| 1 | # Copyright (C) 2001-2004 Python Software Foundation |
| 2 | # Author: Barry Warsaw |
| 3 | # Contact: email-sig@python.org |
| 4 | |
| 5 | """Encodings and related functions.""" |
| 6 | |
| 7 | import base64 |
| 8 | from quopri import encodestring as _encodestring |
| 9 | |
| 10 | def _qencode(s): |
| 11 | enc = _encodestring(s, quotetabs=True) |
| 12 | # Must encode spaces, which quopri.encodestring() doesn't do |
| 13 | return enc.replace(' ', '=20') |
| 14 | |
| 15 | |
| 16 | def _bencode(s): |
| 17 | # We can't quite use base64.encodestring() since it tacks on a "courtesy |
| 18 | # newline". Blech! |
| 19 | if not s: |
| 20 | return s |
| 21 | hasnewline = (s[-1] == '\n') |
| 22 | value = base64.encodestring(s) |
| 23 | if not hasnewline and value[-1] == '\n': |
| 24 | return value[:-1] |
| 25 | return value |
| 26 | |
| 27 | |
| 28 | \f |
| 29 | def encode_base64(msg): |
| 30 | """Encode the message's payload in Base64. |
| 31 | |
| 32 | Also, add an appropriate Content-Transfer-Encoding header. |
| 33 | """ |
| 34 | orig = msg.get_payload() |
| 35 | encdata = _bencode(orig) |
| 36 | msg.set_payload(encdata) |
| 37 | msg['Content-Transfer-Encoding'] = 'base64' |
| 38 | |
| 39 | |
| 40 | \f |
| 41 | def encode_quopri(msg): |
| 42 | """Encode the message's payload in quoted-printable. |
| 43 | |
| 44 | Also, add an appropriate Content-Transfer-Encoding header. |
| 45 | """ |
| 46 | orig = msg.get_payload() |
| 47 | encdata = _qencode(orig) |
| 48 | msg.set_payload(encdata) |
| 49 | msg['Content-Transfer-Encoding'] = 'quoted-printable' |
| 50 | |
| 51 | |
| 52 | \f |
| 53 | def encode_7or8bit(msg): |
| 54 | """Set the Content-Transfer-Encoding header to 7bit or 8bit.""" |
| 55 | orig = msg.get_payload() |
| 56 | if orig is None: |
| 57 | # There's no payload. For backwards compatibility we use 7bit |
| 58 | msg['Content-Transfer-Encoding'] = '7bit' |
| 59 | return |
| 60 | # We play a trick to make this go fast. If encoding to ASCII succeeds, we |
| 61 | # know the data must be 7bit, otherwise treat it as 8bit. |
| 62 | try: |
| 63 | orig.encode('ascii') |
| 64 | except UnicodeError: |
| 65 | # iso-2022-* is non-ASCII but still 7-bit |
| 66 | charset = msg.get_charset() |
| 67 | output_cset = charset and charset.output_charset |
| 68 | if output_cset and output_cset.lower().startswith('iso-2202-'): |
| 69 | msg['Content-Transfer-Encoding'] = '7bit' |
| 70 | else: |
| 71 | msg['Content-Transfer-Encoding'] = '8bit' |
| 72 | else: |
| 73 | msg['Content-Transfer-Encoding'] = '7bit' |
| 74 | |
| 75 | |
| 76 | \f |
| 77 | def encode_noop(msg): |
| 78 | """Do nothing.""" |