crypto: fix Ed25519AggregateSignature serialization (#800)

Author: joyqvq

crypto/src/ed25519.rs

@@ -10,6 +10,7 @@ use serde::{
     Deserialize, Serialize,
 };
 use serde_bytes::{ByteBuf, Bytes};
+use serde_with::serde_as;
 use signature::{rand_core::OsRng, Signature, Signer, Verifier};
 use std::{
     fmt::{self, Display},
@@ -18,7 +19,7 @@ use std::{
 
 use crate::{
     pubkey_bytes::PublicKeyBytes,
-    serde_helpers::keypair_decode_base64,
+    serde_helpers::{keypair_decode_base64, Ed25519Signature as Ed25519Sig},
     traits::{
         AggregateAuthenticator, Authenticator, EncodeDecodeBase64, KeyPair, SigningKey,
         ToFromBytes, VerifyingKey,
@@ -59,9 +60,11 @@ pub struct Ed25519Signature {
     pub bytes: OnceCell<[u8; ED25519_SIGNATURE_LENGTH]>,
 }
 
+#[serde_as]
 #[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq, Default)]
-pub struct Ed25519AggregateSignature(pub Vec<ed25519_consensus::Signature>);
-
+pub struct Ed25519AggregateSignature(
+    #[serde_as(as = "Vec<Ed25519Sig>")] pub Vec<ed25519_consensus::Signature>,
+);
 ///
 /// Implement VerifyingKey
 ///

crypto/src/serde_helpers.rs

@@ -67,3 +67,39 @@ pub fn keypair_decode_base64<T: KeyPair>(value: &str) -> Result<T, eyre::Report>
     }
     Ok(kp)
 }
+
+pub struct Ed25519Signature;
+
+impl SerializeAs<ed25519_consensus::Signature> for Ed25519Signature {
+    fn serialize_as<S>(
+        source: &ed25519_consensus::Signature,
+        serializer: S,
+    ) -> Result<S::Ok, S::Error>
+    where
+        S: Serializer,
+    {
+        if serializer.is_human_readable() {
+            // Serialise to Base64 encoded String
+            base64ct::Base64::encode_string(source.to_bytes().as_ref()).serialize(serializer)
+        } else {
+            // Serialise to Bytes
+            Bytes::serialize_as(&source.to_bytes(), serializer)
+        }
+    }
+}
+
+impl<'de> DeserializeAs<'de, ed25519_consensus::Signature> for Ed25519Signature {
+    fn deserialize_as<D>(deserializer: D) -> Result<ed25519_consensus::Signature, D::Error>
+    where
+        D: Deserializer<'de>,
+    {
+        let bytes = if deserializer.is_human_readable() {
+            let s = String::deserialize(deserializer)?;
+            base64ct::Base64::decode_vec(&s).map_err(to_custom_error::<'de, D, _>)?
+        } else {
+            Bytes::deserialize_as(deserializer)?
+        };
+        ed25519_consensus::Signature::try_from(bytes.as_slice())
+            .map_err(to_custom_error::<'de, D, _>)
+    }
+}