本篇的主要内容为Java证书体系的实现。
请大家在阅读本篇内容时先阅读
Java加密技术（四），预先了解RSA加密算法。
在构建Java代码实现前，我们需要完成证书的制作。
1.生成keyStroe文件
在命令行下执行以下命令：
Shell代码
keytool -genkey -alias tomcat -keyalg RSA -keystore d:\.keystore
keytool -genkey -alias tomcat -keyalg RSA -keystore d:\.keystore
其中
-genkey表示生成密钥
-alias指定别名，这里是tomcat
-keyalg指定算法，这里是RSA
-keystore指定存储位置，这里是d:\.keystore
在这里我使用的密码为
123456
控制台输出：
Console代码
输入keystore密码： 再次输入新密码: 您的名字与姓氏是什么？ [Unknown]： zlex 您的组织单位名称是什么？ [Unknown]： zlex 您的组织名称是什么？ [Unknown]： zlex 您所在的城市或区域名称是什么？ [Unknown]： BJ 您所在的州或省份名称是什么？ [Unknown]： BJ 该单位的两字母国家代码是什么 [Unknown]： CN CN=zlex, OU=zlex, O=zlex, L=BJ, ST=BJ, C=CN 正确吗？ [否]： Y 输入<tomcat>的主密码 （如果和 keystore 密码相同，按回车）： 再次输入新密码:
输入keystore密码：
再次输入新密码:
您的名字与姓氏是什么？
[Unknown]： zlex
您的组织单位名称是什么？
[Unknown]： zlex
您的组织名称是什么？
[Unknown]： zlex
您所在的城市或区域名称是什么？
[Unknown]： BJ
您所在的州或省份名称是什么？
[Unknown]： BJ
该单位的两字母国家代码是什么
[Unknown]： CN
CN=zlex, OU=zlex, O=zlex, L=BJ, ST=BJ, C=CN 正确吗？
[否]： Y
输入<tomcat>的主密码
（如果和 keystore 密码相同，按回车）：
再次输入新密码:
这时，在D盘下会生成一个.keystore的文件。
2.生成证书
光有keyStore文件是不够的，还需要证书文件，证书才是直接提供给外界使用的公钥凭证。
导出证书：
Shell代码
keytool -export -keystore d:\.keystore -alias tomcat -file d:\tomcat.cer
keytool -export -keystore d:\.keystore -alias tomcat -file d:\tomcat.cer
其中
-export指定为导出操作
-keystore指定keystore文件
-alias指定导出keystore文件中的别名
-file指向导出路径
这里的密码是
123456
控制台输出：
Console代码
输入keystore密码： 保存在文件中的认证 <d:\tomcat.cer>
输入keystore密码：
保存在文件中的认证 <d:\tomcat.cer>
当然，使用方是需要注册证书的！
Ok，准备工作完成，开始Java实现！
通过java代码实现如下：
Coder类见
Java加密技术（一）
Java代码
import java.io.FileInputStream;
import java.security.KeyFactory;
import java.security.KeyStore;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.Signature;
import java.security.cert.Certificate;
import java.security.cert.CertificateFactory;
import java.security.cert.X509Certificate;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
import java.util.Date;
public abstract class CertificateCoder
extends Coder {
public static final String KEY_STORE =
"JKS";
public static final String X509 =
"X.509";
public static String getPrivateKey(String keyStorePath, String alias, String password)
throws Exception { KeyStore ks = getKeyStore(keyStorePath, alias, password); PrivateKey key = (PrivateKey) ks.getKey(alias, password.toCharArray());
return encryptBASE64(key.getEncoded()); }
public static String getPublicKey(String certificatePath)
throws Exception { Certificate certificate = getCertificate(certificatePath); PublicKey key = certificate.getPublicKey();
return encryptBASE64(key.getEncoded()); }
private static Certificate getCertificate(String certificatePath)
throws Exception { CertificateFactory certificateFactory = CertificateFactory .getInstance(X509); FileInputStream in =
new FileInputStream(certificatePath); Certificate certificate = certificateFactory.generateCertificate(in); in.close();
return certificate; }
private static Certificate getCertificate(String keyStorePath, String alias, String password)
throws Exception { KeyStore ks = getKeyStore(keyStorePath, alias, password); Certificate certificate = ks.getCertificate(alias);
return certificate; }
private static KeyStore getKeyStore(String keyStorePath, String alias, String password)
throws Exception { FileInputStream is =
new FileInputStream(keyStorePath); KeyStore ks = KeyStore.getInstance(KEY_STORE); ks.load(is, password.toCharArray()); is.close();
return ks; }
public static boolean verifyCertificate(String certificatePath) {
return verifyCertificate(
new Date(), certificatePath); }
public static boolean verifyCertificate(Date date, String certificatePath) {
