> Should a self-signed certificate registered as a Root CA in CCADB have its > audit scope determined by the trust bit, rather than being required to meet > the Intermediate CA requirements?
In my view this comment<https://www.mail-archive.com/[email protected]/msg00293.html> from Ryan Sleevi is relevant to this discussion. The comment addresses a slightly different scenario, but I interpret it as supporting the crt.sh logic that is flagging the TWCA CYBER Root CA (self-signed certificate) in https://crt.sh/mozilla-disclosures#disclosureincomplete. ________________________________ From: Chya-Hung Tsai <[email protected]> Sent: 07 March 2025 03:07 To: CCADB Public <[email protected]> Cc: Rob Stradling <[email protected]>; Ben Wilson <[email protected]>; Chya-Hung Tsai <[email protected]> Subject: Re: Missing or Inconsistent Disclosure of S/MIME BR Audits This Message Is From an Untrusted Sender You have not previously corresponded with this sender. Report Suspicious<https://us-phishalarm-ewt.proofpoint.com/EWT/v1/J5K_pWsD!CWYXECd0fYqSgVOq2XhdQ-9i-55jghkuB-DnQc-iQyvLGMFQKTfG2Vw3uTHxSXeAz4mjZ5MmwTwDx8QH1tt1qlJ_-lsx2dc$> Hi Rob, We agree that the TWCA CYBER Root (self-signed certificate) meets the definition of "directly or transitively chain" as described in MRSP 5.3. However, we believe that according to MRSP 1.1, Root CAs and Intermediate CAs should be defined separately, while MRSP 5.3 specifically applies to Intermediate CAs. For example, MRSP 5.3 requires that Intermediate CAs must include an EKU, which is impossible for a Root CA to satisfy, as Root CAs do not contain an EKU field. Similarly, both the BRs and the CCADB Policy define Root CAs and Intermediate CAs separately, with different profile requirements for each. For instance, our TWCA CYBER Root has an Intermediate CA that chains up to TWCA Global Root, but we do not include it in our S/MIME audit report, as it contains an EKU field but does not include emailProtection. Since Root CAs cannot contain an EKU field, we believe that the trust bit should determine whether a CA is included in the audit scope (including both currently trusted CAs and those under application for inclusion). Including TWCA CYBER Root (self-signed certificate) in the S/MIME audit report would be highly inappropriate, as it is already designated as a single-purpose TLS hierarchy. If a Root CA is considered a subordinate CA of a cross-certificate, then that Root CA would no longer be a single-purpose TLS hierarchy. We request clarification from Mozilla or CCADB on the following matter: Should a self-signed certificate registered as a Root CA in CCADB have its audit scope determined by the trust bit, rather than being required to meet the Intermediate CA requirements? Best regards, ChyaHung Tsai TWCA Rob Stradling 在 2025年3月6日 星期四晚上11:16:41 [UTC+8] 的信中寫道： Hi ChyaHung Tsai. Firstly, I'd like to commend TWCA for its prompt attention to this matter and for seeking to understand what needs to be addressed. > Maybe our Cross‑Certified Subordinate CA Certificate (TWCA Global Root to > TWCA CYBER Root) does not include an EKU, which causes the program to also > identify TWCA CYBER Root as having the capability to issue S/MIME (inheriting > the capabilities of TWCA Global Root)? Yes, that's correct. > Additionally, our S/MIME audit report includes this Cross‑Certified > Subordinate CA Certificate, but does not include the self‑signed TWCA CYBER > Root, because that TWCA CYBER Root does not have the mail trust bit, and > therefore the "Audits Same as Parent" flag does not apply. MRSP 5.3 says "All certificates that are capable of being used to issue new certificates and that directly or transitively chain to a CA certificate included in Mozilla’s root store MUST be operated in accordance with this policy." The self-signed TWCA CYBER Root certificate "chain[s] to a CA certificate included in Mozilla's root store" that has the Email trust bit enabled, and so it "MUST be operated in accordance