fernet-cli

Now, the power of Fernet is available from the shell!

tmaher@og-kush:~$ gem install fernet-cli
Fetching: fernet-cli-0.4.gem (100%)
Successfully installed fernet-cli-0.4
Parsing documentation for fernet-cli-0.4
Installing ri documentation for fernet-cli-0.4
Done installing documentation for fernet-cli after 0 seconds
1 gem installed
tmaher@og-kush:~$ fernet-encrypt --help
Usage: fernet-encrypt [-p | -k <keyfile>] -i <infile> -o <outfile>
    -p, --prompt                     Prompt for keys
    -k, --keyfile KEYFILE
    -i, --infile INPUTFILE
    -o, --outfile OUTPUTFILE

And there's a corresponding fernet-decrypt too. The key should be a base64-encoded blob of 256-bits. If you'd rather not write it out to a file or get promted for it, you can save it to shell environment variable FERNET_CLI_KEY.

For fernet-encrypt, the infile is plaintext and the outfile is ciphertext. For fernet-decrypt, the infile is ciphertext and the outfile is plaintext.

For more information, see https://github.com/fernet/spec

These helpers support the convention of specifying - for a filename to mean stdin/stdout. However, the Ruby implementation of Fernet currently has to read the complete message into memory before encrypting/decrypting. If you're planning on using this in any vaguely complicated shell pipeline, your computer's memory usage will assplode.