Add support for configuring Tomcat's relaxed path and query chars

See gh-17510

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

@@ -61,6 +61,7 @@ import org.springframework.util.unit.DataSize;
  * @author Artsiom Yudovin
  * @author Andrew McGhie
  * @author Rafiullah Hamedy
+ * @author Dirk Deyne
  * @since 1.0.0
  */
 @ConfigurationProperties(prefix = "server", ignoreUnknownFields = true)
@@ -405,6 +406,20 @@ public class ServerProperties {
 		 */
 		private final Mbeanregistry mbeanregistry = new Mbeanregistry();
 
+		/**
+		 * Specify additional unencoded characters that Tomcat should allow in a
+		 * querystring. The value may be any combination of the following characters: " <
+		 * > [ \ ] ^ ` { | } . Any other characters present in the value will be ignored.
+		 */
+		private String relaxedQueryChars;
+
+		/**
+		 * Specify additional unencoded characters that Tomcat should allow in the path.
+		 * The value may be any combination of the following characters: " < > [ \ ] ^ ` {
+		 * | } . Any other characters present in the value will be ignored.
+		 */
+		private String relaxedPathChars;
+
 		public int getMaxThreads() {
 			return this.maxThreads;
 		}
@@ -561,6 +576,22 @@ public class ServerProperties {
 			return this.mbeanregistry;
 		}
 
+		public String getRelaxedPathChars() {
+			return this.relaxedPathChars;
+		}
+
+		public void setRelaxedPathChars(String relaxedPathChars) {
+			this.relaxedPathChars = relaxedPathChars;
+		}
+
+		public String getRelaxedQueryChars() {
+			return this.relaxedQueryChars;
+		}
+
+		public void setRelaxedQueryChars(String relaxedQueryChars) {
+			this.relaxedQueryChars = relaxedQueryChars;
+		}
+
 		/**
 		 * Tomcat access log properties.
 		 */

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

@@ -51,6 +51,7 @@ import org.springframework.util.unit.DataSize;
  * @author Artsiom Yudovin
  * @author Chentao Qu
  * @author Andrew McGhie
+ * @author Dirk Deyne
  * @since 2.0.0
  */
 public class TomcatWebServerFactoryCustomizer
@@ -102,6 +103,10 @@ public class TomcatWebServerFactoryCustomizer
 				.to((acceptCount) -> customizeAcceptCount(factory, acceptCount));
 		propertyMapper.from(tomcatProperties::getProcessorCache)
 				.to((processorCache) -> customizeProcessorCache(factory, processorCache));
+		propertyMapper.from(tomcatProperties::getRelaxedQueryChars)
+				.to((relaxedChars) -> customizeRelaxedQueryChars(factory, relaxedChars));
+		propertyMapper.from(tomcatProperties::getRelaxedPathChars)
+				.to((relaxedChars) -> customizeRelaxedPathChars(factory, relaxedChars));
 		customizeStaticResources(factory);
 		customizeErrorReportValve(properties.getError(), factory);
 	}
@@ -149,6 +154,14 @@ public class TomcatWebServerFactoryCustomizer
 		});
 	}
 
+	private void customizeRelaxedQueryChars(ConfigurableTomcatWebServerFactory factory, String relaxedChars) {
+		factory.addConnectorCustomizers((connector) -> connector.setAttribute("relaxedQueryChars", relaxedChars));
+	}
+
+	private void customizeRelaxedPathChars(ConfigurableTomcatWebServerFactory factory, String relaxedChars) {
+		factory.addConnectorCustomizers((connector) -> connector.setAttribute("relaxedPathChars", relaxedChars));
+	}
+
 	private void customizeRemoteIpValve(ConfigurableTomcatWebServerFactory factory) {
 		Tomcat tomcatProperties = this.serverProperties.getTomcat();
 		String protocolHeader = tomcatProperties.getProtocolHeader();

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

@@ -127,6 +127,8 @@ class ServerPropertiesTests {
 		map.put("server.tomcat.remote-ip-header", "Remote-Ip");
 		map.put("server.tomcat.internal-proxies", "10\\.\\d{1,3}\\.\\d{1,3}\\.\\d{1,3}");
 		map.put("server.tomcat.background-processor-delay", "10");
+		map.put("server.tomcat.relaxed-path-chars", "|");
+		map.put("server.tomcat.relaxed-query-chars", "^^");
 		bind(map);
 		ServerProperties.Tomcat tomcat = this.properties.getTomcat();
 		Accesslog accesslog = tomcat.getAccesslog();
@@ -146,6 +148,8 @@ class ServerPropertiesTests {
 		assertThat(tomcat.getProtocolHeader()).isEqualTo("X-Forwarded-Protocol");
 		assertThat(tomcat.getInternalProxies()).isEqualTo("10\\.\\d{1,3}\\.\\d{1,3}\\.\\d{1,3}");
 		assertThat(tomcat.getBackgroundProcessorDelay()).isEqualTo(Duration.ofSeconds(10));
+		assertThat(tomcat.getRelaxedPathChars()).isEqualTo("|");
+		assertThat(tomcat.getRelaxedQueryChars()).isEqualTo("^^");
 	}
 
 	@Test