chore(ampd-minor): update signers hash for multiversx after contracts…

… audit (#707)

ampd/src/mvx/mod.rs

@@ -24,15 +24,20 @@ pub struct WeightedSigners {
 
 impl WeightedSigners {
     pub fn hash(&self) -> Hash {
-        let mut encoded = Vec::new();
+        let mut encoded: Vec<Vec<u8>> = Vec::new();
+
+        encoded.push(usize_to_u32(self.signers.len()).to_vec());
 
         for signer in self.signers.iter() {
-            encoded.push(signer.signer.as_slice());
-            encoded.push(signer.weight.as_slice());
+            encoded.push(signer.signer.to_vec());
+
+            encoded.push(usize_to_u32(signer.weight.len()).to_vec());
+            encoded.push(signer.weight.to_vec());
         }
 
-        encoded.push(self.threshold.as_slice());
-        encoded.push(self.nonce.as_slice());
+        encoded.push(usize_to_u32(self.threshold.len()).to_vec());
+        encoded.push(self.threshold.to_vec());
+        encoded.push(self.nonce.to_vec());
 
         Keccak256::digest(encoded.concat()).into()
     }
@@ -76,10 +81,15 @@ fn uint256_to_compact_vec(value: Uint256) -> Vec<u8> {
     bytes[slice_from..].to_vec()
 }
 
+#[allow(clippy::cast_possible_truncation)]
+fn usize_to_u32(value: usize) -> [u8; 4] {
+    (value as u32).to_be_bytes()
+}
+
 pub fn ed25519_key(pub_key: &PublicKey) -> Result<[u8; 32], Error> {
-    return match pub_key {
+    match pub_key {
         PublicKey::Ed25519(ed25519_key) => Ok(<[u8; 32]>::try_from(ed25519_key.as_ref())
             .expect("couldn't convert pubkey to ed25519 public key")),
         _ => Err(Error::NotEd25519Key),
-    };
+    }
 }

ampd/src/mvx/verifier.rs

@@ -518,8 +518,9 @@ mod tests {
         // 0000000000000000000000000000000000000000000000000000000000000005 - the nonce (created_at date as uint256)
         let data = HexBinary::from_hex("0000000345e67eaf446e6c26eb3a2b55b64339ecf3a4d1d03180bee20eb5afdd23fa644f0000000101c387253d29085a8036d6ae2cafb1b14699751417c0ce302cfe03da279e6b5c040000000101dd9822c7fa239dda9913ebee813ecbe69e35d88ff651548d5cc42c033a8a667b000000010100000001020000000000000000000000000000000000000000000000000000000000000005")
             .unwrap();
+        // This hash is generated externally using the MultiversX Gateway contract and is 100% correct
         let signers_hash =
-            HexBinary::from_hex("29f81aa379fa1f5973d05dd25e5ae4bc1afa2aa30156b1db5ec437a46ba4fd28")
+            HexBinary::from_hex("ad334409a09406b82c1d0f86bdc0aa8f68950c996643c884e6be66e6ea821654")
                 .unwrap();
 
         let wrong_event = Events {