Merge pull request #16278 from Rafiullah Hamedy

* gh-16278:
  Polish "Add support for configuring remaining Undertow server options"
  Add support for configuring remaining Undertow server options

Closes gh-16278

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/ServerProperties.java

@@ -29,6 +29,8 @@ import java.util.Locale;
 import java.util.Map;
 import java.util.TimeZone;
 
+import io.undertow.UndertowOptions;
+
 import org.springframework.boot.context.properties.ConfigurationProperties;
 import org.springframework.boot.context.properties.DeprecatedConfigurationProperty;
 import org.springframework.boot.context.properties.NestedConfigurationProperty;
@@ -58,6 +60,8 @@ import org.springframework.util.unit.DataSize;
  * @author Chentao Qu
  * @author Artsiom Yudovin
  * @author Andrew McGhie
+ * @author Rafiullah Hamedy
+ *
  */
 @ConfigurationProperties(prefix = "server", ignoreUnknownFields = true)
 public class ServerProperties {
@@ -1114,6 +1118,49 @@ public class ServerProperties {
 		 */
 		private boolean eagerFilterInit = true;
 
+		/**
+		 * Maximum number of query or path parameters that are allowed. This limit exists
+		 * to prevent hash collision based DOS attacks.
+		 */
+		private int maxParameters = UndertowOptions.DEFAULT_MAX_PARAMETERS;
+
+		/**
+		 * Maximum number of headers that are allowed. This limit exists to prevent hash
+		 * collision based DOS attacks.
+		 */
+		private int maxHeaders = UndertowOptions.DEFAULT_MAX_HEADERS;
+
+		/**
+		 * Maximum number of cookies that are allowed. This limit exists to prevent hash
+		 * collision based DOS attacks.
+		 */
+		private int maxCookies = 200;
+
+		/**
+		 * Whether the server should decode percent encoded slash characters. Enabling
+		 * encoded slashes can have security implications due to different servers
+		 * interpreting the slash differently. Only enable this if you have a legacy
+		 * application that requires it.
+		 */
+		private boolean allowEncodedSlash = false;
+
+		/**
+		 * Whether the URL should be decoded. When disabled, percent-encoded characters in
+		 * the URL will be left as-is.
+		 */
+		private boolean decodeUrl = true;
+
+		/**
+		 * Charset used to decode URLs.
+		 */
+		private Charset urlCharset = StandardCharsets.UTF_8;
+
+		/**
+		 * Whether the 'Connection: keep-alive' header should be added to all responses,
+		 * even if not required by the HTTP specification.
+		 */
+		private boolean alwaysSetKeepAlive = true;
+
 		private final Accesslog accesslog = new Accesslog();
 
 		public DataSize getMaxHttpPostSize() {
@@ -1164,6 +1211,62 @@ public class ServerProperties {
 			this.eagerFilterInit = eagerFilterInit;
 		}
 
+		public int getMaxParameters() {
+			return this.maxParameters;
+		}
+
+		public void setMaxParameters(Integer maxParameters) {
+			this.maxParameters = maxParameters;
+		}
+
+		public int getMaxHeaders() {
+			return this.maxHeaders;
+		}
+
+		public void setMaxHeaders(int maxHeaders) {
+			this.maxHeaders = maxHeaders;
+		}
+
+		public Integer getMaxCookies() {
+			return this.maxCookies;
+		}
+
+		public void setMaxCookies(Integer maxCookies) {
+			this.maxCookies = maxCookies;
+		}
+
+		public boolean isAllowEncodedSlash() {
+			return this.allowEncodedSlash;
+		}
+
+		public void setAllowEncodedSlash(boolean allowEncodedSlash) {
+			this.allowEncodedSlash = allowEncodedSlash;
+		}
+
+		public boolean isDecodeUrl() {
+			return this.decodeUrl;
+		}
+
+		public void setDecodeUrl(Boolean decodeUrl) {
+			this.decodeUrl = decodeUrl;
+		}
+
+		public Charset getUrlCharset() {
+			return this.urlCharset;
+		}
+
+		public void setUrlCharset(Charset urlCharset) {
+			this.urlCharset = urlCharset;
+		}
+
+		public boolean isAlwaysSetKeepAlive() {
+			return this.alwaysSetKeepAlive;
+		}
+
+		public void setAlwaysSetKeepAlive(boolean alwaysSetKeepAlive) {
+			this.alwaysSetKeepAlive = alwaysSetKeepAlive;
+		}
+
 		public Accesslog getAccesslog() {
 			return this.accesslog;
 		}

