DOKK / manpages / debian 11 / libcurl4-doc / CURLOPT_PROXY_CAPATH.3.en
CURLOPT_PROXY_CAPATH(3) curl_easy_setopt options CURLOPT_PROXY_CAPATH(3)

CURLOPT_PROXY_CAPATH - specify directory holding proxy CA certificates

#include <curl/curl.h>

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

Pass a char * to a null-terminated string naming a directory holding multiple CA certificates to verify the HTTPS proxy with. If libcurl is built against OpenSSL, the certificate directory must be prepared using the openssl c_rehash utility. This makes sense only when CURLOPT_PROXY_SSL_VERIFYPEER(3) is enabled (which it is by default).

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

NULL

Everything used over an HTTPS proxy

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_CAPATH, "/etc/cert-dir");
ret = curl_easy_perform(curl);
curl_easy_cleanup(curl); }

Added in 7.52.0

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_PROXY_CAINFO(3), CURLOPT_CAINFO(3), CURLOPT_PROXY_SSL_VERIFYHOST(3), CURLOPT_STDERR(3), CURLOPT_DEBUGFUNCTION(3),

November 4, 2020 libcurl 7.74.0