Signed PDF info

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   Hi,
I can't seem to find the function to determine if a PDF is digitally signed and the function to retrieve digital signature information to display to the user. I would like to display some information from what Adobe Reader displays in the Signatures panel.

Thanks!

Edited by Chopinke - 19 Feb 16 at 3:51PM

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Chopinke Members Profile Find Members Posts Team Player Joined: 29 Apr 14 Status: Offline Points: 24	Post Options Post Reply Quote Chopinke Report Post Thanks(0) Quote Reply Topic: Signed PDF info Posted: 19 Feb 16 at 3:51PM
	Hi, I can't seem to find the function to determine if a PDF is digitally signed and the function to retrieve digital signature information to display to the user. I would like to display some information from what Adobe Reader displays in the Signatures panel. Thanks! Edited by Chopinke - 19 Feb 16 at 3:51PM

Ingo Members Profile Find Members Posts Moderator Group Joined: 29 Oct 05 Status: Offline Points: 3530	Post Options Post Reply Quote Ingo Report Post Thanks(0) Quote Reply Posted: 19 Feb 16 at 8:16PM
	Hi, actually there isn't a function to check if there's an existing signature but you can do it yourself. There are always some special tags in the pdf-source if there's an existing signature. You can read the complete pdf-file from disc into a string. Then you can convert it (for better search results) to upper cases. Then you can search (with "Pos") for these special signatures. I've done it with Delphi XE5 but you can do it similar with any other language. // . . . textkomplett := LoadFileToStr2(FName); uppercontent := UpperCase(textkomplett); If ( ( ( Pos('/TYPE /SIG', uppercontent) > 0 ) and ( Pos('/FT /SIG', uppercontent) > 0 ) ) or ( ( Pos('/TYPE/SIG', uppercontent) > 0 ) and ( Pos('/FT/SIG', uppercontent) > 0 ) ) or ( Pos('/SIGFLAGS', uppercontent) > 0 ) ) Then sign_ja := '1'; // . . .
	Cheers, Ingo

Chopinke Members Profile Find Members Posts Team Player Joined: 29 Apr 14 Status: Offline Points: 24	Post Options Post Reply Quote Chopinke Report Post Thanks(0) Quote Reply Posted: 22 Feb 16 at 7:51AM
	Thanks for the info, so it has to be manually. I found a reference: https://www.adobe.com/devnet-docs/acrobatetk/tools/DigSig/Acrobat_DigitalSignatures_in_PDF.pdf I am working with DXE7, so I need to find a way to also verify the substring DSS.