SSLEngine + NIO 实现SSL握手协议
Java 提供了阻塞和非阻塞I/O。非阻塞的I/O,大大提高了服务器的扩展性和伸缩性。
SSLServerSocket和SSLSocket是阻塞的socket调用。这连个类分别继承自ServerSocket和Socket, 封装了SSL(Secure Socket Layer)和TLS(Transport Layer Security), 提供了安全套接字。ServerSocket和Socket是阻塞的现实， 因此SSLServerSocket和SSLSocket也是阻塞的实现。阻塞实现的套接字的好处的是编程简单，学习成本低；缺点是扩展性和并发性较差。没法满足大并发服务器的实现要求。
如果要实现非阻塞的安全套接字，需要将SSLEngine和SocketChannel结合使用。
安全通信模型包括：
1）数据一致性保护。数据一致性通过加密套件和信息摘要套件实现
2）认证。Client和Server互相认证
3）机密性。 数据被加密后传输，没有明文数据（plain text）在网络上传播。
SSLEngine负责入栈和出栈数据加密和解密以及加密解密算法的协商。加密解密的算法是通过握手协议协商完成的。
握手过程如下：
1. 客户端想服务器端发送信息。信息包括支持的最高版本的SSL和加密套件列表。
2. 服务器发送支持的SSL和加密套件。完成加密套件的协商。
3.服务器端生成密钥并用公钥加密发送给服务器，服务器用私钥解密。
4.客户端和服务器用第三步生成的密钥加密数据进行传输
客户端代码如下：
package com.net;
import java.io.IOException;
import java.io.InputStream;
import java.net.InetSocketAddress;
import java.net.Authenticator.RequestorType;
import java.nio.ByteBuffer;
import java.nio.channels.SelectionKey;
import java.nio.channels.Selector;
import java.nio.channels.SocketChannel;
import java.security.KeyStore;
import java.util.Iterator;
import java.util.Scanner;
import java.util.logging.Logger;
import javax.net.ssl.SSLContext;
import javax.net.ssl.SSLEngine;
import javax.net.ssl.SSLEngineResult;
import javax.net.ssl.SSLException;
import javax.net.ssl.SSLSession;
import javax.net.ssl.TrustManagerFactory;
import javax.net.ssl.SSLEngineResult.HandshakeStatus;
import javax.net.ssl.SSLEngineResult.Status;
public class SSLHandshakeClient {
?? ?
??? private static Logger logger = Logger.getLogger(SSLHandshakeClient.class.getName());
?? ?
??? private SocketChannel sc;
?? ?
??? private SSLEngine sslEngine;
??? private Selector selector;
?? ?
??? private HandshakeStatus hsStatus;
??? private Status status;
?? ?
??? private ByteBuffer myNetData;
??? private ByteBuffer myAppData;
??? private ByteBuffer peerNetData;
??? private ByteBuffer peerAppData;
?? ?
??? private ByteBuffer dummy = ByteBuffer.allocate(0);
?? ?
??? public void run() throws Exception{
?????? ?
??????? char[] password = "123456".toCharArray();
??????? KeyStore trustStore = KeyStore.getInstance("JKS");
??????? InputStream in = this.getClass().getResourceAsStream("clienttruststore.jks");
??????? trustStore.load(in,password);
??????? TrustManagerFactory tmf = TrustManagerFactory.getInstance("SunX509");
??????? tmf.init(trustStore);
??????? SSLContext sslContext = SSLContext.getInstance("SSL");
??????? sslContext.init(null, tmf.getTrustManagers(), null);
??????? sslEngine = sslContext.createSSLEngine();
??????? sslEngine.setUseClientMode(true);
?????? ?
??????? SSLSession session = sslEngine.getSession();
??????? myAppData = ByteBuffer.allocate(session.getApplicationBufferSize());
??????? myNetData = ByteBuffer.allocate(session.getPacketBufferSize());
??????? peerAppData = ByteBuffer.allocate(session.getApplicationBufferSize());
??????? peerNetData = ByteBuffer.allocate(session.getPacketBufferSize());
?????? ?
??????? peerNetData.clear();
??????? SocketChannel channel = SocketChannel.open();
??????? channel.configureBlocking(false);
??????? selector = Selector.open();
??????? channel.register(selector, SelectionKey.OP_CONNECT);
??????? channel.connect(new InetSocketAddress("localhost", 443));
?????? ?
