how to detect AIP labelling in javascript?

Question

Hi, I'm tasked with developing an Outlook web addin so that when composing an email, the addin needs to distinguish whether the attached document (Office file or PDF file) is:

• AIP labelled/encrypted
• or password protected
• or not.

As reminder, Outlook web addin runs in Javascript.

so have a few questions:

1. is AIP label a wrapping around the file, or just a header added to the header of the file?
2. if AIP label is a wrapping around the file, since password protecting is also a wrapping around the file, then when we both AIP label and password protect an Office or PDF file, will Microsoft always first wrap password then AIP, or always first wrap AIP then password, or may wrap in either order?
3. just in case, do you have any suggestion how to detect whether or not a document is AIP labelled, in Javascript?

Thanks!