Hi Kirk and Ryan,

I think this points out a couple of important changes we should make to the BRs:

1) We should clarify which fields can’t have just meta data characters.  The 
statement is currently ambiguous in 2 ways:
1.1) It’s listed under “Other Subject Attributes” which implies it’s OK in any 
other field (which we know is not accurate).  This applies especially to the OU 
field that is listed above and then seems to be precluded from this requirement.
1.2) It’s not just optional fields, it should be ANY field in the subject DN. 
Although, all required fields should have clear requirements on what they MUST 
contain, it would not hurt to apply this meta data requirement to all Subject 
information fields.

2) The list of meta data characters is not spelled out clearly.  We say 
parenthetically meta data characters such as ‘.’, ‘‐‘, and ‘ ‘ (i.e. space).  I 
think there are 2 categories of content we need to specifically disallow:
2.1) Fields that consist of only meta data characters are clearly not allowed.  
I think this is the list:  ASCII 32 - 47, 58 - 64, 91 - 96,  123 – 126.  This 
is easy to specify and then audit against.
2.1) The harder one is to say don’t put nonsense into any fields like N/A, NA, 
test, “not applicable” etc.  The descriptions of all the fields in BR section 
7.1.4.2.2 items a-h are clear on the content.  Item i) OU and j) Other subject 
attributes, might need to more clearly specify what is permitted and what is 
prohibited.

The Validation WG should probably take this up.

Doug

From: Public [mailto:[email protected]] On Behalf Of Ryan Sleevi via 
Public
Sent: Friday, August 18, 2017 9:49 AM
To: Kirk Hall <[email protected]>; CA/Browser Forum Public 
Discussion List <[email protected]>
Subject: Re: [cabfpub] Question on BR BR 7.1.4.2.2(j) - Other Subject Attributes

Hi Kirk,

Your email may be confusing somethings. This is related to Entrust's issuance 
of non-BR compliant certificates, 
https://bugzilla.mozilla.org/show_bug.cgi?id=1390996 , correct? Hopefully 
you'll have a chance to reply there, even if to only acknowledge receipt and 
that Entrust is investigating.

The short answer is this language came from the Forum, because it makes sense. 
As CAs have liked to suggest that the additional subject information afforded 
by an EV and OV certificate is meaningful, and as both the Baseline 
Requirements and the EV Guidelines exist to create a common profile of fields, 
this language prohibits a practice that was previously common, of CAs 
explicitly including certain attributes in fields and putting the contents such 
as "n/a" or "-"

This is undesirable for many reasons, which the Forum recognized when 
prohibiting.
1) One goal of our requirements is to ensure certificates from different CAs 
follow a consistent profile and representation. One CA's "n/a" could be encoded 
as another CA's "-", and one CAs "NA" could mean "not applicable" could mean 
another CA's "North America". The current requirement helps ensure consistency.
2) For optional fields, there's a defined way in X.509 (and, by proxy, RFC 
5280) to how to represent that an optional field was not applicable or not 
verified - and that's simply to not include it. There is no technical 
requirement that a CA include a subject Attribute Type with an empty or 
symbolic Attribute Value; if it's not applicable, the correct approach, in all 
the relevant standards, is to simply omit this field.
3) Omitting this field, rather than filling it with 'junk' data (such as '-', ' 
', or other indicators of no applicability) helps keep certificates smaller, 
and by doing so, ensures TLS remains accessible for a broad spectrum of users 
and site operators.
4) In particular for browsers, the contents of Subject fields are displayed. 
Even in cases where a localized name for the associated Attribute Type is not 
included in the UI (e.g. Li-Chun's remarks about the EV OIDs in the context of 
Firefox and, previously, Chrome), the Attribute Value, by being an appropriate 
universal ASN.1 type, can and is displayed. That is, in the UI, you might see 
something like "1.2.3.4<http://1.2.3.4>: N/A" in the UI for an attribute type 
of OID 1.2.3.4 and an attribute value of IA5String. In order to ensure that UI 
behaviour is consistent, and that CAs do not introduce additional information 
that confuses or misleads relying parties, such prohibitions are useful.


As such, (j) serves a very important purpose, and while I appreciate your 
questions to understand its usage as well, would be very inappropriate to 
remove. More importantly, that suggestion seems to miss the first section of 
that requirement (j) - namely, that the content actually be verified by the CA. 
Were we to adopt your suggestion - fully removing (j) - then CAs would be fully 
permitted to introduce invalid, misleading information, which would be 
contained within the certificate and displayed to users, without violating the 
Baseline Requirements.

Even if we were to scope your request more narrowly, and remove simply that 
section of (j), we would be returning to the wild west of arbitrary CA 
contents, and that's undesirable.

