Friday, September 21, 2018

Why EIDRreader fails from behind a tunnel

I create a tunnel from port 8080 of my 127.0.0.1 to their server using:

ssh -L 8080:custlino.example.com:80 johndoe@example.com

In my /etc/hosts I have:

127.0.0.1   custlino

Then I open a browser on http://custlino:8080 to access their server.

I have installed eidreader.

In my browser I then ask to read an id card. The beid protocol handler will be called with a URL that looks like this:

beid://http://custlino:8080/eid/1234-5678-abcd

EIDReader removes the “beid://” prefix and then uses the requests package which in turn uses the socket package which in the end will do something like this:

>>> import socket
>>> url = "custlino"
>>> socket.getaddrinfo(url, 8080)
[(2, 1, 6, '', ('127.0.0.1', 8080)), (2, 2, 17, '', ('127.0.0.1', 8080)), (2, 3, 0, '', ('127.0.0.1', 8080))]

>>> import requests

So EIDReader finally will post to 127.0.0.1.

Maybe I just need to add ‘127.0.0.1’ to ALLOWED_HOSTS on their server? No, this wasn’t a solution. To be continued.