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I strongly dislike the idea of a CA going around revoking certs/keys just because the keys were leaked somewhere. This road (as wished for by the author) is ve

by jand 11y ago

I strongly dislike the idea of a CA going around revoking certs/keys just because the keys were leaked somewhere. This road (as wished for by the author) is very dangerous - it reads to me: "If a software(-bug) or human error allows technically skilled personal to gain access to a private key, all connected keys shall be revoked". This would apply to (possibly) millions of servers with e.g. vulnerable PHP versions or such stuff. So. Torrents Time made a bad move. Why is that a CA-concern? Honestly, tell me.

striking 11y ago
CAs guarantee that their certificates are secure. If they find out that is no longer guaranteed, then the guarantee is broken. Guaranteeing security is... well, why CAs exist. And breaking vulnerable PHP servers is probably a good idea anyway. Then maybe someone might realize that they're incorrectly configured.
willglynn 11y ago
Short answer: because the CA/B forum requires this. See "Baseline Requirements for the Issuance and Management of Publicly-Trusted Certificates, v.1.1.7" section 13.1.5 point 3. https://cabforum.org/wp-content/uploads/BRv1.1.7.pdf https://cabforum.org/wp-content/uploads/BRv1.1.7.pdf Long answer: Certificate authorities provide assurance. In this instance, they received a request from someone asserting "I am localhost.ttconfig.xyz, I have this public key, and I sign this entire statement using my private key". The certificate authorities validated that the requester did in fact control localhost.ttconfig.xyz, then they took the request above, added "I am <Comodo/GeoTrust/thawte>, this certificate reflects the identity and intentions of <subject>, and I sign this entire statement using my private key". Your browser trusts certificate authorities to make statements like these. This trust is not given blindly; it's instead driven by complex procedural machinery. Browser vendors require certificate authorities to do specific things in order to earn and keep the browser's trust. For example, see Mozilla's CA policies: https://www.mozilla.org/en-US/about/governance/policies/security-group/certs/policy/inclusion/ https://www.mozilla.org/en-US/about/governance/policies/secu... The certificate authorities have rules to follow, and they in turn require that their subscribers do certain things so the CA can comply with those rules. One of the requirements CAs make of their customers is that they protect their private key. Why is this important? Well, remember that the CA made a statement that "this certificate reflects the identity and intentions of <subject>". Losing your private key means anyone else can use that certificate, even if they are not you – which makes the CA's statement a lie. CAs are built on trust, so they must revoke it.
- jand 11y ago
  Thank you for the detailed explanation. I was not aware that there were rules enforcing such actions. The linked PDF answers the question why corrupted software stacks do not qualify for forced revocation. Section 10.2.4 (which is the lever for 13.1.5) requires (but not limited to that) a private key to be "communicated" to restricted parties before a revocation might be considered. --> For the small fee of some downvotes i learned that any cloud based service storing private keys for end users qualifies for a revocation - as long as the CA knows about it.
- joelcollinsdc 11y ago
  Perhaps this is a dumb question, but what should the torrent time developers have done differently to have local valid TLS without bundling a private key?
  - ikeboy 11y ago
    Generating a unique key for each installation and adding that to the list of root CAs on that computer.
    - chris_wot 11y ago
      Err... Isn't that what Lenovo did with Superfish? That sounds like terrible advise.
      - ikeboy 11y ago
        No. Lenovo used the same certificate for every computer, and pre installed the software without user consent. Generating a new certificate on the computer it's used on is different.
  - the8472 11y ago
    They don't really need valid TLS in the first place for localhost. At least in firefox Mixed content warnings can be bypassed with custom protocols that declare that they're secure for embedding in secure content.

by jand 11y ago

striking 11y ago

CAs guarantee that their certificates are secure. If they find out that is no longer guaranteed, then the guarantee is broken. Guaranteeing security is... well, why CAs exist. And breaking vulnerable PHP servers is probably a good idea anyway. Then maybe someone might realize that they're incorrectly configured.

willglynn 11y ago

Short answer: because the CA/B forum requires this. See "Baseline Requirements for the Issuance and Management of Publicly-Trusted Certificates, v.1.1.7" section 13.1.5 point 3. https://cabforum.org/wp-content/uploads/BRv1.1.7.pdf https://cabforum.org/wp-content/uploads/BRv1.1.7.pdf Long answer: Certificate authorities provide assurance. In this instance, they received a request from someone asserting "I am localhost.ttconfig.xyz, I have this public key, and I sign this entire statement using my private key". The certificate authorities validated that the requester did in fact control localhost.ttconfig.xyz, then they took the request above, added "I am <Comodo/GeoTrust/thawte>, this certificate reflects the identity and intentions of <subject>, and I sign this entire statement using my private key". Your browser trusts certificate authorities to make statements like these. This trust is not given blindly; it's instead driven by complex procedural machinery. Browser vendors require certificate authorities to do specific things in order to earn and keep the browser's trust. For example, see Mozilla's CA policies: https://www.mozilla.org/en-US/about/governance/policies/security-group/certs/policy/inclusion/ https://www.mozilla.org/en-US/about/governance/policies/secu... The certificate authorities have rules to follow, and they in turn require that their subscribers do certain things so the CA can comply with those rules. One of the requirements CAs make of their customers is that they protect their private key. Why is this important? Well, remember that the CA made a statement that "this certificate reflects the identity and intentions of <subject>". Losing your private key means anyone else can use that certificate, even if they are not you – which makes the CA's statement a lie. CAs are built on trust, so they must revoke it.

jand 11y ago
Thank you for the detailed explanation. I was not aware that there were rules enforcing such actions. The linked PDF answers the question why corrupted software stacks do not qualify for forced revocation. Section 10.2.4 (which is the lever for 13.1.5) requires (but not limited to that) a private key to be "communicated" to restricted parties before a revocation might be considered. --> For the small fee of some downvotes i learned that any cloud based service storing private keys for end users qualifies for a revocation - as long as the CA knows about it.
joelcollinsdc 11y ago
Perhaps this is a dumb question, but what should the torrent time developers have done differently to have local valid TLS without bundling a private key?
- ikeboy 11y ago
  Generating a unique key for each installation and adding that to the list of root CAs on that computer.
  - chris_wot 11y ago
    Err... Isn't that what Lenovo did with Superfish? That sounds like terrible advise.
    - ikeboy 11y ago
      No. Lenovo used the same certificate for every computer, and pre installed the software without user consent. Generating a new certificate on the computer it's used on is different.
- the8472 11y ago
  They don't really need valid TLS in the first place for localhost. At least in firefox Mixed content warnings can be bypassed with custom protocols that declare that they're secure for embedding in secure content.