Add defensive validation to ensure the Ethereum sovereign account has sufficient balance before unlocking tokens. This addresses an audit finding where the lack of explicit balance checking created an unreliable security control that depended on implicit runtime behavior. Changes: - Add InsufficientSovereignBalance error variant for clear error messaging - Add explicit balance check in unlock_tokens before transfer - Update tests across all runtimes (testnet, stagenet, mainnet) to validate the specific error is returned when sovereign account has insufficient funds The explicit check provides better error messages that can propagate through the Ethereum bridge and makes debugging sovereign account balance issues easier. |
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| Cargo.toml | ||
| README.md | ||
DataHaven Native Transfer Pallet
A Substrate pallet that enables cross-chain transfers of DataHaven native tokens to and from Ethereum using the Snowbridge infrastructure.
Overview
This pallet facilitates the transfer of DataHaven (DH) native tokens to Ethereum, where they are represented as wrapped ERC20 tokens. It implements a lock-and-mint mechanism: tokens are locked on DataHaven when transferred to Ethereum, and unlocked when transferred back.
Features
- Cross-chain Transfers: Transfer DH tokens to Ethereum addresses
- Token Locking: Secure token locking in a sovereign account during transfers
- Fee Management: Mandatory fee collection for bridge relayers
- Pause Mechanism: Emergency pause functionality for security
Fee Structure
Fees are mandatory for all transfers and serve to:
- Compensate relayers for Ethereum gas costs
- Provide incentive for timely message delivery
- Prevent spam transactions
The fee is:
- Collected in DataHaven native tokens
- Transferred to a designated fee recipient account
- Separate from the transfer amount
Fee Calculation Guidelines
When calculating fees, consider:
- Ethereum Gas Costs: Estimate gas required for the Ethereum transaction
- Gas Price: Current Ethereum gas prices (use oracles or fixed estimates)
- Exchange Rate: DH to ETH conversion rate
- Relayer Margin: Additional incentive
Example calculation:
Ethereum gas required: 100,000 gas
Gas price: 30 gwei
ETH cost: 0.003 ETH
DH/ETH rate: 1000 DH per ETH
Base fee: 3 DH
With 20% margin: 3.6 DH
Extrinsics
transfer_to_ethereum
Transfer DataHaven native tokens to an Ethereum address.
Parameters:
origin: The account initiating the transferrecipient: The Ethereum address (H160) to receive the tokensamount: The amount of tokens to transferfee: The fee to cover Ethereum gas costs and incentivize relayers (must be non-zero)
pause
Pause all transfers. Only callable by PauseOrigin (typically governance).
unpause
Resume transfers after pause. Only callable by PauseOrigin.
Public Functions
total_locked_balance
Get the total balance of tokens locked in the Ethereum sovereign account.
ethereum_sovereign_account
Get the account ID of the Ethereum sovereign account for monitoring purposes.
Events
TokensLocked: Emitted when tokens are locked for transferTokensUnlocked: Emitted when tokens are unlocked from EthereumTokensTransferredToEthereum: Emitted on successful transfer to EthereumPaused: Emitted when the pallet is pausedUnpaused: Emitted when the pallet is unpaused
Errors
InsufficientBalance: Account has insufficient balance for transferOverflow: Arithmetic overflow in calculationsSendMessageFailed: Failed to send message through SnowbridgeInvalidEthereumAddress: Provided Ethereum address is zeroInvalidAmount: Transfer amount is zeroTransfersDisabled: Transfers are pausedZeroFee: Fee cannot be zero
Security Considerations
- Pause Mechanism: The pallet can be paused by governance in case of emergencies
- Fee Validation: All transfers require non-zero fees to prevent spam
- Balance Preservation: The pallet uses
Preservation::Preserveto maintain existential deposits - Address Validation: Zero Ethereum addresses are rejected