evmSignTypedData

Ethereum: sign typed data

Asks the device to sign an EIP-712 typed data message using the private key derived from the given BIP32 path.

User is asked to confirm all signing details on Ukey Wallet device.

• Supports EIP-712 (v3 and v4)
• Use evmSignTypedData for signing typed structured data
• Not for EIP-191 typed data signing
• For EIP-191 personal_sign, use evmSignMessage

const result = await HardwareSDK.evmSignTypedData(connectId, deviceId, params);

Params

Optional common params

• path - required string | Array<number> minimum length is 3. read more
• data - required Object type of EthereumSignTypedDataMessage. A JSON Schema definition can be found in the EIP-712 spec.
• metamaskV4Compat - required boolean set to true for compatibility with MetaMask's signTypedData_v4.
• chainId - optional number identifies the target Ethereum network and helps distinguish different chain configurations. Reference.

Blind signing

You may also wish to construct your own hashes using a different library.

• domainHash - required string hex-encoded 32-byte hash of the EIP-712 domain.
• messageHash - optional string hex-encoded 32-byte hash of the EIP-712 message. This is optional for the domain-only hashes where primaryType is EIP712Domain.

When blind signing is used

• Use UKey Lite 24, UKey Lite 25, or UKey Core 26.
• There are arrays nested in data.
• Firmware version is less than 4.4.0, and the data size is greater than 1KB.
• Firmware version is greater than or equal to 4.4.0 and the data size is greater than 1.5KB.

Example

const eip712Data = {
  types: {
    EIP712Domain: [
      {
        name: "name",
        type: "string",
      },
    ],
    Message: [
      {
        name: "Wallet Name",
        type: "string",
      },
      {
        name: "Amount",
        type: "uint64",
      },
    ],
  },
  primaryType: "Message",
  domain: {
    name: "example.ukey.io",
  },
  message: {
    "Wallet Name": "UKey Wallet",
    // be careful with JavaScript numbers: MAX_SAFE_INTEGER is quite low
    Amount: `${2n ** 54n}`,
  },
};

const { domainHash, messageHash } = transformTypedDataPlugin(eip712Data, true);

HardwareSDK.evmSignTypedData(connectId, deviceId, {
  path: "m/44'/60'/0'/0/0",
  data: eip712Data,
  metamaskV4Compat: true,
  domainHash,
  messageHash,
  chainId: 1,
});

Result

{
    success: true,
    payload: {
        address: string,
        signature: string, // hexadecimal string with "0x" prefix
    }
}

Error

{
    success: false,
    payload: {
        error: string, // error message
        code: number // error code
    }
}