CURLINFO_TLS_SESSION(3) Library Functions Manual CURLINFO_TLS_SESSION(3)

CURLINFO_TLS_SESSION - get TLS session info

#include <curl/curl.h>
CURLcode curl_easy_getinfo(CURL *handle, CURLINFO_TLS_SESSION,
                           struct curl_tlssessioninfo **session);

This option has been superseded by CURLINFO_TLS_SSL_PTR(3) which was added in 7.48.0. The only reason you would use this option instead is if you could be using a version of libcurl earlier than 7.48.0.

This option is exactly the same as CURLINFO_TLS_SSL_PTR(3) except in the case of OpenSSL. If the session backend is CURLSSLBACKEND_OPENSSL the session internals pointer varies depending on the option:

CURLINFO_TLS_SESSION(3) OpenSSL session internals is SSL_CTX *.

CURLINFO_TLS_SSL_PTR(3) OpenSSL session internals is SSL *.

You can obtain an SSL_CTX pointer from an SSL pointer using OpenSSL function SSL_get_SSL_CTX(3). Therefore unless you need compatibility with older versions of libcurl use CURLINFO_TLS_SSL_PTR(3). Refer to that document for more information.

All TLS based protocols: HTTPS, FTPS, IMAPS, POP3S, SMTPS etc.

This option works only with the following TLS backends: GnuTLS and OpenSSL

int main(void)
{
  CURL *curl = curl_easy_init();
  if(curl) {
    CURLcode res;
    struct curl_tlssessioninfo *tls;
    curl_easy_setopt(curl, CURLOPT_URL, "https://example.com");
    res = curl_easy_perform(curl);
    if(res)
      printf("error: %s\n", curl_easy_strerror(res));
    curl_easy_getinfo(curl, CURLINFO_TLS_SESSION, &tls);
    curl_easy_cleanup(curl);
  }
}

Added in 7.34.0. Deprecated since 7.48.0 and supported by OpenSSL and GnuTLS only up until this version was released.

Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not.

CURLINFO_TLS_SSL_PTR(3), curl_easy_getinfo(3), curl_easy_setopt(3)

2024-05-22 libcurl