Check user authentication using HTTP Digest auth

def check_digest_auth(user, passwd):
    """Check user authentication using HTTP Digest auth"""

    if request.headers.get('Authorization'):
        credentials = parse_authorization_header(request.headers.get('Authorization'))
        if not credentials:
            return
        request_uri = request.script_root + request.path
        if request.query_string:
            request_uri +=  '?' + request.query_string
        response_hash = response(credentials, passwd, dict(uri=request_uri,
                                                           body=request.data,
                                                           method=request.method))
        if credentials.get('response') == response_hash:
            return True
    return False