Java DES对称加密工具类

秒速五厘米 2022-12-22 00:46 134阅读 0赞

DESUtil.java

import org.apache.tomcat.util.codec.binary.Base64;
    import java.io.FileInputStream;
    import java.io.FileNotFoundException;
    import java.io.FileOutputStream;
    import java.io.InputStream;
    import java.io.OutputStream;
    import java.security.Key;
    import java.security.NoSuchAlgorithmException;
    import java.security.SecureRandom;
    import java.security.spec.AlgorithmParameterSpec;
    import javax.crypto.Cipher;
    import javax.crypto.CipherInputStream;
    import javax.crypto.CipherOutputStream;
    import javax.crypto.KeyGenerator;
    import javax.crypto.spec.IvParameterSpec;
    
    
    public class DESUtil {
    
        /**
         * CFB
         */
        public static final String CFB = "CFB";
    
        /**
         * OFB
         */
        public static final String OFB = "OFB";
    
        /**
         * CBC
         */
        public static final String CBC = "CBC";
    
        /**
         * iv向量
         */
        private static final byte[] DESIV = { (byte) 0xCE, (byte) 0x35, (byte) 0x5,
                (byte) 0xD, (byte) 0x98, (byte) 0x91, (byte) 0x8, (byte) 0xA };
    
        /**
         * AlgorithmParameterSpec
         */
        private static AlgorithmParameterSpec IV = null;
    
        /**
         * SHA1PRNG
         */
        private static final String SHA1PRNG = "SHA1PRNG";
    
        /**
         * DES默认模式
         */
        private static final String DES = "DES";
    
        /**
         * CBC加密模式
         */
        private static final String DES_CBC_PKCS5PADDING = "DES/CBC/PKCS5Padding";
    
        /**
         * OFB加密模式
         */
        private static final String DES_OFB_PKCS5PADDING = "DES/OFB/PKCS5Padding";
    
        /**
         * CFB加密模式
         */
        private static final String DES_CFB_PKCS5_PADDING = "DES/CFB/PKCS5Padding";
    
        /**
         * 加密模式
         */
        private static final int ENCRYPT_MODE = 1;
    
        /**
         * 解密模式
         */
        private static final int DECRYPT_MODE = 2;
    
        /**
         * 密钥
         */
        private Key key;
    
        public DESUtil(String str) {
            getKey(str);
        }
    
        public Key getKey() {
            return key;
        }
    
        public void setKey(Key key) {
            this.key = key;
        }
    
        /**
         * 通过密钥获得key
         * @param secretKey 密钥
         * @author sucb
         * @date 2017年2月28日下午1:17:58
         */
        public void getKey(String secretKey) {
            try {
                SecureRandom secureRandom = SecureRandom.getInstance(SHA1PRNG);
                secureRandom.setSeed(secretKey.getBytes());
                KeyGenerator generator = null;
                try {
                    generator = KeyGenerator.getInstance(DES);
                } catch (NoSuchAlgorithmException e) {
                }
                generator.init(secureRandom);
                IV = new IvParameterSpec(DESIV);
    
    
                this.key = generator.generateKey();
                generator = null;
    
            } catch (Exception e) {
                throw new RuntimeException("Error in getKey(String secretKey), Cause: " + e);
            }
        }
    
        /**
         * 字符串des加密
         * @param data 需要加密的字符串
         * @param encryptType 加密模式 (ECB/CBC/OFB/CFB)
         * @return 加密结果
         * @throws Exception 异常
         * @author sucb
         * @date 2017年3月2日下午7:47:37
         */
        public String encrypt(String data, String encryptType) throws Exception {
            Cipher cipher = getPattern(encryptType, ENCRYPT_MODE);
            byte[] pasByte = cipher.doFinal(data.getBytes("UTF-8"));
            return Base64.encodeBase64String(pasByte);
        }
    
        /**
         * 字符串des解密
         * @param data 需要解密的字符串
         * @param decryptType  解密模式 (ECB/CBC/OFB/CFB)
         * @return 解密结果
         * @throws Exception 异常
         * @author sucb
         * @date 2017年3月2日下午7:48:21
         */
        public String decrypt(String data, String decryptType) throws Exception {
            Cipher cipher = getPattern(decryptType, DECRYPT_MODE);
            byte[] pasByte = cipher.doFinal(Base64.decodeBase64(data));
            return new String(pasByte, "UTF-8");
        }
    
