There may be multiple ranges but the crypto plugins shipped with Acrobat
don't like more than two. Don't ask me why.

Paulo

----- Original Message -----
From: "Martin Brunecky" <mbrunecky@(protected)>
To: <itext-questions@(protected)>
Sent: Wednesday, June 13, 2007 11:38 PM
Subject: [iText-questions] Suspicious data: SigDict /ByteRange value


>
>
> Gentlemen:
>
> Continuing my efforts to use USPS EPM TSA (time-stamp-autority), I am
> running into another difficulty:
>
>
>
> I am using (Java version) of example (as Paolo kindly directed me):
>
> http://itextpdf.sourceforge.net/howtosign.html#signextitextsharp.
>
>
>
> I would like to be able to EXCLUDE some other (than /Content) part of my
> signature from the digest computation.
>
> I am using the above example and the following code works just fine. I get
> a
> good PDF file and my Adobe Reader is happy with my signature.
>
>
>
> But when I try to exclude an additional byte range (I uncomment the lines
> marked //HERE below), the Reader (7.0) reports:
>
>  Error during signature verification
>
>  Signature contains incorrect, unrecognized, corrupted or suspicious data
>
>  Support information: SigDict /ByteRange value
>
>
>
>
>
>        PdfReader reader = new PdfReader(srcFile);
>
>        FileOutputStream fout = new FileOutputStream(dstFile);
>
>        PdfStamper stp = PdfStamper.createSignature(reader, fout,
> '\0');
>
>        PdfSignatureAppearance sap = stp.getSignatureAppearance();
>
>
>
>         .
>
>           PdfSignature dic = new PdfSignature(validatorFilter,
> validSubFilter);
>
>           dic.setDate(new PdfDate(sap.getSignDate()));
>
>           dic.setName(signer.getCommonName()); // was:
> (PdfPKCS7.GetSubjectFields(chain[0]).GetField("CN"));
>
>           dic.setReason(reason);
>
>           dic.setLocation(sap.getLocation());
>
>           sap.setCryptoDictionary(dic);
>
>           HashMap exc = new HashMap();
>
>           exc.put(PdfName.CONTENTS, new Integer(contentEst * 2 + 2));
>
> //HERE           exc.put(PdfName.REASON, new Integer(reason.length()
> +
> 2));
>
>           sap.preClose(exc);
>
>         .
>
>           PdfPKCS7 sgn = new PdfPKCS7(key, chain, null, "SHA1", "BC",
> true); // true if subfilter adbe.pkcs7.sha1
>
>           InputStream is = sap.getRangeStream();
>
>         .
>
>           encodedTST = sgn.getEncodedPKCS7();
>
>           PdfDictionary dic2 = new PdfDictionary();
>
>           dic2.put(PdfName.CONTENTS, new
> PdfString(tstBytes).setHexWriting(true));
>
> //HERE           dic2.put(PdfName.REASON, new PdfString(reason)); //
> NOTE: no text change here
>
>           sap.close(dic2);
>
>
>
>
>
> The main difference in the generated PDF file is:
>
> /ByteRange [0 265 7427 4135 ]
>
> /ByteRange [0 227 256 10 7428 4135 ]
>
>
>
> The PDF specification says there may be multiple ranges.
>
>
>
>
>
>
>
>
>
>
>
> Martin Brunecky
> Software Architect
>
>
>
>
> <mailto:mbrunecky@(protected)
> AIM: mbrunecky
>
>
> tel:
> fax:


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