以编程方式从PEM获取KeyStore

Question

如何以编程方式从同时包含证书和私钥的PEM文件中获取KeyStore？我正在尝试向HTTPS连接中的服务器提供客户端证书。我已经确认，如果我使用openssl和keytool来获得一个动态加载的jks文件，客户端证书就可以正常工作。我甚至可以通过动态读入一个p12 (PKCS12)文件来让它工作。

我正在考虑使用BouncyCastle中的PEMReader类，但我无法克服一些错误。我使用-Djavax.net.debug=all选项运行Java客户端，使用调试LogLevel运行Apache web服务器。不过，我不确定要找什么。Apache错误日志表明：

...
OpenSSL: Write: SSLv3 read client certificate B
OpenSSL: Exit: error in SSLv3 read client certificate B
Re-negotiation handshake failed: Not accepted by client!?

Java客户端程序指示：

...
main, WRITE: TLSv1 Handshake, length = 48
main, waiting for close_notify or alert: state 3
main, Exception while waiting for close java.net.SocketException: Software caused connection abort: recv failed
main, handling exception: java.net.SocketException: Software caused connection abort: recv failed
%% Invalidated:  [Session-3, TLS_RSA_WITH_AES_128_CBC_SHA]
main, SEND TLSv1 ALERT:  fatal, description = unexpected_message
...

客户端代码：

public void testClientCertPEM() throws Exception {
    String requestURL = "https://mydomain/authtest";
    String pemPath = "C:/Users/myusername/Desktop/client.pem";

    HttpsURLConnection con;

    URL url = new URL(requestURL);
    con = (HttpsURLConnection) url.openConnection();
    con.setSSLSocketFactory(getSocketFactoryFromPEM(pemPath));
    con.setRequestMethod("GET");
    con.setDoInput(true);
    con.setDoOutput(false);  
    con.connect();

    String line;

    BufferedReader reader = new BufferedReader(new InputStreamReader(con.getInputStream()));

    while((line = reader.readLine()) != null) {
        System.out.println(line);
    }       

    reader.close();
    con.disconnect();
}

public SSLSocketFactory getSocketFactoryFromPEM(String pemPath) throws Exception {
    Security.addProvider(new BouncyCastleProvider());        
    SSLContext context = SSLContext.getInstance("TLS");

    PEMReader reader = new PEMReader(new FileReader(pemPath));
    X509Certificate cert = (X509Certificate) reader.readObject();        

    KeyStore keystore = KeyStore.getInstance("JKS");
    keystore.load(null);
    keystore.setCertificateEntry("alias", cert);

    KeyManagerFactory kmf = KeyManagerFactory.getInstance("SunX509");
    kmf.init(keystore, null);

    KeyManager[] km = kmf.getKeyManagers(); 

    context.init(km, null, null);

    return context.getSocketFactory();
} 

我注意到服务器正在输出日志中的SSLv3，而客户端是TLSv1。如果我添加了系统属性-Dhttps.protocols=SSLv3，那么客户端也将使用SSLv3，但我得到了相同的错误消息。我还尝试在不改变结果的情况下添加-Dsun.security.ssl.allowUnsafeRenegotiation=true。

我已经用谷歌搜索过了，这个问题的通常答案是先使用openssl和keytool。在我的情况下，我需要在运行时直接读取PEM。实际上，我正在移植一个已经可以做到这一点的C++程序，坦率地说，我很惊讶在Java语言中做这件事有多么困难。C++代码：

  curlpp::Easy request;
  ...
  request.setOpt(new Options::Url(myurl));
  request.setOpt(new Options::SslVerifyPeer(false));
  request.setOpt(new Options::SslCertType("PEM"));
  request.setOpt(new Options::SslCert(cert));
  request.perform();

Answer 1

我想通了。问题是X509Certificate本身是不够的。我还需要将私钥放入动态生成的密钥库中。BouncyCastle PEMReader似乎不能同时处理包含证书和私钥的PEM文件，但它可以分别处理每个部分。我可以自己将PEM读入内存，并将其分成两个单独的流，然后将每个流提供给一个单独的PEMReader。因为我知道我正在处理的PEM文件将首先拥有证书，其次是私钥，所以我可以以健壮性为代价来简化代码。我还知道末尾证书分隔符总是用五个连字符括起来。对我有效的实现是：

protected static SSLSocketFactory getSocketFactoryPEM(String pemPath) throws Exception {        
    Security.addProvider(new BouncyCastleProvider());