        /**
         * 初始化cipher
         * @param type  加密/解密模式 (ECB/CBC/OFB/CFB)
         * @param cipherMode cipher工作模式 1：加密； 2：解密
         * @return cipher
         * @throws Exception 异常
         * @author sucb
         * @date 2017年3月2日下午7:49:16
         */
        private Cipher getPattern(String type, int cipherMode) throws Exception {
            Cipher cipher;
            switch (type){
                case CBC :
                    cipher = Cipher.getInstance(DES_CBC_PKCS5PADDING);
                    cipher.init(cipherMode, key, IV);
                    break;
                case OFB :
                    cipher = Cipher.getInstance(DES_OFB_PKCS5PADDING);
                    cipher.init(cipherMode, key, IV);
                    break;
                case CFB :
                    cipher = Cipher.getInstance(DES_CFB_PKCS5_PADDING);
                    cipher.init(cipherMode, key, IV);
                    break;
                default :
                    cipher = Cipher.getInstance(DES);
                    cipher.init(cipherMode, key);
                    break;
            }
            return cipher;
        }
    
        /**
         * 文件 file 进行加密并保存目标文件 destFile 中
         * @param file 要加密的文件 如 c:/test/file.txt
         * @param destFile 加密后存放的文件名 如 c:/ 加密后文件 .txt
         * @param encryptType 加密模式 (ECB/CBC/OFB/CFB)
         * @return 加密结果   0：异常 1：加密成功； 5：未找到需要加密的文件
         * @author sucb
         * @date 2017年3月2日下午7:56:08
         */
        public int encryptFile(String file, String destFile, String encryptType) {
            int result = 0;
            try {
                Cipher cipher = getPattern(encryptType, ENCRYPT_MODE);
                InputStream is = new FileInputStream(file);
                OutputStream out = new FileOutputStream(destFile);
                CipherInputStream cis = new CipherInputStream(is, cipher);
                byte[] buffer = new byte[1024];
                int r;
                while ((r = cis.read(buffer)) > 0) {
                    out.write(buffer, 0, r);
                }
                cis.close();
                is.close();
                out.close();
                result = 1;
            } catch (FileNotFoundException e) {
                result = 5;
            } catch (Exception e) {
                e.printStackTrace();
            }
            return result;
        }
    
        /**
         * 文件 file 进行解密并保存目标文件 destFile 中
         * @param file 要解密的文件 如 c:/test/file.txt
         * @param destFile 解密后存放的文件名 如 c:/ 解密后文件 .txt
         * @param decryptType 解密模式 (ECB/CBC/OFB/CFB)
         * @return 解密结果 0：解密异常；1：解密正常；5：未找到需要解密的文件
         * @author sucb
         * @date 2017年3月2日下午7:58:56
         */
        public int decryptFile(String file, String destFile, String decryptType) {
            int result = 0;
            try {
                Cipher cipher = getPattern(decryptType, DECRYPT_MODE);
                InputStream is = new FileInputStream(file);
                OutputStream out = new FileOutputStream(destFile);
                CipherOutputStream cos = new CipherOutputStream(out, cipher);
                byte[] buffer = new byte[1024];
                int r;
                while ((r = is.read(buffer)) >= 0) {
                    cos.write(buffer, 0, r);
                }
                cos.close();
                out.close();
                is.close();
                result = 1;
            }catch (FileNotFoundException e) {
                result = 5;
            }  catch (Exception e) {
                e.printStackTrace();
            }
            return result;
        }
    
        public static void main(String[] args) throws Exception {
    
            String testString ="JCccc-你好，我/是/需/要/加*密*的*字*符*串.";
            System.out.println("加密前内容："+testString);
            String key="ABCDEFGHIJK";
            DESUtil desUtil = new DESUtil(key);
    
            String encryptStr = desUtil.encrypt(testString, "CBC");
            System.out.println("加密后：" + encryptStr);
            String decryptStr = desUtil.decrypt(encryptStr, "CBC");
            System.out.println("解密后：:" + decryptStr);
        }
    
    }

测试示例：

![20201117093552648.png][]

[20201117093552648.png]: /images/20221120/201eded4ee34478f9b75924ae8fafe4c.png