Re: [TLS] Moving SHA-1 signature schemes to not recommended in draft-ietf-tls-md5-sha1-deprecate

Sean Turner <> Fri, 18 September 2020 14:28 UTC

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From: Sean Turner <>
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Date: Fri, 18 Sep 2020 10:28:23 -0400
Cc: Joe Salowey <>, TLS List <>, Benjamin Kaduk <>, "" <>
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To: "Salz, Rich" <>
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Subject: Re: [TLS] Moving SHA-1 signature schemes to not recommended in draft-ietf-tls-md5-sha1-deprecate
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Just to close the loop on this, there are three values: Y, N, and blank. I tend to think we should mark is as “N”:

   If an item is not marked as "Recommended" (i.e., "N"), it does not
   necessarily mean that it is flawed; rather, it indicates that the
   item either has not been through the IETF consensus process, has
   limited applicability, or is intended only for specific use cases.

That specific use case is two servers talking an old version to each other in whatever setting they are being used in.

Also, should we be adding “_legacy” to the names of the code points as was done for rsa_pkcs1_sha256_legacy by:


> On Jun 25, 2020, at 08:35, Salz, Rich <> wrote:
> 	• I submitted a PR [1] for draft-ietf-tls-md5-sha1-deprecate to move the recommended IANA registry entries for  rsa_pkcs1_sha1 and ecdsa_sha1 in the Signature Scheme registry from Y to N.   This change can be incorporated with any updates from the AD review.  
> Yes yes yes.
> Or no no no?
> I think it is remove the “Y” and leave blank, right?
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