# Simple AES-256-CCM-PSK drop in front end script for the sjcl library

This script is intended to be just included in any HTML document via a simple
`<script src="sjcl-front.js"></script>` and provide ad-hoc group crypto for that
site.

The script walks through all text nodes and checks for the sjcl-front signature
sjcl:// and tries to retrieve a key from localStorage or sessionStorage whose
name matches the one encoded as associated data in the encoded sjcl dictionary.
If it can decrypt the string, the text node's content is replaced by the
plaintext and a class sjcl-decrypted is added to its parent node.

If the respective key can not be found, the class sjcl-undecrypted is added to
the parent node, which also receives a copy of the ciphertext, before the text
node is replaced by an informative message. A click handler for sjcl-undecrypted
objects allows to later re-decrypt the text by providing a key.

During initialisation, the script also walks through all TEXTAREA nodes and
injects a hook revealing a contextual drop down menu that allows encrypting the
TEXTAREA's content, decrypting it and adding/deleting keys in localStorage.
Future versions may allow adding that hook to text input fields or filtering by
class or id.

Finally the script injects CSS to the document's head to get the injected nodes
working.

You can try the script at https://erdgeist.org/webcrypto/.

The library that does the heavy lifting can be found here:
https://github.com/bitwiseshiftleft/sjcl