It’s such a product of “Ooh! Markup languages! What can we use a markup language to solve!” When authentication is just not a document or data stream that needs marked-up.
The article rightly connects this to XML, which was indeed the hammer to everything’s nail at the time
I think we aren’t done with this problem yet, though. OIDC makes a lot of assumptions in service to Google and others. And tailscale as mentioned, despite “holding the line,” already reveals the cracks when things like GitHub accounts have to be treated differently from others.
What we are missing is a provider-independent way to do this. I should be able to create an account and log in just about anywhere using a backend I control. It can be done, but not with what we have today
As the article points out, it's not really fair to criticize SAML for not using JSON, given that JSON barely existed at the time.
If you needed a serialized representation of structured data, I think it made engineering sense to use XML even if it was more featureful than you needed. The alternatives were ASN.1 or rolling your own format from scratch. It's not at all obvious that those are better.
(You could argue in favor of rolling your own format on the grounds that it wouldn't be vulnerable to XML-specific security problems, but I don't think those problems were fully appreciated at the time. If they had been, probably people would have come up with some kind of quasi-standardizable secure XML variant that just disables the specific features that cause those problems.)
I agree that XML (even without the security-relevant misfeatures) is worse than JSON or other non-markup-language serialization formats for the majority of use cases that don't need a markup language, but this is not a big problem, it's basically just syntax.
I think ASN.1, specifically DER, actually would have been better because it avoids the canonicalization problems saml has, as well as the general XML problems like XXE.
jmbwell · · focus · HN ↗
The article rightly connects this to XML, which was indeed the hammer to everything’s nail at the time
I think we aren’t done with this problem yet, though. OIDC makes a lot of assumptions in service to Google and others. And tailscale as mentioned, despite “holding the line,” already reveals the cracks when things like GitHub accounts have to be treated differently from others.
What we are missing is a provider-independent way to do this. I should be able to create an account and log in just about anywhere using a backend I control. It can be done, but not with what we have today
ameliaquining · · focus · HN ↗
If you needed a serialized representation of structured data, I think it made engineering sense to use XML even if it was more featureful than you needed. The alternatives were ASN.1 or rolling your own format from scratch. It's not at all obvious that those are better.
(You could argue in favor of rolling your own format on the grounds that it wouldn't be vulnerable to XML-specific security problems, but I don't think those problems were fully appreciated at the time. If they had been, probably people would have come up with some kind of quasi-standardizable secure XML variant that just disables the specific features that cause those problems.)
I agree that XML (even without the security-relevant misfeatures) is worse than JSON or other non-markup-language serialization formats for the majority of use cases that don't need a markup language, but this is not a big problem, it's basically just syntax.
thayne · · focus · HN ↗