Add TreeHash trait to all types and structs

eth2/utils/bls/src/signature.rs

@@ -1,4 +1,4 @@
-use super::ssz::{decode_ssz_list, Decodable, DecodeError, Encodable, SszStream};
+use super::ssz::{decode_ssz_list, hash, Decodable, DecodeError, Encodable, SszStream, TreeHash};
 use super::{PublicKey, SecretKey};
 use bls_aggregates::Signature as RawSignature;
 
@@ -57,6 +57,12 @@ impl Decodable for Signature {
     }
 }
 
+impl TreeHash for Signature {
+    fn hash_tree_root(&self) -> Vec<u8> {
+        hash(&self.0.as_bytes())
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::super::ssz::ssz_encode;