Upgrade to Tomcat 11.0.18

Tomcat 9.0.115, 10.1.52, and 11.0.18 include a breaking change [1] to
how ciphers are configured when using HTTPS. Previously, a single
setting was used but this has now been split in two; the existing
ciphers setting for TLSv1.2 ciphers and a new ciperSuites setting for
TLSv1.3. As part of this split, the behavior of the ciphers setting
has been changed such that any TLSv1.3 ciphers are ignored and a
warning is logged.

This change in Tomcat is problematic without also making some changes
in Boot. If we had done nothing, a user that had configured only
TLSv1.3 cipers would have them all ignored, leaving their SSL
connection unexpectedly using all of the default ciphers which may be
less secure.

This commit adapts to the breaking change in Tomcat by taking the
user's list of ciphers and splitting into into TLSv1.2 and TLSv1.3
ciphers before passing them into Tomcat's two settings (ciphers and
cipherSuites respectively). This is done defensively for backwards
compatibility. If the methods to identify and configure the TLSv1.3
ciphers are not present, we assume that we're running with an earlier
version of Tomcat and fall back to passing them all into the ciphers
setting as we did previously.

Closes gh-49108

[1] apache/tomcat@9abf6bd

Author: wilkinsona

gradle.properties

@@ -23,6 +23,6 @@ nullabilityPluginVersion=0.0.11
 snakeYamlVersion=2.5
 springFrameworkVersion=7.0.4-SNAPSHOT
 springFramework60xVersion=6.0.23
-tomcatVersion=11.0.15
+tomcatVersion=11.0.18
 
 kotlin.stdlib.default.dependency=false

module/spring-boot-tomcat/src/main/java/org/springframework/boot/tomcat/SslConnectorCustomizer.java

@@ -16,6 +16,8 @@
 
 package org.springframework.boot.tomcat;
 
+import java.util.ArrayList;
+import java.util.List;
 import java.util.Map;
 
 import org.apache.catalina.connector.Connector;
@@ -25,6 +27,7 @@
 import org.apache.tomcat.util.net.SSLHostConfig;
 import org.apache.tomcat.util.net.SSLHostConfigCertificate;
 import org.apache.tomcat.util.net.SSLHostConfigCertificate.Type;
+import org.apache.tomcat.util.net.openssl.ciphers.OpenSSLCipherConfigurationParser;
 import org.jspecify.annotations.Nullable;
 
 import org.springframework.boot.ssl.SslBundle;
@@ -113,14 +116,24 @@ private void applySslBundle(AbstractHttp11Protocol<?> protocol, SSLHostConfig ss
 			certificate.setCertificateKeyAlias(key.getAlias());
 		}
 		sslHostConfig.addCertificate(certificate);
-		if (options.getCiphers() != null) {
-			String ciphers = StringUtils.arrayToCommaDelimitedString(options.getCiphers());
-			sslHostConfig.setCiphers(ciphers);
-		}
+		configureCiphers(options, sslHostConfig);
 		configureSslStores(sslHostConfig, certificate, stores);
 		configureEnabledProtocols(sslHostConfig, options);
 	}
 
+	private void configureCiphers(SslOptions options, SSLHostConfig sslHostConfig) {
+		CipherConfiguration cipherConfiguration = CipherConfiguration.from(options);
+		if (cipherConfiguration != null) {
+			sslHostConfig.setCiphers(cipherConfiguration.tls12Ciphers);
+			try {
+				sslHostConfig.setCipherSuites(cipherConfiguration.tls13Ciphers);
+			}
+			catch (Exception ex) {
+				// Tomcat version without setCipherSuites method. Continue.
+			}
+		}
+	}
+
 	private void configureEnabledProtocols(SSLHostConfig sslHostConfig, SslOptions options) {
 		if (options.getEnabledProtocols() != null) {
 			String enabledProtocols = StringUtils.arrayToDelimitedString(options.getEnabledProtocols(), "+");
@@ -147,4 +160,47 @@ private void configureSslStores(SSLHostConfig sslHostConfig, SSLHostConfigCertif
 		}
 	}
 
