Sending an HTTP request with basic authentication

Sending an HTTP request with basic authentication

How to:

Here’s a basic example using the CURL library in C++. Before diving in, make sure you’ve got libcurl installed.

#include <iostream>
#include <curl/curl.h>

// Simple callback function to handle data received by curl
static size_t WriteCallback(void *contents, size_t size, size_t nmemb, void *userp) {
    ((std::string*)userp)->append((char*)contents, size * nmemb);
    return size * nmemb;

int main() {
    CURL *curl;
    CURLcode res;
    std::string readBuffer;

    curl = curl_easy_init();
    if(curl) {
        curl_easy_setopt(curl, CURLOPT_URL, "");
        curl_easy_setopt(curl, CURLOPT_HTTPAUTH, CURLAUTH_BASIC);
        curl_easy_setopt(curl, CURLOPT_USERNAME, "user");
        curl_easy_setopt(curl, CURLOPT_PASSWORD, "pass");
        curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, WriteCallback);
        curl_easy_setopt(curl, CURLOPT_WRITEDATA, &readBuffer);
        // Perform the request, and check for errors
        res = curl_easy_perform(curl);
        if(res != CURLE_OK) {
            fprintf(stderr, "curl_easy_perform() failed: %s\n", curl_easy_strerror(res));
        } else {
            std::cout << readBuffer << std::endl;
        // Cleanup
    return 0;

You’ll see a response from the server printed to the console, assuming no errors occurred.

Deep Dive

Basic authentication is old-school, dating back to the early days of HTTP. Now, industry preference leans towards more secure methods like OAuth and tokens. Despite this, basic auth remains in use, often for internal or simple systems where heavy security layers are bulky overkill.

Under the hood, your username and password are base64-encoded and tucked into the HTTP header. It’s simple yet insecure if not over HTTPS because base64 is easily reversible—making HTTPS a must.

If libcurl isn’t to your taste, consider alternatives like the cpp-httplib library, or you can run with Boost.Beast for a more hands-on approach.

See Also