Move signature payload generation into signature scheme (#199)

Author: casey

src/signature.rs

@@ -32,15 +32,7 @@ impl Bech32m<2, { Signature::LEN }> for Signature {
 
 impl Display for Signature {
   fn fmt(&self, f: &mut Formatter) -> fmt::Result {
-    let (prefix, suffix) = self.scheme.prefix_and_suffix();
-
-    let payload = Bech32mPayload {
-      prefix,
-      data: self.inner.to_bytes(),
-      suffix: suffix.into(),
-    };
-
-    Self::encode_bech32m(f, payload)
+    Self::encode_bech32m(f, self.scheme.payload(self.inner))
   }
 }
 

src/signature_scheme.rs

@@ -88,15 +88,22 @@ impl SignatureScheme {
     }
   }
 
-  pub(crate) fn prefix_and_suffix(&self) -> ([Fe32; 2], &[u8]) {
+  pub(crate) fn payload(
+    &self,
+    signature: ed25519_dalek::Signature,
+  ) -> Bech32mPayload<2, 64, Vec<u8>> {
     let prefix = self.discriminant().prefix();
 
     let suffix = match self {
       SignatureScheme::Filepack | SignatureScheme::Ssh => &[],
       SignatureScheme::Pgp { hashed_area } => hashed_area.as_slice(),
     };
 
-    (prefix, suffix)
+    Bech32mPayload {
+      prefix,
+      data: signature.to_bytes(),
+      suffix: suffix.into(),
+    }
   }
 
   pub(crate) fn signed_data<'a>(&self, message: &'a SerializedMessage) -> Cow<'a, [u8]> {