Local slashing db (#3)

* Migrate consensus specs from a submodule to the pypi eth2specs

* Move from install script to Makefile & add linting

* All of the linting

* Move over to local slashing db & start defining own types

* Add ValidatorIdentity, fix tests, fix imports

* Revert to relative imports in src/dvspec/* module files

* Add glossary

* Update UML diagrams

* Formatting in glossary

Co-authored-by: Aditya Asgaonkar <[email protected]>

Author: CarlBeek

Makefile

@@ -25,8 +25,7 @@ venv_activate:
 	$(VENV_ACTIVATE)
 
 venv_lint: venv_activate
-	flake8 --config=flake8.ini ./src ./tests && mypy --config-file mypy.ini ./src ./tests
+	$(VENV_ACTIVATE) && flake8 --config=flake8.ini ./src ./tests && mypy --config-file mypy.ini ./src ./tests
 
 venv_test: venv_activate
 	@echo "TODO: implement tests"
-

consensus-specs

@@ -0,0 +1,12 @@
+# Glossary
+
+## Ethereum Concepts
+
+- **Validator**: A public key participating in proof-of-stake validation of Ethereum. In Phase 0, validators are expected to perform attestation & block proposal duties for beacon chain blocks.
+- **Validator Client (VC)**: Software to perform the duties of Validators. The VC has access to the private key of the Validators.
+
+## Distributed Validator Concepts
+
+- **Distributed Validator (DV)**: A group of participants collboratively performing the duties of a Validator. The Validator's private key is secret-shared among the participants so that a complete signature cannot be formed without some majority threshold of participants.
+- **Co-Validator**: A threshold BLS public key participating in the DV protocol for a *particular* Validator.
+- **Distributed Validator Client (DVC)**: Software to participate as a Co-Validator by running the DV protocol (or, to participate as multiple Co-Validators that are each associated with a different Validator). The DVC has access to the private key(s) of the Co-Validator(s), which is(are) the secret-shared threshold private key of the respective Validator(s).

figures/dv-attestation-production-process.png

@@ -1,23 +1,78 @@
-from dvspec.eth_node_interface import (
+import eth2spec.phase0.mainnet as eth2spec
+
+from .eth_node_interface import (
     AttestationData,
-    AttestationDuty,
     BeaconBlock,
+)
+from .utils.types import (
+    AttestationDuty,
+    BLSPubkey,
     ProposerDuty,
-    vc_is_slashable_attestation_data,
-    vc_is_slashable_block
+    SlashingDB,
 )
 
+"""
+Helper Functions
+"""
+
+
+def is_slashable_attestation_data(slashing_db: SlashingDB,
+                                  attestation_data: AttestationData, pubkey: BLSPubkey) -> bool:
+    matching_slashing_db_data = [data for data in slashing_db.data if data.pubkey == pubkey]
+    if matching_slashing_db_data == []:
+        return True
+    assert len(matching_slashing_db_data) == 1
+    slashing_db_data = matching_slashing_db_data[0]
+    # Check for EIP-3076 conditions:
+    # https://eips.ethereum.org/EIPS/eip-3076#conditions
+    if slashing_db_data.signed_attestations != []:
+        min_target = min(attn.target_epoch for attn in slashing_db_data.signed_attestations)
+        min_source = min(attn.source_epoch for attn in slashing_db_data.signed_attestations)
+        if attestation_data.target.epoch <= min_target:
+            return True
+        if attestation_data.source.epoch < min_source:
+            return True
+    for past_attn in slashing_db_data.signed_attestations:
+        past_attn_data = AttestationData(source=past_attn.source_epoch, target=past_attn.target_epoch)
+        if eth2spec.is_slashable_attestation_data(past_attn_data, attestation_data):
+            return True
+    return False
+
+
+def is_slashable_block(slashing_db: SlashingDB, block: BeaconBlock, pubkey: BLSPubkey) -> bool:
+    matching_slashing_db_data = [data for data in slashing_db.data if data.pubkey == pubkey]
+    if matching_slashing_db_data == []:
+        return False
+    assert len(matching_slashing_db_data) == 1
+    slashing_db_data = matching_slashing_db_data[0]
+    # Check for EIP-3076 conditions:
+    # https://eips.ethereum.org/EIPS/eip-3076#conditions
+    if slashing_db_data.signed_blocks != []:
+        min_block = slashing_db_data.signed_blocks[0]
+        for b in slashing_db_data.signed_blocks[1:]:
+            if b.slot < min_block.slot:
+                min_block = b
+        if block.slot < min_block.slot:
+            return True
+    for past_block in slashing_db_data.signed_blocks:
+        if past_block.slot == block.slot:
+            if past_block.signing_root() != block.hash_tree_root():
+                return True
+    return False
+
+
 """
 Consensus Specification
 """
 
