Allow to sign SOAP attachments

See gh-107

spring-ws-security/src/main/java/org/springframework/ws/soap/security/wss4j2/Wss4jSecurityInterceptor.java

@@ -199,6 +199,8 @@ public class Wss4jSecurityInterceptor extends AbstractWsSecurityInterceptor impl
 
 	private CallbackHandler samlCallbackHandler;
 
+	private CallbackHandler attachmentCallbackHandler;
+
 	// Allow RSA 15 to maintain default behavior
 	private boolean allowRSA15KeyTransportAlgorithm = true;
 
@@ -458,6 +460,14 @@ public class Wss4jSecurityInterceptor extends AbstractWsSecurityInterceptor impl
 		this.samlCallbackHandler = samlCallbackHandler;
 	}
 
+	/**
+	 * Sets the attachment callback handler used for SwA signature/encryption
+     * @param attachmentCallbackHandler
+     */
+    public void setAttachmentCallbackHandler (CallbackHandler attachmentCallbackHandler) {
+        this.attachmentCallbackHandler = attachmentCallbackHandler;
+    }
+
 	/**
 	 * Sets the server-side time to live.
 	 */
@@ -705,6 +715,8 @@ public class Wss4jSecurityInterceptor extends AbstractWsSecurityInterceptor impl
 
 		requestData.setWssConfig(this.wssConfig);
 
+		requestData.setAttachmentCallbackHandler(attachmentCallbackHandler);
+
 		messageContext.setProperty(WSHandlerConstants.TTL_TIMESTAMP, Integer.toString(this.securementTimeToLive));
 
 		if (this.samlCallbackHandler != null) {