微信小程序读取NFC-MifareClassic1K卡-M1卡详解_微信小程序支持的nfc卡片有哪些

最近好多朋友私信我想问小程序M1卡的读写问题，现在我给大家伙详细的剖析一下流程。

首先了解一下M1卡的基础知识

M1卡的内存图谱

我们把M1的内存区比作一个硬盘，它的16个扇区就相当于把硬盘分区分了A、B、C...等16个磁盘，每个磁盘上又创了四个文件（块0，块1，块2，块3），每个块都是用16个字节的16进制存放数据

块3：存放了当前扇区的密钥A（占用0-5字节）、密钥B（占用10-15字节）、和各个块的访问控制权限（占用6-9字节）

块0~块2：存放用户自定义的数据

认证：

认证是M1进行读取和写入之前必须处理的操作，如果你要操作的块读写只需要密钥A的认证，那就只要做一次密钥A的认证就可以进行读写了，这完全取决于上面说的访问控制权限,关于访问控制本文就不细讲了，想了解的可以去百度学习一下。

指令：

小程序实现M1的认证读取：

//请阅读如下代码注释

 
let adapter;//定义一个NFC适配器
let mifare;
 
adapter = wx.getNFCAdapter();
    adapter.startDiscovery({
      success:function(){
        console.log('开启NFC适配器成功。');  
      },
      fail:function(res){
        console.log('开启NFC适配器失败！');
        
        if(res.errCode==13000){
          //当前设备不支持NFC
        }else if(res.errCode==13001){
          //系统NFC开关未打开
        }else{
          //未知错误
        }
      }
    });
 
    //注册发现芯片后处理事件
    adapter.onDiscovered(discoverHandlerAuthAndReadM1);
 
    
//认证并读取M1卡指定分区处理事件
var discoverHandlerAuthAndReadM1=function(res){
  if(res.techs.indexOf('MIFARE Classic') != -1){
    GetTagMemery_14443A_MifareClassic(M1Pwd1,M1Pwd2,M1ReadNum);
  }else{
    //芯片协议不匹配
  }
}
 
//读取14443A MifareClassic内存数据
function GetTagMemery_14443A_MifareClassic(pwd1,pwd2,index){
    //读取扇区...
    mifare = adapter.getMifareClassic();
    mifare.connect({
      success: function (ress) {
        console.log('MifareClassic已连接',ress);
        //认证
        var cmd = new Int8Array(12);
        //认证指令: 60（KEYA） + 扇区编号 + UID + 12位HEX密钥
        if(pwd1!=""){
          cmd[0] = parseInt("0x60");
        }else{
          cmd[0] = parseInt("0x61");
        }
        
        cmd[1] = parseInt(parseInt(index)*4, 10);
        for (var j = 0; j < uid_arr.length; j++) {
          cmd[j + 2] = uid_arr[j];
        }
  
         if(pwd1!=""){
          cmd[6] = chipTool.hex2int(pwd1.substring(0, 2));
          cmd[7] = chipTool.hex2int(pwd1.substring(2, 4));
          cmd[8] = chipTool.hex2int(pwd1.substring(4, 6));
          cmd[9] = chipTool.hex2int(pwd1.substring(6, 8));
          cmd[10] = chipTool.hex2int(pwd1.substring(8, 10));
          cmd[11] = chipTool.hex2int(pwd1.substring(10, 12));
        }else{
          cmd[6] = chipTool.hex2int(pwd2.substring(0, 2));
          cmd[7] = chipTool.hex2int(pwd2.substring(2, 4));
          cmd[8] = chipTool.hex2int(pwd2.substring(4, 6));
          cmd[9] = chipTool.hex2int(pwd2.substring(6, 8));
          cmd[10] = chipTool.hex2int(pwd2.substring(8, 10));
          cmd[11] = chipTool.hex2int(pwd2.substring(10, 12));
        }
        var cmdBuffer = cmd.buffer;
        //console.log("认证指令为：", cmdBuffer);
        //console.log('使用密钥:'+pwd);
        mifare.transceive({//发送密钥
          data: cmdBuffer,
          success: function (res) {
            console.log('认证成功, 接收数据如下:', res);
            
          },
          fail: function (err) {
            //密钥认证失败
            mifare.close();
            adapter.offDiscovered(discoverHandlerAuthAndReadM1);
            adapter.stopDiscovery();
            console.log('认证失败', err);
          }
        });
        
      },
      fail: function (err) {
        //mifare连接失败
        mifare.close();
        adapter.offDiscovered(discoverHandlerAuthAndReadM1);
        adapter.stopDiscovery();
        //console.log('mifare连接失败');
      },
      complate: function (cp) {
       
      }
    })
    
    mifare.isConnected({
      success: function (isConnected) {//连接成功
        //读取该分区数据
        var areaNum=index;
        var max=parseInt(areaNum)*4+3;
        for (let i = 0; i < 4; i++) {
          if(pwd1!=""){
            getMifareClassicBlockData(parseInt(areaNum)*4+i,max,pwd1);
          }else{
            getMifareClassicBlockData(parseInt(areaNum)*4+i,max,pwd2);
          }
        }
      }
    });
  }
 
//获取MifareClassic指定区块
function getMifareClassicBlockData(blockNum,maxBlock,pwd){
    var cmd = new Int8Array(2);
    cmd[0] = parseInt("0x30");
    cmd[1] = parseInt(blockNum, 10);
    var cmdBuffer = cmd.buffer;
    let block_info_tmp = '';
    //console.log("读取指令为：", cmdBuffer);
    mifare.transceive({
      data: cmdBuffer,
      success: function (res) {
        //console.log('读取数据:', res);
        var block_tmp = new Uint8Array(res.data);
        for (var j = 0; j < block_tmp.length; j++) {
          var tmp = block_tmp[j].toString(16);
          if (tmp.length < 2) {
            tmp = '0' + tmp;
          }
          if(j==block_tmp.length-1){
            block_info_tmp += tmp;
          }else{
            block_info_tmp += tmp + ":";
          }
        }
        console.log('第'+blockNum+'块读取数据返回HEX',block_info_tmp);
      },
      fail: function (err) {
        console.log('读取区块'+blockNum+'失败', err);
      },
      complete:function(){
        if(blockNum==maxBlock){
          //console.log('M1分区读取结果:',blockInfosM1);
          mifare.close();
          adapter.offDiscovered(discoverHandlerAuthAndReadM1);
          adapter.stopDiscovery();
          console.log('关闭mifare连接');
        }
      }
    })
  }