Re: [TLS] tls-external-psk-guidance // Draft for a suggestion of string encoding for manually typing a PSK is available

Hello to all,

in the process of the discussions of the external PSK guidance document,
it was considered to suggest an encoding for PSK for applications that
need to enter the key by manual typing.

Presently such applications might be tempted to allow for strings such
as "banana" as PSK which is considered to be a bad idea.

I have prepared a very rough suggestion, on how an encoding could be
defined that would require assistance from a tool and might enforce some
minimum level of entropy. Moreover such an encoding might be more user
friendly, since a certain level of typing errors could be distinguished
from authentication failures.

A first suggestion as basis for a discussion is now online at

https://datatracker.ietf.org/doc/draft-haase-psk-encoding/

Yours,

Björn.

Am 09.03.2020 um 20:17 schrieb Christopher Wood:
> This document is the first checkpoint for the External PSK design team started a few weeks back. Feedback in the form of comments, edits, or PRs [1] is welcome!
>
> Thanks,
> Chris (no hat)
>
> [1] https://github.com/tlswg/external-psk-design-team
>
> ----- Original message -----
> From: internet-drafts@ietf.org
> To: "Christopher A. Wood" <caw@heapingbits.net>, Mohit Sethi <mohit@piuha.net>, Jonathan Hoyland <jonathan.hoyland@gmail.com>, Christopher Wood <caw@heapingbits.net>, Russ Housley <housley@vigilsec.com>
> Subject: New Version Notification for draft-dt-tls-external-psk-guidance-00.txt
> Date: Monday, March 09, 2020 12:10 PM
>
> A new version of I-D, draft-dt-tls-external-psk-guidance-00.txt
> has been successfully submitted by Christopher A. Wood and posted to the
> IETF repository.
>
> Name:		draft-dt-tls-external-psk-guidance
> Revision:	00
> Title:		Guidance for External PSK Usage in TLS
> Document date:	2020-03-09
> Group:		Individual Submission
> Pages:		11
> URL:            https://www.ietf.org/internet-drafts/draft-dt-tls-external-psk-guidance-00.txt
> Status:         https://datatracker.ietf.org/doc/draft-dt-tls-external-psk-guidance/
> Htmlized:       https://tools.ietf.org/html/draft-dt-tls-external-psk-guidance-00
> Htmlized:       https://datatracker.ietf.org/doc/html/draft-dt-tls-external-psk-guidance
>
>
> Abstract:
>     This document provides usage guidance for external Pre-Shared Keys
>     (PSKs) in TLS.  It lists TLS security properties provided by PSKs
>     under certain assumptions and demonstrates how violations of these
>     assumptions lead to attacks.  This document also discusses PSK use
>     cases, provisioning processes, and TLS stack implementation support
>     in the context of these assumptions.  It provides advice for
>     applications in various use cases to help meet these assumptions.
>
>
>
>
> Please note that it may take a couple of minutes from the time of submission
> until the htmlized version and diff are available at tools.ietf.org.
>
> The IETF Secretariat
>
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