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/embedded/UndertowWebServerFactoryCustomizer.java

@@ -16,9 +16,8 @@
 
 package org.springframework.boot.autoconfigure.web.embedded;
 
-import java.time.Duration;
-
 import io.undertow.UndertowOptions;
+import org.xnio.Option;
 
 import org.springframework.boot.autoconfigure.web.ServerProperties;
 import org.springframework.boot.cloud.CloudPlatform;
@@ -38,6 +37,7 @@ import org.springframework.util.unit.DataSize;
  * @author Stephane Nicoll
  * @author Phillip Webb
  * @author Arstiom Yudovin
+ * @author Rafiullah Hamedy
  * @since 2.0.0
  */
 public class UndertowWebServerFactoryCustomizer implements
@@ -86,17 +86,50 @@ public class UndertowWebServerFactoryCustomizer implements
 				.to(factory::setAccessLogRotate);
 		propertyMapper.from(this::getOrDeduceUseForwardHeaders)
 				.to(factory::setUseForwardHeaders);
+
 		propertyMapper.from(properties::getMaxHttpHeaderSize).whenNonNull()
 				.asInt(DataSize::toBytes).when(this::isPositive)
-				.to((maxHttpHeaderSize) -> customizeMaxHttpHeaderSize(factory,
-						maxHttpHeaderSize));
-		propertyMapper.from(undertowProperties::getMaxHttpPostSize)
-				.asInt(DataSize::toBytes).when(this::isPositive)
-				.to((maxHttpPostSize) -> customizeMaxHttpPostSize(factory,
-						maxHttpPostSize));
+				.to((maxHttpHeaderSize) -> customizeServerOption(factory,
+						UndertowOptions.MAX_HEADER_SIZE, maxHttpHeaderSize));
+
+		propertyMapper.from(undertowProperties::getMaxHttpPostSize).as(DataSize::toBytes)
+				.when(this::isPositive)
+				.to((maxHttpPostSize) -> customizeServerOption(factory,
+						UndertowOptions.MAX_ENTITY_SIZE, maxHttpPostSize));
+
 		propertyMapper.from(properties::getConnectionTimeout)
-				.to((connectionTimeout) -> customizeConnectionTimeout(factory,
-						connectionTimeout));
+				.to((connectionTimeout) -> customizeServerOption(factory,
+						UndertowOptions.NO_REQUEST_TIMEOUT,
+						(int) connectionTimeout.toMillis()));
+
+		propertyMapper.from(undertowProperties::getMaxParameters)
+				.to((maxParameters) -> customizeServerOption(factory,
+						UndertowOptions.MAX_PARAMETERS, maxParameters));
+
+		propertyMapper.from(undertowProperties::getMaxHeaders)
+				.to((maxHeaders) -> customizeServerOption(factory,
+						UndertowOptions.MAX_HEADERS, maxHeaders));
+
+		propertyMapper.from(undertowProperties::getMaxCookies)
+				.to((maxCookies) -> customizeServerOption(factory,
+						UndertowOptions.MAX_COOKIES, maxCookies));
+
+		propertyMapper.from(undertowProperties::isAllowEncodedSlash)
+				.to((allowEncodedSlash) -> customizeServerOption(factory,
+						UndertowOptions.ALLOW_ENCODED_SLASH, allowEncodedSlash));
+
+		propertyMapper.from(undertowProperties::isDecodeUrl)
+				.to((isDecodeUrl) -> customizeServerOption(factory,
+						UndertowOptions.DECODE_URL, isDecodeUrl));
+
+		propertyMapper.from(undertowProperties::getUrlCharset)
+				.to((urlCharset) -> customizeServerOption(factory,
+						UndertowOptions.URL_CHARSET, urlCharset.name()));
+
+		propertyMapper.from(undertowProperties::isAlwaysSetKeepAlive)
+				.to((alwaysSetKeepAlive) -> customizeServerOption(factory,
+						UndertowOptions.ALWAYS_SET_KEEP_ALIVE, alwaysSetKeepAlive));
+
 		factory.addDeploymentInfoCustomizers((deploymentInfo) -> deploymentInfo
 				.setEagerFilterInit(undertowProperties.isEagerFilterInit()));
 	}
@@ -105,22 +138,10 @@ public class UndertowWebServerFactoryCustomizer implements
 		return value.longValue() > 0;
 	}
 
