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Will that “non-profit” be ok with my site raving about Russia’s involvment in Ukraine? What about a fan website for the Iranian Ayatollah? Or a website describi

Will that “non-profit” be ok with my site raving about Russia’s involvment in Ukraine? What about a fan website for the Iranian Ayatollah? Or a website describing in detail Taiwan’s vulnerable targets just as China is about to attack them? Chances are that the answer to all those questions is “no, the Western-run Let’s Encrypt will not be ok with all that” and if it were for the push to come to the shove (or whatever the expression is) they’ll be more than glad to invalidate that certificate (or worse, to compromise it without letting you know). Granted, the same thing will most probably happen with one’s DNS provider and with his/her ISP, but why have another dependency if one can avoid it?

sholladay 3y ago
Let’s Encrypt was created in part to take humans out of the loop where possible. LE does not review your site and that is made obvious by the speed of getting a certificate and the automated renewals, etc. They aren’t aware of you unless there’s a technical error or you’ve made headline news. That said, I agree with you that there is some level of risk here, even if it is small. That’s why your ability to switch is so important. Even if they became aware of you and they decided to revoke your certificate, you would just switch providers. Because of that, they have no meaningful power over you. If it ever becomes difficult to switch, then things are getting bad. > or worse, to compromise it without letting you know What does that mean? The certificate either passes validation or it doesn’t. They aren’t able to change the content on your site or anything like that.
- paganel 3y ago
  >What does that mean? The certificate either passes validation or it doesn’t. They aren’t able to change the content on your site or anything like that. They could say that your certificate passes validation while, in fact, said security has been already tampered with on your side, giving your website's visitors a sense of false security.
  - woodruffw 3y ago
    > They could say that your certificate passes validation while, in fact, said security has been already tampered with on your side, giving your website's visitors a sense of false security. This isn't how the Web PKI works. In order to tamper with your site's traffic, Let's Encrypt (or another CA) would need to issue another certificate for your site with a key that they (rather than you) control. This would be detected via CT[1], which your browser (unless it's Firefox) is already using. And note: by design, any CA in the trusted set can already do this, regardless of whether you use them or not. The things that are stopping them are that it's (1) not in their interest to do so, (2) it's detectable due to CT, and (3) would result in their root being hell-banned by the browsers. [1]: https://certificate.transparency.dev/ https://certificate.transparency.dev/
    - paganel 3y ago
      I was thinking of actions taken by state actors in the context of the current geo-political climate. As such (1) can be easily brushed-off if a national security letter from a 3-letter agency is in the mailbox, (2) is debatable, but looking at that "transparency list" I mostly see Western companies, companies which I suppose are also subject to that kind of correspondence, as for (3), afaik two of the biggest browsers now on the market are controlled by companies actively working with the US defence apparatus, including Google [1]. [1] https://www.nytimes.com/2021/11/15/technology/google-ai-pentagon.html https://www.nytimes.com/2021/11/15/technology/google-ai-pent...
      - woodruffw 3y ago
        Again: this has nothing to do with LE; any CA can issue any certificate at any time by design, and it's the responsibility of the CT scheme to detect misissuances and malevolent behavior. A NSL sent to the operators of a CT log cannot stop the log operators from logging inauthentic certificates: each CT log is a timely and append-only signed ledger of all certificates issued, meaning that any deviation between logs would also be detected and treated as a sign of mis-issuance or compromise by the larger Web PKI. What's more, certificates need to be logged as a matter of validity: an order compelling log operators to refuse a certificate would effectively ensure that the certificate never becomes valid. That's what makes CT nice: anybody who wants to create a malicious certificate needs to do so in a way that's globally detectable. It can be fun to play mind games about shadowy agencies, but that's not really how these things work: if you're of sufficient interest to a country's intelligence service, then they're going to spearphish you, exploit your phone, steal your TLS session keys, your cookies, or do any number of other much less visible things to get the access they want. And, if they're competent, they will get it[1]. [1]: https://www.usenix.org/system/files/1401_08-12_mickens.pdf https://www.usenix.org/system/files/1401_08-12_mickens.pdf
jrockway 3y ago
Has Let's Encrypt ever shut down someone's ability to get a certificate over independent editorial concerns?
- lmm 3y ago
  IIRC they either outright refused to provide a certificate to KiwiFarms, or have close enough ties to ISPs who cut them off that applying seemed like a non-starter.
  - SahAssar 3y ago
    Do you have a source? Some quick searching only brought up cloudflare dropping them.
    - lmm 3y ago
      Not to hand, and if I did it would probably be a post on the forum itself, which, well, you see the problem.
      - woodruffw 3y ago
        I would go ahead and hazard that “major DV CA refuses to validate controversial site” would be major news. There’s no evidence that LE has ever done this, much less ever considered it, much less even has the basic technical ability to manually intervene in the DV process.
        lmm 3y ago
        Hardcoding a check for whether the domain is a particular fixed string is trivial. Any competent technical organisation can do that in less than a day. Yes it wouldn't be principled or elegant, but it would work. Currently LE looks like neutral infrastructure that would never do such a thing. But so did CloudFlare, right up until the point where they suddenly weren't.

