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* Copyright (C) 1998 - 2021, Daniel Stenberg, <daniel@haxx.se>, et al.
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* This software is licensed as described in the file COPYING, which
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CURLOPT_CAPATH - directory holding CA certificates #include <curl/curl.h> CURLcode curl_easy_setopt(CURL *handle, CURLOPT_CAPATH, char *capath); Pass a char * 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. A default path detected at build time. All TLS based protocols: HTTPS, FTPS, IMAPS, POP3S, SMTPS etc.

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

This option is supported by the OpenSSL, GnuTLS and mbedTLS (since 7.56.0) backends. The NSS backend provides the option only for backward compatibility. 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 CURLOPT_CAINFO "(3), " CURLOPT_STDERR "(3), " CURLOPT_DEBUGFUNCTION "(3), "