TEA Total by Alex Holden <alex@linuxhacker.org>.
TEA Total is an extremely small private key based encryption/decryption system which uses the block variant of TEA (Tiny Encryption Algorithm) by David Wheeler and Roger Needham of the Cambridge Computer Laboratory. TEA is said to be several times faster than DES, as well as being much smaller and possibly more secure. It also isn't encumbered by any patents and the reference implementation is in the public domain. For more information about TEA, see: http://vader.brad.ac.uk/tea/tea.shtml
The latest version of this program should be available at: http://www.linuxhacker.org/tea-total/
This software is 100% public domain. See the LICENCE file for details.
To build and install the programs, see the instructions in the INSTALL file.
To learn how to use the programs, read the manual pages (they are in the doc/ directory- the *.txt files are the preprocessed versions for systems which don't have a unix manual page parser).
If you haven't done so already, you may enjoy reading test.txt.
Note that there is quite a bit of generic code here. In particular:
base64.c is a Base 64 encoder/decoder (see RFC1521). btea.c is a block TEA encoder/decoder with byte order conversion support. getarg.c is a powerful, easy to use, portable replacement for getopt(). heap.c is an efficient implementation of heap structures. huffman.c is a Huffman encoder/decoder. lineget.c is a getline() replacement which does not require the stdio library. md5.c is an implementation of the MD5 hash algorithm. randint.c includes a secure random number generator. util.c includes various utility functions.
All of this code is public domain. Feel free to copy any of it and use it in your own projects.