How come the PQC algos don't show up in the ssh -Q lists

[Roger Grimes]

Ah, thanks for the answers.



Thanks for the reply.



I must have had "mindrot" and wasn't seeing them when I posted this question. But I'm running the queries now and I see them.



-----Original Message-----
From: Theo de Raadt <deraadt at openbsd.org>
Sent: Sunday, July 26, 2026 3:15 PM
To: Roger Grimes <roger at banneretcs.com>
Cc: openssh-unix-dev at mindrot.org
Subject: Re: How come the PQC algos don't show up in the ssh -Q lists



Roger Grimes via openssh-unix-dev <openssh-unix-dev at mindrot.org<mailto:openssh-unix-dev at mindrot.org>> wrote:



> It's my understanding that at least 2-3 of the PQC algorithms (MLKEM768X25519-SHA256, SNTRUP761X25519-SHA512, ML-DSA + Ed25519) are available in OpenSSH now.

>

> But when I run ssh -Q kex or -Q key I don't see them listed.

>

> Should they be listed?



They are definately listed.  If they are not listed, they won't be used.



% ssh -Q kex

...

sntrup761x25519-sha512

sntrup761x25519-sha512 at openssh.com<mailto:sntrup761x25519-sha512 at openssh.com>

mlkem768x25519-sha256

...



MLKEM768X25519-SHA256 is pointless and won't be happening.



sntrup761x25519-sha512 at openssh.com<mailto:sntrup761x25519-sha512 at openssh.com> has been there for YEARS.

mlkem768x25519-sha256 has been there more than a year.



% ssh -Q key-sig

...

ssh-mldsa44-ed25519 at openssh.com<mailto:ssh-mldsa44-ed25519 at openssh.com>

ssh-mldsa44-ed25519-cert-v01 at openssh.com<mailto:ssh-mldsa44-ed25519-cert-v01 at openssh.com>

...



ssh-mldsa44-ed25519 at openssh.com<mailto:ssh-mldsa44-ed25519 at openssh.com> is very new.  The code existed, but was not enabled in the current release.  It was enabled after the last release on 2026/07/09, and will be in the next release.





It is vaguely possible you are running an ssh derivative that is patching them out due because they are misguided.