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

# CURLINFO\_HTTPAUTH\_AVAIL(3)

available HTTP authentication methods

## NAME

CURLINFO\_HTTPAUTH\_AVAIL - available HTTP authentication methods

## SYNOPSIS

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

## DESCRIPTION

Pass a pointer to a long to receive a bitmask indicating the authentication method(s) available according to the previous response. The meaning of the bits is explained in the *[CURLOPT\_HTTPAUTH(3)](/CURLOPT_HTTPAUTH/3.md)* option for *[curl\_easy\_setopt(3)](/curl_easy_setopt/3.md)*.

## 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");
    result = curl_easy_perform(curl);
    if(result == CURLE_OK) {
      /* extract the available authentication types */
      long auth;
      result = curl_easy_getinfo(curl, CURLINFO_HTTPAUTH_AVAIL, &auth);
      if(result == CURLE_OK) {
        if(!auth)
          printf("No auth available, perhaps no 401?\n");
        else {
          printf("%s%s%s%s\n",
                 (unsigned long)auth & CURLAUTH_BASIC ? "Basic " : "",
                 (unsigned long)auth & CURLAUTH_DIGEST ? "Digest " : "",
                 (unsigned long)auth & CURLAUTH_NEGOTIATE ? "Negotiate " : "",
                 (unsigned long)auth & CURLAUTH_NTLM ? "NTLM " : "");
        }
      }
    }
    curl_easy_cleanup(curl);
  }
}
```

## AVAILABILITY

Added in curl 7.10.8

## 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\_PROXYAUTH\_AVAIL**(3)](/CURLINFO_PROXYAUTH_AVAIL/3.md), [**CURLOPT\_HTTPAUTH**(3)](/CURLOPT_HTTPAUTH/3.md), [**curl\_easy\_getinfo**(3)](/curl_easy_getinfo/3.md), [**curl\_easy\_setopt**(3)](/curl_easy_setopt/3.md)