??????? sslEngine.beginHandshake();
??????? hsStatus = sslEngine.getHandshakeStatus();
?????? ?
??????? while(true){
?????????? ?
??????????? selector.select();
??????????? Iterator<SelectionKey> it = selector.selectedKeys().iterator();
??????????? while (it.hasNext()) {
??????????????? SelectionKey selectionKey = it.next();
??????????????? it.remove();
??????????????? handleSocketEvent(selectionKey);
??????????? }
??????? }
??? }
?? ?
??? private void handleSocketEvent(SelectionKey key) throws IOException{
?????? ?
??????? if(key.isConnectable()){
??????????? sc = (SocketChannel)key.channel();
??????????? if(sc.isConnectionPending()){
??????????????? sc.finishConnect();
??????????? }
?????????? ?
??????????? doHandshake();
?????????? ?
??????????? sc.register(selector, SelectionKey.OP_READ);
?????????? ?
??????? }
?????? ?
??????? if(key.isReadable()){
?????????? ?
??????????? sc = (SocketChannel)key.channel();
?????????? ?
??????????? doHandshake();
?????????? ?
??????????? if(hsStatus == HandshakeStatus.FINISHED){
??????????????? logger.info("Client handshake completes... ...");
??????????????? key.cancel();
??????????????? sc.close();
??????????? }
?????????? ?
??????? }
?????? ?
??? }
?? ?
??? private void doHandshake() throws IOException{
?????? ?
??????? SSLEngineResult result;
??????? int count = 0;
?? ?
??????? while(hsStatus != HandshakeStatus.FINISHED){
?????????? ?
??????????? logger.info("handshake status: " + hsStatus);
??????????? switch (hsStatus) {
??????????? case NEED_TASK:
??????????????? Runnable runnable;
??????????????? while((runnable=sslEngine.getDelegatedTask()) != null){
??????????????????? runnable.run();
??????????????? }
??????????????? hsStatus = sslEngine.getHandshakeStatus();
??????????????? break;
?????????????? ?
??????????? case NEED_UNWRAP:
?????????????? ?
??????????????? count = sc.read(peerNetData);
??????????????? if(count < 0){
??????????????????? logger.info("no data is read for unwrap.");
??????????????????? break;
??????????????? }else{
??????????????????? logger.info("data read: " + count);
??????????????? }
??????????????? peerNetData.flip();
??????????????? peerAppData.clear();
?????????????? ?
??????????????? do {
??????????????????? result = sslEngine.unwrap(peerNetData, peerAppData);
??????????????????? logger.info("Unwrapping:\n" + result);
??????????????????? // During an handshake renegotiation we might need to perform
??????????????????? // several unwraps to consume the handshake data.
??????????????? } while (result.getStatus() == SSLEngineResult.Status.OK &&
??????????????????????? result.getHandshakeStatus() == SSLEngineResult.HandshakeStatus.NEED_UNWRAP &&
??????????????????????? result.bytesProduced() == 0);
?????????????? ?
??????????????? if (peerAppData.position() == 0 &&
??????????????????? result.getStatus() == SSLEngineResult.Status.OK &&
??????????????????? peerNetData.hasRemaining())
??????????????? {
?????????????????????? ?
??????????????????? result = sslEngine.unwrap(peerNetData, peerAppData);
??????????????????? logger.info("Unwrapping:\n" + result);
?????????????????????? ?
??????????????? }
?????????????? ?
??????????????? hsStatus = result.getHandshakeStatus();
??????????????? status = result.getStatus();
?????????????? ?
??????????????? assert status != status.BUFFER_OVERFLOW : "buffer not overflow." + status.toString();
?????????????? ?
??????????????? // Prepare the buffer to be written again.
??????????????? peerNetData.compact();
??????????????? // And the app buffer to be read.
??????????????? peerAppData.flip();
?????????????? ?
??????????????? break;
?????????????? ?
??????????? case NEED_WRAP:
?????????????? ?
??????????????? myNetData.clear();
??????????????? result = sslEngine.wrap(dummy, myNetData);
??????????????? hsStatus = result.getHandshakeStatus();
??????????????? status = result.getStatus();
?????????????? ?
