As placeholder in the Mozilla Root Store Policy, I'm proposing the following sentence for section 6.1 - "A CA MUST ensure that it populates the CCADB with the appropriate 'full CRL' in the CCADB revocation information field pertaining to certificates issued by the CA <https://www.ccadb.org/cas/fields#revocation-information> for each intermediate CA technically capable of issuing server certificates." (The hyperlink isn't active yet until we have the CCADB language and implementation clarified, per Kathleen's recent email and responses thereto.) Here it is on GitHub - https://github.com/BenWilson-Mozilla/pkipolicy/commit/26c1ee4ea8be1a07f86253e38fbf0cc043e12d48. Caveat - other browsers, such as Apple, will likely have more encompassing implementation requirements for when to populate these "full CRL" fields.
On Mon, Jan 25, 2021 at 10:16 AM Aaron Gable <aa...@letsencrypt.org> wrote: > I think that an explicit carve-out for time-scoped CRLs is a very good > idea. > > In the case that this change to the MRSP is adopted, I suspect that LE > would scope CRLs by notAfter quite tightly, with perhaps one CRL per 24 or > even 6 hours of issuance. We would pick a small interval such that we could > guarantee that each CRL would still be a reasonable size even in the face > of a mass revocation event. > > Producing CRLs at that rate, it would be very valuable to be able to > gracefully age CRLs out once there is no possibility for a revocation > status update for any certificate in their scope. > > Aaron > > On Sun, Jan 24, 2021 at 10:22 AM Ben Wilson via dev-security-policy < > dev-security-policy@lists.mozilla.org> wrote: > >> All, >> >> Another suggestion came in for clarification that hasn't been raised on >> the >> list yet, so I'll try and explain the scenario here. >> >> Normally, a CA must publish and update its CRLs until the end of the CA >> certificate's expiration. However, I think that some CAs partition their >> CRLs based on issuance time, e.g., all certificates issued during January >> 2021. And all of those certificates would expire after the applicable >> validity period. I think CAs don't continue to regenerate or reissue >> those >> types of partitioned CRLs which only contain certificates that have >> expired. So maybe we need to add an express exception that allows CAs to >> omit those obsolete CRLs from the JSON file -- as long as the JSON file >> contains the equivalent of a "full and complete" CRL. >> >> Thoughts? >> >> Thanks, >> Ben >> >> >> On Wed, Jan 13, 2021 at 8:57 AM Rob Stradling <r...@sectigo.com> wrote: >> >> > Hi Ben. >> > >> > > *A CA technically capable of issuing server certificates MUST ensure >> > that >> > > the CCADB field "Full CRL Issued By This CA" contains either the URL >> for >> > > the full and complete CRL or the URL for the JSON file containing all >> > URLs >> > > for CRLs that when combined are the equivalent of the full and >> complete >> > CRL* >> > >> > As a consumer of this data (crt.sh), I'd much prefer to see "Full CRL >> > Issued By This CA" and "the URL for the JSON file" as 2 separate fields >> in >> > the CCADB. CAs would then be expected to fill in one field or the >> other, >> > but not both. Is that possible? >> > >> > To ensure that these JSON files can be programmatically parsed, I >> suggest >> > specifying the requirement a bit more strictly. Something like this: >> > "...or the URL for a file that contains only a JSON Array, whose >> > elements are URLs of DER encoded CRLs that when combined are the >> equivalent >> > of a full and complete CRL" >> > >> > > I propose that this new CCADB field be populated in all situations >> where >> > the CA is enabled for server certificate issuance. >> > >> > Most Root Certificates are "enabled for server certificate issuance". >> > Obviously CAs shouldn't issue leaf certs directly from roots, but >> > nonetheless the technical capability does exist. However, currently CAs >> > can't edit Root Certificate records in the CCADB, which makes populating >> > these new field(s) "in all situations" rather hard. >> > >> > Since OneCRL covers revocations of intermediate certs, may I suggest >> that >> > CAs should only be required to populate these new field(s) in >> intermediate >> > certificate records (and not in root certificate records)? >> > >> > Relatedly, "A CA technically capable of...that the CCADB field" seems >> > wrong. CCADB "CA Owner" records don't/won't contain the new field(s). >> > Similar language elsewhere in the policy (section 5.3.2) says "All >> > certificates that are capable of being used to..." (rather than "All >> > CAs..."). >> > >> > Technically-constrained intermediate certs don't have to be disclosed to >> > CCADB, but "in all situations where the CA is enabled for server >> > certificate issuance" clearly includes technically-constrained >> > intermediates. How would a CA populate the "Full CRL Issued By This CA" >> > field for a technically-constrained intermediate cert that has >> > (legitimately) not been disclosed to CCADB? >> > >> > ------------------------------ >> > *From:* dev-security-policy < >> dev-security-policy-boun...@lists.mozilla.org> >> > on behalf of Ben Wilson via dev-security-policy < >> > dev-security-policy@lists.mozilla.org> >> > *Sent:* 08 January 2021 01:00 >> > *To:* mozilla-dev-security-policy < >> > mozilla-dev-security-pol...