How to make iOS forgetting a proxy credential?

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How to make iOS forgetting a proxy credential?

I have a problem with http proxy settings in wifi profile (iPhone 5 - iOS 9.3.3). It seems iOS is keeping the last valid http proxy credential somewhere, despite that I have removed it from the http proxy settings in my wifi profile. Below is the chronology:

I entered credential Test01 and it's successfully connect to the internet - and the log in proxy server shows Test01
I removed the http proxy credential in the wifi profile and disabled the button for authentication. The logic here, it shouldn't be able to connect to the internet as there is no credential provided, but it turns out iPhone still able to connect to the internet. I checked to the proxy server log it still using credential Test01.
I changed the credential to Test02 and it's successfully connect to the internet again - and the log in proxy server shows Test02
I removed the http proxy credential in the wifi profile and disabled the button for authentication again, but iPhone still able to connect to the internet - and from the proxy server log it shows using Test02

Tried resetting network settings but the last valid credential is still remembered.

Is this an expected behaviour? Please advise. Thanks

iPhone 5, iOS 9.3.3, null

Posted on Aug 4, 2016 8:55 PM

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Answer 1

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Fat-man

Level 1

4 points

Sep 20, 2016 1:49 PM in response to randms26

I guess you could just wipe the device.

Definitely not expected. A poorly designed host network, particularly with regard to internet connectivity can cause these symptoms (and many other quirky experiences).

In a poorly designed network this issue is common to IOS 9.x but can also occur on older or newer IOS versions in much small occurrences.

To help understand how Apple devices find and update credentials refer to:

https://developer.apple.com/library/content/documentation/Networking/Conceptual/ CFNetwork/CFHTTPAuthenticationTasks/CFHTTPAuthenticationTasks.html

Remember certificate based WiFi physical layer uses performs authentication (which is https). When a http proxy auth is performed with the new user that saved credential is updated. But because the next https request that would ordinarily auth on https proxy is pathing differently to http and/or that original wifi certificate ssl auth being successful - results in the device thinking the https object is deemed to have already been "accepted" and therefore never updated.

So you may find hybrid credentials being played.

You may also experience random auth prompts with fail https.

Autoproxy and proxy chaining are also in play, as well as the proxy load balancing method and if any surrogate credentials are in play.

It's quite a complex scenario that Apple would not have expected to handle. I suggest you speak to your network design or administrators.

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