6 ms·

That would open a new vector of attack where an attacker would simply have to compromise any of your previous certs; not necessarily an easy feat but still a ne

That would open a new vector of attack where an attacker would simply have to compromise any of your previous certs; not necessarily an easy feat but still a new vector

mehrdadn 6y ago
No it doesn't? All that happens is the previous cert would be accepted with a milder warning for a few weeks (not permanently) after you get a new one. It's just a small grace window to let users still be able to use the site. Just like an expiration date on your milk. There's no need to toss it out immediately just because an extra nanosecond passed.
- lilyball 6y ago
  This would require everyone to understand that previous certs still require high-security for at least a few weeks post expiration. This is not something we can rely on people understanding.
  - im3w1l 6y ago
    Allowing bypass is the old way of doing things, and many non-browsers still allow it, so you should ideally hold on to old certs indefinitely, but at least for a short while.
  - deleted 6y ago
    [deleted]
  - darkerside 6y ago
    I think this is reasonable for people dealing with SSL, like expecting a mechanic to know you change an oil filter when you change the oil.
  - zeroimpl 6y ago
    I'm pretty sure that most people, upon having one of their certs expire, do not find the private key and release it publicly. In fact they often generate a new cert from the same key...
  - bendbro 6y ago
    Alternatively we could have people understand all certificates, regardless of expiration, are high security. Is there any reason someone would want to publicize an expired certificate? Additionally, I can think of a few existing reasons someone would avoid publicizing an expired certificate.
- bawolff 6y ago
  Training users that "mild" warnings can be ignored is very bad for security, as users have trouble differentiating severity. Hsts does not even give users a choice because nobody could come up with a scary enough warning.
  - mehrdadn 6y ago
    I'd argue the problem might be the opposite: people are willing to differentiate on some matters (not everything), but security folks fail to help them do so. They treat every warning like DEFCON 1, as if an expired certificate is remotely similar to a compromised one. People already understand expiration dates aren't exact. They deal with it in all kinds of places. It's not a new concept.
    - bawolff 6y ago
      So what exactly do you want changed? A warning already comes up explaining what happened that a user can click through. Unless the website has opted into strict mode, in which case warnings cannot be bypassed, which seems very reasonable. > People already understand expiration dates aren't exact. They deal with it in all kinds of places. It's not a new concept. Try crossing the border with an expired passport and see how non-exact expiry dates are.
      - mehrdadn 6y ago
        > So what exactly do you want changed? A warning already comes up explaining what happened that a user can click through. Unless the website has opted into strict mode, in which case warnings cannot be bypassed, which seems very reasonable. I'm saying load the website by default; just display a warning that isn't too intrusive or alarming. As a starting point (not suggesting this is peak UX; it's just a starting point for the discussion): it could be just a small balloon notification on the padlock with black text, nothing in red or otherwise alarming (or maybe becoming more red as more time has passed). A little bit like the balloon Chrome displays for "Disable developer-mode extensions". It still lets you use the browser but also gets its point across. > Try crossing the border with an expired passport and see how non-exact expiry dates are. You couldn't think of expiration dates for things that aren't at the extreme? Maybe for actions whose gravity is a little bit more comparable to visiting a website than, say, crossing an international border?
stefan_ 6y ago
In a world where you can simply compromise a cert of your choice we can get rid of the TLS theatre altogether. No, the world we have is one where these expiry mishaps happen all the time, and everyone would be better served if certs had a warning expiration date in addition to the red alert one. It's the old "don't delete a customer the second they are late on a single payment" thing that everyone long recognizes as good practice.
- bawolff 6y ago
  A difference is non expired compromised certificates are usually revoked. Expired compromised certificates are generally not. I think whole thing could be solved by having soft and hard expiry dates. It is an extensible format after all.

That would open a new vector of attack where an attacker would simply have to compromise any of your previous certs; not necessarily an easy feat but still a new vector

mehrdadn 6y ago

No it doesn't? All that happens is the previous cert would be accepted with a milder warning for a few weeks (not permanently) after you get a new one. It's just a small grace window to let users still be able to use the site. Just like an expiration date on your milk. There's no need to toss it out immediately just because an extra nanosecond passed.

lilyball 6y ago
This would require everyone to understand that previous certs still require high-security for at least a few weeks post expiration. This is not something we can rely on people understanding.
- im3w1l 6y ago
  Allowing bypass is the old way of doing things, and many non-browsers still allow it, so you should ideally hold on to old certs indefinitely, but at least for a short while.
- deleted 6y ago
  [deleted]
- darkerside 6y ago
  I think this is reasonable for people dealing with SSL, like expecting a mechanic to know you change an oil filter when you change the oil.
- zeroimpl 6y ago
  I'm pretty sure that most people, upon having one of their certs expire, do not find the private key and release it publicly. In fact they often generate a new cert from the same key...
- bendbro 6y ago
  Alternatively we could have people understand all certificates, regardless of expiration, are high security. Is there any reason someone would want to publicize an expired certificate? Additionally, I can think of a few existing reasons someone would avoid publicizing an expired certificate.
bawolff 6y ago
Training users that "mild" warnings can be ignored is very bad for security, as users have trouble differentiating severity. Hsts does not even give users a choice because nobody could come up with a scary enough warning.
- mehrdadn 6y ago
  I'd argue the problem might be the opposite: people are willing to differentiate on some matters (not everything), but security folks fail to help them do so. They treat every warning like DEFCON 1, as if an expired certificate is remotely similar to a compromised one. People already understand expiration dates aren't exact. They deal with it in all kinds of places. It's not a new concept.
  - bawolff 6y ago
    So what exactly do you want changed? A warning already comes up explaining what happened that a user can click through. Unless the website has opted into strict mode, in which case warnings cannot be bypassed, which seems very reasonable. > People already understand expiration dates aren't exact. They deal with it in all kinds of places. It's not a new concept. Try crossing the border with an expired passport and see how non-exact expiry dates are.
    - mehrdadn 6y ago
      > So what exactly do you want changed? A warning already comes up explaining what happened that a user can click through. Unless the website has opted into strict mode, in which case warnings cannot be bypassed, which seems very reasonable. I'm saying load the website by default; just display a warning that isn't too intrusive or alarming. As a starting point (not suggesting this is peak UX; it's just a starting point for the discussion): it could be just a small balloon notification on the padlock with black text, nothing in red or otherwise alarming (or maybe becoming more red as more time has passed). A little bit like the balloon Chrome displays for "Disable developer-mode extensions". It still lets you use the browser but also gets its point across. > Try crossing the border with an expired passport and see how non-exact expiry dates are. You couldn't think of expiration dates for things that aren't at the extreme? Maybe for actions whose gravity is a little bit more comparable to visiting a website than, say, crossing an international border?

stefan_ 6y ago

In a world where you can simply compromise a cert of your choice we can get rid of the TLS theatre altogether. No, the world we have is one where these expiry mishaps happen all the time, and everyone would be better served if certs had a warning expiration date in addition to the red alert one. It's the old "don't delete a customer the second they are late on a single payment" thing that everyone long recognizes as good practice.

bawolff 6y ago
A difference is non expired compromised certificates are usually revoked. Expired compromised certificates are generally not. I think whole thing could be solved by having soft and hard expiry dates. It is an extensible format after all.