with" the S/MIME provisions of the MRSP. It's a suboptimal chain, but it is nonetheless a valid chain: TWCA Global Root -> TWCA CYBER Root (cross-certificate) -> TWCA CYBER Root (self-signed certificate) -> Intermediate CA Certificate -> Leaf Certificate > 6. We have noticed warnings regarding CRL expiration, but after verifying the > CRLs downloaded from the CDP, they all appear to be valid. Could you confirm? You're correct that unexpired CRLs are being returned in response to Unconditional GET requests. Example: $ wget -nv "http://RootCA.twca.com.tw/TWCARCA/cyber_root_revoke_2022.crl<https://urldefense.com/v3/__http://RootCA.twca.com.tw/TWCARCA/cyber_root_revoke_2022.crl__;!!J5K_pWsD!z3Fr2aGClqXaxeOCT3jrWZU43kzMh6-m1GAUa5-f-3sUaIl_WHUXRE7gg1wKf2Eax3aQP7O9LLxfhQ$>" -O /dev/stdout | openssl crl -inform der -lastupdate -nextupdate -noout 2025-03-06 14:43:17 URL:http://rootca.twca.com.tw/TWCARCA/cyber_root_revoke_2022.crl<https://urldefense.com/v3/__http://rootca.twca.com.tw/TWCARCA/cyber_root_revoke_2022.crl__;!!J5K_pWsD!z3Fr2aGClqXaxeOCT3jrWZU43kzMh6-m1GAUa5-f-3sUaIl_WHUXRE7gg1wKf2Eax3aQP7P8_QnvNA$> [719/719] -> "/dev/stdout" [1] lastUpdate=Mar 6 09:00:00 2025 GMT nextUpdate=Mar 7 08:59:59 2025 GMT Expired CRLs are being flagged because TWCA's CRL server is responding incorrectly to the Conditional GET requests that crt.sh's crl_monitor sends. Example: $ wget -nv --header="If-Modified-Since: Wed, 30 Jun 2024 21:00:00 GMT" "http://RootCA.twca.com.tw/TWCARCA/cyber_root_revoke_2022.crl<https://urldefense.com/v3/__http://RootCA.twca.com.tw/TWCARCA/cyber_root_revoke_2022.crl__;!!J5K_pWsD!z3Fr2aGClqXaxeOCT3jrWZU43kzMh6-m1GAUa5-f-3sUaIl_WHUXRE7gg1wKf2Eax3aQP7O9LLxfhQ$>" http://rootca.twca.com.tw/TWCARCA/cyber_root_revoke_2022.crl<https://urldefense.com/v3/__http://rootca.twca.com.tw/TWCARCA/cyber_root_revoke_2022.crl__;!!J5K_pWsD!z3Fr2aGClqXaxeOCT3jrWZU43kzMh6-m1GAUa5-f-3sUaIl_WHUXRE7gg1wKf2Eax3aQP7P8_QnvNA$>: 2025-03-06 14:38:40 ERROR 304: Not Modified. ________________________________ From: Chya-Hung Tsai <[email protected]> Sent: 06 March 2025 03:44 To: CCADB Public <[email protected]> Cc: Ben Wilson <[email protected]>; [email protected] <[email protected]>; Rob Stradling <[email protected]> Subject: Re: Missing or Inconsistent Disclosure of S/MIME BR Audits This Message Is From an Untrusted Sender You have not previously corresponded with this sender. Report Suspicious<https://us-phishalarm-ewt.proofpoint.com/EWT/v1/J5K_pWsD!CWYdUWf1Haq5StOq2FiXQ9er4LR3Z6Nd0cyyezsSfdO1LdRl1XvBoIxL1YkLTksAZ7otboH0aCWqF-jGQpNwGkA6Z6_mUj8$> Dear Ben, Maybe our Cross‑Certified Subordinate CA Certificate (TWCA Global Root to TWCA CYBER Root) does not include an EKU, which causes the program to also identify TWCA CYBER Root as having the capability to issue S/MIME (inheriting the capabilities of TWCA Global Root)? Additionally, our S/MIME audit report includes this Cross‑Certified Subordinate CA Certificate, but does not include the self‑signed TWCA CYBER Root, because that TWCA CYBER Root does not have the mail trust bit, and therefore the "Audits Same as Parent" flag does not apply. ChyaHung Tsai TWCA Ben Wilson 在 2025年3月6日 星期四上午10:45:39 [UTC+8] 的信中寫道： Dear ChyaHung Tsai, Could these alerts be due to the cross-signing of the roots by the TWCA Global Root CA? In the CCADB, both of these roots also appear as subordinate CAs because they are signed by the TWCA Global Root CA (it doesn't matter that they are called "roots"), so they would inherit the trust of that root, which has both trust bits indicated. I think that might be the reasoning. I'm not sure about the expiring CRL you mention. Ben On Wednesday, March 5, 2025 at 6:30:51 PM UTC-7 [email protected] wrote: Hi Rob, Thank you for providing a summary of the S/MIME BR Audit disclosure status. On behalf of TWCA, I would like to raise a few questions regarding the alerts on https://crt.sh/mozilla-disclosures<https://urldefense.com/v3/__https://crt.sh/mozilla-disclosures__;!!J5K_pWsD!yasWOllrX91fE5MB_c22RVmjkVN3I1l_ArKr0Mj1LSpP3ggyCjbi89Rf1bnsQM1ch-O2oM39ojqOiw$>: 1. [Root] TWCA CYBER Root CA is a TLS-only certificate hierarchy. In CCADB, the trust bits are only set for "website," but it appears as both "Server" and "Email" in the report. Could you clarify why? 2. Following the previous point, since this Root CA does not issue S/MIME certificates, it should not require an S/MIME Audit. Is this assumption correct? 