ASE加、解密-白红宇

ASE加、解密

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发布时间：2019-06-29

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AES已经变成目前对称加密中最流行算法之一；AES可以使用128、192、和256位密钥，并且用128位分组加密和解密数据。

/**     * 加密     *     * @param content 需要加密的内容     * @param password  加密密码     * @return     */    public static byte[] encrypt(String content, String password) {        try {            KeyGenerator kgen = KeyGenerator.getInstance("AES");　　　　//创建AES的key生产者            kgen.init(128, new SecureRandom(password.getBytes()));　　//利用用户密码作为随机码初始化　　　　　　　　　//使其具有确定的128个字节的密钥大小，SecureRandom是生成安全随机数序列，　　　　　　　　//password.getBytes()是种子，只要种子相同，序列就一样，所以解密只要有password就行            SecretKey secretKey = kgen.generateKey();　　　　//根据用户密码生成密钥            byte[] enCodeFormat = secretKey.getEncoded();　　//返回基本编码格式的密钥，如果此密钥不支持编码，返回null            SecretKeySpec key = new SecretKeySpec(enCodeFormat, "AES");　　//根据给定的字节数组构造一个为AES专用密钥            Cipher cipher = Cipher.getInstance("AES");　　　　// 创建密码器            byte[] byteContent = content.getBytes("utf-8");            cipher.init(Cipher.ENCRYPT_MODE, key);　　　　　　// 初始化为加密模式            byte[] result = cipher.doFinal(byteContent);            return result; // 加密        } catch (NoSuchAlgorithmException e) {            e.printStackTrace();        } catch (NoSuchPaddingException e) {            e.printStackTrace();        } catch (InvalidKeyException e) {            e.printStackTrace();        } catch (UnsupportedEncodingException e) {            e.printStackTrace();        } catch (IllegalBlockSizeException e) {            e.printStackTrace();        } catch (BadPaddingException e) {            e.printStackTrace();        }        return null;    }

注意：解密的时候要传入byte数组

/**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;         } 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;    }

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

输出结果如下：

加密前：test

解密后：test

容易出错的地方

但是如果我们将测试代码修改一下，如下：

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();}

则，系统会报出如下异常：

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

at com.sun.crypto.provider.SunJCE_f.b(DashoA13*..)

at com.sun.crypto.provider.AESCipher.engineDoFinal(DashoA13*..)

at javax.crypto.Cipher.doFinal(DashoA13*..)

这主要是因为加密后的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，主要有如下两个方

将二进制转换成16进制

**将二进制转换成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进制转换为二进制

/**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;  }

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

也可以使用BASE64进行包装处理。

加密bytes[] ----> passwordStr: new String(new BASE64Encoder().encode(doFinal))

解密String --->  new BASE64Decoder().decodeBuffer(passwordStr)

public static String generatePasswordAES2(String password, String passwordKey) {        try {            KeyGenerator keyGenerator = KeyGenerator.getInstance("AES");            keyGenerator.init(128, new SecureRandom(passwordKey.getBytes("UTF-8")));            SecretKey secretKey = keyGenerator.generateKey();            byte[] encoded = secretKey.getEncoded();            SecretKey key = new SecretKeySpec(encoded, "AES");            Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5Padding");            System.out.println("密钥的长度为：" + key.getEncoded().length);            cipher.init(Cipher.ENCRYPT_MODE, key);            byte[] userPasswordBytes = password.getBytes("UTF-8");            byte[] doFinal = cipher.doFinal(userPasswordBytes);            String passwordBase64 = new String(new BASE64Encoder().encode(doFinal));            return passwordBase64;        } catch (Exception e) {            throw new BadRequestException("密码加密错误。");        }    }

public static String decryptPassword(String password, String token) {        try {            KeyGenerator keyGenerator = KeyGenerator.getInstance("AES");            keyGenerator.init(128, new SecureRandom(token.getBytes("UTF-8")));            SecretKey secretKey = keyGenerator.generateKey();            byte[] encoded = secretKey.getEncoded();            SecretKey key = new SecretKeySpec(encoded, "AES");            Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5Padding");            cipher.init(Cipher.DECRYPT_MODE, key);            byte[] passwordBytes = new BASE64Decoder().decodeBuffer(password);            //解密            byte[] passwordDoFinal = cipher.doFinal(passwordBytes);            String decrypt = new String(passwordDoFinal, "UTF-8");            return decrypt;        } catch (Exception e) {            throw new BadRequestException("密码解密错误:" + e.getMessage());        }    }

AES-CBC-PKCS5

public static void main(String[] args)throws UnsupportedEncodingException {           Stringcontent="12345678";           Stringkey="abcdefgabcdefg12";           Stringiv="abcdefgabcdefg12";           //加密          byte[ ]encrypted=AES_CBC_Encrypt(content.getBytes(), key.getBytes(), iv.getBytes());          //解密          byte[ ]decrypted=AES_CBC_Decrypt(encrypted, key.getBytes(), iv.getBytes());                    System.out.println("解密后："+byteToHexString(decrypted));         System.out.println(byteToString(decrypted));      }       public static String byteToString(byte[ ]byte1){           returnnew String(byte1);      }      public static byte[] AES_CBC_Encrypt(byte[]content, byte[] keyBytes, byte[] iv){                      try{               SecretKeySpec key = newSecretKeySpec(keyBytes, "AES");              Ciphercipher=Cipher.getInstance("AES/CBC/PKCS5Padding");               cipher.init(Cipher.ENCRYPT_MODE,key, new IvParameterSpec(iv));               byte[]result=cipher.doFinal(content);              return result;          }catch (Exception e) {              System.out.println("exception:"+e.toString());           }            return null;       }              public static byte[] AES_CBC_Decrypt(byte[]content, byte[] keyBytes, byte[] iv){                      try{                    SecretKeySpec key = newSecretKeySpec(keyBytes, "AES");              Ciphercipher=Cipher.getInstance("AES/CBC/PKCS5Padding");               cipher.init(Cipher.DECRYPT_MODE,key, new IvParameterSpec(iv));               byte[]result=cipher.doFinal(content);               return result;           }catch (Exception e) {               // TODO Auto-generated catchblock               System.out.println("exception:"+e.toString());           }            return null;       }   /**      * 字符串装换成base64      *       * @param key      * @return      * @throws Exception      */       public static byte[] decryptBASE64(Stringkey) throws Exception {            returnBase64.decodeBase64(key.getBytes());      }              /**      *二进制装换成base64      *       * @param key      * @return      * @throws Exception      */       public static String encryptBASE64(byte[]key) throws Exception {            returnnew String(Base64.encodeBase64(key));      }

转载于:https://www.cnblogs.com/skyLogin/p/6767640.html

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