基於數字證書的數據加密算法

package com.ice.webos.util.security;

import java.io.DataInputStream;
import java.io.FileInputStream;
import java.io.InputStream;
import java.net.URL;
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.util.Date;

import javax.crypto.Cipher;
import javax.net.ssl.HttpsURLConnection;
import javax.net.ssl.KeyManagerFactory;
import javax.net.ssl.SSLContext;
import javax.net.ssl.SSLSocketFactory;
import javax.net.ssl.TrustManagerFactory;

/**
 * 证书的制作,导入,删除
 * <ul>
 * <li>生成keyStroe文件</li>
 * <ul>
 * <li>keytool -genkey -validity 36000 -alias 192.168.20.230 -keyalg RSA
 * -keystore d:\zlex.keystore</li>
 * <ul>
 * 参数说明
 * <li>-genkey表示生成密钥</li>
 * <li>-validity指定证书有效期，这里是36000天</li>
 * <li>-alias指定别名，这里是192.168.20.230</li>
 * <li>-keyalg指定算法，这里是RSA</li>
 * <li>-keystore指定存储位置，这里是d:\zlex.keystore</li>
 * </ul>
 * </ul>
 * <li>生成自签名证书</li>
 * <ul>
 * <li>keytool -export -keystore d:\zlex.keystore -alias 192.168.20.230 -file
 * d:\zlex.cer -rfc</li>
 * <ul>
 * 参数说明
 * <li>-export指定为导出操作</li>
 * <li>-keystore指定keystore文件</li>
 * <li>-alias指定导出keystore文件中的别名</li>
 * <li>-file指向导出路径</li>
 * <li>-rfc以文本格式输出，也就是以BASE64编码输出 </li>
 * </ul>
 * </ul>
 * <li>证书导入到密钥库</li>
 * <ul>
 * <li>keytool -import -alias 192.168.20.230 -file d:/zlex.cer -keystore
 * d:/zlex.keystore</li>
 * <ul>
 * 参数说明
 * <li>-import表示导入</li>
 * <li>-alias指定别名，这里是192.168.20.230</li>
 * <li>-file指定算法，这里是d:/zlex.cer</li>
 * <li>-keystore指定存储位置，这里是d:/zlex.keystore </li>
 * </ul>
 * </ul>
 * <li>配置tomcat</li>
 * <ul>
 * <li>将zlex.keystore拷贝到tomcat的conf目录下</li>
 * <li>配置server.xml。将如下内容加入配置文件<br>
 * &lt;Connector SSLEnabled="true" URIEncoding="UTF-8" clientAuth="false"
 * keystoreFile="conf/zlex.keystore" keystorePass="654321" maxThreads="150"
 * port="443" protocol="HTTP/1.1" scheme="https" secure="true" sslProtocol="TLS" />
 * </li>
 * <li>clientAuth="false"测试阶段，置为false，正式使用时建议使用true</li>
 * <li>启动tomcat，访问https://192.168.20.230</li>
 * <li></li>
 * </ul>
 * <li>证书的删除</li>
 * <ul>
 * <li>命令行中输入 certmgr.msc</li>
 * <li>找到安装的证书,删除即可</li>
 * </ul>
 * </ul>
 * 
 * @author Ice_Liu
 * 
 */
public class Certificateutil {
    /**
     * Java密钥库(Java Key Store，JKS)KEY_STORE
*/
    public static final String KEY_STORE = "JKS";

    public static final String X509 = "X.509";
    public static final String SunX509 = "SunX509";
    public static final String SSL = "SSL";

    /**
     * 由 KeyStore获得私钥
     * 
     * @param keyStorePath
     * @param alias
     * @param password
     * @return
     * @throws Exception
*/
    private static PrivateKey getPrivateKey(String keyStorePath, String alias, String password)
            throws Exception {
        KeyStore ks = getKeyStore(keyStorePath, password);
        PrivateKey key = (PrivateKey) ks.getKey(alias, password.toCharArray());
        return key;
    }

    /**
     * 由 Certificate获得公钥
     * 
     * @param certificatePath
     * @return
     * @throws Exception
*/
    private static PublicKey getPublicKey(String certificatePath) throws Exception {
        Certificate certificate = getCertificate(certificatePath);
        PublicKey key = certificate.getPublicKey();
        return key;
    }