3. [Root] TWCA Global Root CA G2 does not have TLS issuance capabilities. In CCADB, the trust bits are only set for "email," but it is displayed as both "Server" and "Email" in the report. Could you clarify why? 4. Following the previous point, since this Root CA does not issue TLS certificates, it should not require a BR or EV Audit. Is this assumption correct? 5. TWCA Global Root CA G2 has indeed cross-certified by TWCA Global Root CA. The cross-certificate (D53BF4968A7DB3C8...) has "Audits Same as Parent" checked,. Could you confirm? 6. We have noticed warnings regarding CRL expiration, but after verifying the CRLs downloaded from the CDP, they all appear to be valid. Could you confirm? 7. We observed that in the Subject CN field, only TWCA includes the word "Root," while other CAs only list Intermediate CAs. Is this a coincidence, or does TWCA need to make any adjustments? If we have misunderstood the information presented on the disclosure page or misinterpreted any CCADB attributes, please let us know. If this is confirmed as an incident, we will disclose it on Bugzilla following the latest CCADB incident reporting template. Thank you. Best regards, ChyaHung Tsai TWCA Rob Stradling 在 2025年3月6日 星期四清晨5:03:38 [UTC+8] 的信中寫道： Per the Mozilla, Apple, and Microsoft root program policies, all CA Owners with one or more Root or Intermediate CAs trusted for the issuance of S/MIME certificates should have completed an S/MIME BR audit by now and disclosed the audit details on each applicable CCADB record. I recently added tracking to https://crt.sh/mozilla-disclosures<https://urldefense.com/v3/__https://crt.sh/mozilla-disclosures__;!!J5K_pWsD!yasWOllrX91fE5MB_c22RVmjkVN3I1l_ArKr0Mj1LSpP3ggyCjbi89Rf1bnsQM1ch-O2oM39ojqOiw$> to flag missing and inconsistent disclosures of S/MIME BR audits. Since this crt.sh report is currently flagging issues for a number of CA Owners, I thought I would share a summary of the findings here. In my view, most (if not all) of these issues should be treated as incidents per https://www.ccadb.org/cas/incident-report<https://urldefense.com/v3/__https://www.ccadb.org/cas/incident-report__;!!J5K_pWsD!yasWOllrX91fE5MB_c22RVmjkVN3I1l_ArKr0Mj1LSpP3ggyCjbi89Rf1bnsQM1ch-O2oM3ofm3a4Q$>. CA Owners with Missing S/MIME BR Audit details: GoDaddy: Several applicable Root Certificate records don’t specify any S/MIME BR audit details. The WebTrust seals on https://certs.godaddy.com/repository<https://urldefense.com/v3/__https://certs.godaddy.com/repository__;!!J5K_pWsD!yasWOllrX91fE5MB_c22RVmjkVN3I1l_ArKr0Mj1LSpP3ggyCjbi89Rf1bnsQM1ch-O2oM1YytVqvg$> do not include an S/MIME BR seal. Has GoDaddy undergone an S/MIME BR audit? TWCA: No S/MIME BR audit details have been disclosed on one Root Certificate record. This root CA isn’t directly trusted for S/MIME, but it counts as S/MIME-capable because it’s cross-certified by a root that is trusted for S/MIME. Is ticking “Audits Same as Parent” the required resolution here? DigitalSign - Certificadora Digital, S.A.: Two root certificates have only the Email trust bit set in NSS, but the corresponding Root Certificate records in CCADB have no S/MIME BR audit details disclosed. Has DigitalSign undergone an S/MIME BR audit? eMudhra: Two applicable Intermediate Certificate records don’t specify any S/MIME BR audit details. Is ticking “Audits Same as Parent” the required resolution here? Entrust: Two applicable Root Certificate records don’t specify any S/MIME BR audit details. Although these roots have been distrusted for further