libb64

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.

C 语言实现：
https://sourceforge.net/projects/libb64/

C++语言实现：
https://sourceforge.net/projects/base64encdec/
https://sourceforge.net/projects/libbase64cpp/