[HN Gopher] Pwned Certificates on the Fediverse
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       Pwned Certificates on the Fediverse
        
       Author : JNRowe
       Score  : 78 points
       Date   : 2024-01-15 23:19 UTC (2 days ago)
        
 (HTM) web link (www.hezmatt.org)
 (TXT) w3m dump (www.hezmatt.org)
        
       | hunter2_ wrote:
       | > I stopped sending compromised key notifications to CAs.
       | Instead, now I'm publishing the details of compromised
       | certificates to everyone, so that users can protect themselves
       | directly
       | 
       | If this is most feasible, ok, though it smells like the opposite
       | of responsible disclosure. Perhaps I'm just not in tune with the
       | nature of how this threat differs from a typical software
       | vulnerability, and therefore the responsible disclosure method
       | I'm familiar with is irrelevant.
        
         | doesnt_know wrote:
         | The surrounding text explains that several CAs didn't like
         | having to spend resources doing revocations and intentionally
         | made the disclosure process more onerous.
         | 
         | Responsible disclosure is a courtesy that should not be
         | extended to bad faith actors.
        
         | profmonocle wrote:
         | > though it smells like the opposite of responsible disclosure
         | 
         | He's not sharing the key itself, just proof that it's been
         | leaked. Unlike disclosing a security issue without warning,
         | this disclosure doesn't give any bad actors and power they
         | didn't already possess. (Because any bad actors who _have_ the
         | key would already know what TLS certs it matches, or could
         | trivially find out by querying CT logs themselves.)
        
           | hunter2_ wrote:
           | Thank you!
        
           | hsbauauvhabzb wrote:
           | Even with the key, from what I can tell it's fairly hard to
           | exploit for the average netizen.
        
       | profmonocle wrote:
       | > However, several CAs disliked having to revoke all those
       | certificates, because it cost them staff time (and hence money)
       | to do so. They went so far as to change their procedures from the
       | standard way of accepting problem reports (emailing a generic
       | attestation of compromise), and instead required CA-specific
       | hoop-jumping to notify them of compromised keys.
       | 
       | Maybe the baseline requirements need to be updated to require an
       | automated mechanism for reporting key compromises. CAs have to
       | revoke certs with compromised keys, but by _going out of their
       | way_ to increase the barrier to doing so, they 're clearly not
       | complying in good faith.
       | 
       | The ACME protocol (Let's Encrypt) makes this simple - just sign a
       | request to the revocation API with the cert's private key.
        
         | hsbauauvhabzb wrote:
         | I'm unsure what part of revoking certificates is labor
         | intensive if you're a certificate authority, given your entire
         | purpose is to sign and revoke keys..
        
       | hardcopy wrote:
       | WTF? CAs should be mandated to have an automated, public form/API
       | where you can submit a private key to have it revoked.
       | 
       | Lets encrypt has this.
       | https://letsencrypt.org/docs/revoking/#using-the-certificate...
        
         | pquerna wrote:
         | The API for Let's Encrypt to do this requires possession of the
         | private key, which pwned keys doesn't always have. Sometimes
         | they just have an "attestation" of compromise:
         | 
         | https://pwnedkeys.com/submit.html
         | 
         | Which if you had an standardized representation of that
         | attestation, maybe CAs could consume that instead.
         | 
         | But, the author of pwnedkeys thought of that, and started an
         | RFC for exactly that:
         | 
         | https://github.com/pwnedkeys/key-compromise-attestation-rfc/...
         | 
         | But it seems dead right now.
        
       | ziddoap wrote:
       | > _However, several CAs disliked having to revoke all those
       | certificates, because it cost them staff time (and hence money)
       | to do so. They went so far as to change their procedures from the
       | standard way of accepting problem reports (emailing a generic
       | attestation of compromise), and instead required CA-specific
       | hoop-jumping to notify them of compromised keys._
       | 
       | It would have been nice to have names be named. This is obviously
       | in bad faith, and the bad actors should be called out.
       | 
       | Given that Matt Palmer is an active participant of the MDSP
       | (Mozilla Dev Security Policy) mailing list, I am surprised that I
       | don't recall seeing discussion about this pop up, although I may
       | have missed it. The CAs acting this way really should have to
       | explain themselves.
        
         | Animats wrote:
         | So the Fediverse should blacklist those CAs.
        
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       (page generated 2024-01-18 23:00 UTC)