---
name: "CURLINFO_HTTPAUTH_USED"
section: "3"
platform: "linux"
package: "curl"
version: "8.23.0-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/CURLINFO_HTTPAUTH_USED"
---

# CURLINFO\_HTTPAUTH\_USED(3)

used HTTP authentication method

## NAME

CURLINFO\_HTTPAUTH\_USED - used HTTP authentication method

## SYNOPSIS

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

## DESCRIPTION

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)](/CURLOPT_HTTPAUTH/3.md)* option for *[curl\_easy\_setopt(3)](/curl_easy_setopt/3.md)*.

The returned value has zero or one bit set.

## PROTOCOLS

This functionality affects http only

## EXAMPLE

```
int main(void)
{
  CURL *curl = curl_easy_init();
  if(curl) {
    CURLcode result;
    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");
    result = curl_easy_perform(curl);
    if(result == CURLE_OK) {
      long auth;
      result = curl_easy_getinfo(curl, CURLINFO_HTTPAUTH_USED, &auth);
      if(result == CURLE_OK) {
        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);
  }
}
```

## AVAILABILITY

Added in curl 8.12.0

## RETURN VALUE

*[curl\_easy\_getinfo(3)](/curl_easy_getinfo/3.md)* returns a CURLcode indicating success or error.

CURLE\_OK (0) means everything was OK, non-zero means an error occurred, see *[libcurl-errors(3)](/libcurl-errors/3.md)*.

## SEE ALSO

[**CURLINFO\_HTTPAUTH\_AVAIL**(3)](/CURLINFO_HTTPAUTH_AVAIL/3.md), [**CURLINFO\_PROXYAUTH\_USED**(3)](/CURLINFO_PROXYAUTH_USED/3.md), [**CURLOPT\_HTTPAUTH**(3)](/CURLOPT_HTTPAUTH/3.md)