boolean status =
true;
try { Certificate certificate = getCertificate(certificatePath); status = verifyCertificate(date, certificate); }
catch (Exception e) { status =
false; }
return status; }
public static boolean verifyPublicKey(String publicKey, String certificatePath) {
boolean status =
true;
try { Certificate certificate = getCertificate(certificatePath);
byte[] keyBytes = decryptBASE64(publicKey); X509EncodedKeySpec x509KeySpec =
new X509EncodedKeySpec(keyBytes); KeyFactory keyFactory = KeyFactory.getInstance(certificate .getPublicKey().getAlgorithm()); PublicKey pubKey = keyFactory.generatePublic(x509KeySpec); certificate.verify(pubKey); }
catch (Exception e) { status =
false; }
return status; }
private static boolean verifyCertificate(Date date, Certificate certificate) {
boolean status =
true;
try { X509Certificate x509Certificate = (X509Certificate) certificate; x509Certificate.checkValidity(date); }
catch (Exception e) { status =
false; }
return status; }
public static String sign(
byte[] sign, String keyStorePath, String privateKey, String alias, String password)
throws Exception { X509Certificate x509Certificate = (X509Certificate) getCertificate( keyStorePath, alias, password);
byte[] keyBytes = decryptBASE64(privateKey); PKCS8EncodedKeySpec pkcs8KeySpec =
new PKCS8EncodedKeySpec(keyBytes); KeyFactory keyFactory = KeyFactory.getInstance(x509Certificate .getPublicKey().getAlgorithm()); PrivateKey priKey = keyFactory.generatePrivate(pkcs8KeySpec); Signature signature = Signature.getInstance(x509Certificate .getSigAlgName()); signature.initSign(priKey); signature.update(sign);
return encryptBASE64(signature.sign()); }
public static boolean verify(
byte[] data, String sign, String certificatePath)
throws Exception { X509Certificate x509Certificate = (X509Certificate) getCertificate(certificatePath); PublicKey publicKey = x509Certificate.getPublicKey(); Signature signature = Signature.getInstance(x509Certificate .getSigAlgName()); signature.initVerify(publicKey); signature.update(data);
return signature.verify(decryptBASE64(sign)); }
public static boolean verifyCertificate(Date date, String keyStorePath, String alias, String password) {
boolean status =
true;
try { Certificate certificate = getCertificate(keyStorePath, alias, password); status = verifyCertificate(date, certificate); }
catch (Exception e) { status =
false; }
return status; }
public static boolean verifyCertificate(String keyStorePath, String alias, String password) {
return verifyCertificate(
new Date(), keyStorePath, alias, password); } }
import java.io.FileInputStream;
import java.security.KeyFactory;
import java.security.KeyStore;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.Signature;
import java.security.cert.Certificate;
import java.security.cert.CertificateFactory;
import java.security.cert.X509Certificate;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
import java.util.Date;
/**
* 证书组件
*
* @author 梁栋
* @version 1.0
* @since 1.0
*/
public abstract class CertificateCoder extends Coder {
/**
* Java密钥库(Java Key Store，JKS)KEY_STORE
*/
public static final String KEY_STORE = "JKS";
public static final String X509 = "X.509";
/**
* 由KeyStore获得私钥
*
* @param keyStorePath
* @param alias
* @param password
* @return
* @throws Exception
*/
public static String getPrivateKey(String keyStorePath, String alias,
String password) throws Exception {
KeyStore ks = getKeyStore(keyStorePath, alias, password);
PrivateKey key = (PrivateKey) ks.getKey(alias, password.toCharArray());
