diff --git a/libs/TOTP.php b/libs/TOTP.php
new file mode 100644
index 0000000..1ef0173
--- /dev/null
+++ b/libs/TOTP.php
@@ -0,0 +1,166 @@
+\n";
+
+ for ($currentWindow = -$window; $currentWindow <= $window; $currentWindow++) {
+ $time = $timeSlice + $currentWindow;
+ $generatedCode = generateTOTP($secret, $digits, $time);
+ #echo "$time $generatedCode
\n";
+
+ if ($generatedCode === $enteredCodeInt) {
+ return true; // Code is valid within the window
+ }
+ }
+
+ return false; // Code is not valid
+}
+
+function generateTOTP($secret, $digits = 6, $timeSlice = null) {
+ if ($timeSlice === null) {
+ $timeSlice = floor(time() / 30);
+ }
+
+ $secret = base32Decode($secret);
+ $timeSlice = pack('N*', 0) . pack('N*', $timeSlice);
+
+ $hash = hash_hmac('sha1', $timeSlice, $secret, true);
+ $offset = ord($hash[19]) & 0xf;
+
+ $otp = (
+ (ord($hash[$offset + 0]) & 0x7f) << 24 |
+ (ord($hash[$offset + 1]) & 0xff) << 16 |
+ (ord($hash[$offset + 2]) & 0xff) << 8 |
+ (ord($hash[$offset + 3]) & 0xff)
+ );
+
+ #var_dump($otp);
+ #echo "
\n";
+
+ // When digits is 10, the padding was giving a wrong OTP
+ // Just return the calculated value
+ if ($digits === 10) {
+ return $otp;
+ }
+
+ $otp = $otp % pow(10, $digits);
+ return str_pad($otp, $digits, '0', STR_PAD_LEFT);
+}
+
+function base32Decode($base32) {
+ $base32chars = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ234567';
+ $base32charsFlipped = array_flip(str_split($base32chars));
+ $paddingChar = '=';
+ $paddingCharCount = 0;
+
+ if (strpos($base32, $paddingChar) !== false) {
+ $paddingCharCount = substr_count($base32, $paddingChar);
+ }
+
+ $allowedValues = array(6, 4, 3, 1, 0);
+
+ if (!in_array($paddingCharCount, $allowedValues)) {
+ return false;
+ }
+
+ for ($i = 0; $i < 4; ++$i) {
+ if ($paddingCharCount == $allowedValues[$i] &&
+ substr($base32, -$allowedValues[$i]) != str_repeat($paddingChar, $allowedValues[$i])
+ ) {
+ return false;
+ }
+ }
+
+ $base32 = str_replace($paddingChar, '', $base32);
+ $base32 = str_split($base32);
+ $binaryString = '';
+
+ foreach ($base32 as $char) {
+ if (!isset($base32charsFlipped[$char])) {
+ return false; // Invalid character found
+ }
+ $binaryString .= sprintf('%05b', $base32charsFlipped[$char]);
+ }
+
+ $length = strlen($binaryString);
+ $offset = 0;
+ $binaryData = '';
+
+ while ($offset < $length) {
+ $binaryChunk = substr($binaryString, $offset, 8);
+
+ if (strlen($binaryChunk) < 8) {
+ $binaryChunk = str_pad($binaryChunk, 8, '0', STR_PAD_RIGHT);
+ }
+
+ $decimalChunk = bindec($binaryChunk);
+ $binaryData .= pack('C', $decimalChunk);
+ $offset += 8;
+ }
+
+ return $binaryData;
+}
+
+function base32Encode($input) {
+ $base32Chars = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ234567';
+ $base32String = '';
+ $position = 0;
+ $carry = 0;
+ foreach (str_split($input) as $byte) {
+ $carry |= ord($byte) << $position;
+ $position += 8;
+ while ($position >= 5) {
+ $base32String .= $base32Chars[$carry & 31];
+ $carry >>= 5;
+ $position -= 5;
+ }
+ }
+ if ($position > 0) {
+ if ($carry & 31) {
+ $base32String .= $base32Chars[$carry & 31];
+ }
+ }
+ return $base32String;
+}
+
+function generateRandomSecret($length = 32) {
+ // https://medium.com/@nicola88/two-factor-authentication-with-totp-ccc5f828b6df
+ $bytes = random_bytes($length);
+ $base32 = base32Encode($bytes);
+
+ return substr($base32, 0, $length);
+}
+
+# Examples of usage (To move somewhere else)
+/*
+$randomSecret = generateRandomSecret();
+echo "Random Secret Key: $randomSecret
\n";
+
+$secret = 'K3OBZ7XPR6T4PTNXSNCQ';
+$enteredCode = '123456';
+$digits = 6;
+if (isset($_GET['c']) && isset($_GET['s'])) {
+ $enteredCode = $_GET['c'];
+ $secret = $_GET['s'];
+ $isCodeValid = verifyTOTP($secret, $digits, $enteredCode);
+
+ if ($isCodeValid) {
+ echo "Code $enteredCode is valid!
";
+ } else {
+ echo "Code $enteredCode is invalid!
";
+ }
+}
+
+$code = generateTOTP($secret);
+echo "TOTP code: $code
\n";
+
+$code = generateTOTP($secret, 8);
+echo "TOTP code: $code
\n";
+*/
diff --git a/libs/session.php b/libs/session.php
index 28ffa4a..bb9f9fc 100644
--- a/libs/session.php
+++ b/libs/session.php
@@ -1,18 +1,30 @@
-
+