Crate eth_bridge

Multi-network Ethereum Bridge pallet

Description

Provides functionality for cross-chain transfers of assets between Sora and Ethereum-based networks.

Overview

Bridge can be divided into 3 main parts:

1. Bridge pallet. A Substrate pallet (this one).
2. Middle-layer. A part of the bridge pallet, more precisely, off-chain workers.
3. Bridge contracts. A set of smart-contracts deployed on Ethereum-based networks.

Definitions

Thischain - working chain/network. Sidechain - external chain/network. Network - an ethereum-based network with a bridge contract.

Bridge pallet

Stores basic information about networks: peers’ accounts, requests and registered assets/tokens. Networks can be added and managed through requests. Requests can be incoming (came from sidechain) or outgoing (to sidechain). Each request has it’s own hash (differs from extrinsic hash), status (RequestStatus), some specific data and additional information. The requests life-cycle consists of 3 stages: validation, preparation and finalization. Requests are registered by accounts and finalized by bridge peers.

Middle-layer

Works through off-chain workers. Any substrate node can be a bridge peer with its own secret key (differs from validator’s key) and participate in bridge consensus (after election). The bridge peer set (Peers in storage) forms an n-of-m-multisignature account (BridgeAccount in storage), which is used to finalize all requests.

Bridge contract

Persists the same multi-sig account (+- 1 signatory) for validating all its incoming requests.

Re-exports

• pub use weights::WeightInfo;
• pub use pallet::*;

Modules

• migration
• offchain
• pallet
  The module that hosts all the FRAME types needed to add this pallet to a runtime.
• requests
• types
  Web3 Types
• weights
  Autogenerated weights for eth_bridge

Macros

• cancel

Structs

• BridgeAssetData
• NetworkConfig
  Network configuration.
• NetworkParams
  Network-specific parameters.
• NodeParams
  Ethereum node parameters (url, credentials).
• PeerConfig
  Local peer config. Contains a set of networks that the peer is responsible for.

Enums

• AssetConfig
  Bridge asset parameters.
• BridgeSignatureVersion
  Bridge function signature version
• BridgeStatus
  Bridge status.

Constants

• CONFIRMATION_INTERVAL
  A number of sidechain blocks needed to consider transaction as confirmed.
• DEPOSIT_TOPIC
  Contract’s Deposit(bytes32,uint256,address,bytes32) event topic.
• KEY_TYPE
• MAX_GET_LOGS_ITEMS
  Maximum number of Log items per eth_getLogs request.
• MINIMUM_PEERS_FOR_MIGRATION
  Minimum peers required to start bridge migration
• OFFCHAIN_TRANSACTION_WEIGHT_LIMIT
• STORAGE_ETH_NODE_PARAMS
• STORAGE_FAILED_PENDING_TRANSACTIONS_KEY
• STORAGE_NETWORK_IDS_KEY
• STORAGE_PEER_SECRET_KEY
• STORAGE_PENDING_TRANSACTIONS_KEY
• STORAGE_SUB_NODE_URL_KEY
• STORAGE_SUB_TO_HANDLE_FROM_HEIGHT_KEY
• TECH_ACCOUNT_AUTHORITY
• TECH_ACCOUNT_MAIN
• TECH_ACCOUNT_PREFIX