Handle unsupported digest algorithm in Adobe Reader plugin

Hi there.

I was creating a plugin for signature validating. The problem is that signature uses third party digest algorithm  "GOST34311". I think Adobe simply does not recognize such algorithm. I tried to catch the exception in this function:

void DSEngine::sigValidate( PSSigValidateParams params );

but it doesn't even get there, exception is thrown before.

So, how can I get algorithm name and handle any custom digest algorithm? Please, give some approach.

Thanks in advance!