How to find out if any PDF file is encrypted or not

Question

Hello 
 I have a requirement to read text from PDF so we have used getpdftext but if the user uploads password protected PDF file , the function getpdftext is throwing the below error- 
 Expression evaluation error at function 'getpdftext': Cannot decrypt PDF, the password is incorrect 
 If the file is password protected, I need to by pass the flow which is going to getpdftext, So Before only I need to check if the file is password protected or NOT. Can any one please suggest how to achieve this.

Mike Schmitt · Answer

There's an old archived plugin that looks like it had this capability, unfortunately it's no longer available (since maybe 10 years ago). Otherwise I know of no other ways to try() doing this. At least without using unsupported functions ;-)

Mike Schmitt · Answer

manojtumulu said: but they returned an error stating, “cannot decrypt PDF, password is incorrect” 
 Is that a halting error message? Because if it isn't, you could always just try it and return "true" if that's your result. Assuming your original request for "telling if the PDF is protected" is still relevant.

Mike Schmitt · Answer

well if it's critical, and you're ok using "unlisted" functions, maybe just build yourself a "checker rule" using the try() function. it will mainly just let you check for an error state but non-haltingly.

Mike Schmitt · Answer

That would probably be a reasonable way of handling it too without using the forbidden function - you could have a timer expire in maybe as little as 10 seconds after the subprocess fails to proceed forward (and perhaps set that subprocess to auto-expire and terminate after 5 minutes, and set its alert recipients to a dummy group or similar).

Harsha Sharma · Answer

You can explore and use any of the below plugins which includes function isPasswordProtected()& isPDFPasswordProtected() respectively to validate whether file is password protected or not. 
 Document Validation 
 Document Protection Checker

Mike Schmitt · Answer

manojtumulu said: We are specifically looking for Appian officially supported plugins 
 Appian will be quick to tell you that essentially no plug-ins are "appian supported", even the ones published by Appian. That just means they aren't liable to help you out via a support case if you have some error with one of them. You and the client should understand that "officially supported" does not mean what you think it means, and should not require you to forego needed functionality in the name of "avoiding plug-ins", as it's just more painful for everyone.