package videoalliance;

import java.io.UnsupportedEncodingException;

import javax.crypto.Cipher;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;

import org.apache.commons.lang.StringUtils;

import com.chinacreator.common.exception.BusinessException;

/**
 * AES加密工具类
 */
public class AESUtil {

	private static final byte[] IV = new byte[16];  
	
	/**
	 * 二进制转变为16进制
	 * 
	 * @param buf
	 * @return
	 */
	public static String parseByte2HexStr(byte[] buf) {
		StringBuffer sb = new StringBuffer();
		for (int i = 0; i < buf.length; i++) {
			String hex = Integer.toHexString(buf[i] & 0xFF);
			if (hex.length() == 1) {
				hex = '0' + hex;
			}
			sb.append(hex.toUpperCase());
		}
		return sb.toString();
	}

	/**
	 * 将16进制转变为二进制
	 * 
	 * @param hexStr
	 * @return
	 */
	public static byte[] parseHexStr2Byte(String hexStr) {
		if (hexStr.length() < 1) {
			return null;
		}
		byte[] result = new byte[hexStr.length() / 2];
		for (int i = 0; i < hexStr.length() / 2; i++) {
			int high = Integer.parseInt(hexStr.substring(i * 2, i * 2 + 1), 16);
			int low = Integer.parseInt(hexStr.substring(i * 2 + 1, i * 2 + 2), 16);
			result[i] = (byte) (high * 16 + low);
		}
		return result;
	}

	/**
	 * AES解密
	 * 
	 * @param content
	 *            密文
	 * @param keyWord
	 *            密钥
	 * @return
	 * @throws BusinessException 
	 * @throws Exception
	 */
	public static byte[] decrypt(byte[] content, String keyWord) throws BusinessException {
		if(StringUtils.isEmpty(keyWord)) {
			return null;
		}
		try {
			SecretKeySpec key = new SecretKeySpec(keyWord.getBytes(), "AES");
			Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
			cipher.init(Cipher.DECRYPT_MODE, key, new IvParameterSpec(IV));
			byte[] result = cipher.doFinal(content);
			return result;
		} catch (Exception e) {
			throw new BusinessException("9010", "解密失败");
		}
	}

	/**
	 * AES 解密
	 * 
	 * @param content
	 *            密文
	 * @param keyWord
	 *            密钥
	 * @return
	 * @throws UnsupportedEncodingException 
	 * @throws BusinessException 
	 */
	public static String decrypt(String content, String keyWord) throws UnsupportedEncodingException, BusinessException {
		if(StringUtils.isEmpty(content)) {
			return null;
		}
		byte[] contentBytes = parseHexStr2Byte(content);
		byte[] result = decrypt(contentBytes, keyWord);
		return new String(result, "UTF-8");
	}

	/**
	 * AES 加密
	 * 
	 * @param content
	 *            内容
	 * @param keyWord
	 *            密钥
	 * @return
	 * @throws BusinessException 
	 */
	public static byte[] encrypt(byte[] content, String keyWord) throws BusinessException {
		if(StringUtils.isEmpty(keyWord)) {
			return null;
		}
	    try {
			SecretKeySpec key = new SecretKeySpec(keyWord.getBytes(), "AES"); 
			Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");  
			cipher.init(Cipher.ENCRYPT_MODE, key, new IvParameterSpec(IV));  
			byte[] encryptedData = cipher.doFinal(content); 
			return encryptedData;
		} catch (Exception e) {
			throw new BusinessException("9010", "加密失败");
		}
	}

	/**
	 * AES 加密
	 * 
	 * @param content
	 *            内容
	 * @param keyWord
	 *            密钥
	 * @return
	 * @throws UnsupportedEncodingException 
	 * @throws BusinessException 
	 */
	public static String encrypt(String content, String keyWord) throws UnsupportedEncodingException, BusinessException {
		if(StringUtils.isEmpty(content)) {
			return null;
		}
		byte[] result = encrypt(content.getBytes("UTF-8"), keyWord);
		return parseByte2HexStr(result);
	}
	
	public static void main(String[] args) throws UnsupportedEncodingException, BusinessException {
		System.out.println(decrypt("7EED1F816FEFB5EABEA99967BBCC2274".toLowerCase(), "1234567812345678"));
	}
}