Thanks Peter for the questions. The answers are listed below: First, a couple of questions about DigiCert itself. The press release at https://thomabravo.com/2015/10/22/thoma-bravo-completes-acquisition-of-majority-stake-in-digicert/ says that Thoma Bravo acquired a majority stake in DigiCert in October 2015. Looking at the current portfolio (https://thomabravo.com/portfolio/all/current/), I don't see any other CAs, but can you confirm that (a) they still own a majority & controlling share of DigiCert and (b) that Thoma Bravo does not own a majority or controlling share (directly or indirectly) of any other CA?
[JR] Yes - Thoma Bravo owns a controlling interest in DigiCert. However, I can't say exactly which companies are owned by Thoma Bravo. That information isn't shared with us other than as disclosed publicly on their website. I do not think they own another CA though. What is the relationship between Cyber Secure Asia (https://www.cybersecureasia.com/about-cyber-secure-asia-csa/newsroom) and DigiCert? Are they a subsidiary, a subordinate CA, a reseller or something else? It is hard to tell, as they talk about DigiCert all over their site but also say something about being a subsidiary of CyberTrust Japan (which might be part of DigiCert?) [JR] They are a reseller. They don't control an issuing CA. > About a year ago in > July, DigiCert closed an agreement with Verizon where DigiCert took > ownership of three publicly-trusted Verizon root certificates. These > certificates are the Verizon Global Root CA, the Baltimore CyberTrust > Root CA, and the Verizon Root CA. According to https://mozillacaprogram.secure.force.com/CA/IncludedCACertificateReport, DigiCert currently has 10 roots in the Mozilla trust anchor list. These include eight with "DigiCert Inc" in the organization name attribute, one with "Baltimore" in the organization name attribute, and one with "CyberTrust, Inc" in the organization name attribute. The removed CA report (https://mozillacaprogram.secure.force.com/CA/RemovedCACertificateReport) lists one root as belonging to DigiCert. This has "GTE Corporation" in the organization name attribute. [JR] We acquired this root with the transaction. The root is not publicly trusted and was removed from the root store prior to the acquisition. You list three root certificates in your email. Which of the DigiCert certificates in the Mozilla root reports map to the three you list? [JR] All DigiCert roots and all issuing CAs chained to the DIgiCert root are owned and operated by DIgiCert. The DigiCert roots have never cross-signed another CA. There is a one-way trust between the Verizon roots and DigiCert where Verizon cross-signed for ubiquity. All of them have the potential to chain back to Verizon, but we usually turn this off by default. You talk about taking ownership of three "root certificates". Did you also take ownership and control of all copies of the associated private keys? Did you take control of other CAs and private keys (e.g. subordinate CAs) or just the three listed above? [JR] Over the last year, we took physical possession of the private keys of two roots. This possession was limited to the root certificates and did not include issuing CAs chained to the roots. The final root (the Cybertrust Global root) should be transferred into our infrastructure this month. Contractually, we needed to keep the root in Europe for a while after the acquisition. > After watching the > issuance of wildcard EV certs, non-compliant subordinate CAs, and > certs with poor profiles, we made a conscious decision to purchase > these roots with the intention of migrating them to more complaint > system. We felt that helping these CAs get to the point of regular > audits and best practices would raise the quality of the entire industry. So would just revoking them. [JR] True, but we weren't aware of any browser plans to revoke the Verizon root certificates. Nothing was publicly announced, and we felt that the Baltimore root was essential in the ecosystem because of the companies it supports. We thought moving the roots into DigiCert resolve previous concerns about the issuance processes and lack of profile control without the browsers needing to take a drastic measure that would distrust several prominent certificate authorities. > Unfortunately, the age of the > roots and large number of cross-signs led to a lot of missing > paperwork and certain issues in identifying which CAs were covered by > audits. Prior to closing we believed there were approximately five > technically constrained sub CAs and around 20 unconstrained sub CAs. > Turns out there were actually more than 200, each with various levels > of compliance. Most of these Sub CAs operated under the Baltimore Cybertrust > root, which was created in 2000. > To their credit, Verizon revoked 48 of the issuing CAs prior to > DigiCert's acquisition of the roots. Given this huge variance, how sure are you that you have identified all the CA certificates issued by these roots? Did all of the CA certificates include zero path length constraints or are there possibly whole trees of CAs out there that are unknown? [JR] Although we have done everything we can to find these CAs, I'm not honestly sure how anyone would ever know if all the issuing CA certificates were accurately identified. We've