On Mon, Aug 20, 2018 at 9:17 AM Doug Beattie via Servercert-wg < [email protected]> wrote:
> We’re having a hard time determining the differences between the following: > > > > The CA SHALL revoke a Certificate within 24 hours if: > > 3. The CA obtains evidence that the Subscriber's Private Key corresponding > to the Public Key in the Certificate suffered a Key Compromise; or > > > > and > > > > The CA SHOULD revoke a certificate within 24 hours and MUST revoke a > Certificate within 5 days if one or more of the following occurs: > > > > 12. The CA is made aware of a vulnerability that exposes the Subscriber's > Private Key to compromise; or > > 13. The CA is made aware that the Subscriber's Private Key is being > publicly distributed in a software package. > > > > If “Subscriber's Private Key is being publicly distributed in a software > package”, isn’t that the same as #3: “obtains evidence that the > Subscriber's Private Key corresponding to the Public Key in the Certificate > suffered a Key Compromise”? > > > How do you see #12 in reality? What types of vulnerabilities do you > envision that could expose a subscribers Private Key that are not also > consistent with #3? > While this is the same argument that I've made in the past, I think the goal here is to reduce ambiguity for those that might take a tortured reading of the text. For example, at least one vendor 'obfuscated' the private key within their binary, requiring running the embedded private key through a transformation (I hesitate to say decryption, since the passphrase was itself fixed within the binary). Such a vendor might argue that the key has not been compromised until someone reverses the binary. This resolves that ambiguity by saying that the distribution within the binary itself constitutes a compromise, regardless of whether a passphrase is used. > Also, the definition of Private Key Compromise is very broad, and the > scenarios in #12 and #13 would appear to fall into “Key Compromise” which > further causes confusion about them. What constitutes a “*practical > technique*”? If we applied this definition to #12 and #13, wouldn’t > these all fall into the 24 hour rule? > > > > *Key Compromise:* A Private Key is said to be compromised if its value > has been disclosed to an unauthorized person, an unauthorized person has > had access to it, or there exists a practical technique by which an > unauthorized person may discover its value. A Private Key is also > considered compromised if methods have been developed that can easily > calculate it based on the Public Key (such as a Debian weak key, see > http://wiki.debian.org/SSLkeys) or if there is clear evidence that the > specific method used to generate the Private Key was flawed. > > > > > > Doug > > > > *From:* Public <[email protected]> *On Behalf Of *Wayne Thayer > via Public > *Sent:* Monday, August 13, 2018 4:58 PM > *To:* CA/B Forum Server Certificate WG Public Discussion List < > [email protected]> > *Cc:* CA/Browser Forum Public Discussion List <[email protected]> > *Subject:* [cabfpub] Ballot SC6 - Revocation Timeline Extension > > > > This begins the formal discussion period for ballot SC6. > > > > ========================================== > > > > Ballot SC6: Revocation Timeline Extension > > > > Purpose of Ballot: > > Section 4.9.1.1 of the Baseline Requirements currently requires CAs to > revoke a Subscriber certificate within 24 hours of identifying any of 15 > issues affecting the certificate. In cases where there is not an immediate > threat of misuse of the certificate, this requirement can cause undue harm > to a Subscriber that isn't capable of replacing the certificate prior to > revocation. This ballot makes a number of improvements to the revocation > rules imposed by the Baseline Requirements: > > * Primarily, it creates a tiered timeline for revocations. The most > critical "reasons" still require revocation within 24 hours, but for many > others 24 hours becomes a SHOULD and the CA has 5 days before they MUST > revoke. > > * A new "reason for revocation" was added to address the fact that there > is currently no requirement for CAs to revoke a certificate when requested > by the domain name registrant. After considering some more specific > language that required CAs to follow 3.2.2.4 to validate domain control, I > settled on the following more general "reason": "The CA obtains evidence > that the validation of domain authorization or control for any > Fully-Qualified Domain Name or IP address in the Certificate should not be > relied upon." > > * Reason #10 states "The CA determines that any of the information > appearing in the Certificate is inaccurate or misleading;" This ballot > removes "or misleading" because that is a subjective judgement that could > effectively be used to justify censorship, as discussed at length in > relation to the "Stripe, Inc of Kentucky" EV certificates. > > * Current reasons #11 and #13 were removed from the section on subscriber > certificates because they address cases where the intermediate and/or root > must be revoked, so there isn't much sense (and some possible harm) in > requiring revocation of all the leaf certs. > > * It requires CAs to disclose their problem reporting mechanisms in a > standard location: CPS section 1.5.2. > > * Within 24 hours of receiving a problem report, the CA is now required to > report back to both the entity reporting the problem and the Subscriber on > the CA's findings, and to work with the reporter to establish a date by > which the CA will revoke the certificate. > > > > The following motion has been proposed by Wayne Thayer of Mozilla and > endorsed by Tim Hollebeek of DigiCert and Dimitris Zacharopoulos of Harica. > > > > --- MOTION BEGINS --- > > This ballot modifies the “Baseline Requirements for the Issuance and > Management of Publicly-Trusted Certificates” as