1 files changed, 187 insertions, 0 deletions
diff --git a/src/main/java/at/knowcenter/wag/egov/egiz/pdf/AdobeSignatureHelper.java b/src/main/java/at/knowcenter/wag/egov/egiz/pdf/AdobeSignatureHelper.java
new file mode 100644
index 0000000..a391c15
--- /dev/null
+++ b/src/main/java/at/knowcenter/wag/egov/egiz/pdf/AdobeSignatureHelper.java
@@ -0,0 +1,187 @@
+package at.knowcenter.wag.egov.egiz.pdf;
+
+import java.util.HashMap;
+
+import javax.xml.datatype.DatatypeFactory;
+import javax.xml.datatype.XMLGregorianCalendar;
+
+import org.apache.log4j.Logger;
+
+import at.gv.egiz.pdfas.exceptions.ErrorCode;
+import at.gv.egiz.pdfas.framework.signator.SignatorInformation;
+import at.gv.egiz.pdfas.utils.OgnlUtil;
+import at.knowcenter.wag.egov.egiz.cfg.SettingsReader;
+import at.knowcenter.wag.egov.egiz.exceptions.PresentableException;
+import at.knowcenter.wag.egov.egiz.exceptions.SettingsException;
+import at.knowcenter.wag.egov.egiz.sig.SignatureObject;
+
+import com.lowagie.text.Rectangle;
+import com.lowagie.text.pdf.PdfDate;
+import com.lowagie.text.pdf.PdfDictionary;
+import com.lowagie.text.pdf.PdfName;
+import com.lowagie.text.pdf.PdfSignature;
+import com.lowagie.text.pdf.PdfSignatureAppearance;
+import com.lowagie.text.pdf.PdfStamper;
+import com.lowagie.text.pdf.PdfString;
+
+/**
+ * Helper class for creating adobe signature attributes.
+ * 
+ * @author dferbas
+ *
+ */
+public class AdobeSignatureHelper {
+   private static final String ADOBE_SIGN_FIELDNAME_KEY = "adobeSignFieldName";
+
+   private static final String ADOBE_SIG_ENABLED_KEY = "adobeSignEnabled";
+
+   private static Logger logger = Logger.getLogger(AdobeSignatureHelper.class);
+   
+   public static final String ADOBE_SIG_FILTER = "Adobe.PDF-AS";
+   
+   public static final String ADOBE_SIG_TEXT_KEY = "adobeSignText";
+
+   /**
+    * Writes Adobe-pdf signature entry with itext
+    * 
+    * @param stamper
+    * @param si
+    * @param so
+    * @param atp
+    * @throws PresentableException
+    */
+   public static void createAdobeSignatureField(PdfStamper stamper, SignatorInformation si,
+         SignatureObject so, ActualTablePos atp) throws PresentableException {
+
+      try {
+         logger.info("create adobe signature field");
+         PdfSignatureAppearance sap = stamper.getSignatureAppearance();
+
+         String fieldName = getAdobeFieldName(so.getSignatureTypeDefinition().getType());
+         // find field num
+         int nexSigNum = 1;
+         while (stamper.getAcroFields().getField(fieldName + nexSigNum) != null) {
+            nexSigNum++;
+         }
+
+         sap.setCrypto(null, null, null, null);
+         // supress overlay text for visible signatures
+         sap.setLayer2Text("");
+         sap.setLayer4Text("");
+
+         // the following line marks the sig block as adobe sig
+         // sap.setVisibleSignature(createRectangleFromTablePos(iui.actualTablePos),
+         // iui.actualTablePos.page, "PDF-AS-Signatur");
+         sap.setVisibleSignature(new Rectangle(0, 0, 0, 0), atp.page, fieldName + " #" + nexSigNum);
+         String subfilter = "unknown";
+         if (so != null && so.getKZ() != null) {
+            subfilter = so.getKZ().toString();
+         } else if (si != null) {
+            subfilter = si.getSignSignatureObject().kz;
+         }
+         PdfSignature sig = new PdfSignature(new PdfName(ADOBE_SIG_FILTER), new PdfName(subfilter));
+         // the following fields are not shown by the reader, because its is no
+         // Standard filter
+         // sig.setLocation("location is not visible");
+         // sig.setReason("reason is not visible");
+         // sig.setContact("contact is not visible");
+         // sig.setDate(new PdfDate());
