Add SSL Configuration Library (#37287)

This introduces a new ssl-config library that can parse
and validate SSL/TLS settings and files.

It supports the standard configuration settings as used in the
Elastic Stack such as "ssl.verification_mode" and
"ssl.certificate_authorities" as well as all file formats used
in other parts of Elasticsearch security (such as PEM, JKS,
PKCS#12, PKCS#8, et al).

libs/ssl-config/build.gradle

@@ -0,0 +1,42 @@
+/*
+ * Licensed to Elasticsearch under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch licenses this file to you 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.
+ */
+
+dependencies {
+    compile "org.elasticsearch:elasticsearch-core:${version}"
+
+    if (isEclipse == false || project.path == ":libs:ssl-config-tests") {
+        testCompile("org.elasticsearch.test:framework:${version}") {
+            exclude group: 'org.elasticsearch', module: 'elasticsearch-ssl-config'
+        }
+    }
+
+    testCompile "com.carrotsearch.randomizedtesting:randomizedtesting-runner:${versions.randomizedrunner}"
+    testCompile "junit:junit:${versions.junit}"
+    testCompile "org.hamcrest:hamcrest-all:${versions.hamcrest}"
+}
+
+forbiddenApisMain {
+    replaceSignatureFiles 'jdk-signatures'
+}
+forbiddenPatterns {
+    exclude '**/*.key'
+    exclude '**/*.pem'
+    exclude '**/*.p12'
+    exclude '**/*.jks'
+}

libs/ssl-config/src/main/java/org/elasticsearch/common/ssl/DefaultJdkTrustConfig.java

@@ -0,0 +1,128 @@
+/*
+ * Licensed to Elasticsearch under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch licenses this file to you 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.elasticsearch.common.ssl;
+
+import org.elasticsearch.common.Nullable;
+
+import javax.net.ssl.TrustManagerFactory;
+import javax.net.ssl.X509ExtendedTrustManager;
+import java.io.IOException;
+import java.nio.file.Path;
+import java.security.GeneralSecurityException;
+import java.security.KeyStore;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.function.BiFunction;
+
+/**
+ * This class represents a trust configuration that corresponds to the default trusted CAs of the JDK
+ */
+final class DefaultJdkTrustConfig implements SslTrustConfig {
+
+    private final BiFunction<String, String, String> systemProperties;
+    private final char[] trustStorePassword;
+
+    /**
+     * Create a trust config that uses System properties to determine the TrustStore type, and the relevant password.
+     */
+    DefaultJdkTrustConfig() {
+        this(System::getProperty);
+    }
+
+    /**
+     * Create a trust config that uses supplied {@link BiFunction} to determine the TrustStore type, and the relevant password.
+     */
+    DefaultJdkTrustConfig(BiFunction<String, String, String> systemProperties) {
+        this(systemProperties, isPkcs11Truststore(systemProperties) ? getSystemTrustStorePassword(systemProperties) : null);
+    }
+
+    /**
+     * @param trustStorePassword the password for the truststore. It applies only when PKCS#11 tokens are used, is null otherwise
+     */
+    DefaultJdkTrustConfig(BiFunction<String, String, String> systemProperties, @Nullable char[] trustStorePassword) {
+        this.systemProperties = systemProperties;
+        this.trustStorePassword = trustStorePassword;
+    }
+
+    @Override
+    public X509ExtendedTrustManager createTrustManager() {
+        try {
+            return KeyStoreUtil.createTrustManager(getSystemTrustStore(), TrustManagerFactory.getDefaultAlgorithm());
+        } catch (GeneralSecurityException e) {
+            throw new SslConfigException("failed to initialize a TrustManager for the system keystore", e);
+        }
+    }
+
+    /**
+     * When a PKCS#11 token is used as the system default keystore/truststore, we need to pass the keystore
+     * password when loading, even for reading certificates only ( as opposed to i.e. JKS keystores where
+     * we only need to pass the password for reading Private Key entries ).
+     *
+     * @return the KeyStore used as truststore for PKCS#11 initialized with the password, null otherwise
+     */
+    private KeyStore getSystemTrustStore() {
+        if (isPkcs11Truststore(systemProperties) && trustStorePassword != null) {
+            try {
+                KeyStore keyStore = KeyStore.getInstance("PKCS11");
+                keyStore.load(null, trustStorePassword);
+                return keyStore;
+            } catch (GeneralSecurityException | IOException e) {
+                throw new SslConfigException("failed to load the system PKCS#11 truststore", e);
+            }
+        }
+        return null;
+    }
+
+    private static boolean isPkcs11Truststore(BiFunction<String, String, String> systemProperties) {
+        return systemProperties.apply("javax.net.ssl.trustStoreType", "").equalsIgnoreCase("PKCS11");
+    }
+
+    private static char[] getSystemTrustStorePassword(BiFunction<String, String, String> systemProperties) {
+        return systemProperties.apply("javax.net.ssl.trustStorePassword", "").toCharArray();
+    }
+
+    @Override
+    public Collection<Path> getDependentFiles() {
+        return Collections.emptyList();
+    }
+
+    @Override
+    public String toString() {
+        return "JDK-trusted-certs";
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) {
+            return true;
+        }
+        if (o == null || getClass() != o.getClass()) {
+            return false;
+        }
+        final DefaultJdkTrustConfig that = (DefaultJdkTrustConfig) o;
+        return Arrays.equals(this.trustStorePassword, that.trustStorePassword);
+    }
+
+    @Override
+    public int hashCode() {
+        return Arrays.hashCode(trustStorePassword);
+    }
+}