sholladay 3y ago

Let’s Encrypt was created in part to take humans out of the loop where possible. LE does not review your site and that is made obvious by the speed of getting a certificate and the automated renewals, etc. They aren’t aware of you unless there’s a technical error or you’ve made headline news. That said, I agree with you that there is some level of risk here, even if it is small. That’s why your ability to switch is so important. Even if they became aware of you and they decided to revoke your certificate, you would just switch providers. Because of that, they have no meaningful power over you. If it ever becomes difficult to switch, then things are getting bad. > or worse, to compromise it without letting you know What does that mean? The certificate either passes validation or it doesn’t. They aren’t able to change the content on your site or anything like that.

paganel 3y ago
>What does that mean? The certificate either passes validation or it doesn’t. They aren’t able to change the content on your site or anything like that. They could say that your certificate passes validation while, in fact, said security has been already tampered with on your side, giving your website's visitors a sense of false security.
- woodruffw 3y ago
  > They could say that your certificate passes validation while, in fact, said security has been already tampered with on your side, giving your website's visitors a sense of false security. This isn't how the Web PKI works. In order to tamper with your site's traffic, Let's Encrypt (or another CA) would need to issue another certificate for your site with a key that they (rather than you) control. This would be detected via CT[1], which your browser (unless it's Firefox) is already using. And note: by design, any CA in the trusted set can already do this, regardless of whether you use them or not. The things that are stopping them are that it's (1) not in their interest to do so, (2) it's detectable due to CT, and (3) would result in their root being hell-banned by the browsers. [1]: https://certificate.transparency.dev/ https://certificate.transparency.dev/
  - paganel 3y ago
    I was thinking of actions taken by state actors in the context of the current geo-political climate. As such (1) can be easily brushed-off if a national security letter from a 3-letter agency is in the mailbox, (2) is debatable, but looking at that "transparency list" I mostly see Western companies, companies which I suppose are also subject to that kind of correspondence, as for (3), afaik two of the biggest browsers now on the market are controlled by companies actively working with the US defence apparatus, including Google [1]. [1] https://www.nytimes.com/2021/11/15/technology/google-ai-pentagon.html https://www.nytimes.com/2021/11/15/technology/google-ai-pent...
    - woodruffw 3y ago
      Again: this has nothing to do with LE; any CA can issue any certificate at any time by design, and it's the responsibility of the CT scheme to detect misissuances and malevolent behavior. A NSL sent to the operators of a CT log cannot stop the log operators from logging inauthentic certificates: each CT log is a timely and append-only signed ledger of all certificates issued, meaning that any deviation between logs would also be detected and treated as a sign of mis-issuance or compromise by the larger Web PKI. What's more, certificates need to be logged as a matter of validity: an order compelling log operators to refuse a certificate would effectively ensure that the certificate never becomes valid. That's what makes CT nice: anybody who wants to create a malicious certificate needs to do so in a way that's globally detectable. It can be fun to play mind games about shadowy agencies, but that's not really how these things work: if you're of sufficient interest to a country's intelligence service, then they're going to spearphish you, exploit your phone, steal your TLS session keys, your cookies, or do any number of other much less visible things to get the access they want. And, if they're competent, they will get it[1]. [1]: https://www.usenix.org/system/files/1401_08-12_mickens.pdf https://www.usenix.org/system/files/1401_08-12_mickens.pdf

jrockway 3y ago

Has Let's Encrypt ever shut down someone's ability to get a certificate over independent editorial concerns?

lmm 3y ago
IIRC they either outright refused to provide a certificate to KiwiFarms, or have close enough ties to ISPs who cut them off that applying seemed like a non-starter.
- SahAssar 3y ago
  Do you have a source? Some quick searching only brought up cloudflare dropping them.
  - lmm 3y ago
    Not to hand, and if I did it would probably be a post on the forum itself, which, well, you see the problem.
    - woodruffw 3y ago
      I would go ahead and hazard that “major DV CA refuses to validate controversial site” would be major news. There’s no evidence that LE has ever done this, much less ever considered it, much less even has the basic technical ability to manually intervene in the DV process.
      - lmm 3y ago
        Hardcoding a check for whether the domain is a particular fixed string is trivial. Any competent technical organisation can do that in less than a day. Yes it wouldn't be principled or elegant, but it would work. Currently LE looks like neutral infrastructure that would never do such a thing. But so did CloudFlare, right up until the point where they suddenly weren't.