Java cipher加密与解密

r囧r小猫 2022-06-07 04:00 258阅读 0赞

**javax.crypto.Cipher类提供加密和解密功能，该类是JCE框架的核心。**  
ENCRYPT\_MODE,加密数据  
DECRYPT\_MODE,解密数据  
WRAP\_MODE,将一个Key封装成字节，可以用来进行安全传输  
UNWRAP\_MODE,将前述已封装的密钥解开成java.security.Key对象

import javax.crypto.Cipher;
    import javax.crypto.KeyGenerator;
    import java.security.Key;
    
    /** * @author someone * @create 2017-10-10 9:44 **/
    public class CipherUtil { 
        private String algorithm; // 算法，如DES
        private Key key; // 根据算法对应的密钥
        private String plainText; // 明文
    
        KeyGenerator keyGenerator;
        Cipher cipher;
    
        // 函数进行初始化
        CipherUtil(String alg, String msg) {
            algorithm = alg;
            plainText = msg;
        }
    
        // 加密函数，将原文加密成密文
        public byte[] encrypt() {
            byte[] cipherText = null;
    
            try {
                // 生成Cipher对象
                cipher = Cipher.getInstance(algorithm);
                // 用密钥加密明文(plainText),生成密文(cipherText)
                cipher.init(Cipher.ENCRYPT_MODE, key); // 操作模式为加密(Cipher.ENCRYPT_MODE),key为密钥
                cipherText = cipher.doFinal(plainText.getBytes()); // 得到加密后的字节数组
                // String str = new String(cipherText);
            } catch (Exception e) {
                e.printStackTrace();
            }
            return cipherText;
        }
    
        // 获取密钥包装成byte[]类型的
        public byte[] getBinaryKey(Key k) {
            byte[] bk = null;
            try {
                bk = cipher.wrap(k);
            } catch (Exception ex) {
                ex.printStackTrace();
            }
            return bk;
        }
    
        // 解密函数，将密文解密回原文
        public String decrypt(byte[] cipherText, Key k) {
            byte[] sourceText = null;
    
            try {
                cipher.init(Cipher.DECRYPT_MODE, k); // 操作模式为解密,key为密钥
                sourceText = cipher.doFinal(cipherText);
            } catch (Exception e) {
                e.printStackTrace();
            }
            return new String(sourceText);
    
        }
    
        // 生成密钥
        public Key keyGenerator() {
            try {
                // 初始化密钥key
                keyGenerator = KeyGenerator.getInstance(algorithm);
                keyGenerator.init(56); // 选择DES算法,密钥长度必须为56位
                key = keyGenerator.generateKey(); // 生成密钥
            } catch (Exception ex) {
                ex.printStackTrace();
            }
            return key;
        }
    
        public static void main(String[] args) {
            String algorithm = "DES"; // 定义加密算法,可用 DES,DESede,Blowfish
            String message = "Hello morning. 这是待加密的信息"; // 生成个DES密钥
            Key key;
    
            CipherUtil cm = new CipherUtil(algorithm, message);
            key = cm.keyGenerator();
            byte[] msg = cm.encrypt();
            System.out.println("加密后的密文为：" + new String(msg));
            //System.out.println(cm.getBinaryKey(key));
            System.out.println("解密密文为：" + cm.decrypt(msg, key));
    
        }
    
    }

参考：[http://www.cnblogs.com/langtianya/archive/2013/01/31/2883867.html][http_www.cnblogs.com_langtianya_archive_2013_01_31_2883867.html]

[http_www.cnblogs.com_langtianya_archive_2013_01_31_2883867.html]: http://www.cnblogs.com/langtianya/archive/2013/01/31/2883867.html