OAuth2 Saved Login Session Mechanism

secret/rsa.php

@@ -38,6 +38,26 @@ function getFingerprint() {
     return $fingerprint;
 }
 
+// Object -> JSON -> Base84 -> Split -> Encrypt -> Combined -> re-base64 -> Sent
+
+function encryptPayload($input){
+    $holdingArray = str_split(base64_encode($input), 64);
+    $holdingArray = array_map(function($value){
+        return encrypt($value);
+    }, $holdingArray);
+    $holdingArray = implode("%", $holdingArray);
+    return $holdingArray;
+}
+
+function decryptPayload($input){
+    $holdingArray = explode("%", $input);
+    $holdingArray = array_map(function($value){
+        return decrypt($value);
+    }, $holdingArray);
+    $holdingArray = implode("", $holdingArray);
+    return base64_decode($holdingArray);
+}
+
 function encrypt($input){
     // Encrypt with public key
     ensureKey();
@@ -61,4 +81,56 @@ function decrypt($input){
     return $decrypted;
 }
 
+function buildEncToken($AuthToken, $UserID, $UserIP, $UserAgent ){
+    // Token Data:
+    //  - HTown AuthToken
+    //  - UserID
+    //  - UserIP
+    //  - UserAgent
+    //  - Timestamp
+    $TokenData = array(
+        "AuthToken" => $AuthToken,
+        "UserID" => $UserID,
+        "UserIP" => $UserIP,
+        "UserAgent" => $UserAgent,
+        "Timestamp" => time() // Unix Time in Seconds
+    );
+    $TokenData = json_encode($TokenData);
+    $EncTokenData = encryptPayload($TokenData);
+    return $EncTokenData;
+}
+
+function verifyEncToken($EncTokenData){
+    $TokenData = decryptPayload($EncTokenData);
+    $TokenData = json_decode($TokenData);
+    if ($TokenData != null && isset($TokenData->AuthToken) && isset($TokenData->UserID) && isset($TokenData->UserIP) && isset($TokenData->UserAgent) && isset($TokenData->Timestamp)) {
+        // Valid Token
+        if (time() - $TokenData->Timestamp > 900) { // 15-minute max login session
+            // Token Expired
+            return "Login Expired";
+        }
+        if ($TokenData->UserIP != $_SERVER["REMOTE_ADDR"]) {
+            // IP Mismatch
+            return "IP Mismatch";
+        }
+        if ($TokenData->UserAgent != $_SERVER["HTTP_USER_AGENT"]) {
+            // User Agent Mismatch
+            return "UserAgent Mismatch";
+        }
+        $credentialResults = verifyCredentials($TokenData->AuthToken);
+        if (gettype($credentialResults) == "string") {
+            // Invalid AuthToken
+            return "Invalid Mastodon Account";
+        }
+        return array(
+            "AuthToken" => $TokenData->AuthToken,
+            "UserID" => $TokenData->UserID,
+            "MastodonData" => $credentialResults
+        );
+    }else{
+        // Invalid Token
+        return "Invalid Token";
+    }
+}
+
 ?>