Fix memory leaks and improve error handling in req() function

1. Added curl_easy_cleanup(curl); to free resources after request
2. Changed to 2L (Enforces full hostname verification)
3. Added cleanup before calling error()
4. Properly convert to C-string XorStr("keyauth.win").c_str()
5. Proper Cleanup to Avoid Memory Leaks

Your original function doesn’t call curl_easy_cleanup(), which means CURL resources aren’t freed in case of errors.
this leads to memory leaks if the function is called multiple times (and its already called multiple times) almost every function 
in keyAuth library use it.

Stronger SSL Security curl_easy_setopt(curl, CURLOPT_SSL_VERIFYHOST, 1); only checks if the SSL certificate exists, 
but does not verify the hostname properly.
Change it to curl_easy_setopt(curl, CURLOPT_SSL_VERIFYHOST, 2L);
Enforces full hostname verification, preventing MITM attacks

Author: SaSukiTB

auth.cpp

@@ -1664,40 +1664,41 @@ void KeyAuth::api::setDebug(bool value) {
     KeyAuth::api::debug = value;
 }
 
-std::string KeyAuth::api::req(std::string data, std::string url) {
+std::string KeyAuth::api::req(const std::string& data, const std::string& url) {
+
     CURL* curl = curl_easy_init();
-    if (!curl)
-        return XorStr("null");
+    if (!curl) {
+        error(XorStr("CURL Initialization Failed!"));
+    }
 
     std::string to_return;
     std::string headers;
 
+    // Set CURL options
     curl_easy_setopt(curl, CURLOPT_URL, url.c_str());
-
-    curl_easy_setopt(curl, CURLOPT_SSL_VERIFYHOST, 1);
-    
-    curl_easy_setopt(curl, CURLOPT_NOPROXY, XorStr( "keyauth.win" ) );
-    
+    curl_easy_setopt(curl, CURLOPT_SSL_VERIFYHOST, 2L);
     curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, 1L);
     curl_easy_setopt(curl, CURLOPT_CERTINFO, 1L);
-
+    curl_easy_setopt(curl, CURLOPT_NOPROXY, XorStr("keyauth.win").c_str());
     curl_easy_setopt(curl, CURLOPT_POSTFIELDS, data.c_str());
-
     curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, write_callback);
     curl_easy_setopt(curl, CURLOPT_WRITEDATA, &to_return);
-
     curl_easy_setopt(curl, CURLOPT_HEADERFUNCTION, header_callback);
     curl_easy_setopt(curl, CURLOPT_HEADERDATA, &headers);
 
-    auto code = curl_easy_perform(curl);
-
-    if (code != CURLE_OK)
-        error(curl_easy_strerror(code));
+    // Perform the request
+    CURLcode code = curl_easy_perform(curl);
+    if (code != CURLE_OK) {
+        std::string errorMsg = "CURL Error: " + std::string(curl_easy_strerror(code));
+        curl_easy_cleanup(curl);  
+        error(errorMsg);
+    }
 
     debugInfo(data, url, to_return, "Sig: " + signature + "\nTimestamp:" + signatureTimestamp);
-
+    curl_easy_cleanup(curl); 
     return to_return;
 }
+
 void error(std::string message) {
     system((XorStr("start cmd /C \"color b && title Error && echo ").c_str() + message + XorStr(" && timeout /t 5\"")).c_str());
     LI_FN(__fastfail)(0);