initial commit to enable token validation and key download

public/TokenManager.php

@@ -8,7 +8,8 @@ class TokenManager {
     /*
      * VARIABLES
      */
-    private string $storagePath; // Subdirectory under Tresor's /private directory to use to store all the token information
+    private string $tokenStoragePath; // Subdirectory under Tresor's /public directory to use to store all the token information
+    private string $keyStoragePath;   // Subdirectory under Tresor's /private directory to store all keyfiles
     private int $expireDays;     // number of dates for a token to expire
     private int $maxDownloads;   // maximum number of downloads before a token becomes invalid
     private int $tokenLength;    // number of random bytes to use to create the token name
@@ -19,34 +20,44 @@ class TokenManager {
      */
 
     // initialize the token instance in PHP
-    public __contruct(
+    public function __construct(
         string $storagePath = '/tokens',
-        int $exireDays = 1,
+        string $keyStoragePath = '/keys',
+        int $expireDays = 1,
         int $maxDownloads = 1,
         int $tokenLength = 32
     ) {
-        $this->storagePath = $storagePath;
-        $this->$expireDays = $expireDays;
-        $this->$maxDownloads = $maxDownloads;
-        $this->$tokenLength = $tokenLength;
+        $this->tokenStoragePath = __DIR__ . $storagePath;
+        $this->keyStoragePath = substr(__DIR__, 0, strrpos(__DIR__, '/') + 1) . 'private' . $keyStoragePath;
+        $this->expireDays = $expireDays;
+        $this->maxDownloads = $maxDownloads;
+        $this->tokenLength = $tokenLength;
+
+        if(!is_dir($this->tokenStoragePath))
+            mkdir($this->tokenStoragePath, 0755, true);
     }
 
     // generate a new token and save it to the file system
-    public generateToken(
+    public function generateToken(
         string $filename,
         string $ownerName,
         string $allowedUser
     ) {
-        return (['error'=>'no token generated', 'status'=>'500']);
+        return (['error'=>'no token generated', 'status'=>500]);
     }
 
     // retrieve/download the key file connected with the token
-    public retrieveToken(string $tokenName) {
+    public function retrieveToken(string $tokenName) {
+	$result = $this->validateToken($tokenName);
+        if(!isset($result['success']))
+            return ['error'=>'token invalid', 'status'=>422];
 
+        // send the file name of the designated key for download
+        return ['success'=>$result['success'], 'status'=>200];
     }
 
     // check a token and remove it when it's expired
-    public cleanupToken(string $tokenName) {
+    public function cleanupToken(string $tokenName) {
 
     }
 
@@ -55,12 +66,49 @@ class TokenManager {
      */
     
     // check whether a token is still valid and accessible by the user requesting it
-    private validateToken($tokenName) {
-        return null;
+    private function validateToken($tokenName) {
+        // check if tokenName is a valid hexadecimal string
+        if(!ctype_xdigit($tokenName))
+             return false;
+
+        // check if token file exists and read data if so
+        $tokenPath = $this->getTokenFilePath($tokenName);
+        if(!file_exists($tokenPath))
+            return false;
+        $tokenData = json_decode(file_get_contents($tokenPath));
+
+        // check expiry of the token
+        if( new DateTime() > new DateTime($tokenData->expires))
+            return false;
+
+        // safety-check if requesting user name is matching the allowed characters (a-zA-Z0-9)
+        if(preg_match('/[^a-zA-Z0-9]/', $_SERVER['PHP_AUTH_USER']))
+            return false;
+        // check if the requesting user is allowed to query the token
+        if(levenshtein($_SERVER['PHP_AUTH_USER'], $tokenData->allowedUser))
+            return false;
+        // check if requesting user is allowed to retrieve the key
+        $allowedUsersFilePath = __DIR__ . '/../private/keys/allowedUsers.json';
+        if(!file_exists($allowedUsersFilePath))
+            return false;
+        $allowedUsers = json_decode(file_get_contents($allowedUsersFilePath))->{$tokenData->owner}->{$tokenData->file};
+        if(array_search($_SERVER['PHP_AUTH_USER'], $allowedUsers, true) === false)
+            return false;
+
+        //all checks completed successfully
+        $path = substr( __DIR__, 0, strrpos(__DIR__, '/') + 1 );
+        return ['success'=>$this->keyStoragePath . '/' . $tokenData->owner . '/' . $tokenData->file, 'status'=>200];
     }
 
-    private getDownloadFileInfo ($tokenName) {
+    private function getDownloadFileInfo ($tokenName) {
         $fileInfo = [];
         return null;
     }
-}
+
+    private function getTokenFilePath($tokenName) {
+        $filePath = $this->tokenStoragePath . '/' . $tokenName . '.json';
+        if(!file_exists($filePath))
+            return false;
+        return $filePath;
+    }
+}