libb64 is a library of ANSI C routines for fast encoding/decoding data 
into and from a base64-encoded format. 
C++ wrappers are included, as well as the source code for 
standalone encoding and decoding executables.

Base64 uses a subset of displayable ASCII characters, and is 
therefore a useful encoding for storing binary data in a text file,
such as XML, or sending binary data over text-only email. 

WWW: http://libb64.sourceforge.net