JAVA中使用RSA通过秘钥文件对字符串进行加密解密

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//字符串进行加密算法的名称
public static final String ALGORITHM = "RSA";
//字符串进行加密填充的名称
public static final String PADDING = "RSA/NONE/NoPadding";
//字符串持有安全提供者的名称
public static final String PROVIDER = "BC";
//私钥文件路径(RSAUtil是RSA工具类的类名)
public static final String PRIVATE_KEY_FILE = RSAUtil.class.getClassLoader().getResource("").getPath() + "key" + "private_response_key_1.key";
//公钥文件路径
public static final String PUBLIC_KEY_FILE = RSAUtil.class.getClassLoader().getResource("").getPath() + "key" + "public_request_key_1.key";
 
/**
* 测试加密解密
*/
public void rsaTest(String str) {
        log.info("[要加密解密的参数:{}]", str);
        try {
            String cipherText = encrypt(str);
            String plainText = decrypt(cipherText);
            log.info("[加密后的参数为:{}]", cipherText);
            log.info("[解密后的参数为:{}]", plainText);
        } catch (Exception e) {
            log.info("[RSA加密解密出现异常:{}]", e);
        }
}
 
/**
 * 将字符串进行RSA加密
 *
 * @param text
 * @return
 */
public static String encrypt(String text) {
    String cipherTextBase64 = "";
    try {
        ObjectInputStream inputStream = new ObjectInputStream(new FileInputStream(PUBLIC_KEY_FILE));
        PublicKey publicKey = (PublicKey) inputStream.readObject();
        Security.addProvider(new BouncyCastleProvider());
        Cipher cipher = Cipher.getInstance(PADDING, PROVIDER);
        cipher.init(Cipher.ENCRYPT_MODE, publicKey);
        byte[] cipherText = cipher.doFinal(text.getBytes());
        Base64 base64 = new Base64();
        cipherTextBase64 = base64.encodeToString(cipherText);
    } catch (Exception e) {
        log.info("[字符串进行RSA加密出现异常:{}]", e);
    }
    return cipherTextBase64;
}
/**
 * 将字符串进行RSA解密
 *
 * @param str
 * @return
 */
public static String decrypt(String str) {
    byte[] dectyptedText = null;
    try {
        ObjectInputStream inputStream = new ObjectInputStream(new FileInputStream(PRIVATE_KEY_FILE));
        PrivateKey privateKey = (PrivateKey) inputStream.readObject();
        Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());
        Cipher cipher = Cipher.getInstance(PADDING, PROVIDER);
        cipher.init(Cipher.DECRYPT_MODE, privateKey);
        Base64 base64 = new Base64();
        byte[] text = base64.decode(str);
        dectyptedText = cipher.doFinal(text);
    } catch (Exception e) {
        log.info("[字符串进行RSA解密出现异常:{}]", e);
    }
    return new String(dectyptedText);
}
/**
 * 判断秘钥文件是否存在
 *
 * @return
 */
public static boolean areKeysPresent() {
    File privateKey = new File(PRIVATE_KEY_FILE);
    File publicKey = new File(PUBLIC_KEY_FILE);
    if (privateKey.exists() && publicKey.exists()) {
        return true;
    }
    return false;
}
 
/**
 * 生成公钥文件和私钥文件
 */
public static void generateKey() {
    try {
        Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());
        final KeyPairGenerator keyGen = KeyPairGenerator.getInstance(ALGORITHM, PROVIDER);
        keyGen.initialize(1024);
        final KeyPair key = keyGen.generateKeyPair();
        File privateKeyFile = new File(PRIVATE_KEY_FILE);
        File publicKeyFile = new File(PUBLIC_KEY_FILE);
        if (privateKeyFile.getParentFile() != null) {
            privateKeyFile.getParentFile().mkdirs();
        }
        privateKeyFile.createNewFile();
        if (publicKeyFile.getParentFile() != null) {
            publicKeyFile.getParentFile().mkdirs();
        }
        publicKeyFile.createNewFile();
        ObjectOutputStream publicKeyOS = new ObjectOutputStream(new FileOutputStream(publicKeyFile));
        publicKeyOS.writeObject(key.getPublic());
        publicKeyOS.close();
        ObjectOutputStream privateKeyOS = new ObjectOutputStream(new FileOutputStream(privateKeyFile));
        privateKeyOS.writeObject(key.getPrivate());
        privateKeyOS.close();
    } catch (Exception e) {
        log.info("[生成公钥文件和私钥文件出现异常{}]", e);
    }
}