CURLOPT_SSLCERTTYPE - Man Page

#include <curl/curl.h>

CURLcode curl_easy_setopt(CURL *handle, CURLOPT_SSLCERTTYPE, char *type);

Pass a pointer to a null-terminated string as parameter. The string should be the format of your certificate.

Supported formats are "PEM" and "DER", except with Secure Transport or Schannel. OpenSSL (versions 0.9.3 and later), Secure Transport (on iOS 5 or later, or macOS 10.7 or later) and Schannel support "P12" for PKCS#12-encoded files.

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

Using this option multiple times makes the last set string override the previous ones. Set it to NULL restores back to internal default.

"PEM"

This functionality affects all TLS based protocols: HTTPS, FTPS, IMAPS, POP3S, SMTPS etc.

This option works only with the following TLS backends: GnuTLS, OpenSSL, Schannel, Secure Transport, mbedTLS and wolfSSL

int main(void)
{
  CURL *curl = curl_easy_init();
  if(curl) {
    CURLcode res;
    curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/");
    curl_easy_setopt(curl, CURLOPT_SSLCERT, "client.pem");
    curl_easy_setopt(curl, CURLOPT_SSLCERTTYPE, "PEM");
    curl_easy_setopt(curl, CURLOPT_SSLKEY, "key.pem");
    curl_easy_setopt(curl, CURLOPT_KEYPASSWD, "s3cret");
    res = curl_easy_perform(curl);
    curl_easy_cleanup(curl);
  }
}

Added in curl 7.9.3

Returns CURLE_OK if TLS is supported, CURLE_UNKNOWN_OPTION if not, or CURLE_OUT_OF_MEMORY if there was insufficient heap space.

CURLOPT_SSLCERT(3), CURLOPT_SSLKEY(3)

curl_easy_setopt(3), CURLOPT_PROXY_SSLCERTTYPE(3), CURLOPT_SSLCERT(3), CURLOPT_SSLCERT_BLOB(3), libcurl-symbols(3).