fix Electra light client objects; use version-2-0 for Nim again (#6222)

Author: tersec

.github/workflows/ci.yml

@@ -33,7 +33,7 @@ jobs:
             cpu: amd64
           - os: windows
             cpu: amd64
-        branch: [~, upstream/version-1-6, v2.0.4]
+        branch: [~, upstream/version-1-6, upstream/version-2-0]
         exclude:
           - target:
               os: macos
@@ -47,7 +47,7 @@ jobs:
         include:
           - branch: upstream/version-1-6
             branch-short: version-1-6
-          - branch: v2.0.4
+          - branch: upstream/version-2-0
             branch-short: version-2-0
             nimflags-extra: --mm:refc
           - target:

beacon_chain/spec/datatypes/electra.nim

@@ -18,18 +18,36 @@
 import
   std/typetraits,
   chronicles,
-  stew/byteutils,
   json_serialization,
   ssz_serialization/[merkleization, proofs],
   ssz_serialization/types as sszTypes,
   ../digest,
-  "."/[base, phase0, altair, bellatrix, capella]
+  "."/[base, phase0]
 
 from kzg4844 import KzgCommitment, KzgProof
+from stew/bitops2 import log2trunc
+from stew/byteutils import to0xHex
+from ./altair import
+  EpochParticipationFlags, InactivityScores, SyncAggregate, SyncCommittee,
+  TrustedSyncAggregate
+from ./bellatrix import BloomLogs, ExecutionAddress, Transaction
+from ./capella import
+  HistoricalSummary, SignedBLSToExecutionChangeList, Withdrawal
 from ./deneb import Blobs, BlobsBundle, KzgCommitments, KzgProofs
 
 export json_serialization, base, kzg4844
 
+const
+  # https://github.com/ethereum/consensus-specs/blob/v1.4.0-beta.5/specs/altair/light-client/sync-protocol.md#constants
+  # All of these indices are rooted in `BeaconState`.
+  # The first member (`genesis_time`) is 64, subsequent members +1 each.
+  # If there are ever more than 64 members in `BeaconState`, indices change!
+  # `FINALIZED_ROOT_GINDEX` is one layer deeper, i.e., `84 * 2 + 1`.
+  # https://github.com/ethereum/consensus-specs/blob/v1.4.0/ssz/merkle-proofs.md
+  FINALIZED_ROOT_GINDEX = 169.GeneralizedIndex  # finalized_checkpoint > root
+  CURRENT_SYNC_COMMITTEE_GINDEX = 86.GeneralizedIndex  # current_sync_committee
+  NEXT_SYNC_COMMITTEE_GINDEX = 87.GeneralizedIndex  # next_sync_committee
+
 type
   # https://github.com/ethereum/consensus-specs/blob/94a0b6c581f2809aa8aca4ef7ee6fbb63f9d74e9/specs/electra/beacon-chain.md#depositreceipt
   DepositReceipt* = object
@@ -75,7 +93,7 @@ type
     blockValue*: Wei
     blobsBundle*: BlobsBundle
 
-  # https://github.com/ethereum/consensus-specs/blob/82133085a1295e93394ebdf71df8f2f6e0962588/specs/electra/beacon-chain.md#executionpayloadheader
+  # https://github.com/ethereum/consensus-specs/blob/v1.5.0-alpha.0/specs/electra/beacon-chain.md#executionpayloadheader
   ExecutionPayloadHeader* = object
     # Execution block header fields
     parent_hash*: Eth2Digest
@@ -141,12 +159,21 @@ type
     source_index*: uint64
     target_index*: uint64
 
+  FinalityBranch =
+    array[log2trunc(FINALIZED_ROOT_GINDEX), Eth2Digest]
+
+  CurrentSyncCommitteeBranch =
+    array[log2trunc(CURRENT_SYNC_COMMITTEE_GINDEX), Eth2Digest]
+
+  NextSyncCommitteeBranch =
+    array[log2trunc(NEXT_SYNC_COMMITTEE_GINDEX), Eth2Digest]
+
   # https://github.com/ethereum/consensus-specs/blob/v1.4.0-beta.5/specs/capella/light-client/sync-protocol.md#modified-lightclientheader
   LightClientHeader* = object
     beacon*: BeaconBlockHeader
       ## Beacon block header
 
-    execution*: ExecutionPayloadHeader
+    execution*: electra.ExecutionPayloadHeader
       ## Execution payload header corresponding to `beacon.body_root` (from Capella onward)
     execution_branch*: capella.ExecutionBranch
 
@@ -157,7 +184,7 @@ type
 
     current_sync_committee*: SyncCommittee
       ## Current sync committee corresponding to `header.beacon.state_root`
-    current_sync_committee_branch*: altair.CurrentSyncCommitteeBranch
+    current_sync_committee_branch*: CurrentSyncCommitteeBranch
 
   # https://github.com/ethereum/consensus-specs/blob/v1.4.0-beta.5/specs/altair/light-client/sync-protocol.md#lightclientupdate
   LightClientUpdate* = object
@@ -167,11 +194,11 @@ type
     next_sync_committee*: SyncCommittee
       ## Next sync committee corresponding to
       ## `attested_header.beacon.state_root`
-    next_sync_committee_branch*: altair.NextSyncCommitteeBranch
+    next_sync_committee_branch*: NextSyncCommitteeBranch
 
     # Finalized header corresponding to `attested_header.beacon.state_root`
     finalized_header*: LightClientHeader
-    finality_branch*: altair.FinalityBranch
+    finality_branch*: FinalityBranch
 
     sync_aggregate*: SyncAggregate
       ## Sync committee aggregate signature
@@ -185,7 +212,7 @@ type
 
