NAME

       CURLOPT_HTTPAUTH - HTTP server authentication methods to try

SYNOPSIS

       #include <curl/curl.h>

       CURLcode curl_easy_setopt(CURL *handle, CURLOPT_HTTPAUTH, long bitmask);

DESCRIPTION

       Pass  a long as parameter, which is set to a bitmask, to tell libcurl which authentication
       method(s) you want it to use speaking to the remote server.

       The available bits are listed below. If more than one bit is set,  libcurl  first  queries
       the  host  to see which authentication methods it supports and then picks the best one you
       allow it to use. For some methods, this induces  an  extra  network  round-trip.  Set  the
       actual   name   and   password   with   the   CURLOPT_USERPWD(3)   option   or   with  the
       CURLOPT_USERNAME(3) and the CURLOPT_PASSWORD(3) options.

       For authentication with a proxy, see CURLOPT_PROXYAUTH(3).

       CURLAUTH_BASIC
              HTTP Basic authentication. This is the default choice, and the only method that  is
              in  wide-spread use and supported virtually everywhere. This sends the username and
              password over the network in plain text, easily captured by others.

       CURLAUTH_DIGEST
              HTTP Digest authentication. Digest authentication is defined in RFC 2617 and  is  a
              more  secure  way  to  do  authentication  over  public  networks  than the regular
              old-fashioned Basic method.

       CURLAUTH_DIGEST_IE
              HTTP Digest authentication with an IE flavor. Digest authentication is  defined  in
              RFC  2617  and  is a more secure way to do authentication over public networks than
              the regular old-fashioned Basic method. The IE flavor is simply that libcurl uses a
              special  "quirk"  that  IE  is  known  to  have used before version 7 and that some
              servers require the client to use.

       CURLAUTH_BEARER
              HTTP Bearer token authentication, used primarily in OAuth 2.0 protocol.

              You can set the Bearer token to use with CURLOPT_XOAUTH2_BEARER(3).

       CURLAUTH_NEGOTIATE
              HTTP Negotiate (SPNEGO) authentication. Negotiate authentication is defined in  RFC
              4559 and is the most secure way to perform authentication over HTTP.

              You  need  to  build libcurl with a suitable GSS-API library or SSPI on Windows for
              this to work.

       CURLAUTH_NTLM
              HTTP NTLM authentication. A proprietary protocol invented and used by Microsoft. It
              uses  a  challenge-response  and  hash  concept  similar  to Digest, to prevent the
              password from being eavesdropped.

              You need to build libcurl with either OpenSSL or GnuTLS support for this option  to
              work, or build libcurl on Windows with SSPI support.

       CURLAUTH_NTLM_WB
              Support for this is removed since libcurl 8.8.0.

              NTLM delegating to winbind helper. Authentication is performed by a separate binary
              application that is executed when needed. The name of the application is  specified
              at compile time but is typically /usr/bin/ntlm_auth.

              Note  that  libcurl forks when necessary to run the winbind application and kill it
              when complete, calling waitpid() to await its exit when done.  On  POSIX  operating
              systems,  killing  the  process causes a SIGCHLD signal to be raised (regardless of
              whether CURLOPT_NOSIGNAL(3) is set), which must be  handled  intelligently  by  the
              application. In particular, the application must not unconditionally call wait() in
              its SIGCHLD signal handler to  avoid  being  subject  to  a  race  condition.  This
              behavior is subject to change in future versions of libcurl.

       CURLAUTH_ANY
              This  is  a convenience macro that sets all bits and thus makes libcurl pick any it
              finds suitable. libcurl automatically selects the one it finds most secure.

       CURLAUTH_ANYSAFE
              This is a convenience macro that sets all bits except Basic and thus makes  libcurl
              pick  any  it  finds  suitable. libcurl automatically selects the one it finds most
              secure.

       CURLAUTH_ONLY
              This is a meta symbol. OR this value together with a single specific auth value  to
              force  libcurl  to  probe  for  unrestricted auth and if not, only that single auth
              algorithm is acceptable.

       CURLAUTH_AWS_SIGV4
              provides AWS V4 signature authentication on HTTPS header see CURLOPT_AWS_SIGV4(3).

DEFAULT

       CURLAUTH_BASIC

PROTOCOLS

       This functionality affects http only

EXAMPLE

       int main(void)
       {
         CURL *curl = curl_easy_init();
         if(curl) {
           CURLcode ret;
           curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/");
           /* allow whatever auth the server speaks */
           curl_easy_setopt(curl, CURLOPT_HTTPAUTH, (long)CURLAUTH_ANY);
           curl_easy_setopt(curl, CURLOPT_USERPWD, "james:bond");
           ret = curl_easy_perform(curl);
         }
       }

HISTORY

       CURLAUTH_DIGEST_IE was added in 7.19.3

       CURLAUTH_ONLY was added in 7.21.3

       CURLAUTH_NTLM_WB was added in 7.22.0

       CURLAUTH_BEARER was added in 7.61.0

       CURLAUTH_AWS_SIGV4 was added in 7.74.0

AVAILABILITY

       Added in curl 7.10.6

RETURN VALUE

       Returns  CURLE_OK  if  the  option  is  supported,   CURLE_UNKNOWN_OPTION   if   not,   or
       CURLE_NOT_BUILT_IN if the bitmask specified no supported authentication methods.

SEE ALSO

       CURLOPT_PASSWORD(3), CURLOPT_PROXYAUTH(3), CURLOPT_USERNAME(3)