??????????????? while (status != Status.OK) {
??????????????????? logger.info("status: " + status);
??????????????????? switch (status) {
?????????????????? ?
??????????????????? case BUFFER_OVERFLOW:
??????????????????????? break;
?????????????????? ?
??????????????????? case BUFFER_UNDERFLOW:
?????????????????? ?
??????????????????????? break;
??????????????????? }
?????????????????? ?
??????????????? }
??????????????? myNetData.flip();
??????????????? count = sc.write(myNetData);
??????????????? if(count <=0){
??????????????????? logger.info("No data is written.");
??????????????? }else{
??????????????????? logger.info("Written data: " + count);
??????????????? }
?????????????? ?
??????????????? break;
?????????????? ?
??????????? }
??????? }
??? }
??? public static void main(String[] args) throws Exception {
??????? new SSLHandshakeClient().run();
??? }
?? ?
?? ?
}
服务器代码：
package com.net;
import java.io.IOException;
import java.io.InputStream;
import java.net.InetSocketAddress;
import java.net.ServerSocket;
import java.nio.ByteBuffer;
import java.nio.channels.SelectionKey;
import java.nio.channels.Selector;
import java.nio.channels.ServerSocketChannel;
import java.nio.channels.SocketChannel;
import java.security.KeyStore;
import java.util.Iterator;
import java.util.logging.Logger;
import javax.net.ssl.KeyManagerFactory;
import javax.net.ssl.SSLContext;
import javax.net.ssl.SSLEngine;
import javax.net.ssl.SSLEngineResult;
import javax.net.ssl.SSLSession;
import javax.net.ssl.SSLEngineResult.HandshakeStatus;
import javax.net.ssl.SSLEngineResult.Status;
public class SSLHandshakeServer {
?? ?
??? private static Logger logger = Logger.getLogger(SSLHandshakeServer.class.getName());
?? ?
??? private SocketChannel sc;
??? private SSLEngine sslEngine;
??? private Selector selector;
?? ?
??? private ByteBuffer myNetData;
??? private ByteBuffer myAppData;
??? private ByteBuffer peerNetData;
??? private ByteBuffer peerAppData;
?? ?
??? private ByteBuffer dummy = ByteBuffer.allocate(0);
?? ?
??? private HandshakeStatus hsStatus;
??? private Status status;
?? ?
??? public void run() throws Exception{
?????? ?
??????? char[] password = "123456".toCharArray();
??????? KeyStore keyStore = KeyStore.getInstance("JKS");
??????? InputStream in = this.getClass().getResourceAsStream("serverkeystore");
??????? keyStore.load(in, password);
??????? KeyManagerFactory kmf = KeyManagerFactory.getInstance("SunX509");
??????? kmf.init(keyStore, password);
??????? SSLContext sslContext = SSLContext.getInstance("SSL");
??????? sslContext.init(kmf.getKeyManagers(), null, null);
??????? sslEngine = sslContext.createSSLEngine();
??????? sslEngine.setUseClientMode(false);
?????? ?
??????? SSLSession session = sslEngine.getSession();
??????? myAppData = ByteBuffer.allocate(session.getApplicationBufferSize());
??????? myNetData = ByteBuffer.allocate(session.getPacketBufferSize());
??????? peerAppData = ByteBuffer.allocate(session.getApplicationBufferSize());
??????? peerNetData = ByteBuffer.allocate(session.getPacketBufferSize());
?????? ?
??????? peerNetData.clear();
?????? ?
??????? ServerSocketChannel serverChannel = ServerSocketChannel.open();
??????? serverChannel.configureBlocking(false);
??????? selector = Selector.open();
??????? ServerSocket serverSocket = serverChannel.socket();
??????? serverSocket.bind(new InetSocketAddress(443));
??????? serverChannel.register(selector, SelectionKey.OP_ACCEPT);
?? ?
??????? logger.info("Server listens on port 443... ...");
?????? ?
??????? while (true) {
??????????? selector.select();
??????????? Iterator<SelectionKey> it = selector.selectedKeys().iterator();
??????????? while (it.hasNext()) {
??????????????? SelectionKey selectionKey = it.next();
??????????????? it.remove();
??????????????? handleRequest(selectionKey);
??????????? }
??????? }
?????? ?
