openssl API to extract the leaf certificate from a certificate chain available in SSL_CTX

I am using OpenSSL API calls in my C program to establish Mutual-TLS connection to a remote server.

When establishing the connection, the client uses any X509 PEM certificate (i.e.self-signed, CA-issued leaf cert or a chained certificate) provided by the user.

I load the user-provided certificate to my SSL_CTX via call to: SSL_CTX_use_certificate_chain_file (), which can load both single certificate or certificate chain.

My objective is to print the leaf certificate metadata in the prompt something like below:

% my_tls_client -key foo.key -cert foo.crt myserver.com:2566
Attempting to connect to server myserver.com port:2566
Using host certificate as follows:
    serial: aa:bb:cc:dd:ee
    subject: foo...
    valid from: DATE1
    valid untill: DATE2
    WARNING: The provided certificate is about to expire in X days !
    Connected to server successfully!

To do so, first I need to identify and fetch the leaf (host) certificate in X509_STORE available in SSL_CTX.

Is there any OpenSSL API that can get me the leaf certificate from the chain of certificates?

I came across a few approaches like: https://stackoverflow.com/a/58559886/3050164
That suggests using: SSL_CTX_get0_certificate(), But I am unable to find any reference to this method in OpenSSL docs.

Also, another API: X509_STORE_CTX_get_current_cert()
This too does not seem to provide the leaf certificate specifically...

The certificate used is specific to the SSL connection and not to the context (which can be used for different connections). The API you are probably looking for is SSL_get_certificate.