Metamask: Integrating KMS with ethers _signTypedData (EIP712)

Here is an article on Metamk Integration with Ester Signed Data:

KMS Integration with Esters: Step by Step Signed Data Data

The use of the main governance systems (KMS) in recent years has become increasingly popular in the development of blockchain. One such system is Amazon KMS (Amazon Web Services Key Management Service), which provides secure key management and encryption services for various applications.

One of the widespread requirements in developing smart contracts for Ethereum is the ability to sign printed data using a private key stored in the environmental changing. In this article, we will look at how to integrate KM with ethers for signing a printed data check.

Why sign printed data?

Before diving into the integration process, let’s briefly discuss why printed data (EIP712) is essential:

* Tamer-Deendent : The signature provides evidence that the data has been created and signed by the holder.

* Insufficient : This ensures that the sender cannot deny that he has created data.

Private key environment variables

You need to use environmental variables to safely store private keys. This approach allows users to manage their keys without subjecting them to the code.

`JavaScript

// Environmental Changing Setup

Const Privatekey = Process.env.Key_private;

`

KMS Setting with Esters

To integrate metamas with ethers, we will use Ethers' and 'ethers.js' packages. Install the required packages first:

bash

NPM Install Ethers @Types/Esters

`

Set your Ethereum purse and account below. In this example, let’s say you have a Metamk safe.

Generation of printed printed data

We will use the Ethers/Web3 package to generate the signed printed data using KMS. First, set up a contract with the feature generating the signed data:

`JavaScript

// EIP-712 Example Definition of Print Data Structure

CONST STRUCT = {

Fields: [

{Name: ‘Name’, type: ‘string’},

{Word: ‘version’, type: ‘number’}

]

};

Export Const Typeddastrict = Struct;

Export Function Generedydypeddata (Data) {

// generate a random signature

Const Sig = Crypto.Createsign (‘Sha256’);

Sig.update (Buffer.from (typeddatatastruct, ‘UTF8’));

// Sign data using private key (environmental variable)

Const Signature = Sig.sign (Privatekey);

return {signature};

}

`

Signing the signed data with Metamass

Now that we have a «Generesigntypeddata» function, let’s integrate it with your contract. First, create an interface for signed printed data:

`JavaScript

// Definition of EIP-721 Structure for the Definition of Agreement

CONST STRUCT = {

Fields: [

{Name: ‘Name’, type: ‘string’},

{Word: ‘version’, type: ‘number’}

]

};

Export Const EIP721 = Structs;

Export Function Generedydypeddata (Data) {

Return Generative Typeddata ({Name: Data.name, version: Data.Version});

}

`

Finally, we can use the «EIP721» interface to sign recorded data in our contract:

`JavaScript

// Example of a contract code passage (NODE.JS)

Import {EIP721} from ‘./Interface’;

Const Agreement = New Ethers.Contract (‘0x … Agreement Address …’, EIP721);

ASYNC Function1 () {

Const Data = {Name: ‘Agreement Example’, version: 1};

Try {

Const Signature = Expect Agreement.GeneresSignTypeddata (Data);

Console.log (Signature: $ {Signature});

} Catch (error) {

Console.Error (error);

}

}

`

Code launch

To run this code, you will need to set the local Ethereum blockchain using Metamk or other compatible purse. When you have a valid account and a private key setting, you can collect your EIP-721 contract and use it with Metamk.

`bash

Development of NPX Hardhat.

solana token account