looked through issuing records and are monitoring the CT logs, crt.sh, censys.io, as well as our own web crawler to see if any turn up. Our and Google's CT logs are how we originally identified may of the 200 issuing CAs. > After our operational acquisition of the roots (which occurred the > last part of September, 2015), we identified 15 expired issuing CAs, > 70 revoked sub CAs, 131 audited sub CAs, and 36 where the status was > unknown. Since then, we've revoked 25 issuing CAs and assisted others > with technical constraints, exodus from the Omniroot cross-signing program, > or obtaining audits. What is "Omniroot"? [JR] The brand name assigned by Verizon to their external cross-signing program. How many of these are operated by DigiCert and how many are operated by unaffiliated third parties? Kathleen added a field I requested to the required disclosures of "Management Assertions By", but I think the intent got lost. I meant it to be the legal entity that operates that CA, so the answer to this question would be clear, but most are filled by the name of the individual signing the assertion, which isn't all that useful. [JR] The number operated by unaffiliated third parties is quickly diminishing as CAs transfer into a hosted solution or to another provided. I think the field is unclear on what was supposed to be logged. The CAs covered by DigiCert's audit are hosted by DigiCert. Everything else is external, although several of them are hosted by Verizon. > The seven companies listed below are responsible for the remaining > unaudited sub CAs: To be clear, when you say "responsible", do you mean they hold the private key and control decisions on what certificates get issued by the CA? [JR] Yes. They are external sub CAs where the keys and validation is controlled by the company named in the certificate. The easiest way to identify which issuing CAs are controlled by DigiCert and which are external is with the Mozilla Salesforce list. Any CAs we operate are covered by our audit. > 1. ABB has three unaudited issuing CAs. ABB didn't undergo an audit > earlier this year on the assumption that their sub CAs were > technically constrained. Unfortunately, the constraints weren't > properly implemented, a fact that escaped notice until Rob Stradling's > excellent tool exposed a deficiency a few months ago in how Verizon > issuance process. Although Verizon restricted domain names and IPv4 IP > addresses, the CAs could still issue for the IPv6 space. Despite > promptly replacing the certificates after discovering the gap, we > haven't revoked the issuing CAs. Right now, ABB is actively working to > transition its servers to the new, properly-constrained certificates. > We expect the transition to complete by the end of December 2016. We > are revoking the issuing CAs as the migration completes and expect all > of the ABB non-compliant issuing CAs to be revoked on January 5th. No new > certs are being issued from the faulty issuing CAs. When you say you "replaced the certificates" it is not clear what this means. Do the partially-constrained and the new technically constrained CA certificates have the same subject distinguished name, subject public key info, and/or subject key identifiers or are all three different? [JR] Different keys but same subject info. We've essentially created new issuing CAs and are revoking the ones created by Verizon. > 2. Similar to ABB, Verizon created two technically constrained issuing > CAs for Bechtel. Like ABB, Verizon failed to restrict IPv6 issuance > for each of the issuing CAs. Bechtel is actively migrating the > remaining 785 certificates to properly constrained issuing CAs. The > migration process will complete at the end of December, after which > the non-conforming issuing CAs will be revoked. They are included in > our January 5th revocation plan. This will also revoke the three issuing CAs > created further down in the chain. Same question as for ABB. [JR] Same answer. > 3. Dell also thought they were technically constrained. Similar to ABB > and Bechtel, the restriction was inadequate. Fortunately, Dell isn't > using the issuing CAs and doesn't require migration. We've previously > revoked four issuing certificates (Bug 1279066) but missed one during > the process. We plan to immediately revoke the remaining issuing CA > and all CAs subordinate to the issuing CA. This seems very straight forward. No questions. > 4. While Certipost is hosted by Verizon's internal infrastructure, the > Verizon WebTrust audit letter did not specifically identify the > Certipost CAs as audited. DigiCert has been in the process of revoking > these CAs but there is some confusion about the effects of the > revocation. Apparently the certificates are used for air traffic > control in Europe and there is a fear that revoking the intermediate may > cause planes to fall out of the sky. > After trying to sort out this mess and giving Certipost time to > transition, we've decided to revoke the issuing certificates the last week of > November. > We believe there are over 400 outstanding certificates that will be > affected. When you say "Verizon's internal infrastructure", does this mean DigiCert now hosts this or did Verizon retain some CA infrastructure? Either way, what control does Certipost have over the CA private