[cabfpub] [cabfman] Ballot [93] - Reasons for Revocation (BR issues 6, 8, 10, 21)

Ben Laurie benl at google.com
Wed Oct 31 11:14:45 UTC 2012


On 31 October 2012 00:02, Rick Andrews <Rick_Andrews at symantec.com> wrote:
> CAB Forum,
>
> Two questions about this ballot:
>
> 1) Does this clause about exponent checking apply to end-entity certificates, intermediate certificates, or both? The ballot is unclear.
>
> 2) I'll be honest and admit that I don't know what Ben means about coprime with phi(n). That's not in the ballot so I presume the ballot does not intend for CAs to check for that. Is that everyone else's expectation?

Just FYI, your RSA modulus n = pq, where p and q are prime. phi(n) =
(p-1)(q-1). It is a requirement of the RSA algorithm that the exponent
is coprime with this. A consequence is that the exponent must be odd,
but its a little strange requiring a check for oddness instead of the
actual required property. Or, to put it another way, there are odd
exponents that are not correct for RSA.

>
> -Rick
>
>> -----Original Message-----
>> From: Ben Laurie [mailto:benl at google.com]
>> Sent: Monday, October 29, 2012 3:07 AM
>> To: Rick Andrews
>> Cc: Robin Alden; Yngve N. Pettersen (Developer Opera Software ASA);
>> CABFMAN; Ben Wilson; public at cabforum.org
>> Subject: Re: [cabfman] [cabfpub] Ballot [93] - Reasons for Revocation
>> (BR issues 6, 8, 10, 21)
>>
>> On 26 October 2012 22:15, Rick Andrews <Rick_Andrews at symantec.com>
>> wrote:
>> > I just realized that Robin's revision seems incorrect. Yngve intended
>> that 3 would be treated as a valid exponent (I believe that's what he
>> intended), but 3 is not in the range below.
>>
>> You realise exponents have to be coprime with phi(n), right? So,
>> merely "odd" is far from sufficient.
>>
>> >
>> > -Rick
>> >
>> >> -----Original Message-----
>> >> From: public-bounces at cabforum.org [mailto:public-
>> bounces at cabforum.org]
>> >> On Behalf Of Robin Alden
>> >> Sent: Friday, October 26, 2012 3:09 AM
>> >> To: 'Yngve N. Pettersen (Developer Opera Software ASA)'; 'CABFMAN';
>> >> 'Ben Wilson'
>> >> Cc: public at cabforum.org
>> >> Subject: Re: [cabfpub] Ballot [93] - Reasons for Revocation (BR
>> issues
>> >> 6, 8, 10, 21)
>> >>
>> >> Comodo votes 'yes' based on Yngve's clarification that the effective
>> >> date would be "Immediate" and that for the RSA public exponent there
>> >> was a typo and that part of the motion should read, "The value of
>> the
>> >> public exponent MUST be an odd number equal to 3 or more, it SHOULD
>> be
>> >> in the range between
>> >> 65,537 (= (2^16)+1) and (2^256)-1."
>> >>
>> >> > -----Original Message-----
>> >> > From: public-bounces at cabforum.org [mailto:public-
>> >> > bounces at cabforum.org] On Behalf Of Yngve N. Pettersen (Developer
>> >> Opera
>> >> > Software ASA)
>> >> > Sent: 25 October 2012 16:33
>> >> > To: CABFMAN; Ben Wilson
>> >> > Cc: public at cabforum.org
>> >> > Subject: Re: [cabfpub] Ballot [93] - Reasons for Revocation (BR
>> >> issues
>> >> 6,
>> >> > 8, 10, 21)
>> >> >
>> >> >
>> >> > Opera Software votes Yes.
