MIME-Version: 1.0
From: Xuelei Fan <xuelei.fan@vimino.com>
Date: Tue, 20 Jun 2017 17:10:00 -0700
Message-ID: <CAAgBOhsQT78JrWA6VRx158wOE0gR-VOFawcuvqjwopebDcGA2A@mail.gmail.com>
To: "tls@ietf.org" <tls@ietf.org>
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Archived-At: <https://mailarchive.ietf.org/arch/msg/tls/D01Iy32HrFianCA3pKaSt26_hJU>
Subject: [TLS] The use of "trusted_ca_keys" for server certificate selection
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Hi,

In section 4.4.2.2, "Server Certificate Selection", of TLS 1.3 draft:
   https://tools.ietf.org/html/draft-ietf-tls-tls13-20#section-4.4.2.2

It is stated:

   -  The "server_name" and "trusted_ca_keys" extensions [RFC6066
<https://tools.ietf.org/html/rfc6066>] are
      used to guide certificate selection.  As servers MAY require the
      presence of the "server_name" extension, clients SHOULD send this
      extension, when applicable.

The "trusted_ca_keys" extension is not used in TLS 1.3, and is replaced
with the "certificate_authorities" extension (Section 4.2.4):

   The "trusted_ca_keys" extension, which serves a similar purpose
   [RFC6066 <https://tools.ietf.org/html/rfc6066>], but is more
complicated, is not used in TLS 1.3 (although
   it may appear in ClientHello messages from clients which are offering
   prior versions of TLS).


I guess it is a typo or a missed update to use the the "trusted_ca_keys"
extension for server certificate selection in section 4.4.2.2.  The
"certificate_authorities" extension should be used instead.

Regards,
Xuelei Fan

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<div dir=3D"ltr">Hi,<div><br></div><div>In section 4.4.2.2, &quot;Server Ce=
rtificate Selection&quot;, of TLS 1.3 draft:</div><div>=C2=A0 =C2=A0<a href=
=3D"https://tools.ietf.org/html/draft-ietf-tls-tls13-20#section-4.4.2.2">ht=
tps://tools.ietf.org/html/draft-ietf-tls-tls13-20#section-4.4.2.2</a><br></=
div><div><br></div><div>It is stated:</div><div><pre class=3D"gmail-newpage=
">   -  The &quot;server_name&quot; and &quot;trusted_ca_keys&quot; extensi=
ons [<a href=3D"https://tools.ietf.org/html/rfc6066" title=3D"&quot;Transpo=
rt Layer Security (TLS) Extensions: Extension Definitions&quot;">RFC6066</a=
>] are
      used to guide certificate selection.  As servers MAY require the
      presence of the &quot;server_name&quot; extension, clients SHOULD sen=
d this
      extension, when applicable.</pre></div><div>The &quot;trusted_ca_keys=
&quot; extension is not used in TLS 1.3, and is replaced with the &quot;cer=
tificate_authorities&quot; extension (Section 4.2.4):<br></div><div><pre cl=
ass=3D"gmail-newpage">   The &quot;trusted_ca_keys&quot; extension, which s=
erves a similar purpose
   [<a href=3D"https://tools.ietf.org/html/rfc6066" title=3D"&quot;Transpor=
t Layer Security (TLS) Extensions: Extension Definitions&quot;">RFC6066</a>=
], but is more complicated, is not used in TLS 1.3 (although
   it may appear in ClientHello messages from clients which are offering
   prior versions of TLS).</pre></div><div><br></div><div>I guess it is a t=
ypo or a missed update to use the the &quot;trusted_ca_keys&quot; extension=
 for server certificate selection in section 4.4.2.2.=C2=A0 The &quot;certi=
ficate_authorities&quot; extension should be used instead.</div><div><br></=
div><div>Regards,</div><div>Xuelei Fan</div><div><pre class=3D"gmail-newpag=
e"><br></pre></div><div><pre class=3D"gmail-newpage"><br></pre></div></div>

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