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Intermediate Node Object signature data calculation RRS feed

  • Question

  • MS-FSSHTTPD 2.2.2.1 says

    Signature Data (variable): A binary item, as specified in [MS-FSSHTTPB] section 2.2.1.3, specifying a value that is unique to the file data represented by this Intermediate Node Object. The value of this item depends on the file chunking algorithm used, as specified in section 2.4.

    Section 2.4, part 2.4.1 (Zip files) very detailed explains how to calculate signatures of every chunk and corresponding Leaf Node Object, however there is no info about calculating signature of whole Intermediate Node Object.

    Tuesday, May 22, 2018 3:35 PM

Answers

  • Hey Kirill, 

    Sorry that this took so long. There were some confusions between the specification and the product functionality that I've now cleared up. The result is this: 

    Intermediate Nodes will *almost* always have zero length signature data:

    Signature Data (variable): A binary item, as specified in [MS-FSSHTTPB] section 2.2.1.3, specifying a value that is unique to the file data represented by this Intermediate Node Object. The value of this item depends on the file chunking algorithm used, as specified in section 2.4.

    In this binary item field ([MS-FSSHTTPB] 2.2.1.3) as specified above, the Length field will be zero and the Content field non-existant (they are both variable, meaning they may not exist). 

    Having said all this, some versions of the Office desktop clients (Word, PowerPoint, Excel) may write a non-zero length and have a signature written in the binary item for Intermediate Nodes. This is an historical artifact. The signature field in the [MS-FSSHTTPD] 2.2.2.1 Intermediate Node is not used and can be ignored.

    This should allow you to get past this parsing item. Let me know if something is not clear here.

    Also, I'll be filing a bug against the [MS-FSSHTTPD] document section 2.2.2.1 to clarify that the signature binary item will contain a Length of zero, no Content and that it can be ignored.

    Thanks,

    Tom



    Monday, June 11, 2018 11:00 PM
    Moderator

All replies

  • Hi Kirill, 

    Thank you for your question about MS-FSSHTTPD and calculating the signature of Intermediate Node Objects. I will look into this issue for you and respond shortly.

    Best regards,
    Tom Jebo
    Sr Escalation Engineer
    Microsoft Open Specifications

    Tuesday, May 22, 2018 11:16 PM
    Moderator
  • Hi

    Any update on this issue?

    Monday, June 4, 2018 7:01 PM
  • Hi Kirill, 

    I'm looking at it now and will update soon. Thanks for your patience.

    Tom

    Monday, June 4, 2018 7:16 PM
    Moderator
  • Hi

    Is there any chance to get some ETA?

    Monday, June 11, 2018 2:41 PM
  • Hey Kirill, 

    Sorry that this took so long. There were some confusions between the specification and the product functionality that I've now cleared up. The result is this: 

    Intermediate Nodes will *almost* always have zero length signature data:

    Signature Data (variable): A binary item, as specified in [MS-FSSHTTPB] section 2.2.1.3, specifying a value that is unique to the file data represented by this Intermediate Node Object. The value of this item depends on the file chunking algorithm used, as specified in section 2.4.

    In this binary item field ([MS-FSSHTTPB] 2.2.1.3) as specified above, the Length field will be zero and the Content field non-existant (they are both variable, meaning they may not exist). 

    Having said all this, some versions of the Office desktop clients (Word, PowerPoint, Excel) may write a non-zero length and have a signature written in the binary item for Intermediate Nodes. This is an historical artifact. The signature field in the [MS-FSSHTTPD] 2.2.2.1 Intermediate Node is not used and can be ignored.

    This should allow you to get past this parsing item. Let me know if something is not clear here.

    Also, I'll be filing a bug against the [MS-FSSHTTPD] document section 2.2.2.1 to clarify that the signature binary item will contain a Length of zero, no Content and that it can be ignored.

    Thanks,

    Tom



    Monday, June 11, 2018 11:00 PM
    Moderator