CURLINFO\_HTTPAUTH\_AVAIL(3) Library Functions Manual CURLINFO\_HTTPAUTH\_AVAIL(3)

# [NAME](#NAME)

CURLINFO\_HTTPAUTH\_AVAIL - available HTTP authentication methods

# [SYNOPSIS](#SYNOPSIS)

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

# [DESCRIPTION](#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)*](/man/os/curl/CURLOPT_HTTPAUTH.3) option for [*curl\_easy\_setopt(3)*](/man/os/curl/curl_easy_setopt.3).

# [PROTOCOLS](#PROTOCOLS)

This functionality affects http only

# [EXAMPLE](#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](#AVAILABILITY)

Added in curl 7.10.8

# [RETURN VALUE](#RETURN_VALUE)

[*curl\_easy\_getinfo(3)*](/man/os/curl/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)*](/man/os/curl/libcurl-errors.3).

# [SEE ALSO](#SEE_ALSO)

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

2026-10-14 libcurl

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Document: CURLINFO_HTTPAUTH_AVAIL(3) from curl 8.23.0-r0 (Chainguard OS)
Source: https://github.com/curl/curl.git