[TLS] Doubts in draft-ietf-tls-rfc4492bis

Raja ashok <raja.ashok@huawei.com> Mon, 24 July 2017 13:48 UTC

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From: Raja ashok <raja.ashok@huawei.com>
To: "draft-ietf-tls-rfc4492bis@ietf.org" <draft-ietf-tls-rfc4492bis@ietf.org>, "ynir.ietf@gmail.com" <ynir.ietf@gmail.com>, "simon@josefsson.org" <simon@josefsson.org>, "mpg@elzevir.fr" <mpg@elzevir.fr>
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Thread-Topic: Doubts in draft-ietf-tls-rfc4492bis
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Date: Mon, 24 Jul 2017 13:48:13 +0000
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Subject: [TLS] Doubts in draft-ietf-tls-rfc4492bis
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Hi Nir, Josefsson & Pegourie,

As per section 5.2 server should send only "Supported Point Format" extensions in server hello message. And it doesn't require to send "Supported Elliptic Curve" extensions. Because of this if server is supporting only few Curves and if it receives unsupported Elliptic curve in client certificate message, then server might not be able to continue the handshake.
This makes (D)TLS server should mandatory implement all the curves mentioned in "NamedCurve". But I feel mandating (D)TLS server to support all NamedCurve is not feasible, as in future if new named curves are defined then updating legacy server is not easy. And also constraint (D)TLS server generally doesn't support all the curves.
Please provide your suggestion on this. If my understanding is wrong, please correct me.



Raja Ashok V K
Huawei Technologies
Bangalore, India
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