fix: limit to portal2.sr domain

Author: ThisAMJ

src/Features/ConfigPlus.cpp

@@ -13,6 +13,7 @@
 #include <unordered_set>
 #include <fstream>
 #include <curl/curl.h>
+#include <regex>
 
 // Fuck you Windows
 #ifdef _WIN32
@@ -60,6 +61,14 @@ CON_COMMAND_F(sar_download_file, "sar_download_file <url> <filepath> [directory]
 	}
 	if (!args[1][0] || !args[2][0]) return console->Print(sar_download_file.ThisPtr()->m_pszHelpString);
 
+	std::string domain = std::regex_replace(args[1], std::regex("^.*://([^/?:]+)/?.*$"), "$1");
+
+	if (!strcmp(domain.c_str(), args[1])) return console->Print("Invalid URL.\n"); // URL is missing protocol. Reject.
+
+	if (domain.length() < 10 || !!strcmp(domain.c_str() + domain.length() - 10, "portal2.sr")) {
+		return console->Print("URL domain is not portal2.sr.\n");
+	}
+
 	std::string filepath = args[2];
 	std::string gamedir = "";