    /**
     * 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, password);
        Certificate certificate = ks.getCertificate(alias);

        return certificate;
    }

    /**
     * 获得KeyStore
     * 
     * @param keyStorePath
     * @param password
     * @return
     * @throws Exception
*/
    private static KeyStore getKeyStore(String keyStorePath, String password) throws Exception {
        FileInputStream is = new FileInputStream(keyStorePath);
        KeyStore ks = KeyStore.getInstance(KEY_STORE);
        ks.load(is, password.toCharArray());
        is.close();
        return ks;
    }

    /**
     * 私钥加密
     * 
     * @param data
     * @param keyStorePath
     * @param alias
     * @param password
     * @return
     * @throws Exception
*/
    public static byte[] encryptByPrivateKey(byte[] data, String keyStorePath, String alias,
            String password) throws Exception {
        // 取得私钥
        PrivateKey privateKey = getPrivateKey(keyStorePath, alias, password);

        // 对数据加密
        Cipher cipher = Cipher.getInstance(privateKey.getAlgorithm());
        cipher.init(Cipher.ENCRYPT_MODE, privateKey);

        return cipher.doFinal(data);

    }

    /**
     * 私钥解密
     * 
     * @param data
     * @param keyStorePath
     * @param alias
     * @param password
     * @return
     * @throws Exception
*/
    public static byte[] decryptByPrivateKey(byte[] data, String keyStorePath, String alias,
            String password) throws Exception {
        // 取得私钥
        PrivateKey privateKey = getPrivateKey(keyStorePath, alias, password);

        // 对数据加密
        Cipher cipher = Cipher.getInstance(privateKey.getAlgorithm());
        cipher.init(Cipher.DECRYPT_MODE, privateKey);

        return cipher.doFinal(data);

    }

    /**
     * 公钥加密
     * 
     * @param data
     * @param certificatePath
     * @return
     * @throws Exception
*/
    public static byte[] encryptByPublicKey(byte[] data, String certificatePath) throws Exception {

        // 取得公钥
        PublicKey publicKey = getPublicKey(certificatePath);
        // 对数据加密
        Cipher cipher = Cipher.getInstance(publicKey.getAlgorithm());
        cipher.init(Cipher.ENCRYPT_MODE, publicKey);

        return cipher.doFinal(data);

    }

    /**
     * 公钥解密
     * 
     * @param data
     * @param certificatePath
     * @return
     * @throws Exception
*/
    public static byte[] decryptByPublicKey(byte[] data, String certificatePath) throws Exception {
        // 取得公钥
        PublicKey publicKey = getPublicKey(certificatePath);

        // 对数据加密
        Cipher cipher = Cipher.getInstance(publicKey.getAlgorithm());
        cipher.init(Cipher.DECRYPT_MODE, publicKey);

        return cipher.doFinal(data);

    }

    /**
     * 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 alias
     * @param password
     * 
     * @return
     * @throws Exception
*/
    public static String sign(byte[] sign, String keyStorePath, String alias, String password)
            throws Exception {
        // 获得证书
        X509Certificate x509Certificate = (X509Certificate) getCertificate(keyStorePath, alias,
                password);
        // 获取私钥
        KeyStore ks = getKeyStore(keyStorePath, password);
        // 取得私钥
        PrivateKey privateKey = (PrivateKey) ks.getKey(alias, password.toCharArray());

        // 构建签名
        Signature signature = Signature.getInstance(x509Certificate.getSigAlgName());
        signature.initSign(privateKey);
        signature.update(sign);
        return CryptUtil.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(CryptUtil.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);
    }

    /**
     * 获得SSLSocektFactory
     * 
     * @param password
     *            密码
     * @param keyStorePath
     *            密钥库路径
     * 
     * @param trustKeyStorePath
     *            信任库路径
     * @return
     * @throws Exception
*/
    private static SSLSocketFactory getSSLSocketFactory(String password, String keyStorePath,
            String trustKeyStorePath) throws Exception {
        // 初始化密钥库
        KeyManagerFactory keyManagerFactory = KeyManagerFactory.getInstance(SunX509);
        KeyStore keyStore = getKeyStore(keyStorePath, password);
        keyManagerFactory.init(keyStore, password.toCharArray());

