CURLOPT_CAINFO(3)          curl_easy_setopt options          CURLOPT_CAINFO(3)

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 null-terminated string naming a file holding one or
       more certificates to verify the peer with.

       If _SSL_VERIFYPEER&section=3">CURLOPT_SSL_VERIFYPEER(3) is zero and you avoid verifying the
       server's certificate, _CAINFO&section=3">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 _CAINFO&section=3">CURLOPT_CAINFO(3) and
       _CAPATH&section=3">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_CAINFO_BLOB(3), CURLOPT_CAPATH(3),  CURLOPT_SSL_VERIFYPEER(3),
       CURLOPT_SSL_VERIFYHOST(3),

libcurl 7.77.0                   July 13, 2020               CURLOPT_CAINFO(3)