Hide password for signing

git-svn-id: https://svn.apache.org/repos/asf/xmlgraphics/fop-pdf-images/trunk@1868863 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/build.xml b/build.xml
index 2c8b796..76c3ef1 100644
--- a/build.xml
+++ b/build.xml
@@ -487,7 +487,9 @@
     <checksum algorithm="sha-512" fileext=".sha512">
       <fileset refid="bundle-files"/>
     </checksum>
-    <input message="Passphrase for your default private key (attention: passphrase will be echoed in clear text on the display!)" addproperty="pwd"/>
+    <input message="Passphrase for your default private key" addproperty="pwd">
+      <handler classname="org.apache.tools.ant.input.SecureInputHandler" />
+    </input>
     <antcall target="sign-file">
       <param name="sign.archive" value="${build.dir}/${name}-${version}.jar"/>
       <param name="pwd" value="${pwd}"/>