Add historical_roots with proof + test (#1579)

fluffy/network/history/experimental/beacon_chain_historical_roots.nim

@@ -7,10 +7,16 @@
 
 #
 # Example of how the beacon state historical_roots field could be provided with
-# a Merkle proof that can be verified against the right state root.
+# a Merkle proof that can be verified against the right beacon state root.
 # These historical_roots with their proof could for example be provided over the
 # network and verified on the receivers end.
 #
+# Note:
+# Since Capella the historical_roots field is frozen. Thus providing the
+# historical_roots with a Proof against the latest state seems a bit silly.
+# One idea could be to embed it into the client just as is done for the
+# execution header accumulator.
+#
 
 {.push raises: [].}
 

fluffy/network/history/experimental/beacon_chain_historical_summaries.nim

@@ -0,0 +1,49 @@
+# Nimbus
+# Copyright (c) 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).
+# at your option. This file may not be copied, modified, or distributed except according to those terms.
+
+#
+# Example of how the beacon state historical_summaries field could be provided
+# with a Merkle proof that can be verified against the right beacon state root.
+# These historical_summaries with their proof could for example be provided over
+# the network and verified on the receivers end.
+#
+
+{.push raises: [].}
+
+import
+  stew/results,
+  beacon_chain/spec/forks,
+  beacon_chain/spec/datatypes/capella
+
+export results
+
+type
+  HistoricalSummaries* = HashList[HistoricalSummary, Limit HISTORICAL_ROOTS_LIMIT]
+  HistoricalSummariesProof* = array[5, Digest]
+  HistoricalSummariesWithProof* = object
+    historical_summaries: HistoricalSummaries
+    proof: HistoricalSummariesProof
+
+func buildProof*(
+    state: ForkedHashedBeaconState): Result[HistoricalSummariesProof, string] =
+  let gIndex = GeneralizedIndex(59) # 31 + 28 = 59
+
+  var proof: HistoricalSummariesProof
+  withState(state):
+    ? forkyState.data.build_proof(gIndex, proof)
+
+  ok(proof)
+
+func verifyProof*(
+    historical_summaries: HistoricalSummaries,
+    proof: HistoricalSummariesProof,
+    stateRoot: Digest): bool =
+  let
+    gIndex = GeneralizedIndex(59)
+    leave = hash_tree_root(historical_summaries)
+
+  verify_merkle_multiproof(@[leave], proof, @[gIndex], stateRoot)

fluffy/tests/all_fluffy_tests.nim

@@ -17,4 +17,5 @@ import
   ./test_content_db,
   ./test_discovery_rpc,
   ./test_beacon_chain_block_proof,
-  ./test_beacon_chain_historical_roots
+  ./test_beacon_chain_historical_roots,
+  ./test_beacon_chain_historical_summaries

fluffy/tests/test_beacon_chain_historical_roots.nim

@@ -13,19 +13,16 @@ import
   unittest2,
   beacon_chain/spec/forks,
   beacon_chain/spec/datatypes/bellatrix,
+  # Test helpers
   beacon_chain/../tests/testblockutil,
-  # Mock helpers
   beacon_chain/../tests/mocking/mock_genesis,
+  beacon_chain/../tests/consensus_spec/fixtures_utils,
 
   ../network/history/experimental/beacon_chain_historical_roots
 
 suite "Beacon Chain Historical Roots":
   let
-    cfg = block:
-      var res = defaultRuntimeConfig
-      res.ALTAIR_FORK_EPOCH = GENESIS_EPOCH
-      res.BELLATRIX_FORK_EPOCH = GENESIS_EPOCH
-      res
+    cfg = genesisTestRuntimeConfig(ConsensusFork.Bellatrix)
     state = newClone(initGenesisState(cfg = cfg))
   var cache = StateCache()
 

fluffy/tests/test_beacon_chain_historical_summaries.nim

@@ -0,0 +1,49 @@
+# Nimbus
+# Copyright (c) 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).
+# at your option. This file may not be copied, modified, or distributed except according to those terms.
+
+{.used.}
+
+{.push raises: [].}
+
+import
+  unittest2,
+  beacon_chain/spec/forks,
+  beacon_chain/spec/datatypes/capella,
+  # Test helpers
+  beacon_chain/../tests/testblockutil,
+  beacon_chain/../tests/mocking/mock_genesis,
+  beacon_chain/../tests/consensus_spec/fixtures_utils,
+
+  ../network/history/experimental/beacon_chain_historical_summaries
+
+suite "Beacon Chain Historical Summaries":
+  let
+    cfg = genesisTestRuntimeConfig(ConsensusFork.Capella)
+    state = newClone(initGenesisState(cfg = cfg))
+  var cache = StateCache()
+
+  var blocks: seq[capella.SignedBeaconBlock]
+  # Note:
+  # Adding 8192 blocks. First block is genesis block and not one of these.
+  # Then one extra block is needed to get the historical summaries, block
+  # roots and state roots processed.
+  # index i = 0 is second block.
+  # index i = 8190 is 8192th block and last one that is part of the first
+  # historical root
+  for i in 0..<SLOTS_PER_HISTORICAL_ROOT:
+    blocks.add(addTestBlock(state[], cache, cfg = cfg).capellaData)
+
+  test "Historical Summaries Proof":
+    withState(state[]):
+      when consensusFork >= ConsensusFork.Capella:
+        let historical_summaries = forkyState.data.historical_summaries
+        let res = buildProof(state[])
+        check res.isOk()
+        let proof = res.get()
+
+        withState(state[]):
+          check verifyProof(historical_summaries, proof, forkyState.root)