package com.zgrb.utils;

import java.security.Security;

import org.apache.commons.codec.binary.Base64;
import org.bouncycastle.jce.provider.BouncyCastleProvider;
import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
import java.io.UnsupportedEncodingException;
import java.security.*;
import java.security.spec.InvalidParameterSpecException;

public class AesCbcUtil {    
 static {        
  //BouncyCastle是一个开源的加解密解决方案，主页在http://www.bouncycastle.org/        
  Security.addProvider(new BouncyCastleProvider());    
 }        
 public static String decrypt(String data, String key, String iv) throws Exception {
  //        initialize();         //被加密的数据        
  byte[] dataByte = Base64.decodeBase64(data);        
  //加密秘钥        
  byte[] keyByte = Base64.decodeBase64(key);        
  //偏移量        
  byte[] ivByte = Base64.decodeBase64(iv);        
  try {            
   Cipher cipher = Cipher.getInstance("AES/CBC/PKCS7Padding");            
   SecretKeySpec spec = new SecretKeySpec(keyByte, "AES");            
   AlgorithmParameters parameters = AlgorithmParameters.getInstance("AES");            
   parameters.init(new IvParameterSpec(ivByte));            
   cipher.init(Cipher.DECRYPT_MODE, spec, parameters);
   // 初始化            
   byte[] resultByte = cipher.doFinal(dataByte);            
   if (null != resultByte && resultByte.length > 0) {                
    String result = new String(resultByte, "UTF-8");                
    return result;           
   }           
   return null;        
  } catch (NoSuchAlgorithmException e) {            
   e.printStackTrace();        
  } catch (NoSuchPaddingException e) {            
   e.printStackTrace();        
  } catch (InvalidParameterSpecException e) {            
   e.printStackTrace();        
  } catch (InvalidKeyException e) {            
   e.printStackTrace();        
  } catch (InvalidAlgorithmParameterException e) {            
   e.printStackTrace();        
  } catch (IllegalBlockSizeException e) {            
   e.printStackTrace();        
  } catch (BadPaddingException e) {            
   e.printStackTrace();        
  } catch (UnsupportedEncodingException e) {            
   e.printStackTrace();        
  }        
  return null;
 }
}