1 files changed, 13 insertions, 6 deletions
diff --git a/pdf-as-lib/src/main/java/at/gv/egiz/pdfas/impl/vfilter/helper/VerificationFilterBinaryHelper.java b/pdf-as-lib/src/main/java/at/gv/egiz/pdfas/impl/vfilter/helper/VerificationFilterBinaryHelper.java
index 735b874..3093c36 100644
--- a/pdf-as-lib/src/main/java/at/gv/egiz/pdfas/impl/vfilter/helper/VerificationFilterBinaryHelper.java
+++ b/pdf-as-lib/src/main/java/at/gv/egiz/pdfas/impl/vfilter/helper/VerificationFilterBinaryHelper.java
@@ -48,7 +48,7 @@ import at.knowcenter.wag.exactparser.parsing.results.ObjectParseResult;
 
 /**
  * Contains helpful methods used by the VerificationFilter to analyze the PDF for binary signatures.
- * 
+ *
  * @author wprinz
  */
 public final class VerificationFilterBinaryHelper
@@ -70,12 +70,12 @@ public final class VerificationFilterBinaryHelper
 
   /**
    * Tells, if the given incremental update block contains a binary signature.
-   * 
+   *
    * <p>
    * According to definition, if a block is a binary block, it must/cannot
    * contain other signatures than this one.
    * </p>
-   * 
+   *
    * @param block
    *          The incremental update block.
    * @return Returns true, if this block is a binary signature block, false
@@ -94,7 +94,7 @@ public final class VerificationFilterBinaryHelper
 
   /**
    * Extracts the PDF AS ID of the egiz block.
-   * 
+   *
    * @param pdf
    *          The pdf.
    * @param block
@@ -120,6 +120,13 @@ public final class VerificationFilterBinaryHelper
     IndirectObjectReference ior = egiz_dict_iorpr.ior;
 
     final int egiz_dict_offset = PDFUtils.getObjectOffsetFromXRefByIndirectObjectReference(block.xpr, ior);
+
+	// fix dti:
+	if (egiz_dict_offset < 0) {
+		log.debug("Current ui block contains a /EGIZSigDict trailer entry but no respective xref table entry. This indicates that this ui block does not contain binary signatures.");
+		return null;
+	}
+
     // logger_.debug("egiz_dict_offset = " + egiz_dict_offset);
 
     ObjectParseResult obj = PDFUtils.parseObject(pdf, egiz_dict_offset);
@@ -140,7 +147,7 @@ public final class VerificationFilterBinaryHelper
 
   /**
    * Restores the Kennzeichnung String from an Array.
-   * 
+   *
    * @param pdf
    *          The PDF.
    * @param kz_apr
@@ -174,7 +181,7 @@ public final class VerificationFilterBinaryHelper
         si.pdf = pdf;
 
         log.trace("Adding KZ: " + si.toString());
-        
+
         partition.add(si);
       }