MINOR: Remove Deadcode in NioTransport CORS (#34324)

* Same as #34134 but for nio transport

plugins/transport-nio/src/main/java/org/elasticsearch/http/nio/cors/NioCorsConfig.java

@@ -48,7 +48,6 @@ public final class NioCorsConfig {
     private final long maxAge;
     private final Set<HttpMethod> allowedRequestMethods;
     private final Set<String> allowedRequestHeaders;
-    private final boolean allowNullOrigin;
     private final Map<CharSequence, Callable<?>> preflightHeaders;
     private final boolean shortCircuit;
 
@@ -61,7 +60,6 @@ public final class NioCorsConfig {
         maxAge = builder.maxAge;
         allowedRequestMethods = builder.requestMethods;
         allowedRequestHeaders = builder.requestHeaders;
-        allowNullOrigin = builder.allowNullOrigin;
         preflightHeaders = builder.preflightHeaders;
         shortCircuit = builder.shortCircuit;
     }
@@ -108,19 +106,6 @@ public boolean isOriginAllowed(final String origin) {
         return false;
     }
 
-    /**
-     * Web browsers may set the 'Origin' request header to 'null' if a resource is loaded
-     * from the local file system.
-     *
-     * If isNullOriginAllowed is true then the server will response with the wildcard for the
-     * the CORS response header 'Access-Control-Allow-Origin'.
-     *
-     * @return {@code true} if a 'null' origin should be supported.
-     */
-    public boolean isNullOriginAllowed() {
-        return allowNullOrigin;
-    }
-
     /**
      * Determines if credentials are supported for CORS requests.
      *

plugins/transport-nio/src/main/java/org/elasticsearch/http/nio/cors/NioCorsConfigBuilder.java

@@ -49,19 +49,6 @@ public static NioCorsConfigBuilder forAnyOrigin() {
         return new NioCorsConfigBuilder();
     }
 
-    /**
-     * Creates a {@link NioCorsConfigBuilder} instance with the specified origin.
-     *
-     * @return {@link NioCorsConfigBuilder} to support method chaining.
-     */
-    public static NioCorsConfigBuilder forOrigin(final String origin) {
-        if ("*".equals(origin)) {
-            return new NioCorsConfigBuilder();
-        }
-        return new NioCorsConfigBuilder(origin);
-    }
-
-
     /**
      * Create a {@link NioCorsConfigBuilder} instance with the specified pattern origin.
      *
@@ -87,14 +74,12 @@ public static NioCorsConfigBuilder forOrigins(final String... origins) {
     Optional<Set<String>> origins;
     Optional<Pattern> pattern;
     final boolean anyOrigin;
-    boolean allowNullOrigin;
     boolean enabled = true;
     boolean allowCredentials;
     long maxAge;
     final Set<HttpMethod> requestMethods = new HashSet<>();
     final Set<String> requestHeaders = new HashSet<>();
     final Map<CharSequence, Callable<?>> preflightHeaders = new HashMap<>();
-    private boolean noPreflightHeaders;
     boolean shortCircuit;
 
     /**
@@ -130,18 +115,6 @@ public static NioCorsConfigBuilder forOrigins(final String... origins) {
         anyOrigin = false;
     }
 
-    /**
-     * Web browsers may set the 'Origin' request header to 'null' if a resource is loaded
-     * from the local file system. Calling this method will enable a successful CORS response
-     * with a wildcard for the CORS response header 'Access-Control-Allow-Origin'.
-     *
-     * @return {@link NioCorsConfigBuilder} to support method chaining.
-     */
-    NioCorsConfigBuilder allowNullOrigin() {
-        allowNullOrigin = true;
-        return this;
-    }
-
     /**
      * Disables CORS support.
      *
@@ -219,71 +192,6 @@ public NioCorsConfigBuilder allowedRequestHeaders(final String... headers) {
         return this;
     }
 
