purpose of xp extensions

[Adam Bishop]

On 28 Jun 2018, at 16:48, d tbsky <tbskyd at gmail.com> wrote:
> 1. is the "xp" extensions means windows xp or something?

They were introduced with Windows XP.

> 2. is xp extensions only useful if we want client to verify server certificate?

No, the Windows supplicant will flat out not work without the OIDs being present.

> 3. if we use certificate like let's encrypt without xp extensions.
> what function do we miss? I know it is not very secure to use public
> CA, but it seems easier when deal with mobile devices bring by users.
> they just want to access wifi with their active directory
> username/password.

Don't do this - it's insecure if you allow users to use TOFU with a public CA, and has no advantage over a private CA from a UX perspective. Users will still be prompted to accept the certificate manually even if you obtain it from a public CA.

Adam Bishop

  gpg: E75B 1F92 6407 DFDF 9F1C  BF10 C993 2504 6609 D460

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