2.1.1884 Part 4 Section 7.2.2.6, DigSig (Digital Signature)

a.   The standard does not specify the format of the digital signature blob.

Office expects that the structure of the decoded binary blob is specified as follows:

Offset in bytes

Description

0

Specifies the byte size of the digital signature data blob that starts at offset 8

4

Specifies digital signature data offset from the beginning of the blob. This shall always be 8

8

Digital signature data