5 ms·

From the original part: "MCS Holdings on the basis that MCS would only issue certificates for domains that they had registered" I don't understand why this wou

From the original part: "MCS Holdings on the basis that MCS would only issue certificates for domains that they had registered" I don't understand why this would be allowed. Like, doesn't this break the entire concept of a CA if the CA will allow third parties to issue certs? I understand the need for corp MITM but that's best done by pushing out your own CA. And I understand the desire for a company to have its own self-managed CA system that's publicly trusted. But that simply cannot require the CA to put any trust into the other company; there's gotta be technical measures. That's why I'm confused as to why it matters if an HSM was used or not. Can someone enlighten me on what's going on?

anfedorov 12y ago
It's just an organizational decision. CNNIC is super trustworthy to a lot of people. It's so many people, in fact, that they can't possibly verify all of the sites these people want to visit. So instead of burdening CNNIC with verifying the identity of every single site that wants a cert that their users will trust, CNNIC will just verify some other CAs as being trustworthy enough to do the job. Personally, I think I should trust the hardware or OS manufacturer to pick exactly who is trustworthy enough to certify websites, since I'm trusting them that my computer is doing what it looks like it's doing anyway.
- click170 12y ago
  I trust my OS to suggest sane defaults, but if I can't override them that's a bug IMO.
  - andreyf 12y ago
    Good point. You're still trusting them to implement the rest of the system you are using securely, though.
- est 12y ago
  > CNNIC is super trustworthy to a lot of people No, CNNIC is not even trustworthy among Chinese Internet users. CNNIC invented tons of rootkit adware and spyware. It has a very bad reputation. Google for 3721 中文网址 if you are interested Although it claims to be a neutral non-profit organization, it does have multiple for-profit business lines. In the past CNNIC belongs to China Academy of Science, but now it's just a puppet under ruling Party's control[1][2]. [1]: http://en.wikipedia.org/wiki/Central_Leading_Group_for_Internet_Security_and_Informatization http://en.wikipedia.org/wiki/Central_Leading_Group_for_Inter... [2]: News in Chinese http://tech.gmw.cn/2014-12/27/content_14311910.htm http://tech.gmw.cn/2014-12/27/content_14311910.htm
  - blacktulip 12y ago
    > No, CNNIC is not even trustworthy among Chinese Internet users. CNNIC is not trustworthy especially among Chinese Internet users.
    - crazychrome 12y ago
      absolutely! In general I trust pure commercial organisations more than govt. and non-profit orgs.
  - andreyf 12y ago
    > CNNIC is not even trustworthy among Chinese Internet users. Oh? Then why did Firefox, Google, Microsoft, Apple, etc. trust their root certificate? I know hating on China is all the rage, but something isn't making sense here... > Google for 3721 中文网址 if you are interested Just did. Got nothing. Are you referring to [1]? I'm not seeing what that has to do with CNNIC. 1. https://en.wikipedia.org/wiki/Yahoo!_Assistant https://en.wikipedia.org/wiki/Yahoo!_Assistant
    - est 12y ago
      > Oh? Then why did Firefox, Google, Microsoft, Apple, etc. trust their root certificate? Mozilla no longer trust CNNIC. https://blog.mozilla.org/security/2015/04/02/distrusting-new-cnnic-certificates/ https://blog.mozilla.org/security/2015/04/02/distrusting-new...
      - andreyf 12y ago
        Yes, hence my using the past tense. I do not see how "CNNIC is [not trustworthy]" is compatible with "Firefox, Google, Apple, and Microsoft trusted their certificates until MCS Holding screwed up some corporate network's https-interception implementation". In particular, was there any evidence of any mis-deeds by the CNNIC before what MCS Holding did? Anything at all aside from "they are a Chinese and that is bad" FUD? Have they ever issued a certificate used to MITM the communications of political dissidents, for example?
    - 12y ago
rtpg 12y ago
I think it's possible for the CA to delegate the authority to a specific subset of domains. But in this case MCS holdings apparently was given a certificate allowing them control over everything.
- finnn 12y ago
  I'm not 100% sure, but fairly certain the way that x.509 works, there is a boolean field for whether or not the certificate is an authority, with no control over what they are an authority for. I believe this field is called basic constraints.
  - briansmith 12y ago
    There is something called "name constraints" in X.509 that can be used to control which domain names, email addresses, etc. a sub-CA certificate can issue certificates for. See [1]. CAs are using them more and more frequently, especially after Mozilla added items #9 and #10 [2] to its inclusion policy a couple years ago. [1] http://tools.ietf.org/html/rfc5280#section-4.2.1.10 http://tools.ietf.org/html/rfc5280#section-4.2.1.10 [2] https://www.mozilla.org/en-US/about/governance/policies/security-group/certs/policy/inclusion/ https://www.mozilla.org/en-US/about/governance/policies/secu...
    - deathanatos 12y ago
      Are there any CAs issuing these? How do I get a CA certificate with a name constraint for my domain?
      - brohee 12y ago
        Have you reasons to believe the existing x509 certificates handling code handles properly an extension that is seldom used, and will do it in all cases? Validation of x509 certificates is ridiculously complex, and CA rightfully only use the widely interoperable subset of extensions...
        12y ago
JoshTriplett 12y ago
The missing detail is that this "delegation" to an intentionally MITMing CA should never have been made in the first place. Using such a certificate in an HSM does not make that acceptable, and I don't have the impression that it would have been acceptable even in an HSM; I think that portion of the article was simply relaying the information CNNIC provided (in which they're trying to shift the blame onto MCS Holdings for further mishandling of an intermediate CA that should never have been issued in the first place). The claim from CNNIC was that the intermediate CA would only be used for domains actually managed by MCS Holdings; however, there's no technical control in place to ensure that, even if you believe CNNIC didn't know exactly what the intermediate CA would be used for.
- geofft 12y ago
  There was no intention to MITM here. MCS's goal was to become a certificate authority, and it's common practice for a new CA to get their CA cert signed by an existing one. Let's Encrypt is planning on doing exactly this, for instance. What went horribly wrong is that nobody knew what they were doing, CNNIC didn't realize they had an obligation to bring in auditors to both CNNIC and MCS to make sure that people knew what they were doing, and MCS unintentionally placed the cert on a device that happens to do real-time SSL MITM. I believe CNNIC's claim is about the "test" certificate that was issued to MCS. (The fact that they issued a test certificate off of a publicly-trusted one is another sign they didn't know what they were doing.) There's a long thread on mozilla.dev.security.policy with replies by CNNIC and MCS that explains the story. (The CNNIC rep's English is pretty good, MCS's is good enough to get a sense of things.) https://groups.google.com/forum/#!topic/mozilla.dev.security.policy/czwlDNbwHXM https://groups.google.com/forum/#!topic/mozilla.dev.security...
  - JoshTriplett 12y ago
    > MCS unintentionally placed the cert on a device that happens to do real-time SSL MITM That's right up there with "unintentionally loaded a gun, drove to the bank, held it up at gunpoint, and left with bags full of cash", and about as believable. If it really was unintentional, then it's still a level of incompetence sufficiently indistinguishable from malice that it should be treated as malice. Maintaining certificate security is the primary job of a certificate authority. A certificiate authority that utterly failing to do so should be removed from the trusted CA list, as has occurred here.

