DiodeClient

DiodeClient secure end-to-end encrypted connections between any two machines. Connections are established either through direct peer-to-peer TCP connections or bridged via the Diode network. To learn more about the decentralized Diode network visit https://diode.io/

Example usage with a simple server + client. For this to work open each in individual terminal:

# Server
DiodeClient.interface_add("example_server_interface")
address = DiodeClient.Base16.encode(DiodeClient.address())

{:ok, port} = DiodeClient.port_listen(5000)
spawn_link(fn ->
  IO.puts("server #{address} started")
  {:ok, ssl} = DiodeClient.port_accept(port)
  peer = DiodeClient.Port.peer(ssl)
  IO.puts("got a connection from #{Base.encode16(peer)}")
  :ssl.controlling_process(ssl, self())
  :ssl.setopts(ssl, [packet: :line, active: true])
  for x <- 1..10 do
    IO.puts("sending message #{x}")
    :ssl.send(ssl, "Hello #{Base.encode16(peer)} this is message #{x}\n")
  end
  receive do
    {:ssl_closed, _ssl} -> IO.puts("closed!")
  end
end)

And the client. Here insert in the server address the address that has been printed above. For example server_address = "0x389eba94b330140579cdce1feb1a6e905ff876e6"

  # Client: Below enter your server address
  server_address = "0x389eba94b330140579cdce1feb1a6e905ff876e6"
  DiodeClient.interface_add("example_client_interface")

  spawn_link(fn ->
    {:ok, ssl} = DiodeClient.port_connect(server_address, 5000)
    :ssl.controlling_process(ssl, self())
    :ssl.setopts(ssl, [packet: :line, active: true])
    Enum.reduce_while(1..10, nil, fn _, _ ->
      receive do
        {:ssl, _ssl, msg} -> {:cont, IO.inspect(msg)}
        other -> {:halt, IO.inspect(other)}
      end
    end)
    :ssl.close(ssl)
    IO.puts("closed!")
  end)

And the client. Here insert in the server address the address that has been printed above. For example server_address = "0x389eba94b330140579cdce1feb1a6e905ff876e6"

  # Client:
  server_address = "0x389eba94b330140579cdce1feb1a6e905ff876e6"
  DiodeClient.interface_add("example_client_interface")

  spawn_link(fn ->
    {:ok, ssl} = DiodeClient.port_connect(server_address, 5000)
    :ssl.controlling_process(ssl, self())
    :ssl.setopts(ssl, [packet: :line, active: true])
    Enum.reduce_while(1..10, nil, fn _, _ ->
      receive do
        {:ssl, _ssl, msg} -> {:cont, IO.inspect(msg)}
        other -> {:halt, IO.inspect(other)}
      end
    end)
    :ssl.close(ssl)
    IO.puts("closed!")
  end)

Blockchain Interaction

For limited access to supported blockchain source of truth data :diode_client supports reading from smart contracts and calling contract methods. For each supported blockchain there is a Shell configured, currently supported blockchains are:

• Diode L1 (DiodeClient.Shell) - deprecated
• Moonbeam (Diodeclient.Shell.Moonbeam) - https://moonbeam.network/
• Oasis Sapphire (DiodeClient.Shell.OasisSapphire) - https://oasis.net/sapphire

Each of these support call/5 and other methods to read contract data and send transactions.

Example of making a ZTNA contract call on Oasis Sapphire:

alias Diodeclient.{Base16, Shell}

Shell.OasisSapphire.call(
  Base16.decode("0xb78700e7254F54b418bdF6DE7109128D1Fe8E8DD"), 
  "getPropertyValue", 
  ["address", "string"], 
  [Base16.decode("0x90983fc294577b6f00CBd5D3b26aDf2e85Ca2Cac"), "public"], 
  result_types: "string"
)

Encryption and Authentication

For encryption standard TLS as builtin into Erlang from OpenSSL is used. For authentication though the Ethereum signature scheme using the elliptic curve secp256k1 is used. The generated public addresses of the form 0x389eba94b330140579cdce1feb1a6e905ff876e6 actually represent hashes of public keys. When opening a port using DiodeClient.port_open("0x389eba94b330140579cdce1feb1a6e905ff876e6", 5000) this first locates the correct peer and then uses cryptographic handshakes to ensure the peer is in fact in possession of the corresponding private key.

To this regard the DiodeClient will by default store private keys in local files. In the example above example_client_interface and example_server_interface. These represent both the address as well as the private key needed to authenticate as such.

Todos

• Add actual support for multiple interfaces in a single session
• Add standard contract call interfaces e.g. for BNS to be able to resolve human readable names such as somename.diode

Installation

The package can be installed by adding diode_client to your list of dependencies in mix.exs:

def deps do
  [
    {:diode_client, "~> 1.1"}
  ]
end