NIST Compliance

To comply with the latest NIST guidelines TLS 1.2 should have TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256 disabled. I can’t find anyway to do this on Cloudflare.

As much as I’d love to disable a bunch of weaker cyphers, it’s not possible on any of the plans I’m on.

However…I do have a Biz plan where I’ve uploaded my Let’s Encrypt certificate and it’s not using the TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256 cypher. I don’t know if it’s because it’s a Biz plan, or if it’s because of the Let’s Encrypt certificate.

@sdayman assuming the certificate is *RSA
an *ECDSA* cipher wouldn’t show up, so it’s probably due to the Certificate.


Yes it seems that Cloudflare are issuing ECDSA certificates on their free plan, does anyone know if it is possible to have RSA certificate instead without having to jump all the way to a business plan?

Here’s what’s installed on the Pro Plan:

I’m not sure what you get if you buy a Dedicated Certificate.

Unfortunately It is all 3 types and one is selected automatically to suit the client otherwise the Pro package might have been an option as the cost is not too unreasonable. Unfortunately a test for NIST would still fail due to the availability of ECDSA.

It seems that ECDSA was not widely available when the NIST guidelines were written. It seems that it should be OK from a technical stand point of view. The problem seems to be that as the guidelines do not make a recommendation for ECDSA it means that using Cloudflare does not allow us to claim NIST compliance.

That’s what I suspected, which is the same issue I have with the weaker cyphers. Server may select, but it’s still there.

:wave: @darren.grant,

As @sdayman indicated today you’d need to upload your own certificate with the cyphers you want to use or if you are an enterprise customers you can provide Cloudflare a whitelisted set of cyphers to be used through your account team.


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What are the “NIST compliance” rules and why do you want to turn off good cryptography?

I believe this one:

See page 26 for recommended cipher suites. From my test with a universal SSL certificate (ECDSA, RSA, and DSA) it does show some CHACHA cipher suites that aren’t listed (or even mentioned) in the NIST draft.

Note that this is a draft, so comments are open — both (Qualys, Inc) and Carnegie Mellon University (page 12) support that CHACHA20 is a secure cipher, just not an approved cipher. Since this is a draft, the guidelines are not finalized, and CHACHA20 might make it into the final revision.

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