1# Copyright (C) 2001-2006 Python Software Foundation 2# Author: Barry Warsaw 3# Contact: email-sig@python.org 4 5"""Encodings and related functions.""" 6 7__all__ = [ 8 'encode_7or8bit', 9 'encode_base64', 10 'encode_noop', 11 'encode_quopri', 12 ] 13 14 15from base64 import encodebytes as _bencode 16from quopri import encodestring as _encodestring 17 18 19 20def _qencode(s): 21 enc = _encodestring(s, quotetabs=True) 22 # Must encode spaces, which quopri.encodestring() doesn't do 23 return enc.replace(b' ', b'=20') 24 25 26def encode_base64(msg): 27 """Encode the message's payload in Base64. 28 29 Also, add an appropriate Content-Transfer-Encoding header. 30 """ 31 orig = msg.get_payload(decode=True) 32 encdata = str(_bencode(orig), 'ascii') 33 msg.set_payload(encdata) 34 msg['Content-Transfer-Encoding'] = 'base64' 35 36 37 38def encode_quopri(msg): 39 """Encode the message's payload in quoted-printable. 40 41 Also, add an appropriate Content-Transfer-Encoding header. 42 """ 43 orig = msg.get_payload(decode=True) 44 encdata = _qencode(orig) 45 msg.set_payload(encdata) 46 msg['Content-Transfer-Encoding'] = 'quoted-printable' 47 48 49 50def encode_7or8bit(msg): 51 """Set the Content-Transfer-Encoding header to 7bit or 8bit.""" 52 orig = msg.get_payload(decode=True) 53 if orig is None: 54 # There's no payload. For backwards compatibility we use 7bit 55 msg['Content-Transfer-Encoding'] = '7bit' 56 return 57 # We play a trick to make this go fast. If decoding from ASCII succeeds, 58 # we know the data must be 7bit, otherwise treat it as 8bit. 59 try: 60 orig.decode('ascii') 61 except UnicodeError: 62 msg['Content-Transfer-Encoding'] = '8bit' 63 else: 64 msg['Content-Transfer-Encoding'] = '7bit' 65 66 67 68def encode_noop(msg): 69 """Do nothing.""" 70