This issue for identity-platform but there is no public tracker that I can select so I write it here, please forward it to there tracker if any

What is the issue?

Giving this ref: https://cloud.google.com/identity-platform/docs/migrating-users

I want to migrate users with SHA1 algorithm, the hash created like (pass + salt)

It didn't work, i think because you are assuming the hash created like (salt+pass)

What could be a solution?

I wish to have the option to specify hash-input-order like firebase see https://firebase.google.com/docs/cli/auth#auth-import

So I can pass passwordHashOrderwiht the hash options like:

admin
  .auth()
  .importUsers(
    [
      {
        uid: 'some-uid',
        email: 'user@example.com',
        // Must be provided in a byte buffer.
        passwordHash: Buffer.from('password-hash'),
        // Must be provided in a byte buffer.
        passwordSalt: Buffer.from('salt'),
      },
    ],
    {
      hash: {
        algorithm: 'SHA1',
        rounds: 1,
        passwordHashOrder: 'PASSWORD_AND_SALT'
      },
    }
  )
  .then((results) => {
    results.errors.forEach((indexedError) => {
      console.log(`Error importing user ${indexedError.index}`);
    });
  })
  .catch((error) => {
    console.log('Error importing users :', error);
  });