Improvements from previous update: 1) Improved and a stable UI for mobile application 2) A dedicated TCP server on a different port on home node instead of using fproxy for handling connection to mobiles (on the lines of SimpleToadletServer) 3) This server issues a self-signed SSL certificate 4) A signed MDNS service using ECDSA (modification on MDNS discovery plugin) broadcasts this server MDNS packet contains EC signature(homenode name,port,SPKI-hash of server certificate) and EC public key to verify this signature 5) Mobile app identifies this service on home LAN, tries to establish SSL connection with the server and pulls the node reference 6) Mobile App can connect to another such app via WiFi Direct (WPA using Push Button Authentication)
More Details + Some Problems Faced: For #1 UI Simple UI on a dark background to allow only basic functionality, all handled by touch buttons only (no savvy stuff) Divided the screen into two fragments, Upper fragment displays messages and lower fragment is used to interact with user For #2 TCP Server Tried to extend SimpleToadletServer.java to make another server on different port but it was heavily linked to FProxy and any extension required rewriting most of the code. So, I started from scratch and generously copy-pasted required code from SimpleToadletServer. For#3 SSL Authentication I couldn't get the SSL.java in freenet.crypt folder to work. I was getting all kinds of errors and exceptions.. http://pastebin.com/ZmJwdwMB for example To save time, I discarded SSL.java and used a latest SSL implementation from bouncy castle. A new class BCSSLNetworkInterface extends freenet.io,NetworkInterface and essentially does the same work as SSLNetworkInterface. So #2 server utilizes this BCSSLNetworkInterface to create ServerSockets This is only a one way server authentication. Client (mobile app isn't authenticated). Client could be authenticated in a way when the user manually verifies the received node references on the homenode (by a button click) after they synchronize For #4 MDNS Broadcast: ECDSA implementation is from Bouncy Castle The SPKI (public key) is extracted from the self signed certificate from #3 BC-SSL-TCP server and its SHA1 hash is added to the broadcast For #5 MDNS Reception on mobile app Once mobile app verifies the signature, it extracts SPKI hash from MDNS packet. In the process of SSL Handshake with the server, it verifies the obtained certificate by comparing the two SHA1 hashes. Once a secure connection is established, it pulls the home node reference. A modified version of Moxie's Android Pinning library is used to authenticate using SPKI ..https://github.com/moxie0/AndroidPinning For #6 WiFi Direct Connection between two apps Used the example provided in android SDK as the base to establish Wi-Fi Direct Connection http://developer.android.com/guide/topics/connectivity/wifip2p.html#discovering Work to be done: Minor: 1) Extend support to USB tethered and bluetooth connections with home node on the mobile. Requires no change on home node code as the server is on 0.0.0.0 However, on the mobile, listening multicast on 0.0.0.0 is disallowed to save battery and so we are listening only multicast *wifi* packets presently. So, I need to add callbacks to discover newly tethered networks and start listening on them 2) Add option on the home TCP server to accept new node references from the mobile and display them for user verification Major: Add other methods for reference exchange between apps apart from WiFI Direct 1) QR based exchange 2) Bluetooth based 3) Wifi Hotspot on one mobile with normal wifi on other mobile More discussion is necessary in this respect Also, I've realized that next step in this project would be to support invites I plan to complete the minor works this week so that a basic level functionality is achieved i.e. Two people with *high end* mobiles having this daeknet app should be able to exchange nodereferences and sync them up back home The corresponding code: Modified Fred: https://github.com/NiteshBharadwaj/fred-staging/tree/next/src Modified MDNS DIscovery: https://github.com/NiteshBharadwaj/plugin-MDNSDiscovery-official The app: https://github.com/NiteshBharadwaj/Freenet/tree/master/src/freenet/darknetconnector/FProxyConnector
