Add domain to all signature funcitons, modify validate_proof_of_possession()

eth2/types/src/attestation.rs

@@ -25,11 +25,10 @@ impl Attestation {
         &self,
         group_public_key: &AggregatePublicKey,
         custody_bit: bool,
-        // TODO: use domain.
-        _domain: u64,
+        domain: u64,
     ) -> bool {
         self.aggregate_signature
-            .verify(&self.signable_message(custody_bit), group_public_key)
+            .verify(&self.signable_message(custody_bit), domain, group_public_key)
     }
 }
 

eth2/types/src/beacon_state.rs

@@ -1,10 +1,9 @@
 use crate::test_utils::TestRandom;
 use crate::{
     validator::StatusFlags, validator_registry::get_active_validator_indices, AttestationData,
-    Bitfield, ChainSpec, Crosslink, Deposit, Epoch, Eth1Data, Eth1DataVote, Fork, Hash256,
+    Bitfield, ChainSpec, Crosslink, Deposit, DepositInput, Epoch, Eth1Data, Eth1DataVote, Fork, Hash256,
     PendingAttestation, PublicKey, Signature, Slot, Validator,
 };
-use bls::verify_proof_of_possession;
 use honey_badger_split::SplitExt;
 use rand::RngCore;
 use serde_derive::Serialize;
@@ -587,6 +586,32 @@ impl BeaconState {
 
         self.validator_registry_update_epoch = current_epoch;
     }
+
+    /// Confirm validator owns PublicKey
+    pub fn validate_proof_of_possession(
+        &self,
+        pubkey: PublicKey,
+        proof_of_possession: Signature,
+        withdrawal_credentials: Hash256,
+        spec: &ChainSpec
+    ) -> bool {
+        let proof_of_possession_data = DepositInput {
+            pubkey: pubkey.clone(),
+            withdrawal_credentials,
+            proof_of_possession: proof_of_possession.clone(),
+        };
+
+        proof_of_possession.verify(
+            &proof_of_possession_data.hash_tree_root(),
+            self.fork.get_domain(
+                self.slot.epoch(spec.epoch_length),
+                spec.domain_deposit,
+            ),
+            &pubkey,
+        )
+    }
+
+
     /// Process a validator deposit, returning the validator index if the deposit is valid.
     ///
     /// Spec v0.2.0
@@ -598,8 +623,7 @@ impl BeaconState {
         withdrawal_credentials: Hash256,
         spec: &ChainSpec,
     ) -> Result<usize, ()> {
-        // TODO: ensure verify proof-of-possession represents the spec accurately.
-        if !verify_proof_of_possession(&proof_of_possession, &pubkey) {
+        if !self.validate_proof_of_possession(pubkey.clone(), proof_of_possession, withdrawal_credentials, &spec) {
             return Err(());
         }
 

eth2/types/src/fork.rs

@@ -10,6 +10,22 @@ pub struct Fork {
     pub epoch: Epoch,
 }
 
+impl Fork {
+    /// Return the fork version of the given ``epoch``.
+    pub fn get_fork_version(&self, epoch: Epoch) -> u64 {
+        if epoch < self.epoch {
+            return self.previous_version;
+        }
+        self.current_version
+    }
+
+    /// Get the domain number that represents the fork meta and signature domain.
+    pub fn get_domain(&self, epoch: Epoch, domain_type: u64) -> u64 {
+        let fork_version = self.get_fork_version(epoch);
+        fork_version * u64::pow(2,32) + domain_type
+    }
+}
+
 impl Encodable for Fork {
     fn ssz_append(&self, s: &mut SszStream) {
         s.append(&self.previous_version);

eth2/types/src/test_utils/signature.rs

@@ -8,6 +8,6 @@ impl<T: RngCore> TestRandom<T> for Signature {
         let mut message = vec![0; 32];
         rng.fill_bytes(&mut message);
 
-        Signature::new(&message, &secret_key)
+        Signature::new(&message, 0, &secret_key)
     }
 }