On 24/11/15 05:17, Leena Soman wrote: > Hello, > I am trying to verify the timestamp in a file signed using Authenticode. > I have found that this timestamp is in the RFC3161 format. > Using openssl apis, I have parsed the Authenticode signature and reached > the oid 1.3.6.1.4.1.311.3.3.1. I have subsequently used the following apis : Am I right in understanding that you are attempting to use the OpenSSL ASN.1 APIs to parse an RFC3161 response? Did you realise that OpenSSL has APIs that support RFC3161 directly? See opensssl/ts.h as well as the "openssl ts" command line app. Matt