add option to bypass certificate validation

CHANGELOG.next-release.md

@@ -1 +1 @@
-
+* Add support of `elastic.otel.verify.server.cert` config option to disable server certificate validation - #726

custom/src/main/java/co/elastic/otel/ElasticAutoConfigurationCustomizerProvider.java

@@ -62,9 +62,26 @@ public class ElasticAutoConfigurationCustomizerProvider
 
   @Override
   public void customize(AutoConfigurationCustomizer autoConfiguration) {
-    // Order is important: configureExporterUserAgentHeaders needs access to the unwrapped exporters
-    configureExporterUserAgentHeaders(autoConfiguration);
-    configureBlockableExporters(autoConfiguration);
+    // Order is important: headers and server certificate bypass need access to the unwrapped
+    // exporters and must execute first
+    autoConfiguration.addSpanExporterCustomizer(
+        (exporter, config) -> {
+          exporter = ElasticUserAgentHeader.configureIfPossible(exporter);
+          exporter = ElasticVerifyServerCert.configureIfPossible(exporter, config);
+          return BlockableSpanExporter.createCustomInstance(exporter);
+        });
+    autoConfiguration.addMetricExporterCustomizer(
+        (exporter, config) -> {
+          exporter = ElasticUserAgentHeader.configureIfPossible(exporter);
+          exporter = ElasticVerifyServerCert.configureIfPossible(exporter, config);
+          return BlockableMetricExporter.createCustomInstance(exporter);
+        });
+    autoConfiguration.addLogRecordExporterCustomizer(
+        (exporter, config) -> {
+          exporter = ElasticUserAgentHeader.configureIfPossible(exporter);
+          exporter = ElasticVerifyServerCert.configureIfPossible(exporter, config);
+          return BlockableLogRecordExporter.createCustomInstance(exporter);
+        });
 
     autoConfiguration.addPropertiesCustomizer(
         ElasticAutoConfigurationCustomizerProvider::propertiesCustomizer);
@@ -78,29 +95,6 @@ public void customize(AutoConfigurationCustomizer autoConfiguration) {
         });
   }
 
-  private void configureExporterUserAgentHeaders(AutoConfigurationCustomizer autoConfiguration) {
-    autoConfiguration.addSpanExporterCustomizer(
-        (spanExporter, configProperties) ->
-            ElasticUserAgentHeader.configureIfPossible(spanExporter));
-    autoConfiguration.addMetricExporterCustomizer(
-        (metricExporter, configProperties) ->
-            ElasticUserAgentHeader.configureIfPossible(metricExporter));
-    autoConfiguration.addLogRecordExporterCustomizer(
-        (logExporter, configProperties) -> ElasticUserAgentHeader.configureIfPossible(logExporter));
-  }
-
-  private static void configureBlockableExporters(AutoConfigurationCustomizer autoConfiguration) {
-    autoConfiguration.addMetricExporterCustomizer(
-        (metricexporter, configProperties) ->
-            BlockableMetricExporter.createCustomInstance(metricexporter));
-    autoConfiguration.addSpanExporterCustomizer(
-        (spanExporter, configProperties) ->
-            BlockableSpanExporter.createCustomInstance(spanExporter));
-    autoConfiguration.addLogRecordExporterCustomizer(
-        (logExporter, configProperties) ->
-            BlockableLogRecordExporter.createCustomInstance(logExporter));
-  }
-
   static Map<String, String> propertiesCustomizer(ConfigProperties configProperties) {
     Map<String, String> config = new HashMap<>();
 

