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<span style="color: rgb(0, 0, 0); font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt;">The SKI is useful to quickly search for certificates with the same key.</span><br>
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Is saving a few bytes a sufficient reason to 'deviate' from RFC 5280, where we try to get everyone to focus on RFC 5280 adherence at the same time?</div>
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Are we sure that this would not cause any client incompatibility issues? Almost<span style="background-color:rgb(255, 255, 255);display:inline !important" class="ContentPasted2"> all certificates include the SKI today and while this might be fine for the major
browsers, we also know that there are other clients/libraries that interact with web websites.</span></div>
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Paul</div>
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<div id="divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" style="font-size:11pt" color="#000000"><b>From:</b> Hubert Chao <hchao@google.com><br>
<b>Sent:</b> Thursday, December 1, 2022 15:59<br>
<b>To:</b> Lahtiharju, Pekka <pekka.lahtiharju@teliacompany.com>; CA/Browser Forum Validation SC List <validation@cabforum.org><br>
<b>Cc:</b> Aaron Gable <aaron@letsencrypt.org>; Paul van Brouwershaven <Paul.vanBrouwershaven@entrust.com><br>
<b>Subject:</b> [EXTERNAL] Re: [cabf_validation] RFC 5280 conflict for SKI in subscriber certificates</font>
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<div dir="ltr">On Thu, Dec 1, 2022 at 5:21 AM Lahtiharju, Pekka via Validation <<a href="mailto:validation@cabforum.org" target="_blank">validation@cabforum.org</a>> wrote:<br>
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<p class="x_MsoNormal">I support Paul’s idea to change this to SHOULD. Why should we create new recommendations against RFC when this extension is useful in several use cases and almost everybody is using it now.</p>
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<div>Could you list out the use cases where this extension is useful for a TLS certificate? The discussion that Corey linked to (<a href="https://urldefense.com/v3/__https://lists.cabforum.org/pipermail/validation/2021-July/001672.html__;!!FJ-Y8qCqXTj2!bhb6QGSEpqEOi6JyHDzixLHA_ziEpOs6UQYkMiffRA4PH_9fFgyIiZRW3epCZqq0_V5K5pDehK6XTaH3PNBz1ibt$" target="_blank">https://lists.cabforum.org/pipermail/validation/2021-July/001672.html</a>)
specifically says "... a TLS certificate [SKI] should not be needed ... ".</div>
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<div>/hubert </div>
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