Re-authenticating User Credentials Swift

Question

I wish to re-authenticate a user prior to allowing them to change their login information. However, due to the recent Firebase update, I found the documentation rather unhelpful. Using this link I produced the following authenticateUser() function.

func authenticateUser()
{
    let user = FIRAuth.auth()?.currentUser
    var credential: FIRAuthCredential

    //prompt user to re-enter info

    user?.reauthenticateWithCredential(credential, completion: { (error) in
        if error != nil
        {
            self.displayAlertMessage("Error reauthenticating user")
        }
        else
        {
            //user reauthenticated successfully
        }
    })
}

However, I am unsure what to do with the credential variable of type FIRAuthCredential, in order to re-authenticate the user. The documentation for this class can be found here.

Solution 1

Getting the FIRAuthCredential object depends on what provider you want to use to reauthenticate.

Email:

let credential = EmailAuthProvider.credential(withEmail: email, password: password)

Facebook:

let credential = FacebookAuthProvider.credential(withAccessToken: FBSDKAccessToken.currentAccessToken().tokenString)

Twitter:

let credential = TwitterAuthProvider.credential(withToken: session.authToken, secret: session.authTokenSecret)

Google:

let authentication = user.authentication
let credential = GoogleAuthProvider.credential(withIDToken: authentication.idToken, accessToken: authentication.accessToken)

Solution 2

In Swift 4 and latest firebase 4 the names have changed a bit, but the principle still remains. For your convenience:

    let eMail = EmailAuthProvider.credential(withEmail: "[email protected]", password: "somepassword")
    let fb = FacebookAuthProvider.credential(withAccessToken: "xxx")
    let g = GoogleAuthProvider.credential(withIDToken: "xxx", accessToken: "xxx")
    ...

    Auth.auth().currentUser?.reauthenticate(with: eMail, completion: {
        [weak self]
        (error) in
        ...
    })

Solution 3

Firebase's documentation is currently outdated. Here is the correct way to handle reauthenticate.

let user = Auth.auth().currentUser

user?.reauthenticate(with: credential, completion: { (result, error) in
   if let err = error {
      //..read error message             
   } else {
      //.. go on              
   }
})

Comments

[ayalcin]

let authentication = user.authentication is missing, how can we get that HixField ?

[HixField]

Sorry, don't understand your question. Can you be more specific?

[ayalcin]

I need to change email address for google accounts. I am using currentUser.updateEmail() function which requires currentUser.reauthenticate() However I can not get GIDSignIn.sharedInstance().currentUser.authentication to get IdToken and AccessToken. GIDSignIn.sharedInstance().currentUser returns nil. I am using FirebaseAuthUI for login & register. And my current user = Auth.auth().currentUser does not have authentication property

[HixField]

I am not using the firebaseui, sorry

[Visal Sambo]

what about phone number reauthentication?

[Clint]

How can I get the email and password for the cred?

[Clint]

What do I put into the email and password fields?

[temp_]

@Clint I think you are asking about EmailAuthProvider which you can use let credential = EmailAuthProvider.credential(withEmail: "[email protected]", password: "myPassword").

[Clint]

yes I apologize that is correct. Am I suppose to actually enter something in the Email: “email” and password: “ password”?

[temp_]

@Clint If your app requires a login, this would be the user's email and password. How you save/get the user's info is up to you. Using reauthenticate assumes you already have authenticated the user in the past. So you should already have the email and password, otherwise you need to look into how to authenticate not reauthenticate .

[Clint]

Oh I see, So I already saved the users email to the database however I never save passwords.. So thats a problem. The only way for me to get the users current password for reauthentication is to save the users current password? ( I want to avoid having them enter their old password)

[temp_]

@Clint you may need ask the user for them again or start using NSUserDefaults to save user passwords locally.

[Clint]

Do you mind helping me with my question, you definitely know how re authentication works. I can’t link it since I’m on my phone. But if you visit my profile it’s my most recent question..

[Shredder2794]

Note that as of 2020 it's slightly updated to: var credential = EmailAuthProvider.credential(withEmail: email, password: password)

[Pablo Sanchez Gomez]

@Shredder2794 OMG Thanks so much!!! I have been looking for this for a long time! :)