3 Replies Latest reply on May 5, 2011 6:05 AM by csaba818

    PDF signature timestamp problem

    csaba818

      Hi, sorry if this post is slightly offtopic.

       

      We are trying to sign and timestamp pdf documents in java (using Apache PDFBox) and we are stuck with a problem for more than a week. The signature itself is good, Adobe Reader can validate it succesfully (after adding our self signed test root certificate to trusted certificates). The problem is with the timestamp. Adobe Reader says that the signature is timestamped, but the timestamp could not be verified. If I look at the Date/Time tab on the Signature Properties window the Timestamp Authority field says Not available. Older versions of Adobe Reader 9 displayed the Show Certificate button for the Timestamp Authority as enabled, and if I clicked it, the Reader crashed. In newer Reader 9 versions and in Reader X the button is disabled. It seems Reader recognises the timestamp but can't extract the TSA certificate.

      However if I sign the pdf with Acrobat X Pro or with iText (using the same private key and the same TSA) everything is perfect, the timestamp is validated, Timestamp Authority field shows the correct value, TSA certifiicate is OK.

      I analyzed the signatures and the timestamp tokens, but I could not find any significant difference between the good and wrong ones.

       

      I wanted to attach a working and a non-working sample but I didn't find how to do that.

       

      Could someone please give us some advice about what could cause something like this?

      Can Reader log the signature parsing/validating process to view what's wrong?

       

      Thanks in advance

      Csaba