如何使用 BouncyCastle 进行 TLS 操作？

这是一个非常基本的示例，具有仅服务器身份验证和自签名证书。该代码基于BC 1.49，主要是leightweight API：

ServerSocket serverSocket = new ServerSocket(SERVER_PORT);
final KeyPair keyPair = ...
final Certificate bcCert = new Certificate(new org.spongycastle.asn1.x509.Certificate[] {
    new X509V3CertificateStrategy().selfSignedCertificateHolder(keyPair).toASN1Structure()}); 
while (true) {
    Socket socket = serverSocket.accept();
    TlsServerProtocol tlsServerProtocol = new TlsServerProtocol(
    socket.getInputStream(), socket.getOutputStream(), secureRandom);
    tlsServerProtocol.accept(new DefaultTlsServer() {
        protected TlsSignerCredentials getRSASignerCredentials() throws IOException {
            return tlsSignerCredentials(context);
        }               
    });      
    new PrintStream(tlsServerProtocol.getOutputStream()).println("Hello TLS");
}

哪里

private TlsSignerCredentials tlsSignerCredentials(TlsContext context) throws IOException {
    return new DefaultTlsSignerCredentials(context, bcCert,
            PrivateKeyFactory.createKey(keyPair.getPrivate().getEncoded()));                
}

这是客户端代码：

Socket socket = new Socket(<server IP>, SERVER_PORT);
TlsClientProtocol tlsClientProtocol = new TlsClientProtocol(    
    socket.getInputStream(), socket.getOutputStream());
tlsClientProtocol.connect(new DefaultTlsClient() {          
    public TlsAuthentication getAuthentication() throws IOException {
        return new ServerOnlyTlsAuthentication() {                  
            public void notifyServerCertificate(Certificate serverCertificate) throws IOException {
                validateCertificate(serverCertificate);
            }
        };
    }
});
String message = new BufferedReader(
    new InputStreamReader(tlsClientProtocol.getInputStream())).readLine();

您需要使用来自 tlsClient/ServerProtocol 的输入和输出流来读取和写入加密数据（例如 tlsClientProtocol.getInputStream（））。否则，如果你使用例如 socket.getOutputStream（），你只会写入未加密的数据。

如何实施验证证书？我使用的是自签名证书。这意味着我只是在密钥库中查找它们，没有任何证书链。这是我创建密钥存储的方式：

KeyStore keyStore = KeyStore.getInstance(KeyStore.getDefaultType());
keyStore.load(null, password);
X509Certificate certificate = ...;
keyStore.setCertificateEntry(alias, certificate);

这是验证：

private void validateCertificate(org.spongycastle.crypto.tls.Certificate cert) throws IOException, CertificateException, KeyStoreException {
    byte[] encoded = cert.getCertificateList()[0].getEncoded();
    java.security.cert.Certificate jsCert = 
        CertificateFactory.getInstance("X.509").generateCertificate(new ByteArrayInputStream(encoded));
    String alias = keyStore.getCertificateAlias(jsCert);
    if(alias == null) {
        throw new IllegalArgumentException("Unknown cert " + jsCert);
    }
}

相当令人困惑的是三个不同的证书类。您必须在它们之间进行转换，如上所示。

场景：我们的生产服务器正在使用 JDK1.6。但是，客户服务器已升级为仅在 TLS 1.2 中进行通信。两个服务器之间的 SSL 通信已中断。但是我们不能简单地将JDK6升级到8（默认情况下支持TLS 1.2），因为这会导致其他库的兼容性问题。

下面的示例代码使用 jdk1.6.0_45 和 bcprov-jdk15on-153.jar（Bouncy Castle SIGNED JAR FILES）连接到使用 TLS 的任何服务器。

import java.io.IOException;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.Socket;

import org.bouncycastle.crypto.tls.CertificateRequest;
import org.bouncycastle.crypto.tls.DefaultTlsClient;
import org.bouncycastle.crypto.tls.TlsAuthentication;
import org.bouncycastle.crypto.tls.TlsClientProtocol;
import org.bouncycastle.crypto.tls.TlsCredentials;

public class TestHttpClient {
    // Reference: http://boredwookie.net/index.php/blog/how-to-use-bouncy-castle-lightweight-api-s-tlsclient/
    //            bcprov-jdk15on-153.tar\src\org\bouncycastle\crypto\tls\test\TlsClientTest.java
    public static void main(String[] args) throws Exception {
        java.security.SecureRandom secureRandom = new java.security.SecureRandom();
        Socket socket = new Socket(java.net.InetAddress.getByName("www.google.com"), 443);
        TlsClientProtocol protocol = new TlsClientProtocol(socket.getInputStream(), socket.getOutputStream(),secureRandom);
        DefaultTlsClient client = new DefaultTlsClient() {
            public TlsAuthentication getAuthentication() throws IOException {
                TlsAuthentication auth = new TlsAuthentication() {
                    // Capture the server certificate information!
                    public void notifyServerCertificate(org.bouncycastle.crypto.tls.Certificate serverCertificate) throws IOException {
                    }

                    public TlsCredentials getClientCredentials(CertificateRequest certificateRequest) throws IOException {
                        return null;
                    }
                };
                return auth;
            }
        };
        protocol.connect(client);

        java.io.OutputStream output = protocol.getOutputStream();
        output.write("GET / HTTP/1.1\r\n".getBytes("UTF-8"));
        output.write("Host: www.google.com\r\n".getBytes("UTF-8"));
        output.write("Connection: close\r\n".getBytes("UTF-8")); // So the server will close socket immediately.
        output.write("\r\n".getBytes("UTF-8")); // HTTP1.1 requirement: last line must be empty line.
        output.flush();

        java.io.InputStream input = protocol.getInputStream();
        BufferedReader reader = new BufferedReader(new InputStreamReader(input));
        String line;
        while ((line = reader.readLine()) != null)
        {
            System.out.println(line);
        }
    }
}

示例输出显示 JDK 6 可以获取 TLS 中的服务器页面，而不是某些 SSL 异常：

HTTP/1.1 302 Found
Cache-Control: private
Content-Type: text/html; charset=UTF-8
Location: https://www.google.com.sg/?gfe_rd=cr&ei=WRgeVovGEOTH8Afcx4XYAw
Content-Length: 263
Date: Wed, 14 Oct 2015 08:54:49 GMT
Server: GFE/2.0
Alternate-Protocol: 443:quic,p=1
Alt-Svc: quic="www.google.com:443"; p="1"; ma=600,quic=":443"; p="1"; ma=600
Connection: close

<HTML><HEAD><meta http-equiv="content-type" content="text/html;charset=utf-8">
<TITLE>302 Moved</TITLE></HEAD><BODY>
<H1>302 Moved</H1>
The document has moved
<A HREF="https://www.google.com.sg/?gfe_rd=cr&amp;ei=WRgeVovGEOTH8Afcx4XYAw">here</A>.
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