# 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',
    'header_encode',
    'header_length',
    ]


from base64 import b64encode
from binascii import b2a_base64, a2b_base64

CRLF = '\r\n'
NL = '\n'
EMPTYSTRING = ''

# See also Charset.py
MISC_LEN = 7