Bridge Contract

Overview

The Bridge contract facilitates ERC20 cross-chain transfers by handling deposits and withdrawals between supported chains. It ensures secure and validated token transfers using Merkle proofs and cryptographic signatures.

Functions

deposit

Purpose: Allows users to deposit ERC20 tokens to the target chain.

Parameters:

• ChainId target: The target chain ID where the tokens will be transferred.
• Token token: The token to be deposited.
• uint256 amount: The amount of tokens to be deposited.

Details:

• Creates a bridge message containing transaction details.
• Transfers the specified tokens from the sender to the contract.
• Emits a Deposit event with the encoded bridge message.

withdraw

Purpose: Allows users to withdraw ERC20 tokens from the source chain.

Parameters:

• BridgeMessage calldata bridgeMsg: The bridge message containing the details of the transaction.
• bytes32[] calldata proof: The Merkle proof validating the transaction.

Details:

• Validates the bridge message and Merkle proof.
• Determines the output token (wrapped or original).
• Transfers the specified tokens from the contract to the recipient.
• Emits a Withdraw event with the transaction details.

update

Purpose: Updates the Merkle root of the source chain.

Parameters:

• UpdateHashMessage calldata updateMsg: The update message containing the new Merkle roots and block numbers.
• bytes[] calldata signatures: The cryptographic signatures validating the update.

Details:

• Validates the update message and signatures.
• Sets the new Merkle root for each specified block number.
• Emits an Update event with the update details.

updateQuorum

Purpose: Updates the quorum of the target chain.

Parameters:

• UpdateQuorumMessage calldata updateMsg: The update message containing the new signers.
• bytes[] calldata signatures: The cryptographic signatures validating the update.

Details:

• Validates the update message and signatures.
• Sets the new quorum of signers.
• Emits an UpdateQuorum event with the update details.

setMinimumConfirmation

Purpose: Sets the minimum confirmation for a specific chain.

Parameters:

• SetChainConfigMessage calldata setMsg: The chain config message containing the new minimum confirmation.
• bytes[] calldata signatures: The cryptographic signatures validating the update.

Details:

• Validates the set message and signatures.
• Sets the new minimum confirmation for the specified chain.
• Emits a SetChainConfig event with the update details.

Installation:

1. Clone

$ git clone https://github.com/havi-kim/simple_bridge
$ cd simple_bridge

2. Install foundry

$ curl -L https://foundry.paradigm.xyz | bash
$ foundryup

3. Compile

$ forge build

4. Test

$ forge test

5. Run script

$ PK=0x... forge script scripts/....sol --rpc-url http://... --broadcast