 
-def consensus_is_valid_attestation_data(attestation_data: AttestationData, attestation_duty: AttestationDuty) -> bool:
+def consensus_is_valid_attestation_data(slashing_db: SlashingDB,
+                                        attestation_data: AttestationData, attestation_duty: AttestationDuty) -> bool:
     """Determines if the given attestation is valid for the attestation duty.
     """
     assert attestation_data.slot == attestation_duty.slot
     assert attestation_data.committee_index == attestation_duty.committee_index
-    assert not vc_is_slashable_attestation_data(attestation_data, attestation_duty.pubkey)
+    assert not is_slashable_attestation_data(slashing_db, attestation_data, attestation_duty.pubkey)
     return True
 
 
@@ -30,12 +85,12 @@ def consensus_on_attestation(attestation_duty: AttestationDuty) -> AttestationDa
     pass
 
 
-def consensus_is_valid_block(block: BeaconBlock, proposer_duty: ProposerDuty) -> bool:
+def consensus_is_valid_block(slashing_db: SlashingDB, block: BeaconBlock, proposer_duty: ProposerDuty) -> bool:
     """Determines if the given block is valid for the proposer duty.
     """
     assert block.slot == proposer_duty.slot
     # TODO: Assert correct block.proposer_index
-    assert not vc_is_slashable_block(block, proposer_duty.pubkey)
+    assert not is_slashable_block(slashing_db, block, proposer_duty.pubkey)
     return True
 
 

figures/dv-block-production-process.png

@@ -3,35 +3,21 @@
     Attestation,
     AttestationData,
     BeaconBlock,
-    BLSPubkey,
+    SignedBeaconBlock,
+)
+
+from .utils.types import (
+    AttestationDuty,
     BLSSignature,
     Bytes32,
     CommitteeIndex,
-    Container,
     Epoch,
-    SignedBeaconBlock,
+    ProposerDuty,
     Slot,
-    uint64,
     ValidatorIndex,
 )
 
 
-class AttestationDuty(Container):
-    pubkey: BLSPubkey
-    validator_index: ValidatorIndex
-    committee_index: CommitteeIndex
-    committee_length: uint64
-    committees_at_slot: uint64
-    validator_committee_index: ValidatorIndex  # TODO: Is this the correct datatype?
-    slot: Slot
-
-
-class ProposerDuty(Container):
-    pubkey: BLSPubkey
-    validator_index: ValidatorIndex
-    slot: Slot
-
-
 # Beacon Node Interface
 
 def bn_get_attestation_duties_for_epoch(validator_indices: List[ValidatorIndex], epoch: Epoch) -> List[AttestationDuty]:
@@ -80,12 +66,6 @@ def bn_submit_block(block: SignedBeaconBlock) -> None:
 
 # Validator Client Interface
 
-def vc_is_slashable_attestation_data(attestation_data: AttestationData, validator_pubkey: BLSPubkey) -> bool:
-    """Checks whether the attestation data is slashable according to the anti-slashing database.
-    This endpoint does not exist in beacon-APIs.
-    """
-    pass
-
 
 def vc_sign_attestation(attestation_data: AttestationData, attestation_duty: AttestationDuty) -> Attestation:
     """Returns a signed attestations that is constructed using the given attestation data & attestation duty.
@@ -96,13 +76,6 @@ def vc_sign_attestation(attestation_data: AttestationData, attestation_duty: Att
     pass
 
 
-def vc_is_slashable_block(block: BeaconBlock, validator_pubkey: BLSPubkey) -> bool:
-    """Checks whether the block is slashable according to the anti-slashing database.
-    This endpoint does not exist in beacon-APIs.
-    """
-    pass
-
-
 def vc_sign_block(block: BeaconBlock, proposer_duty: ProposerDuty) -> SignedBeaconBlock:
     """Returns a signed beacon block using the validator index given in the proposer duty.
     This endpoint does not exist in beacon-APIs.

