12.7. Printing Encrypted PDF

When you print an encrypted PDF document from Adobe Reader to a PostScript printer like SavaPage, it creates a PostScript file that contains a notice telling the recipient that it is not permitted to convert (re-distill) it to PDF again. The ps2pdf[28] program from the Ghostscript suite respects this notice, and throws an error saying This PostScript file was created from an encrypted PDF file. Re-distilling encrypted PDF is not permitted. If, for example, an encrypted PDF allows printing only, it should not be re-distilled to a plain PDF equivalent, where all intended protection is removed.

SavaPage respects this policy. Moreover, on behalf of its users SavaPage would like its own encrypted PDF documents to be respected in the same way.

However, when an encrypted document is allowed to be printed, SavaPage would like to be able to receive it as printer, so it can be previewed and Proxy Printed. But, for that to happen we need to convert it to SafePages, i.e. to PDF format. That's where we are facing the ps2pdf barrier.

To solve this issue SavaPage has an optional workaround that ignores the PostScript notice at the point where we need the ps2pdf program to create the PDF, so SafePages can be displayed and Proxy Printed as intended.

The workaround is activated when Allow Encrypted PDF for Proxy Printing is enabled.



[28] ps2pdf is a work-alike for nearly all the functionality (but not the user interface) of Adobe's AcrobatDistiller™ product: it converts PostScript files to Portable Document Format (PDF) files, and is implemented as a command script that invokes Ghostscript. See: http://www.ghostscript.com/doc/current/Ps2pdf.htm