preRegistrationUsername

Function Type: public
Function Signature: preRegistrationUsername(address,bytes32,uint256,bytes,uint256,uint256,bool,bytes)
Function Selector: 0x393b9c6f

Pre-registers a username hash to prevent front-running attacks during the registration process. This function creates a temporary reservation that can be registered after a 30-minute waiting period. The function uses a commitment-reveal scheme where users first commit to a hash of their desired username plus a secret number.

Parameters

Parameter	Type	Description
user	address	The address of the end-user initiating the pre-registration.
hashPreRegisteredUsername	bytes32	The pre-commitment hash calculated as keccak256(abi.encodePacked(username, clowNumber)).
nonce	uint256	The user's nonce specific to this NameService contract for replay protection of this pre-registration action.
signature	bytes	The EIP-191 signature from user authorizing this pre-registration action.
priorityFee_EVVM	uint256	Optional fee (in principal tokens) paid by user to the msg.sender (staker executing the transaction) via the EVVM contract.
nonce_EVVM	uint256	Required if priorityFee_EVVM > 0. user's nonce for the EVVM payment function call used only to pay the priority fee.
priorityFlag_EVVM	bool	Required if priorityFee_EVVM > 0. Priority flag (sync/async) for the EVVM payment call paying the priority fee.
signature_EVVM	bytes	Required if priorityFee_EVVM > 0. user's signature authorizing the EVVM payment call paying the priority fee.

note

• The EVVM payment signature (signature_EVVM) is only needed if paying a priority fee and follows the Single Payment Signature Structure.
• The NameService pre-registration signature (signature) follows the Pre-Registration Signature Structure.
• The EVVM parameters (nonce_EVVM, priorityFlag_EVVM, signature_EVVM) are only required and processed if priorityFee_EVVM is greater than zero.

Hash Username Structure

The hashPreRegisteredUsername is calculated off-chain by the user using SHA3-256 (keccak256):

keccak256(abi.encodePacked(username, clowNumber));

Where:

• username (string): The desired username.
• clowNumber (uint256): A secret number chosen by the user, required later during the registrationUsername step to validate the commitment.

Execution Methods

This function can be executed by any address, with staker rewards only distributed to stakers.

Fisher Execution

When the executor is the fisher:

1. The user sends the payment request to the fishing spot
2. The fisher captures the transaction and validates all parameters
3. The fisher submits the transaction to the contract for processing

Direct Execution

When the executor is the user or a service:

1. The user/service submits their transaction directly to the contract

Workflow

1. NameService Nonce Verification: Checks if the provided nonce is unused for the user using the verifyIfNonceIsAvailable modifier. Reverts if used.

2. Pre-registration Signature Verification: Verifies the signature provided by user using verifyMessageSignedForPreRegistrationUsername. Reverts with InvalidSignatureOnNameService if invalid.

3. Priority Fee Processing: If priorityFee_EVVM > 0, calls the makePay function to process the priority fee payment through EVVM using the provided EVVM parameters.

4. Hash Storage: Records the pre-registration by storing the hashPreRegisteredUsername with:

   • Key: "@" + hashPreRegisteredUsername (converted to string)
   • Owner: user
   • Expiration: block.timestamp + 30 minutes
   • Flags: Marked as not a username (flagNotAUsername = 0x01)

5. Nonce Management: Marks the NameService nonce as used for the user in the nameServiceNonce mapping.

6. Staker Rewards: If the executor (msg.sender) is a staker (isAddressStaker(msg.sender)), distributes rewards via makeCaPay:

   • Base MATE reward (getRewardAmount())
   • Plus the priorityFee_EVVM amount