Handle merge fork in web3signer (#2631)

Author: paulhauner

validator_client/src/signing_method.rs

@@ -28,6 +28,7 @@ pub enum Error {
     Web3SignerJsonParsingFailed(String),
     ShuttingDown,
     TokioJoin(String),
+    MergeForkNotSupported,
 }
 
 /// Enumerates all messages that can be signed by a validator.
@@ -158,7 +159,7 @@ impl SigningMethod {
                     SignableMessage::RandaoReveal(epoch) => {
                         Web3SignerObject::RandaoReveal { epoch }
                     }
-                    SignableMessage::BeaconBlock(block) => Web3SignerObject::beacon_block(block),
+                    SignableMessage::BeaconBlock(block) => Web3SignerObject::beacon_block(block)?,
                     SignableMessage::AttestationData(a) => Web3SignerObject::Attestation(a),
                     SignableMessage::SignedAggregateAndProof(a) => {
                         Web3SignerObject::AggregateAndProof(a)

validator_client/src/signing_method/web3signer.rs

@@ -1,5 +1,6 @@
 //! Contains the types required to make JSON requests to Web3Signer servers.
 
+use super::Error;
 use serde::{Deserialize, Serialize};
 use types::*;
 
@@ -66,13 +67,14 @@ pub enum Web3SignerObject<'a, T: EthSpec> {
 }
 
 impl<'a, T: EthSpec> Web3SignerObject<'a, T> {
-    pub fn beacon_block(block: &'a BeaconBlock<T>) -> Self {
+    pub fn beacon_block(block: &'a BeaconBlock<T>) -> Result<Self, Error> {
         let version = match block {
             BeaconBlock::Base(_) => ForkName::Phase0,
             BeaconBlock::Altair(_) => ForkName::Altair,
+            BeaconBlock::Merge(_) => return Err(Error::MergeForkNotSupported),
         };
 
-        Web3SignerObject::BeaconBlock { version, block }
+        Ok(Web3SignerObject::BeaconBlock { version, block })
     }
 
     pub fn message_type(&self) -> MessageType {