Author: adnanafzal565

<?php

$conn = new PDO("mysql:host=localhost;dbname=end_to_end_encryption", "root", "");

<?php

require_once "db.php";

$sql = "CREATE TABLE IF NOT EXISTS users(
  id INTEGER NOT NULL AUTO_INCREMENT PRIMARY KEY,
  email VARCHAR(255) NOT NULL,
  privateKey TEXT DEFAULT NULL,
  publicKey TEXT DEFAULT NULL
)";
$conn->prepare($sql)->execute();

$sql = "CREATE TABLE IF NOT EXISTS messages(
  id INTEGER NOT NULL AUTO_INCREMENT PRIMARY KEY,
  sender VARCHAR(255) NOT NULL,
  receiver VARCHAR(255) NOT NULL,
  message TEXT NOT NULL,
  iv TEXT NOT NULL
)";
$conn->prepare($sql)->execute();

?>

http://localhost/end-to-end-encryption-js-php-mysql/index.php

<form onsubmit="doLogin(this)">
  <input type="email" name="email" id="email" placeholder="Enter email" />
  <input type="submit" value="Login" />
</form>

<script>
  function doLogin() {
    event.preventDefault()
    
    const form = event.target
    const formData = new FormData(form)
    
    const ajax = new XMLHttpRequest()
    ajax.open("POST", "login.php", true)
    ajax.onreadystatechange = function () {
      if (this.readyState == 4 && this.status == 200) {
        if (!this.responseText) {
          updateKeys()
        }
      }
    }

    ajax.send(formData)
  }
</script>

<?php

require_once "db.php";
$email = $_POST["email"];

$sql = "SELECT publicKey FROM users WHERE email = ?";
$result = $conn->prepare($sql);
$result->execute([
  $email
]);
$user = $result->fetchObject();

echo ($user && $user->publicKey != null);
exit();

async function updateKeys() {
      const keyPair = await window.crypto.subtle.generateKey(
          {
              name: "ECDH",
              namedCurve: "P-256",
          },
          true,
          ["deriveKey", "deriveBits"]
      )

      const publicKeyJwk = await window.crypto.subtle.exportKey(
          "jwk",
          keyPair.publicKey
      )

      const privateKeyJwk = await window.crypto.subtle.exportKey(
          "jwk",
          keyPair.privateKey
      )

      const formData = new FormData()
      formData.append("email", document.getElementById("email").value)
      formData.append("publicKey", JSON.stringify(publicKeyJwk))
      formData.append("privateKey", JSON.stringify(privateKeyJwk))

      const ajax = new XMLHttpRequest()
      ajax.open("POST", "update-keys.php", true)
      ajax.onreadystatechange = function () {
        if (this.readyState == 4 && this.status == 200) {
          console.log(this.responseText)
        }
      }

      ajax.send(formData)
}

<?php

require_once "db.php";

$email = $_POST["email"];
$publicKey = $_POST["publicKey"];
$privateKey = $_POST["privateKey"];

$sql = "UPDATE users SET publicKey = ?, privateKey = ? WHERE email = ?";
$result = $conn->prepare($sql);
$result->execute([
  $publicKey,
  $privateKey,
  $email
]);

echo "Updated";
exit();

<form onsubmit="sendMessage()" id="form-message">
  <input type="email" name="sender" placeholder="Sender email" />
  <input type="email" name="receiver" placeholder="Receiver email" />
  <textarea name="message" placeholder="Message"></textarea>
  <input type="submit" value="Send" />
</form>

<script>
  let publicKey = ""
  let privateKey = ""
</script>

function sendMessage() {
  event.preventDefault()

  if (publicKey == "" || privateKey == "") {
    const form = event.target
    const formData = new FormData(form)
    
    const ajax = new XMLHttpRequest()
    ajax.open("POST", "get-keys.php", true)
    ajax.onreadystatechange = function () {
      if (this.readyState == 4 && this.status == 200) {
        const response = JSON.parse(this.responseText)
        privateKey = JSON.parse(response[0])
        publicKey = JSON.parse(response[1])
        doSendMessage()
      }
    }

    ajax.send(formData)
  } else {
    doSendMessage()
  }
}

<?php

require_once "db.php";

$sender = $_POST["sender"];
$receiver = $_POST["receiver"];

$sql = "SELECT privateKey FROM users WHERE email = ?";
$result = $conn->prepare($sql);
$result->execute([
  $sender
]);
$userSender = $result->fetchObject();