?????? ?
??? }
?? ?
??? private void handleRequest(SelectionKey key) throws Exception {
??????? if (key.isAcceptable()) {
??????????? ServerSocketChannel ssc = (ServerSocketChannel) key.channel();
??????????? SocketChannel channel = ssc.accept();
??????????? channel.configureBlocking(false);
??????????? channel.register(selector, SelectionKey.OP_READ);
??????? } else if (key.isReadable()) {
??????????? sc = (SocketChannel) key.channel();
?????????? ?
??????????? logger.info("Server handshake begins... ...");
??????????? sslEngine.beginHandshake();
??????????? hsStatus = sslEngine.getHandshakeStatus();
??????????? doHandshake();
??????????? if(hsStatus == HandshakeStatus.FINISHED){
??????????????? key.cancel();
??????????????? sc.close();
??????????? }
??????????? logger.info("Server handshake completes... ...");
?????????????? ?
??????? }
?????????? ?
??? }
?? ?
??? private void doHandshake() throws IOException{
?????? ?
??????? SSLEngineResult result;
?? ?
??????? while(hsStatus != HandshakeStatus.FINISHED){
?????????? ?
??????????? logger.info("handshake status: " + hsStatus);
??????????? switch (hsStatus) {
??????????? case NEED_TASK:
??????????????? Runnable runnable;
??????????????? while((runnable=sslEngine.getDelegatedTask()) != null){
??????????????????? runnable.run();
??????????????? }
??????????????? hsStatus = sslEngine.getHandshakeStatus();
??????????????? break;
?????????????? ?
??????????? case NEED_UNWRAP:
?????????????? ?
??????????????? int count = sc.read(peerNetData);
??????????????? if(count < 0){
??????????????????? logger.info("no data is read for unwrap.");
??????????????????? break;
??????????????? }else{
??????????????????? logger.info("data read: " + count);
??????????????? }
??????????????? peerNetData.flip();
??????????????? peerAppData.clear();
?????????????? ?
??????????????? do {
??????????????????? result = sslEngine.unwrap(peerNetData, peerAppData);
??????????????????? logger.info("Unwrapping:\n" + result);
??????????????????? // During an handshake renegotiation we might need to perform
??????????????????? // several unwraps to consume the handshake data.
??????????????? } while (result.getStatus() == SSLEngineResult.Status.OK &&
??????????????????????? result.getHandshakeStatus() == SSLEngineResult.HandshakeStatus.NEED_UNWRAP &&
??????????????????????? result.bytesProduced() == 0);
?????????????? ?
??????????????? if (peerAppData.position() == 0 &&
??????????????????? result.getStatus() == SSLEngineResult.Status.OK &&
??????????????????? peerNetData.hasRemaining())
??????????????? {
?????????????????????? ?
??????????????????? result = sslEngine.unwrap(peerNetData, peerAppData);
??????????????????? logger.info("Unwrapping:\n" + result);
?????????????????????? ?
??????????????? }
?????????????? ?
??????????????? hsStatus = result.getHandshakeStatus();
??????????????? status = result.getStatus();
?????????????? ?
??????????????? assert status != status.BUFFER_OVERFLOW : "buffer not overflow." + status.toString();
?????????????? ?
??????????????? // Prepare the buffer to be written again.
??????????????? peerNetData.compact();
??????????????? // And the app buffer to be read.
??????????????? peerAppData.flip();
?????????????? ?
??????????????? break;
?????????????? ?
??????????? case NEED_WRAP:
?????????????? ?
??????????????? myNetData.clear();
??????????????? result = sslEngine.wrap(dummy, myNetData);
??????????????? hsStatus = result.getHandshakeStatus();
??????????????? status = result.getStatus();
?????????????? ?
??????????????? while (status != Status.OK) {
??????????????????? logger.info("status: " + status);
??????????????????? switch (status) {
?????????????????? ?
??????????????????? case BUFFER_OVERFLOW:
??????????????????????? break;
?????????????????? ?
??????????????????? case BUFFER_UNDERFLOW:
?????????????????? ?
??????????????????????? break;
??????????????????? }
?????????????????? ?
??????????????? }
??????????????? myNetData.flip();
??????????????? sc.write(myNetData);
?????????????? ?
