Luckily enough with a great help from my friend Marco Balestra, we quickly hacked an AppleScript Application that can be used to decrypt the P7M, launch the viewer, and then delete the temporary file. So the deal was to allow any user to view the files without having to deal with the Terminal. Openssl smime -decrypt -in file_in.pdf.p7m -inform DER -verify -noverify -out file_out.pdf
The command line to decode a P7M file is pretty easy: I searched a lot but wasn’t able to find a P7M viewer for Mac OS X… With Windows Acrobat Reader itself reads the P7M, while Acrobat for Mac doesn’t…, so I started investigating. Unfortunately one of the activity we dealt with required the ability of reading P7M files, that’s files that have been digitally signed and encoded in PCKS#7 SMIME Mail. The first and most important reason (the most common) is the lack of a suitable software that supports P7M among those that are installed on your device. If you cannot open the P7M file on your computer - there may be several reasons. Recently I convinced my boss in switching from Windows-based clients to Mac OS X ones. My understanding is the secured signature within the pdf is causing the issue on the phone.