-    /**
-     * Returns HTTP response headers that should be added to a CORS preflight response.
-     *
-     * An intermediary like a load balancer might require that a CORS preflight request
-     * have certain headers set. This enables such headers to be added.
-     *
-     * @param name the name of the HTTP header.
-     * @param values the values for the HTTP header.
-     * @return {@link NioCorsConfigBuilder} to support method chaining.
-     */
-    public NioCorsConfigBuilder preflightResponseHeader(final CharSequence name, final Object... values) {
-        if (values.length == 1) {
-            preflightHeaders.put(name, new ConstantValueGenerator(values[0]));
-        } else {
-            preflightResponseHeader(name, Arrays.asList(values));
-        }
-        return this;
-    }
-
-    /**
-     * Returns HTTP response headers that should be added to a CORS preflight response.
-     *
-     * An intermediary like a load balancer might require that a CORS preflight request
-     * have certain headers set. This enables such headers to be added.
-     *
-     * @param name the name of the HTTP header.
-     * @param value the values for the HTTP header.
-     * @param <T> the type of values that the Iterable contains.
-     * @return {@link NioCorsConfigBuilder} to support method chaining.
-     */
-    public <T> NioCorsConfigBuilder preflightResponseHeader(final CharSequence name, final Iterable<T> value) {
-        preflightHeaders.put(name, new ConstantValueGenerator(value));
-        return this;
-    }
-
-    /**
-     * Returns HTTP response headers that should be added to a CORS preflight response.
-     *
-     * An intermediary like a load balancer might require that a CORS preflight request
-     * have certain headers set. This enables such headers to be added.
-     *
-     * Some values must be dynamically created when the HTTP response is created, for
-     * example the 'Date' response header. This can be accomplished by using a Callable
-     * which will have its 'call' method invoked when the HTTP response is created.
-     *
-     * @param name the name of the HTTP header.
-     * @param valueGenerator a Callable which will be invoked at HTTP response creation.
-     * @param <T> the type of the value that the Callable can return.
-     * @return {@link NioCorsConfigBuilder} to support method chaining.
-     */
-    public <T> NioCorsConfigBuilder preflightResponseHeader(final CharSequence name, final Callable<T> valueGenerator) {
-        preflightHeaders.put(name, valueGenerator);
-        return this;
-    }
-
-    /**
-     * Specifies that no preflight response headers should be added to a preflight response.
-     *
-     * @return {@link NioCorsConfigBuilder} to support method chaining.
-     */
-    public NioCorsConfigBuilder noPreflightResponseHeaders() {
-        noPreflightHeaders = true;
-        return this;
-    }
-
     /**
      * Specifies that a CORS request should be rejected if it's invalid before being
      * further processing.
@@ -305,7 +213,7 @@ public NioCorsConfigBuilder shortCircuit() {
      * @return {@link NioCorsConfig} the configured CorsConfig instance.
      */
     public NioCorsConfig build() {
-        if (preflightHeaders.isEmpty() && !noPreflightHeaders) {
+        if (preflightHeaders.isEmpty()) {
             preflightHeaders.put("date", DateValueGenerator.INSTANCE);
             preflightHeaders.put("content-length", new ConstantValueGenerator("0"));
         }

plugins/transport-nio/src/main/java/org/elasticsearch/http/nio/cors/NioCorsHandler.java

@@ -167,11 +167,6 @@ private void setPreflightHeaders(final HttpResponse response) {
     private boolean setOrigin(final HttpResponse response) {
         final String origin = request.headers().get(HttpHeaderNames.ORIGIN);
         if (!Strings.isNullOrEmpty(origin)) {
-            if ("null".equals(origin) && config.isNullOriginAllowed()) {
-                setAnyOrigin(response);
-                return true;
-            }
-
             if (config.isAnyOriginSupported()) {
                 if (config.isCredentialsAllowed()) {
                     echoRequestOrigin(response);
@@ -201,10 +196,6 @@ private boolean validateOrigin() {
             return true;
         }
 
-        if ("null".equals(origin) && config.isNullOriginAllowed()) {
-            return true;
-        }
-
         // if the origin is the same as the host of the request, then allow
         if (isSameOrigin(origin, request.headers().get(HttpHeaderNames.HOST))) {
             return true;