Add a demo for group messaging via the JS bindings

1 files changed, 421 insertions, 0 deletions

diff --git a/javascript/demo/group_demo.js b/javascript/demo/group_demo.js
new file mode 100644
index 0000000..c8939d3
--- /dev/null
+++ b/javascript/demo/group_demo.js
@@ -0,0 +1,421 @@
+/* Javascript parts of the group demo. To use, load group_demo.html in your
+ * browser.
+ */
+
+function buttonAndTextElement(buttonLabel, textContent, clickHandler) {
+    var el = document.createElement("div");
+
+    var button = document.createElement("button");
+    el.appendChild(button);
+    button.appendChild(document.createTextNode(buttonLabel));
+
+    var message_element = document.createElement("tt");
+    el.appendChild(message_element);
+
+    var content = document.createTextNode(textContent);
+    message_element.appendChild(content);
+
+    el.addEventListener("click", clickHandler, false);
+    return el;
+}
+
+function DemoUser(name) {
+    this.name = name;
+    this.olmAccount = new Olm.Account();
+    this.olmAccount.create();
+
+    /* a list of the people in our chat */
+    this.peers = [];
+
+    /* for each peer, a one-to-one session - indexed by id key and created on
+     * demand */
+    this.peerSessions = {}
+
+    /* for each peer, info on their sender session - indexed by id key and
+     * session id */
+    this.peerGroupSessions = {};
+
+    /* our outbound group session */
+    this.groupSession = undefined;
+
+    /* a list of pending tasks */
+    this.tasks = [];
+    this.taskWorker = undefined;
+}
+
+DemoUser.prototype._progress = function(message) {
+    var progress = this.progressElement;
+
+    var message_element = document.createElement("pre");
+    var start_content = document.createTextNode(message + "...");
+    function start() {
+        message_element.appendChild(start_content);
+        progress.appendChild(message_element);
+    }
+    function done(res) {
+        var done_content = document.createTextNode(message + "..." + res);
+        message_element.replaceChild(done_content, start_content);
+    }
+    return {start:start, done:done};
+};
+
+DemoUser.prototype._do_tasks = function() {
+    var self = this;
+    var task = self.tasks.shift();
+    var desc = task[0];
+    var func = task[1];
+    var callback = task[2];
+
+    var p = self._progress(desc);
+    p.start();
+
+    function done() {
+        p.done("Done");
+
+        if (callback) {
+            try {
+                callback.apply(undefined, arguments)
+            } catch (e) {
+                console.error("Uncaught exception in callback", e.stack || e);
+            }
+        }
+
+        start_tasks();
+    }
+
+    // sleep 50ms before actually doing the task
+    self.taskWorker = window.setTimeout(function() {
+        try {
+            task[1](done);
+        } catch (e) {
+            console.error("Uncaught exception in task", e.stack || e);
+            p.done("Failed: "+e);
+            start_tasks();
+        }
+    }, 50);
+
+
+    function start_tasks() {
+        if (self.tasks.length == 0) {
+            self.taskWorker = undefined;
+            return;
+        }
+
+        self.taskWorker = window.setTimeout(self._do_tasks.bind(self), 50);
+    }
+}
+
+/**
+ * add a function "task" to this user's queue of things to do.
+ *
+ * task is called with a single argument 'done' which is a function to call
+ * once the task is complete.
+ *
+ * 'callback' is called once the task is complete, with any arguments that
+ * were passed to 'done'.
