az0mb13 / bridge-contracts

bridge-contracts

EVM & Archethic smart contract for Archethic's Bridge

Development

In order to develop and test the contracts, you need to have some prerequisites:

• Node.js

• EVM:

  • Ganache (Simulation of the Ethereum's node)
  • Truffle

• Archethic:

  • Archethic node (running in devnet mode)

EVM contracts

There are different kind of EVM smart contracts:

• HTLC
• Liquidity pools

All the contract have their own type depending on the token used: native or ERC, because transfers/balance verification acts differently.

HTLC

Those contract provide the atomic swap logic.

There are few types

• Signed: contract where a signature from the Archethic's pool is required to provision the contract or to withdraw funds
• Chargeable: contract where a fee is defined and in which the pool is assigning the recipient

classDiagram
    HTLC <|-- HTLC_ERC
    HTLC <|-- HTLC_ETH
    HTLC_ERC <|-- SignedHTLC_ERC
    HTLC_ERC <|-- ChargeableHTLC_ERC
    HTLC_ETH <|-- SignedHTLC_ETH
    HTLC_ETH <|-- ChargeableHTLC_ETH

Liquidity pools contracts

classDiagram
    Pool <|-- LP_ERC
    Pool <|-- LP_ETH

Test SC

cd evm

For tests you can use unit tests:

truffle test

To use the pool in a local environment you can use migrations with:

truffle deploy

This will create two pools for ETH and ERC. It will also create a dummy token, accessible via LP_ERC.token()

In order to test the signature from the LP Archethic pool you can use this tool to generate the signature:

node signing_tool.js 0x[DIGEST] 0x00d171013047636e2af5c7645377ed3e82f07d8ffe95a2aa65520306046be93f

The last parameter being the private key of the accounts[6] configured as the signer key in the migrations for the development network on Ganache

Archethic Smart Contracts

There is three kind of SC:

• Factory contract
• HTLC
• Pool contracts

Factory contract

This contract is a helper for DApps UI and for Pool contracts to build and verify HTLC. It also helps Pool contracts for minting new tokens.

Here is the public functions:

• get_chargeable_htlc(end_time, user_address, pool_address, secret_hash, token, amount)
  It returns the code of a HTLC for fund going from EVM chain => Archethic

  • end_time: the limit timestamp for the swap
  • user_address: the destination address on Archethic
  • pool_address: the address of the Archethic pool to request funds
  • secret_hash: the hash of the secret generated by user
  • token: the token address to swap or "UCO"
  • amount: the amount of token the user wants to receive on Archethic

• get_signed_htlc(end_time, user_address, pool_address, token, amount)
  It returns the code of a HTLC for fund going from Archehtic => EVM chain

  • end_time: the limit timestamp for the swap
  • user_address: the user address on Archethic
  • pool_address: the address of the Archethic pool to request secret
  • token: the token address to swap or "UCO"
  • amount: the amount of token the user wants to receive on EVM chain

• get_protocol_fee
  It returns the protocol fees in percentage (0.3 => 0.3% = 0.003)

• get_protocol_fee_address
  It returns the address where the protocol fees are sent

HTLC

Those contracts implement the logic of atomic swap. There is two types of contracts:

• Chargeable HTLC: used when swapping from EVM chain to Archethic.
  On creation, this contract needs to request funds to a pool. To do it the transaction that contains the code should also add the pool in the recipient with the parameters end_time, user_address, secret_hash, amount
• Signed HTLC: use when swapping from Archethic to EVM chain.
  On creation, this contrat needs to request a secret hash from a pool. To do it the transaction that contains the code should also add the pool in recipient with the parameters end_time, user_address, amount

Pool Contracts

Those contract are responsible for creating new tokens and signing action to make a proof for EVM chain that actions has been done on Archethic.
There is one contract version for token and one for UCO

Script example

To help interaction with smart contracts, some helper scripts are available in js.
A config.js file is provided to configure poolSeed, userSeed, factorySeed and endpoint.

deploy_pool.js

Used to deploy a pool.

node deploy_pool.js

deploy_chargeable_hltc.js

Used to deploy a chargeable HTLC for EVM chain => Archethic.
Parameters:

• htlc_seed: the seed to use for deploying the htlc
• end_time: the limit time for the swap
• amount: the amount to receive from the pool
• secret_hash: the hash of the secret generated by user

node deploy_chargeable_hltc.js htlc1 1692394020 4 2cf24dba5fb0a30e26e83b2ac5b9e29e1b161e5c1fa7425e73043362938b9824

reveal_secret.js

Used to reveal the secret to a chargeable htlc. Parameters:

• htlc_address: one address of the htlc chain (could be the genesis address)
• secret: the secret that has been used to create the contract

node reveal_secret.js 0000ec9c3a34e791bda21bbcb69ea0eb875857497e0d48c75771b3d1adb5073ce791 hello

deploy_signed_hltc.js

Used to deploy a signed HTLC for Archethic => EVM chain.
Parameters:

• htlc_seed: the seed to use for deploying the htlc
• end_time: the limit time for the swap
• amount: the amount to receive from the pool

node deploy_signed_hltc.js htlc1 1692394020 4

request_secret.js

Used to request the secret to a pool for a signed htlc. Parameters:

• htlc_genesis_address: the genesis_address of the htlc

node request_secret.js 0000ec9c3a34e791bda21bbcb69ea0eb875857497e0d48c75771b3d1adb5073ce791

use the mnemonic test