follows, based on Version > 1.6.0: > > ** Modify Section 4.9.1.1 to read as follows: ** > > The CA SHALL revoke a Certificate within 24 hours if: > > 1. The Subscriber requests in writing that the CA revoke the Certificate; > 2. The Subscriber notifies the CA that the original certificate request > was not authorized and does not retroactively grant authorization; > 3. The CA obtains evidence that the Subscriber's Private Key corresponding > to the Public Key in the Certificate suffered a Key Compromise; or > 4. The CA obtains evidence that the validation of domain authorization or > control for any Fully-Qualified Domain Name or IP address in the > Certificate should not be relied upon. > > The CA SHOULD revoke a certificate within 24 hours and MUST revoke a > Certificate within 5 days if one or more of the following occurs: > > 1. The Certificate no longer complies with the requirements of Sections > 6.1.5 and 6.1.6; > 2. The CA obtains evidence that the Certificate was misused; > 3. The CA is made aware that a Subscriber has violated one or more of its > material obligations under the Subscriber Agreement or Terms of Use; > 4. The CA is made aware of any circumstance indicating that use of a > Fully-Qualified Domain Name or IP address in the Certificate is no longer > legally permitted (e.g. a court or arbitrator has revoked a Domain Name > Registrant's right to use the Domain Name, a relevant licensing or services > agreement between the Domain Name Registrant and the Applicant has > terminated, or the Domain Name Registrant has failed to renew the Domain > Name); > 5. The CA is made aware that a Wildcard Certificate has been used to > authenticate a fraudulently misleading subordinate Fully-Qualified Domain > Name; > 6. The CA is made aware of a material change in the information contained > in the Certificate; > 7. The CA is made aware that the Certificate was not issued in accordance > with these Requirements or the CA's Certificate Policy or Certification > Practice Statement; > 8. The CA determines that any of the information appearing in the > Certificate is inaccurate; > 9. The CA's right to issue Certificates under these Requirements expires > or is revoked or terminated, unless the CA has made arrangements to > continue maintaining the CRL/OCSP Repository; > 10. Revocation is required by the CA's Certificate Policy and/or > Certification Practice Statement; > 11. The technical content or format of the Certificate presents an > unacceptable risk to Application Software Suppliers or Relying Parties > (e.g. the CA/Browser Forum might determine that a deprecated > cryptographic/signature algorithm or key size presents an unacceptable risk > and that such Certificates should be revoked and replaced by CAs within a > given period of time); > 12. The CA is made aware of a vulnerability that exposes the Subscriber's > Private Key to compromise; or > 13. The CA is made aware that the Subscriber's Private Key is being > publicly distributed in a software package. > > ** Modify section 4.9.3 as follows: ** > > The CA SHALL provide a process for Subscribers to request revocation of > their own Certificates. The process MUST be described in the CA's > Certificate Policy or Certification Practice Statement. The CA SHALL > maintain a continuous 24x7 ability to accept and respond to revocation > requests and Certificate Problem Reports. > > The CA SHALL provide Subscribers, Relying Parties, Application Software > Suppliers, and other third parties with clear instructions for reporting > suspected Private Key Compromise, Certificate misuse, or other types of > fraud, compromise, misuse, inappropriate conduct, or any other matter > related to Certificates. The CA SHALL publicly disclose the instructions > through a readily accessible online means and in section 1.5.2 of their CPS. > > ** Modify section 4.9.5 to read as follows: ** > > Within 24 hours after receiving a Certificate Problem Report, the CA SHALL > investigate the facts and circumstances related to a Certificate Problem > Report and provide a preliminary report on its findings to both the > Subscriber and the entity who filed the Certificate Problem Report. > > After reviewing the facts and circumstances, the CA SHALL work with any > entity reporting the Certificate Problem Report or other revocation-related > notice to establish a date when the CA will revoke the Certificate which > MUST not exceed the time frame set forth in Section 4.9.1.1. The date > selected by the CA SHOULD consider the following criteria: > > 1. The nature of the alleged problem (scope, context, severity, magnitude, > risk of harm); > 2. The consequences of revocation (direct and collateral impacts to > Subscribers and Relying Parties); > 3. The number of Certificate Problem Reports received about a particular > Certificate or Subscriber; > 4. The entity making the complaint (for example, a complaint from a law > enforcement official that a Web site is engaged in illegal activities > should carry more weight than a complaint from a consumer alleging that she > didn't receive the goods she ordered); and > 5. Relevant legislation. > > --- MOTION ENDS --- > > A comparison of the changes can be found at: > https://github.com/cabforum/documents/compare/master...wthayer:patch-1?short_path=7f6d14a#diff-7f6d14a20e7f3beb696b45e1bf8196f2 > > > > The procedure for approval of this ballot is as follows: > > Discussion (7+ days) > > Start Time: 2018-08-13 19:00 UTC > > End Time: Not before 2018-08-20 19:00 UTC > > Vote for approval (7 days) > > Start Time: TBD > > End Time: TBD > _______________________________________________ > Servercert-wg mailing list > [email protected] > http://cabforum.org/mailman/listinfo/servercert-wg >
_______________________________________________ Public mailing list [email protected] https://cabforum.org/mailman/listinfo/public
