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Diffstat (limited to 'Lib/email/base64mime.py')
| -rw-r--r-- | Lib/email/base64mime.py | 184 |
1 files changed, 0 insertions, 184 deletions
diff --git a/Lib/email/base64mime.py b/Lib/email/base64mime.py deleted file mode 100644 index 0b29eb8..0000000 --- a/Lib/email/base64mime.py +++ /dev/null @@ -1,184 +0,0 @@ -# Copyright (C) 2002-2006 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__ = [ - 'base64_len', - 'body_decode', - 'body_encode', - 'decode', - 'decodestring', - 'encode', - 'encodestring', - 'header_encode', - ] - -import re - -from binascii import b2a_base64, a2b_base64 -from email.utils import fix_eols - -CRLF = '\r\n' -NL = '\n' -EMPTYSTRING = '' - -# See also Charset.py -MISC_LEN = 7 - - - -# Helpers -def base64_len(s): - """Return the length of s when it is encoded with base64.""" - groups_of_3, leftover = divmod(len(s), 3) - # 4 bytes out for each 3 bytes (or nonzero fraction thereof) in. - # Thanks, Tim! - n = groups_of_3 * 4 - if leftover: - n += 4 - return n - - - -def header_encode(header, charset='iso-8859-1', keep_eols=False, - maxlinelen=76, eol=NL): - """Encode a single header line with Base64 encoding in a given charset. - - Defined in RFC 2045, this Base64 encoding is identical to normal Base64 - encoding, except that each line must be intelligently wrapped (respecting - the Base64 encoding), and subsequent lines must start with a space. - - charset names the character set to use to encode the header. It defaults - to iso-8859-1. - - End-of-line characters (\\r, \\n, \\r\\n) will be automatically converted - to the canonical email line separator \\r\\n unless the keep_eols - parameter is True (the default is False). - - Each line of the header will be terminated in the value of eol, which - defaults to "\\n". Set this to "\\r\\n" if you are using the result of - this function directly in email. - - The resulting string will be in the form: - - "=?charset?b?WW/5ciBtYXp66XLrIHf8eiBhIGhhbXBzdGHuciBBIFlv+XIgbWF6euly?=\\n - =?charset?b?6yB3/HogYSBoYW1wc3Rh7nIgQkMgWW/5ciBtYXp66XLrIHf8eiBhIGhh?=" - - with each line wrapped at, at most, maxlinelen characters (defaults to 76 - characters). - """ - # Return empty headers unchanged - if not header: - return header - - if not keep_eols: - header = fix_eols(header) - - # Base64 encode each line, in encoded chunks no greater than maxlinelen in - # length, after the RFC chrome is added in. - base64ed = [] - max_encoded = maxlinelen - len(charset) - MISC_LEN - max_unencoded = max_encoded * 3 // 4 - - for i in range(0, len(header), max_unencoded): - base64ed.append(b2a_base64(header[i:i+max_unencoded])) - - # Now add the RFC chrome to each encoded chunk - lines = [] - for line in base64ed: - # Ignore the last character of each line if it is a newline - if line.endswith(NL): - line = line[:-1] - # Add the chrome - lines.append('=?%s?b?%s?=' % (charset, line)) - # Glue the lines together and return it. BAW: should we be able to - # specify the leading whitespace in the joiner? - joiner = eol + ' ' - return joiner.join(lines) - - - -def encode(s, binary=True, maxlinelen=76, eol=NL): - """Encode a string with base64. - - Each line will be wrapped at, at most, maxlinelen characters (defaults to - 76 characters). - - If binary is False, end-of-line characters will be converted to the - canonical email end-of-line sequence \\r\\n. Otherwise they will be left - verbatim (this is the default). - - 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 - - if not binary: - s = fix_eols(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 = 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) - - -# For convenience and backwards compatibility w/ standard base64 module -body_encode = encode -encodestring = encode - - - -def decode(s, convert_eols=None): - """Decode a raw base64 string. - - If convert_eols is set to a string value, all canonical email linefeeds, - e.g. "\\r\\n", in the decoded text will be converted to the value of - convert_eols. os.linesep is a good choice for convert_eols if you are - decoding a text attachment. - - 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 s: - return s - - dec = a2b_base64(s) - if convert_eols: - return dec.replace(CRLF, convert_eols) - return dec - - -# For convenience and backwards compatibility w/ standard base64 module -body_decode = decode -decodestring = decode |