Eiger test

The solution to code challenge

Pick a publicly available P2P node

I picked tendermint at version 0.34.X

How to execute handshake

Running node:

1. Clone tendermint repository:

   git clone https://github.com/tendermint/tendermint
   

2. Checkout to 0.34.X branch

   git checkout v0.34.x
   

3. Run node with (require docker and docker-compose installed)

   make build-linux && make localnet-start
   

   ** If you found any problems check this documentation: https://github.com/tendermint/tendermint/blob/0.35x/docs/tools/docker-compose.md
4. find chain_id parameter (will be needed on the client side)

   cat build/node0/config/genesis.json | grep chain_id
   

Running code challenge

1. Clone repository

   git clone https://git.sdr.ovh/sr/eiger-p2p
   

2. in run application with trace logging level and replace chain-D39Q88 with chain_id parameter. You can also run it as below and find remote chain_id in logs.

   RUST_LOG=eiger_p2p=trace cargo run -- --node 127.0.0.1:26659 --private-key 0x4d818e3802516dfb1c37a87576432bc210c9edf97e8b3217d806361c04d293fa --network chain-D39Q88
   

   ** It's possible to specify node ID that you want to connect:

   RUST_LOG=eiger_p2p=trace cargo run -- --node 127.0.0.1:26659 --private-key 0x4d818e3802516dfb1c37a87576432bc210c9edf97e8b3217d806361c04d293fa --network chain-D39Q88
   

It may require installed protoc check proto-build documentation if build fail.

Possible improvements:

1. share_eph_pubkey.rs is blocker for not using AsyncRead/AsyncWrite from beginning. Create simple module porotbuf-length-delimited that could handle with async and protobuf variant would be enough here. It allow also to drop protobuf dependency.
2. errors should be improvement. for example SecretConnectionError::HandshakeErr can internally hold i/o error. But this will be improved on it's own with 1.
3. secret key should be read from file and not pass as arg

Requirements check list:

• Both the target node and the handshake code should compile at least on Linux.
• The solution has to perform a full protocol-level (post-TCP/etc.) handshake with the target node.
  • secret connection
  • node version exchange
  • full node version verification
• The provided instructions should include information on how to verify that the handshake has concluded.
  • If handshake fail the application will exit with non-zero status code and error message
  • If handshake succeed the application will block on loop reading protobuf messages when debug level is enabled:

    2023-09-03T21:34:04.532535Z DEBUG eiger_p2p::peer: received raw protobuf frame (ping, pong, channelMsg): b"\n\x1a\x08\x08@\x10\x01\x1a\x02*\0\x1d\x1a\x1b\x08 \x10\x01\x1a\x15\n\x13\x08\x01\x18\x04 \xd5\x83\x02(\xff\xff\xff\xff\xff\xff\xff\xff\xff\x01"
    2023-09-03T21:34:05.622605Z DEBUG eiger_p2p::peer: received raw protobuf frame (ping, pong, channelMsg): b"\x08\x1a\x06\x10\x01\x1a\x02\n\0"
    2023-09-03T21:35:04.432639Z DEBUG eiger_p2p::peer: received raw protobuf frame (ping, pong, channelMsg): b"\x02\n\0"
    

• The solution can not depend on the code of the target node (but it can share some of its dependencies).
• The submitted code can not reuse entire preexisting handshake implementations like libp2p_noise/XX.