glossary.md

@@ -1,23 +1,69 @@
-from dvspec.eth_node_interface import (
+from dataclasses import dataclass
+from typing import (
+    List,
+)
+
+from .eth_node_interface import (
     AttestationDuty,
     bn_submit_attestation,
     bn_submit_block,
     ProposerDuty,
     vc_sign_attestation,
     vc_sign_block,
 )
-from dvspec.consensus import (
+from .consensus import (
     consensus_on_attestation,
     consensus_on_block,
 )
-from dvspec.networking import (
+from .networking import (
     broadcast_threshold_signed_attestation,
     broadcast_threshold_signed_block,
     construct_signed_attestation,
     construct_signed_block,
     listen_for_threshold_signed_attestations,
     listen_for_threshold_signed_blocks
 )
+from .utils.types import (
+    BLSPubkey,
+    SlashingDB,
+    UInt64
+)
+
+
+@dataclass
+class ValidatorIdentity:
+    """Identity of the Ethereum validator.
+    """
+    # Ethereum public key
+    pubkey: BLSPubkey
+    # Index of Ethereum validator
+    index: UInt64
+
+
+@dataclass
+class CoValidator:
+    """Identity of distributed co-validator participating in the DV protocol.
+    """
+    # Identity of Ethereum validator that this co-validator performs duties for
+    validator_identity: ValidatorIdentity
+    # Secret-shared public key
+    pubkey: BLSPubkey
+    # Index of the co-validator in the distributed validator protocol
+    index: UInt64
+
+
+@dataclass
+class DistributedValidator:
+    """State object that tracks a single Ethereum validator being run using the distributed validator protocol.
+    """
+    validator_identity: ValidatorIdentity
+    co_validators: List[CoValidator]
+    slashing_db: SlashingDB
+
+
+@dataclass
+class State:
+    distributed_validators: List[DistributedValidator]
 
 
 def serve_attestation_duty(attestation_duty: AttestationDuty) -> None:
@@ -28,7 +74,6 @@ def serve_attestation_duty(attestation_duty: AttestationDuty) -> None:
     2. For each attestation_duty received in Step 1, schedule
         serve_attestation_duty(attestation_duty) at 1/3rd way through the slot
         attestation_duty.slot
-
     See notes here:
     https://github.com/ethereum/beacon-APIs/blob/05c1bc142e1a3fb2a63c79098743776241341d08/validator-flow.md#attestation
     """
@@ -50,7 +95,6 @@ def serve_proposer_duty(proposer_duty: ProposerDuty) -> None:
         bn_get_proposer_duties_for_epoch(epoch+1)
     2. For each proposer_duty received in Step 1 for our validators, schedule
         serve_proposer_duty(proposer_duty) at beginning of slot proposer_duty.slot
-
     See notes here:
     https://github.com/ethereum/beacon-APIs/blob/05c1bc142e1a3fb2a63c79098743776241341d08/validator-flow.md#block-proposing
     """

src/dvspec/consensus.py

@@ -0,0 +1,87 @@
+from dataclasses import dataclass
+from typing import (
+    List,
+)
+
+
+"""
+Basic Datatypes
+"""
+
+
+UInt64 = int
+Bytes32 = bytes
+Bytes48 = bytes
+Bytes96 = bytes
+
+
+"""
+Aliased Data Types
+"""
+
+Epoch = UInt64
+BLSPubkey = Bytes48
+BLSSignature = Bytes96
+CommitteeIndex = UInt64
+CommitteeLength = UInt64
+Root = Bytes32
+Slot = UInt64
+ValidatorIndex = UInt64
+Version = UInt64
+
+
+"""
+Types for EIP-3076 Slashing DB.
+See here for details:
+https://eips.ethereum.org/EIPS/eip-3076
+"""
+
+
+@dataclass
+class SlashingDBBlock:
+    slot: Slot
+    signing_root: Root
+
+
+@dataclass
+class SlashingDBAttestation:
+    source_epoch: Epoch
+    target_epoch: Epoch
+    signing_root: Root
+
+
+@dataclass
+class SlashingDBData:
+    pubkey: BLSPubkey
+    signed_blocks: List[SlashingDBBlock]
+    signed_attestations: List[SlashingDBAttestation]
+
+
+@dataclass
+class SlashingDB:
+    interchange_format_version: Version
+    genesis_validators_root: Root
+    data: List[SlashingDBData]
+
+
+"""
+Types for talking to VCs and BNs
+"""
+
+
+@dataclass
+class AttestationDuty:
+    pubkey: BLSPubkey
+    validator_index: ValidatorIndex
+    committee_index: CommitteeIndex
+    committee_length: UInt64
+    committees_at_slot: UInt64
+    validator_committee_index: ValidatorIndex  # TODO: Is this the correct datatype?
+    slot: Slot
+
+
+@dataclass
+class ProposerDuty:
+    pubkey: BLSPubkey
+    validator_index: ValidatorIndex
+    slot: Slot