alphabet used instead of the '+' and '/' characters. The result is returned as a bytes object. A binascii.Error is raised if s is incorrectly padded. If validate is False (the default), characters that are neither in the normal base-64 alphabet nor the alternative alphabet are discarded prior to the padding check. If validate is True, these non-alphabet characters in the input result in a binascii.Error. """ s = _bytes_from_decode_data(s) if altchars is not None: altchars = _bytes_from_decode_data(altchars) assert len(altchars) == 2, repr(altchars) s = s.translate(bytes.maketrans(altchars, b'+/')) if validate and not re.fullmatch(b'[A-Za-z0-9+/]*={0,2}', s): raise binascii.Error('Non-base64 digit found') return binascii.a2b_base64(s) def standard_b64encode(s): """Encode bytes-like object s using the standard Base64 alphabet. The result is returned as a bytes object. """ return b64encode(s) def standard_b64decode(s): """Decode bytes encoded with the standard Base64 alphabet. Argument s is a bytes-like object or ASCII string to decode. The result is returned as a bytes object. A binascii.Error is raised if the input is incorrectly padded. Characters that are not in the standard alphabet are discarded prior to the padding check. """ return b64decode(s) _urlsafe_encode_translation = bytes.maketrans(b'+/', b'-_') _urlsafe_decode_translation = bytes.maketrans(b'-_', b'+/') def urlsafe_b64encode(s): """Encode bytes using the URL- and filesystem-saf