Import external user to firebase


I want to import users from an external database to firebase.

The password were hashed with a sha256 function with the password prepended by a salt (which is a UUID).

For example:

password = "123qwerty!"
salt = "cb60eb29-95a2-418e-be2a-c1c107fb1add"
hash = sha256(salt+password)
# 54ccb21d42c6961aa1b666b7cb0485f85aab2f2323399fb2959ea5e4e9f6f595

Now to import this to firebase I would do the following:

users = []*auth.UserToImport
users = append(users, (&auth.UserToImport{}).
    DisplayName("Jon FOO"))

h := hash.SHA256{
    Rounds:     1,
    InputOrder: hash.InputOrderSaltFirst,
res, err := cl.ImportUsers(ctx, users, auth.WithHash(h))
if err != nil {

The user is well imported in firebase (I can see it in the console), but when I try to login, I have this error The password is invalid or the user does not have a password.

I cannot see what is wrong with my way, maybe the Rounds parameter should be updated, but to what value?



I finally found my issue.
In my case I was giving as the PasswordHash the hex representation of the password:


It turns out I have to decode first the password, like the following:

decoded, err := hex.DecodeString("54ccb21d42c6961aa1b666b7cb0485f85aab2f2323399fb2959ea5e4e9f6f595")
if err != nil {
    return err
user := (&auth.UserToImport{}).
    PasswordSalt([]byte("cb60eb29-95a2-418e-be2a-c1c107fb1add")). // the salt stays the same

// call ImportUsers with the same hash configuration (Rounds: 1, InputOrder: SaltFirst)

After updating this I ran the code and I could now authenticate with my imported user.

Quick note: as mentionned in the comment, the node SDK does not have the option to specify the input order (salt or password first), this seems to be an important missing feature.

Answered By – bebenzer

Answer Checked By – Gilberto Lyons (GoLangFix Admin)

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