Add ForwardAuthenticationFailureHandler

Fixes gh-3727

web/src/main/java/org/springframework/security/web/authentication/ForwardAuthenticationFailureHandler.java

@@ -0,0 +1,54 @@
+/*
+ * Copyright 2002-2016 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.security.web.authentication;
+
+import org.springframework.security.core.AuthenticationException;
+import org.springframework.security.web.WebAttributes;
+import org.springframework.security.web.util.UrlUtils;
+import org.springframework.util.Assert;
+
+import javax.servlet.ServletException;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import java.io.IOException;
+
+/**
+ * <p>
+ * Forward Authentication Failure Handler
+ * </p>
+ *
+ * @author Shazin Sadakath
+ *
+ */
+public class ForwardAuthenticationFailureHandler implements AuthenticationFailureHandler {
+
+	private final String forwardUrl;
+
+	/**
+	 * @param forwardUrl
+	 */
+	public ForwardAuthenticationFailureHandler(String forwardUrl) {
+        Assert.isTrue(UrlUtils.isValidRedirectUrl(forwardUrl), "'"
+                + forwardUrl + "' is not a valid forward URL");
+		this.forwardUrl = forwardUrl;
+	}
+
+	@Override
+	public void onAuthenticationFailure(HttpServletRequest request, HttpServletResponse response, AuthenticationException exception) throws IOException, ServletException {
+		request.setAttribute(WebAttributes.AUTHENTICATION_EXCEPTION, exception);
+		request.getRequestDispatcher(forwardUrl).forward(request, response);
+	}
+}

web/src/test/java/org/springframework/security/web/authentication/ForwardAuthenticationFailureHandlerTests.java

@@ -0,0 +1,60 @@
+/*
+ * Copyright 2002-2016 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.security.web.authentication;
+
+import org.junit.Test;
+import org.springframework.mock.web.MockHttpServletRequest;
+import org.springframework.mock.web.MockHttpServletResponse;
+import org.springframework.security.core.AuthenticationException;
+import org.springframework.security.web.WebAttributes;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.Mockito.mock;
+
+/**
+ * <p>
+ * Forward Authentication Failure Handler Tests
+ * </p>
+ *
+ * @author Shazin Sadakath
+ *
+ */
+public class ForwardAuthenticationFailureHandlerTests {
+
+	@Test(expected = IllegalArgumentException.class)
+	public void invalidForwardUrl() {
+		new ForwardAuthenticationFailureHandler("aaa");
+	}
+
+	@Test(expected = IllegalArgumentException.class)
+	public void emptyForwardUrl() {
+		new ForwardAuthenticationFailureHandler("");
+	}
+
+	@Test
+	public void responseIsForwarded() throws Exception {
+		ForwardAuthenticationFailureHandler fafh = new ForwardAuthenticationFailureHandler("/forwardUrl");
+
+		MockHttpServletRequest request = new MockHttpServletRequest();
+		MockHttpServletResponse response = new MockHttpServletResponse();
+		AuthenticationException e = mock(AuthenticationException.class);
+
+		fafh.onAuthenticationFailure(request, response, e);
+
+		assertThat(response.getForwardedUrl()).isEqualTo("/forwardUrl");
+        assertThat(request.getAttribute(WebAttributes.AUTHENTICATION_EXCEPTION)).isEqualTo(e);
+	}
+}