@lists.mozilla.org> >> > *Subject:* Policy 2.7.1: MRSP Issue #218: Clarify CRL requirements for >> > End Entity Certificates >> > >> > CAUTION: This email originated from outside of the organization. Do not >> > click links or open attachments unless you recognize the sender and know >> > the content is safe. >> > >> > >> > This is the last issue that I have marked for discussion in relation to >> > version 2.7.1 of the Mozilla Root Store Policy >> > < >> > >> https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.mozilla.org%2Fen-US%2Fabout%2Fgovernance%2Fpolicies%2Fsecurity-group%2Fcerts%2Fpolicy%2F&data=04%7C01%7Crob%40sectigo.com%7C65685639e2bf45be5f6f08d8b370cf17%7C0e9c48946caa465d96604b6968b49fb7%7C0%7C0%7C637456644391892862%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=shOhNu8IGrT0iSSt2LY4E6LQlsr6y435Vv%2BNezNCh98%3D&reserved=0 >> > >. >> > It is identified and discussed in GitHub Issue #218 >> > < >> > >> https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub.com%2Fmozilla%2Fpkipolicy%2Fissues%2F218&data=04%7C01%7Crob%40sectigo.com%7C65685639e2bf45be5f6f08d8b370cf17%7C0e9c48946caa465d96604b6968b49fb7%7C0%7C0%7C637456644391892862%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=Zb0abofrs3IaJzX9nkEnFf6RbyCemLYIi%2B7l4SmUz5U%3D&reserved=0 >> > >> > for the MRSP. >> > >> > I will soon update everyone on the status of the other 13 discussion >> items >> > already presented, as some of them are in need of revision based on >> > comments received thus far. >> > >> > While subsection (b) of section 7.1.2.3 of the Baseline Requirements >> makes >> > a cRLDistributionPoint (CDP) in end entity certificates optional, >> Mozilla >> > still desires that CRL-based revocation information be available because >> > CRLite uses CRLs to construct its revocation filters. (Apple also uses >> > such CRL information in its certificate validation processes and, as I >> > understand, is making a similar request of CAs with respect to the new >> > CCADB field, discussed below.) >> > >> > While all such CRL information is needed, large CRLs are disfavored >> because >> > of the time they take to download and process. Thus, CAs shard, >> partition, >> > or "scope" their CRLs into smaller chunks. Section 5 of RFC 5280 >> explains, >> > "Each CRL has a particular scope. The CRL scope is the set of >> certificates >> > that could appear on a given CRL. … A complete CRL lists all unexpired >> > certificates, within its scope, that have been revoked for one of the >> > revocation reasons covered by the CRL scope. A *full and complete CRL* >> > lists all unexpired certificates issued by a CA that have been revoked >> for >> > any reason." (Emphasis added.) >> > >> > There is a new field in the CCADB for CAs to include information needed >> for >> > browsers or others to construct a "full and complete CRL", i.e. to >> gather >> > information from CAs that don't include the CRL path to their "full and >> > complete CRL" in end entity certificates they issue. This new CCADB >> field >> > is called "Full CRL Issued By This CA" and is located under the heading >> > "Pertaining to Certificates Issued by this CA." Rather than condition >> the >> > requirement that CAs fill in this information in the CCADB only when >> they >> > don't include a CDP to a full and complete CRL, I propose that this new >> > CCADB field be populated in all situations where the CA is enabled for >> > server certificate issuance. In cases where the CA shards or partitions >> its >> > CRL, the CA must provide a JSON-based list of CRLs that when combined >> are >> > the equivalent of the full and complete CRL. >> > >> > Proposed language to add to section 6 of the Mozilla Root Store Policy >> is >> > as follows: >> > >> > *CAs SHOULD place the URL for the associated CRL within the >> > crlDistributionPoints extension of issued certificates. A CA MAY omit >> the >> > crlDistributionPoint extension, if permitted by applicable requirements >> and >> > policies, such as the Baseline Requirements. * >> > >> > *A CA technically capable of issuing server certificates MUST ensure >> that >> > the CCADB field "Full CRL Issued By This CA" contains either the URL for >> > the full and complete CRL or the URL for the JSON file containing all >> URLs >> > for CRLs that when combined are the equivalent of the full and complete >> > CRL* >> > . >> > >> > >> > I look forward to your comments and suggestions. >> > >> > Ben >> > _______________________________________________ >> > dev-security-policy mailing list >> > dev-security-policy@lists.mozilla.org >> > >> > >> https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.mozilla.org%2Flistinfo%2Fdev-security-policy&data=04%7C01%7Crob%40sectigo.com%7C65685639e2bf45be5f6f08d8b370cf17%7C0e9c48946caa465d96604b6968b49fb7%7C0%7C0%7C637456644391892862%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=%2B3uVDNUQ7qJ1afOf7O6zDkwVB8HrEiqrQSPdVir0A88%3D&reserved=0 >> > >> _______________________________________________ >> dev-security-policy mailing list >> dev-security-policy@lists.mozilla.org >> https://lists.mozilla.org/listinfo/dev-security-policy >> > _______________________________________________ dev-security-policy mailing list dev-security-policy@lists.mozilla.org https://lists.mozilla.org/listinfo/dev-security-policy
