我正在用Java编写一个应用程序，通过HTTPS连接到两个Web服务器。其中一个使用默认信任链的证书，另一个使用自签名证书。当然，直接连接到第一个服务器可以正常工作，而连接到具有自签名证书的服务器直到我创建了包含该服务器证书的trustStore之后才能正常工作。然而，一旦我创建了自己的trustStore，就无法再与默认信任的服务器建立连接，因为显然默认的trustStore被忽略了。
我找到的一个解决方案是将默认trustStore中的证书添加到我的trustStore中。然而，我不喜欢这种解决方案，因为它要求我继续管理该trustStore。（我不能假设这些证书在可预见的未来保持静态，对吗？）
此外，我发现了两个类似问题的5年前的线程：
它们都深入探讨了Java SSL基础设施。我希望现在有更方便的解决方案，我可以在我的代码安全审查中轻松解释。
TrustManagerFactory tmf = TrustManagerFactory
.getInstance(TrustManagerFactory.getDefaultAlgorithm());
// Using null here initialises the TMF with the default trust store.
tmf.init((KeyStore) null);
// Get hold of the default trust manager
X509TrustManager defaultTm = null;
for (TrustManager tm : tmf.getTrustManagers()) {
if (tm instanceof X509TrustManager) {
defaultTm = (X509TrustManager) tm;
break;
}
}
FileInputStream myKeys = new FileInputStream("truststore.jks");
// Do the same with your trust store this time
// Adapt how you load the keystore to your needs
KeyStore myTrustStore = KeyStore.getInstance(KeyStore.getDefaultType());
myTrustStore.load(myKeys, "password".toCharArray());
myKeys.close();
tmf = TrustManagerFactory
.getInstance(TrustManagerFactory.getDefaultAlgorithm());
tmf.init(myTrustStore);
// Get hold of the default trust manager
X509TrustManager myTm = null;
for (TrustManager tm : tmf.getTrustManagers()) {
if (tm instanceof X509TrustManager) {
myTm = (X509TrustManager) tm;
break;
}
}
// Wrap it in your own class.
final X509TrustManager finalDefaultTm = defaultTm;
final X509TrustManager finalMyTm = myTm;
X509TrustManager customTm = new X509TrustManager() {
@Override
public X509Certificate[] getAcceptedIssuers() {
// If you're planning to use client-cert auth,
// merge results from "defaultTm" and "myTm".
return finalDefaultTm.getAcceptedIssuers();
}
@Override
public void checkServerTrusted(X509Certificate[] chain,
String authType) throws CertificateException {
try {
finalMyTm.checkServerTrusted(chain, authType);
} catch (CertificateException e) {
// This will throw another CertificateException if this fails too.
finalDefaultTm.checkServerTrusted(chain, authType);
}
}
@Override
public void checkClientTrusted(X509Certificate[] chain,
String authType) throws CertificateException {
// If you're planning to use client-cert auth,
// do the same as checking the server.
finalDefaultTm.checkClientTrusted(chain, authType);
}
};
SSLContext sslContext = SSLContext.getInstance("TLS");
sslContext.init(null, new TrustManager[] { customTm }, null);
// You don't have to set this as the default context,
// it depends on the library you're using.