return encryptBASE64(key.getEncoded());
}
/**
* 由Certificate获得公钥
*
* @param certificatePath
* @return
* @throws Exception
*/
public static String getPublicKey(String certificatePath) throws Exception {
Certificate certificate = getCertificate(certificatePath);
PublicKey key = certificate.getPublicKey();
return encryptBASE64(key.getEncoded());
}
/**
* 获得Certificate
*
* @param certificatePath
* @return
* @throws Exception
*/
private static Certificate getCertificate(String certificatePath)
throws Exception {
CertificateFactory certificateFactory = CertificateFactory
.getInstance(X509);
FileInputStream in = new FileInputStream(certificatePath);
Certificate certificate = certificateFactory.generateCertificate(in);
in.close();
return certificate;
}
/**
* 获得Certificate
*
* @param keyStorePath
* @param alias
* @param password
* @return
* @throws Exception
*/
private static Certificate getCertificate(String keyStorePath,
String alias, String password) throws Exception {
KeyStore ks = getKeyStore(keyStorePath, alias, password);
Certificate certificate = ks.getCertificate(alias);
return certificate;
}
/**
* 获得KeyStore
*
* @param keyStorePath
* @param alias
* @param password
* @return
* @throws Exception
*/
private static KeyStore getKeyStore(String keyStorePath, String alias,
String password) throws Exception {
FileInputStream is = new FileInputStream(keyStorePath);
KeyStore ks = KeyStore.getInstance(KEY_STORE);
ks.load(is, password.toCharArray());
is.close();
return ks;
}
/**
* 验证Certificate
*
* @param certificatePath
* @return
*/
public static boolean verifyCertificate(String certificatePath) {
return verifyCertificate(new Date(), certificatePath);
}
/**
* 验证Certificate是否过期或无效
*
* @param date
* @param certificatePath
* @return
*/
public static boolean verifyCertificate(Date date, String certificatePath) {
boolean status = true;
try {
// 取得证书
Certificate certificate = getCertificate(certificatePath);
// 验证证书是否过期或无效
status = verifyCertificate(date, certificate);
} catch (Exception e) {
status = false;
}
return status;
}
/**
* 验证公钥是否同属该证书
*
* @param publicKey
* @param certificatePath
* @return
*/
public static boolean verifyPublicKey(String publicKey,
String certificatePath) {
boolean status = true;
try {
Certificate certificate = getCertificate(certificatePath);
// 对公钥解密
byte[] keyBytes = decryptBASE64(publicKey);
// 取得公钥
X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(keyBytes);
KeyFactory keyFactory = KeyFactory.getInstance(certificate
.getPublicKey().getAlgorithm());
PublicKey pubKey = keyFactory.generatePublic(x509KeySpec);
certificate.verify(pubKey);
} catch (Exception e) {
status = false;
}
return status;
}
/**
* 验证证书是否过期或无效
*
* @param date
* @param certificate
* @return
*/
private static boolean verifyCertificate(Date date, Certificate certificate) {
boolean status = true;
try {
X509Certificate x509Certificate = (X509Certificate) certificate;
x509Certificate.checkValidity(date);
} catch (Exception e) {
status = false;
}
return status;
}
/**
* 签名
* @param keyStorePath
* @param privateKey
* @param alias
* @param password
* @return
* @throws Exception
*/
public static String sign(byte[] sign, String keyStorePath, String privateKey,
String alias, String password) throws Exception {
// 获得证书
X509Certificate x509Certificate = (X509Certificate) getCertificate(
keyStorePath, alias, password);
// 解密由base64编码的私钥
byte[] keyBytes = decryptBASE64(privateKey);
// 构造PKCS8EncodedKeySpec对象
PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);
