adobe signature field helper

git-svn-id: https://joinup.ec.europa.eu/svn/pdf-as/trunk@493 7b5415b0-85f9-ee4d-85bd-d5d0c3b42d1c

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;

+      }

+   }

+

+}