CURLINFO\_PROXYAUTH\_USED(3) Library Functions Manual CURLINFO\_PROXYAUTH\_USED(3)

# [NAME](#NAME)

CURLINFO\_PROXYAUTH\_USED - HTTP proxy authentication method

# [SYNOPSIS](#SYNOPSIS)

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

# [DESCRIPTION](#DESCRIPTION)

Pass a pointer to a long to receive a bitmask indicating the authentication method that was used in the previous request done over an HTTP proxy. The meaning of the possible 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).

The returned value has zero or one bit set.

# [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");


    curl_easy_setopt(curl, CURLOPT_PROXY, "http://proxy.example");


    curl_easy_setopt(curl, CURLOPT_PROXYAUTH,


                     CURLAUTH_BASIC | CURLAUTH_DIGEST);


    curl_easy_setopt(curl, CURLOPT_PROXYUSERNAME, "shrek");


    curl_easy_setopt(curl, CURLOPT_PROXYPASSWORD, "swamp");


    result = curl_easy_perform(curl);


    if(result == CURLE_OK) {


      long auth;


      result = curl_easy_getinfo(curl, CURLINFO_PROXYAUTH_USED, &auth);


      if(result == CURLE_OK) {


        if(!auth)


          printf("No auth used\n");


        else {


          if(auth == CURLAUTH_DIGEST)


            printf("Used Digest proxy authentication\n");


          else


            printf("Used Basic proxy authentication\n");


        }


      }


    }


    curl_easy_cleanup(curl);


  }
}
```

# [AVAILABILITY](#AVAILABILITY)

Added in curl 8.12.0

# [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\_HTTPAUTH\_USED**(3)](/man/os/curl/CURLINFO_HTTPAUTH_USED.3), [**CURLINFO\_PROXYAUTH\_AVAIL**(3)](/man/os/curl/CURLINFO_PROXYAUTH_AVAIL.3), [**CURLOPT\_HTTPAUTH**(3)](/man/os/curl/CURLOPT_HTTPAUTH.3)

2026-10-01 libcurl

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Document: CURLINFO_PROXYAUTH_USED(3) from curl 8.22.0-r4 (Chainguard OS)
Source: https://github.com/curl/curl.git