title: APDU for getting UID from MIFARE DESFire?
body: <p>I am new to APDUs. I read the datasheet for DESFire. According to it we have: </p>
  
  <pre><code>CLA  = 0x90     
  INS  = DESFire CMD Code                                            
  P1   = 0x00        
  P2   = 0x00
  LC   = Length of wrapped Data    
  data = DESFire command parameter(s) 
  LE   = 0x00
  </code></pre>
  
  <p>I want get the DESFire UID, but I can't create the command APDU for this. 
  Can anybody lead me into the right direction? I created this APDU but I am not sure if it's correct:</p>
  
  <pre><code>byte[8] cmd_apdu_getUID_part1= {0x90 , 0x93 , 0x20 , 0x00 , 0x00 , 0x00 , 0x00 , 0x00};
  </code></pre>
  
  <p>And I don't understand the concept of parameters like LC and I don't find INS for get UID. Is it <code>0x93 ox20</code> for part 1 of UID and <code>0x95 0x20</code> for part 2 of UID?</p>