>> >> >
>> >> > On Thu, 18 Oct 2012 01:16:36 +0200, Ben Wilson <ben at digicert.com>
>> >> > wrote:
>> >> >
>> >> > > Ballot 93 - Reasons for Revocation (BR issues 6, 8, 10, 21)
>> >> > >
>> >> > > Yngve N. Pettersen (Opera) made the following motion, endorsed
>> by
>> >> > > Jeremy Rowley, Digicert and Robin Alden, Comodo:
>> >> > >
>> >> > > --- Motion begins ---
>> >> > >
>> >> > > Effective <DTBD>
>> >> > >
>> >> > > Erratum begins:
>> >> > >
>> >> > > A. (Issue #8)
>> >> > >
>> >> > > Add the following as 10.2.5:
>> >> > >
>> >> > > "10.2.5 Subordinate CA Private Key
>> >> > >
>> >> > > Parties other than the Subordinate CA SHALL NOT archive the
>> >> > > Subordinate CA Private Keys. If the Issuing CA generated the
>> >> Private
>> >> > > Key on behalf of the Subordinate CA, then the Issuing CA SHALL
>> >> > encrypt
>> >> > > the Private Key for transport to the Subordinate CA. If the
>> Issuing
>> >> CA
>> >> > > becomes aware that a Subordinate CA's Private Key has been
>> >> > > communicated to an unauthorized person or an organization not
>> >> > > affiliated with the Subordinate CA, then the Issuing CA SHALL
>> >> revoke
>> >> > > all certificates that include the Public Key corresponding to
>> the
>> >> > > communicated Private Key."
>> >> > >
>> >> > > B. (Issue #8)
>> >> > >
>> >> > > . Replace the heading of section 13.1.5 with "Reasons for
>> Revoking
>> >> a
>> >> > > Subscriber Certificate"
>> >> > >
>> >> > > . Add the following as section 13.1.6:
>> >> > >
>> >> > > "13.1.6 Reasons for Revoking a Subordinate CA Certificate
>> >> > >
>> >> > > The Issuing CA SHALL revoke a Subordinate CA Certificate within
>> >> seven
>> >> > > (7) days if one or more of the following occurs:
>> >> > >
>> >> > > 1. The Subordinate CA requests revocation in writing;
>> >> > >
>> >> > > 2. The Subordinate CA notifies the Issuing CA that the original
>> >> > > certificate request was not authorized and does not
>> retroactively
>> >> > > grant authorization;
>> >> > >
>> >> > > 3. The Issuing CA obtains evidence that the Subordinate CA's
>> >> Private
>> >> > > Key corresponding to the Public Key in the Certificate suffered
>> a
>> >> Key
>> >> > > Compromise or no longer complies with the requirements of
>> Appendix
>> >> > A,
>> >> > >
>> >> > > 4. The Issuing CA obtains evidence that the Certificate was
>> >> misused;
>> >> > >
>> >> > > 5. The Issuing CA is made aware that the Certificate was not
>> issued
>> >> in
>> >> > > accordance with or that Subordinate CA has not complied with
>> these
>> >> > > Baseline Requirements or the applicable Certificate Policy or
>> >> > > Certification Practice Statement;
>> >> > >
>> >> > > 6. The Issuing CA determines that any of the information
>> appearing
>> >> in
>> >> > > the Certificate is inaccurate or misleading;
>> >> > >
>> >> > > 7. The Issuing CA or Subordinate CA ceases operations for any
>> >> reason
>> >> > > and has not made arrangements for another CA to provide
>> revocation
>> >> > > support for the Certificate;
>> >> > >
>> >> > > 8. The Issuing CA's or Subordinate CA's right to issue
>> Certificates
>> >> > > under these Requirements expires or is revoked or terminated,
>> >> unless
>> >> > > the Issuing CA has made arrangements to continue maintaining the
>> >> > > CRL/OCSP Repository;
>> >> > >
>> >> > > 9. Revocation is required by the Issuing CA's Certificate Policy
>> >> > > and/or Certification Practice Statement; or
>> >> > >
>> >> > > 10. 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)."