$sql = "SELECT publicKey FROM users WHERE email = ?";
$result = $conn->prepare($sql);
$result->execute([
  $receiver
]);
$userReceiver = $result->fetchObject();

echo json_encode([
  $userSender->privateKey,
  $userReceiver->publicKey
]);
exit();

async function doSendMessage() {
      const form = document.getElementById("form-message")
      const formData = new FormData()
      formData.append("sender", form.sender.value)
      formData.append("receiver", form.receiver.value)

      const publicKeyObj = await window.crypto.subtle.importKey(
          "jwk",
          publicKey,
          {
              name: "ECDH",
              namedCurve: "P-256",
          },
          true,
          []
      )

      const privateKeyObj = await window.crypto.subtle.importKey(
          "jwk",
          privateKey,
          {
              name: "ECDH",
              namedCurve: "P-256",
          },
          true,
          ["deriveKey", "deriveBits"]
      )

      const derivedKey = await window.crypto.subtle.deriveKey(
          { name: "ECDH", public: publicKeyObj },
          privateKeyObj,
          { name: "AES-GCM", length: 256 },
          true,
          ["encrypt", "decrypt"]
      )

      const encodedText = new TextEncoder().encode(form.message.value)
      const iv = new TextEncoder().encode(new Date().getTime())
      const encryptedData = await window.crypto.subtle.encrypt(
          { name: "AES-GCM", iv: iv },
          derivedKey,
          encodedText
      )
      const uintArray = new Uint8Array(encryptedData)
      const string = String.fromCharCode.apply(null, uintArray)
      const base64Data = btoa(string)
      const b64encodedIv = btoa(new TextDecoder("utf8").decode(iv))

      formData.append("message", base64Data)
      formData.append("iv", b64encodedIv)
  
      const ajax = new XMLHttpRequest()
      ajax.open("POST", "send-message.php", true)
      ajax.onreadystatechange = function () {
        if (this.readyState == 4 && this.status == 200) {
          console.log(this.responseText)
        }
      }

      ajax.send(formData)
}

<?php

require_once "db.php";

$sender = $_POST["sender"];
$receiver = $_POST["receiver"];
$message = $_POST["message"];
$iv = $_POST["iv"];

$sql = "INSERT INTO messages(sender, receiver, message, iv) VALUES (?, ?, ?, ?)";
$result = $conn->prepare($sql);
$result->execute([
  $sender,
  $receiver,
  $message,
  $iv
]);
echo $conn->lastInsertId();

<form onsubmit="readMessages()" id="form-read">
  <input type="email" name="sender" placeholder="Sender email" />
  <input type="email" name="receiver" placeholder="Receiver email" />
  <input type="submit" value="Read" />
</form>

function readMessages() {
  event.preventDefault()

  const form = event.target
  const formData = new FormData(form)
  
  const ajax = new XMLHttpRequest()
  ajax.open("POST", "get-messages.php", true)
  ajax.onreadystatechange = async function () {
    if (this.readyState == 4 && this.status == 200) {
      const response = JSON.parse(this.responseText)

      const publicKeyObj = await window.crypto.subtle.importKey(
          "jwk",
          JSON.parse(response.publicKey),
          {
              name: "ECDH",
              namedCurve: "P-256",
          },
          true,
          []
      )

      const privateKeyObj = await window.crypto.subtle.importKey(
          "jwk",
          JSON.parse(response.privateKey),
          {
              name: "ECDH",
              namedCurve: "P-256",
          },
          true,
          ["deriveKey", "deriveBits"]
      )

      const derivedKey = await window.crypto.subtle.deriveKey(
          { name: "ECDH", public: publicKeyObj },
          privateKeyObj,
          { name: "AES-GCM", length: 256 },
          true,
          ["encrypt", "decrypt"]
      )

      for (let a = 0; a < response.messages.length; a++) {
        const iv = new Uint8Array(atob(response.messages[a].iv).split("").map(function(c) {
            return c.charCodeAt(0)
        }))
        const initializationVector = new Uint8Array(iv).buffer
        const string = atob(response.messages[a].message)
        const uintArray = new Uint8Array(
            [...string].map((char) => char.charCodeAt(0))
        )
        const decryptedData = await window.crypto.subtle.decrypt(
            {
                name: "AES-GCM",
                iv: initializationVector,
            },
            derivedKey,
            uintArray
        )
        const message = new TextDecoder().decode(decryptedData)
        console.log(message)
      }
    }
  }

  ajax.send(formData)
}

<?php

require_once "db.php";

$sender = $_POST["sender"];
$receiver = $_POST["receiver"];

$sql = "SELECT * FROM messages WHERE sender = ? AND receiver = ?";
$result = $conn->prepare($sql);
$result->execute([
  $sender,
  $receiver
]);
$messages = $result->fetchAll(PDO::FETCH_OBJ);

$sql = "SELECT privateKey FROM users WHERE email = ?";
$result = $conn->prepare($sql);
$result->execute([
  $sender
]);
$userSender = $result->fetchObject();

$sql = "SELECT publicKey FROM users WHERE email = ?";
$result = $conn->prepare($sql);
$result->execute([
  $receiver
]);
$userReceiver = $result->fetchObject();

echo json_encode([
  "messages" => $messages,
  "privateKey" => $userSender->privateKey,
  "publicKey" => $userReceiver->publicKey
]);
exit();