Arduino uno RFID security system for PC / laptop

//=====================================Walid Mafuj===================================//
uint8_t buf[8] = { 0 };
#include <SPI.h>
#include <MFRC522.h> // RFID library
#define SS_PIN 10 //RX slave select
#define RST_PIN 9
int gled = 7; // optional
int rled = 4;// optional
MFRC522 mfrc522(SS_PIN, RST_PIN); // Create MFRC522 instance.
String card_ID=""; // 
String password="Password123" ; // Change It To Your Windows / fb / any Account's Password
String rfid="2222123818";// UID (unique Id Code Of Your Rfid Tag)
void setup() {
  Serial.begin(9600); // Initialize serial communications with the PC
  SPI.begin();  // Init SPI bus
  mfrc522.PCD_Init(); // Init MFRC522 card
  pinMode(gled,OUTPUT);
  pinMode(rled,OUTPUT);
}
void loop() {
  //look for new card
   if ( ! mfrc522.PICC_IsNewCardPresent()) {
  return;
 }
 if ( ! mfrc522.PICC_ReadCardSerial()) {
  return;//if read card serial(0) returns 1, the uid struct contians the ID of the read card.
 }
 for (byte i = 0; i < mfrc522.uid.size; i++) {
   card_ID += mfrc522.uid.uidByte[i];
 }
// Serial.println(card_ID);
       if(card_ID==rfid){digitalWrite(gled,HIGH);
      typeLiteralString(password);
      pressKey("enter"); releaseKey("enter");
     digitalWrite(gled,LOW); delay(200);digitalWrite(gled,HIGH); delay(200);digitalWrite(gled,LOW);
      }   
      if(card_ID!=password){
digitalWrite(rled,HIGH);    digitalWrite(rled,LOW); delay(200);digitalWrite(rled,HIGH); delay(200);digitalWrite(rled,LOW);  }      else{ goto cont;}   
delay(1000);
cont:
delay(1000);
card_ID="";
}
boolean isModifier(int keycode) {
    boolean result = false;
    if (keycode >= 224 && keycode <= 231) { // if the keycode is a modifier key
        result = true;
    }
    return result;
}

void pressModifier(String keyname) {
    pressModifier(getKeycode(keyname));
}
void pressModifier(int keycode) {
    int modifiermask = 0;
    if (isModifier(keycode)) { // if the keycode represents a modifier key
        modifiermask = getModifierMask(keycode);
        buf[0] = buf[0] | modifiermask;
        Serial.write(buf, 8); // Send key report
    }
}

void releaseModifier(String keyname) {
    releaseModifier(getKeycode(keyname));
}
void releaseModifier(int keycode) {
    int modifiermask = 0;
    if (isModifier(keycode)) { // if the keycode represents a modifier key
        modifiermask = getModifierMask(keycode);
        buf[0] = buf[0] & (~modifiermask);
        Serial.write(buf, 8); // Send key report
    }
}
void releaseAllModifiers() {
    buf[0] = B00000000;
    Serial.write(buf, 8); // Send key report
}

void pressKey(String keyname) {
    pressKey(getKeycode(keyname));
}
void pressKey(int keycode) { // TODO: cycle the 6 key spots in the report buffer instead of just using buf[2] each time.
    buf[2] = keycode;
    Serial.write(buf, 8); // Send key report
}

void releaseKey(String keyname) {
    releaseKey(getKeycode(keyname));
}
void releaseKey(int keycode) {
    // find the keycode in the report buffer, then set it to zero.
    int i=0;
    for (i=2; i<8; i++) {
        if (buf[i] == keycode) {
            buf[i] = 0;
        }
    }
    Serial.write(buf, 8); // Send key report
}
void releaseAllKeys() {
    int i=0;
    for (i=2; i<8; i++) {
        buf[i] = 0;
    }
    Serial.write(buf, 8); // Send key report
}

void pressSequenceOfKeys(const char * keySequence[], int numberOfKeys) {
    // This function can be good for pressing a few keys while holding a modifier down for example.

    int i = 0;
    for (i=0; i<numberOfKeys; i++) {
        pressKey(keySequence[i]);
        releaseKey(keySequence[i]);
    }
}

void typeLiteralString(String string) {
    char charArray[string.length()+1];
    string.toCharArray(charArray, string.length()+1);
    typeLiteralString(charArray, string.length());
}
void typeLiteralString(char string[], int stringLength) { // stringLength is the length of the printable string without considering the null byte.
    // This function will type the given string exactly as given, automatically pressing left_shift where necessary for capitals and symbols.