key? Assuming Verizon still controls the key, why is it not in their audit reports? [JR] Verizon still has a CA infrastructure that hosts issuing CAs for their customers that refused to migrate or are still migrating to DigiCert or another CA. The infrastructure also hosts keys and certs Verizon uses internally for certificates. We took control of the root certificates and have spent the last year transitioning CAs to DigiCert's hosted CA solution or bringing them into compliance with the BRs and root program policies. The certificates hosted by Verizon are being revoked as the migrations complete. All issuing CAs hosted by Verizon are theoretically covered by the Verizon audits. However, Verizon's auditors still use the "old school" style audit reports where only the roots are listed. Verizon has had another audit, and we've asked that the new audit report list each issuing CA individually so we can better identify which are hosted by Verizon and which are operated externally. > 5. Postecom refused an audit and decided to exit operation of a CA. We > have not yet revoked their issuing CAs in order to give them time to > migrate to a different CA infrastructure. They asked that we keep the > issuing CAs active until December 31, 2016 to complete the migration. > Although they have worked on migrating certs, Postecom still has 1185 > certificates to migrate in the next two months. The issuing CAs are > scheduled for revocation on January 5th. When you say "keep the issuing CAs active", does this mean they are still signing certificates using these CA private keys or are they in a CRL/OCSP-only mode? [JR] Supposedly in CRL/OCSP mode, but we know they have issued a few certificates this year. Of course, all certs will cease functioning on Jan 5th when we revoke the issuing CA. > 6. Vodafone completed a Webtrust audit this year. Unfortunately, we > found out that the audit has qualifications. The audit report hasn't > issued yet but should later in November. Has Vodafone ever previously had a WebTrust audit (using any of the criteria sets)? [JR] We don't know. The documentation is very bad.. I'm not even sure Vodafone was told they needed an audit until we took over. The requirements caught them by surprise. > Once the audit report issues, we will > provide a copy of the report for evaluation. We've been told that the > qualifications are related to the network security guidelines. They > probably also include the SHA1 issuance, although we haven't been told that > directly. As discussed at the CA/Browser Forum meeting a few weeks ago, they would not be unique in ending up with a qualified audit due to the network security guidelines. However the scope of non-compliance could be much greater than that of other non-compliant CAs. [JR] Agreed. We are awaiting the audit report to evaluate. We don't know the exact qualifications yet and plan to adjust the plan based on what is revealed in the report. > Vodafone is currently designing and building a new CA infrastructure > that will house all of their operations. To ensure compliance, we are > requiring the new infrastructure to undergo a point-in-time audit in > December. We are also requiring a full audit on their issuance > processes at the start of next year. A full, non-qualified audit report is > expected by March 31, 2016. This seems a little aggressive. The minimum period for a WebTrust period of time report is 60 days; assuming they start operation on December 1, the earliest end of period would be January 31, but I suspect it will be later than that. I would suggest that they follow the rules as if they were a brand new CA and get a period of time audit that has a period of at least 60 days and ends within 90 days of issuing their first public certificate. They then have 90 days to publish the report. [JR] Yes. We wanted a very aggressive plan as Vodafone is currently out of compliance. However, we're happy to give them more leeway if everyone agrees. Vodafone has been very responsive and easy to work with. Unfortunately, Vodafone received little to no information about the CAB Forum requirements prior to the acquisition and were caught by surprise when we told them they needed a BR and network security guideline audit. I think they had a standard audit prior to that, but there isn't enough documentation to tell. Vodafone also recently overhauled their CA staff and infrastructure, which has delayed compliance slightly. > Although this is well past the compliance date, we are sympathetic to > Vodafone as they have been actively working towards compliance. They > also have 4,580 public facing SSL certs makes revocation tricky. They > issue a lot of client certificates from these sub CAs where revocation > could have a potentially devastating effect on telecommunications. > Because of the large impact of revocation and how hard Vodafone is > working to migrate, we'd like permission for them to comply by March > 31, 2017, assuming serious issues are not uncovered by the audit > report and that the December and January audits pass unqualified. Given that the point in time audit and subsequent audit are for "new CA infrastructure", isn't clear how this helps their current CAs. Are they still signing new certificates with their current infrastructure? [JR] Yes, Vodafone is still issuing