Re: IDS> Revised HCD-NAP Binding Document Available

From: Randy Turner (rturner@amalfisystems.com)
Date: Fri Oct 17 2008 - 02:28:41 EDT

  • Next message: Ron.Bergman@ricoh-usa.com: "IDS> Agenda for Thursday's (10/23) Meeting"

    Hi All,

    Just so we're clear, the software version numbers (major, minor, build
    #, service pack #s) are
    octets, but they would be encoded in "binary", so these values are
    allowed to grow to very large numbers...

    The major, minor, and build numbers can be 0 to 2^32 - 1 and the
    service pack numbers can be 0 to 2^16 - 1.

    There was an earlier question about version numbers "not fitting" into
    these fields, but as described in the
    existing NEA PA-TNC "Numeric Version" attribute type, they tried to
    make sure to cover the worst case.

    Best Regards,
    Randy

    On Oct 16, 2008, at 9:34 PM, William A Wagner wrote:

    > Yoshimura-san and list,
    >
    > Thank you for your comments. The feedback from readers allows the
    > Working
    > Group to improve the clarity of the specfication
    >
    > Supplementing Randy's general observations, I will attempt to answer
    > your
    > questions based upon the information in the document. I request that
    > WG
    > members that see errors in my analysis please correct them, and
    > perhaps take
    > this as an opportunity to make the spec a little better.
    >
    >> Q1. Section 4.4 HCD Attribute Encoding
    >> C. VALUE FIELD is fixed size (4octet) or variable size ?
    >> 2. SUB-TLV FIELD is fixed size (8bit) or variable size ?
    >
    >> <WW>< SUB-TLV FIELD is of variable size. Section 4.4 describes the
    >> format
    > used to encode the HCD attributes, basically embedding a Sub-TVL field
    > specific to the attribute within the Value field of a fixed format TLV
    > structure. The size of the sub-TLV fields are identified with the
    > descriptions of the attributes formats in paragraphs 4.5, 4.6 and
    > 4.7. The
    > lengths of the sub TLV fields vary significantly among attributes
    > and are in
    > themselves variable for certain attributes.
    >
    >> Q2. Section 4.6.4 HCD DOWNLOADABLE AP NAME SUB-TLV (Sub-Type = 7,
    >> Sub-Length =variable)
    >> 2.Downloadable Application Name (4 octets)
    >> We suppose the length of Downloadable Application Name should be
    >> variable.
    >
    >> <WW>< I agree that this is confusing. The length of the sub TLV is
    > indicated as variable, but the constituent parts are defined as of
    > fixed
    > length. What are we missing here?
    >
    >
    >>
    >> Q3. Section 4.6.12 HCD CERTIFICATION STATE SUB-TLV (Sub-Type =
    >> 14, Sub-Length = 4octets)
    >>
    >> In wd-idsattributes10-20081013, Section 4.1 General Attribute
    >> Definitions
    >> HCD_Certification_State
    >> "Since it is being deferred to Phase 2 of the IDS definition
    >> process."
    >>
    >> This attribute is not yet defined clearly and being deferred to
    >> Phase2.
    >> Could you let us know when this attribute will be defined ?
    >
    >> <WW>< This depends upon the progress in phase 1, as well as the
    >> perceived
    > need for this attribute. I am not aware of a strong demand for it at
    > this
    > time.
    >
    >
    >
    >> Q4. 4.7.1 HCD CONFIGURATION STATE SUB-TLV (Sub-Type = 15, Sub-
    >> Length = 4octets)
    >> This attribute is not yet defined clearly.
    >> Could you let us know when this attribute will be defined ?
    >
    >> <WW>< As is indicated in the spec, this is a vendor specific value
    >> and will
    > not be defined in the standard. This could be a bit map indicating
    > the value
    > of a group of settings or it could be derived by some complex
    > algorithm.
    > However, it is necessary that a given value always refer to a given
