CURLOPT_CAPATH - Man Page

#include <curl/curl.h>

CURLcode curl_easy_setopt(CURL *handle, CURLOPT_CAPATH, char *capath);

Pass a char pointer to a null-terminated string naming a directory holding multiple CA certificates to verify the peer with. If libcurl is built against OpenSSL, the certificate directory must be prepared using the OpenSSL c_rehash utility. This makes sense only when used in combination with the CURLOPT_SSL_VERIFYPEER(3) option.

The CURLOPT_CAPATH(3) function apparently does not work in Windows due to some limitation in OpenSSL.

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

Using this option multiple times makes the last set string override the previous ones. Set it to NULL to disable its use again.

The default value for this can be figured out with CURLINFO_CAPATH(3).

A path detected at build time.

This functionality affects all TLS based protocols: HTTPS, FTPS, IMAPS, POP3S, SMTPS etc.

This option works only with the following TLS backends: GnuTLS, OpenSSL, mbedTLS and wolfSSL

int main(void)
{
  CURL *curl = curl_easy_init();
  if(curl) {
    CURLcode res;
    curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/");
    curl_easy_setopt(curl, CURLOPT_CAPATH, "/etc/cert-dir");
    res = curl_easy_perform(curl);
    curl_easy_cleanup(curl);
  }
}

Added in curl 7.9.8

CURLE_OK if supported; or an error such as:

CURLE_NOT_BUILT_IN - Not supported by the SSL backend

CURLE_UNKNOWN_OPTION

CURLE_OUT_OF_MEMORY

CURLINFO_CAPATH(3), CURLOPT_CAINFO(3), CURLOPT_DEBUGFUNCTION(3), CURLOPT_STDERR(3)

curl_easy_getinfo(3), curl_easy_setopt(3), CURLINFO_CAPATH(3), CURLOPT_CA_CACHE_TIMEOUT(3), CURLOPT_CAINFO(3), CURLOPT_CAINFO_BLOB(3), CURLOPT_DOH_SSL_VERIFYPEER(3), CURLOPT_PINNEDPUBLICKEY(3), CURLOPT_PROXY_CAINFO(3), CURLOPT_PROXY_CAINFO_BLOB(3), CURLOPT_SSL_VERIFYPEER(3), libcurl-symbols(3), nbdkit-curl-plugin(1).