def _auth(profile=None):
    '''
    Set up neutron credentials
    '''
    if profile:
        credentials = __salt__['config.option'](profile)
        user = credentials['keystone.user']
        password = credentials['keystone.password']
        tenant = credentials['keystone.tenant']
        auth_url = credentials['keystone.auth_url']
        region_name = credentials.get('keystone.region_name', None)
        service_type = credentials.get('keystone.service_type', 'network')
        os_auth_system = credentials.get('keystone.os_auth_system', None)
        use_keystoneauth = credentials.get('keystone.use_keystoneauth', False)
        verify = credentials.get('keystone.verify', True)
    else:
        user = __salt__['config.option']('keystone.user')
        password = __salt__['config.option']('keystone.password')
        tenant = __salt__['config.option']('keystone.tenant')
        auth_url = __salt__['config.option']('keystone.auth_url')
        region_name = __salt__['config.option']('keystone.region_name')
        service_type = __salt__['config.option']('keystone.service_type')
        os_auth_system = __salt__['config.option']('keystone.os_auth_system')
        use_keystoneauth = __salt__['config.option']('keystone.use_keystoneauth')
        verify = __salt__['config.option']('keystone.verify')

    if use_keystoneauth is True:
        project_domain_name = credentials['keystone.project_domain_name']
        user_domain_name = credentials['keystone.user_domain_name']

        kwargs = {
            'username': user,
            'password': password,
            'tenant_name': tenant,
            'auth_url': auth_url,
            'region_name': region_name,
            'service_type': service_type,
            'os_auth_plugin': os_auth_system,
            'use_keystoneauth': use_keystoneauth,
            'verify': verify,
            'project_domain_name': project_domain_name,
            'user_domain_name': user_domain_name
        }
    else:
        kwargs = {
            'username': user,
            'password': password,
            'tenant_name': tenant,
            'auth_url': auth_url,
            'region_name': region_name,
            'service_type': service_type,
            'os_auth_plugin': os_auth_system
        }

    return suoneu.SaltNeutron(**kwargs)