+ */
+DemoUser.prototype.addTask = function(description, task, callback) {
+    this.tasks.push([description, task, callback]);
+    if(!this.taskWorker) {
+        this._do_tasks();
+    }
+};
+
+DemoUser.prototype.addPeer = function(peer) {
+    this.peers.push(peer);
+};
+
+DemoUser.prototype.getIdKey = function() {
+    var keys = JSON.parse(this.olmAccount.identity_keys());
+    return keys.curve25519;
+};
+
+DemoUser.prototype.generateKeys = function(callback) {
+    var self = this;
+    this.addTask("generate one time key", function(done) {
+        self.olmAccount.generate_one_time_keys(1);
+        done();
+    }, callback);
+};
+
+DemoUser.prototype.getOneTimeKey = function() {
+    var self = this;
+    var keys = JSON.parse(self.olmAccount.one_time_keys())
+        .curve25519;
+    for (key_id in keys) {
+        if (keys.hasOwnProperty(key_id)) {
+            return keys[key_id];
+        }
+    }
+    throw new Error("No one-time-keys generated");
+};
+
+/* ************************************************************************
+ *
+ * one-to-one messaging
+ */
+
+/**
+ * retrieve, or initiate, a one-to-one session to a given peer
+ */
+DemoUser.prototype.getPeerSession = function(peer, callback) {
+    var self = this;
+    var peerId = peer.getIdKey();
+    if (this.peerSessions[peerId]) {
+        callback(this.peerSessions[peerId]);
+        return;
+    }
+
+    this.addTask("get peer keys", function(done) {
+        key = peer.getOneTimeKey();
+        done(key);
+    }, function(ot_key) {
+        self.addTask("create peer session", function(done) {
+            var session = new Olm.Session();
+            session.create_outbound(self.olmAccount, peerId, ot_key);
+            self.peerSessions[peerId] = session;
+            done(session);
+        }, callback);
+    });
+};
+
+/**
+ * encrypt a one-to-one message and prepare it for sending to a peer
+ */
+DemoUser.prototype.sendToPeer = function(peer, message, callback) {
+    var self = this;
+    this.getPeerSession(peer, function(session) {
+        self.addTask("encrypt one-to-one message", function(done) {
+            var encrypted = session.encrypt(message);
+            var packet = {
+                sender_key: self.getIdKey(),
+                ciphertext: encrypted,
+            };
+            var json = JSON.stringify(packet);
+
+            var el = buttonAndTextElement("send", json, function(ev) {
+                peer.receiveOneToOne(json);
+            });
+            self.cipherOutputDiv.appendChild(el);
+            done();
+        }, callback);
+    });
+};
+
+/**
+ * handler for receiving a one-to-one message
+ */
+DemoUser.prototype.receiveOneToOne = function(jsonpacket) {
+    var self = this;
+    var el = buttonAndTextElement("decrypt", jsonpacket, function(ev) {
+        var sender = JSON.parse(jsonpacket).sender_key;
+        self.decryptOneToOne(jsonpacket, function(result) {
+
+            var el2 = document.createElement("tt");
+            el.appendChild(el2);
+
+            var content = document.createTextNode(" -> "+result);
+            el2.appendChild(content);
+
+            var body = JSON.parse(result);
+
+            // create a new inbound session if we don't yet have one
+            if (!self.peerGroupSessions[sender] ||
+                   !self.peerGroupSessions[sender][body.session_id]) {
+                self.createInboundSession(
+                    sender, body.session_id, body.message_index, body.session_key
+                );
+            }
+        });
+    });
+    this.cipherInputDiv.appendChild(el);
+};
+
+/**
+ * add a task to decrypt a one-to-one message. Calls the callback with the
+ * decrypted plaintext
+ */
+DemoUser.prototype.decryptOneToOne = function(jsonpacket, callback) {
+    var self = this;
+    self.addTask("decrypt one-to-one message", function(done) {
+        var packet = JSON.parse(jsonpacket);
+        var peerId = packet.sender_key;
+
+        var session = self.peerSessions[peerId];
+        var plaintext;
+        if (session) {
+            plaintext = session.decrypt(packet.ciphertext.type, packet.ciphertext.body);
+            done(plaintext);
+            return;
+        }
+
+        if (packet.ciphertext.type != 0) {
+            throw new Error("Unknown one-to-one session");
+        }
+
+        session = new Olm.Session();
+        session.create_inbound(self.olmAccount, packet.ciphertext.body);
+        self.peerSessions[peerId] = session;
+        plaintext = session.decrypt(packet.ciphertext.type, packet.ciphertext.body);
+        done(plaintext);
+    }, callback)
+};
+
+/* ************************************************************************
