ASE加、解密

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.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

<script>
    function getAesString(data,key,iv){//加密

        var key  = CryptoJS.enc.Utf8.parse(key);
        //alert(key）;
        var iv   = CryptoJS.enc.Utf8.parse(iv);
        var encrypted =CryptoJS.AES.encrypt(data,key,
                {
                        iv:iv,
                mode:CryptoJS.mode.CBC,
                padding:CryptoJS.pad.Pkcs7
        });
        return encrypted.toString();    //返回的是base64格式的密文
    }
    function getDAesString(encrypted,key,iv){//解密
        var key  = CryptoJS.enc.Utf8.parse(key);
        var iv   = CryptoJS.enc.Utf8.parse(iv);
        var decrypted =CryptoJS.AES.decrypt(encrypted,key,
                {
                        iv:iv,
                mode:CryptoJS.mode.CBC,
                padding:CryptoJS.pad.Pkcs7
        });
        returndecrypted.toString(CryptoJS.enc.Utf8);      //
    }
    function getAES(){ //加密
        var data =document.getElementById("data-ipt").value;//明文
        var key  = 'abcdefgabcdefg12';  //密钥
        var iv   = 'abcdefgabcdefg12';
        var encrypted =getAesString(data,key,iv); //密文
        var encrypted1 =CryptoJS.enc.Utf8.parse(encrypted);
        document.getElementById("encrypted").innerHTML = encrypted;
    }

    function getDAes(){//解密
        var encrypted =document.getElementById("encrypted").innerHTML; //密文
        var key  = 'abcdefgabcdefg12';
        var iv   = 'abcdefgabcdefg12';
        var decryptedStr =getDAesString(encrypted,key,iv);
        alert(decryptedStr);
        document.getElementById("decrypted").innerHTML = decryptedStr;
    }
    </script>

　　

 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));  
    }