DHT Swarm

this is a practice in UDP Multicasting, and DHT experimentation in a localhost. the idea is to run as many instances of this daemon as you want, and all instances will find eachother via udp multicast and build a dht network. each peer of the network generates an ed25519 keypair, and binds to a random port. the port is an http service that takes requests at these endpoints:

• /dht
• /api

the /dht endpoint serves websocket rpc requests

the /api endpoint serves https curl requests. right now the only implemented rpc call is "ping"

its all a work-in-progress. more work to be added soon.

swarm

as each instance of this is executed on the network (or on the same computer), every 5 seconds the instance broadcasts a UDP packet containing a newly generated public key, a random service port, and consequentially its own ip address from the IP packet. each time an instance receives a UDP multicast packet, it checks the new peer's public key against a map, if its a newly found peer, it will log it to stdout, and add it to the map in memory. the bucket is printed every 5 seconds

demo

1. git clone this project, or download here: master.zip
2. use ./build.sh to build in docker, or just use go build
3. open two terminal windows:

• in one terminal, run ./demo.sh to spawn ten instances
• in another terminal curl the api to perform an RPC ping

curl -kvs https://localhost:port/api/ping

^^^ this will tell the peer to perform an RPC ping to the top three closest peers in the bucket.

note

some things to note:

• all peers use 32 byte length keys for node-IDs, dht distance metrics, and i plan on using sha256 hashes for the dht keys, this parts from the kademlia standard
• all peer dht connections use a self-signed certificate, i dunno, for fun
• only the "ping" rpc method is implemented right now, more to come
• secret handshake is used to ensure each peer is connecting to the right peerID (public-key validation)
• this project is intended to be a local test-bed for playing with DHTs, hence the api endpoint