SSLContext.setDefault(sslContext);
原则上，您总是需要根据需要更新信任存储。Java 7 JSSE参考指南中有一个“重要说明”，现在在同一指南的8版中已降级为{{link1：“说明”}}:
JDK在java-home/lib/security/cacerts文件中提供了有限数量的受信任根证书。如keytool参考页面所述，如果您使用此文件作为信任存储，则有责任维护（即添加和删除）此文件中包含的证书。
根据您联系的服务器的证书配置，您可能需要添加其他根证书。从相应的供应商获取所需特定的根证书。
sslcontext-kickstart 是一个方便的库，它提供了包装器，可以通过一个简单的构建器实现这一点，该构建器可以拥有多个信任库，包括系统信任库。https://github.com/Hakky54/sslcontext-kickstart - eckesimport nl.altindag.ssl.SSLFactory;
import javax.net.ssl.SSLContext;
import java.security.cert.X509Certificate;
import java.nio.file.Path;
import java.util.List;
public class App {
public static void main(String[] args) {
Path trustStorePath = ...;
char[] password = "password".toCharArray();
SSLFactory sslFactory = SSLFactory.builder()
.withDefaultTrustMaterial() // JDK trusted CA's
.withSystemTrustMaterial() // OS trusted CA's
.withTrustMaterial(trustStorePath, password)
.build();
SSLContext sslContext = sslFactory.getSslContext();
List<X509Certificate> trustedCertificates = sslFactory.getTrustedCertificates();
}
}
<dependency>
<groupId>io.github.hakky54</groupId>
<artifactId>sslcontext-kickstart</artifactId>
<version>8.1.5</version>
</dependency>
通过调用 TrustManagerFactory.init((KeyStore)null)并获取其X509Certificates，您可以检索默认信任存储。将其与您自己的证书结合使用。您可以使用 KeyStore.load 从 .jks 或 .p12 文件中加载自签名证书，也可以通过CertificateFactory加载.crt（或.cer）文件。
以下是说明这一点的一些演示代码。如果您使用浏览器从stackoverflow.com下载证书，则可以运行该代码。如果注释掉加载的证书和默认证书，则代码将获得 SSLHandshakeException ，但是如果保留其中一个，它将返回状态码200。
import javax.net.ssl.*;
import java.io.*;
import java.net.URL;
import java.security.*;
import java.security.cert.*;
public class HttpsWithCustomCertificateDemo {
public static void main(String[] args) throws Exception {
// Create a new trust store, use getDefaultType for .jks files or "pkcs12" for .p12 files
KeyStore trustStore = KeyStore.getInstance(KeyStore.getDefaultType());
// Create a new trust store, use getDefaultType for .jks files or "pkcs12" for .p12 files
trustStore.load(null, null);
// If you comment out the following, the request will fail
trustStore.setCertificateEntry(
"stackoverflow",
// To test, download the certificate from stackoverflow.com with your browser
loadCertificate(new File("stackoverflow.crt"))
);
// Uncomment to following to add the installed certificates to the keystore as well
//addDefaultRootCaCertificates(trustStore);
SSLSocketFactory sslSocketFactory = createSslSocketFactory(trustStore);
URL url = new URL("https://stackoverflow.com/");
HttpsURLConnection conn = (HttpsURLConnection) url.openConnection();
// Alternatively, to use the sslSocketFactory for all Http requests, uncomment
//HttpsURLConnection.setDefaultSSLSocketFactory(sslSocketFactory);
conn.setSSLSocketFactory(sslSocketFactory);
System.out.println(conn.getResponseCode());
}
private static SSLSocketFactory createSslSocketFactory(KeyStore trustStore) throws GeneralSecurityException {
TrustManagerFactory tmf = TrustManagerFactory.getInstance(TrustManagerFactory.getDefaultAlgorithm());
tmf.init(trustStore);
TrustManager[] trustManagers = tmf.getTrustManagers();
SSLContext sslContext = SSLContext.getInstance("SSL");
sslContext.init(null, trustManagers, null);
return sslContext.getSocketFactory();
}
private static X509Certificate loadCertificate(File certificateFile) throws IOException, CertificateException {
try (FileInputStream inputStream = new FileInputStream(certificateFile)) {
return (X509Certificate) CertificateFactory.getInstance("X509").generateCertificate(inputStream);
}
}
private static void addDefaultRootCaCertificates(KeyStore trustStore) throws GeneralSecurityException {
TrustManagerFactory trustManagerFactory = TrustManagerFactory.getInstance(TrustManagerFactory.getDefaultAlgorithm());
// Loads default Root CA certificates (generally, from JAVA_HOME/lib/cacerts)
trustManagerFactory.init((KeyStore)null);
for (TrustManager trustManager : trustManagerFactory.getTrustManagers()) {
