$credentials = $request->only('Email', 'Password');

// Try hashed login
if (!Auth::attempt($credentials)) {
  $user = User::where('Email', $credentials['Email'])->first();

  // Hashed login failed, attempt legacy (sha256) login and convert if successful
  if ($user->Password == hash('sha256', $credentials['Password'])) {

      $user->Password = Hash::make($credentials['Password']);
      $user->save();

      Auth::login($user);
  } else {
      return response()->json([
          'message' => 'The credentials you entered were incorrect',
      ], 401);
  }
} else {
  return redirect()->intended('dashboard');
}