add basic URL validation for all modes

CMakeLists.txt

@@ -1,7 +1,7 @@
 cmake_minimum_required(VERSION 3.5)
 project(shortener_bot LANGUAGES C CXX)
 
-add_executable(bot main.cpp telegram_client.cpp commands.cpp)
+add_executable(bot main.cpp telegram_client.cpp commands.cpp util.cpp)
 set_property(TARGET bot PROPERTY CXX_STANDARD 20)
 set_property(TARGET bot PROPERTY CXX_STANDARD_REQUIRED ON)
 

commands.cpp

@@ -4,6 +4,7 @@
 #include "curl/easy.h"
 #include "td/telegram/td_api.h"
 #include "td/tl/TlObject.h"
+#include "util.h"
 #include <cstring>
 #include <functional>
 #include <random>
@@ -14,6 +15,8 @@
 #include <utility>
 #include <vector>
 
+void send_help_msg(context *ctx, td_api::message &msg);
+
 void cmd::handle_regular_message(context *ctx, td_api::message &msg) {
   if (msg.content_->get_id() == td_api::messageText::ID) {
     std::string text = static_cast<td_api::messageText&>(*msg.content_).text_->text_;
@@ -24,7 +27,11 @@ void cmd::handle_regular_message(context *ctx, td_api::message &msg) {
         param.remove_suffix(param.size() - nextSpace);
       spdlog::info("Command /shorten received with parameter '{}'", param);
 
-      // TODO check URL validity
+      std::string paramStr(param);
+      if (!url::is_url_valid(paramStr)) {
+        send_help_msg(ctx, msg);
+	return;
+      }
 
       bool result = shorten_link(std::string(param), ctx, [tg = ctx->tg, chat_id = msg.chat_id_, thread_id = msg.message_thread_id_](std::string url){
         tg->send_query(td_api::make_object<td_api::sendMessage>(
@@ -49,22 +56,17 @@ void cmd::handle_regular_message(context *ctx, td_api::message &msg) {
         ), {});
       }
     } else if (std::strncmp(text.c_str(), "/shorten", 8) == 0) {
-      std::string textRaw("usage: /shorten <url>");
-      std::vector<td_api::object_ptr<td_api::textEntity>> empty;
-      auto text = static_cast<td_api::object_ptr<td_api::InputMessageContent>>(td_api::make_object<td_api::inputMessageText>(td_api::make_object<td_api::formattedText>(textRaw, std::move(empty)), nullptr, false));
-      ctx->tg->send_query(td_api::make_object<td_api::sendMessage>(msg.chat_id_, msg.message_thread_id_, nullptr, nullptr, nullptr, std::move(text)), {});
+      send_help_msg(ctx, msg);
     }
   }
 }
 
 void cmd::handle_inline_query(context *ctx, td_api::updateNewInlineQuery &query) {
-  // TODO check URL validity
-
+  std::vector<td_api::object_ptr<td_api::InputInlineQueryResult>> results;
+  if (url::is_url_valid(query.query_)) {
     uint64_t pendingQueryId = new_pending_query_id();
     ctx->inlineQueries.insert(std::pair<uint64_t, pending_inline_query>(pendingQueryId, {query.query_, std::chrono::steady_clock::now() + std::chrono::hours(5)}));
 
-  std::vector<td_api::object_ptr<td_api::InputInlineQueryResult>> results;
-  results.reserve(1);
     auto messageButton = td_api::make_object<td_api::inlineKeyboardButton>(
       "press to shorten",
       static_cast<td_api::object_ptr<td_api::InlineKeyboardButtonType>>(td_api::make_object<td_api::inlineKeyboardButtonTypeCallback>(std::to_string(pendingQueryId)))
@@ -96,6 +98,7 @@ void cmd::handle_inline_query(context *ctx, td_api::updateNewInlineQuery &query)
         false // clear_draft
       ))
     )));
+  }
   ctx->tg->send_query(td_api::make_object<td_api::answerInlineQuery>(
     query.id_,
     false, // is_personal
@@ -185,6 +188,13 @@ bool cmd::shorten_link(std::string link, context *ctx, std::function<void(std::s
   return r == CURLM_OK;
 }
 
+void send_help_msg(context *ctx, td_api::message &msg) {
+  std::string textRaw("usage: /shorten <url>");
+  std::vector<td_api::object_ptr<td_api::textEntity>> empty;
+  auto text = static_cast<td_api::object_ptr<td_api::InputMessageContent>>(td_api::make_object<td_api::inputMessageText>(td_api::make_object<td_api::formattedText>(textRaw, std::move(empty)), nullptr, false));
+  ctx->tg->send_query(td_api::make_object<td_api::sendMessage>(msg.chat_id_, msg.message_thread_id_, nullptr, nullptr, nullptr, std::move(text)), {});
+}
+
 uint64_t cmd::new_pending_query_id() {
   static std::mt19937 rng;
   static std::uniform_int_distribution<uint64_t> dist(0, 0xFFFFFFFFFFFFFFFFULL);

util.cpp

@@ -0,0 +1,7 @@
+#include "util.h"
+#include <regex>
+
+bool url::is_url_valid(std::string &url) {                          static std::regex r("https?:\\/\\/[-a-zA-Z0-9@:%._\\+~#=]{1,256}\\.[a-zA-Z0-9()]{1,6}\\b([-a-zA-Z0-9()@:%_\\+.~#?&//=]*)");
+    std::cmatch m;
+    return std::regex_match(url.c_str(), m, r);
+}

util.h

@@ -0,0 +1,6 @@
+#pragma once
+#include <string>
+
+namespace url {
+    bool is_url_valid(std::string &url);
+}