解决AES解密出现数据被截断的问题

AES/CBC/NoPadding加密后数据使用PKCS7Padding补码方式解密后出现数据被截断的问题

• java不支持 PKCS7Padding补码方式
   

  public static String encrypt(String Data, String password){
      try {
              byte[] iv = DEFAULT_IV.getBytes(DEFAULT_CHARSET);
              Cipher cipher = Cipher.getInstance("AES/CBC/PKCS7Padding");
              int blockSize = cipher.getBlockSize();
              byte[] dataBytes = Data.getBytes(DEFAULT_CHARSET);
              int plaintextLength = dataBytes.length;
              if (plaintextLength % blockSize != 0) {
                  plaintextLength = plaintextLength + (blockSize - (plaintextLength % blockSize));
              }
              byte[] plaintext = new byte[plaintextLength];
              System.arraycopy(dataBytes, 0, plaintext, 0, dataBytes.length);
              IvParameterSpec ivspec = new IvParameterSpec(iv);
              cipher.init(Cipher.ENCRYPT_MODE, getSecretKey(password), ivspec);
              byte[] encrypted = cipher.doFinal(plaintext);
              return Base64Utils.encodeToString(encrypted);//将cipher加密后的byte数组用base64编码生成字符串
          } catch (Exception e) {
          	logger.warn("【加密失败】明文:("+Data+") 密钥:"+password);
              e.printStackTrace();
              return null;
          }
  }
  //======================================================================
  public static void main(String[] args) throws Exception {
          String data = "abc";
          String passwordEnc = AESUtil.encrypt(data, "123456");//进行java的AES/CBC/NoPadding加密
          System.out.println(passwordEnc.length());
  }
  //======================================================================
  java.security.NoSuchAlgorithmException: Cannot find any provider supporting AES/CBC/PKCS7Padding
  	at javax.crypto.Cipher.getInstance(Cipher.java:535)

   

• 不使用第三方库实现PKCS7Padding补码方式
   

      //此函数是pkcs7padding填充函数
      public static String pkcs7padding(String data) {
          int bs = 16;
          int padding = bs - (data.length() % bs);
          String padding_text = "";
          for (int i = 0; i < padding; i++) {
              padding_text += (char)padding;
          }
          return data+padding_text;
      }
  //======================================================================
  public static void main(String[] args) throws Exception {
          String data = "abc";
          data = AESUtil.pkcs7padding(data);
          String passwordEnc = AESUtil.encrypt(data, "123456");//进行java的AES/CBC/NoPadding加密
          System.out.println(passwordEnc.length());
  }
  //======================================================================
  加密之后的字符串:Gc9AmBtRpk7Z7Lv9C7JomA==