aespipe is a program that will take any data or file piped to it on STDIN and output symmetrically encrypted AES cypertext.
Install aespipe
Compile from source – http://loop-aes.sourceforge.net/aespipe/
Install RPM for RedHat or Centos – http://loop-aes.sourceforge.net/aespipe/
rpm -ivh http://packages.sw.be/aespipe/aespipe-2.3d-1.el5.rf.i386.rpm
Examples
Encrypt the contents of clear.txt using aes256 and output it to ciphered.txt.enc.
aespipe -e aes256 < clear.txt > ciphered.txt.enc
Decrypt the same file
aespipe -d -e aes256 < ciphered.txt.enc > unencrypted.txt
Note: passwords must be min 20 characters long.