NAME

       CURLOPT_CAINFO - path to Certificate Authority (CA) bundle

SYNOPSIS

       #include <curl/curl.h>

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

DESCRIPTION

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

       If CURLOPT_SSL_VERIFYPEER(3) is zero and you avoid verifying the server's certificate,  CURLOPT_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.  Starting with curl-7.55.0, if both CURLOPT_CAINFO(3) and
       CURLOPT_CAPATH(3) are unset, NSS-linked libcurl tries  to  load  libnssckbi.so,  which  contains  a  more
       comprehensive  set  of  trust  information than supported by nss-pem, because libnssckbi.so also includes
       information about distrusted certificates.

       (iOS and macOS) When curl uses Secure Transport this option is supported. If the option is not set,  then
       curl will use the certificates in the system and user Keychain to verify the peer.

       (Schannel)  This  option  is  supported  for Schannel in Windows 7 or later but we recommend not using it
       until Windows 8 since it works better starting then.  If the option is not set, then curl  will  use  the
       certificates in the Windows' store of root certificates (the default for Schannel).

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

DEFAULT

       Built-in system specific. When curl is built with Secure Transport or Schannel, this option is not set by
       default.

PROTOCOLS

       All TLS based protocols: HTTPS, FTPS, IMAPS, POP3S, SMTPS etc.

EXAMPLE

       CURL *curl = curl_easy_init();
       if(curl) {
         curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/");
         curl_easy_setopt(curl, CURLOPT_CAINFO, "/etc/certs/cabundle.pem");
         ret = curl_easy_perform(curl);
         curl_easy_cleanup(curl);
       }

AVAILABILITY

       For the SSL engines that don't support certificate files the CURLOPT_CAINFO option is  ignored.  Schannel
       support added in libcurl 7.60.

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_CAPATH(3), CURLOPT_SSL_VERIFYPEER(3), CURLOPT_SSL_VERIFYHOST(3),