anfedorov 12y ago

It's just an organizational decision. CNNIC is super trustworthy to a lot of people. It's so many people, in fact, that they can't possibly verify all of the sites these people want to visit. So instead of burdening CNNIC with verifying the identity of every single site that wants a cert that their users will trust, CNNIC will just verify some other CAs as being trustworthy enough to do the job. Personally, I think I should trust the hardware or OS manufacturer to pick exactly who is trustworthy enough to certify websites, since I'm trusting them that my computer is doing what it looks like it's doing anyway.

click170 12y ago
I trust my OS to suggest sane defaults, but if I can't override them that's a bug IMO.
- andreyf 12y ago
  Good point. You're still trusting them to implement the rest of the system you are using securely, though.
est 12y ago
> CNNIC is super trustworthy to a lot of people No, CNNIC is not even trustworthy among Chinese Internet users. CNNIC invented tons of rootkit adware and spyware. It has a very bad reputation. Google for 3721 中文网址 if you are interested Although it claims to be a neutral non-profit organization, it does have multiple for-profit business lines. In the past CNNIC belongs to China Academy of Science, but now it's just a puppet under ruling Party's control[1][2]. [1]: http://en.wikipedia.org/wiki/Central_Leading_Group_for_Internet_Security_and_Informatization http://en.wikipedia.org/wiki/Central_Leading_Group_for_Inter... [2]: News in Chinese http://tech.gmw.cn/2014-12/27/content_14311910.htm http://tech.gmw.cn/2014-12/27/content_14311910.htm
- blacktulip 12y ago
  > No, CNNIC is not even trustworthy among Chinese Internet users. CNNIC is not trustworthy especially among Chinese Internet users.
  - crazychrome 12y ago
    absolutely! In general I trust pure commercial organisations more than govt. and non-profit orgs.
- andreyf 12y ago
  > CNNIC is not even trustworthy among Chinese Internet users. Oh? Then why did Firefox, Google, Microsoft, Apple, etc. trust their root certificate? I know hating on China is all the rage, but something isn't making sense here... > Google for 3721 中文网址 if you are interested Just did. Got nothing. Are you referring to [1]? I'm not seeing what that has to do with CNNIC. 1. https://en.wikipedia.org/wiki/Yahoo!_Assistant https://en.wikipedia.org/wiki/Yahoo!_Assistant
  - est 12y ago
    > Oh? Then why did Firefox, Google, Microsoft, Apple, etc. trust their root certificate? Mozilla no longer trust CNNIC. https://blog.mozilla.org/security/2015/04/02/distrusting-new-cnnic-certificates/ https://blog.mozilla.org/security/2015/04/02/distrusting-new...
    - andreyf 12y ago
      Yes, hence my using the past tense. I do not see how "CNNIC is [not trustworthy]" is compatible with "Firefox, Google, Apple, and Microsoft trusted their certificates until MCS Holding screwed up some corporate network's https-interception implementation". In particular, was there any evidence of any mis-deeds by the CNNIC before what MCS Holding did? Anything at all aside from "they are a Chinese and that is bad" FUD? Have they ever issued a certificate used to MITM the communications of political dissidents, for example?
  - 12y ago

