The oddities of the implementation of Wi-Fi in the Moscow metro
In early 2015, free Wi-Fi was fully launched in the Moscow metro. I went to test it and found some oddities. For example, for some reason, the redirect to the captive portal on iOS devices was broken. The fact is that when connected to Wi-Fi, iOS devices and desktop MAC OS send HTTP GET requests to their sites to check if there is a redirect. Requests are sent from the User-Agent
CaptiveNetworkSupport-306.3.1wispr
In this case, each time substituting a random URI.
A typical query looks like this: ')
curl --http1.0 -A "CaptiveNetworkSupport-306.3.1 wispr" http://www.appleiphonecell.com/Aw0ac99O0Ede/5fnWgqV480Rh/6ZE3jFoingFF/vYBzRnGJgh54/dS9hZn2rVO3M.html
In response, the expected string "Success". If the content of the page differs from the expected, the system considers that there is a stub in the network and opens it on top of all windows.
For some reason, these requests are specifically intercepted, so that the system thinks there is no redirect.