package org.springframework.security.web.header.writers.frameoptions;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.util.Assert;
import org.springframework.util.StringUtils;

import javax.servlet.http.HttpServletRequest;

/**
 * Base class for AllowFromStrategy implementations which use a request parameter to retrieve the origin. By default
 * the parameter named <code>x-frames-allow-from</code> is read from the request.
 *
 * @author Marten Deinum
 * @since 3.2
 */
abstract class AbstractRequestParameterAllowFromStrategy implements AllowFromStrategy {

    private static final String DEFAULT_ORIGIN_REQUEST_PARAMETER = "x-frames-allow-from";

    private String allowFromParameterName = DEFAULT_ORIGIN_REQUEST_PARAMETER;

    /** Logger for use by subclasses */
    protected final Log log = LogFactory.getLog(getClass());


    public String getAllowFromValue(HttpServletRequest request) {
        String allowFromOrigin = request.getParameter(allowFromParameterName);
        if (log.isDebugEnabled()) {
            log.debug("Supplied origin '"+allowFromOrigin+"'");
        }
        if (StringUtils.hasText(allowFromOrigin) && allowed(allowFromOrigin)) {
            return "ALLOW-FROM " + allowFromOrigin;
        } else {
            return "DENY";
        }
    }

    /**
     * Sets the HTTP parameter used to retrieve the value for the origin that is
     * allowed from. The value of the parameter should be a valid URL. The
     * default parameter name is "x-frames-allow-from".
     *
     * @param allowFromParameterName the name of the HTTP parameter to
     */
    public void setAllowFromParameterName(String allowFromParameterName) {
        Assert.notNull(allowFromParameterName, "allowFromParameterName cannot be null");
        this.allowFromParameterName = allowFromParameterName;
    }

    /**
     * Method to be implemented by base classes, used to determine if the supplied origin is allowed.
     *
     * @param allowFromOrigin the supplied origin
     * @return <code>true</code> if the supplied origin is allowed.
     */
    protected abstract boolean allowed(String allowFromOrigin);
}

@@ -1250,24 +1250,8 @@
 turn
- %22ALLOW-FROM %22 +
  all

Remove double ALLOW-FROM from X-Frame-Options header.