certificates. They plan to transfer the entire operations over to the new infrastructure later this year. Although the point in time audit is for new CAs, we thought the audit would be appropriate because 1) this is a new infrastructure and, although existing certificates are included, the operations are essentially a new CA with a new team 2) the audit will show Vodafone's progress towards compliance, and 3) the audit will identify Vodafone's progress in remediating any qualifications in their existing audit. We do feel Vodafone deserves some lee-way considering they were unaware of the requirements until after the acquisition. > 7. The Belgium government is our biggest challenge [...] > Verizon has represented that the issuing CAs are hosted in the Verizon > infrastructure and are potentially covered by the Verizon audit. We've > asked Verizon to provide an updated audit report showing coverage of > the Belgium issuing CAs by December 1, 2016. If the report is not > delivered by December 1, 2016, we plan to immediately revoke the > issuing CAs. If, for whatever reason, we are unable to revoke the > issuing CAs at that time, we would certainly not object to the > browsers distrusting the issuing CAs issued to Belgium. When you say "Verizon infrastructure", does this mean DigiCert now hosts this or did Verizon retain some CA infrastructure? Either way, what control does the Belgium goverment have over the CA private keys? [JR] Verizon retains their own infrastructure that hosts the Verizon issuing CAs. DigiCert took over the roots in an audited and documented process. We don't know if Belgium controls their issuing CA's private keys or if the keys are hosted in Verizon's infrastructure. We've been told that Verizon has these keys but have yet to receive evidence of this arrangement. The continued confusion about where the issuing CAs are hosted is why we want to revoke the Belgium root on December 1, 2016 if a full audit covering the issuing CAs isn't provided. > The final CA is Nets Norway. Unlike the other two issuing CAs, Nets > Norway issued a SHA1 certificate earlier this year. Although Nets > Norway promptly revoked the certificate and provided verbal assurances > that SHA1 issuance would be restricted, the company obviously failed to take > adequate measures. > We informed Nets Norway that we are revoking their issuing CA later > this month. We haven't revoked them yet because we wanted to complete > the incident report first and allow public comment before finalizing > the decision. This seems like a reasonable plan for Nets Norway. [JR] Thanks. We're thinking the last week of November to give them time to migrate. If any additional non-compliances are discovered, we plan to revoke immediately. > Our investigation of Verizon's, Postecom's, and Telecom Italia's > issuance of a SHA1 certificate is ongoing. As mentioned above, > Postecom is scheduled for revocation. Our plan for now is to keep the > current revocation schedule for Postecom as the SHA1 issuance occurred > twice during January. We haven't formed a plan for Verizon or Telecom > Italia yet and are waiting to hear back from their representatives. > Verizon issued a single certificate back in January. Telecom Italia > issued three in early January and February. Each of these incidents > were only recently discovered by DigCert. We've since added an active > monitor to crt.sh to alert our compliance team if a SHA1 certificate issues. Has DigiCert considered requiring CT logging for subordinate CAs, either to public logs or logs readable only by DigiCert in order to help assure compliance? [JR] Yes. That is being discussed right now. We are trying to figure out the best way to do that. Some of these customers are using CA software which does not currently support CT logging and would need to have a solution for this in the near term. > Despite the difficulties in bringing these customers into compliance, > we still think the Verizon transaction was a good move from a > compliance perspective. Helping these sub CAs identify problems and > improve their processes has been an enlightening experience and given > us insight on some of the difficulties other CAs may face in complying with > the BRs. Please share any feedback on how the BRs can be improved and also any thing learned that might be relevant to other policy discussions (such as CT mandates). [JR] Thanks Peter. We really like the BRs and network security guidelines, even more so after this exercise. Certificates are not the primary business for most of these sub CAs. As such, the companies don't closely follow the risks and industry discussions. The BRs and network security guidelines give us a good standard that CAs can use as a measuring stick for compliance. We also like the public disclosures CT requires as its been essential in identifying issuing CAs and non-compliances. That's probably not a surprise as we've always strongly supported CT. I do see the need for name redaction though as lots of the certificates are issued to individuals, and the European government freaks out whenever there is the potential disclosure of PII. Sincerely, Jeremy _______________________________________________ dev-security-policy mailing list dev-security-policy@lists.mozilla.org https://lists.mozilla.org/listinfo/dev-security-policy
