\section{\module{base64} --- Encode and decode MIME base64 encoding.} \declaremodule{standard}{base64} \modulesynopsis{Encode and decode files using the MIME base64 encoding.} \indexii{base64}{encoding} \index{MIME!base64 encoding} This module performs base64 encoding and decoding of arbitrary binary strings into text strings that can be safely emailed or posted. The encoding scheme is defined in \rfc{1421} (``Privacy Enhancement for Internet Electronic Mail: Part I: Message Encryption and Authentication Procedures'', section 4.3.2.4, ``Step 4: Printable Encoding'') and is used for MIME email and various other Internet-related applications; it is not the same as the output produced by the \program{uuencode} program. For example, the string \code{'www.python.org'} is encoded as the string \code{'d3d3LnB5dGhvbi5vcmc=\e n'}. \begin{funcdesc}{decode}{input, output} Decode the contents of the \var{input} file and write the resulting binary data to the \var{output} file. \var{input} and \var{output} must either be file objects or objects that mimic the file object interface. \var{input} will be read until \code{\var{input}.read()} returns an empty string. \end{funcdesc} \begin{funcdesc}{decodestring}{s} Decode the string \var{s}, which must contain one or more lines of base64 encoded data, and return a string containing the resulting binary data. \end{funcdesc} \begin{funcdesc}{encode}{input, output} Encode the contents of the \var{input} file and write the resulting base64 encoded data to the \var{output} file. \var{input} and \var{output} must either be file objects or objects that mimic the file object interface. \var{input} will be read until \code{\var{input}.read()} returns an empty string. \end{funcdesc} \begin{funcdesc}{encodestring}{s} Encode the string \var{s}, which can contain arbitrary binary data, and return a string containing one or more lines of base64 encoded data. \end{funcdesc}