[Cryptography] Applying the Mesh to do SSH really right

Phillip Hallam-Baker phill at hallambaker.com
Tue Oct 26 16:34:06 EDT 2021

On Tue, Oct 26, 2021 at 3:22 AM Howard Chu <hyc at symas.com> wrote:

> Phillip Hallam-Baker wrote:
> > On Sun, Oct 24, 2021 at 8:40 AM Howard Chu <hyc at symas.com <mailto:
> hyc at symas.com>> wrote:
> >
> >     Phillip Hallam-Baker wrote:
> >     > April King started a thread on Twitter about how to use SSH in the
> enterprise: Why aren't people using the SSH PKI, why do people roll their
> own key
> >     > provisioning scripts knowing these are almost certain to be
> disaster areas?
> >
> >     Good question. Pretty much every pain point you outline here is
> already solved in enterprises by LDAP.
> >     Rolling any other solutions just sounds like pointless protocol
> proliferation.
> >
> >
> > Since a major concern I raised was insider threat and since LDAP is a
> single point of trust, I fail to see how LDAP is remotely relevant.
> You cannot eliminate that central point. You have to give someone
> authority to terminate
> or disable an employee's access. Anyone who can do so can also reset their
> credentials.

Yet the Mesh does exactly that. It is a Threshold Key Infrastructure.

LDAP was a less bad version of X.500 (mostly) developed by Netscape in the
1990s. I am very familiar with it. But it's primary function was to support
the enterprise X.509/PKIX systems being developed by VeriSign and Entrust.
And even then, it was more of a liability than an asset.

> > LDAP does not address the private key management either. All it does is
> provide one means of distributing certs.
> That is false. It can also be used to securely distribute the private
> keys. Painlessly,
> as demonstrated here
> https://twitter.com/hyc_symas/status/851170944345407488

So now you are generating private keys and distributing them to devices.
What is the security model here? How do you authenticate the requests?

If your answer is 'plaintext password to the LDAP directory' then all you
have managed is a downgrade attack reducing a public key authentication
system to a password based one.

> I have never understood what advantage LDAP was
> > supposed to have over some HTTP scheme for that.
> The simple fact that LDAP implementations already come with mature
> security models with
> fine grained authorization and distributed administration makes it far
> more suitable than
> an arbitrary scheme cooked up over HTTP.

So we should give up on computer security research, the problem is already
solved. The fact there is a major breach every week must be an illusion.
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