DOKK / manpages / debian 12 / libcurl4-doc / CURLOPT_PROXY_CAPATH.3.en
CURLOPT_PROXY_CAPATH(3) curl_easy_setopt options CURLOPT_PROXY_CAPATH(3)

CURLOPT_PROXY_CAPATH - directory holding HTTPS 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.

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

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),

January 2, 2023 libcurl 7.88.1