core-lightning/TODO.md

Looking for things to hack on?

I've marked things as simple if you want something easy to work on!

Cleanups

• Wean off openssl's -lcrypto

  • (simple) use libsodium for all RNG
  • (simple) use libbase58

• Remove our specific libsecp256k1 in secp256k1/ and use the installed one.

  • Implement sig_valid, using secp256k1_ecdsa_signature_normalize
  • Use secp256k1_ecdsa_signature_parse_compact/_serialize_compact in signature_to_proto

Minor improvements

• Make json_get_params fail if unknown parameters are specified by user.
• Print backtrace in log_crash
• Support locktime in blocks in accept_pkt_open, accept_pkt_htlc_add, commit_tx_depth
• When unpacking a packet, reject any with an unknown odd-numbered field as per BOLT #2.
• Provide details (string) when a command fails because state() returns CMD_FAIL
• logging: add log_struct() for common structs.
• Limit total number of peers in new_peer, or at least in peer_connected_in.
• logging: add IO logging for peers.
• Add history RPC command which shows all prior commit txs.
• Improve getpeers to show status of peers when connecting, DNS lookups etc.
• Add pings to protocol
  • Timeout a peer if they don't respond in a given time (eg. 2 pings)
• Add timers to drop peer if we approach timeout for HTLCs and they're still uncommitted to closing it (see BOLT #2 "Risks With HTLC Timeouts").

Testing:

• Add more unit tests in bitcoin/test.
• Test more scenarios with daemon/test/test.sh
• Implement compile-time crypto-free mode
  • Implement canned conversation files for fuzz testing (eg AFL).
• Write canned input/output test cases for various conversations, and include them in a form suitable for other implementations to test.

Major improvements:

• Track fee estimation for each new block.

  • (MAJOR) Implement fee renegotiation acceptance.
  • (MAJOR) Implement fee renegotiation as fee rate changes.

• Don't fail funding if fees insufficient, fall back as per BOLT #2.

• (MAJOR) Do proper close, still allowing ongoing HTLCs to resolve.

• (MAJOR) Implement reconnection.

• Save preimages in shachain.

  • (MAJOR) Implement persistence.

• (MAJOR) Implement onion

  • (MAJOR) Implement routing
  • (MAJOR) Implement failure messages

Other

• Grep for other FIXMEs and fix one :)
• Look on https://github.com/ElementsProject/lightning/issues

Happy hacking!
Rusty.