Require the high-level sign traits instead of `SignFn` in bindings
What the developer wrote
Authored by Matt Corallo
Require the high-level sign traits instead of `SignFn` in bindings
Methods like `StaticInvoice::sign` have their own signing-function
traits, so there's no actual need to use `SignFn` directly, its
just a useful generic wrapper. Sadly, because it uses `AsRef`
bounds, which aren't really practical to map in bindings, we can't
really expose it directly in bindings. Because there's an
alternative and its tricky to expose, we simply mark it no-export
here.
What changed, and why it matters
This commit is a documentation-only change in the Rust Lightning library. It adds a comment explaining that a generic signing helper trait called SignFn is intentionally not exposed to language bindings (for users of other programming languages), because each specific signing method already has its own trait and the generic wrapper is awkward to map across languages. No code behavior changed, and there is no security fix or vulnerability here.
No action required. This is a non-security, developer-experience/documentation change.
Security signals we found
No strong security signals were identified.
Evidence from the diff
The diff adds a rustdoc comment to the SignFn trait in lightning/src/offers/merkle.rs stating it is not exported to bindings users and that per-signed-type signing function traits should be used instead. The trait remains pub for Rust callers; only the bindings generator is told to skip it. There are no logic, API, or cryptographic changes.
Changed components
lightning/src/offers/merkle.rs documentationInspect captured patch +3 / −0
diff --git a/lightning/src/offers/merkle.rs b/lightning/src/offers/merkle.rs
index 4f27130..1a38fe5 100644
--- a/lightning/src/offers/merkle.rs
+++ b/lightning/src/offers/merkle.rs
@@ -94,6 +94,9 @@ pub enum SignError {
}
/// A function for signing a [`TaggedHash`].
+///
+/// This is not exported to bindings users as signing functions should just be used per-signed-type
+/// instead.
pub trait SignFn<T: AsRef<TaggedHash>> {
/// Signs a [`TaggedHash`] computed over the merkle root of `message`'s TLV stream.
fn sign(&self, message: &T) -> Result<Signature, ()>;
Why this scored 15/100
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