Config-parameter "check_document" introduced.

git-svn-id: https://joinup.ec.europa.eu/svn/pdf-as/trunk@224 7b5415b0-85f9-ee4d-85bd-d5d0c3b42d1c

2 files changed, 162 insertions, 3 deletions

diff --git a/src/main/java/at/gv/egiz/pdfas/exceptions/ErrorCode.java b/src/main/java/at/gv/egiz/pdfas/exceptions/ErrorCode.java
index 332974b..dcb5f30 100644
--- a/src/main/java/at/gv/egiz/pdfas/exceptions/ErrorCode.java
+++ b/src/main/java/at/gv/egiz/pdfas/exceptions/ErrorCode.java
@@ -36,6 +36,9 @@ public final class ErrorCode
   

   public static final int CERTIFICATE_NOT_FOUND = 313;

   public static final int NOT_SEMANTICALLY_EQUAL = 314;

+

+  public static final int MODIFIED_AFTER_SIGNATION = 316;

+  public static final int NON_BINARY_SIGNATURES_PRESENT = 317;  

   

   public static final int WEB_EXCEPTION = 330;

 

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 0c9e1f2..3fe17bf 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
@@ -10,6 +10,7 @@ import java.util.List;
 import org.apache.commons.logging.Log;

 import org.apache.commons.logging.LogFactory;

 

+import at.gv.egiz.pdfas.exceptions.ErrorCode;

 import at.gv.egiz.pdfas.exceptions.framework.VerificationFilterException;

 import at.gv.egiz.pdfas.framework.SignatureHolderHelper;

 import at.gv.egiz.pdfas.framework.VerificatorFactory;

@@ -26,9 +27,11 @@ import at.gv.egiz.pdfas.impl.vfilter.partition.BinaryPartition;
 import at.gv.egiz.pdfas.impl.vfilter.partition.TextPartition;

 import at.knowcenter.wag.egov.egiz.PdfAS;

 import at.knowcenter.wag.egov.egiz.PdfASID;

+import at.knowcenter.wag.egov.egiz.cfg.SettingsReader;

 import at.knowcenter.wag.egov.egiz.exceptions.NormalizeException;

 import at.knowcenter.wag.egov.egiz.exceptions.PDFDocumentException;

 import at.knowcenter.wag.egov.egiz.exceptions.PresentableException;

+import at.knowcenter.wag.egov.egiz.exceptions.SettingsException;

 import at.knowcenter.wag.egov.egiz.exceptions.SignatureException;

 import at.knowcenter.wag.egov.egiz.exceptions.SignatureTypesException;

 import at.knowcenter.wag.egov.egiz.pdf.AbsoluteTextSignature;

@@ -48,6 +51,10 @@ public class VerificationFilterImpl implements VerificationFilter
    */

   private static final Log log = LogFactory.getLog(VerificationFilterImpl.class);

 

+

+  // tzefferer: added

+  public static final String CHECK_DOCUMENT = "check_document";

+  

   /**

    * @see at.gv.egiz.pdfas.framework.vfilter.VerificationFilter#extractSignatureHolders(at.gv.egiz.pdfas.framework.input.PdfDataSource,

    *      java.util.List,

@@ -62,9 +69,23 @@ public class VerificationFilterImpl implements VerificationFilter
       log.debug("Original IU blocks: " + blocks.size());

       debugIUBlocks(blocks);

     }

-

+    

     unrollLinearization(blocks);

 

+  // tzefferer: check document here

+    SettingsReader settings;

+    try {

+      settings = SettingsReader.getInstance();

+    } catch (SettingsException e) {

+      throw new VerificationFilterException(e);

+    }

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

+   

+    if(check_doc.equalsIgnoreCase("true")) {

+      checkDocument(pdf, blocks, parameters);

+    }

+    // end add

+    

     if (log.isDebugEnabled())

     {

       log.debug("IU blocks without linearization: " + blocks.size());

@@ -192,8 +213,10 @@ public class VerificationFilterImpl implements VerificationFilter
 

   protected List performSemiConservative(PdfDataSource pdf, boolean scanForOldSignatures, List blocks, List partitions) throws VerificationFilterException

   {

+    log.debug("perform semiConservative()...");

     List binarySignatures = extractBinarySignaturesOnly(pdf, blocks);

 

+    log.debug("determining last partition...");

     TextPartition lastTextPartition = VerificationFilterHelper.findLastTextPartition(partitions);

     List extractedSignatures = null;

     if (scanForOldSignatures)

@@ -207,9 +230,11 @@ public class VerificationFilterImpl implements VerificationFilter
     }

     else

     {

+      log.debug("extracting signatures from last partition...");

       extractedSignatures = extractSignaturesFromPartition(pdf, lastTextPartition);

     }

-

+    

+    

     List signatureHolderChain = intermingleSignatures(binarySignatures, extractedSignatures);

 

     return signatureHolderChain;

@@ -284,12 +309,16 @@ public class VerificationFilterImpl implements VerificationFilter
   }

 

   protected String extractText(PdfDataSource pdf, int endOfDocument) throws PresentableException

+

   {

+    log.debug("EXTRACTING TEXT... end index = " + endOfDocument);

+    

     DelimitedPdfDataSource dds = new DelimitedPdfDataSource(pdf, endOfDocument);

     //DelimitedInputStream dis = new DelimitedInputStream(pdf.createInputStream(), endOfDocument);

     return PdfAS.extractNormalizedTextTextual(dds);

   }

-

+  

+  

   protected List extractNewSignaturesFromText(String text) throws VerificationFilterException

   {

     try

@@ -450,10 +479,12 @@ public class VerificationFilterImpl implements VerificationFilter
       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 signatures:");

       List extractedSignatures = extractNewSignaturesFromText(extractedText);

       log.debug("Extracting signatures finished.");

+      log.debug("Number of found signatures: " + extractedSignatures.size());

       

       if (log.isDebugEnabled())

       {

@@ -519,6 +550,130 @@ 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());

+    String text = null;

+    try {

+      text = PdfAS.extractNormalizedTextTextual(dds);

+    } catch (PresentableException e) {

+      throw new VerificationFilterException(e);

+    }

+    

+    List sigs = new ArrayList();

+        

+    if(considerOldSigs) {            

+      SignaturesAndOld sao = extractSignaturesAndOld(text);

+      if(sao != null) {

+        if(sao.newSignatures != null) {

+          sigs.addAll(sao.newSignatures);

+        }

+        if(sao.oldSignature != null) {

+          sigs.add(sao.oldSignature);

+        }

+      }

+    } else {   

+      List signatures = extractSignatures(pdf, pdf.getLength());

+      if(signatures != null) {

+        sigs.addAll(signatures);

+      }

+    }

+    

+    Iterator it = sigs.iterator();

+    while(it.hasNext()) {

+      SignatureHolder current = (SignatureHolder)it.next();

+      if((current != null)&&(!current.getSignatureObject().isBinary())) {

+        throw new VerificationFilterException(ErrorCode.NON_BINARY_SIGNATURES_PRESENT, "The document contains non-binary signatures.");

+      }

+    }    

+  }

+  

+  

   protected static class SignaturesAndOld

   {

     public List newSignatures = null;

@@ -537,6 +692,7 @@ public class VerificationFilterImpl implements VerificationFilter
       log.debug("Extracting old signatures:");

       SignatureHolder oldSignature = extractOldSignature(text, extractedSignatures);

       log.debug("Extracting old signatures finished.");

+      log.debug("oldSignature = null: " + (oldSignature==null));

 

       SignaturesAndOld sao = new SignaturesAndOld();

       sao.newSignatures = extractedSignatures;