I have a PDF which i have embedded a certification signature in to the PAdES standard. My local verifier scripts, the DSS demonstration web app, and ETSI Signature checker all say the pdf signature is valid, but Adobe is showing ‘Signature is Invalid’ – Document has been altered or corrupted since it was last signed.
Can anyone see what i’ve missed or is there any tools that can show me what is wrong?
Signed PDF
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The last length value of your ByteRange value is one byte off:
/ByteRange[0 38109 78111 1077]
has to be
/ByteRange[0 38109 78111 1076]
78111 + 1077 = 79188
…while the file has only 79187 bytes.
While the file looks okay to the DSS and Conformance Checker in the first place any modification for e.g. adding revocation information via an incremental update will make the signature invalid in these applications, too.
So IMHO this is a bug in the DSS and Conformance Checker, too.
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