[liberationtech] Metadata Cleanup trough File Format Convertion?

[Fabio Pietrosanti (naif)]

Hi all,

i've been thinking about the topic of metadata cleanup of files from an 
implementation point of view.

Regardless the consideration whether it's something useful or not for a 
Whistleblowing platform (GlobaLeaks), i've been considering whenever the 
"Metadata Cleanup" can't be approached by "File Format Conversion".

If i'd like to remove metadata from various documents formats (pdf, 
word, ppt, excel, etc) or image file, i've been thinking that rather 
then "explicitly removing metadata" a possible different approach would 
be by doing a "file convertion" .

If a JPEG is converted to PNG, "maybe" all metadatas are lost. (this has 
to be verified)
If a DOC/DOCX is converted to a PDF, maybe all metadatas are lost.

At GlobaLeaks we've been discussing about introducing "metadata cleanup" 
[1] , but also a "file sterilization" [2] with the goal to protect 
Receivers of a Whistleblowing site against targeted 0day attacks.

Should we approach "metadata cleanup" by doing the "file sterilization" 
processing trough existing Libreoffice convertion API [3] to save 
engineering effort/time?


[1] Metadata Cleanup https://github.com/globaleaks/GlobaLeaks/issues/305
[2] File Sterilization https://github.com/globaleaks/GlobaLeaks/issues/270
[3] Libreoffice Convertion API https://github.com/dagwieers/unoconv

-- 
Fabio Pietrosanti (naif)
HERMES - Center for Transparency and Digital Human Rights
http://logioshermes.org - http://globaleaks.org - http://tor2web.org