    > set of
    > configuration settings (considering the configuration elements
    > included in
    > the attribute). The primary intent of the value is to indicate that
    > some
    > setting has been changed, not necessarily to identify what the
    > setting was
    > for or what the value was.
    >
    >
    >
    >> Q5. 4.6.1 HCD FIRMWARE VERSION SUB-TLV (Sub-Type = 5, Sub-Length =
    >> 16 octets)
    >> 4.6.5 HCD DOWNLOADABLE AP VERSION SUB-TLV (Sub-Type = 8, Sub-Length
    >> = 20 octets)
    >> 4.6.9 HCD RESIDENT AP VERSION SUB-TLV (Sub-Type = 11, Sub-Length =
    >> 16 octets)
    >> The format of VERSION is defined as fixed format.
    >> 1. Major Version Number (4 octets)
    >> 2. Minor Version Number (4 octets)
    >> 3. Build Number (4 octets)
    >> 4. Service Pack, Major Number (2 octets)
    >> 5. Service Pack, Minor Number (2 octets)
    >>
    >> However, some firmware or applications version numbers may not fit
    >> to the specified format.
    >> In such case, is it possible to apply the following rules ?
    >> If the version number is longer than 16 octets, use only the first
    >> 16 octets.
    >> If the version number is shorter than 16 octets, the rest of data
    >> are filled with 0x00.
    >
    >> <WW>< Note the comment for each of the attributes you identify that
    >> "This
    > attribute MUST be included only if the HCD [FIRMWARE] String SUB-
    > TLV is not
    > present.". My understanding is that, if the firmware has a name and
    > complex
    > version identification, it can be entered in the HCD FIRMWARE
    > VERSION STRING
    > SUB-TLV, DOWNLOADABLE AP NAME SUB-TLV or HCD RESIDENT AP NAME SUB-TLV
    > variable length strings. The specified fixed format for the version
    > could be
    > used as an alternative. And to the extent that the manufacturer can
    > identify
    > this firmware as he wishes, he could modify the version
    > identification to
    > follow this format. But as Randy indicated, the version
    > identification must
    > be unique to a given version of code.
    >
    >
    > Hope this helps.
    >
    > Bill Wagner
    >
    > -----Original Message-----
    > From: owner-ids@pwg.org [mailto:owner-ids@pwg.org] On Behalf Of
    > Randy Turner
    > Sent: Thursday, October 16, 2008 1:44 AM
    > To: Tomonari Yoshimura
    > Cc: ids@pwg.org
    > Subject: Re: IDS> Revised HCD-NAP Binding Document Available
    >
    >
    > Hello Yoshimura-san and list,
    >
    > Since the Microsoft SOH is one of two possible ways to carry
    > attributes (the other being the pure TNC/NEA protocol), it seems like
    > the IETF or TCG will have to provide
    > a mapping document to make sure that the two protocols are able to
    > convey the attributes (and their corresponding datatypes) in an
    > interoperable fashion. Which means
    > there may be a "mapping document" like the one the IDS is working on
    > that will be coming from "somewhere", possibly a separate document, or
    > an informational appendix
    > in one of the two transport documents (MS-SOH or NEA )
    >
    > Also, since the NEA working group did not reach consensus on the HCD
    > CONFIGURATION STATE attribute, we will need to reserve a place for
    > this in our own PWG/IDS
    > extensible attribute list that we should be building. (These will
    > have to be under the PWG SMI tree)
    >
    > On the question of version numbers, a vendor can choose whatever
    > method of version logic is required, just so it fits within the data
    > types specified. The only operational
    > requirement is that the "version logic" should allow a device to
    > UNIQUELY express software module version numbers, and that these
    > version numbers are UNIQUE-enough
