Android 应用DES加密解密字符串

ゞ浴缸里的玫瑰 2022-06-17 08:06 195阅读 0赞

import java.security.InvalidKeyException;
    import java.security.NoSuchAlgorithmException;
    import java.security.spec.InvalidKeySpecException;
    
    import javax.crypto.BadPaddingException;
    import javax.crypto.Cipher;
    import javax.crypto.IllegalBlockSizeException;
    import javax.crypto.NoSuchPaddingException;
    import javax.crypto.SecretKey;
    import javax.crypto.SecretKeyFactory;
    import javax.crypto.spec.DESKeySpec;
    
    /***
     * @Description: des加密/解密类
     * @author zhouya
     * @version V1.0
     * 
     */
    public class Des {
    	/**
    	 * 加密（使用DES算法）
    	 * 
    	 * @param txt
    	 *            需要加密的文本
    	 * @param key
    	 *            密钥
    	 * @return 成功加密的文本
    	 * @throws InvalidKeySpecException
    	 * @throws InvalidKeyException
    	 * @throws NoSuchPaddingException
    	 * @throws IllegalBlockSizeException
    	 * @throws BadPaddingException
    	 */
    	public static String enCrypto(String txt, String key)
    			throws InvalidKeySpecException, InvalidKeyException,
    			NoSuchPaddingException, IllegalBlockSizeException,
    			BadPaddingException {
    		StringBuffer sb = new StringBuffer();
    		DESKeySpec desKeySpec = new DESKeySpec(key.getBytes());
    		SecretKeyFactory skeyFactory = null;
    		Cipher cipher = null;
    		try {
    			skeyFactory = SecretKeyFactory.getInstance("DES");
    			cipher = Cipher.getInstance("DES");
    		} catch (NoSuchAlgorithmException e) {
    			e.printStackTrace();
    		}
    		SecretKey deskey = skeyFactory.generateSecret(desKeySpec);
    		cipher.init(Cipher.ENCRYPT_MODE, deskey);
    		byte[] cipherText = cipher.doFinal(txt.getBytes());
    		for (int n = 0; n < cipherText.length; n++) {
    			String stmp = (java.lang.Integer.toHexString(cipherText[n] & 0XFF));
    
    			if (stmp.length() == 1) {
    				sb.append("0" + stmp);
    			} else {
    				sb.append(stmp);
    			}
    		}
    		return sb.toString().toUpperCase();
    	}
    
    	/**
    	 * 解密（使用DES算法）
    	 * 
    	 * @param txt
    	 *            需要解密的文本
    	 * @param key
    	 *            密钥
    	 * @return 成功解密的文本
    	 * @throws InvalidKeyException
    	 * @throws InvalidKeySpecException
    	 * @throws NoSuchPaddingException
    	 * @throws IllegalBlockSizeException
    	 * @throws BadPaddingException
    	 */
    	public static String deCrypto(String txt, String key)
    			throws InvalidKeyException, InvalidKeySpecException,
    			NoSuchPaddingException, IllegalBlockSizeException,
    			BadPaddingException {
    		DESKeySpec desKeySpec = new DESKeySpec(key.getBytes());
    		SecretKeyFactory skeyFactory = null;
    		Cipher cipher = null;
    		try {
    			skeyFactory = SecretKeyFactory.getInstance("DES");
    			cipher = Cipher.getInstance("DES");
    		} catch (NoSuchAlgorithmException e) {
    			e.printStackTrace();
    		}
    		SecretKey deskey = skeyFactory.generateSecret(desKeySpec);
    		cipher.init(Cipher.DECRYPT_MODE, deskey);
    		byte[] btxts = new byte[txt.length() / 2];
    		for (int i = 0, count = txt.length(); i < count; i += 2) {
    			btxts[i / 2] = (byte) Integer.parseInt(txt.substring(i, i + 2), 16);
    		}
    		return (new String(cipher.doFinal(btxts)));
    	}
    
    	public static void main(String[] args) throws InvalidKeyException,
    			NoSuchAlgorithmException, InvalidKeySpecException,
    			NoSuchPaddingException, IllegalBlockSizeException,
    			BadPaddingException {
    		String soureTxt = "这里是要加密的文本内容";
    		String key = "这里是自定义的密钥";
    		String str = null;
    		System.out.println("明文：" + soureTxt);
    		str = enCrypto(soureTxt, key);
    		System.out.println("加密：" + str);
    		System.out.println("解密：" + deCrypto(str, key));
    		System.out.println(str + "====" + key);
    
    	}
    }