How to Virus Scan File Uploads & Block Invalid Files using C/C++

Combining virus, malware and content threat protection policies into a single, comprehensive security solution makes it easy to provide multi-threat protection for multiple applications handling file uploads & downloads.

You can use the below code to accomplish exactly that. This code will help structure an API request to scan files for millions of virus and malware signatures, and it allows you to set custom threat rules against unwanted file extensions and file content types in the request body.

Invalid files can be considered any file content that does NOT match its file extension; setting the “allowInvalidFiles” parameter to “false” will block invalid file uploads with in-depth content verification.

First install libcurl into your C/C++ project:

libcurl/7.75.0

Next, use the below code examples to structure your API call:

CURL *curl;
CURLcode res;
curl = curl_easy_init();
if(curl) {
     curl_easy_setopt(curl, CURLOPT_CUSTOMREQUEST, "POST");
     curl_easy_setopt(curl, CURLOPT_URL, "https://api.cloudmersive.com/virus/scan/file/advanced");
     curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1L);
     curl_easy_setopt(curl, CURLOPT_DEFAULT_PROTOCOL, "https");
     struct curl_slist *headers = NULL;
     headers = curl_slist_append(headers, "allowExecutables: <boolean>");
     headers = curl_slist_append(headers, "allowInvalidFiles: <boolean>");
     headers = curl_slist_append(headers, "allowScripts: <boolean>");
     headers = curl_slist_append(headers, "allowPasswordProtectedFiles: <boolean>");
     headers = curl_slist_append(headers, "allowMacros: <boolean>");
     headers = curl_slist_append(headers, "allowXmlExternalEntities: <boolean>");
     headers = curl_slist_append(headers, "allowInsecureDeserialization: <boolean>");
     headers = curl_slist_append(headers, "allowHtml: <boolean>");
     headers = curl_slist_append(headers, "restrictFileTypes: <string>");
     headers = curl_slist_append(headers, "Content-Type: multipart/form-data");
     headers = curl_slist_append(headers, "Apikey: YOUR-API-KEY-HERE");
     curl_easy_setopt(curl, CURLOPT_HTTPHEADER, headers);
     curl_mime *mime;
     curl_mimepart *part;
     mime = curl_mime_init(curl);
     part = curl_mime_addpart(mime);
     curl_mime_name(part, "inputFile");
     curl_mime_filedata(part, "/path/to/file");
     curl_easy_setopt(curl, CURLOPT_MIMEPOST, mime);
     res = curl_easy_perform(curl);
     curl_mime_free(mime);
}
curl_easy_cleanup(curl);

Provide a free-tier API key to satisfy the authorization header (this allows up to 800 API calls per month), and you’re all set. Easy!