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function verify(bytes32 value, bytes encodedPath, bytes rlpParentNodes, bytes32 root) internal pure returns (bool) { |
We are using MerklePatriciaProof.sol
library in Mosaic-contracts. While testing, we came across a use case where verification of Merkle proof failed for a valid proof.
After debugging, a scenario is observed for the Merkle proof which has an extension node in between.
On L55,_nibblesToTraverse
function increases pathPtr with the size of the extension node key.
pathPtr += _nibblesToTraverse(RLP.toData(currentNodeList[0]), path, pathPtr);
Then on L65, updated pathPtr
is passed. Here _nibblesToTraverse
will return 0
because the key of the extension node will not match this time. Hence false
is returned from the function and Merkle proof verification will fail.
Possible fix for the issue is to preserve pathPtr
before updating on L55 and pass the preserved pathPtr
on L65. Refer this commit.
Below are the parameters which were passed to the verify
function.
value : 0x5fe7f977e71dba2ea1a68e21057beebb9be2ac30c6410aa38d4f3fbe41dcffd2
encodedPath : 0x40769c9cc6db1aff35e37923897950227d2a87c95ef0101b2a0233740f2ce00d
rlpParentNodes : 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
root : 0xa506e7e444fc636360bb593a808f41f126a8813ea71410d4515987eacc594380