[Mimedefang] scan known-password protected ZIP files

[Pierre Dehaen]

Hi,

Is it possible to make the filter accept password protected ZIP files only when 
the password is the company's chosen (configured) one and the virus scan 
did not report any virus ? The company would then give the password to use 
to its customers/suppliers/...

I see in the man page of Archive::Zip that "The Archive::Zip module does not 
currently create or extract encrypted members." but I also see in 
clamscan/manager.c of clamav that it can scan protected zip files with a 
hard-coded password:
   char *args[] = { "unzip", "-P", "clam", "-o", NULL, NULL };
Mimedefang talks to clamd, which does not contain such a code, so I don't 
know if it is possible to do it in this case.


So the idea could be the following in mimedefang-filter:
  if (the zip file does not contain bad extensions) {
    if (contains password protected files) {
      unzip with an external unzip program and a given, hard-coded, password
      if (it works) {
        scan the files
      } else {
        reject
      }
    }
  }

Does this make sense to you ? Thanks for any feedback.
Pierre