Java加密技术（十二）——*.PFX(*.p12)&个人信息交换文件

 

今天来点实际工作中的硬通货！ 
与计费系统打交道，少不了用到加密/解密实现。为了安全起见，通过非对称加密交换对称加密密钥更是不可或缺。那么需要通过什么载体传递非对称算法公钥/私钥信息？数字证书是公钥的载体，而密钥库可以包含公钥、私钥信息。 
JKS和PKCS#12都是比较常用的两种密钥库格式/标准。对于前者，搞Java开发，尤其是接触过HTTPS平台的朋友，并不陌生。JKS文件（通常为*.jks或*.keystore，扩展名无关）可以通过Java原生工具——KeyTool生成；而后者PKCS#12文件（通常为*.p12或*.pfx，意味个人信息交换文件），则是通过更为常用的OpenSSL工具产生。 
当然，这两者之间是可以通过导入/导出的方式进行转换的！当然，这种转换需要通过KeyTool工具进行！ 
回归正题，计费同事遇到一个难题：合作方交给他们一个*.pfx文件，需要他们从中提取密钥，然后进行加密交互。其实，通过Java直接操作密钥库文件（或个人信息交换文件）对于一般Java开发人员来说，这都是个冷门。不接触数字安全，根本不知所云。况且，Java原生的密钥库文件格式为JKS，如何操作*.pfx文件？密钥库操作需要获知密钥库别名，*.pfx别名是什么？！接下来就解决这些问题！ 

方案： 

1. 通过keytool密钥库导入命令importkeystore，将密钥库格式由PKCS#12转换为JKS。
2. 检索新生成的密钥库文件，提取别名信息。
3. 由密钥库文件导出数字证书（这里将用到别名）。
4. 通过代码提取公钥/私钥、签名算法等

先看格式转换： 

echo 格式转换
keytool -importkeystore -v  -srckeystore zlex.pfx -srcstoretype pkcs12 -srcstorepass 123456 -destkeystore zlex.keystore -deststoretype jks -deststorepass 123456

-importkeystore导入密钥库，通过格式设定，我们可以将PKCS#12文件转换为JKS格式。 
-v显示详情 
-srckeystore源密钥库，这里是zlex.pfx 
-srcstoretype源密钥库格式，这里为pkcs12 
-srcstorepass源密钥库密码，这里为123456 
-destkeystore目标密钥库，这里为zlex.keystore 
-deststoretype目标密钥库格式，这里为jks，默认值也如此 
-deststorepass目标密钥库密码，这里为123456 
通过这个操作，我们能够获得所需的密钥库文件zlex.keystore。 
 
这时，我们已经获得了密钥库文件，只要确定对应的别名信息，就可以提取公钥/私钥，以及数字证书，进行加密交互了！ 

echo 查看证书
keytool -list -keystore zlex.keystore -storepass 123456 -v

-list列举密钥库 
-keystore密钥库，这里是zlex.keystore 
-storepass密钥库密码，这里是123456 
-v显示详情 
 
这里需要细致观察一下别名信息！！！就是红框中的数字1！！！ 


现在，我们把证书导出！ 

echo 导出证书
keytool -exportcert -alias 1 -keystore zlex.keystore -file zlex.crt -storepass 123456

-exportcert导出证书 
-alias别名，这里是1 
-keystore密钥库，这里是zlex.keystore 
-file证书文件，这里是zlex.crt 
-storepass密钥库密码，这里是123456 
 
现在证书也导出了，我们可以提取公钥/私钥，进行加密/解密，签名/验证操作了！当然，即便没有证书，我们也能够通过密钥库（JKS格式）文件获得证书，以及公钥/私钥、签名算法等。 
补充代码， 其实就是对Java加密技术（八）的修改！ 

/**
 * 2010-8-11
 */

import java.io.FileInputStream;
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;

