aescrypt

Command-line AES encryption/decryption suite

From the aescrypt README.html: This is a program for encrypting/decrypting streams of data using Rijndael and Cipher Block Feedback mode (CFB-128). ... 5. This program was deliberately kept extremely simple. It is not intended to be a full encryption solution, it is intended to be used within scripts as part of a complete solution. Keychain management, public key signatures, etc. are all expected to be done external to this program.