CURLOPT_PROXY_SSLKEY − specify private keyfile for TLS and SSL proxy client cert
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_PROXY_SSLKEY, char *keyfile);
Pass a pointer to a null-terminated string as parameter. The string should be the file name of your private key used for connecting to the HTTPS proxy. The default format is "PEM" and can be changed with CURLOPT_PROXY_SSLKEYTYPE(3).
(iOS and Mac OS X only) This option is ignored if curl was built against Secure Transport. Secure Transport expects the private key to be already present in the keychain or PKCS#12 file containing the certificate.
The application does not have to keep the string around after setting this option.
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_KEYPASSWD, "s3cret");
ret = curl_easy_perform(curl);
Added in 7.52.0
If built TLS enabled.
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_SSLKEYTYPE(3), CURLOPT_PROXY_SSLCERT(3), CURLOPT_SSLKEYTYPE(3), CURLOPT_SSLCERT(3),