CURLOPT_SSLKEY - private keyfile for TLS and SSL client cert
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_SSLKEY, char *keyfile);
Pass a pointer to a null-terminated string as parameter. The string should be
the file name of your private key. The default format is "PEM" and
can be changed with CURLOPT_SSLKEYTYPE(3).
(Windows, iOS and Mac OS X) This option is ignored by Secure
Transport and Schannel SSL backends because they expect the private key to
be already present in the keychain or PKCS#12 file containing the
The application does not have to keep the string around after
setting this option.
All TLS based protocols: HTTPS, FTPS, IMAPS, POP3S, SMTPS etc.
CURL *curl = curl_easy_init();
curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/");
curl_easy_setopt(curl, CURLOPT_SSLCERT, "client.pem");
curl_easy_setopt(curl, CURLOPT_SSLKEY, "key.pem");
curl_easy_setopt(curl, CURLOPT_KEYPASSWD, "s3cret");
ret = curl_easy_perform(curl);
Returns CURLE_OK if TLS is supported, CURLE_UNKNOWN_OPTION if not, or
CURLE_OUT_OF_MEMORY if there was insufficient heap space.