mirror of
https://github.com/python/cpython.git
synced 2025-08-08 19:09:46 +00:00
2cc1f6d95b
email.base64mime, but test_smtplib still has failures for me. They are timeout errors so think they're more related to my current wacky network setup than bugs remaining in the code related to the email package. This also r57693 that got clobbered with the sandbox sync, and fixes a couple of other minor problems that cropped up. I will kill the sandbox branch next. The email package now has 11F/11E.
121 lines
3.4 KiB
Python
121 lines
3.4 KiB
Python
# Copyright (C) 2002-2007 Python Software Foundation
|
||
# Author: Ben Gertzfield
|
||
# Contact: email-sig@python.org
|
||
|
||
"""Base64 content transfer encoding per RFCs 2045-2047.
|
||
|
||
This module handles the content transfer encoding method defined in RFC 2045
|
||
to encode arbitrary 8-bit data using the three 8-bit bytes in four 7-bit
|
||
characters encoding known as Base64.
|
||
|
||
It is used in the MIME standards for email to attach images, audio, and text
|
||
using some 8-bit character sets to messages.
|
||
|
||
This module provides an interface to encode and decode both headers and bodies
|
||
with Base64 encoding.
|
||
|
||
RFC 2045 defines a method for including character set information in an
|
||
`encoded-word' in a header. This method is commonly used for 8-bit real names
|
||
in To:, From:, Cc:, etc. fields, as well as Subject: lines.
|
||
|
||
This module does not do the line wrapping or end-of-line character conversion
|
||
necessary for proper internationalized headers; it only does dumb encoding and
|
||
decoding. To deal with the various line wrapping issues, use the email.Header
|
||
module.
|
||
"""
|
||
|
||
__all__ = [
|
||
'body_decode',
|
||
'body_encode',
|
||
'decode',
|
||
'decodestring',
|
||
'encode',
|
||
'encodestring',
|
||
'header_encode',
|
||
'header_length',
|
||
]
|
||
|
||
import re
|
||
|
||
from base64 import b64encode
|
||
from binascii import b2a_base64, a2b_base64
|
||
|
||
CRLF = '\r\n'
|
||
NL = '\n'
|
||
EMPTYSTRING = ''
|
||
|
||
# See also Charset.py
|
||
MISC_LEN = 7
|
||
|
||
|
||
|
||
# Helpers
|
||
def header_length(bytearray):
|
||
"""Return the length of s when it is encoded with base64."""
|
||
groups_of_3, leftover = divmod(len(bytearray), 3)
|
||
# 4 bytes out for each 3 bytes (or nonzero fraction thereof) in.
|
||
n = groups_of_3 * 4
|
||
if leftover:
|
||
n += 4
|
||
return n
|
||
|
||
|
||
|
||
def header_encode(header_bytes, charset='iso-8859-1'):
|
||
"""Encode a single header line with Base64 encoding in a given charset.
|
||
|
||
charset names the character set to use to encode the header. It defaults
|
||
to iso-8859-1. Base64 encoding is defined in RFC 2045.
|
||
"""
|
||
# Return empty headers unchanged
|
||
if not header_bytes:
|
||
return str(header_bytes)
|
||
encoded = b64encode(header_bytes)
|
||
return '=?%s?b?%s?=' % (charset, encoded)
|
||
|
||
|
||
|
||
def body_encode(s, maxlinelen=76, eol=NL):
|
||
"""Encode a string with base64.
|
||
|
||
Each line will be wrapped at, at most, maxlinelen characters (defaults to
|
||
76 characters).
|
||
|
||
Each line of encoded text will end with eol, which defaults to "\\n". Set
|
||
this to "\r\n" if you will be using the result of this function directly
|
||
in an email.
|
||
"""
|
||
if not s:
|
||
return s
|
||
|
||
encvec = []
|
||
max_unencoded = maxlinelen * 3 // 4
|
||
for i in range(0, len(s), max_unencoded):
|
||
# BAW: should encode() inherit b2a_base64()'s dubious behavior in
|
||
# adding a newline to the encoded string?
|
||
enc = str(b2a_base64(s[i:i + max_unencoded]))
|
||
if enc.endswith(NL) and eol != NL:
|
||
enc = enc[:-1] + eol
|
||
encvec.append(enc)
|
||
return EMPTYSTRING.join(encvec)
|
||
|
||
|
||
|
||
def decode(string):
|
||
"""Decode a raw base64 string, returning a bytes object.
|
||
|
||
This function does not parse a full MIME header value encoded with
|
||
base64 (like =?iso-8895-1?b?bmloISBuaWgh?=) -- please use the high
|
||
level email.Header class for that functionality.
|
||
"""
|
||
if not string:
|
||
return bytes()
|
||
elif isinstance(string, str):
|
||
return a2b_base64(string.encode('raw-unicode-escape'))
|
||
else:
|
||
return a2b_base64(s)
|
||
|
||
|
||
# For convenience and backwards compatibility w/ standard base64 module
|
||
body_decode = decode
|
||
decodestring = decode
|