/**
* Reads input file to get PDFObjects from the original PDF
*
*/
public Dictionary <object, object> ReadinputFile(PDFDocument pdfDoc)
{
PDFImportedPage ip;
Dictionary <Object, Object> PlainDictionary = new Dictionary <Object, Object>();
PDFObjectsProcessor objectsProcessor = new PDFObjectsProcessor();
for (int PageIndex = 0; PageIndex < pdfDoc.Pages.Count; PageIndex++)
{
ip = (PDFImportedPage)pdfDoc.Pages[PageIndex];
PDFPageObjectCollection Objects = ip.ExtractPageObjects();
//SHA256 mySHA256 = SHA256Managed.Create();
//string content = ip.ExtractText();
//byte[] hashedContentKey = mySHA256.ComputeHash(GenerateStreamFromString(content));
List <Words> WordObjects = new List <Words>();
List <Blocks> BlockList = new List <Blocks>();
for (int j = 0; j < Objects.Count; j++)
{
if (Objects[j] is PDFTextPageObject)
{
PDFTextPageObject TextObject = (PDFTextPageObject)Objects[j];
WordObjects = objectsProcessor.GetWords(TextObject, WordObjects);
//BlockList = objectsProcessor.GetBlocks(TextObject, BlockList);
}
else if (Objects[j] is PDFImagePageObject)
{
_imageObjects.Add((PDFImagePageObject)Objects[j]);
}
else if (Objects[j] is PDFPathPageObject)
{
_pathObjects.Add((PDFPathPageObject)Objects[j]);
}
}
//PlainDictionary.Add(PageIndex, BlockList);
PlainDictionary.Add(PageIndex, WordObjects);
}
pdfDoc.Dispose();
return(PlainDictionary);
}
/**
* Processes PDFObjects and returns blocks
*
*/
public List <Blocks> GetBlocks(PDFTextPageObject TextObject, List <Blocks> BlockList)
{
Blocks block;
bool firstCharacter;
FontsProcessor fontsProcessor = new FontsProcessor();
PDFGlyphCollection GlyphCollection = TextObject.Glyphs;
if (BlockList.Count == 0 || BlockList[BlockList.Count - 1].BlockComplete)
{
firstCharacter = true;
block = new Blocks();
}
else
{
firstCharacter = false;
block = BlockList[BlockList.Count - 1];
BlockList.RemoveAt(BlockList.Count - 1);
}
for (int i = 0; i < GlyphCollection.Count; i++)
{
block.Block = block.Block + GlyphCollection[i].Text;
if (block.Block.Length == 16)
{
block.BlockComplete = true;
BlockList.Add(block);
if (++i >= GlyphCollection.Count)
{
return(BlockList);
}
firstCharacter = true;
block = new Blocks();
block.Block = block.Block + GlyphCollection[i].Text;
}
if (firstCharacter)
{
firstCharacter = false;
block.FontBase = fontsProcessor.GetFontBase(TextObject.FontName, TextObject.FontSize);
block.FontBrush = new PDFBrush(TextObject.FillColor);
block.Top.Add(GlyphCollection[i].DisplayBounds.Top);
block.Left.Add(GlyphCollection[i].DisplayBounds.Left);
}
else
{
if (GlyphCollection[i].DisplayBounds.Top > block.TopOfLastCharacter)
{
block.Chunks.Add(block.Block.Length - 1);
block.Top.Add(GlyphCollection[i].DisplayBounds.Top);
block.Left.Add(GlyphCollection[i].DisplayBounds.Left);
}
}
block.TopOfLastCharacter = GlyphCollection[i].DisplayBounds.Top;
}
BlockList.Add(block);
return(BlockList);
}
/**
* Iterates through encrypted documents and encrypted keywords to check if provided keyword exists or not
*
*
*/
public void SearchKeyWord()
{
List <PDFDocument> documentsList;
foreach (KeyValuePair <string, List <PDFDocument> > document in _encryptedDocuments)
{
Stopwatch watch = new Stopwatch();
watch.Start();
documentsList = document.Value;
List <string[]> coefficientList = RetrieveCoefficients(documentsList);
List <int> decryptedCoef = new CoefficientCodec(0, _numOfShares, _shareforRec, "Decrypt", coefficientList).coefficients;
List <int> CoefNeededToSearch = PerformCombinationOfCoef(decryptedCoef, _shareforRec - 1);
PDFDocument docShare = documentsList[0];
bool keywordFound = false;
Console.WriteLine("CoefNeededToSearch : " + CoefNeededToSearch.Count);
for (int coefIndex = 0; coefIndex < CoefNeededToSearch.Count; coefIndex++)
{
Share[] share = ShareGenerator.GenerateShares(_keyword, _numOfShares, _shareforRec, new int[] { CoefNeededToSearch[coefIndex] }, new SortedDictionary <int, int>());
for (int pageIndex = 0; pageIndex < docShare.Pages.Count; pageIndex++)
{
PDFPage page = docShare.Pages[pageIndex];
string text = ((PDFImportedPage)page).ExtractText();
PDFImportedPage ip = (PDFImportedPage)docShare.Pages[pageIndex];
PDFPageObjectCollection Objects = ip.ExtractPageObjects();
for (int j = 0; j < Objects.Count; j++)
{
if (Objects[j] is PDFTextPageObject)
{
PDFTextPageObject TextObject = (PDFTextPageObject)Objects[j];
