fixup! Move invoice signing behind KeysInterface

Author: valentinewallace

lightning/src/chain/keysinterface.rs

@@ -25,7 +25,7 @@ use bitcoin::hashes::sha256d::Hash as Sha256dHash;
 use bitcoin::hash_types::WPubkeyHash;
 
 use bitcoin::secp256k1::key::{SecretKey, PublicKey};
-use bitcoin::secp256k1::{Message, Secp256k1, Signature, Signing};
+use bitcoin::secp256k1::{Secp256k1, Signature, Signing};
 use bitcoin::secp256k1::recovery::RecoverableSignature;
 use bitcoin::secp256k1;
 
@@ -1056,12 +1056,7 @@ impl KeysInterface for KeysManager {
 	}
 
 	fn sign_invoice(&self, invoice_preimage: Vec<u8>) -> Result<RecoverableSignature, ()> {
-		let secp_ctx = Secp256k1::new();
-		let mut raw_hash: [u8; 32] = Default::default();
-		raw_hash.copy_from_slice(&Sha256::hash(&invoice_preimage)[..]);
-		let msg_hash = Message::from_slice(&raw_hash[..])
-			.expect("Hash is 32 bytes long, same as MESSAGE_SIZE");
-		Ok(secp_ctx.sign_recoverable(&msg_hash, &self.get_node_secret()))
+		Ok(self.secp_ctx.sign_recoverable(&hash_to_message!(&Sha256::hash(&invoice_preimage)), &self.get_node_secret()))
 	}
 }