>> >> > >
>> >> > > C. (Issue #6)
>> >> > >
>> >> > > .Replace Section 13.1.5(3) with: "(3) The CA obtains evidence
>> that
>> >> the
>> >> > > Subscriber's Private Key corresponding to the Public Key in the
>> >> > > Certificate suffered a Key Compromise (also see Section 10.2.4)
>> or
>> >> no
>> >> > > longer complies with the requirements of Appendix A,"
>> >> > >
>> >> > > .Add the following as a new Section 13.1.5(4) and renumber the
>> >> > > remaining bullet points:
>> >> > >
>> >> > > "(4) The CA obtains evidence that the Certificate was misused;"
>> >> > >
>> >> > > .Replace the definition of Key Compromise with the following:
>> >> > >
>> >> > > "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."
>> >> > >
>> >> > > D. (Issue #21)
>> >> > >
>> >> > > Add new section 13.2.7: "13.2.7 Certificate Suspension.
>> >> > >
>> >> > > The Repository MUST NOT include entries that indicate that a
>> >> > > Certificate is suspended."
>> >> > >
>> >> > > E. (Issue #10)
>> >> > >
>> >> > > Add the following after Appendix A, table (3):
>> >> > >
>> >> > > "(4) General requirements for public keys: Public keys SHOULD
>> >> follow
>> >> > > the recommendations of NIST SP 800-73-3
>> >> > > <http://csrc.nist.gov/publications/nistpubs/800-78-3/sp800-78-
>> 3.pdf
>> >> > > <http://csrc.nist.gov/publications/nistpubs/800-78-3/sp800-78-
>> >> > 3.pdf%3E
>> >> > > > >
>> >> > >
>> >> > > RSA: The value of the public exponent MUST be an odd number
>> equal
>> >> > to 3
>> >> > > or more, it SHOULD be in the range 65537 (216+1) to 2256-1."
>> >> > >
>> >> > > Erratum ends
>> >> > >
>> >> > > ... Motion ends ...
>> >> > >
>> >> > > The review period for this ballot shall commence at 21:00 UTC on
>> 17
>> >> > > October
>> >> > > 2012 and will close at 21:00 UTC on 24 October 2012. Unless the
>> >> motion
>> >> > > is withdrawn during the review period, the voting period will
>> start
>> >> > > immediately thereafter and will close at 21:00 UTC on 31 October
>> >> 2012.
>> >> > > Votes must be cast by posting an on-list reply to this thread.
>> >> > >
>> >> > > ... Motions ends ...
>> >> > >
>> >> > > A vote in favor of the motion must indicate a clear 'yes' in the
>> >> > > response.
>> >> > >
>> >> > > A vote against must indicate a clear 'no' in the response. A
>> vote
>> >> to
>> >> > > abstain must indicate a clear 'abstain' in the response. Unclear
>> >> > > responses will not be counted. The latest vote received from any
>> >> > > representative of a voting member before the close of the voting
>> >> > > period will be counted.
>> >> > >
>> >> > > Voting members are listed here:
>> >> > http://www.cabforum.org/forum.html
>> >> > >
>> >> > > In order for the motion to be adopted, two thirds or more of the
>> >> votes
>> >> > > cast by members in the CA category and one half or more of the
>> >> votes
>> >> > > cast by members in the browser category must be in favor. Also,
>> at
>> >> > > least six members must participate in the ballot, either by
>> voting
>> >> in
>> >> > > favor, voting against or abstaining.
>> >> > >
>> >> > >
>> >> >
>> >> >
>> >> > --
>> >> > Sincerely,
>> >> > Yngve N. Pettersen
>> >> > *******************************************************
>> >> > *************
>> >> > Senior Developer                 Email: yngve at opera.com
>> >> > Opera Software ASA                   http://www.opera.com/
>> >> > Phone:  +47 96 90 41 51              Fax:    +47 23 69 24 01
>> >> > *******************************************************
>> >> > *************
>> >> > _______________________________________________
>> >> > Public mailing list
>> >> > Public at cabforum.org
>> >> > https://cabforum.org/mailman/listinfo/public
>> > _______________________________________________
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