Allow downloading of large tests from EF github and fix issues with serde

eth2/utils/bls/src/signature.rs

@@ -1,5 +1,5 @@
 use super::serde_vistors::HexVisitor;
-use super::{PublicKey, SecretKey};
+use super::{PublicKey, SecretKey, BLS_SIG_BYTE_SIZE};
 use bls_aggregates::Signature as RawSignature;
 use hex::encode as hex_encode;
 use serde::de::{Deserialize, Deserializer};
@@ -63,7 +63,7 @@ impl Signature {
     /// Returns a new empty signature.
     pub fn empty_signature() -> Self {
         // Set RawSignature = infinity
-        let mut empty: Vec<u8> = vec![0; 96];
+        let mut empty: Vec<u8> = vec![0; BLS_SIG_BYTE_SIZE];
         empty[0] += u8::pow(2, 6) + u8::pow(2, 7);
         Signature {
             signature: RawSignature::from_bytes(&empty).unwrap(),
@@ -121,6 +121,7 @@ impl TreeHash for Signature {
 }
 
 impl Serialize for Signature {
+    /// Serde serialization is compliant the Ethereum YAML test format.
     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
     where
         S: Serializer,
@@ -130,14 +131,15 @@ impl Serialize for Signature {
 }
 
 impl<'de> Deserialize<'de> for Signature {
+    /// Serde serialization is compliant the Ethereum YAML test format.
     fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
     where
         D: Deserializer<'de>,
     {
-        let bytes = deserializer.deserialize_str(HexVisitor)?;
-        let (pubkey, _) = <_>::ssz_decode(&bytes[..], 0)
+        let bytes: Vec<u8> = deserializer.deserialize_str(HexVisitor)?;
+        let signature = Signature::from_bytes(&bytes[..])
             .map_err(|e| serde::de::Error::custom(format!("invalid ssz ({:?})", e)))?;
-        Ok(pubkey)
+        Ok(signature)
     }
 }
 
@@ -165,7 +167,7 @@ mod tests {
 
         let sig_as_bytes: Vec<u8> = sig.as_raw().as_bytes();
 
-        assert_eq!(sig_as_bytes.len(), 96);
+        assert_eq!(sig_as_bytes.len(), BLS_SIG_BYTE_SIZE);
         for (i, one_byte) in sig_as_bytes.iter().enumerate() {
             if i == 0 {
                 assert_eq!(*one_byte, u8::pow(2, 6) + u8::pow(2, 7));