Detection of incremental updates updated.

Bug fixed. There was an error concerning empty HashInputData parsing a MOA CreateXMLSignatureResponse.
Demo source for API usage created.
Issue resolved: Prevent signature of empty document which leads to a meaningless error message from the bku.


git-svn-id: https://joinup.ec.europa.eu/svn/pdf-as/trunk@284 7b5415b0-85f9-ee4d-85bd-d5d0c3b42d1c

1 files changed, 81 insertions, 108 deletions

diff --git a/src/main/java/at/gv/egiz/pdfas/impl/vfilter/VerificationFilterImpl.java b/src/main/java/at/gv/egiz/pdfas/impl/vfilter/VerificationFilterImpl.java
index d353b9a..3ca497b 100644
--- a/src/main/java/at/gv/egiz/pdfas/impl/vfilter/VerificationFilterImpl.java
+++ b/src/main/java/at/gv/egiz/pdfas/impl/vfilter/VerificationFilterImpl.java
@@ -4,8 +4,10 @@
 package at.gv.egiz.pdfas.impl.vfilter;

 

 import java.util.ArrayList;

+import java.util.HashSet;

 import java.util.Iterator;

 import java.util.List;

+import java.util.Set;

 

 import org.apache.commons.lang.time.StopWatch;

 import org.apache.commons.logging.Log;

@@ -54,7 +56,6 @@ public class VerificationFilterImpl implements VerificationFilter
   private static final Log log = LogFactory.getLog(VerificationFilterImpl.class);

 

 

-  // tzefferer: added

   public static final String CHECK_DOCUMENT = "check_document";

   public static final String BINARY_ONLY = "binary_only";

   public static final String ASSUME_ONLY_SIGNATURE_BLOCKS = "assume_only_signature_blocks";

@@ -93,7 +94,7 @@ public class VerificationFilterImpl implements VerificationFilter
     }

     String check_doc = settings.getSetting(CHECK_DOCUMENT, "false");

 

-    // tzefferer: check document for textual sigs here here if binary_only is set    

+    // check document for textual sigs here here if binary_only is set    

     if ("true".equalsIgnoreCase(check_doc) &&

       parameters.extractBinarySignaturesOnly()) {

 

@@ -215,8 +216,8 @@ public class VerificationFilterImpl implements VerificationFilter
 

     if (linearization_index >= 0)

     {

-      // logger_.debug("The document is linearized - unrolling

-      // linearization block " + linearization_index);

+//       logger_.debug("The document is linearized - unrolling

+//       linearization block " + linearization_index);

       blocks.remove(linearization_index);

     }

   }

@@ -259,6 +260,19 @@ public class VerificationFilterImpl implements VerificationFilter
   {

     List binarySignatures = extractBinarySignaturesOnly(pdf, blocks);

 

+    // extract signature values of found binary signature blocks and store these values in a Set

+    // this set is later used to filter out the binary signatures that are recognized as text

+    // signatures.

+    Set binarySigValues = new HashSet();

+    Iterator iterator = binarySignatures.iterator();

+    while(iterator.hasNext()) {

+      

+      SignatureHolder sh = (SignatureHolder)iterator.next();

+      

+      String sigVal = sh.getSignatureObject().getSignationValue();

+      binarySigValues.add(sigVal);

+    }

+    

     SignatureHolder oldSignature = null;

     

     //List originalPartitions = partitions;

@@ -278,23 +292,35 @@ public class VerificationFilterImpl implements VerificationFilter
     }

     String check_doc = settings.getSetting(CHECK_DOCUMENT, "false");

     

-    // flags for determination of illegal incremental update

-    int sigsFound = 0; 

-    int sigsFoundPrev = 0;

+    // flag indicating that the last IU-block of the document is a non-signature IU-block

     boolean lastBlockWasModified = false;

     

+    // counter of all signatures (textual and binary) of this document

+    int signatureCounter = 0;

+    

+    // counter of all textual signatures in this document

+    int txtSigsSoFar = 0;

