NAME

       CURLOPT_PROXY_CAINFO - path to proxy Certificate Authority (CA) bundle

SYNOPSIS

       #include <curl/curl.h>

       CURLcode curl_easy_setopt(CURL *handle, CURLOPT_PROXY_CAINFO, char *path);

DESCRIPTION

       This option is for connecting to a HTTPS proxy, not a HTTPS server.

       Pass  a  char * to a zero terminated string naming a file holding one or more certificates
       to verify the HTTPS proxy with.

       If  CURLOPT_PROXY_SSL_VERIFYPEER(3)  is  zero  and  you  avoid  verifying   the   server's
       certificate, CURLOPT_PROXY_CAINFO(3) need not even indicate an accessible file.

       This  option is by default set to the system path where libcurl's cacert bundle is assumed
       to be stored, as established at build time.

       If curl is built against the NSS SSL library, the NSS PEM  PKCS#11  module  (libnsspem.so)
       needs to be available for this option to work properly.

       (iOS  and  macOS  only)  If  curl  is  built against Secure Transport, then this option is
       supported for backward compatibility with other SSL engines, but it should not be set.  If
       the option is not set, then curl will use the certificates in the system and user Keychain
       to verify the peer, which is the preferred method  of  verifying  the  peer's  certificate
       chain.

       The application does not have to keep the string around after setting this option.

DEFAULT

       Built-in system specific

PROTOCOLS

       Used with HTTPS proxy

EXAMPLE

       CURL *curl = curl_easy_init();
       if(curl) {
         curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/");
         /* using a HTTPS proxy */
         curl_easy_setopt(curl, CURLOPT_PROXY, "https://localhost:443");
         curl_easy_setopt(curl, CURLOPT_PROXY_CAINFO, "/etc/certs/cabundle.pem");
         ret = curl_easy_perform(curl);
         curl_easy_cleanup(curl);
       }

AVAILABILITY

       Added in 7.52.0

       For  TLS backends that don't support certificate files, the CURLOPT_PROXY_CAINFO(3) option
       is ignored. Refer to https://curl.haxx.se/docs/ssl-compared.html

RETURN VALUE

       Returns  CURLE_OK  if  the  option  is  supported,   CURLE_UNKNOWN_OPTION   if   not,   or
       CURLE_OUT_OF_MEMORY if there was insufficient heap space.

SEE ALSO

       CURLOPT_PROXY_CAPATH(3), CURLOPT_PROXY_SSL_VERIFYPEER(3), CURLOPT_PROXY_SSL_VERIFYHOST(3),
       CURLOPT_CAPATH(3), CURLOPT_SSL_VERIFYPEER(3), CURLOPT_SSL_VERIFYHOST(3),