Theodore/proofnarrowing #34

theodorebugnet · 2024-09-01T10:22:04Z

Add proof narrowing capabilities to the tree: given a range proof, supply two sets of leafs (contiguous with the edges of the original range), to generate a proof for the remaining sub-range.

This feature is useful for generating proofs of individual blobs in a Celestia namespace using the full-namespace proof returned by the GetSharesByNamespace RPC call.

Going above 20 was quickly becoming too slow anyway, so no real point in adding an extra dependency and more indirection.

Cargo.toml

src/lib.rs

src/nmt_proof.rs

src/simple_merkle/tree.rs

src/nmt_proof.rs

src/simple_merkle/tree.rs

preston-evans98

Based on the new test (which is very nice, btw!) this seems to work when the inputs are well-constructed. Unfortunately, it's pretty difficult to be confident about the correctness at a logical level given the current state of the code. Since this is pretty involved logic, I think it's probably worth investing in even more detailed explanations (probably including diagrams) in the core functions.

theodorebugnet · 2024-09-02T09:04:09Z

Actually your comment about the ranges is spot-on - the current test was missing a whole bunch of edge cases due to being non-inclusive. Whoops!
I'm fixing that now, and then it will probably be fine to assert that "it seems to work".

Happy to add some more comments and explanations, especially now that I've slept on it and can look at it from a slight distance.

theodorebugnet · 2024-09-02T13:20:55Z

By the way, the codecov.io token seems dead, so the badge in the README isn't updating anymore

- reverted the tendermint version bump - fixed edge cases on trees of total size 0 and 1 - fixed incorrect implementation in nmt_proof.rs (now just wraps the simple proof.rs) - fixed missing test cases for the above two issues - cleaned up inconsistent parameter naming to be more clear - cleaned up large argument sets in a few places to make data flow easier to follow - documented all assertions with a description of why they should never break - added documentation to the functions and descriptions of the narrowing logic

src/simple_merkle/tree.rs

preston-evans98

Thanks for making a pass on the naming and docs. It's much easier to understand this time around. Looks great, thanks @theodorebugnet!

theodorebugnet added 3 commits September 1, 2024 10:06

Added proof narrowing feature

36ac9dd

Remove test macro

879a827

Going above 20 was quickly becoming too slow anyway, so no real point in adding an extra dependency and more indirection.

Version bump, small cleanups, README

b4ca705

theodorebugnet requested a review from preston-evans98 September 1, 2024 10:24