// 由证书公钥获得对应加密算法
KeyFactory keyFactory = KeyFactory.getInstance(x509Certificate
.getPublicKey().getAlgorithm());
// 获取私钥
PrivateKey priKey = keyFactory.generatePrivate(pkcs8KeySpec);
// 构建签名
Signature signature = Signature.getInstance(x509Certificate
.getSigAlgName());
signature.initSign(priKey);
signature.update(sign);
return encryptBASE64(signature.sign());
}
/**
* 验证签名
*
* @param data
* @param sign
* @param certificatePath
* @return
* @throws Exception
*/
public static boolean verify(byte[] data, String sign,
String certificatePath) throws Exception {
// 获得证书
X509Certificate x509Certificate = (X509Certificate) getCertificate(certificatePath);
// 获得公钥
PublicKey publicKey = x509Certificate.getPublicKey();
// 构建签名
Signature signature = Signature.getInstance(x509Certificate
.getSigAlgName());
signature.initVerify(publicKey);
signature.update(data);
return signature.verify(decryptBASE64(sign));
}
/**
* 验证Certificate
*
* @param keyStorePath
* @param alias
* @param password
* @return
*/
public static boolean verifyCertificate(Date date, String keyStorePath,
String alias, String password) {
boolean status = true;
try {
Certificate certificate = getCertificate(keyStorePath, alias,
password);
status = verifyCertificate(date, certificate);
} catch (Exception e) {
status = false;
}
return status;
}
/**
* 验证Certificate
*
* @param keyStorePath
* @param alias
* @param password
* @return
*/
public static boolean verifyCertificate(String keyStorePath, String alias,
String password) {
return verifyCertificate(new Date(), keyStorePath, alias, password);
}
}
再给出一个测试类：
Java代码
import static org.junit.Assert.*;
import org.junit.Before;
import org.junit.Test;
public class CertificateCoderTest {
private String publicKey;
private String privateKey;
private String password =
"123456";
private String alias =
"tomcat";
private String certificatePath =
"D:/tomcat.cer";
private String keyStorePath =
"D:/.keystore";
@Before public void setUp()
throws Exception { publicKey = CertificateCoder.getPublicKey(certificatePath); privateKey = CertificateCoder.getPrivateKey(keyStorePath, alias, password); System.err.println(
"公钥: \n\r" + publicKey); System.err.println(
"私钥： \n\r" + privateKey); }
@Test public void test()
throws Exception { System.err.println(
"公钥加密——私钥解密"); String inputStr =
"Ceritificate";
byte[] data = inputStr.getBytes();
byte[] encrypt = RSACoder.encryptByPublicKey(data, publicKey);
byte[] decrypt = RSACoder.decryptByPrivateKey(encrypt, privateKey); String outputStr =
new String(decrypt); System.err.println(
"加密前: " + inputStr +
"\n\r" +
"解密后: " + outputStr); assertArrayEquals(data, decrypt); assertTrue(CertificateCoder.verifyCertificate(certificatePath)); assertTrue(CertificateCoder.verifyPublicKey(publicKey, certificatePath)); }
@Test public void testSign()
throws Exception { System.err.println(
"私钥加密——公钥解密"); String inputStr =
"sign";
byte[] data = inputStr.getBytes();
byte[] encodedData = RSACoder.encryptByPrivateKey(data, privateKey);
byte[] decodedData = RSACoder .decryptByPublicKey(encodedData, publicKey); String outputStr =
new String(decodedData); System.err.println(
"加密前: " + inputStr +
"\n\r" +
"解密后: " + outputStr); assertEquals(inputStr, outputStr); System.err.println(
"私钥签名——公钥验证签名"); String sign = CertificateCoder.sign(encodedData, keyStorePath, privateKey, alias, password); System.err.println(
"签名:\r" + sign);
boolean status = CertificateCoder.verify(encodedData, sign, certificatePath); System.err.println(
"状态:\r" + status); assertTrue(status); } }