issuance of TLS server certificates, they are still fully trusted for the issuance of S/MIME certificates. Has Entrust undergone an S/MIME BR audit? Siemens (externally-operated Sub-CAs under Entrust): Several applicable Intermediate Certificate records specify no S/MIME BR audit details. Has Siemens undergone an S/MIME BR audit? Ministerie van Defensie (externally-operated Sub-CA under PKIoverheid): One applicable Intermediate Certificate record doesn’t specify any S/MIME BR audit details. See also https://bugzilla.mozilla.org/show_bug.cgi?id=1911335<https://urldefense.com/v3/__https://bugzilla.mozilla.org/show_bug.cgi?id=1911335__;!!J5K_pWsD!yasWOllrX91fE5MB_c22RVmjkVN3I1l_ArKr0Mj1LSpP3ggyCjbi89Rf1bnsQM1ch-O2oM026d-DxA$>. LAWtrust: One applicable Root Certificate record doesn’t specify any S/MIME BR audit details. Has LAWtrust undergone an S/MIME BR audit? Cybertrust Japan (externally-operated Sub-CA under SECOM Trust Systems): One applicable Intermediate Certificate record doesn’t specify any S/MIME BR audit details. See also https://bugzilla.mozilla.org/show_bug.cgi?id=1950574<https://urldefense.com/v3/__https://bugzilla.mozilla.org/show_bug.cgi?id=1950574__;!!J5K_pWsD!yasWOllrX91fE5MB_c22RVmjkVN3I1l_ArKr0Mj1LSpP3ggyCjbi89Rf1bnsQM1ch-O2oM1CjFi7NA$>. CA Owners with Inconsistent Disclosure of S/MIME BR Audit details: Asseco Data Systems: One applicable Root Certificate record doesn’t specify any S/MIME BR audit details. Although this root certificate is not present in root stores, its signature can be validated by a doppelganger root that is. (The serial number of this self-signed root certificate appears in the CRL, but I think it’s questionable as to whether self-signed certificates can actually be revoked in this manner. This self-signed root certificate is also listed in OneCRL, but AIUI OneCRL is only applicable to Firefox’s use of TLS server certificate chains, meaning that it’s out of scope for Mozilla’s interest in S/MIME). DigiCert: Two applicable Root Certificate records don’t specify any S/MIME BR audit details. These root CAs aren’t directly trusted for S/MIME, but they do inherit S/MIME-capability via cross-certification from other DigiCert roots. (The CCADB records for the cross-certificates all specify “Audits Same as Parent”, and the corresponding parent records do specify S/MIME BR audit details). Microsec: Similar to the Asseco Data Systems case, a doppelganger Root Certificate record doesn’t specify any S/MIME BR audit details. Cybertrust Japan (externally-operated Sub-CA under SECOM Trust Systems): One applicable Intermediate Certificate record doesn’t specify any S/MIME BR audit details (see above), whereas a doppelganger Intermediate Certificate record does. See also https://bugzilla.mozilla.org/show_bug.cgi?id=1950574<https://urldefense.com/v3/__https://bugzilla.mozilla.org/show_bug.cgi?id=1950574__;!!J5K_pWsD!yasWOllrX91fE5MB_c22RVmjkVN3I1l_ArKr0Mj1LSpP3ggyCjbi89Rf1bnsQM1ch-O2oM1CjFi7NA$>. Telia: In two cases, the S/MIME BR audit Statement Date differs between a Root Certificate record and a corresponding Intermediate Certificate (cross-certificate) record. apple-disclosures I have also added tracking to https://crt.sh/apple-disclosures<https://urldefense.com/v3/__https://crt.sh/apple-disclosures__;!!J5K_pWsD!yasWOllrX91fE5MB_c22RVmjkVN3I1l_ArKr0Mj1LSpP3ggyCjbi89Rf1bnsQM1ch-O2oM2MBBqsOQ$> to flag missing and inconsistent disclosures of S/MIME BR audits. This report currently flags issues for some additional CA Owners, but since crt.sh is not yet tracking all of the intricacies of Apple’s root store metadata there may be some false positives. -- Rob Stradling Distinguished Engineer Sectigo Limited -- You received this message because you are subscribed to the Google Groups "CCADB Public" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion visit https://groups.google.com/a/ccadb.org/d/msgid/public/MW4PR17MB4729141E5B4254FBA3403E30AAD52%40MW4PR17MB4729.namprd17.prod.outlook.com.