custom/src/main/java/co/elastic/otel/ElasticVerifyServerCert.java

@@ -0,0 +1,187 @@
+/*
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. 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 co.elastic.otel;
+
+import io.opentelemetry.exporter.otlp.http.logs.OtlpHttpLogRecordExporter;
+import io.opentelemetry.exporter.otlp.http.metrics.OtlpHttpMetricExporter;
+import io.opentelemetry.exporter.otlp.http.trace.OtlpHttpSpanExporter;
+import io.opentelemetry.exporter.otlp.logs.OtlpGrpcLogRecordExporter;
+import io.opentelemetry.exporter.otlp.metrics.OtlpGrpcMetricExporter;
+import io.opentelemetry.exporter.otlp.trace.OtlpGrpcSpanExporter;
+import io.opentelemetry.sdk.autoconfigure.spi.ConfigProperties;
+import io.opentelemetry.sdk.logs.export.LogRecordExporter;
+import io.opentelemetry.sdk.metrics.export.MetricExporter;
+import io.opentelemetry.sdk.trace.export.SpanExporter;
+import java.io.IOException;
+import java.io.InputStream;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.security.GeneralSecurityException;
+import java.security.KeyManagementException;
+import java.security.KeyStore;
+import java.security.NoSuchAlgorithmException;
+import java.security.cert.X509Certificate;
+import java.util.Properties;
+import javax.annotation.Nullable;
+import javax.net.ssl.KeyManager;
+import javax.net.ssl.KeyManagerFactory;
+import javax.net.ssl.SSLContext;
+import javax.net.ssl.TrustManager;
+import javax.net.ssl.X509TrustManager;
+
+public class ElasticVerifyServerCert {
+
+  private static final X509TrustManager X_509_TRUST_ALL =
+      new X509TrustManager() {
+        @Override
+        public void checkClientTrusted(X509Certificate[] chain, String authType) {}
+
+        @Override
+        public void checkServerTrusted(X509Certificate[] chain, String authType) {}
+
+        @Override
+        public X509Certificate[] getAcceptedIssuers() {
+          return new X509Certificate[0];
+        }
+      };
+
+  // package protected for testing
+  static boolean verifyServerCertificate(ConfigProperties config) {
+    return config.getBoolean("elastic.otel.verify.server.cert", true);
+  }
+
+  public static SpanExporter configureIfPossible(
+      SpanExporter spanExporter, ConfigProperties config) {
+    if (verifyServerCertificate(config)) {
+      return spanExporter;
+    }
+    if (spanExporter instanceof OtlpGrpcSpanExporter) {
+      return ((OtlpGrpcSpanExporter) spanExporter)
+          .toBuilder().setSslContext(getSslContext(), X_509_TRUST_ALL).build();
+    } else if (spanExporter instanceof OtlpHttpSpanExporter) {
+      return ((OtlpHttpSpanExporter) spanExporter)
+          .toBuilder().setSslContext(getSslContext(), X_509_TRUST_ALL).build();
+    }
+    return spanExporter;
+  }
+
+  public static MetricExporter configureIfPossible(
+      MetricExporter metricExporter, ConfigProperties config) {
+    if (verifyServerCertificate(config)) {
+      return metricExporter;
+    }
+    if (metricExporter instanceof OtlpGrpcMetricExporter) {
+      return ((OtlpGrpcMetricExporter) metricExporter)
+          .toBuilder().setSslContext(getSslContext(), X_509_TRUST_ALL).build();
+    } else if (metricExporter instanceof OtlpHttpMetricExporter) {
+      return ((OtlpHttpMetricExporter) metricExporter)
+          .toBuilder().setSslContext(getSslContext(), X_509_TRUST_ALL).build();
+    }
+    return metricExporter;
+  }
+
+  public static LogRecordExporter configureIfPossible(
+      LogRecordExporter logExporter, ConfigProperties config) {
+    if (verifyServerCertificate(config)) {
+      return logExporter;
+    }
+    if (logExporter instanceof OtlpGrpcLogRecordExporter) {
+      return ((OtlpGrpcLogRecordExporter) logExporter)
+          .toBuilder().setSslContext(getSslContext(), X_509_TRUST_ALL).build();
+    } else if (logExporter instanceof OtlpHttpLogRecordExporter) {
+      return ((OtlpHttpLogRecordExporter) logExporter)
+          .toBuilder().setSslContext(getSslContext(), X_509_TRUST_ALL).build();
+    }
+    return logExporter;
+  }
+
+  private static SSLContext getSslContext() {
+    SSLContext sslContext;
+    try {
+      sslContext = SSLContext.getInstance("TLS");
+    } catch (NoSuchAlgorithmException e) {
+      throw new IllegalStateException("Unable to create SSL/TLS context", e);
+    }
+
+    KeyManager[] keyManagers = null;
+    try {
+      keyManagers = getKeyManagers(System.getProperties());
+    } catch (IOException | GeneralSecurityException e) {
+      // silently ignored
+      // trust and key stores won't be available, which means client certificate can't be used
+    }
+
+    try {
+      sslContext.init(
+          keyManagers, new TrustManager[] {X_509_TRUST_ALL}, new java.security.SecureRandom());
+    } catch (KeyManagementException e) {
+      throw new IllegalStateException("unable to initialize SSL/TLS context", e);
+    }
+
+    return sslContext;
+  }
+
+  @Nullable
+  static KeyManager[] getKeyManagers(Properties properties)
+      throws IOException, GeneralSecurityException {
+    // re-implements parts of sun.security.ssl.SSLContextImpl.DefaultManagersHolder.getKeyManagers
+    // as there is no simple way to reuse existing implementation
+
+    String path = properties.getProperty("javax.net.ssl.keyStore");
+    String pwd = properties.getProperty("javax.net.ssl.keyStorePassword");
+    String type = properties.getProperty("javax.net.ssl.keyStoreType");
+    String provider = properties.getProperty("javax.net.ssl.keyStoreProvider");
+
+    KeyStore ks = null;
+    try {
+      if (path != null) {
+        ks = getKeyStore(Paths.get(path), pwd, type, provider);
+      }
+    } catch (IOException | GeneralSecurityException e) {
+      // silently ignore, client certificate won't work
+    }
+
+    KeyManagerFactory kmf = KeyManagerFactory.getInstance(KeyManagerFactory.getDefaultAlgorithm());
+    kmf.init(ks, pwd != null ? pwd.toCharArray() : null);
+    return kmf.getKeyManagers();
+  }
+
+  // package private for testing
+  @Nullable
+  static KeyStore getKeyStore(
+      Path keyStore,
+      @Nullable String keyStorePassword,
+      @Nullable String keyStoreType,
+      @Nullable String keyStoreProvider)
+      throws IOException, GeneralSecurityException {
+    String type = keyStoreType != null ? keyStoreType : KeyStore.getDefaultType();
+    if (keyStore == null) {
+      return null;
+    }
+    try (InputStream input = Files.newInputStream(keyStore)) {
+      KeyStore ks =
+          keyStoreProvider == null
+              ? KeyStore.getInstance(type)
+              : KeyStore.getInstance(type, keyStoreProvider);
+      ks.load(input, keyStorePassword != null ? keyStorePassword.toCharArray() : null);
+      return ks;
+    }
+  }
+}