import static org.junit.Assert.*;
import org.junit.Before;
import org.junit.Test;
/**
*
* @author 梁栋
* @version 1.0
* @since 1.0
*/
public class CertificateCoderTest {
private String publicKey;
private String privateKey;
private String password = "123456";
private String alias = "tomcat";
private String certificatePath = "D:/tomcat.cer";
private String keyStorePath = "D:/.keystore";
@Before
public void setUp() throws Exception {
publicKey = CertificateCoder.getPublicKey(certificatePath);
privateKey = CertificateCoder.getPrivateKey(keyStorePath, alias,
password);
System.err.println("公钥: \n\r" + publicKey);
System.err.println("私钥： \n\r" + privateKey);
}
@Test
public void test() throws Exception {
System.err.println("公钥加密——私钥解密");
String inputStr = "Ceritificate";
byte[] data = inputStr.getBytes();
byte[] encrypt = RSACoder.encryptByPublicKey(data, publicKey);
byte[] decrypt = RSACoder.decryptByPrivateKey(encrypt, privateKey);
String outputStr = new String(decrypt);
System.err.println("加密前: " + inputStr + "\n\r" + "解密后: " + outputStr);
// 验证数据一致
assertArrayEquals(data, decrypt);
// 验证证书有效
assertTrue(CertificateCoder.verifyCertificate(certificatePath));
// 验证证书公钥匹配
assertTrue(CertificateCoder.verifyPublicKey(publicKey, certificatePath));
}
@Test
public void testSign() throws Exception {
System.err.println("私钥加密——公钥解密");
String inputStr = "sign";
byte[] data = inputStr.getBytes();
byte[] encodedData = RSACoder.encryptByPrivateKey(data, privateKey);
byte[] decodedData = RSACoder
.decryptByPublicKey(encodedData, publicKey);
String outputStr = new String(decodedData);
System.err.println("加密前: " + inputStr + "\n\r" + "解密后: " + outputStr);
assertEquals(inputStr, outputStr);
System.err.println("私钥签名——公钥验证签名");
// 产生签名
String sign = CertificateCoder.sign(encodedData, keyStorePath, privateKey,
alias, password);
System.err.println("签名:\r" + sign);
// 验证签名
boolean status = CertificateCoder.verify(encodedData, sign, certificatePath);
System.err.println("状态:\r" + status);
assertTrue(status);
}
}
控制台输出：
Console代码
公钥: MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDBQ/VMxf5Sb+urKceu5Ja4GfxHso+i+CCpQV2c W/O0yyu6u//7emmbwQGV3BLvaq9hEav1yGdvBteITS+mKMQFr2vFMsxhs+Dh82haQF2CXm11KtOg 2cjN6zgRmPVdYndVjeq7I9z+lkyHYZsOFUGr+oiPcas2Y9fa07TEfM4LXwIDAQAB 私钥： MIICeAIBADANBgkqhkiG9w0BAQEFAASCAmIwggJeAgEAAoGBAMFD9UzF/lJv66spx67klrgZ/Eey j6L4IKlBXZxb87TLK7q7//t6aZvBAZXcEu9qr2ERq/XIZ28G14hNL6YoxAWva8UyzGGz4OHzaFpA XYJebXUq06DZyM3rOBGY9V1id1WN6rsj3P6WTIdhmw4VQav6iI9xqzZj19rTtMR8zgtfAgMBAAEC gYEAlB0y932d5SvlHy5L3JtPbxRrJb+RGUK0NULlLRnDckFq6BeAnQg5u6Z1QpaA5H+MnQXgFeNa cdp6f/k3lU4UuzgGbt0A31hRlR7J0WjsutkrDJp4h6PD9OIJSblv2T+h7KHzMKY7kx8dn4CIg2Cm 9NCyJWmhglGaf4Nl/6e4FdECQQD18SLbOxndmyHd5OU88oIY/qAyngQJIqcyHOwgwcLd5G/M3h0H bEj2fEKa4y2EG1xCH4MQSu0aRrR+ihv+thRjAkEAyStUwkyaNUE06ioGWCYu26QTcLyRwMyuVTcE jLbD6wRLF7A3gx9dgSV8mO1VqJ1G9y379YenzLz89MFHOTwn1QJBALNEcx3NtIrdexAcuiN0uPOz Fd4PY+2svqY+grdVxM6spfl0pUA14/EWng38Lb8vmk3wXj5P/we6JfJehQ1idvUCQQCTohkx/sWt D42ly/Gb/2mkB2W89qaAt7W5FAdivT5K23vAhrI2qG4WuUwXbxXOCJ5sCHNAXa3ns0pw1OdQObWB AkBm7JAy3jUh6xiEdI+SWnJ9V/k5bqenkN930uDFdqc6FzfOTgd3RVnckfpdCkEmo8AmeUQZwZ3y g4Xlfjray07N 公钥加密——私钥解密 加密前: Ceritificate 解密后: Ceritificate 公钥: MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDBQ/VMxf5Sb+urKceu5Ja4GfxHso+i+CCpQV2c W/O0yyu6u//7emmbwQGV3BLvaq9hEav1yGdvBteITS+mKMQFr2vFMsxhs+Dh82haQF2CXm11KtOg 2cjN6zgRmPVdYndVjeq7I9z+lkyHYZsOFUGr+oiPcas2Y9fa07TEfM4LXwIDAQAB 私钥： MIICeAIBADANBgkqhkiG9w0BAQEFAASCAmIwggJeAgEAAoGBAMFD9UzF/lJv66spx67klrgZ/Eey j6L4IKlBX
