Need help - Client Authentication

[Jason Qian via openssl-users <openssl-users@xxxxxxxxxxx>]

Hi,

I am working on a TLS server that requires client autiendaction. 

SSL version: OpenSSL 1.1.1n 

I have following calls(Server) :

const SSL_METHOD* method = TLSv1_2_server_method();
SSL_CTX * _ctx = SSL_CTX_new(method);

...

SSL_CTX_use_certificate_file(_ctx, CertificateFile.c_str(), SSL_FILETYPE_PEM);
SSL_CTX_set_default_passwd_cb_userdata(_ctx, (void*)TLS_KEY_PASSWD);
SSL_CTX_use_PrivateKey_file(_ctx, PrivateKeyFile.c_str(), SSL_FILETYPE_PEM);
SSL_CTX_set_verify(_ctx, SSL_VERIFY_PEER | SSL_VERIFY_FAIL_IF_NO_PEER_CERT, NULL);
SSL_CTX_load_verify_locations(_ctx, TLS_CA_FILE, NULL);
SSL_CTX_set_client_CA_list(_ctx, SSL_load_client_CA_file(TLS_CA_FILE));

....

SSL * _ssl = SSL_new(_ctx);

SSL_set_fd(_ssl, conn);

SSL_accept(_ssl);

The server seems to work fine.  My question is  regarding "SSL_CTX_set_default_passwd_cb_userdata".

Do I need to set the password? I tried with/without the call and all seemed to work fine.

Thanks for your help,

Jason