remove privkey from mock withdrawal credentials (#2936)

In tests, the private key was put into the validator deposit's withdraw
credentials so that it can be recovered later. This leads to problems
when creating the validators through other means that do not put the key
there. In general, mock private keys only depend on the validator index,
though, and because it is clear what the index of a validator is, it is
not actually needed to put the key into the credentials.

research/block_sim.nim

@@ -128,8 +128,7 @@ cli do(slots = SLOTS_PER_EPOCH * 6,
               sig =
                 get_attestation_signature(getStateField(stateData.data, fork),
                   getStateField(stateData.data, genesis_validators_root),
-                  data, hackPrivKey(
-                    getStateField(stateData.data, validators)[validatorIdx]))
+                  data, MockPrivKeys[validatorIdx])
             var aggregation_bits = CommitteeValidatorsBits.init(committee.len)
             aggregation_bits.setBit index_in_committee
 
@@ -165,7 +164,7 @@ cli do(slots = SLOTS_PER_EPOCH * 6,
 
         let
           validatorIdx = validatorKeyToIndex[valKey]
-          validarorPrivKey = makeFakeValidatorPrivKey(validatorIdx)
+          validarorPrivKey = MockPrivKeys[validatorIdx.ValidatorIndex]
           signature = blsSign(validarorPrivKey, signingRoot.data)
           msg = SyncCommitteeMessage(
             slot: slot,
@@ -210,7 +209,8 @@ cli do(slots = SLOTS_PER_EPOCH * 6,
           signingRoot = contribution_and_proof_signing_root(
             fork, genesisValidatorsRoot, contributionAndProof)
 
-          validarorPrivKey = makeFakeValidatorPrivKey(aggregator.validatorIdx)
+          validarorPrivKey = 
+            MockPrivKeys[aggregator.validatorIdx.ValidatorIndex]
 
           signedContributionAndProof = SignedContributionAndProof(
             message: contributionAndProof,
@@ -230,8 +230,7 @@ cli do(slots = SLOTS_PER_EPOCH * 6,
       finalizedEpochRef = dag.getFinalizedEpochRef()
       proposerIdx = get_beacon_proposer_index(
         stateData.data, cache, getStateField(stateData.data, slot)).get()
-      privKey = hackPrivKey(
-        getStateField(stateData.data, validators)[proposerIdx])
+      privKey = MockPrivKeys[proposerIdx]
       eth1ProposalData = eth1Chain.getBlockProposalData(
         stateData.data,
         finalizedEpochRef.eth1_data,

tests/test_gossip_validation.nim

@@ -218,7 +218,7 @@ suite "Gossip validation - Extra": # Not based on preset config
         state[].data.validators.mapIt(it.pubkey).find(pubKey))
       validator = AttachedValidator(
         pubKey: pubkey,
-        kind: inProcess, privKey: hackPrivKey(state[].data.validators[index]),
+        kind: inProcess, privKey: MockPrivKeys[index],
         index: some(index))
       msg = waitFor signSyncCommitteeMessage(
         validator, state[].data.slot,

tests/test_sync_committee_pool.nim

@@ -47,10 +47,10 @@ suite "Sync committee pool":
       fork = altairFork(defaultRuntimeConfig)
       genesisValidatorsRoot = eth2digest(@[5.byte, 6, 7])
 
-      privkey1 = makeFakeValidatorPrivKey(1)
-      privkey2 = makeFakeValidatorPrivKey(2)
-      privkey3 = makeFakeValidatorPrivKey(3)
-      privkey4 = makeFakeValidatorPrivKey(4)
+      privkey1 = MockPrivKeys[1.ValidatorIndex]
+      privkey2 = MockPrivKeys[2.ValidatorIndex]
+      privkey3 = MockPrivKeys[3.ValidatorIndex]
+      privkey4 = MockPrivKeys[4.ValidatorIndex]
 
       root1 = eth2digest(@[1.byte])
       root2 = eth2digest(@[1.byte, 2])

tests/testblockutil.nim

@@ -10,7 +10,7 @@ import
   options, stew/endians2,
   ../beacon_chain/validators/validator_pool,
   ../beacon_chain/spec/datatypes/merge,
-  ../beacon_chain/spec/[helpers, signatures, state_transition, forks]
+  ../beacon_chain/spec/[helpers, keystore, signatures, state_transition, forks]
 
 type
   MockPrivKeysT = object
@@ -30,35 +30,22 @@ func `[]`*(_: MockPrivKeysT, index: ValidatorIndex): ValidatorPrivKey =
 func `[]`*(_: MockPubKeysT, index: ValidatorIndex): ValidatorPubKey =
   MockPrivKeys[index].toPubKey().toPubKey()
 