So no, I do not believe any changes to this section are necessary, and hope 
that all CA participants are reviewing their systems to ensure compliance.


On Thu, Aug 17, 2017 at 8:54 PM, Kirk Hall via Public 
<[email protected]<mailto:[email protected]>> wrote:
There has been a discussion on a Mozilla list Certificates with Metadata-Only 
Subject Fields, 
https://groups.google.com/forum/#!topic/mozilla.dev.security.policy/Sae5lpT02Ng,
 that concerns BR 7.1.4.2.2. Subject Distinguished Name Fields:

j. Other Subject Attributes
All other optional attributes, when present within the subject field, MUST 
contain information that has
been verified by the CA. Optional attributes MUST NOT contain metadata such as 
‘.’, ‘‐‘, and ‘ ‘ (i.e. space)
characters, and/or any other indication that the value is absent, incomplete, 
or not applicable.

My question to the Forum is – where did this language come from?  An RFC?  Some 
other standard?  Does this prohibition actually make sense (especially for the 
OU field, which is optional but must be verified by the CA if it includes 
identity-type information)?  Can we consider deleting sub (j) or clarifying it 
only applies to certain fields?

Ballot 33 – Subject attribute requirements (4 August 2009)

Vote

Yes: Entrust, VeriSign, GlobalSign, DigiCert, T-Systems, QuoVadis, StartCom, 
Buypass, Trustwave, Comodo, SSC and Microsoft.

No: None.

Abstain: None.

Result: Accepted.

Motion:

Steve Roylance made the following motion, and Johnathan Nightingale and Jay 
Schiavo endorsed it:

________________________________

Motion begins

________________________________

The Guidelines should be amended by the following erratum.

________________________________

Erratum begins

________________________________

Delete the following paragraph from Section 6.



6. EV Certificate Content Requirements This section sets forth minimum 
requirements for the content of the EV Certificate as they relate to the 
identity of the CA and the Subject of the EV Certificate.



Insert the following paragraph:



6. EV Certificate Content Requirements This section sets forth minimum 
requirements for the content of the EV Certificate as they relate to the 
identity of the CA and the Subject of the EV Certificate. Optional data fields 
within the subject DN should contain either information verified by the CA or 
be left empty. Meta data such as ‘.’, ‘-‘ and ‘ ‘ characters and or any other 
indication that the field is not applicable should not be used.



Delete the following paragraph from Section 6(a)(4).



Contents These fields MUST contain information only at and above the level of 
the Incorporating Agency or Registration Agency – e.g., the Jurisdiction of 
Incorporation for an Incorporating Agency or Jurisdiction of Registration for a 
Registration Agency at the country level would include country information but 
not state or province or locality information; the Jurisdiction of 
Incorporation for the applicable Incorporating Agency or Registration Agency at 
the state or province level would include both country and state or province 
information, but not locality information; and so forth. Country information 
MUST be specified using the applicable ISO country code. State or province 
information, and locality information (where applicable), for the Subject’s 
Jurisdiction of Incorporation or Registration MUST be specified using the full 
name of the applicable jurisdiction.

Insert the following paragraph:

Contents These fields MUST contain information only relevant to the level of 
the Incorporating Agency or Registration Agency – e.g., the Jurisdiction of 
Incorporation for an Incorporating Agency or Jurisdiction of Registration for a 
Registration Agency at the country level would include country information but 
not state or province or locality information; the Jurisdiction of 
Incorporation for the applicable Incorporating Agency or Registration Agency at 
the state or province level would include both country and state or province 
information, but not locality information ; the Jurisdiction of Incorporation 
for the applicable Incorporating Agency or Registration Agency at locality 
level would include country and also state or province information where the 
state or province regulates the registration of the entities at the locality 
level. Country information MUST be specified using the applicable ISO country 
code. State or province or locality information (where applicable), for the 
Subject’s Jurisdiction of Incorporation or Registration MUST be specified using 
the full name of the applicable jurisdiction.

Delete the following paragraph from the Definitions Section.

41. Jurisdiction of Incorporation: In the case of a Private Organization, the 
country and (where applicable) the state or province where the organization’s 
legal existence was established by a filing with (or an act of) an appropriate 
government agency or entity (e.g., where it was incorporated). In the case of a 
Government Entity, the country and (where applicable) the state or province 
where the Entity’s legal existence was created by law.

Insert the following paragraph:

41. Jurisdiction of Incorporation: In the case of a Private Organization, the 
country and (where applicable) the state or province or locality where the 
organization’s legal existence was established by a filing with (or an act of) 
an appropriate government agency or entity (e.g., where it was incorporated). 
In the case of a Government Entity, the country and (where applicable) the 
state or province where the Entity’s legal existence was created by law.

________________________________

Erratum ends

________________________________
________________________________

Motion ends


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