Adjust PartialMerkleTree arbitrary to satisfy decode checks
What the developer wrote
Authored by Mitchell Bagot
Adjust PartialMerkleTree arbitrary to satisfy decode checks
The PartialMerkleTreeDecoder has various checks in place that enforce
certain invariants for the decoded values. Arbitrary impls should
enforce the same invariants on constructed values as the decoders do.
Adjust PartialMerkleTree arbitrary impl to enforce the same invariants
as the PartialMerkleTreeDecoder.
What changed, and why it matters
This commit fixes a test-only code generator for a Bitcoin network data structure so that the generated examples respect the same padding rule used by the real decoder. It only affects fuzz/property tests and does not change production parsing or network behavior.
No production action required. If using property-based/fuzz tests with the arbitrary feature, ensure tests are rerun to confirm the generator now satisfies decoder checks.
Security signals we found
Invariant mismatch between decoder and arbitrary generator
Test-only arbitrary feature code change
No production parsing or consensus code modified
Evidence from the diff
The Arbitrary implementation for PartialMerkleTree in p2p/src/merkle_tree.rs previously produced a raw Vec
Changed components
p2p/src/merkle_tree.rsPartialMerkleTree Arbitrary implementationarbitrary featureInspect captured patch +5 / −1
diff --git a/p2p/src/merkle_tree.rs b/p2p/src/merkle_tree.rs
index 8f625f16..dc22f238 100644
--- a/p2p/src/merkle_tree.rs
+++ b/p2p/src/merkle_tree.rs
@@ -651,9 +651,13 @@ pub mod error {
#[cfg(feature = "arbitrary")]
impl<'a> Arbitrary<'a> for PartialMerkleTree {
fn arbitrary(u: &mut Unstructured<'a>) -> arbitrary::Result<Self> {
+ let mut bits = Vec::<bool>::arbitrary(u)?;
+ while bits.len() % 8 != 0 {
+ bits.push(false);
+ }
Ok(Self {
num_transactions: u.arbitrary()?,
- bits: Vec::<bool>::arbitrary(u)?,
+ bits,
hashes: Vec::<TxMerkleNode>::arbitrary(u)?,
})
}
Why this scored 18/100
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