CURLINFO_HTTPAUTH_USED(3) Library Functions Manual CURLINFO_HTTPAUTH_USED(3)

CURLINFO_HTTPAUTH_USED - get used HTTP authentication method

#include <curl/curl.h>
CURLcode curl_easy_getinfo(CURL *handle, CURLINFO_HTTPAUTH_USED, long *authp);

Pass a pointer to a long to receive a bitmask indicating the authentication method that was used in the previous HTTP request. The meaning of the possible bits is explained in the CURLOPT_HTTPAUTH(3) option for curl_easy_setopt(3).

The returned value has zero or one bit set.

This functionality affects http only

int main(void)
{
  CURL *curl = curl_easy_init();
  if(curl) {
    CURLcode res;
    curl_easy_setopt(curl, CURLOPT_URL, "https://example.com");
    curl_easy_setopt(curl, CURLOPT_HTTPAUTH, CURLAUTH_BASIC | CURLAUTH_DIGEST);
    curl_easy_setopt(curl, CURLOPT_USERNAME, "shrek");
    curl_easy_setopt(curl, CURLOPT_PASSWORD, "swamp");
    res = curl_easy_perform(curl);
    if(!res) {
      long auth;
      res = curl_easy_getinfo(curl, CURLINFO_HTTPAUTH_USED, &auth);
      if(!res) {
        if(!auth)
          printf("No auth used\n");
        else {
          if(auth == CURLAUTH_DIGEST)
            printf("Used Digest authentication\n");
          else
            printf("Used Basic authentication\n");
        }
      }
    }
    curl_easy_cleanup(curl);
  }
}

Added in curl 8.12.0

curl_easy_getinfo(3) returns a CURLcode indicating success or error.

CURLE_OK (0) means everything was OK, non-zero means an error occurred, see libcurl-errors(3).

CURLINFO_HTTPAUTH_AVAIL(3), CURLINFO_PROXYAUTH_USED(3), CURLOPT_HTTPAUTH(3)

2025-02-13 libcurl