??????????????? break;
?????????????? ?
??????????? }
??????? }
??? }
?? ?
??? public static void main(String[] args) throws Exception {
??????? new SSLHandshakeServer().run();
??? }
?? ?
}
证书生成过程如下：
1. 生成keystore和自签名的certificate, 并生成相应公钥和私钥
%keytool -genkeypair -alias duke -keyalg RSA -validity 7 -keystore keystore?
Enter keystore password: password
What is your first and last name? [Unknown]: Duke
What is the name of your organizational unit? [Unknown]: Java Software
What is the name of your organization? [Unknown]: Sun Microsystems, Inc.
What is the name of your City or Locality? [Unknown]: Palo Alto
What is the name of your State or Province? [Unknown]: CA
What is the two-letter country code for this unit? [Unknown]: US
Is CN=Duke, OU=Java Software, O="Sun Microsystems, Inc.",
L=Palo Alto, ST=CA, C=US correct?
[no]: yes
Enter key password for <duke> (RETURN if same as keystore password): <CR>
2.查看keystore
%keytool -list -v -keystore keystore
Enter keystore password: password
Keystore type: jks
Keystore provider: SUN
Your keystore contains 1 entry
Alias name: duke
Creation date: Dec 20, 2001
Entry type: keyEntry
Certificate chain length: 1
Certificate[1]:
Owner: CN=Duke, OU=Java Software, O="Sun Microsystems, Inc.",L=Palo Alto, ST=CA, C=US
Issuer: CN=Duke, OU=Java Software, O="Sun Microsystems, Inc.", L=Palo Alto, ST=CA, C=US
Serial number: 3c22adc1
Valid from: Thu Dec 20 19:34:25 PST 2001 until: Thu Dec 27 19:34:25 PST 2001
Certificate fingerprints: MD5: F1:5B:9B:A1:F7:16:CF:25:CF:F4:FF:35:3F:4C:9C:F0
SHA1: B2:00:50:DD:B6:CC:35:66:21:45:0F:96:AA:AF:6A:3D:E4:03:7C:74
3. 导出证书
%keytool -export -alias duke -keystore keystore -rfc -file duke.cer
Enter keystore password: password
Certificate stored in file <duke.cer>
% cat duke.cer
-----BEGIN CERTIFICATE-----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
-----END CERTIFICATE-----
4. 将第三步导出的证书导入到一个truststore
% keytool -import -alias dukecert -file duke.cer -keystore truststore
Enter keystore password: trustword
Owner: CN=Duke, OU=Java Software, O="Sun Microsystems, Inc.", L=Palo Alto, ST=CA, C=US
Issuer: CN=Duke, OU=Java Software, O="Sun Microsystems, Inc.", L=Palo Alto, ST=CA, C=US
Serial number: 3c22adc1
Valid from: Thu Dec 20 19:34:25 PST 2001 until: Thu Dec 27 19:34:25 PST 2001
Certificate fingerprints:
MD5: F1:5B:9B:A1:F7:16:CF:25:CF:F4:FF:35:3F:4C:9C:F0
SHA1: B2:00:50:DD:B6:CC:35:66:21:45:0F:96:AA:AF:6A:3D:E4:03:7C:74
Trust this certificate? [no]: yes
Certificate was added to keystore
5. 检查 truststore
% keytool -list -v -keystore truststore
Enter keystore password: trustword
Keystore type: jks
Keystore provider: SUN
Your keystore contains 1 entry
Alias name: dukecert
Creation date: Dec 20, 2001
Entry type: trustedCertEntry
Owner: CN=Duke, OU=Java Software, O="Sun Microsystems, Inc.", L=Palo Alto, ST=CA, C=US
Issuer: CN=Duke, OU=Java Software, O="Sun Microsystems, Inc.", L=Palo Alto, ST=CA, C=USSerial number: 3c22adc1
Valid from: Thu Dec 20 19:34:25 PST 2001 until: Thu Dec 27 19:34:25 PST 2001
Certificate fingerprints:
MD5: F1:5B:9B:A1:F7:16:CF:25:CF:F4:FF:35:3F:4C:9C:F0
SHA1: B2:00:50:DD:B6:CC:35:66:21:45:0F:96:AA:AF:6A:3D:E4:03:7C:74
