sick

sick
====

Sign and check files using ed25519.
sick(1) will let you generate private/public key pairs, sign files using your
private key, and check a file signature using public keys stored in a keyring.

Generating keys
---------------

To generate a key pair, run

	$ sick -g alice

This will create two files: `alice.key` (private) and `alice.pub` (public).
The private key is used to sign files, while the public key can be distributed
and used to check signatures.

Signing streams
---------------

Once the private key is generated, you can use it to sign streams of data with
the following command:

	$ sick -f alice.key -s < README > SIGNED

The whole stream will be dumped to stdout, and the signature will be appended.

Checking streams
----------------

### Using a file

A signed stream can be verified against a public key with the following
command:

	$ sick -f alice.pub < SIGNED

If the signature can be verified against the public key provided, the content
of the message will be dumped to stdout.

### Using a keyring

In case the `-f` flag is omited, sick(1) will check the signature against all
the files located in the $KEYRING directory.

	$ export KEYRING="$HOME/.keyring"
	$ mkdir $KEYRING
	$ mv alice.pub $KEYRING/
	$ sick < SIGNED

Trim a signature
----------------

You can discard a signature on a stream by using the `-t` (trim) flag. It will
dump the input stream to stdout without the signature:

	$ sick -t SIGNED > UNSIGNED