Don't swallow exceptions on validation

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1641025 13f79535-47bb-0310-9956-ffa450edef68

src/ooxml/java/org/apache/poi/poifs/crypt/dsig/SignatureInfo.java

@@ -217,7 +217,10 @@ public class SignatureInfo implements SignatureConfigurable {
         
         /**
          * @return true, when the xml signature is valid, false otherwise
+         * 
+         * @throws EncryptedDocumentException if the signature can't be extracted or if its malformed
          */
+        @SuppressWarnings("unchecked")
         public boolean validate() {
             KeyInfoKeySelector keySelector = new KeyInfoKeySelector();
             try {
@@ -259,8 +262,9 @@ public class SignatureInfo implements SignatureConfigurable {
                 
                 return valid;
             } catch (Exception e) {
-                LOG.log(POILogger.ERROR, "error in marshalling and validating the signature", e);
-                return false;
+                String s = "error in marshalling and validating the signature";
+                LOG.log(POILogger.ERROR, s, e);
+                throw new EncryptedDocumentException(s, e);
             }
         }
     }