+	private static class CipherConfiguration {
+
+		private final String tls12Ciphers;
+
+		private final String tls13Ciphers;
+
+		CipherConfiguration(String tls12Ciphers, String tls13Ciphers) {
+			this.tls12Ciphers = tls12Ciphers;
+			this.tls13Ciphers = tls13Ciphers;
+		}
+
+		static @Nullable CipherConfiguration from(SslOptions options) {
+			List<String> tls12Ciphers = new ArrayList<>();
+			List<String> tls13Ciphers = new ArrayList<>();
+			String[] ciphers = options.getCiphers();
+			if (ciphers == null || ciphers.length == 0) {
+				return null;
+			}
+			for (String cipher : ciphers) {
+				if (isTls13(cipher)) {
+					tls13Ciphers.add(cipher);
+				}
+				else {
+					tls12Ciphers.add(cipher);
+				}
+			}
+			return new CipherConfiguration(StringUtils.collectionToCommaDelimitedString(tls12Ciphers),
+					StringUtils.collectionToCommaDelimitedString(tls13Ciphers));
+		}
+
+		private static boolean isTls13(String cipher) {
+			try {
+				return OpenSSLCipherConfigurationParser.isTls13Cipher(cipher);
+			}
+			catch (Exception ex) {
+				// Tomcat version without isTls13Cipher method. Continue, treating all
+				// ciphers as TLSv1.2
+				return false;
+			}
+		}
+
+	}
+
 }

module/spring-boot-tomcat/src/test/java/org/springframework/boot/tomcat/SslConnectorCustomizerTests.java

@@ -23,6 +23,7 @@
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.apache.tomcat.util.net.SSLHostConfig;
+import org.apache.tomcat.util.net.openssl.ciphers.Cipher;
 import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
@@ -73,7 +74,7 @@ void stop() throws Exception {
 
 	@Test
 	@WithPackageResources("test.jks")
-	void sslCiphersConfiguration() throws Exception {
+	void tls12CiphersConfiguration() throws Exception {
 		Ssl ssl = new Ssl();
 		ssl.setKeyStore("classpath:test.jks");
 		ssl.setKeyStorePassword("secret");
@@ -84,6 +85,42 @@ void sslCiphersConfiguration() throws Exception {
 		this.tomcat.start();
 		SSLHostConfig[] sslHostConfigs = connector.getProtocolHandler().findSslHostConfigs();
 		assertThat(sslHostConfigs[0].getCiphers()).isEqualTo("ALPHA:BRAVO:CHARLIE");
+		assertThat(sslHostConfigs[0].getCipherSuites()).isEmpty();
+	}
+
+	@Test
+	@WithPackageResources("test.jks")
+	void tls13CiphersConfiguration() throws Exception {
+		Ssl ssl = new Ssl();
+		ssl.setKeyStore("classpath:test.jks");
+		ssl.setKeyStorePassword("secret");
+		ssl.setCiphers(new String[] { Cipher.TLS_AES_128_CCM_SHA256.getOpenSSLAlias(),
+				Cipher.TLS_AES_256_GCM_SHA384.getOpenSSLAlias() });
+		Connector connector = this.tomcat.getConnector();
+		SslConnectorCustomizer customizer = new SslConnectorCustomizer(this.logger, connector, ssl.getClientAuth());
+		customizer.customize(WebServerSslBundle.get(ssl), Collections.emptyMap());
+		this.tomcat.start();
+		SSLHostConfig[] sslHostConfigs = connector.getProtocolHandler().findSslHostConfigs();
+		assertThat(sslHostConfigs[0].getCiphers()).isEmpty();
+		assertThat(sslHostConfigs[0].getCipherSuites()).isEqualTo("TLS_AES_128_CCM_SHA256:TLS_AES_256_GCM_SHA384");
+	}
+
+	@Test
+	@WithPackageResources("test.jks")
+	void mixedTls12AndTls13CiphersConfiguration() throws Exception {
+		Ssl ssl = new Ssl();
+		ssl.setKeyStore("classpath:test.jks");
+		ssl.setKeyStorePassword("secret");
+		ssl.setCiphers(new String[] { Cipher.TLS_AES_128_CCM_SHA256.getOpenSSLAlias(),
+				Cipher.TLS_DH_DSS_WITH_AES_128_CBC_SHA256.getOpenSSLAlias(),
+				Cipher.TLS_AES_256_GCM_SHA384.getOpenSSLAlias() });
+		Connector connector = this.tomcat.getConnector();
+		SslConnectorCustomizer customizer = new SslConnectorCustomizer(this.logger, connector, ssl.getClientAuth());
+		customizer.customize(WebServerSslBundle.get(ssl), Collections.emptyMap());
+		this.tomcat.start();
+		SSLHostConfig[] sslHostConfigs = connector.getProtocolHandler().findSslHostConfigs();
+		assertThat(sslHostConfigs[0].getCiphers()).isEqualTo("DH-DSS-AES128-SHA256");
+		assertThat(sslHostConfigs[0].getCipherSuites()).isEqualTo("TLS_AES_128_CCM_SHA256:TLS_AES_256_GCM_SHA384");
 	}
 
 	@Test