-	private void customizeConnectionTimeout(ConfigurableUndertowWebServerFactory factory,
-			Duration connectionTimeout) {
-		factory.addBuilderCustomizers((builder) -> builder.setServerOption(
-				UndertowOptions.NO_REQUEST_TIMEOUT, (int) connectionTimeout.toMillis()));
-	}
-
-	private void customizeMaxHttpHeaderSize(ConfigurableUndertowWebServerFactory factory,
-			int maxHttpHeaderSize) {
-		factory.addBuilderCustomizers((builder) -> builder
-				.setServerOption(UndertowOptions.MAX_HEADER_SIZE, maxHttpHeaderSize));
-	}
-
-	private void customizeMaxHttpPostSize(ConfigurableUndertowWebServerFactory factory,
-			long maxHttpPostSize) {
-		factory.addBuilderCustomizers((builder) -> builder
-				.setServerOption(UndertowOptions.MAX_ENTITY_SIZE, maxHttpPostSize));
+	private <T> void customizeServerOption(ConfigurableUndertowWebServerFactory factory,
+			Option<T> option, T value) {
+		factory.addBuilderCustomizers(
+				(builder) -> builder.setServerOption(option, value));
 	}
 
 	private boolean getOrDeduceUseForwardHeaders() {

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/web/embedded/UndertowWebServerFactoryCustomizerTests.java

@@ -17,6 +17,7 @@
 package org.springframework.boot.autoconfigure.web.embedded;
 
 import java.io.File;
+import java.nio.charset.StandardCharsets;
 import java.util.Arrays;
 
 import io.undertow.Undertow;
@@ -24,6 +25,7 @@ import io.undertow.Undertow.Builder;
 import io.undertow.UndertowOptions;
 import org.junit.Before;
 import org.junit.Test;
+import org.xnio.Option;
 import org.xnio.OptionMap;
 
 import org.springframework.boot.autoconfigure.web.ServerProperties;
@@ -48,6 +50,8 @@ import static org.mockito.Mockito.verify;
  * @author Brian Clozel
  * @author Phillip Webb
  * @author Artsiom Yudovin
+ * @author Rafiullah Hamedy
+ *
  */
 public class UndertowWebServerFactoryCustomizerTests {
 
@@ -85,6 +89,78 @@ public class UndertowWebServerFactoryCustomizerTests {
 		verify(factory).setAccessLogRotate(false);
 	}
 