+    

+    // counter of all textual signatures in the current partition

+    int txtSigsThisPartition = 0;

+    

     List partitionResults = new ArrayList(partitions.size());

-    List nshList = new ArrayList();

+    List nshList = new ArrayList();    

+    

+    boolean sigFound = false;

     

     for (int i = 0; i < partitions.size(); i++)

     {

       Partition p = (Partition) partitions.get(i);

       

-

+      // updating flag and counter

+      boolean partitionContainsNewTextSignatures = true;

+      txtSigsSoFar = txtSigsThisPartition;

+      

       if (p instanceof TextPartition)

       {

         TextPartition tp = (TextPartition) p;

-

+        

         List partitionResult = null;

 

         boolean scanThisPartitionForOldSignature = (i == 0) && scanForOldSignatures;

@@ -309,27 +335,59 @@ public class VerificationFilterImpl implements VerificationFilter
           partitionResult = extractSignaturesFromPartition(pdf, tp);

         }

         

-        sigsFoundPrev = sigsFound;

-        sigsFound = partitionResult.size();

+        // binary signature blocks that have been detected as well are identified by comparing their signature values 

+        // with those stored in our Set above and are not considered for our IU-check

+        List onlyTextSignatures = new ArrayList();

+        Iterator iter = partitionResult.iterator();

+        while(iter.hasNext()) {

+          

+          SignatureHolder sh = (SignatureHolder)iter.next();

+          if(!binarySigValues.contains(sh.getSignatureObject().getSignationValue())) {

+            

+            onlyTextSignatures.add(sh);

+          }

+        }

+        

+        // update signature counters

+        txtSigsThisPartition = onlyTextSignatures.size();

+        int newTextSignatures = txtSigsThisPartition - txtSigsSoFar;

+        signatureCounter = signatureCounter + newTextSignatures;

+        

+        // update sigFound flag

+        if(txtSigsThisPartition > 0) {

+          

+          sigFound = true;

+        }

+        

+        // TextPartition is only valid, if at least one more text signature has been found than in the previous text partition

+        if(!(newTextSignatures > 0)) {

+          

+          partitionContainsNewTextSignatures = false;

+        }

+

         partitionResults.add(partitionResult);

       } else {

         // should be binary partition

         if(p instanceof BinaryPartition) {

+          

           BinaryPartition binpart = (BinaryPartition)p;

-          // add number (n) of found binary signatures - if there is a subsequent textual partition, 

-          // at least n+1 sigs have to be found (note: sig-blocks of binary signatures are also extracted and detected) 

-          sigsFound = sigsFound + binpart.blocks.size();

+

+          // updating counter and flag

+          signatureCounter = signatureCounter + binpart.blocks.size();

+          sigFound = true;

           

         }

       }

       

-      // add NoSignatureHolder object if there were already signatures, but current block does not contain any signatures

-      if((check_doc.equalsIgnoreCase("true"))&& ((sigsFoundPrev > 0) && !(sigsFound > sigsFoundPrev)) ) {

-        

-        nshList.add(new NoSignatureHolder(sigsFound));                

-        

+      // if document checking is enabled, at least one signature has been found so far, we are dealing with a

+      // non-signature IU-block

+      if((check_doc.equalsIgnoreCase("true"))&& (sigFound && !partitionContainsNewTextSignatures))  {

+              

+        nshList.add(new NoSignatureHolder(signatureCounter));        

         lastBlockWasModified = true;

+      

       } else {

+      

         lastBlockWasModified = false;

       }

       

@@ -669,10 +727,10 @@ public class VerificationFilterImpl implements VerificationFilter
     {

       int endOfDocument = VerificationFilterHelper.getEndOfPartition(partition);

 

-       log.debug("Extracting text from 0 to " + endOfDocument + " (total document size = " + pdf.getLength() + "):");

+//       log.debug("Extracting text from 0 to " + endOfDocument + " (total document size = " + pdf.getLength() + "):");

