CURLOPT_PROXY_CAINFO(3)    curl_easy_setopt options    CURLOPT_PROXY_CAINFO(3)

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 an HTTPS proxy, not an HTTPS server.

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

       If _PROXY_SSL_VERIFYPEER&section=3">CURLOPT_PROXY_SSL_VERIFYPEER(3) is zero and you avoid verifying the
       server's certificate, _PROXY_CAINFO&section=3">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 an 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
       _PROXY_CAINFO&section=3">CURLOPT_PROXY_CAINFO(3) option is ignored. Refer to
       https://curl.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_CAINFO_BLOB(3), CURLOPT_PROXY_CAPATH(3),
       CURLOPT_PROXY_SSL_VERIFYPEER(3), CURLOPT_PROXY_SSL_VERIFYHOST(3),
       CURLOPT_CAINFO(3), CURLOPT_CAINFO_BLOB(3),  CURLOPT_CAPATH(3),
       CURLOPT_SSL_VERIFYPEER(3), CURLOPT_SSL_VERIFYHOST(3),

libcurl 7.77.0                   July 13, 2020         CURLOPT_PROXY_CAINFO(3)