我对HTTPS/SSL/TLS相当陌生,我有点困惑,当使用证书进行身份验证时,客户端究竟应该呈现什么。

I'm writing a Java client that needs to do a simple POST of data to a particular URL. That part works fine, the only problem is it's supposed to be done over HTTPS. The HTTPS part is fairly easy to handle (either with HTTPclient or using Java's built-in HTTPS support), but I'm stuck on authenticating with client certificates. I've noticed there's already a very similar question on here, which I haven't tried out with my code yet (will do so soon enough). My current issue is that - whatever I do - the Java client never sends along the certificate (I can check this with PCAP dumps).

我想知道客户端在使用证书进行身份验证时到底应该向服务器提供什么(特别是对于Java -如果这很重要的话)?这是一个JKS文件,还是PKCS#12?里面应该有什么;只有客户端证书,还是密钥?如果是,是哪个钥匙?关于所有不同类型的文件、证书类型等,有相当多的困惑。

正如我之前说过的,我是HTTPS/SSL/TLS的新手,所以我也希望能了解一些背景知识(不必是一篇文章;我将满足于好文章的链接)。


当前回答

JKS文件只是一个证书和密钥对的容器。 在客户端身份验证场景中,密钥的各个部分将位于这里:

客户端的存储区将包含客户端的私钥和公钥对。它称为密钥存储库。 服务器的存储区将包含客户端的公钥。它被称为信任库。

信任存储库和密钥存储库的分离不是强制的,但建议使用。它们可以是相同的物理文件。

要设置两个存储的文件系统位置,使用以下系统属性:

-Djavax.net.ssl.keyStore=clientsidestore.jks

在服务器端:

-Djavax.net.ssl.trustStore=serversidestore.jks

若要将客户端证书(公钥)导出到文件,以便将其复制到服务器,请使用

keytool -export -alias MYKEY -file publicclientkey.cer -store clientsidestore.jks

要将客户端的公钥导入到服务器的密钥存储库中,使用(正如海报中提到的,服务器管理员已经完成了这一操作)

keytool -import -file publicclientkey.cer -store serversidestore.jks

其他回答

最终解决了所有问题,所以我来回答我自己的问题。这些是我用来解决我的特定问题的设置/文件;

客户端的密钥存储库是一个PKCS#12格式文件,包含

客户端的公共证书(在本例中由自签名CA签名) 客户端的私钥

例如,我使用OpenSSL的pkcs12命令来生成它;

openssl pkcs12 -export -in client.crt -inkey client.key -out client.p12 -name "Whatever"

提示:确保你得到最新的OpenSSL,而不是0.9.8h版本,因为它似乎有一个错误,不允许你正确生成PKCS#12文件。

当服务器显式地请求客户端进行身份验证时,Java客户端将使用这个PKCS#12文件向服务器提供客户端证书。请参阅维基百科上关于TLS的文章,了解用于客户端证书身份验证的协议实际上是如何工作的(还解释了为什么这里需要客户端私钥)。

客户端的信任库是一个直接的JKS格式文件,其中包含根证书或中间CA证书。这些CA证书将决定允许您与哪些端点通信,在这种情况下,它将允许您的客户端连接到提供由信任存储库的CA之一签名的证书的任何服务器。

例如,你可以使用标准的Java keytool来生成它;

keytool -genkey -dname "cn=CLIENT" -alias truststorekey -keyalg RSA -keystore ./client-truststore.jks -keypass whatever -storepass whatever
keytool -import -keystore ./client-truststore.jks -file myca.crt -alias myca

使用这个信任库,您的客户端将尝试与所有提供由myca.crt标识的CA签名的证书的服务器进行一次完整的SSL握手。

上面的文件严格地只针对客户端。当您还想设置服务器时,服务器需要自己的密钥和信任库文件。在这个网站上可以找到关于为Java客户端和服务器(使用Tomcat)设置一个完全工作的示例的很好的演练。

