consensus spec v1.4.0 attestation stability subnets (#5092)

AllTests-mainnet.md

@@ -258,10 +258,11 @@ OK: 1/1 Fail: 0/1 Skip: 0/1
 + General pubsub topics                                                                      OK
 + Liveness failsafe conditions                                                               OK
 + Mainnet attestation topics                                                                 OK
++ Stability subnets                                                                          OK
 + isNearSyncCommitteePeriod                                                                  OK
 + is_aggregator                                                                              OK
 ```
-OK: 5/5 Fail: 0/5 Skip: 0/5
+OK: 6/6 Fail: 0/6 Skip: 0/6
 ## ImportKeystores requests [Beacon Node] [Preset: mainnet]
 ```diff
 + ImportKeystores/ListKeystores/DeleteKeystores [Beacon Node] [Preset: mainnet]              OK
@@ -691,4 +692,4 @@ OK: 2/2 Fail: 0/2 Skip: 0/2
 OK: 9/9 Fail: 0/9 Skip: 0/9
 
 ---TOTAL---
-OK: 392/397 Fail: 0/397 Skip: 5/397
+OK: 393/398 Fail: 0/398 Skip: 5/398

beacon_chain/networking/eth2_network.nim

@@ -341,7 +341,7 @@ func shortProtocolId(protocolId: string): string =
 proc openStream(node: Eth2Node,
                 peer: Peer,
                 protocolId: string): Future[Connection] {.async.} =
-  # When dialling here, we do not provide addresses - all new connection
+  # When dialing here, we do not provide addresses - all new connection
   # attempts are handled via `connect` which also takes into account
   # reconnection timeouts
   let
@@ -354,6 +354,10 @@ proc init(T: type Peer, network: Eth2Node, peerId: PeerId): Peer {.gcsafe.}
 func peerId*(node: Eth2Node): PeerId =
   node.switch.peerInfo.peerId
 
+func nodeId*(node: Eth2Node): NodeId =
+  # `secp256k1` keys are always stored inside PeerId.
+  toNodeId(keys.PublicKey(node.switch.peerInfo.publicKey.skkey))
+
 func enrRecord*(node: Eth2Node): Record =
   node.discovery.localNode.record
 

beacon_chain/rpc/rest_config_api.nim

@@ -253,8 +253,7 @@ proc installConfigApiHandlers*(router: var RestRouter, node: BeaconNode) =
           # https://github.com/ethereum/consensus-specs/blob/v1.3.0/specs/phase0/validator.md#constants
           TARGET_AGGREGATORS_PER_COMMITTEE:
             Base10.toString(TARGET_AGGREGATORS_PER_COMMITTEE),
-          RANDOM_SUBNETS_PER_VALIDATOR:
+          RANDOM_SUBNETS_PER_VALIDATOR: "1",
-            Base10.toString(RANDOM_SUBNETS_PER_VALIDATOR),
           EPOCHS_PER_RANDOM_SUBNET_SUBSCRIPTION:
             Base10.toString(EPOCHS_PER_RANDOM_SUBNET_SUBSCRIPTION),
           ATTESTATION_SUBNET_COUNT:

beacon_chain/spec/datatypes/constants.nim

@@ -15,6 +15,21 @@ type
 
   DomainType* = distinct array[4, byte]
 
+const
+  # https://github.com/ethereum/consensus-specs/blob/v1.4.0-alpha.3/specs/phase0/p2p-interface.md#constants
+  NODE_ID_BITS* = 256
+
+  # https://github.com/ethereum/consensus-specs/blob/v1.4.0-alpha.3/specs/phase0/p2p-interface.md#configuration
+  EPOCHS_PER_SUBNET_SUBSCRIPTION* = 256
+  SUBNETS_PER_NODE* = 2'u64
+  ATTESTATION_SUBNET_COUNT*: uint64 = 64
+  ATTESTATION_SUBNET_EXTRA_BITS* = 0
+  ATTESTATION_SUBNET_PREFIX_BITS* = 6 ## \
+    ## int(ceillog2(ATTESTATION_SUBNET_COUNT) + ATTESTATION_SUBNET_EXTRA_BITS)
+
+static: doAssert 1 shl (ATTESTATION_SUBNET_PREFIX_BITS - ATTESTATION_SUBNET_EXTRA_BITS) ==
+  ATTESTATION_SUBNET_COUNT
+
 const
   # 2^64 - 1 in spec
   FAR_FUTURE_SLOT* = Slot(not 0'u64)
@@ -39,14 +54,11 @@ const
   # https://github.com/ethereum/consensus-specs/blob/v1.4.0-alpha.3/specs/capella/beacon-chain.md#domain-types
   DOMAIN_BLS_TO_EXECUTION_CHANGE* = DomainType([byte 0x0a, 0x00, 0x00, 0x00])
 
