Graphical User Interface (GUI)

Launch unMessage’s GUI with:

$ unmessage-gui

You are taken to the Start Peer tab and you are required to pick any name you wish to use and press Start:

../_images/start-gui.png

Start Peer window

Tor is launched and if this is the first time you use that name, your Onion Service and Double Ratchet keys are created and you are ready to receive and send requests to initialize conversations. unMessage displays this bootstrap process:

../_images/bootstrap-gui.png

Bootstrap window

The Copy buttons at the top bar can be used to copy information the other peers need to send you requests. You must share both your identity address and key:

charlie@jt6zabesvrhxvhee.onion:50001 v4kU6s+NuJW/Znbjz0AxoI9Gvl1XDS5eiOTm6cE38E4=

Sending Requests

Press the New chat button at the top bar to open the Request window. Provide the identity address and key of the peer you wish to contact:

../_images/req-send-gui.png

Outbound request window

An identity address is provided in the format <name>@<onion address>, where the <name> is only a local identifier of the peer and you can pick any name you wish to call them.

Receiving Requests

Inbound requests are notified in a new window with the information of the peer who sent the request:

../_images/req-accept-gui.png

Inbound request window

As mentioned previously, peer names are local and when accepting a request you can pick another one to call them instead of using the one they sent.

Chatting

unMessage creates tabs for each peer you have a conversation with. Within each tab, besides composing messages and sending (clicking Send or pressing the Enter key) there are some actions available.

../_images/msg-gui.png

Chat tab

Notifying Presence

If you wish to notify the peer whenever you go online or offline, check Send Presence and unMessage will start to send them notifications of these events.

Verifying

If you have some secure communication channel established with the other peer, ask them for their unMessage public identity key. Click Verify and enter the key:

../_images/verify-gui.png

Verification window

If the key matches, the peer will be verified and now you have established a verified and secure communication channel:

../_images/level-verify-gui.png

Verified conversation

Authenticating

The authentication of a conversation works by prompting both peers for a secret (which was exchanged through some other secure channel) and if the secrets provided match, they are sure they are chatting with the right person. Click Authenticate and provide the secret:

../_images/auth-gui.png

Authentication window

An authentication session is created when the secrets are exchanged and is valid until one of the peers disconnect. When it happens, the conversation is not authenticated anymore and a new session must be initialized when the peers reconnect.

../_images/level-auth-gui.png

Authenticated conversation

Assuming that one of the peers might be an attacker, this process is done with the Socialist Millionaire Protocol by comparing the secrets without actually disclosing them.

Authentication Levels

As noticed, unMessage conversations have three authentication levels:

  1. Unverified Conversation
  2. Verified Conversation
  3. Authenticated Conversation

When the conversation is established, its level is Unverified Conversation because unMessage does not know if you are sure that the peer’s identity key is actually theirs.

If you follow the Verifying section, the level changes to Verified Conversation and it persists for as long the conversation exists.

If you follow the Authenticating section, the level changes to Authenticated Conversation and it persists for as long the session exists. Once the session is over, the level drops to the identity key’s verification level: Unverified/Verified.

Important

The Authenticated level is stronger than the Verified level because the former is a short term verification that lasts only until the peers disconnect, while the latter is long term that lasts until the conversation is deleted (manually, by the user). That means that with a short term verification you are able to authenticate the peer at that exact time, while a long term verification means that you authenticated the peer in the past, but is not aware of a compromise in the future.

This feature aims to increase unMessage’s security by identifying an attack that is not covered by the scope of the Double Ratchet Algorithm: compromised keys.

Relaunching unMessage

unMessage remembers the last User Interface and Peer that you used. If you wish to use a shortcut, you may call:

unmessage