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Comment by throaway920181 | Hacker News Reader

throaway920181

Cool, but hachyderm.io also is not a trusted/recognizable domain for me. Trust issues all the way down!

It's definitionally the correct domain for Simon Tatham's social media. What are you expecting here?

How would the average person know that?

Average person aware of trust on social network / internet - because https://hachyderm.io/@simontatham has a validated link to the author's homepage.

Others - they don't understand the trust anyway, so there prerequisite steps missing before the main question anyway.

hachyderm.io says it has a validated link to his homepage, but if you don't already trust hachyderm.io that means nothing.

It means a lot - you need to check the other side's meta to confirm yourself. https://fedi.tips/how-do-i-verify-my-account/

For example, at https://www.chiark.greenend.org.uk/~sgtatham/ : (the rel=me is the important part)

    [...] <a rel="me" href="https://hachyderm.io/@simontatham"> [...]

No, it really means nothing. Identity on the internet is not a solved problem.

You are wrong.

It means that whoever owns the website marked as verified also owns the social account. See https://joinmastodon.org/verification for a quick overview of how it works.

No, it means a certain link exists on the website. On Hacker News of all sites, I would think we should all know that's not sufficient evidence of identity for an update regarding the source of critical software like a terminal.

Nobody claimed it validates the identity in any way. It validates that the person at the other website confirms it's their social account and the social account matches the other direction. The real identity is not involved here in any way and never was. You're disagreeing with someone nobody here raises.

But the link validation confirms that if you believed that the original download site belongs to the author, then you would have almost the same guarantee about the social account. (+/- the chances of the putty website being hacked)

Yes, your caveat at the end there is exactly why this method shouldn't be trusted, as it's indistinguishable from an attacker with access to embed a single link.

So it doesn't confirm the account belongs to the author, it confirms the site has a specific link and nothing more.

A regular link won't do, since it requires the rel="me" attribute, which is intended for this purpose: https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/...

Adding a <meta> tag or creating a page with certain content are already used even for more impactful verification, like getting issued a certificate for that domain.

If an attacker does have broad access to edit the HTML of your website, I feel that's already the issue and Mastodon verifying that "this person controls this website" isn't even really wrong.

So you have read that page and understand its purpose is to link social media profiles for informational purposes, but don't understand that it's not suitable for any kind of auth, let alone in a software supply chain?

By the XFN spec, it "demonstrates that the same person has control over [the pages]". The docs page I linked links to two further specs for using it for authentication in the way that Mastodon does.

I'm sorry. The XHTML Friends Network rel tag is neither reliable identification nor authentication. It's designed to say "this is my blog" in low stakes environments.

No sane sober person would use it to authenticate messages about changing URLs in a software supply chain.

If an attacker has control over the page to edit arbitrary HTML, that chain is already compromised. Even if the attacker's exploit only allowed certain attributes, just the href and rel attributes needed for this protocol would already be enough to execute javascript and load stylesheets on that page.

This is in addition to the original site linking to the new one with a news post. Does that also mean nothing because an attacker could add a news post to the page?

No, if somebody has access to edit your home page directly, your blog, your company site, etc - you've already lost the game.

How is this any different than your email address being compromised? How is this different than having your laptop compromised and somebody downloading your .ssh folder?

The issue here isn't "is this reliable identification" - because it IS reliable. Your concern is "how likely is this to be compromised vs other things" and that's a fair concern - but there are plenty of very secure web sites out there. This isn't saying "I am john doe and this is my identity", this is saying with some confidence "this person on mastadon is the same person as the person who wrote this web site copy" and that's a totally fine piece of identification for the right context.

A meta tag won't get you a certificate, that's highly misleading.

If A is saying "I'm also B" an B is saying "I'm also A" then you for most purposes you can trust that A and B are the same person, no?

And that's why the fediverse thing is so niche :)

Looks like it's as complicated as a parts inventory system developed in house for a half a million employee company...

There's a link on one side and a meta tag on the other. It's as simple as you can make the validation between two sites. It's not even fediverse-specific really - there were other services doing something similar before.

It's because freedom and correctness is hard. Yeah, most people prefer convenience and would rather someone be the source of authority to do it for them, but people on fediverse are not those kind of people.

If you check the source of the website that it links to [1], on line 168, we have this

<p>I'm on Mastodon as <a rel="me" href="https://hachyderm.io/@simontatham">@simontatham@hachyderm.io</a>.</p>

If you trust that website, then you can be sure that this Mastodon account is the right one.

1. https://www.chiark.greenend.org.uk/~sgtatham/

Sure, but by the time you've verified that, you could also have just visited the PuTTY website (the old/current one) to verify that putty.software is legit.

It was bad enough that we had to tell developers to trust some rando website to download a tool that we'd use to potentially plug in sensitive production usernames + credentials.

A link that looks like this:

https://www.chiark.greenend.org.uk/~sgtatham/putty/latest.ht...

And now they've gone and made it worse by posting some new site and confirming the new link is real on their weird "hachyderm" social media post thing. Yeah, talk about a grey-beard get-off-my-lawn developer screaming at the wind and wanting to make it worse for themselves and their "brand".

> on their weird "hachyderm" social media post thing

At this point tech people should understand what Mastodon is. For their own benefit. It's been years.

10 MM MAU estimated. Not exactly foundational to online discourse.

We're talking in context of Putty which is itself an extremely niche software. But if you think of just the software/tech people - Mastodon is quite an important place.

[flagged]

I just checked his home page: https://www.chiark.greenend.org.uk/~sgtatham/

So… what would be a trusted domain, for you, then?

https://www.chiark.greenend.org.uk/~sgtatham/putty/

Exactly. Which nicely confirms all this by saying:

Latest news

2025-08-14 New website, putty.software

We have a new domain name for the PuTTY website!

...

Which is what the original response linked to. :P

What if someone hacked his site and inserted that news item? Better to visit the guy in person and verify.

What if someone planted the idea of adding a new website for the project while he was asleep?

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