if (trustManager instanceof X509TrustManager) {
for (X509Certificate acceptedIssuer : ((X509TrustManager) trustManager).getAcceptedIssuers()) {
trustStore.setCertificateEntry(acceptedIssuer.getSubjectDN().getName(), acceptedIssuer);
}
}
}
}
}
load(null, null)。虽然看起来很奇怪，但它是必要的，因为它初始化了密钥库。 - Johannes Brodwall这里是Bruno答案的更简洁版（来源）
public void configureTrustStore() throws NoSuchAlgorithmException, KeyManagementException, KeyStoreException,
CertificateException, IOException {
X509TrustManager jreTrustManager = getJreTrustManager();
X509TrustManager myTrustManager = getMyTrustManager();
X509TrustManager mergedTrustManager = createMergedTrustManager(jreTrustManager, myTrustManager);
setSystemTrustManager(mergedTrustManager);
}
private X509TrustManager getJreTrustManager() throws NoSuchAlgorithmException, KeyStoreException {
return findDefaultTrustManager(null);
}
private X509TrustManager getMyTrustManager() throws FileNotFoundException, KeyStoreException, IOException,
NoSuchAlgorithmException, CertificateException {
// Adapt to load your keystore
try (FileInputStream myKeys = new FileInputStream("truststore.jks")) {
KeyStore myTrustStore = KeyStore.getInstance("jks");
myTrustStore.load(myKeys, "password".toCharArray());
return findDefaultTrustManager(myTrustStore);
}
}
private X509TrustManager findDefaultTrustManager(KeyStore keyStore)
throws NoSuchAlgorithmException, KeyStoreException {
TrustManagerFactory tmf = TrustManagerFactory.getInstance(TrustManagerFactory.getDefaultAlgorithm());
tmf.init(keyStore); // If keyStore is null, tmf will be initialized with the default trust store
for (TrustManager tm : tmf.getTrustManagers()) {
if (tm instanceof X509TrustManager) {
return (X509TrustManager) tm;
}
}
return null;
}
private X509TrustManager createMergedTrustManager(X509TrustManager jreTrustManager,
X509TrustManager customTrustManager) {
return new X509TrustManager() {
@Override
public X509Certificate[] getAcceptedIssuers() {
// If you're planning to use client-cert auth,
// merge results from "defaultTm" and "myTm".
return jreTrustManager.getAcceptedIssuers();
}
@Override
public void checkServerTrusted(X509Certificate[] chain, String authType) throws CertificateException {
try {
customTrustManager.checkServerTrusted(chain, authType);
} catch (CertificateException e) {
// This will throw another CertificateException if this fails too.
jreTrustManager.checkServerTrusted(chain, authType);
}
}
@Override
public void checkClientTrusted(X509Certificate[] chain, String authType) throws CertificateException {
// If you're planning to use client-cert auth,
// do the same as checking the server.
jreTrustManager.checkClientTrusted(chain, authType);
}
};
}
private void setSystemTrustManager(X509TrustManager mergedTrustManager)
throws NoSuchAlgorithmException, KeyManagementException {
SSLContext sslContext = SSLContext.getInstance("TLS");
sslContext.init(null, new TrustManager[] { mergedTrustManager }, null);
// You don't have to set this as the default context,
// it depends on the library you're using.
SSLContext.setDefault(sslContext);
}
我发现，你也可以使用Apache HttpComponents库中的SSLContextBuilder类将自定义密钥库添加到SSLContext中：
SSLContextBuilder builder = new SSLContextBuilder();
try {
keyStore.load(null, null);
builder.loadTrustMaterial(keyStore, null);
builder.loadKeyMaterial(keyStore, null);
} catch (NoSuchAlgorithmException | KeyStoreException | CertificateException | IOException
| UnrecoverableKeyException e) {
log.error("Can not load keys from keystore '{}'", keyStore.getProvider(), e);
}
return builder.build();
SSLContextBuilder#loadTrustMaterial 可用于加载一个信任存储。另一个方法 SSLContextBuilder#loadKeyMaterial 不是用于信任存储，而是用于密钥库，其目的不同。难道不是这样吗？ - ramtechloadTrustMaterial会做什么。至少在Java11的实现中，列表将被替换为给定的列表。
如果你反编译sun.security.provider.JavaKeyStore#engineLoad，你会看到this.entries.clear();。 - mohsen Lzd