    SSLContext context = SSLContext.getInstance("TLS");

    byte[] certAndKey = fileToBytes(new File(pemPath));

    String delimiter = "-----END CERTIFICATE-----";
    String[] tokens = new String(certAndKey).split(delimiter);

    byte[] certBytes = tokens[0].concat(delimiter).getBytes();
    byte[] keyBytes = tokens[1].getBytes();

    PEMReader reader;

    reader = new PEMReader(new InputStreamReader(new ByteArrayInputStream(certBytes)));
    X509Certificate cert = (X509Certificate)reader.readObject();        

    reader = new PEMReader(new InputStreamReader(new ByteArrayInputStream(keyBytes)));
    PrivateKey key = (PrivateKey)reader.readObject();        

    KeyStore keystore = KeyStore.getInstance("JKS");
    keystore.load(null);
    keystore.setCertificateEntry("cert-alias", cert);
    keystore.setKeyEntry("key-alias", key, "changeit".toCharArray(), new Certificate[] {cert});

    KeyManagerFactory kmf = KeyManagerFactory.getInstance("SunX509");
    kmf.init(keystore, "changeit".toCharArray());

    KeyManager[] km = kmf.getKeyManagers(); 

    context.init(km, null, null);

    return context.getSocketFactory();
}

更新：这似乎可以在没有BouncyCastle的情况下完成：

    byte[] certAndKey = fileToBytes(new File(pemPath));
    byte[] certBytes = parseDERFromPEM(certAndKey, "-----BEGIN CERTIFICATE-----", "-----END CERTIFICATE-----");
    byte[] keyBytes = parseDERFromPEM(certAndKey, "-----BEGIN PRIVATE KEY-----", "-----END PRIVATE KEY-----");

    X509Certificate cert = generateCertificateFromDER(certBytes);              
    RSAPrivateKey key  = generatePrivateKeyFromDER(keyBytes);

..。

protected static byte[] parseDERFromPEM(byte[] pem, String beginDelimiter, String endDelimiter) {
    String data = new String(pem);
    String[] tokens = data.split(beginDelimiter);
    tokens = tokens[1].split(endDelimiter);
    return DatatypeConverter.parseBase64Binary(tokens[0]);        
}

protected static RSAPrivateKey generatePrivateKeyFromDER(byte[] keyBytes) throws InvalidKeySpecException, NoSuchAlgorithmException {
    PKCS8EncodedKeySpec spec = new PKCS8EncodedKeySpec(keyBytes);

    KeyFactory factory = KeyFactory.getInstance("RSA");

    return (RSAPrivateKey)factory.generatePrivate(spec);        
}

protected static X509Certificate generateCertificateFromDER(byte[] certBytes) throws CertificateException {
    CertificateFactory factory = CertificateFactory.getInstance("X.509");

    return (X509Certificate)factory.generateCertificate(new ByteArrayInputStream(certBytes));      
}

Answer 2

虽然Ryan的回答效果很好，但我想为其他开发人员提供一个替代方案，因为我在过去也遇到过类似的挑战，我还需要处理pem格式的加密私钥。我已经创建了一个库来简化加载pem文件和从中创建SSLSocketFactory或SSLContext的过程，请参阅此处：GitHub - SSLContext Kickstart希望您喜欢:)

可以使用以下代码片段加载pem文件：

var keyManager = PemUtils.loadIdentityMaterial("certificate-chain.pem", "private-key.pem");
var trustManager = PemUtils.loadTrustMaterial("some-trusted-certificate.pem");

var sslFactory = SSLFactory.builder()
          .withIdentityMaterial(keyManager)
          .withTrustMaterial(trustManager)
          .build();

var sslContext = sslFactory.getSslContext();
var sslSocketFactory = sslFactory.getSslSocketFactory();

回到您的主要问题，使用上面的代码片段，不需要从pem文件创建keystore对象。它将在幕后处理这一点，并将其映射到一个KeyManager实例。