Escrow Funds from Provider to Sender on Gateway Contract

[OnahProsperity]

Objective:
Create a function that escrows assets from the provider to the sender in the Gateway contract as part of the on-ramping process.

Function Parameters:

/** 
 * @notice Escrowed assets from provider to the sender.
 * @param _orderId The ID of the transaction.
 * @param _signature The signature of the provider.
 * @param _provider The address of the provider.
 * @param _senderAddress The address of the sender.
 * @param _asset The address of the asset.
 * @param _amount The amount to be transferred.
 * @return bool the withdrawal is successful.
 */

Requirements:

1. Functionality:

• Implement a function that escrows assets from a provider to a sender’s address.
• The function should verify that the provider has staked sufficient assets in the Gateway contract for the escrow.
• The assets will be transferred from the provider’s locked balance (staked balance) to the sender as part of the onramping process.

2. Checks:

• Ensure the _signature provided is valid and signed by the provider.
• Use ecrecover to validate the signature against the provider’s address.
• Sufficient Balance Check:
• Ensure the provider has enough staked assets to cover the amount being escrowed.
• Use required statements to prevent escrowing more assets than the provider has locked.

3. Order Validation:

• Ensure the _orderId is unique and hasn’t been processed before, preventing double-spending of assets.

4. Storage:

• Keep a record of all processed orders to prevent re-processing.
  mapping(bytes32 => bool) public processedOrders;
• Update the provider’s staked balance after a successful escrow.
• Add a nonce to the signature to avoid a replay attack
• Optionally, track escrowed balances in another mapping if needed.
• Transfer the assets from the provider’s staked balance to the sender’s address.

5. Event Emission:

• Emit an Escrow event upon successful escrow completion.
  event Escrow(address indexed provider, address indexed sender, uint256 amount, bytes32 orderId);

6. Return Value:

• Return true if the escrow was successful and assets were transferred.

This task ensures the secure transfer of assets from a provider’s staked funds to a sender while checking for sufficient balance, signature validity, and preventing order replay.