starknet

Disclaimer: Development in Progress

Please note that this project is actively under development. It is not ready for deployment on any mainnet environments. As we continue to experiment and test new ideas, expect significant changes to the interface. Please be prepared for ongoing modifications.

Hashed Timelock Contracts (HTLCs)

This part of the repository contains a cairo1.0 smart contract for implementing Hashed Timelock Contracts (HTLCs) on Starknet. This contract enables users to create, manage, and interact with HTLCs, facilitating secure and trustless transactions. The contract includes functions such as creating new HTLCs, redeeming funds locked in HTLCs with a secret hash, and refunding funds in case of expiration or non-redeem. Users can refer to the contract source code and documentation for detailed information on each function's usage and parameters.

Contract Overview

HashedTimelockERC20.cairo

Description: This contract allows users to create HTLCs for Starknet. It follows a protocol where a sender can create a new HTLC for a specific ERC20 token, a receiver can claim the ERC20 after revealing the secret, and the sender can refund the ERC20 if the time lock expires.

Functions

• commit: Allows a sender to create a new PreHTLC for EREC20 tokens by specifying the receiver, messenger, timelock, token contract, and amount.
• lock: Allows a sender to create a new HTLC for EREC20 tokens by specifying the receiver, hashlock, timelock, token contract, and amount.
• redeem: Allows the receiver to claim the EREC20 tokens locked in the HTLC by providing the secret hash.
• addLock: Allows the messenger to lock the commited funds by the given hashlock.
• unlock: Allows the sender to unlock the EREC20 tokens if the timelock expires and the receiver has not redeemed the funds.
• getDetails: Retrieves details of a specific HTLC/PreHTLC by its contract ID.

Deployment

Prerequisites

• starkli and scarb installed
• Starknet network connection (e.g., localhost, sepolia, etc.)
• Ether or test tokens for deployment gas fees

Steps

1. Clone this repository:

   git clone <repository_url>
   

2. Navigate to the project directory:

   cd <project_directory>
   

3. Create a signer:

   mkdir -p ~/.starkli-wallets/deployer
   

4. Set up your wallet:

   starkli signer keystore from-key ~/.starkli-wallets/deployer/my_keystore_1.json
   starkli account fetch <SMART_WALLET_ADDRESS> --output ~/.starkli-wallets/deployer/my_account_1.json --rpc <Alchemy_Startknet_URL>
   

5. Set Env Variables:

   export STARKNET_ACCOUNT=~/.starkli-wallets/deployer/my_account_1.json
   export STARKNET_KEYSTORE=~/.starkli-wallets/deployer/my_keystore_1.json
   export STARKNET_RPC=<Alchemy_Startknet_URL>
   

6. Build Contract:

   scarb build
   

7. Declarse class hash

   starkli declare ./target/dev/<YOUR_FILE_NAME>.contract_class.json
   

8. Deploy the contracts:

   starkli deploy <YOUR_CLASS_HASH>
   

Tests

There are 12 test types for the HTLC contract, written in the tests folder. The 12 test types are:

1. Non-existent HTLCs
   Can’t call any function if the HTLC ID doesn’t exist.

2. Redeeming HTLC
   Can redeem with a correct secret; fails with an incorrect secret.

3. Already Redeemed
   Can’t interact with an HTLC once it’s been redeemed.

4. Refunding
   Can refund after timelock expiry; fails before expiry.

5. Already Refunded
   No calls allowed once refunded.

6. Duplicate Creation
   Can’t create an HTLC with an ID that’s already used.

7. Non-positive Amount
   Amount must be > 0.

8. Insufficient Balance
   Sender needs enough tokens in their account.

9. Insufficient Allowance
   Contract needs allowance for the token amount.

10. Invalid Timelock
    Timelock must be set to a future timestamp.

11. addLock
    Only the messenger can set the hashlock; must be new and within time.

12. addLock with Signature
    Validates off-chain signature; rejects bad data or wrong signer.

Usage Once deployed, users can interact with the contracts using Starknet wallets or through contract function calls programmatically.

For HashedTimelockERC20.cairo: Users can create HTLCs for ERC20 tokens, redeem tokens, and request refunds. Refer to the contract source code for function details and usage instructions.

License This project is licensed under the MIT License. See the LICENSE file for details.