Best way to managed who can sign in ? (with prisma)

[laurent512]

Hello,

First of all thank you for the great library, I am grateful for the amazing job you are doing.

In my project, I enabled github providers with prisma adapter for authentication.
Issue is that I would love to be able to filter who can sign In based on their email address.

I saw the callback method proposal and wondering what is the best (safe & easy) way to filter who can sign in.

async signIn({ user, account, profile, email, credentials }) {
      const isAllowedToSignIn = true;
      if (isAllowedToSignIn) {
        return true;
      } else {
        // Return false to display a default error message
        return false;
        // Or you can return a URL to redirect to:
        // return '/unauthorized'
      }
    },

For example, is it a working solution that in my User table of prisma, I add by myself record containing only the email of people allowed and verify in the signin callback if the email is present in that database ?
Would that be a safe solution ?

model User {
  id              String    @id @default(cuid())
  name            String?
  email           String?   @unique
  emailVerified   DateTime?
  image           String?
  accounts        Account[]
  sessions        Session[]
}

Thank you in advance !

[laurent512]

Any idea ? I would also appreciate any redirection ^^

[ThangHuuVu]

signIn is the intended place to achieve your goal. You could use the userId included in user or account to query the DB and check. Something like:

async signIn({ user, account, profile, email, credentials }) {
      const user = prisma.user.findUnique({
        where: {
          id: user.id
        }
      })
      if (user.email) {
        return true;
      } else {
        // Return false to display a default error message
        return false;
        // Or you can return a URL to redirect to:
        // return '/unauthorized'
      }
    },