    // just in case:
    releaseAllKeys();
    releaseAllModifiers();

    boolean charNeedsShift = false;
    boolean shiftIsPressed = false;

    int i=0;
    for (i=0; i<stringLength; i++) {
        charNeedsShift = characterNeedsShift(string[i]);
        if (charNeedsShift && !shiftIsPressed) {
            pressModifier("left_shift");
            shiftIsPressed = true;
        }
        else if (!charNeedsShift && shiftIsPressed) {
            releaseModifier("left_shift");
            shiftIsPressed = false;
        }
        pressKey(String(string[i])); // without converting the char in string[i] to a String, arduino would prefer the pressKey(int) function instead of the pressKey(String) function, casting the char to a keycode (int) instead of a keyname (String).
        releaseKey(String(string[i])); // same as previous comment, but with releaseKey().
    }

    releaseAllModifiers();
}

boolean characterNeedsShift(char character) {
    int needsModifier = false;
    if ( // look up an ascii table and this will make sense.
        (character >= 33 && character <= 38)
        || (character >= 40 && character <= 43)
        || (character == 58)
        || (character == 60)
        || (character >= 62 && character <= 90)
        || (character >= 94 && character <= 95)
        || (character >= 123 && character <= 126)
    ) {
        needsModifier = true;
    }
    return needsModifier;
}

int getKeycode(String keyname) {
    String key = String(keyname); // Use a copy so that we don't mutate the user's String. Not sure if this is needed, but just in case. TODO: find out.
    key.toLowerCase();

    int keycode = 0; // keycode of zero means nothing pressed.

    // non-modifier keys
    if      (key == "a") { keycode =  4; }
    else if (key == "b") { keycode =  5; }
    else if (key == "c") { keycode =  6; }
    else if (key == "d") { keycode =  7; }
    else if (key == "e") { keycode =  8; }
    else if (key == "f") { keycode =  9; }
    else if (key == "g") { keycode = 10; }
    else if (key == "h") { keycode = 11; }
    else if (key == "i") { keycode = 12; }
    else if (key == "j") { keycode = 13; }
    else if (key == "k") { keycode = 14; }
    else if (key == "l") { keycode = 15; }
    else if (key == "m") { keycode = 16; }
    else if (key == "n") { keycode = 17; }
    else if (key == "o") { keycode = 18; }
    else if (key == "p") { keycode = 19; }
    else if (key == "q") { keycode = 20; }
    else if (key == "r") { keycode = 21; }
    else if (key == "s") { keycode = 22; }
    else if (key == "t") { keycode = 23; }
    else if (key == "u") { keycode = 24; }
    else if (key == "v") { keycode = 25; }
    else if (key == "w") { keycode = 26; }
    else if (key == "x") { keycode = 27; }
    else if (key == "y") { keycode = 28; }
    else if (key == "z") { keycode = 29; }

    else if (key == "1" || key == "!") { keycode = 30; }
    else if (key == "2" || key == "@") { keycode = 31; }
    else if (key == "3" || key == "#") { keycode = 32; }
    else if (key == "4" || key == "$") { keycode = 33; }
    else if (key == "5" || key == "%") { keycode = 34; }
    else if (key == "6" || key == "^") { keycode = 35; }
    else if (key == "7" || key == "&") { keycode = 36; }
    else if (key == "8" || key == "*") { keycode = 37; }
    else if (key == "9" || key == "(") { keycode = 38; }
    else if (key == "0" || key == ")") { keycode = 39; }