if (TextObject.Text == share[0].GetCipherText())
{
keywordFound = true;
}
}
}
}
}
if (keywordFound)
{
watch.Stop();
Console.WriteLine("Search Time : " + watch.ElapsedMilliseconds);
watch.Reset();
watch.Start();
ShareAssemblerController shareAssembler = new ShareAssemblerController(_numOfShares, _shareforRec, _keyword);
shareAssembler.SharesReconstructor();
keywordFound = true;
watch.Stop();
Console.WriteLine("Decrypt and Highlight Time : " + watch.ElapsedMilliseconds);
}
else
{
Console.WriteLine("NO FILES CONTAIN THE KEYWORD YOU'RE LOOKING FOR.");
}
}
}
/**
* Processes PDFObjects and returns words
*
*/
public List <Words> GetWords(PDFTextPageObject TextObject, List <Words> WordObjects)
{
Words Word;
bool firstCharacter;
FontsProcessor fontsProcessor = new FontsProcessor();
PDFGlyphCollection GlyphCollection = TextObject.Glyphs;
if (WordObjects.Count == 0 || WordObjects[WordObjects.Count - 1].WordComplete)
{
firstCharacter = true;
Word = new Words();
}
else
{
firstCharacter = false;
Word = WordObjects[WordObjects.Count - 1];
Word.Added = false;
WordObjects.RemoveAt(WordObjects.Count - 1);
}
for (int i = 0; i < GlyphCollection.Count; i++)
{
if (String.IsNullOrWhiteSpace(GlyphCollection[i].Text))
{
firstCharacter = true;
if (!String.IsNullOrEmpty(Word.Word))
{
Word.WordComplete = true;
if (!Word.Added)
{
Word.Added = true;
WordObjects.Add(Word);
}
Word = new Words();
}
}
else
{
Word.Word = Word.Word + GlyphCollection[i].Text;
if (firstCharacter)
{
firstCharacter = false;
Word.FontBase = fontsProcessor.GetFontBase(TextObject.FontName, TextObject.FontSize);
Word.FontBrush = new PDFBrush(TextObject.FillColor);
Word.Top = GlyphCollection[i].DisplayBounds.Top;
Word.Left = GlyphCollection[i].DisplayBounds.Left;
}
}
}
if (Word.Word != "")
{
Word.Added = true;
WordObjects.Add(Word);
}
return(WordObjects);
}
/**
* Recontructs the encrypted shares of the PDF to get original PDF.
* Hightlights every occurrences of the word that a user has searched for.
*
*/
public void SharesReconstructor()
{
List <List <PDFPageObjectCollection> > pDFPageObjects = ExtractObjects();
List <PDFPageObjectCollection> ObjectsPerPage;
PDFBrush redBrush = new PDFBrush(new PDFRgbColor(204, 255, 51));
PDFPen pen = new PDFPen(new PDFRgbColor(204, 255, 51), 1);
string[] shares;
for (int pageIndex = 0; pageIndex < pDFPageObjects.Count; pageIndex++)
{
_decryptedPDF.AddPage();
ObjectsPerPage = pDFPageObjects[pageIndex];
for (int wordIndex = 0; wordIndex < ObjectsPerPage[0].Count; wordIndex++)
{
shares = new string[_shareforRec];
PDFTextPageObject TextObject = null;
FontsProcessor fontsProcessor = null;
bool shouldProcess = false;
for (int shareIndex = 0; shareIndex < _shareforRec; shareIndex++)
{
PDFPageObjectCollection collection = ObjectsPerPage[shareIndex];
if (collection[wordIndex] is PDFTextPageObject)
{
TextObject = (PDFTextPageObject)collection[wordIndex];
if (TextObject.Text == "PDF4NET evaluation version 5.0.1.0")
{
shouldProcess = false;
break;
}
shares[shareIndex] = TextObject.Text;
fontsProcessor = new FontsProcessor();
shouldProcess = true;
}
}
if (shouldProcess)
{
string decryptedText = ShareAssembler.TextReconstruction(shares, _shareNumbers, _numOfShares, _shareforRec);
PDFBrush brush = new PDFBrush(TextObject.FillColor);
PDFFontBase FontBase = fontsProcessor.GetFontBase(TextObject.FontName, TextObject.FontSize);
if (decryptedText.ToLower().Equals(_keyword.ToLower()))
{
_decryptedPDF.Pages[pageIndex].Canvas.DrawRectangle(pen, redBrush, TextObject.DisplayBounds.Left, TextObject.DisplayBounds.Top, 4 * decryptedText.Length, FontBase.Size, 0);
for (int i = 0; i < _encryptedPdf.Count; i++)
{
_encryptedPdf[i].Pages[pageIndex].Canvas.DrawRectangle(pen, redBrush, TextObject.DisplayBounds.Left, TextObject.DisplayBounds.Top, 4 * decryptedText.Length, FontBase.Size, 0);
_encryptedPdf[i].Pages[pageIndex].Canvas.DrawText(shares[i > shares.Length - 1 ? 0 : i], FontBase, brush, TextObject.DisplayBounds.Left, TextObject.DisplayBounds.Top);
}
}
_decryptedPDF.Pages[pageIndex].Canvas.DrawText(decryptedText, FontBase, brush, TextObject.DisplayBounds.Left, TextObject.DisplayBounds.Top);
}
}
}
for (int i = 0; i < _encryptedPdf.Count; i++)
{
_encryptedPdf[i].Save(_encryptedFilePath + (i + 1) + ".pdf");
}
_decryptedPDF.Save(_decryptedFilePath);
}
