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by jis 2205 days ago
It's actually worse. The new root (good I believe until 2038) uses the same key as the now expired certificate. It has to or it would not be possible to validate the certificates that were issued. And this new one is a root certificate installed in browsers!

What "should" happen is that no certificate should be issued with an expiration date later than the issuing certificate. Then as the issuing certificate gets closer to expiration, a new one, with a new key pair, should be created and this new certificate should sign subordinate certificates.
1 comments
jis 2205 days ago
Sorry to reply to my own comment. But I want to clarify. Two certificates (at least) expired. The root named "AddTrust External CA Root" and a subordinate certificate with a subject of "USERTrust RSA Certification Authority." Both expired around the same time.

The "USERTrust RSA Certification Authority" certificate signed yet another layer of intermediate certificates.

The "USERTrust RSA Certification Authority" certificate was promoted to a self-signed certificate, now in the browser trust stores, using the same key pair as the original certificate that was signed by "AddTrust External CA Root." It has an expiration of 2038 (although that concept is a bit vague in a root certificate).

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josephcsible 2205 days ago
There's actually a third certificate for "USERTrust RSA Certification Authority", also using the same key pair, signed by a different root called "AAA Certificate Services". It looks like the intended replacement for the expiring one is this one, rather than the one where it's the root itself.
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dylz 2205 days ago
It is explicitly not a replacement, but some kind of legacy fallback that they don't want you to use, but exists for enterprise customers that absolutely can't get trust.
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josephcsible 2205 days ago
Are you sure? That's the path that InCommon has been providing me for new certificates since they switched away from the expiring one.
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dylz 2205 days ago
On anything with a modern TLS stack, I see this trust chain:

- Leaf cert (your cert)

- InCommon RSA Server CA

- USERTrust RSA Certification Authority (this is/should be the final point)

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josephcsible 2205 days ago
That's what my browser shows me too, but it's just because it's ignoring the cross-signed one that chains to AAA. The server is sending it, per InCommon's setup instructions.
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