智能音箱是目前热火的智能产品,有很多家企业推出自己的智能音箱,并且进行了开放平台,允许第三方开发者,基于开放平台进行应用开发,丰富自己产品功能。
本人则购买一台 京东与讯飞合作的产品,叮咚智能音箱。并且在里面开发一个小应用“小军找手机”,
但在开发过程中遇到一个坑,利用C#开发语言,实现叮咚开放平台 的加解密。因为叮咚平台是用JAVA加密,我主用C#语言。
平台在第三方应用中需要进行参数设置,见下图,要求设置密钥,即128个字符的字符串。因官方采用JAVA语言开发,如果第三方应用采用.NET 开发,则按页面中的JAVA的方式无法正确解密回明文的state ,即json:{"userid":"用户标识","operation":"oauth","timestamp":"时间戳,毫秒","appid":"应用的APPID"} 。这段字符串的反解。
官方应用对state参数的解密过程
1.应用将接收到的数据进行Url解码,state_base64 = UrlDecoder.decode(state,"UTF-8")
2.应用将解码后到的数据进行Base64解码 state_mi = Base64.decode(state_base64)
3.应用使用应用配置的AesKey秘钥进行数据的解密 state = AES.decrypt(state_mi,AesKey)
应用.NET进行参数解密的过程
1.用附的JAVA代码 见下,将代码中key='12345578 中的变量key ,替换成你自己所用的回调地址参数秘钥,即参数配置中的秘钥。
2.在DOS环境,运行javac TestGenAESByteKey和java TestGenAESByteKey 然后得到类似这种的字符串 a0UcXq pLnhoWpzpHYcl1+A==
以上两步,在第三方应用的代码方法之外使用,因为一些底层加密的原因,具体的不作讨论。
3.下面 C# 代码 Decrypt方法 反解出 state。这部分在第三方应用中
附JAVA代码:
import java.io.UnsupportedEncodingException;
import java.security.NoSuchAlgorithmException;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import sun.misc.BASE64Encoder;
public class TestGenAESByteKey{
/**
* @param args
* @throws UnsupportedEncodingException
* @throws NoSuchAlgorithmException
*/
public static void main(String[] args) throws UnsupportedEncodingException, NoSuchAlgorithmException {
String key="12345678123456768123456781234567681234567812345676812345678123456768123456781234567681234567812345676812345678123456768123456781";
KeyGenerator kgen = KeyGenerator.getInstance("AES");
java.security.SecureRandom random = java.security.SecureRandom.getInstance("SHA1PRNG");
random.setSeed(key.getBytes());
kgen.init(128, random);
SecretKey secretKey = kgen.generateKey();
byte[] enCodeFormat = secretKey.getEncoded();
BASE64Encoder coder = new BASE64Encoder();
System.out.println(coder.encode(enCodeFormat));
}
}
附C#代码
/// <summary>
/// 服务开启关闭回调
/// </summary>
/// <param name="state"></param>
/// <returns></returns>
public ContentResult OpenService(string state)
{
string state_base64 = HttpUtility.UrlDecode(state,Encoding.UTF8);
String decrypt_state = Decrypt(state_base64);
///下面为具体的业务逻辑
}
private static string Decrypt(string toDecrypt)
{
byte[] keyArray = Convert.FromBase64String(@"a0UcbepLnhoWpzpHYcl1+A==");
byte[] inputBuffer = Convert.FromBase64String(toDecrypt);
RijndaelManaged rDel = new RijndaelManaged();
rDel.Key = keyArray;
rDel.Mode = CipherMode.ECB;
rDel.Padding = PaddingMode.PKCS7;
ICryptoTransform cTransform = rDel.CreateDecryptor();
byte[] resultArray = cTransform.TransformFinalBlock(inputBuffer, 0, inputBuffer.Length);
return Encoding.UTF8.GetString(resultArray);
}
/* structure that hold data*/
typedef struct{
int sender;
int counter;
}Data;
/* this variable hold queue handle */
xQueueHandle xQueue;
void setup() {
Serial.begin(112500);
/* create the queue which size can contains 5 elements of Data */
xQueue = xQueueCreate(5, sizeof(Data));
xTaskCreate(
sendTask1, /* Task function. */
"sendTask1", /* name of task. */
10000, /* Stack size of task */
NULL, /* parameter of the task */
2, /* priority of the task */
NULL); /* Task handle to keep track of created task */
xTaskCreate(
sendTask2, /* Task function. */
"sendTask2", /* name of task. */
10000, /* Stack size of task */
NULL, /* parameter of the task */
2, /* priority of the task */
NULL); /* Task handle to keep track of created task */
xTaskCreate(
receiveTask, /* Task function. */
"receiveTask", /* name of task. */
10000, /* Stack size of task */
NULL, /* parameter of the task */
1, /* priority of the task */
NULL); /* Task handle to keep track of created task */
}
void loop() {
}
void sendTask1( void * parameter )
{
/* keep the status of sending data */
BaseType_t xStatus;
/* time to block the task until the queue has free space */
const TickType_t xTicksToWait = pdMS_TO_TICKS(100);
/* create data to send */
Data data;
/* sender 1 has id is 1 */
data.sender = 1;
data.counter = 1;
for(;;){
Serial.println("sendTask1 is sending data");
/* send data to front of the queue */
xStatus = xQueueSendToFront( xQueue, &data, xTicksToWait );
/* check whether sending is ok or not */
if( xStatus == pdPASS ) {
/* increase counter of sender 1 */
data.counter = data.counter + 1;
}
/* we delay here so that receiveTask has chance to receive data */
delay(1000);
}
vTaskDelete( NULL );
}
/* this task is similar to sendTask1 */
void sendTask2( void * parameter )
{
BaseType_t xStatus;
const TickType_t xTicksToWait = pdMS_TO_TICKS(100);
Data data;
data.sender = 2;
data.counter = 1;
for(;;){
Serial.println("sendTask2 is sending data");
xStatus = xQueueSendToFront( xQueue, &data, xTicksToWait );
if( xStatus == pdPASS ) {
data.counter = data.counter + 1;
}
delay(1000);
}
vTaskDelete( NULL );
}
void receiveTask( void * parameter )
{
/* keep the status of receiving data */
BaseType_t xStatus;
/* time to block the task until data is available */
const TickType_t xTicksToWait = pdMS_TO_TICKS(100);
Data data;
for(;;){
/* receive data from the queue */
xStatus = xQueueReceive( xQueue, &data, xTicksToWait );
/* check whether receiving is ok or not */
if(xStatus == pdPASS){
/* print the data to terminal */
Serial.print("receiveTask got data: ");
Serial.print("sender = ");
Serial.print(data.sender);
Serial.print(" counter = ");
Serial.println(data.counter);
}
}
vTaskDelete( NULL );
}