XMPP Service Operators - 2020-08-31

Can we get rid of passwords already and use public key authentication?

I’d be all in, if we hide it from the users :)

Wouldn't that require client devs to integrate authentication agents and users to remember longer passphrases?

kikuchiyo, no, why? tie the private key to the device.

passphrase optional.

on mobile OSes, that would be reasonably secure, since apps can’t read each other’s storage

(or you can even put it in the OSes secret vault)

breaks down on standard desktop OSes of course, but who uses those anyways.

Ok, what does this mean for multiple or lost devices?

different private key for each device, obviously

because of that, you can revoke access for lost devices easly

if you lost all devices, you’ll need an out-of-band recovery mechanism, just as if you lost your password

I strongly disagree

You have strong crypto auth

And then you add a backdoor

It's up to the user not to have a backup key hidden somewhere

of course

because user’s are good at that!

And in worst case they don't, they could go to their hosting provider showing physical ID and having someone who knews them add in a new key

which is *exactly* the kind of out-of-band recovery mechanism I’m talking about?

what’s your problem then?

I thought you meant automated

» just as if you lost your password

of course automated for any non-terrible-UX service

Strongly disagree

for terrible-UX-but-high-security services you’d not do that automated obviously.

I'm really tired of having to use software design for morons

sorry to hear

I know what it means to use unbreakable crypto when i turn it on

A lot of companies like to assume their users are stupid and add all kinds of backdoors into the crypto

Calling them recovery

So like you have 2fa, but you can guess someone's pet name or look up their mother's name

And bypass the security

I can auth to IRC servers with a client certificate

Shouldn't that be possible with XMPP as well?

Instead of having to remember passwords

Keeping a bunch of passwords in a database

Take wireguard for example of doing authentication right and and making simple

https://www.wireguard.com/

wireguard is too simple for some use-cases though

anything road-warrior-corporate-type for example.

I use it on my laptop

It's perfectly adequete

> different private key for each device, obviously New devices would need to be cross signed from an already known device, yes?

> jonas’> because of that, you can revoke access for lost devices easly Because of that, you can race to revoke access for lost devices easily. FTFY

?

Since the lost device would probably have the same authz

kikuchiyo, "signed", or simply one-time authenticated with a "device invite" link

pep., removing devices could require a second factor

And you probably just lost it :/

Andotp on the lost mobile 😁

Revocation is annoying

> kikuchiyo, "signed", or simply one-time authenticated with a "device invite" link One-time authentication leads to a race of one-time revokation. How about not revoking a device, but revoking the compromised identity?

You don't get rid of the race do you

pep.: Since there is no continuity, you would need to reestablish trust for a new one.

That also means at any time, somebody (with the right authz, e.g., stolen device) can revoke your perfectly valid identities

(and 2FA on the stolen mobile device, because that's how things work nowadays :p)

Which comes down to meeting in real life or using 2fa.

meeting in real life with whom?

The server operator?

(I haven't read the past few days of logs)

Those to whom you want to communicate with.

Assuming you can also still login first

Password is unchanged, etc.

> Assuming you can also still login first No, assuming that the other party knows you in person and can verify that in real life. The underlying philosophical problem is: _What is identity_ One answer to that could be: A common history.

I meant, you might not have access to your account anymore

In this case surely you can create a new account/identity and get this one acked

Unless you manage to convince the operator that it's your account

pep.: Yes a comprised account is a compromised virtual identity. So there is nothing left than to refer to a second identity, e.g. the real life identity, to establish new trust.

You just need to make sure that the old identity gets revoked completely.

And I'm saying that's the hard part. First if you don't control the account anymore, either you need to regain control of it through the operator, or you need to go through all your contacts and revoke it out-of-band (by meeting IRL)

You don't "just" revoke an identity

🤦🏼‍♂️

What is it Maranda, your hand smells nice? :P

They smell of disinfectant like everyone's, if they're good childs that is pep.

pep.: I know this is not the usual way of thinking about revokation. > you need to go through all your contacts and revoke it out-of-band (by meeting IRL) Or by enabling whomever has gained control over the old identity (including yourself) to destroy it and all of the attached keys, but not to initiate a new one without meeting IRL or 2fa.

Yes and that person in control of your old identity might have no interest in destroying it :p

(or it might be exactly their goal: DoS)

pep.: One person in control has to be able to hit the kill switch for the identity - that would be you. If the attacker does that he looses control. This is a like a remote mechanism to dye stolen money.

Well "Availability" is also part of CIA

Anyone from anonym.im here? ✏