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Renew Username Signature Structure

To authorize the renewUsername operation within the Name Service, the user (the current username owner) must generate a cryptographic signature compliant with the EIP-191 standard using the Ethereum Signed Message format.

The signature verification process uses the SignatureRecover library. This signature proves the owner's intent and authorization to extend the validity period of their username registration.

Signed Message Format​

The signature verification uses the SignatureRecover.signatureVerification function with the following structure:

SignatureRecover.signatureVerification(
    Strings.toString(evvmID),                           // EVVM ID as string
    "renewUsername",                                    // Action type
    string.concat(                                      // Concatenated parameters
        _username,
        ",",
        Strings.toString(_nameServiceNonce)
    ),
    signature,
    signer
);

Internal Message Construction​

This results in a message format:

"{evvmID},renewUsername,{username},{nameServiceNonce}"

Message Components​

1. EVVM ID (String):

  • The result of Strings.toString(evvmID)
  • Purpose: Identifies the specific EVVM instance

2. Action Type (String):

  • Fixed value: "renewUsername"
  • Purpose: Identifies this as a username renewal operation

3. Concatenated Parameters (String):

3.1. Target Username (String):

  • The _username string itself
  • Purpose: Specifies the username whose registration is being renewed

3.2. Name Service Nonce (String):

  • The result of Strings.toString(_nameServiceNonce)
  • Purpose: Provides replay protection for renewal actions

Example​

Scenario: Current owner wants to renew their username "alice"

Parameters:

  • evvmID: 1
  • _username: "alice"
  • _nameServiceNonce: 8

Signature verification call:

SignatureRecover.signatureVerification(
    "1",
    "renewUsername",
    "alice,8",
    signature,
    signer
);

Final message to be signed:

1,renewUsername,alice,8

EIP-191 formatted message hash:

keccak256(abi.encodePacked(
    "\x19Ethereum Signed Message:\n22",
    "1,renewUsername,alice,8"
))
Technical Details
  • Message Format: "{evvmID},{functionName},{parameters}"
  • EIP-191 Compliance: Uses "\x19Ethereum Signed Message:\n" prefix with message length
  • Authorization: Only the current owner of the username can renew their own username
  • Renewal Logic: Extends the username's expiration period and may involve a renewal fee
  • Replay Protection: _nameServiceNonce prevents replay attacks
  • EVVM ID: Identifies the specific EVVM instance for signature verification