This addresses the last known deficiency of the eth_getProof
implementation. The previous code would return an error in the event
that the element was not found in the trie. EIP-1186 allows for
'negative' proofs where a proof demonstrates that an element cannot be
in the trie, so this commit updates the logic to support that case.
Co-authored-by: Jason Yellick <jason@enya.ai>
This PR extends the function merged in #7337 to cover the proof
generation paths as well.
The first commit simply migrates the internal proof checking code from
the rpc `eth_getProof` test to be available externally exported under
`turbo/trie`. In the process, it translates the in place testing
assertions to return more normally as errors and adapts to use the
pre-existing trie node types which are defined slightly differently
(although this code is still intended only for testing purposes).
The second commit refactors the existing trie fuzzing tests from the
previous PR and adds new fuzzing tests for the proof generation. In
order to validate the proofs, these fuzzing tests fundamentally do two
things. Firstly, after bootstrapping the test (by seeding, and modifying
the db), for each key we compute the 'naive' proof utilizing the
existing code in `proof.go` and the in memory `trie.Trie` structure. The
`trie.Trie` code actually had a couple small bugs which are fixed in
this PR (not handling value nodes, and not honoring the `NewTestRLPTrie`
contract of pre-RLP encoded nodes in proof generation). Secondly, we
re-compute the same proof for the flatDB production variant, and verify
that it is exactly the same proof as computed by the naive
implementation.
This fuzzing has been run for ~72 hours locally with no errors. Although
this code hasn't identified any new bugs in the proof generation path,
it improves coverage and should help to prevent regressions. Additional
extensions will be provided in a subsequent PR.
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Co-authored-by: Jason Yellick <jason@enya.ai>
According to EIP-1186 the `proof` parts of the response to eth_getProof
should be returned "starting with the stateRoot-Node, following the path
of the SHA3 (address) as key." Currently, the proof is returned in
traversal order, rather than from the root.
Although all of the proof elements are there and correct, this is
contrary to the EIP and will cause problems for some clients. The
existing rpc test uses a map to lookup proof elements by hash, rather
than by index, so this bug was not initially caught.
This commit fixes the behavior, updates the existing test, and adds
additional checks to the rpc test.
Co-authored-by: Jason Yellick <jason@enya.ai>
This PR completes the implementation of `eth_getProof` by adding support
for storage proofs.
Because storage proofs are potentially overlapping, the existing
strategy of simply aggregating all proofs together into a single result
was challenging. Instead, this commit rewires things to introduce a
ProofRetainer, which aggregates proofs and their corresponding nibble
encoded paths in the trie. Once all of the proofs have been aggregated,
the caller requests the proof result, which then iterates over the
aggregated proofs, placing each into the relevant proof array into the
result.
Although there are tests for `eth_getProof` as an RPC and for the new
`ProofRetainer` code, the code coverage for the proof generation over
complex tries is lacking. But, since this is not a new problem I'll plan
to follow up this PR with an additional one adding more coverage into
`turbo/trie`.
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Co-authored-by: Jason Yellick <jason@enya.ai>