        // 初始化信任库
        TrustManagerFactory trustManagerFactory = TrustManagerFactory.getInstance(SunX509);
        KeyStore trustkeyStore = getKeyStore(trustKeyStorePath, password);
        trustManagerFactory.init(trustkeyStore);

        // 初始化SSL上下文
        SSLContext ctx = SSLContext.getInstance(SSL);
        ctx.init(keyManagerFactory.getKeyManagers(), trustManagerFactory.getTrustManagers(), null);
        SSLSocketFactory sf = ctx.getSocketFactory();

        return sf;
    }

    /**
     * 为 HttpsURLConnection配置SSLSocketFactory
     * 
     * @param conn
     *            HttpsURLConnection
     * @param password
     *            密码
     * @param keyStorePath
     *            密钥库路径
     * 
     * @param trustKeyStorePath
     *            信任库路径
     * @throws Exception
*/
    public static void configSSLSocketFactory(HttpsURLConnection conn, String password,
            String keyStorePath, String trustKeyStorePath) throws Exception {
        conn.setSSLSocketFactory(getSSLSocketFactory(password, keyStorePath, trustKeyStorePath));
    }

    /**
     * @param args
     * @throws Exception
*/
    public static void main(String[] args) throws Exception {
        String password = "123456";
        String alias = "192.168.20.230";
        String certificatePath = "d:/zlex.cer";
        String keyStorePath = "d:/zlex.keystore";
        String clientKeyStorePath = keyStorePath;//"d:/zlex-client.keystore";
        String clientPassword = "123456";

        System.err.println("公钥加密——私钥解密");
        String inputStr = "Ceritifcate";
        byte[] data = inputStr.getBytes();

        byte[] encrypt = Certificateutil.encryptByPublicKey(data, certificatePath);

        byte[] decrypt = Certificateutil
                .decryptByPrivateKey(encrypt, keyStorePath, alias, password);
        String outputStr = new String(decrypt);

        System.err.println("加密前: " + inputStr + "\n\r" + "解密后: " + outputStr);
        // 验证证书有效
        System.out.println("验证证书有效:" + Certificateutil.verifyCertificate(certificatePath));

        System.out.println("**********************************************");
        System.err.println("私钥加密——公钥解密");

        inputStr = "sign";
        data = inputStr.getBytes();

        byte[] encodedData = Certificateutil.encryptByPrivateKey(data, keyStorePath, alias,
                password);

        byte[] decodedData = Certificateutil.decryptByPublicKey(encodedData, certificatePath);

        outputStr = new String(decodedData);
        System.err.println("加密前: " + inputStr + "\n\r" + "解密后: " + outputStr);

        System.err.println("私钥签名——公钥验证签名");
        // 产生签名
        String sign = Certificateutil.sign(encodedData, keyStorePath, alias, password);
        System.err.println("签名:\r" + sign);

        // 验证签名
        boolean status = Certificateutil.verify(encodedData, sign, certificatePath);
        System.err.println("状态:\r" + status);

        System.out.println("*****************************************************");
        URL url = new URL("https://" + alias + ":18433/webos");
        HttpsURLConnection conn = (HttpsURLConnection) url.openConnection();

        conn.setDoInput(true);
        conn.setDoOutput(true);

        Certificateutil.configSSLSocketFactory(conn, clientPassword, clientKeyStorePath,
                clientKeyStorePath);

        InputStream is = conn.getInputStream();

        int length = conn.getContentLength();

        DataInputStream dis = new DataInputStream(is);
        data = new byte[length];
        dis.readFully(data);

        dis.close();
        System.err.println(new String(data));
        conn.disconnect();

    }
}

 取得私匙和公匙的方法：

        KeyStore.PrivateKeyEntry pkEntry = (KeyStore.PrivateKeyEntry) ks.getEntry("client", new KeyStore.PasswordProtection(password.toCharArray()));
        privateKey = pkEntry.getPrivateKey();
　　　publicKey = certificate.getPublicKey();

這種取法 私匙和公匙一定是成對的。

上邊代碼裏的取法，私匙和公匙 如果使用 特殊證書的情況下會不成對。