+ *
+ * group messaging
+ */
+
+
+/**
+ * retrieve, or initiate, an outbound group session
+ */
+DemoUser.prototype.getGroupSession = function() {
+    if (this.groupSession) {
+        return this.groupSession;
+    }
+
+    this.groupSession = new Olm.OutboundGroupSession();
+    this.groupSession.create();
+
+    var keymsg = {
+        "session_id": this.groupSession.session_id(),
+        "session_key": this.groupSession.session_key(),
+        "message_index": this.groupSession.message_index(),
+    };
+    var jsonmsg = JSON.stringify(keymsg);
+
+    for (var i = 0; i < this.peers.length; i++) {
+        var peer = this.peers[i];
+        this.sendToPeer(peer, jsonmsg);
+    }
+
+    return this.groupSession;
+};
+
+/**
+ * add a task to create an inbound group session
+ */
+DemoUser.prototype.createInboundSession = function(
+    peer_id, session_id, message_index, session_key, callback
+) {
+    var self = this;
+    this.addTask("init inbound session", function(done) {
+        session = new Olm.InboundGroupSession();
+        session.create(message_index, session_key);
+        if (!self.peerGroupSessions[peer_id]) {
+            self.peerGroupSessions[peer_id] = {};
+        }
+        self.peerGroupSessions[peer_id][session_id] = session;
+        done(session);
+    }, callback);
+};
+
+/**
+ * handler for receiving a group message
+ */
+DemoUser.prototype.receiveGroup = function(jsonpacket) {
+    var self = this;
+    var el = buttonAndTextElement("decrypt", jsonpacket, function(ev) {
+        self.decryptGroup(jsonpacket, function(result) {
+            var el2 = document.createElement("tt");
+            el.appendChild(el2);
+
+            var content = document.createTextNode(" -> "+result);
+            el2.appendChild(content);
+        });
+    });
+    this.groupInputDiv.appendChild(el);
+};
+
+/**
+ * add a task to decrypt a received group message. Calls the callback with the
+ * decrypted plaintext
+ */
+DemoUser.prototype.decryptGroup = function(jsonpacket, callback) {
+    var self = this;
+    this.addTask("decrypt group message", function(done) {
+        var packet = JSON.parse(jsonpacket);
+
+        var sender = packet.sender_key;
+        var session_id = packet.session_id;
+
+        var peer_sessions = self.peerGroupSessions[sender];
+        if (!peer_sessions) {
+            throw new Error("No sessions for sender "+sender);
+        }
+
+        var session = peer_sessions[session_id];
+        if (!session) {
+            throw new Error("Unknown session id " + session_id);
+        }
+
+        var plaintext = session.decrypt(packet.body);
+        done(plaintext);
+    }, callback);
+};
+
+
+
+/**
+ * add a task to encrypt, and prepare for sending, a group message.
+ *
+ * Will create a group session if necessary
+ */
+DemoUser.prototype.encrypt = function(message) {
+    var self = this;
+    var session = this.getGroupSession();
+
+    self.addTask("encrypt group message", function(done) {
+        var encrypted = session.encrypt(message);
+        var packet = {
+            sender_key: self.getIdKey(),
+            session_id: session.session_id(),
+            body: encrypted,
+        };
+        var json = JSON.stringify(packet);
+
+        var el = buttonAndTextElement("send", json, function(ev) {
+            for (var i = 0; i < self.peers.length; i++) {
+                var peer = self.peers[i];
+                peer.receiveGroup(json);
+            }
+        });
+        self.groupOutputDiv.appendChild(el);
+        done();
+    });
+};
+
+
+
+function initUserDiv(demoUser, div) {
+    demoUser.progressElement = div.getElementsByClassName("user_progress")[0];
+    demoUser.cipherOutputDiv = div.getElementsByClassName("user_cipher_output")[0];
+    demoUser.cipherInputDiv = div.getElementsByClassName("user_cipher_input")[0];
+    demoUser.groupOutputDiv = div.getElementsByClassName("group_output")[0];
+    demoUser.groupInputDiv = div.getElementsByClassName("group_input")[0];
+
+    var plain_input = div.getElementsByClassName("user_plain_input")[0];
+    var encrypt = div.getElementsByClassName("user_encrypt")[0];
+
+    encrypt.addEventListener("click", function() {
+        demoUser.encrypt(plain_input.value);
+    }, false);
+
+}
+
+function startDemo() {
+    var user1 = new DemoUser();
+    initUserDiv(user1, document.getElementById("user1"));
+    user1.generateKeys();
+
+    var user2 = new DemoUser();
+    initUserDiv(user2, document.getElementById("user2"));
+    user2.generateKeys();
+
+    user1.addPeer(user2);
+    user2.addPeer(user1);
+}
+
+
+document.addEventListener("DOMContentLoaded", startDemo, false);