Capturing digest authentication credentials possible?

I have set up a lighttpd server on port 80, setup mitmproxy in transparent mode and redirected the ip rules from port 80 to 8080. While mitmproxy captures the request headers, the entered passwords are totally invisible to it. As I understand, mitmproxy should be able to intercept them, as they reach the server as plain text, before being encoded. Is it actually possible to achieve?