JAVA实现AES 解密报错Input length must be multiple of 16 when decrypting with padded cipher

加密代码

　

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/**解密  * @param content  待解密内容  * @param password 解密密钥  * @return  */ public static byte[] decrypt(byte[] content, String password) {         try {                  KeyGenerator kgen = KeyGenerator.getInstance("AES");                  kgen.init(128, new SecureRandom(password.getBytes()));                  SecretKey secretKey = kgen.generateKey();                  byte[] enCodeFormat = secretKey.getEncoded();                  SecretKeySpec key = new SecretKeySpec(enCodeFormat, "AES");                             Cipher cipher = Cipher.getInstance("AES");// 创建密码器                 cipher.init(Cipher.DECRYPT_MODE, key);// 初始化                 byte[] result = cipher.doFinal(content);                 return result; // 加密         } catch (NoSuchAlgorithmException e) {                 e.printStackTrace();         } catch (NoSuchPaddingException e) {                 e.printStackTrace();         } catch (InvalidKeyException e) {                 e.printStackTrace();         } catch (IllegalBlockSizeException e) {                 e.printStackTrace();         } catch (BadPaddingException e) {                 e.printStackTrace();         }         return null; }

　　

　

解密代码

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/**解密  * @param content  待解密内容  * @param password 解密密钥  * @return  */ public static byte[] decrypt(byte[] content, String password) {         try {                  KeyGenerator kgen = KeyGenerator.getInstance("AES");                  kgen.init(128, new SecureRandom(password.getBytes()));                  SecretKey secretKey = kgen.generateKey();                  byte[] enCodeFormat = secretKey.getEncoded();                  SecretKeySpec key = new SecretKeySpec(enCodeFormat, "AES");                             Cipher cipher = Cipher.getInstance("AES");// 创建密码器                 cipher.init(Cipher.DECRYPT_MODE, key);// 初始化                 byte[] result = cipher.doFinal(content);                 return result; // 加密         } catch (NoSuchAlgorithmException e) {                 e.printStackTrace();         } catch (NoSuchPaddingException e) {                 e.printStackTrace();         } catch (InvalidKeyException e) {                 e.printStackTrace();         } catch (IllegalBlockSizeException e) {                 e.printStackTrace();         } catch (BadPaddingException e) {                 e.printStackTrace();         }         return null; }

　　

解密代码

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String content = "test"; String password = "12345678"; //加密 System.out.println("加密前：" + content); byte[] encryptResult = encrypt(content, password); try {         String encryptResultStr = new String(encryptResult,"utf-8");         //解密         byte[] decryptResult = decrypt(encryptResultStr.getBytes("utf-8"),password);         System.out.println("解密后：" + new String(decryptResult)); } catch (UnsupportedEncodingException e) {         e.printStackTrace(); }

　　

偶尔会报错 抛出异常，

javax.crypto.IllegalBlockSizeException: Input length must be multiple of 16 when decrypting with padded cipher

 

原因  加密后的byte数组是不能强制转换成字符串的，换言之：字符串和byte数组在这种情况下不是互逆的；要避免这种情况，我们需要做一些修订，可以考虑将二进制数据转换成十六进制表示

解决方案 

 

二进制转换成16进制

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/**将16进制转换为二进制  * @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; }

　　

16进制转换为二进制

 

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/**将16进制转换为二进制  * @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; }

　　

 测试结果，问题解决

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String content = "test"; String password = "12345678"; //加密 System.out.println("加密前：" + content); byte[] encryptResult = encrypt(content, password); String encryptResultStr = parseByte2HexStr(encryptResult); System.out.println("加密后：" + encryptResultStr); //解密 byte[] decryptFrom = parseHexStr2Byte(encryptResultStr); byte[] decryptResult = decrypt(decryptFrom,password); System.out.println("解密后：" + new String(decryptResult));

　　

测试结果如下：

加密前：test
加密后：73C58BAFE578C59366D8C995CD0B9D6D
解密后：test

 

 

 

文档参考 http://blog.csdn.net/hbcui1984/article/details/5201247