require sync committee supermajority in CI (#5085)

* require sync committee supermajority in CI

To better catch problems with sync committee messages in CI, extend
local testnet simulation to also verify that each block is signed
by a supermajority of the sync committee.

Requires #5083 and #5084

* lint

beacon_chain/spec/state_transition_block.nim

@@ -465,8 +465,17 @@ proc process_sync_aggregate*(
     state: var (altair.BeaconState | bellatrix.BeaconState |
                 capella.BeaconState | deneb.BeaconState),
     sync_aggregate: SomeSyncAggregate, total_active_balance: Gwei,
+    flags: UpdateFlags,
     cache: var StateCache):
     Result[void, cstring]  =
+  if strictVerification in flags and state.slot > 1.Slot:
+    template sync_committee_bits(): auto = sync_aggregate.sync_committee_bits
+    let num_active_participants = countOnes(sync_committee_bits).uint64
+    if num_active_participants * 3 < static(sync_committee_bits.len * 2):
+      fatal "Low sync committee participation",
+        slot = state.slot, num_active_participants
+      quit 1
+
   # Verify sync committee aggregate signature signing over the previous slot
   # block root
   when sync_aggregate.sync_committee_signature isnot TrustedSig:
@@ -822,7 +831,8 @@ proc process_block*(
   ? process_operations(
     cfg, state, blck.body, base_reward_per_increment, flags, cache)
   ? process_sync_aggregate(
-    state, blck.body.sync_aggregate, total_active_balance, cache)  # [New in Altair]
+    state, blck.body.sync_aggregate, total_active_balance,
+    flags, cache)  # [New in Altair]
 
   ok()
 
@@ -853,7 +863,7 @@ proc process_block*(
   ? process_operations(
     cfg, state, blck.body, base_reward_per_increment, flags, cache)
   ? process_sync_aggregate(
-    state, blck.body.sync_aggregate, total_active_balance, cache)
+    state, blck.body.sync_aggregate, total_active_balance, flags, cache)
 
   ok()
 
@@ -890,7 +900,7 @@ proc process_block*(
     cfg, state, blck.body, base_reward_per_increment,
     flags, cache)  # [Modified in Capella]
   ? process_sync_aggregate(
-    state, blck.body.sync_aggregate, total_active_balance, cache)
+    state, blck.body.sync_aggregate, total_active_balance, flags, cache)
 
   ok()
 
@@ -925,6 +935,6 @@ proc process_block*(
   ? process_operations(
     cfg, state, blck.body, base_reward_per_increment, flags, cache)
   ? process_sync_aggregate(
-    state, blck.body.sync_aggregate, total_active_balance, cache)
+    state, blck.body.sync_aggregate, total_active_balance, flags, cache)
 
   ok()

tests/consensus_spec/altair/test_fixture_operations.nim

@@ -1,5 +1,5 @@
 # beacon_chain
-# Copyright (c) 2018-2022 Status Research & Development GmbH
+# Copyright (c) 2018-2023 Status Research & Development GmbH
 # Licensed and distributed under either of
 #   * MIT license (license terms in the root directory or at https://opensource.org/licenses/MIT).
 #   * Apache v2 license (license terms in the root directory or at https://www.apache.org/licenses/LICENSE-2.0).
@@ -140,7 +140,8 @@ suite baseDescription & "Sync Aggregate " & preset():
       Result[void, cstring] =
     var cache = StateCache()
     process_sync_aggregate(
-      preState, syncAggregate, get_total_active_balance(preState, cache), cache)
+      preState, syncAggregate, get_total_active_balance(preState, cache),
+      {}, cache)
 
   for path in walkTests(OpSyncAggregateDir):
     runTest[SyncAggregate, typeof applySyncAggregate](

tests/consensus_spec/bellatrix/test_fixture_operations.nim

@@ -161,7 +161,8 @@ suite baseDescription & "Sync Aggregate " & preset():
       Result[void, cstring] =
     var cache = StateCache()
     process_sync_aggregate(
-      preState, syncAggregate, get_total_active_balance(preState, cache), cache)
+      preState, syncAggregate, get_total_active_balance(preState, cache),
+      {}, cache)
 
   for path in walkTests(OpSyncAggregateDir):
     runTest[SyncAggregate, typeof applySyncAggregate](

tests/consensus_spec/capella/test_fixture_operations.nim

@@ -178,7 +178,8 @@ suite baseDescription & "Sync Aggregate " & preset():
       Result[void, cstring] =
     var cache = StateCache()
     process_sync_aggregate(
-      preState, syncAggregate, get_total_active_balance(preState, cache), cache)
+      preState, syncAggregate, get_total_active_balance(preState, cache),
+      {}, cache)
 
   for path in walkTests(OpSyncAggregateDir):
     runTest[SyncAggregate, typeof applySyncAggregate](

tests/consensus_spec/deneb/test_fixture_operations.nim

@@ -180,7 +180,8 @@ suite baseDescription & "Sync Aggregate " & preset():
       Result[void, cstring] =
     var cache = StateCache()
     process_sync_aggregate(
-      preState, syncAggregate, get_total_active_balance(preState, cache), cache)
+      preState, syncAggregate, get_total_active_balance(preState, cache),
+      {}, cache)
 
   for path in walkTests(OpSyncAggregateDir):
     runTest[SyncAggregate, typeof applySyncAggregate](