CURLOPT_PROXY_SSLKEYTYPE − set type of the proxy private key file
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_PROXY_SSLKEYTYPE, char *type);
This option is for connecting to an HTTPS proxy, not an HTTPS server.
Pass a pointer to a null-terminated string as parameter. The string should be the format of your private key. Supported formats are "PEM", "DER" and "ENG".
The application does not have to keep the string around after setting this option.
Used with HTTPS proxy
CURL *curl =
curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/");
curl_easy_setopt(curl, CURLOPT_PROXY, "https://proxy");
curl_easy_setopt(curl, CURLOPT_PROXY_SSLCERT, "client.pem");
curl_easy_setopt(curl, CURLOPT_PROXY_SSLKEY, "key.pem");
curl_easy_setopt(curl, CURLOPT_PROXY_SSLKEYTYPE, "PEM");
curl_easy_setopt(curl, CURLOPT_PROXY_KEYPASSWD, "s3cret");
ret = curl_easy_perform(curl);
Added in 7.52.0
Returns CURLE_OK if TLS is supported, CURLE_UNKNOWN_OPTION if not, or CURLE_OUT_OF_MEMORY if there was insufficient heap space.
CURLOPT_PROXY_SSLKEY(3), CURLOPT_PROXY_SSLCERT(3), CURLOPT_SSLKEYTYPE(3),