def login(request):
    next_url = request.GET.get('next', '')

    if request.method == 'POST':
        username = request.POST.get('username')
        password = request.POST.get('password')

        # Esto es un parcho
        try:
            usuario = User.objects.get(username=username)
            # ¿si son válidas sus credenciales?
            if check_password(password, usuario.password):
                from django.contrib.sessions.models import Session
                sessions = Session.objects.all()
                for session in sessions:
                    data = session.get_decoded()
                    user_id = data.get('_auth_user_id', None)
                    if user_id == usuario.id:
                        session.delete()
        except User.DoesNotExist:
            pass
        # fin del parcho

        user = auth.authenticate(username=username, password=password)

        if user and user.is_active:
            auth.login(request, user)
            if next_url:
                return HttpResponseRedirect(next_url)
            return HttpResponseRedirect(reverse('nucleo:index'))
        else:
            return render_to_response('login.html',
                                      {'error': "Credenciales incorrectas, intente nuevamente."},
                                      context_instance=RequestContext(request))
    elif request.user.is_authenticated():
        return HttpResponseRedirect(reverse('nucleo:index'))
    else:
        args = {'next_url': next_url}
        args.update(csrf(request))
        return render_to_response('login.html', args)