Use eth1_withdrawal_credentials in Test States (#3898)

* Use eth1_withdrawal_credential in Some Test States

* Update beacon_node/genesis/src/interop.rs

Co-authored-by: Michael Sproul <micsproul@gmail.com>

* Update beacon_node/genesis/src/interop.rs

Co-authored-by: Michael Sproul <micsproul@gmail.com>

* Increase validator sizes

* Pick next sync committee message

Co-authored-by: Michael Sproul <micsproul@gmail.com>
Co-authored-by: Paul Hauner <paul@paulhauner.com>

beacon_node/genesis/src/interop.rs

@@ -10,6 +10,20 @@ use types::{
 
 pub const DEFAULT_ETH1_BLOCK_HASH: &[u8] = &[0x42; 32];
 
+fn bls_withdrawal_credentials(pubkey: &PublicKey, spec: &ChainSpec) -> Hash256 {
+    let mut credentials = hash(&pubkey.as_ssz_bytes());
+    credentials[0] = spec.bls_withdrawal_prefix_byte;
+    Hash256::from_slice(&credentials)
+}
+
+fn eth1_withdrawal_credentials(pubkey: &PublicKey, spec: &ChainSpec) -> Hash256 {
+    let fake_execution_address = &hash(&pubkey.as_ssz_bytes())[0..20];
+    let mut credentials = [0u8; 32];
+    credentials[0] = spec.eth1_address_withdrawal_prefix_byte;
+    credentials[12..].copy_from_slice(fake_execution_address);
+    Hash256::from_slice(&credentials)
+}
+
 /// Builds a genesis state as defined by the Eth2 interop procedure (see below).
 ///
 /// Reference:
@@ -24,17 +38,67 @@ pub fn interop_genesis_state<T: EthSpec>(
     let eth1_timestamp = 2_u64.pow(40);
     let amount = spec.max_effective_balance;
 
-    let withdrawal_credentials = |pubkey: &PublicKey| {
-        let mut credentials = hash(&pubkey.as_ssz_bytes());
-        credentials[0] = spec.bls_withdrawal_prefix_byte;
-        Hash256::from_slice(&credentials)
-    };
-
     let datas = keypairs
         .into_par_iter()
         .map(|keypair| {
             let mut data = DepositData {
-                withdrawal_credentials: withdrawal_credentials(&keypair.pk),
+                withdrawal_credentials: bls_withdrawal_credentials(&keypair.pk, spec),
+                pubkey: keypair.pk.clone().into(),
+                amount,
+                signature: Signature::empty().into(),
+            };
+
+            data.signature = data.create_signature(&keypair.sk, spec);
+
+            data
+        })
+        .collect::<Vec<_>>();
+
+    let mut state = initialize_beacon_state_from_eth1(
+        eth1_block_hash,
+        eth1_timestamp,
+        genesis_deposits(datas, spec)?,
+        execution_payload_header,
+        spec,
+    )
+    .map_err(|e| format!("Unable to initialize genesis state: {:?}", e))?;
+
+    *state.genesis_time_mut() = genesis_time;
+
+    // Invalidate all the caches after all the manual state surgery.
+    state
+        .drop_all_caches()
+        .map_err(|e| format!("Unable to drop caches: {:?}", e))?;
+
+    Ok(state)
+}
+
+// returns an interop genesis state except every other
+// validator has eth1 withdrawal credentials
+pub fn interop_genesis_state_with_eth1<T: EthSpec>(
+    keypairs: &[Keypair],
+    genesis_time: u64,
+    eth1_block_hash: Hash256,
+    execution_payload_header: Option<ExecutionPayloadHeader<T>>,
+    spec: &ChainSpec,
+) -> Result<BeaconState<T>, String> {
+    let eth1_timestamp = 2_u64.pow(40);
+    let amount = spec.max_effective_balance;
+
+    let withdrawal_credentials = |index: usize, pubkey: &PublicKey| {
+        if index % 2 == 0 {
+            bls_withdrawal_credentials(pubkey, spec)
+        } else {
+            eth1_withdrawal_credentials(pubkey, spec)
+        }
+    };
+
+    let datas = keypairs
+        .into_par_iter()
+        .enumerate()
+        .map(|(index, keypair)| {
+            let mut data = DepositData {
+                withdrawal_credentials: withdrawal_credentials(index, &keypair.pk),
                 pubkey: keypair.pk.clone().into(),
                 amount,
                 signature: Signature::empty().into(),
@@ -133,4 +197,83 @@ mod test {
             "validator count should be correct"
         );
     }
+
+    #[test]
+    fn interop_state_with_eth1() {
+        let validator_count = 16;
+        let genesis_time = 42;
+        let spec = &TestEthSpec::default_spec();
+
+        let keypairs = generate_deterministic_keypairs(validator_count);
+
+        let state = interop_genesis_state_with_eth1::<TestEthSpec>(
+            &keypairs,
+            genesis_time,
+            Hash256::from_slice(DEFAULT_ETH1_BLOCK_HASH),
+            None,
+            spec,
+        )
+        .expect("should build state");
+
+        assert_eq!(
+            state.eth1_data().block_hash,
+            Hash256::from_slice(&[0x42; 32]),
+            "eth1 block hash should be co-ordinated junk"
+        );
+
+        assert_eq!(
+            state.genesis_time(),
+            genesis_time,
+            "genesis time should be as specified"
+        );
+
+        for b in state.balances() {
+            assert_eq!(
+                *b, spec.max_effective_balance,
+                "validator balances should be max effective balance"
+            );
+        }
+
+        for (index, v) in state.validators().iter().enumerate() {
+            let creds = v.withdrawal_credentials.as_bytes();
+            if index % 2 == 0 {
+                assert_eq!(
+                    creds[0], spec.bls_withdrawal_prefix_byte,
+                    "first byte of withdrawal creds should be bls prefix"
+                );
+                assert_eq!(
+                    &creds[1..],
+                    &hash(&v.pubkey.as_ssz_bytes())[1..],
+                    "rest of withdrawal creds should be pubkey hash"
+                );
+            } else {
+                assert_eq!(
+                    creds[0], spec.eth1_address_withdrawal_prefix_byte,
+                    "first byte of withdrawal creds should be eth1 prefix"
+                );
+                assert_eq!(
+                    creds[1..12],
+                    [0u8; 11],
+                    "bytes [1:12] of withdrawal creds must be zero"
+                );
+                assert_eq!(
+                    &creds[12..],
+                    &hash(&v.pubkey.as_ssz_bytes())[0..20],
+                    "rest of withdrawal creds should be first 20 bytes of pubkey hash"
+                )
+            }
+        }
+
+        assert_eq!(
+            state.balances().len(),
+            validator_count,
+            "validator balances len should be correct"
+        );
+
+        assert_eq!(
+            state.validators().len(),
+            validator_count,
+            "validator count should be correct"
+        );
+    }
 }

beacon_node/genesis/src/lib.rs

@@ -5,5 +5,7 @@ mod interop;
 pub use eth1::Config as Eth1Config;
 pub use eth1::Eth1Endpoint;
 pub use eth1_genesis_service::{Eth1GenesisService, Statistics};
-pub use interop::{interop_genesis_state, DEFAULT_ETH1_BLOCK_HASH};
+pub use interop::{
+    interop_genesis_state, interop_genesis_state_with_eth1, DEFAULT_ETH1_BLOCK_HASH,
+};
 pub use types::test_utils::generate_deterministic_keypairs;