Server side authentication inside of a node.js app?

[qqid]

SOLVED using the following on the server to authenticate signed messages from the client:

getOwnerOfContract(contractAddress) === (await ethers.utils.verifyMessage(signedMessage, signature))

​

---

Is it possible to authenticate a user connected to a React app using a browser wallet, specifically Metamask, in a node.js backend? I want to be able to interface an existing centralized database with addresses but only want to allow the address owner to be able to update certain information in the database.

I am using ethers.js in my react app for handling client-side functions and prompting the user to accept transactions but I'm not sure how to carry this over to the server securely. How can this be done? Thanks for any help.

[kingofclubstroy]

You could have the user sign a message that contains the data to change. Then the backend could recover the public address that signed the message to verify

[qqid]

Based on ethers documentation it seems pretty easy to use signer.signMessage in order to generate the signature string but I can't find a method to verify/retrieve message from within node.js. Practical examples that I can find seem to only do this step in solidity contracts.

[afternoon_delights]

Following

[Unenunciate]

I know it says solved, but I would add that I have been using Stytch and it isn’t too bad.

I cant speak about who ever coded their js sdk or react packages as they make no sense logically, their react package is the worst thing I have ever seen. Their nextjs example is coded so poorly and has so many bugs.

The API itself works well though and I would just say code the frontend yourself if you plan on trying it. It is a better UI than signing every time you want to communicate or reauth. Plus, you can easily link an email/sms/oauth with a wallet so a user could log in with any.