I am Indian and in small business of adhaar card and I can't open the singed PDF document in adobe reader in Ubuntu 12.04.3 LTS and there is no alternative that open PDF and validate the signature. So anybody tell me what to do and how to ?
I had the same problem. You need to install Adobe Reader to validate signature of aadhar card, because the signature validation implementation is specifically done in Adobe Reader only. Use this question to install Adobe Reader How to Install Adobe Acrobat in Ubuntu 16.04?
Once you install it you should be able to validate signature of aadhar card as per instructions provided at https://eaadhaar.uidai.gov.in/#