    > to allow remediation - so the remediation system must understand the
    > same vendor-specific version logic.
    >
    > Because of the unique-ness requirement, if you only use the first 16
    > octets of a version number, then these 16 octets MUST be unique across
    > all past and future software
    > releases. At least that's the only way I know to allow robust
    > remediation.
    >
    > Best Regards,
    > Randy
    >
    >
    >
    > On Oct 15, 2008, at 9:58 PM, Tomonari Yoshimura wrote:
    >
    >> Dear PWG-IDS Members,
    >>
    >> We have read through "wd-ids-napsoh10-20081008.pdf" and
    >> would like to confirm the items listed below.
    >> Could you kindly let us know answers or comments on our questions ?
    >>
    >> Q1. Section 4.4 HCD Attribute Encoding
    >> C. VALUE FIELD is fixed size (4octet) or variable size ?
    >> 2. SUB-TLV FIELD is fixed size (8bit) or variable size ?
    >>
    >> Q2. Section 4.6.4 HCD DOWNLOADABLE AP NAME SUB-TLV (Sub-Type = 7,
    >> Sub-Length =variable)
    >> 2.Downloadable Application Name (4 octets)
    >> We suppose the length of Downloadable Application Name should be
    >> variable.
    >>
    >> Q3. Section 4.6.12 HCD CERTIFICATION STATE SUB-TLV (Sub-Type =
    >> 14, Sub-Length = 4octets)
    >>
    >> In wd-idsattributes10-20081013, Section 4.1 General Attribute
    >> Definitions
    >> HCD_Certification_State
    >> "Since it is being deferred to Phase 2 of the IDS definition
    >> process."
    >>
    >> This attribute is not yet defined clearly and being deferred to
    >> Phase2.
    >> Could you let us know when this attribute will be defined ?
    >>
    >> Q4. 4.7.1 HCD CONFIGURATION STATE SUB-TLV (Sub-Type = 15, Sub-
    >> Length = 4octets)
    >> This attribute is not yet defined clearly.
    >> Could you let us know when this attribute will be defined ?
    >>
    >> Q5. 4.6.1 HCD FIRMWARE VERSION SUB-TLV (Sub-Type = 5, Sub-Length =
    >> 16 octets)
    >> 4.6.5 HCD DOWNLOADABLE AP VERSION SUB-TLV (Sub-Type = 8, Sub-Length
    >> = 20 octets)
    >> 4.6.9 HCD RESIDENT AP VERSION SUB-TLV (Sub-Type = 11, Sub-Length =
    >> 16 octets)
    >> The format of VERSION is defined as fixed format.
    >> 1. Major Version Number (4 octets)
    >> 2. Minor Version Number (4 octets)
    >> 3. Build Number (4 octets)
    >> 4. Service Pack, Major Number (2 octets)
    >> 5. Service Pack, Minor Number (2 octets)
    >>
    >> However, some firmware or applications version numbers may not fit
    >> to the specified format.
    >> In such case, is it possible to apply the following rules ?
    >> If the version number is longer than 16 octets, use only the first
    >> 16 octets.
    >> If the version number is shorter than 16 octets, the rest of data
    >> are filled with 0x00.
    >>
    >> Thanks in Advance.
    >>
    >> ________________________________
    >>
    >> From: owner-ids@pwg.org [mailto:owner-ids@pwg.org] On Behalf Of
    > Ron.Bergman@ricoh-usa.com
    >> Sent: Thursday, October 09, 2008 2:26 AM
    >> To: ids@pwg.org
    >> Subject: IDS> Revised HCD-NAP Binding Document Available
    >>
    >>
    >>
    >> The latest version can be found at:
    >>
    >> ftp://ftp.pwg.org/pub/pwg/ids/wd/wd-ids-napsoh10-20081008.pdf (.doc)
    >>
    >> A version with the changes highlighted is also available at:
    >>
    >> ftp://ftp.pwg.org/pub/pwg/ids/wd/wd-ids-napsoh10-20081008-rev.pdf
    >>
    >> We will discuss the changes and open issues at the Face to Face
    >> meeting in Lexington.
    >>
    >> Items for discussion:
    >>
    >> 1. The Conformance section (5) needs work.
    >> 2. Joe Murdock will provide information regarding the required NAP
    >> protocols.
    >>
    >>
    >>
    >
    >



    This archive was generated by hypermail 2.1.4 : Fri Oct 17 2008 - 02:28:49 EDT