Custom digital signature algorithm

[sayat2002s66071132]

I was able to sign a pdf document with GOST algorithm, but Adobe Reader

throws exception while validating the signature, because the GOST algorithm

is not supported. How can I validate it in any way? What should I do to add

the algorithm to Adobe Reader? Can I make it by means of plugin?

[AnandSri]

Hello Sayat,

The GOST algorithm is not supported in Adobe Reader. If you want to create custom signatures, then Custom Signatures are handled through Acrobat SDK API and accompanying files. Download the Acrobat SDK with sample files and plug-ins Adobe - Acrobat Developer Center | Adobe Developer Connection

You can also check with our expert in Acrobat SDK forums Acrobat SDK

Feel free to update this discussion for any further assistance.

Thanks,

Anand Sri.

[sayat2002s66071132]

Thank you for reply.

I'm trying to run the simplest plugin from samples in SDK: "BasicPlugin.api", but it throws exception like "Invalid plugin detected. Adobe Reader will quit". The project compiles without any problem in VS 2010 an VS 2017. I'm using Adobe Reader XI version 11.0.0. Any license required to build and run plugins?

[Bernd Alheit · Accepted solution]

For Adobe Reader you need this:

Adobe Reader Integration Key License (RIKLA) Program

Use Adobe Acrobat for the development of plug-ins.

[sayat2002s66071132]

How can I get encryption and digest algorithms here?

void DSEngine::sigValidate( PSSigValidateParams params )

if algorithms are not supported by default.

Thank you!

[lrosenth]

It is not just that GOST is not supported by Adobe Reader, it is not defined by the PDF standard (ISO 32000) so any use of it is “out of spec”.

In order to have it work in Reader, you would need to write a custom signature handler plugin – which (as noted by Bernd) requires a license from Adobe.

[sayat2002s66071132]

Thank you sir. Your answer makes things clear.

Can you give any approach to adding custom encryption algorithms?

Thank you.