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Add Custom Metadata Signature Structure

Centralized Verification

NameService signatures are verified by Core.sol using validateAndConsumeNonce(). Uses NameServiceHashUtils.hashDataForAddCustomMetadata() for hash generation.

To authorize the addCustomMetadata operation within the Name Service, the user who currently owns the username must generate a cryptographic signature compliant with the EIP-191 standard using the Ethereum Signed Message format.

Signature Format​

{evvmId},{senderExecutor},{hashPayload},{originExecutor},{nonce},{isAsyncExec}

Hash Payload Generation​

import {NameServiceHashUtils} from "@evvm/testnet-contracts/library/signature/NameServiceHashUtils.sol";

bytes32 hashPayload = NameServiceHashUtils.hashDataForAddCustomMetadata(
    identity,  // Username
    value      // Metadata value
);
// Internal: keccak256(abi.encode("addCustomMetadata", identity, value))

Example​

Scenario: Owner wants to add custom metadata to their identity "alice"

string memory identity = "alice";
string memory value = "https://alice.example.com/profile";

bytes32 hashPayload = NameServiceHashUtils.hashDataForAddCustomMetadata(identity, value);

Message: 1,0x0000000000000000000000000000000000000000,0x[hashPayload],0x0000000000000000000000000000000000000000,12,true

Technical Details
  • Custom Fields: Allows arbitrary data storage linked to username
  • Owner-Only: Only current username owner can add metadata
  • Hash Independence: Hash payload does NOT include executors
  • EIP-191 Compliance: Uses "\x19Ethereum Signed Message:\n" prefix with message length
  • Authorization: Only the current owner of the identity can add custom metadata
  • Flexible Data: _value can contain any string data (URLs, descriptions, custom information)
  • Metadata Management: Allows users to associate additional information with their identities
  • Replay Protection: _nameServiceNonce prevents replay attacks
  • EVVM ID: Identifies the specific EVVM instance for signature verification

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