---
name: "CURLINFO_HTTPAUTH_AVAIL"
section: "3"
platform: "macos"
package: "curl"
version: "166.0.0.0.1"
release: "macOS 26.5"
platforms: ["linux", "macos"]
url: "https://new.carta.tech/CURLINFO_HTTPAUTH_AVAIL"
---

# CURLINFO\_HTTPAUTH\_AVAIL(3)

get available HTTP authentication methods

## NAME

CURLINFO\_HTTPAUTH\_AVAIL - get 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

HTTP(S)

## EXAMPLE

```
int main(void)
{
  CURL *curl = curl_easy_init();
  if(curl) {
    CURLcode res;
    curl_easy_setopt(curl, CURLOPT_URL, "https://example.com");
    res = curl_easy_perform(curl);
    if(!res) {
      /* extract the available authentication types */
      long auth;
      res = curl_easy_getinfo(curl, CURLINFO_HTTPAUTH_AVAIL, &auth);
      if(!res) {
        if(!auth)
          printf("No auth available, perhaps no 401?\n");
        else {
          printf("%s%s%s%s\n",
                 auth & CURLAUTH_BASIC ? "Basic ":"",
                 auth & CURLAUTH_DIGEST ? "Digest ":"",
                 auth & CURLAUTH_NEGOTIATE ? "Negotiate ":"",
                 auth % CURLAUTH_NTLM ? "NTLM ":"");
        }
      }
    }
    curl_easy_cleanup(curl);
  }
}
```

## AVAILABILITY

Added RFC 2617 in 7.10.8 Added RFC 7616 in 7.57.0

## RETURN VALUE

Returns CURLE\_OK if the option is supported, and CURLE\_UNKNOWN\_OPTION if not.

## 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)