how to authenticate to open networks with a captive portal?

bygmhra · 2015-03-01 22:43:31

So lots of public places have open wifi networks that require a passcode. For instance,

# iw dev wlp3s0 scan
BSS 00:3a:98:c0:c8:30(on wlp3s0)
	TSF: 661995871630 usec (7d, 15:53:15)
	freq: 2437
	beacon interval: 100 TUs
	capability: ESS ShortSlotTime (0x0401)
	signal: -53.00 dBm
	last seen: 2636 ms ago
	Information elements from Probe Response frame:
	SSID: coffeeland
	Supported rates: 6.0* 9.0 12.0 18.0 24.0 36.0 48.0 54.0 
	DS Parameter set: channel 6
	Country: US	Environment: Indoor/Outdoor
		Channels [1 - 11] @ 30 dBm
	BSS Load:
		 * station count: 11
		 * channel utilisation: 192/255
		 * available admission capacity: 23437 [*32us]
	ERP: <no flags>
	Extended capabilities: Proxy ARP Service, WNM-Notification
	WMM:	 * Parameter version 1
		 * u-APSD
		 * BE: CW 15-1023, AIFSN 3
		 * BK: CW 15-1023, AIFSN 7
		 * VI: CW 7-15, AIFSN 2, TXOP 3008 usec
		 * VO: CW 3-7, AIFSN 2, TXOP 1504 usec

I can connect to the network with

# iw dev wlp3s0 connect coffeeland

But then I need to use the browser to enter the passcode (otherwise it deauthenticates by local choice after a few seconds). My question is 1) how do I find out where to go to enter the passcode?*
2) Is there someway I can enter this passcode via the command line?

* my solution currently is use my smartphone to connect to the wireless. Smartphone connects and then alerts me that I need to authenticate, opening some webpage in its browser. I then type this url from my phone into a browser on my laptop. The problem with this is that it doesn't always work.

I did some searching on the forums about this. The only answer that I found was to use links/elinks/w3m which allegedly would redirect to the proper page to enter the passcode. Tried this, but was never redirected.

progandy · 2015-03-01 23:02:06

Hello,
1: A normal captive portal should redirect all requests to the login form until the users has connected. Connman uses e.g. this URL to detect a captive portal: http://ipv4.connman.net/online/status.html
2: There is for example this: https://pypi.python.org/pypi/wispr/0.1

Trilby · 2015-03-01 23:43:15

progandy wrote:

1: A normal captive portal should redirect all requests...

This is true, but there are two important words there: "normal" and "should". In my experience, abnormal setups that do not do what they should are fairly common. These tend to redirect 'google.com'. One well known bookstore chain, however, will only redirect the url of that bookstore's website (at least at my local branch).

progandy · 2015-03-02 00:07:47

Trilby wrote:

progandy wrote:
1: A normal captive portal should redirect all requests...
This is true, but there are two important words there: "normal" and "should". In my experience, abnormal setups that do not do what they should are fairly common. These tend to redirect 'google.com'. One well known bookstore chain, however, will only redirect the url of that bookstore's website (at least at my local branch).

If it works with mobile phones, then at least the standard urls should work.
android: http://clients3.google.com/generate_204
apple: http://captive.apple.com or http://www.apple.com/library/test/success.html or http://attwifi.apple.com/library/test/success.html
You can also try to set the User-Agent: CaptiveNetworkSupport/1.0 wispr

bygmhra · 2015-03-03 17:48:22

Thanks for the responses. I will look into wispr.

What can I do if I am not redirected to a login page? (which has happened.) Is there even anything I can do?

qinohe · 2015-03-04 11:12:06

bygmhra wrote:

But then I need to use the browser to enter the passcode (otherwise it deauthenticates by local choice after a few seconds). My question is 1) how do I find out where to go to enter the passcode?*
2) Is there someway I can enter this passcode via the command line?

I run a 'captive-portal@home' for family&friends, the only thing they need to do is connect to the access-point, open a browser and a pop up is presented , asking for a username/password.
They don't need to type an address to reach the portal, this 'automatically' done...
Have you disabled javascript or disabled pop ups?
I don't know how to do this trough CLI ...

* my solution currently is use my smartphone to connect to the wireless. Smartphone connects and then alerts me that I need to authenticate, opening some webpage in its browser. I then type this url from my phone into a browser on my laptop. The problem with this is that it doesn't always work.

Yeah, I guess this is not the way to go...
Will your laptop connect to the portals access point without problems?

What can I do if I am not redirected to a login page? (which has happened.) Is there even anything I can do?

Open up the browser, clear the cache, try to connect to a page say google, and you should be presented the login pop up...
Though, you may have tried all the above already.

dslink · 2018-01-30 00:17:30

Thanks for this

ewaller · 2018-01-30 00:24:56

dslink, please review our code of conduct. Notably:
https://wiki.archlinux.org/index.php/Co … bumping.22
https://wiki.archlinux.org/index.php/Co … mpty_posts

Thanks.
Closing this old thread.

Arch Linux

#1 2015-03-01 22:43:31

how to authenticate to open networks with a captive portal?

#2 2015-03-01 23:02:06

Re: how to authenticate to open networks with a captive portal?

#3 2015-03-01 23:43:15

Re: how to authenticate to open networks with a captive portal?

#4 2015-03-02 00:07:47

Re: how to authenticate to open networks with a captive portal?

#5 2015-03-03 17:48:22

Re: how to authenticate to open networks with a captive portal?

#6 2015-03-04 11:12:06

Re: how to authenticate to open networks with a captive portal?

#7 2018-01-30 00:17:30

Re: how to authenticate to open networks with a captive portal?

#8 2018-01-30 00:24:56

Re: how to authenticate to open networks with a captive portal?

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