zhoumingchun/secure-key-exchange

Babel - Encrypted Self Destructing Messaging with Asymmetric Key Exchange Public-Private Crypto.

Babel

Key Exchange and Self-Destructing Messages with PubNub

Babel is an open source chat widget and API built with the PubNub Global Realtime Network. With Babel you can exchange 1024-bit RSA Public Keys, and send Encrypted, Self-Destructing Messages.

Live Demo

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Source Walkthrough

###Check out the annotated source.

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API Walkthrough

1. First Steps

Babel uses both PubNub and Cryptico. So first, let's include the all the necessary libraries. We can then instantiate a Babel object by calling Babel with a username string.

<script src="http://cdn.pubnub.com/pubnub.min.js"></script>

<!-- Download both from https://github.com/lw7360/babel -->
<script src="./cryptico.js"></script> 
<script src="./babel.js"></script>

<script> 
    var doge = new Babel('doge'); // Initialize Babel with a username
</script>

2. Public Key Exchange

listUsers() returns an object with all currently connected users' usernames and their public keys.

console.log(doge.listUsers());
// {username: publicKey}
// {doge: "olpbSlUEca0VVVqcs9ciUZyP...NNIkqx9lVtUZDYLUWhnjaNrEK4E="}

myKey() returns your Cryptico RSA key.

3. Encrypted Self-Destructing Messages

sendMessage(recipient, message, ttl) encrypts message with recipient's public key, and sends the encrypted message to recipient. The message will be accessible through the returnMessages method for both you and the recipient for ttl seconds.

doge.sendMessage('shibe', 'Very greetings shibe. Much Excited!', 5);
// This will send a message to 'shibe', with the message 
// 'Very greetings shibe. Much Excited!'. 
// Both you and `shibe` will only be able to view this message for 5 seconds.

returnMessages() returns all the messages you've sent or received that have yet to time out.

console.log(doge.returnMessages());
// {
//   shibe: [
//	   {
//       TTL: 5,
//       msgID: "2fa4abf3-08d4-4e40-873f-f35540590d04",
//       plaintext: "Very greetings shibe. Much Excited!",
//       recipient: "shibe",
//       sender: "doge"
//     }
//   ]
// }

onMessage(callback) let's you set a function to be called whenever you receive or send a message.

var	messageHandler = function(msg) {console.log(msg);};
doge.onMessage(messageHandler);

// 'shibe' responds to our earlier message and sends us a message of his own.
// messageHandler would be called and would print the following.
// {
//     msgID: "d8fd0f29-81cf-4c35-8aef-59b2c664628f", 
//     plaintext: "Much hello doge!  Very cannot wait.", 
//     TTL: 5, 
//     sender: "shibe", 
//     recipient: "doge"
// }
// msgID is a unique string that can be used to identify the message.

onPresence(callback) does the same thing for presence events, i.e. users joining/leaving/timing out of the channel.

quit() causes you to leave the channel. Other users will no longer be able to retrieve your public key or send messages to you.