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ASF subversion and git services commented on PDFBOX-2816: --------------------------------------------------------- Commit 1712040 from [~msahyoun] in branch 'pdfbox/branches/1.8' [ https://svn.apache.org/r1712040 ] PDFBOX-2816, PDFBOX-3017: don't drop AcroForm /DR for invisible signature > PDFBox makes disallowed changes when signing a signed document > -------------------------------------------------------------- > > Key: PDFBOX-2816 > URL: https://issues.apache.org/jira/browse/PDFBOX-2816 > Project: PDFBox > Issue Type: Bug > Components: Signing > Affects Versions: 1.8.9 > Reporter: Petras > Attachments: Fix_to_PDFBOX-2816.patch, acrosigned.pdf, > acrosigned_signed.pdf, acrosigned_signed_fix.pdf > > > It seems PDFBox make disallowed changes when signing a document containing a > signature with visual appearance. Using the signing example > {{org.apache.pdfbox.examples.signature.CreateSignature}} (modified to use BC > 1.52) I signed (invisible signature) a document (_acrosigned.pdf_) containing > signature with visual appearance. After signing Adobe Acrobat for the > resulted pdf (_acrosigned_signed.pdf_) shows an error for the first > signature: {quote} > 1 Page(s) Modified > Signature is invalid: > Document has been altered or corrupted since it was signed. > {quote} > The first revision is intact after signing, but it seems PDFBox made some > disallowed changes to the document. Adobe in its technical white paper [Adobe > Acrobat 9 Digital Signatures, Changes and > Improvements|http://wwwimages.adobe.com/www.adobe.com/content/dam/Adobe/en/devnet/reader/pdfs/readercomp_digitalsignatures.pdf] > disallows such changes for the signed document: > * Adding form fields other than signature fields > * Changing page content > Unfortunately, I could not identify the changes which caused this error, > though I notice these changes in structure after signing: > # Default resources (/DR) were droped from AcroForm dictionary; > # An array of annotation dictionaries (value of /Annots in page object) > became direct; > And probably there are more... > I thought the first change was fundamental, noticed that > {{PDDocument#addSignature()}} method removes /DR key for invisible > signatures. Tried to disable it in 1.8.10-SNAPSHOT sources, but unfortunately > it didn't help. Didn't tried to reuse the same array object for /Annots yet. -- This message was sent by Atlassian JIRA (v6.3.4#6332) --------------------------------------------------------------------- To unsubscribe, e-mail: dev-unsubscr...@pdfbox.apache.org For additional commands, e-mail: dev-h...@pdfbox.apache.org