       String extractedText = extractText(pdf, endOfDocument);

-      log.debug("Extracting text finished.");

-      log.debug("extracted text: " + extractedText);

+//      log.debug("Extracting text finished.");

+//      log.debug("extracted text: " + extractedText);

 

       SignaturesAndOld sao = extractSignaturesAndOld(extractedText);

 

@@ -684,91 +742,6 @@ public class VerificationFilterImpl implements VerificationFilter
     }

   }

 

-//  // tzefferer: added method

-//  protected void checkDocument(PdfDataSource pdf, List blocks, VerificationFilterParameters parameters) throws VerificationFilterException {

-//    

-//    boolean consider_old_sigs = parameters.scanForOldSignatures();

-//    boolean binary_only = parameters.extractBinarySignaturesOnly();

-//    boolean assume_sigs_only = parameters.assumeOnlySignatureUpdateBlocks();

-//   

-//    if(binary_only) {

-//      // check if document contains textual signatures

-//      checkBinaryOnly(pdf, consider_old_sigs);

-//    }    

-//    if(!assume_sigs_only) {

-//      // check if document contains post-sign modifications

-//      checkUpdateBlocks(pdf, blocks, consider_old_sigs);

-//    }     

-//  }  

-  // tzefferer: added method

-//  protected void checkUpdateBlocks(PdfDataSource pdf, List blocks, boolean considerOldSigs) throws VerificationFilterException {

-//    

-//    boolean sig_detected = false;

-//    

-//    if (considerOldSigs) {

-//      

-//      DelimitedPdfDataSource dds = new DelimitedPdfDataSource(pdf, pdf.getLength());

-//      String text = null;

-//      try {

-//        text = PdfAS.extractNormalizedTextTextual(dds);

-//      } catch (PresentableException e) {

-//        throw new VerificationFilterException(e);

-//      }

-//      

-//      SignaturesAndOld sao = extractSignaturesAndOld(text);

-//      

-//      if ((sao != null) && (sao.oldSignature != null)) {

-//        sig_detected = true;

-//      }      

-//    }

-//    

-//    

-//    Iterator it = blocks.iterator();

-//    String prev_text = null;

-//

-//    while (it.hasNext())

-//    {

-//      boolean sig_in_current_block = false;

-//      

-//      FooterParseResult fpr = (FooterParseResult) it.next();

-//             

-//      DelimitedPdfDataSource dds = new DelimitedPdfDataSource(pdf, fpr.next_index);

-//     

-//      String text;

-//      try {

-//        text = PdfAS.extractNormalizedTextTextual(dds);

-//      } catch (PresentableException e) {

-//        throw new VerificationFilterException(e);

-//      }

-//

-//      if (prev_text == null) {

-//        prev_text = text;

-//      } else {

-//        String texttmp = text.substring(prev_text.length());

-//        prev_text = text;

-//        text = texttmp;

-//      }

-//

-//      List sig_holders = null;

-//      try {

-//        sig_holders = AbsoluteTextSignature.extractSignatureHoldersFromText(text);

-//      } catch (SignatureException e) {

-//        throw new VerificationFilterException(e);

-//      } catch (SignatureTypesException e) {

-//        throw new VerificationFilterException(e);

-//      }

-//      

-//      if((sig_holders != null) && (sig_holders.size() > 0)) {

-//        sig_detected = true;

-//        sig_in_current_block = true;

-//      }

-//

-//      if((sig_detected) && (!sig_in_current_block)) {

-//        throw new VerificationFilterException(ErrorCode.MODIFIED_AFTER_SIGNATION, "The document has been modified after being signed.");

-//      }       

-//    }            

-//  }

-  // tzefferer: added method

   protected void checkBinaryOnly(PdfDataSource pdf, boolean considerOldSigs) throws VerificationFilterException {

     

     DelimitedPdfDataSource dds = new DelimitedPdfDataSource(pdf, pdf.getLength());