问题/评论/建议

Client certificate authentication can only be enforced by the server. (Important!) When the server requests a client certificate (as part of the TLS handshake), it will also provide a list of trusted CA's as part of the certificate request. When the client certificate you wish to present for authentication is not signed by one of these CA's, it won't be presented at all (in my opinion, this is weird behaviour, but I'm sure there's a reason for it). This was the main cause of my issues, as the other party had not configured their server properly to accept my self-signed client certificate and we assumed that the problem was at my end for not properly providing the client certificate in the request. Get Wireshark. It has great SSL/HTTPS packet analysis and will be a tremendous help debugging and finding the problem. It's similar to -Djavax.net.debug=ssl but is more structured and (arguably) easier to interpret if you're uncomfortable with the Java SSL debug output. It's perfectly possible to use the Apache httpclient library. If you want to use httpclient, just replace the destination URL with the HTTPS equivalent and add the following JVM arguments (which are the same for any other client, regardless of the library you want to use to send/receive data over HTTP/HTTPS): -Djavax.net.debug=ssl -Djavax.net.ssl.keyStoreType=pkcs12 -Djavax.net.ssl.keyStore=client.p12 -Djavax.net.ssl.keyStorePassword=whatever -Djavax.net.ssl.trustStoreType=jks -Djavax.net.ssl.trustStore=client-truststore.jks -Djavax.net.ssl.trustStorePassword=whatever

JKS文件只是一个证书和密钥对的容器。 在客户端身份验证场景中,密钥的各个部分将位于这里:

客户端的存储区将包含客户端的私钥和公钥对。它称为密钥存储库。 服务器的存储区将包含客户端的公钥。它被称为信任库。

信任存储库和密钥存储库的分离不是强制的,但建议使用。它们可以是相同的物理文件。

要设置两个存储的文件系统位置,使用以下系统属性:

-Djavax.net.ssl.keyStore=clientsidestore.jks

在服务器端:

-Djavax.net.ssl.trustStore=serversidestore.jks

若要将客户端证书(公钥)导出到文件,以便将其复制到服务器,请使用

keytool -export -alias MYKEY -file publicclientkey.cer -store clientsidestore.jks

要将客户端的公钥导入到服务器的密钥存储库中,使用(正如海报中提到的,服务器管理员已经完成了这一操作)

keytool -import -file publicclientkey.cer -store serversidestore.jks

我认为这里的修复是密钥库类型,pkcs12(pfx)总是有私钥和JKS类型可以存在没有私钥。除非您在代码中指定或通过浏览器选择证书,否则服务器无法知道它在另一端代表客户端。

其他回答说明如何全局配置客户端证书。 然而,如果你想通过编程方式为一个特定的连接定义客户端密钥,而不是在JVM上运行的每个应用程序上全局定义它,那么你可以像这样配置自己的SSLContext:

String keyPassphrase = "";

KeyStore keyStore = KeyStore.getInstance("PKCS12");
keyStore.load(new FileInputStream("cert-key-pair.pfx"), keyPassphrase.toCharArray());

SSLContext sslContext = SSLContexts.custom()
        .loadKeyMaterial(keyStore, null)
        .build();

HttpClient httpClient = HttpClients.custom().setSSLContext(sslContext).build();
HttpResponse response = httpClient.execute(new HttpGet("https://example.com"));

有一种比手动导航到https://url更好的方法,知道在什么浏览器中单击哪个按钮,知道在哪里以及如何保存“证书”文件,最后知道keytool在本地安装它的神奇咒语。

只要这样做:

将下面的代码保存到InstallCert.java 打开命令行,执行:javac InstallCert.java 执行如下命令:java InstallCert <host>[:port] [passphrase] (port和passphrase是可选的)

下面是InstallCert的代码,注意头中的年份,将需要修改一些“后期”版本的java部分:

/*
 * Copyright 2006 Sun Microsystems, Inc.  All Rights Reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *   - Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *
 *   - Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution.
 *
 *   - Neither the name of Sun Microsystems nor the names of its
 *     contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

import java.io.*;
import java.net.URL;

import java.security.*;
import java.security.cert.*;

import javax.net.ssl.*;

public class InstallCert {

    public static void main(String[] args) throws Exception {
  String host;
  int port;
  char[] passphrase;
  if ((args.length == 1) || (args.length == 2)) {
      String[] c = args[0].split(":");
      host = c[0];
      port = (c.length == 1) ? 443 : Integer.parseInt(c[1]);
      String p = (args.length == 1) ? "changeit" : args[1];
      passphrase = p.toCharArray();
  } else {
      System.out.println("Usage: java InstallCert <host>[:port] [passphrase]");
      return;
  }

