What the developer wrote
Authored by Mitchell Bagot
Change TapTweak to take self by ref
The TapTweak trait in bitcoin::key currently consumes the untweaked
key to construct the tweaked key. While this is mostly fine for users
who manually call into it, it prevents clean usage in functions that
take Keypair refs.
Change TapTweak::tap_tweak to take self by ref instead of by value.
What changed, and why it matters
This is a small API ergonomics change in a Rust Bitcoin library. A function called tap_tweak is changed so callers pass a reference to the key instead of giving up ownership of the key. It does not fix a bug or vulnerability; it makes the library easier to use in code that holds key references.
No security action required. Treat as a normal API improvement. Review downstream code only if the signature change affects custom trait implementations or borrow-checker expectations.
Security signals we found
No strong security signals were identified.
Evidence from the diff
The TapTweak trait’s tap_tweak method signature is changed from taking self by value to taking &self. Implementations for UntweakedPublicKey and UntweakedKeypair are updated to dereference or reference self as needed. The cryptographic computation is unchanged. This is a non-breaking source change for most callers and is purely an API usability improvement.
Changed components
bitcoin/src/crypto/key.rsTapTweak traitUntweakedPublicKey::tap_tweakUntweakedKeypair::tap_tweakInspect captured patch +5 / −5
diff --git a/bitcoin/src/crypto/key.rs b/bitcoin/src/crypto/key.rs
index 4d7a7ee3..de717466 100644
--- a/bitcoin/src/crypto/key.rs
+++ b/bitcoin/src/crypto/key.rs
@@ -118,7 +118,7 @@ pub trait TapTweak {
/// # Returns
///
/// The tweaked key, with the required parity.
- fn tap_tweak(self, merkle_root: Option<TapNodeHash>) -> Self::TweakedAux;
+ fn tap_tweak(&self, merkle_root: Option<TapNodeHash>) -> Self::TweakedAux;
/// Directly converts an [`UntweakedPublicKey`] to a [`TweakedPublicKey`].
///
@@ -144,8 +144,8 @@ impl TapTweak for UntweakedPublicKey {
/// # Returns
///
/// The tweaked key and its parity.
- fn tap_tweak(self, merkle_root: Option<TapNodeHash>) -> TweakedPublicKey {
- let tweak = TapTweakHash::from_key_and_merkle_root(self, merkle_root).to_scalar();
+ fn tap_tweak(&self, merkle_root: Option<TapNodeHash>) -> TweakedPublicKey {
+ let tweak = TapTweakHash::from_key_and_merkle_root(*self, merkle_root).to_scalar();
let output_key = self.add_tweak(&tweak).expect("Tap tweak failed");
debug_assert!(self.tweak_add_check(&output_key, tweak));
@@ -171,8 +171,8 @@ impl TapTweak for UntweakedKeypair {
/// # Returns
///
/// The tweaked keypair.
- fn tap_tweak(self, merkle_root: Option<TapNodeHash>) -> TweakedKeypair {
- let pubkey = XOnlyPublicKey::from_keypair(&self);
+ fn tap_tweak(&self, merkle_root: Option<TapNodeHash>) -> TweakedKeypair {
+ let pubkey = XOnlyPublicKey::from_keypair(self);
let tweak = TapTweakHash::from_key_and_merkle_root(pubkey, merkle_root).to_scalar();
let tweaked = self.as_inner().add_xonly_tweak(&tweak).expect("Tap tweak failed");
TweakedKeypair::dangerous_assume_tweaked(Self::from(tweaked))
Why this scored 19/100
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