rtpg 12y ago

I think it's possible for the CA to delegate the authority to a specific subset of domains. But in this case MCS holdings apparently was given a certificate allowing them control over everything.

finnn 12y ago
I'm not 100% sure, but fairly certain the way that x.509 works, there is a boolean field for whether or not the certificate is an authority, with no control over what they are an authority for. I believe this field is called basic constraints.
- briansmith 12y ago
  There is something called "name constraints" in X.509 that can be used to control which domain names, email addresses, etc. a sub-CA certificate can issue certificates for. See [1]. CAs are using them more and more frequently, especially after Mozilla added items #9 and #10 [2] to its inclusion policy a couple years ago. [1] http://tools.ietf.org/html/rfc5280#section-4.2.1.10 http://tools.ietf.org/html/rfc5280#section-4.2.1.10 [2] https://www.mozilla.org/en-US/about/governance/policies/security-group/certs/policy/inclusion/ https://www.mozilla.org/en-US/about/governance/policies/secu...
  - deathanatos 12y ago
    Are there any CAs issuing these? How do I get a CA certificate with a name constraint for my domain?
    - brohee 12y ago
      Have you reasons to believe the existing x509 certificates handling code handles properly an extension that is seldom used, and will do it in all cases? Validation of x509 certificates is ridiculously complex, and CA rightfully only use the widely interoperable subset of extensions...
      - 12y ago

JoshTriplett 12y ago

The missing detail is that this "delegation" to an intentionally MITMing CA should never have been made in the first place. Using such a certificate in an HSM does not make that acceptable, and I don't have the impression that it would have been acceptable even in an HSM; I think that portion of the article was simply relaying the information CNNIC provided (in which they're trying to shift the blame onto MCS Holdings for further mishandling of an intermediate CA that should never have been issued in the first place). The claim from CNNIC was that the intermediate CA would only be used for domains actually managed by MCS Holdings; however, there's no technical control in place to ensure that, even if you believe CNNIC didn't know exactly what the intermediate CA would be used for.

geofft 12y ago
There was no intention to MITM here. MCS's goal was to become a certificate authority, and it's common practice for a new CA to get their CA cert signed by an existing one. Let's Encrypt is planning on doing exactly this, for instance. What went horribly wrong is that nobody knew what they were doing, CNNIC didn't realize they had an obligation to bring in auditors to both CNNIC and MCS to make sure that people knew what they were doing, and MCS unintentionally placed the cert on a device that happens to do real-time SSL MITM. I believe CNNIC's claim is about the "test" certificate that was issued to MCS. (The fact that they issued a test certificate off of a publicly-trusted one is another sign they didn't know what they were doing.) There's a long thread on mozilla.dev.security.policy with replies by CNNIC and MCS that explains the story. (The CNNIC rep's English is pretty good, MCS's is good enough to get a sense of things.) https://groups.google.com/forum/#!topic/mozilla.dev.security.policy/czwlDNbwHXM https://groups.google.com/forum/#!topic/mozilla.dev.security...
- JoshTriplett 12y ago
  > MCS unintentionally placed the cert on a device that happens to do real-time SSL MITM That's right up there with "unintentionally loaded a gun, drove to the bank, held it up at gunpoint, and left with bags full of cash", and about as believable. If it really was unintentional, then it's still a level of incompetence sufficiently indistinguishable from malice that it should be treated as malice. Maintaining certificate security is the primary job of a certificate authority. A certificiate authority that utterly failing to do so should be removed from the trusted CA list, as has occurred here.