-func makeFakeValidatorPrivKey*(i: int): ValidatorPrivKey =
-  MockPrivKeys[i.ValidatorIndex]
-
 func makeFakeHash*(i: int): Eth2Digest =
   var bytes = uint64(i).toBytesLE()
   static: doAssert sizeof(bytes) <= sizeof(result.data)
   copyMem(addr result.data[0], addr bytes[0], sizeof(bytes))
 
-func hackPrivKey*(v: Validator): ValidatorPrivKey =
-  ## Extract private key, per above hack
-  var bytes: array[8, byte]
-  static: doAssert sizeof(bytes) <= sizeof(v.withdrawal_credentials.data)
-
-  copyMem(
-    addr bytes, unsafeAddr v.withdrawal_credentials.data[0], sizeof(bytes))
-  let i = int(uint64.fromBytesLE(bytes))
-  makeFakeValidatorPrivKey(i)
-
-func makeDeposit*(i: int, flags: UpdateFlags = {}, cfg = defaultRuntimeConfig): DepositData =
-  ## Ugly hack for now: we stick the private key in withdrawal_credentials
-  ## which means we can repro private key and randao reveal from this data,
-  ## for testing :)
+func makeDeposit*(
+    i: int, 
+    flags: UpdateFlags = {}, 
+    cfg = defaultRuntimeConfig): DepositData =
   let
-    privkey = makeFakeValidatorPrivKey(i)
-    pubkey = privkey.toPubKey()
-    withdrawal_credentials = makeFakeHash(i)
+    privkey = MockPrivKeys[i.ValidatorIndex]
+    pubkey = MockPubKeys[i.ValidatorIndex]
+    withdrawal_credentials = makeWithdrawalCredentials(pubkey)
 
   result = DepositData(
-    pubkey: pubkey.toPubKey(),
+    pubkey: pubkey,
     withdrawal_credentials: withdrawal_credentials,
     amount: MAX_EFFECTIVE_BALANCE)
 
@@ -104,7 +91,7 @@ proc addTestBlock*(
   let
     proposer_index = get_beacon_proposer_index(
       state, cache, getStateField(state, slot))
-    privKey = hackPrivKey(getStateField(state, validators)[proposer_index.get])
+    privKey = MockPrivKeys[proposer_index.get]
     randao_reveal =
       if skipBlsValidation notin flags:
         privKey.genRandaoReveal(
@@ -221,7 +208,7 @@ func makeAttestation*(
         get_attestation_signature(
           getStateField(state, fork),
           getStateField(state, genesis_validators_root),
-          data, hackPrivKey(validator)).toValidatorSig()
+          data, MockPrivKeys[validator_index]).toValidatorSig()
       else:
         ValidatorSig()
 
@@ -280,7 +267,7 @@ func makeFullAttestations*(
     agg.init(get_attestation_signature(
         getStateField(state, fork),
         getStateField(state, genesis_validators_root), data,
-        hackPrivKey(getStateField(state, validators)[committee[0]])))
+        MockPrivKeys[committee[0]]))
 
     # Aggregate the remainder
     attestation.aggregation_bits.setBit 0
@@ -290,7 +277,7 @@ func makeFullAttestations*(
         agg.aggregate(get_attestation_signature(
           getStateField(state, fork),
           getStateField(state, genesis_validators_root), data,
-          hackPrivKey(getStateField(state, validators)[committee[j]])
+          MockPrivKeys[committee[j]]
         ))
 
     attestation.signature = agg.finish().toValidatorSig()