+	@Test
+	public void customMaxHttpHeaderSize() {
+		bind("server.max-http-header-size=2048");
+		assertThat(boundServerOption(UndertowOptions.MAX_HEADER_SIZE)).isEqualTo(2048);
+	}
+
+	@Test
+	public void customMaxHttpHeaderSizeIgnoredIfNegative() {
+		bind("server.max-http-header-size=-1");
+		assertThat(boundServerOption(UndertowOptions.MAX_HEADER_SIZE)).isNull();
+	}
+
+	public void customMaxHttpHeaderSizeIgnoredIfZero() {
+		bind("server.max-http-header-size=0");
+		assertThat(boundServerOption(UndertowOptions.MAX_HEADER_SIZE)).isNull();
+	}
+
+	@Test
+	public void customMaxHttpPostSize() {
+		bind("server.undertow.max-http-post-size=256");
+		assertThat(boundServerOption(UndertowOptions.MAX_ENTITY_SIZE)).isEqualTo(256);
+	}
+
+	@Test
+	public void customConnectionTimeout() {
+		bind("server.connectionTimeout=100");
+		assertThat(boundServerOption(UndertowOptions.NO_REQUEST_TIMEOUT)).isEqualTo(100);
+	}
+
+	@Test
+	public void customMaxParameters() {
+		bind("server.undertow.max-parameters=4");
+		assertThat(boundServerOption(UndertowOptions.MAX_PARAMETERS)).isEqualTo(4);
+	}
+
+	@Test
+	public void customMaxHeaders() {
+		bind("server.undertow.max-headers=4");
+		assertThat(boundServerOption(UndertowOptions.MAX_HEADERS)).isEqualTo(4);
+	}
+
+	@Test
+	public void customMaxCookies() {
+		bind("server.undertow.max-cookies=4");
+		assertThat(boundServerOption(UndertowOptions.MAX_COOKIES)).isEqualTo(4);
+	}
+
+	@Test
+	public void allowEncodedSlashes() {
+		bind("server.undertow.allow-encoded-slash=true");
+		assertThat(boundServerOption(UndertowOptions.ALLOW_ENCODED_SLASH)).isTrue();
+	}
+
+	@Test
+	public void disableUrlDecoding() {
+		bind("server.undertow.decode-url=false");
+		assertThat(boundServerOption(UndertowOptions.DECODE_URL)).isFalse();
+	}
+
+	@Test
+	public void customUrlCharset() {
+		bind("server.undertow.url-charset=UTF-16");
+		assertThat(boundServerOption(UndertowOptions.URL_CHARSET))
+				.isEqualTo(StandardCharsets.UTF_16.name());
+	}
+
+	@Test
+	public void disableAlwaysSetKeepAlive() {
+		bind("server.undertow.always-set-keep-alive=false");
+		assertThat(boundServerOption(UndertowOptions.ALWAYS_SET_KEEP_ALIVE)).isFalse();
+	}
+
 	@Test
 	public void deduceUseForwardHeaders() {
 		this.environment.setProperty("DYNO", "-");
@@ -111,49 +187,13 @@ public class UndertowWebServerFactoryCustomizerTests {
 		verify(factory).setUseForwardHeaders(true);
 	}
 
-	@Test
-	public void customizeMaxHttpHeaderSize() {
-		bind("server.max-http-header-size=2048");
-		Builder builder = Undertow.builder();
-		ConfigurableUndertowWebServerFactory factory = mockFactory(builder);
-		this.customizer.customize(factory);
-		OptionMap map = ((OptionMap.Builder) ReflectionTestUtils.getField(builder,
-				"serverOptions")).getMap();
-		assertThat(map.get(UndertowOptions.MAX_HEADER_SIZE).intValue()).isEqualTo(2048);
-	}
-
-	@Test
-	public void customMaxHttpHeaderSizeIgnoredIfNegative() {
-		bind("server.max-http-header-size=-1");
-		Builder builder = Undertow.builder();
-		ConfigurableUndertowWebServerFactory factory = mockFactory(builder);
-		this.customizer.customize(factory);
-		OptionMap map = ((OptionMap.Builder) ReflectionTestUtils.getField(builder,
-				"serverOptions")).getMap();
-		assertThat(map.contains(UndertowOptions.MAX_HEADER_SIZE)).isFalse();
-	}
-
-	@Test
-	public void customMaxHttpHeaderSizeIgnoredIfZero() {
-		bind("server.max-http-header-size=0");
-		Builder builder = Undertow.builder();
-		ConfigurableUndertowWebServerFactory factory = mockFactory(builder);
-		this.customizer.customize(factory);
-		OptionMap map = ((OptionMap.Builder) ReflectionTestUtils.getField(builder,
-				"serverOptions")).getMap();
-		assertThat(map.contains(UndertowOptions.MAX_HEADER_SIZE)).isFalse();
-	}
-
-	@Test
-	public void customConnectionTimeout() {
-		bind("server.connection-timeout=100");
+	private <T> T boundServerOption(Option<T> option) {
 		Builder builder = Undertow.builder();
 		ConfigurableUndertowWebServerFactory factory = mockFactory(builder);
 		this.customizer.customize(factory);
 		OptionMap map = ((OptionMap.Builder) ReflectionTestUtils.getField(builder,
 				"serverOptions")).getMap();
-		assertThat(map.contains(UndertowOptions.NO_REQUEST_TIMEOUT)).isTrue();
-		assertThat(map.get(UndertowOptions.NO_REQUEST_TIMEOUT)).isEqualTo(100);
+		return map.get(option);
 	}
 
 	private ConfigurableUndertowWebServerFactory mockFactory(Builder builder) {