Thanks, Michael - that is exactly what I needed to know! I will take this issue up with Oracle.
I will also see if I can find some work-around to make the file acceptable to iText. Maybe I can edit the ID or re-save the file before trying to sign it, forcing the generation of a new ID....? mkl wrote: > > msinatl, > > > msinatl wrote: >> Thanks for your response. Please pardon my ignorance, but what is the >> document ID and how can I retrieve it? > > If you look at the PDF document using a text or hex viewer or a dedicated > PDF analysis tool, you'll find the trailer dictionary nearly at the end of > it. In the case of your example document > http://old.nabble.com/file/p28472754/74AA0C69-01F4-4114-6A2D-81D7E7101480-0-IDS-1-BLP.PDF > 74AA0C69-01F4-4114-6A2D-81D7E7101480-0-IDS-1-BLP.PDF : > > trailer > <</ID [ (22) (22)]/Size 4>> > > The document ID is the entryin square brackets after the /ID name, i.e. > (22) (22). This is wrong. The PDF spec ISO 32000-1:2008 states in 14.4: > > > File identifiers shall be defined by the optional ID entry in a PDF file’s > trailer dictionary (see 7.5.5, “File Trailer”). The ID entry is optional > but should be used. The value of this entry shall be an array of two byte > strings. The first byte string shall be a permanent identifier based on > the contents of the file at the time it was originally created and shall > not change when the file is incrementally updated. The second byte string > shall be a changing identifier based on the file’s contents at the time it > was last updated. When a file is first written, both identifiers shall be > set to the same value. If both identifiers match when a file reference is > resolved, it is very likely that the correct and unchanged file has been > found. If only the first identifier matches, a different version of the > correct file has been found. > > To help ensure the uniqueness of file identifiers, they should be computed > by means of a message digest algorithm such as MD5 (described in Internet > RFC 1321, The MD5 Message-Digest Algorithm. > > > At first glance, that ID of yours is wrong as it uses literal strings and > not byte strings. It additionally is likely wrong as a two-character ID > generally does not ensure uniqueness. > > On the other hand iText is wrong in assuming a length of exactly 16 bytes > in PdfEncryption.createInfoId() because the MD5 digest is merely an > example for a way to generate something unique enough. > > Regards, Michael. > > -- View this message in context: http://old.nabble.com/ArrayIndexOutOfBoundsException-when-signing-Documaker-PDF-tp28466347p28473350.html Sent from the iText - General mailing list archive at Nabble.com. ------------------------------------------------------------------------------ _______________________________________________ iText-questions mailing list iText-questions@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/itext-questions Buy the iText book: http://www.itextpdf.com/book/ Check the site with examples before you ask questions: http://www.1t3xt.info/examples/ You can also search the keywords list: http://1t3xt.info/tutorials/keywords/
