How to verify the tKey private key in the Backend?

[polartar]

I am using self-hosting and just logged in and got the tKey private key

   const webStorageModule = tKey.modules['webStorage'] as WebStorageModule;
   await webStorageModule.inputShareFromWebStorage();
   const indexes = tKey.getCurrentShareIndexes();
   const reconstructedKey = await tKey.reconstructKey();

After this,
- I just want to verify the reconstructedKey or reconstructedKey.privKey on the backend.
- I want to get the email from this private key
- I want to logout

Can anyone help me?

[yashovardhan]

Hey @talentdev2020

Thanks for trying out Web3Auth Self Host. Coming to your questions:

I just want to verify the reconstructedKey or reconstructedKey.privKey on the backend.

How do you want to verify the key, I'm not sure about the question. This is because the key is reconstructed on the frontend, and to be non custodial we do not have any direct way for you to verify key on the backend - it might mean storing it somewhere and then checking it. I might suggest checking the user's information from the service provider rather to verify them.

I want to get the email from this private key

You cannot get an email from the private key, but rather on login, you can check with the service provider about the user information. Our Custom Auth SDK is the base for Torus Service Provider, you can see that documentation to execute the user information function: https://github.com/torusresearch/customauth
Additionally, if you're using your own custom authentication, you can directly get the user details from the JWT id_token issued by the login provider.

I want to logout

You can directly trigger the logout function of your login provider from which you're using the custom authentication. I don't think you need a logout function from the Tkey SDK for this. The role of the tkey sdk is to generate/ reconstruct the key. All the login flows are directly handled by you with your login provider.

[polartar]

thanks @yashovardhan.

I got the private key, public keys (x, y), and god idToken. I want to verify these public keys and idToken on the backend.
When web3auth/web3auth, I verified them by using https://web3auth.io/docs/server-side-verification/external-wallets#verifying-idtoken-in-backend

But when using tKey, it said error

[yashovardhan]

Thanks for explaining the issue. This particular feature about server side authentication is not currently available in self host. We'll update your once it is available. You might like to manually do it within your server currently.