+         if (si != null) {
+            XMLGregorianCalendar c = DatatypeFactory.newInstance().newXMLGregorianCalendar(
+                  si.getSignSignatureObject().date);
+            sig.setDate(new PdfDate(c.toGregorianCalendar()));
+         }
+         sig.setName(getAdobeSignText(so.getSignatureTypeDefinition().getType(), si));
+         sap.setCryptoDictionary(sig);
+
+         // content element is mandatory but empty
+         HashMap exc = new HashMap();
+         exc.put(PdfName.CONTENTS, new Integer(2));
+         sap.preClose(exc); // *2+2
+
+         PdfDictionary dic = new PdfDictionary();
+         dic.put(PdfName.CONTENTS, new PdfString((String) null).setHexWriting(true));
+         sap.close(dic);
+      } catch (Exception ex) {
+         logger.error("error", ex);
+         throw new PresentableException(ErrorCode.CANNOT_WRITE_PDF,
+               "Error creating adobe signature attribute", ex);
+      }
+   }
+   
+
+   /**
+    * Returns if adobe signature is enabled for the passed signature profile.
+    * Config key: {@value #ADOBE_SIG_ENABLED_KEY}
+    * @param sigProfile
+    * @return
+    */
+   public static boolean isAdobeSignatureFieldEnabled(String sigProfile) {
+      return "true".equalsIgnoreCase(
+            getDefaultableConfigProperty(sigProfile, ADOBE_SIG_ENABLED_KEY, "false"));
+   }
+
+   protected static Rectangle createRectangleFromTablePos(ActualTablePos pos) {
+      return new Rectangle(pos.x, pos.y, pos.x + pos.width, pos.y - pos.height);
+   }
+   
+   private static String getAdobeFieldName(String sigProfile) {
+      return getDefaultableConfigProperty(sigProfile, ADOBE_SIGN_FIELDNAME_KEY, "PDF-AS-Signatur");
+   }
+   
+   private static String getDefaultableConfigProperty(String sigProfile, String propName, String defaultValue) {      
+      String confVal;
+      try {
+         confVal = SettingsReader.getInstance().getSetting(
+               "sig_obj." + sigProfile + "." + propName,
+               "default." + propName,
+               defaultValue);
+      } catch (SettingsException e) {
+         logger.warn("error reading " + propName  + " from config. Using default: " + defaultValue, e);
+         return defaultValue;
+      }
+      return confVal;            
+   }
+
+   /**
+    * Evaluate name for adobe signature field. Get from config. Evaluate ognl if
+    * ok.
+    * 
+    * @param sigProfile
+    * @param si
+    * @return
+    */
+   private static String getAdobeSignText(String sigProfile, SignatorInformation si) {
+      String defaultName = "PDF-AS";
+      try {
+         logger.debug("reading adobe sig name for profile: " + sigProfile);
+         String propKey = ADOBE_SIG_TEXT_KEY + ".textual";
+         if (si == null) {
+            propKey = propKey.replaceAll("textual", "binary");
+         }
+         String adobeStr = getDefaultableConfigProperty(sigProfile, propKey, defaultName);
+       
+         HashMap ognlCtx = new HashMap();
+         OgnlUtil ognl = new OgnlUtil(ognlCtx);
+         if (ognl.containsExpression(adobeStr)) {
+            if (si == null) {
+               logger
+                     .error(ADOBE_SIG_TEXT_KEY
+                           + " ognl expressions not allowed for binary signatures (SignatorInformation not available)");
+               return defaultName;
+            }
+            ognlCtx.put("si", si);
+            ognlCtx.put("sso", si.getSignSignatureObject());
+            String res = ognl.compileMessage(adobeStr);
+            return res;
+         } else {
+            return adobeStr;
+         }
+
+      } catch (Exception ex) {
+         logger.warn("error creating adobe sign text, using default '" + defaultName + "'", ex);
+         return defaultName;
+      }
+   }
+
+}