This project provides the following:
*.c— a fast base64 encoding routine based on libb64.
base64.cry— a Cryptol specification of base64.
proof/— a proof that the C code is correct with respect to the Cryptol spec.
You can read about the proof here:
To build the C code:
To run the C code:
$ echo -n 'foobar' | ./b64enc - Zm9vYmFy
C code: public domain, without any warranty. Everything else: MIT license.