  File file = new File("jssecacerts");
  if (file.isFile() == false) {
      char SEP = File.separatorChar;
      File dir = new File(System.getProperty("java.home") + SEP
        + "lib" + SEP + "security");
      file = new File(dir, "jssecacerts");
      if (file.isFile() == false) {
    file = new File(dir, "cacerts");
      }
  }
  System.out.println("Loading KeyStore " + file + "...");
  InputStream in = new FileInputStream(file);
  KeyStore ks = KeyStore.getInstance(KeyStore.getDefaultType());
  ks.load(in, passphrase);
  in.close();

  SSLContext context = SSLContext.getInstance("TLS");
  TrustManagerFactory tmf =
      TrustManagerFactory.getInstance(TrustManagerFactory.getDefaultAlgorithm());
  tmf.init(ks);
  X509TrustManager defaultTrustManager = (X509TrustManager)tmf.getTrustManagers()[0];
  SavingTrustManager tm = new SavingTrustManager(defaultTrustManager);
  context.init(null, new TrustManager[] {tm}, null);
  SSLSocketFactory factory = context.getSocketFactory();

  System.out.println("Opening connection to " + host + ":" + port + "...");
  SSLSocket socket = (SSLSocket)factory.createSocket(host, port);
  socket.setSoTimeout(10000);
  try {
      System.out.println("Starting SSL handshake...");
      socket.startHandshake();
      socket.close();
      System.out.println();
      System.out.println("No errors, certificate is already trusted");
  } catch (SSLException e) {
      System.out.println();
      e.printStackTrace(System.out);
  }

  X509Certificate[] chain = tm.chain;
  if (chain == null) {
      System.out.println("Could not obtain server certificate chain");
      return;
  }

  BufferedReader reader =
    new BufferedReader(new InputStreamReader(System.in));

  System.out.println();
  System.out.println("Server sent " + chain.length + " certificate(s):");
  System.out.println();
  MessageDigest sha1 = MessageDigest.getInstance("SHA1");
  MessageDigest md5 = MessageDigest.getInstance("MD5");
  for (int i = 0; i < chain.length; i++) {
      X509Certificate cert = chain[i];
      System.out.println
        (" " + (i + 1) + " Subject " + cert.getSubjectDN());
      System.out.println("   Issuer  " + cert.getIssuerDN());
      sha1.update(cert.getEncoded());
      System.out.println("   sha1    " + toHexString(sha1.digest()));
      md5.update(cert.getEncoded());
      System.out.println("   md5     " + toHexString(md5.digest()));
      System.out.println();
  }

  System.out.println("Enter certificate to add to trusted keystore or 'q' to quit: [1]");
  String line = reader.readLine().trim();
  int k;
  try {
      k = (line.length() == 0) ? 0 : Integer.parseInt(line) - 1;
  } catch (NumberFormatException e) {
      System.out.println("KeyStore not changed");
      return;
  }

  X509Certificate cert = chain[k];
  String alias = host + "-" + (k + 1);
  ks.setCertificateEntry(alias, cert);

  OutputStream out = new FileOutputStream("jssecacerts");
  ks.store(out, passphrase);
  out.close();

  System.out.println();
  System.out.println(cert);
  System.out.println();
  System.out.println
    ("Added certificate to keystore 'jssecacerts' using alias '"
    + alias + "'");
    }

    private static final char[] HEXDIGITS = "0123456789abcdef".toCharArray();

    private static String toHexString(byte[] bytes) {
  StringBuilder sb = new StringBuilder(bytes.length * 3);
  for (int b : bytes) {
      b &= 0xff;
      sb.append(HEXDIGITS[b >> 4]);
      sb.append(HEXDIGITS[b & 15]);
      sb.append(' ');
  }
  return sb.toString();
    }

    private static class SavingTrustManager implements X509TrustManager {

  private final X509TrustManager tm;
  private X509Certificate[] chain;

  SavingTrustManager(X509TrustManager tm) {
      this.tm = tm;
  }

  public X509Certificate[] getAcceptedIssuers() {
      throw new UnsupportedOperationException();
  }

  public void checkClientTrusted(X509Certificate[] chain, String authType)
    throws CertificateException {
      throw new UnsupportedOperationException();
  }

  public void checkServerTrusted(X509Certificate[] chain, String authType)
    throws CertificateException {
      this.chain = chain;
      tm.checkServerTrusted(chain, authType);
  }
    }

}