    else if (key == "enter" || key == "return")     { keycode = 40; }
    else if (key == "escape" || key == "")    { keycode = 41; }
    else if (key == "backspace" || key == "") { keycode = 42; }
    else if (key == "tab" || key == "  ")      { keycode = 43; }
    else if (key == "space" || key == " ")      { keycode = 44; }

    else if (key == "-" || key == "_")  { keycode = 45; }
    else if (key == "=" || key == "+")  { keycode = 46; }
    else if (key == "[" || key == "{")  { keycode = 47; }
    else if (key == "]" || key == "}")  { keycode = 48; }
    else if (key == "\\" || key == "|") { keycode = 49; }
    else if (key == ";" || key == ":")  { keycode = 51; }
    else if (key == "'" || key == "\"") { keycode = 52; }
    else if (key == "`" || key == "~")  { keycode = 53; }
    else if (key == "," || key == "<")  { keycode = 54; }
    else if (key == "." || key == ">")  { keycode = 55; }
    else if (key == "/" || key == "?")  { keycode = 56; }

    // TODO: Fix these keycodes. V
    else if (key == "capslock")         { keycode = 58; }

    else if (key == "f1")      { keycode = 59; }
    else if (key == "f2")      { keycode = 60; }
    else if (key == "f3")      { keycode = 61; }
    else if (key == "f4")      { keycode = 62; }
    else if (key == "f5")      { keycode = 63; }
    else if (key == "f6")      { keycode = 64; }
    else if (key == "f7")      { keycode = 65; }
    else if (key == "f8")      { keycode = 66; }
    else if (key == "f9")      { keycode = 67; }
    else if (key == "f10")     { keycode = 68; }
    else if (key == "f11")     { keycode = 69; }
    else if (key == "f12")     { keycode = 70; }

    else if (key == "print_screen")    { keycode = 70; }
    else if (key == "scroll_lock")     { keycode = 71; }
    else if (key == "pause")           { keycode = 72; }
    else if (key == "insert")          { keycode = 73; }
    else if (key == "home")            { keycode = 74; }
    else if (key == "page_up")         { keycode = 75; }
    else if (key == "delete")          { keycode = 76; }
    else if (key == "end")             { keycode = 77; }
    else if (key == "page_down")       { keycode = 78; }

    else if (key == "right_arrow")     { keycode = 79; }
    else if (key == "left_arrow")      { keycode = 80; }
    else if (key == "down_arrow")      { keycode = 81; }
    else if (key == "up_arrow")        { keycode = 82; }

    else if (key == "numlock" || key == "clear")   { keycode = 83; }

    //TODO: keypad and miscellaneous keys if you want them.

    // modifier keys.
    else if (key == "left_control")  { keycode = 224; }
    else if (key == "left_shift")    { keycode = 225; }
    else if (key == "left_alt")      { keycode = 226; }
    else if (key == "left_gui")      { keycode = 227; }

    else if (key == "right_control") { keycode = 228; }
    else if (key == "right_shift")   { keycode = 229; }
    else if (key == "right_alt")     { keycode = 230; }
    else if (key == "right_gui")     { keycode = 231; }

    return keycode;
}

int getModifierMask(String keyname) {
    return getModifierMask(getKeycode(keyname));
}
int getModifierMask(int keycode) { // return value of 0 means key is not a modifier.
    int modifiermask = 0;

    // NOTE: these are not the usage keycodes like for other keys, but rather the bit masks.
    if      (keycode == 224) { modifiermask = B00000001; } // left ctrl
    else if (keycode == 225) { modifiermask = B00000010; } // left shift
    else if (keycode == 226) { modifiermask = B00000100; } // left alt
    else if (keycode == 227) { modifiermask = B00001000; } // left gui
    else if (keycode == 228) { modifiermask = B00010000; } // right ctrl
    else if (keycode == 229) { modifiermask = B00100000; } // right shift
    else if (keycode == 230) { modifiermask = B01000000; } // right alt
    else if (keycode == 231) { modifiermask = B10000000; } // right gui

    return modifiermask;
}