-  # https://github.com/ethereum/consensus-specs/blob/v1.3.0/specs/deneb/beacon-chain.md#domain-types
+  # https://github.com/ethereum/consensus-specs/blob/v1.4.0-alpha.3/specs/deneb/beacon-chain.md#domain-types
   DOMAIN_BLOB_SIDECAR* = DomainType([byte 0x0b, 0x00, 0x00, 0x00])
 
   # https://github.com/ethereum/consensus-specs/blob/v1.3.0/specs/bellatrix/beacon-chain.md#transition-settings
   TERMINAL_BLOCK_HASH_ACTIVATION_EPOCH* = FAR_FUTURE_EPOCH
 
-  # https://github.com/ethereum/consensus-specs/blob/v1.3.0/specs/phase0/fork-choice.md#configuration
+  # https://github.com/ethereum/consensus-specs/blob/v1.4.0-alpha.3/specs/phase0/fork-choice.md#configuration
   PROPOSER_SCORE_BOOST*: uint64 = 40
-
-  # https://github.com/ethereum/consensus-specs/blob/v1.4.0-alpha.3/specs/phase0/p2p-interface.md#configuration
-  ATTESTATION_SUBNET_COUNT*: uint64 = 64

beacon_chain/spec/validator.nim

@@ -470,3 +470,30 @@ func livenessFailsafeInEffect*(
       streakLen = 0
 
   false
+
+# https://github.com/ethereum/consensus-specs/blob/v1.4.0-alpha.3/specs/phase0/p2p-interface.md#attestation-subnet-subcription
+func compute_subscribed_subnet(node_id: UInt256, epoch: Epoch, index: uint64):
+    SubnetId =
+  # Ensure neither `truncate` loses information
+  static:
+    doAssert EPOCHS_PER_SUBNET_SUBSCRIPTION <= high(uint64)
+    doAssert sizeof(UInt256) * 8 == NODE_ID_BITS
+    doAssert ATTESTATION_SUBNET_PREFIX_BITS < sizeof(SubnetId) * 8
+
+  let
+    node_id_prefix = truncate(
+      node_id shr (NODE_ID_BITS - ATTESTATION_SUBNET_PREFIX_BITS), uint64)
+    node_offset = truncate(node_id mod EPOCHS_PER_SUBNET_SUBSCRIPTION, uint64)
+    permutation_seed = eth2digest(uint_to_bytes(
+      uint64((epoch + node_offset) div EPOCHS_PER_SUBNET_SUBSCRIPTION)))
+    permutated_prefix = compute_shuffled_index(
+      node_id_prefix,
+      1 shl ATTESTATION_SUBNET_PREFIX_BITS,
+      permutation_seed,
+    )
+  SubnetId((permutated_prefix + index) mod ATTESTATION_SUBNET_COUNT)
+
+# https://github.com/ethereum/consensus-specs/blob/v1.4.0-alpha.3/specs/phase0/p2p-interface.md#attestation-subnet-subcription
+iterator compute_subscribed_subnets*(node_id: UInt256, epoch: Epoch): SubnetId =
+  for index in 0'u64 ..< SUBNETS_PER_NODE:
+    yield compute_subscribed_subnet(node_id, epoch, index)

tests/test_honest_validator.nim

@@ -1,5 +1,5 @@
 # beacon_chain
-# Copyright (c) 2020-2022 Status Research & Development GmbH
+# Copyright (c) 2020-2023 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).
@@ -13,6 +13,8 @@ import
   ../beacon_chain/spec/[network, validator],
   ../beacon_chain/spec/datatypes/[base, altair]
 
+from std/sequtils import toSeq
+
 suite "Honest validator":
   var forkDigest: ForkDigest
 
@@ -283,3 +285,20 @@ suite "Honest validator":
         SLOTS_PER_HISTORICAL_ROOT ..
         SLOTS_PER_HISTORICAL_ROOT + FAULT_INSPECTION_WINDOW:
       check: livenessFailsafeInEffect(x, i.Slot)
+
+  test "Stability subnets":
+    check:
+      toSeq(compute_subscribed_subnets(default(UInt256), 0.Epoch)) ==
+        @[49.SubnetId, 50.SubnetId]
+      toSeq(compute_subscribed_subnets(default(UInt256), 1.Epoch)) ==
+        @[49.SubnetId, 50.SubnetId]
+      toSeq(compute_subscribed_subnets(default(UInt256), 2.Epoch)) ==
+        @[49.SubnetId, 50.SubnetId]
+      toSeq(compute_subscribed_subnets(default(UInt256), 2.Epoch)) ==
+        @[49.SubnetId, 50.SubnetId]
+      toSeq(compute_subscribed_subnets(default(UInt256), 200.Epoch)) ==
+        @[49.SubnetId, 50.SubnetId]
+      toSeq(compute_subscribed_subnets(default(UInt256), 300.Epoch)) ==
+        @[16.SubnetId, 17.SubnetId]
+      toSeq(compute_subscribed_subnets(default(UInt256), 400.Epoch)) ==
+        @[16.SubnetId, 17.SubnetId]