/**
 * 证书操作类
 *
 * @author <a href="mailto:[e-mail]">梁栋</a>
 * @since 1.0
 */
public class CertificateCoder {
    /**
     * 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 keyStorePassword
     * @param alias
     * @param aliasPassword
     * @return
     * @throws Exception
     */
    private static PrivateKey getPrivateKey(String keyStorePath,
            String keyStorePassword, String alias, String aliasPassword)
            throws Exception {
        KeyStore ks = getKeyStore(keyStorePath, keyStorePassword);
        PrivateKey key = (PrivateKey) ks.getKey(alias,
                aliasPassword.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 keyStorePassword
     * @param alias
     * @return
     * @throws Exception
     */
    private static Certificate getCertificate(String keyStorePath,
            String keyStorePassword, String alias) throws Exception {
        KeyStore ks = getKeyStore(keyStorePath, keyStorePassword);
        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 keyStorePassword
     * @param alias
     * @param aliasPassword
     * @return
     * @throws Exception
     */
    public static byte[] encryptByPrivateKey(byte[] data, String keyStorePath,
            String keyStorePassword, String alias, String aliasPassword)
            throws Exception {
        // 取得私钥
        PrivateKey privateKey = getPrivateKey(keyStorePath, keyStorePassword,
                alias, aliasPassword);

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

        // 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 keyStorePassword
     * @param aliasPassword
     * @return
     * @throws Exception
     */
    public static byte[] sign(byte[] sign, String keyStorePath, String alias,
            String keyStorePassword, String aliasPassword) throws Exception {
        // 获得证书
        X509Certificate x509Certificate = (X509Certificate) getCertificate(
                keyStorePath, keyStorePassword, alias);

        // 取得私钥
        PrivateKey privateKey = getPrivateKey(keyStorePath, keyStorePassword,
                alias, aliasPassword);

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

    /**
     * 验证签名
     *
     * @param data
     * @param sign
     * @param certificatePath
     * @return
     * @throws Exception
     */
    public static boolean verify(byte[] data, byte[] 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(sign);

    }

    /**
     * 验证Certificate
     *
     * @param keyStorePath
     * @param keyStorePassword
     * @param alias
     * @return
     */
    public static boolean verifyCertificate(Date date, String keyStorePath,
            String keyStorePassword, String alias) {
        boolean status = true;
        try {
            Certificate certificate = getCertificate(keyStorePath,
                    keyStorePassword, alias);
            status = verifyCertificate(date, certificate);
        } catch (Exception e) {
            status = false;
        }
        return status;
    }

    /**
     * 验证Certificate
     *
     * @param keyStorePath
     * @param keyStorePassword
     * @param alias
     * @return
     */
    public static boolean verifyCertificate(String keyStorePath,
            String keyStorePassword, String alias) {
        return verifyCertificate(new Date(), keyStorePath, keyStorePassword,
                alias);
    }
}

相信上述代码已经帮朋友们解决了相当多的问题！ 
给出测试类： 

import static org.junit.Assert.*;

import java.util.Date;

import org.apache.commons.codec.binary.Hex;
import org.junit.Test;

/**
 * 证书操作验证类
 *
 * @author <a href="mailto:[e-mail]">梁栋</a>
 * @version 1.0
 * @since 1.0
 */
public class CertificateCoderTest {
    private String certificatePath = "zlex.crt";
    private String keyStorePath = "zlex.keystore";
    private String keyStorePassword = "123456";
    private String aliasPassword = "123456";
    private String alias = "1";

    @Test
    public void test() throws Exception {
        System.err.println("公钥加密——私钥解密");
        String inputStr = "Ceritifcate";
        byte[] data = inputStr.getBytes();

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

        byte[] decrypt = CertificateCoder.decryptByPrivateKey(encrypt,
                keyStorePath, alias, keyStorePassword, aliasPassword);
        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));

    }

    @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 = CertificateCoder.encryptByPrivateKey(data,
                keyStorePath, keyStorePassword, alias, aliasPassword);

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

        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
        byte[] sign = CertificateCoder.sign(encodedData, keyStorePath, alias,
                keyStorePassword, aliasPassword);
        System.err.println("签名:\r" + Hex.encodeHexString(sign));

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

    @Test
    public void testVerify() throws Exception {
        System.err.println("密钥库证书有效期验证");
        boolean status = CertificateCoder.verifyCertificate(new Date(),
                keyStorePath, keyStorePassword, alias);
        System.err.println("证书状态:\r" + status);
        assertTrue(status);
    }
}

第一个测试方法，用于提取公钥/私钥进行加密/解密操作。 
第二个测试方法，用于提取签名算法进行签名/验证操作。 
第三个测试方法，用于测试密钥库该别名对应的证书，当前日期下，是否有效。 
 


OK，任务完成，密钥成功提取，剩下的都是代码基本功了！