/**
* Signs a PDF where space was already reserved.
* @param reader the original PDF
* @param fieldName the field to sign. It must be the last field
* @param outs the output PDF
* @param externalSignatureContainer the signature container doing the actual signing. Only the
* method ExternalSignatureContainer.sign is used
* @throws DocumentException
* @throws IOException
* @throws GeneralSecurityException
*/
public static void SignDeferred(PdfReader reader, String fieldName, Stream outs, IExternalSignatureContainer externalSignatureContainer) {
AcroFields af = reader.AcroFields;
PdfDictionary v = af.GetSignatureDictionary(fieldName);
if (v == null)
throw new DocumentException("No field");
if (!af.SignatureCoversWholeDocument(fieldName))
throw new DocumentException("Not the last signature");
PdfArray b = v.GetAsArray(PdfName.BYTERANGE);
long[] gaps = b.AsLongArray();
if (b.Size != 4 || gaps[0] != 0)
throw new DocumentException("Single exclusion space supported");
IRandomAccessSource readerSource = reader.SafeFile.CreateSourceView();
Stream rg = new RASInputStream(new RandomAccessSourceFactory().CreateRanged(readerSource, gaps));
byte[] signedContent = externalSignatureContainer.Sign(rg);
int spaceAvailable = (int)(gaps[2] - gaps[1]) - 2;
if ((spaceAvailable & 1) != 0)
throw new DocumentException("Gap is not a multiple of 2");
spaceAvailable /= 2;
if (spaceAvailable < signedContent.Length)
throw new DocumentException("Not enough space");
StreamUtil.CopyBytes(readerSource, 0, gaps[1] + 1, outs);
ByteBuffer bb = new ByteBuffer(spaceAvailable * 2);
foreach (byte bi in signedContent) {
bb.AppendHex(bi);
}
int remain = (spaceAvailable - signedContent.Length) * 2;
for (int k = 0; k < remain; ++k) {
bb.Append((byte)48);
}
bb.WriteTo(outs);
StreamUtil.CopyBytes(readerSource, gaps[2] - 1, gaps[3] + 1, outs);
}
/**
* Converts an annotation structure item to a Form XObject annotation.
* @param item the structure item
* @throws IOException
*/
virtual protected void ConvertToXObject(StructureObject item) {
PdfDictionary structElem = item.GetStructElem();
if (structElem == null)
return;
PdfDictionary dict = item.GetObjAsDict();
if (dict == null || !dict.CheckType(PdfName.ANNOT))
return;
PdfDictionary ap = dict.GetAsDict(PdfName.AP);
if (ap == null)
return;
PdfNumber structParent = dict.GetAsNumber(PdfName.STRUCTPARENT);
if (structParent == null)
return;
PdfStream stream = ap.GetAsStream(PdfName.N);
if (stream == null)
return;
stream.Put(PdfName.STRUCTPARENT, structParent);
PdfIndirectReference xobjr = ap.GetAsIndirectObject(PdfName.N);
if (xobjr == null)
return;
// remove the annotation from the page
for (int i = 0; i < annots.Length; i++) {
PdfIndirectReference annotref = annots.GetAsIndirectObject(i);
if (item.GetObjRef().Number == annotref.Number) {
annots.Remove(i);
break;
}
}
// replace the existing attributes by a PrintField attribute
PdfDictionary attribute = new PdfDictionary();
attribute.Put(PdfName.O, PdfName.PRINTFIELD);
PdfString description = dict.GetAsString(PdfName.TU);
if (description == null)
description = dict.GetAsString(PdfName.T);
if (PdfName.BTN.Equals(dict.Get(PdfName.FT))) {
PdfNumber fflags = dict.GetAsNumber(PdfName.FF);
if (fflags != null) {
int ff = fflags.IntValue;
if ((ff & PdfFormField.FF_PUSHBUTTON) != 0)
attribute.Put(PdfName.ROLE, PdfName.PB);
// I don't think the condition below will ever be true
if ((ff & PdfFormField.FF_RADIO) != 0)
attribute.Put(PdfName.ROLE, PdfName.rb);
else
attribute.Put(PdfName.ROLE, PdfName.CB);
}
}
else {
attribute.Put(PdfName.ROLE, PdfName.TV);
}
attribute.Put(PdfName.DESC, description);
// Updating the values of the StructElem dictionary
PdfString t = structElem.GetAsString(PdfName.T);
if (t == null || t.ToString().Trim().Length == 0)
structElem.Put(PdfName.T, dict.GetAsString(PdfName.T));
structElem.Put(PdfName.A, attribute);
structElem.Put(PdfName.S, PdfName.P);
structElem.Put(PdfName.PG, pageref);
// Defining a new MCID
int mcid = items.ProcessMCID(structParents, item.GetRef());
LOGGER.Info("Using MCID " + mcid);
structElem.Put(PdfName.K, new PdfNumber(mcid));
// removing the annotation from the parent tree
items.RemoveFromParentTree(structParent);
// Adding the XObject to the page
PdfName xobj = new PdfName("XObj" + structParent.IntValue);
LOGGER.Info("Creating XObject with name " + xobj);
xobjects.Put(xobj, xobjr);
PdfArray array = dict.GetAsArray(PdfName.RECT);
// Getting the position of the annotation
Rectangle rect = new Rectangle(
array.GetAsNumber(0).FloatValue, array.GetAsNumber(1).FloatValue,
array.GetAsNumber(2).FloatValue, array.GetAsNumber(3).FloatValue);
rect.Normalize();
// A Do operator is forbidden inside a text block
if (inText && !btWrite) {
LOGGER.Debug("Introducing extra ET");
byte[] bytes = Encoding.ASCII.GetBytes("ET\n");
baos.Write(bytes, 0, bytes.Length);
etExtra = true;
}
// Writing the marked-content sequence with the Do operator
// Note that the position assumes that the CTM wasn't changed in the graphics state
// TODO: do the math if the CTM did change!
ByteBuffer buf = new ByteBuffer();
buf.Append("/P <</MCID ");
buf.Append(mcid);
buf.Append(">> BDC\n");
buf.Append("q 1 0 0 1 ");
buf.Append(rect.Left.ToString(CultureInfo.InvariantCulture));
buf.Append(" ");
buf.Append(rect.Bottom.ToString(CultureInfo.InvariantCulture));
buf.Append(" cm ");
buf.Append(xobj.GetBytes());
buf.Append(" Do Q\n");
buf.Append("EMC\n");
buf.Flush();
buf.WriteTo(baos);
// if we were inside a text block, we've introduced an ET, so we'll need to write a BT
if (inText)
btWrite = true;
}