     # Finalized header corresponding to `attested_header.beacon.state_root`
     finalized_header*: LightClientHeader
-    finality_branch*: altair.FinalityBranch
+    finality_branch*: FinalityBranch
 
     # Sync committee aggregate signature
     sync_aggregate*: SyncAggregate
@@ -405,7 +432,7 @@ type
     attester_slashings*:
       List[AttesterSlashing, Limit MAX_ATTESTER_SLASHINGS_ELECTRA]
       ## [Modified in Electra:EIP7549]
-    attestations*: List[Attestation, Limit MAX_ATTESTATIONS_ELECTRA]
+    attestations*: List[phase0.Attestation, Limit MAX_ATTESTATIONS_ELECTRA]
       ## [Modified in Electra:EIP7549]
     deposits*: List[Deposit, Limit MAX_DEPOSITS]
     voluntary_exits*: List[SignedVoluntaryExit, Limit MAX_VOLUNTARY_EXITS]
@@ -527,6 +554,9 @@ type
 
     root* {.dontSerialize.}: Eth2Digest # cached root of signed beacon block
 
+  ElectraCommitteeValidatorsBits* =
+    BitList[Limit MAX_VALIDATORS_PER_COMMITTEE * MAX_COMMITTEES_PER_SLOT]
+
   SomeSignedBeaconBlock* =
     SignedBeaconBlock |
     SigVerifiedSignedBeaconBlock |

beacon_chain/spec/eth2_merkleization.nim

@@ -21,6 +21,7 @@ from ./datatypes/altair import HashedBeaconState, SignedBeaconBlock
 from ./datatypes/bellatrix import HashedBeaconState, SignedBeaconBlock
 from ./datatypes/capella import HashedBeaconState, SignedBeaconBlock
 from ./datatypes/deneb import HashedBeaconState, SignedBeaconBlock
+from ./datatypes/electra import HashedBeaconState, SignedBeaconBlock
 
 export ssz_codec, merkleization, proofs
 
@@ -32,13 +33,13 @@ type
 func hash_tree_root*(
     x: phase0.HashedBeaconState | altair.HashedBeaconState |
        bellatrix.HashedBeaconState | capella.HashedBeaconState |
-       deneb.HashedBeaconState) {.
+       deneb.HashedBeaconState | electra.SignedBeaconBlock) {.
   error: "HashedBeaconState should not be hashed".}
 
 func hash_tree_root*(
     x: phase0.SignedBeaconBlock | altair.SignedBeaconBlock |
        bellatrix.SignedBeaconBlock | capella.SignedBeaconBlock |
-       deneb.SignedBeaconBlock) {.
+       deneb.SignedBeaconBlock | electra.SignedBeaconBlock) {.
   error: "SignedBeaconBlock should not be hashed".}
 
 func depositCountBytes*(x: uint64): array[32, byte] =

beacon_chain/spec/eth2_ssz_serialization.nim

@@ -17,6 +17,7 @@ import
   ./eth2_merkleization
 
 from ./datatypes/deneb import SignedBeaconBlock, TrustedSignedBeaconBlock
+from ./datatypes/electra import SignedBeaconBlock, TrustedSignedBeaconBlock
 
 export phase0, altair, ssz_codec, ssz_serialization, eth2_merkleization
 
@@ -60,6 +61,12 @@ template readSszBytes*(
 template readSszBytes*(
     data: openArray[byte], val: var deneb.TrustedSignedBeaconBlock, updateRoot = true) =
   readAndUpdateRoot(data, val, updateRoot)
+template readSszBytes*(
+    data: openArray[byte], val: var electra.SignedBeaconBlock, updateRoot = true) =
+  readAndUpdateRoot(data, val, updateRoot)
+template readSszBytes*(
+    data: openArray[byte], val: var electra.TrustedSignedBeaconBlock, updateRoot = true) =
+  readAndUpdateRoot(data, val, updateRoot)
 
 template readSszBytes*(
     data: openArray[byte], val: var auto, updateRoot: bool) =
@@ -78,4 +85,4 @@ proc fromSszBytes*(
   let
     key = ValidatorPubKey.fromSszBytes(bytes)
 
-  HashedValidatorPubKey.init(key)
+  HashedValidatorPubKey.init(key)

beacon_chain/spec/forks.nim

@@ -617,6 +617,7 @@ template PayloadAttributes*(
 static: doAssert ConsensusFork.high == ConsensusFork.Electra,
   "eth2_merkleization has been checked and `hash_tree_root` is up to date"
 
+# TODO are these used?
 # TODO when https://github.com/nim-lang/Nim/issues/21086 fixed, use return type
 # `ref T`
 func new*(T: type ForkedHashedBeaconState, data: phase0.BeaconState):

beacon_chain/sync/sync_protocol.nim

@@ -49,6 +49,7 @@ proc readChunkPayload*(
   except CatchableError:
     return neterr UnexpectedEOF
 
+  static: doAssert ConsensusFork.high == ConsensusFork.Electra
   if contextBytes == peer.network.forkDigests.phase0:
     let res = await readChunkPayload(conn, peer, phase0.SignedBeaconBlock)
     if res.isOk:
@@ -79,6 +80,12 @@ proc readChunkPayload*(
       return ok newClone(ForkedSignedBeaconBlock.init(res.get))
     else:
       return err(res.error)
+  elif contextBytes == peer.network.forkDigests.electra:
+    let res = await readChunkPayload(conn, peer, electra.SignedBeaconBlock)
+    if res.isOk:
+      return ok newClone(ForkedSignedBeaconBlock.init(res.get))
+    else:
+      return err(res.error)
   else:
     return neterr InvalidContextBytes