Add {Lower,Upper}Hex to ecdsa::Signature
What the developer wrote
Authored by Mitchell Bagot
Add {Lower,Upper}Hex to ecdsa::Signature
The Taproot Signature type has Debug, Display, LowerHex and UpperHex
impls. The ECDSA signature, by contrast, only has Debug and Display.
Since the Display impl already displays a lowercase hex format,
explicit lower and uppercase hex formatting should be added and the
Display impl modified to call through to LowerHex.
Add LowerHex and UpperHex impls and modify Display to call through to
LowerHex in ecdsa::Signature.
Add tests to verify new behaviour.
What changed, and why it matters
This commit adds new ways to print ECDSA Bitcoin signatures as hexadecimal text (lowercase and uppercase), matching formatting already available for Taproot signatures. It also makes the existing Display implementation reuse the new LowerHex implementation. There is no security fix or behavior change that affects signatures themselves—only how they look when formatted as text.
No security action required; this is a routine API-consistency enhancement.
Security signals we found
No strong security signals were identified.
Evidence from the diff
The patch implements std::fmt::LowerHex and std::fmt::UpperHex for ecdsa::Signature under the ‘hex’ feature, and refactors fmt::Display to delegate to LowerHex. Serialization output is unchanged; only formatting traits are extended, with unit tests verifying {:x} and {:X} produce the expected hex strings.
Changed components
crypto/src/ecdsa.rsInspect captured patch +43 / −5
diff --git a/crypto/src/ecdsa.rs b/crypto/src/ecdsa.rs
index 8e6a603a..4c52f6d7 100644
--- a/crypto/src/ecdsa.rs
+++ b/crypto/src/ecdsa.rs
@@ -100,9 +100,23 @@ impl Signature {
#[cfg(feature = "hex")]
impl fmt::Display for Signature {
+ #[inline]
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { fmt::LowerHex::fmt(self, f) }
+}
+
+#[cfg(feature = "hex")]
+impl fmt::LowerHex for Signature {
+ #[inline]
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ self.serialize().fmt(f)
+ }
+}
+
+#[cfg(feature = "hex")]
+impl fmt::UpperHex for Signature {
#[inline]
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
- fmt::Display::fmt(&self.serialize(), f)
+ self.serialize().fmt(f)
}
}
@@ -437,14 +451,20 @@ mod tests {
#[cfg(feature = "alloc")]
const TEST_SIGNATURE_HEX: &str = "3046022100839c1fbc5304de944f697c9f4b1d01d1faeba32d751c0f7acb21ac8a0f436a72022100e89bd46bb3a5a62adc679f659b7ce876d83ee297c7a5587b2011c4fcc72eab45";
- #[test]
#[cfg(feature = "hex")]
#[cfg(feature = "alloc")]
- fn iterate_serialized_signature() {
- let sig = Signature {
+ fn sig() -> Signature {
+ Signature {
signature: secp256k1::ecdsa::Signature::from_str(TEST_SIGNATURE_HEX).unwrap(),
sighash_type: EcdsaSighashType::All,
- };
+ }
+ }
+
+ #[test]
+ #[cfg(feature = "hex")]
+ #[cfg(feature = "alloc")]
+ fn iterate_serialized_signature() {
+ let sig = sig();
assert_eq!(sig.serialize().iter().copied().collect::<Vec<u8>>(), sig.to_vec());
}
@@ -465,4 +485,22 @@ mod tests {
assert_eq!(sig_format, ser_format);
assert_eq!(sig_format, "3046");
}
+
+ #[test]
+ #[cfg(feature = "hex")]
+ #[cfg(feature = "alloc")]
+ fn sig_lower_hex() {
+ let want = "3046022100839c1fbc5304de944f697c9f4b1d01d1faeba32d751c0f7acb21ac8a0f436a72022100e89bd46bb3a5a62adc679f659b7ce876d83ee297c7a5587b2011c4fcc72eab4501";
+ let got = alloc::format!("{:x}", sig());
+ assert_eq!(got, want);
+ }
+
+ #[test]
+ #[cfg(feature = "hex")]
+ #[cfg(feature = "alloc")]
+ fn sig_upper_hex() {
+ let want = "3046022100839C1FBC5304DE944F697C9F4B1D01D1FAEBA32D751C0F7ACB21AC8A0F436A72022100E89BD46BB3A5A62ADC679F659B7CE876D83EE297C7A5587B2011C4FCC72EAB4501";
+ let got = alloc::format!("{:X}", sig());
+ assert_eq!(got, want);
+ }
}
Why this scored 20/100
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