openssl/demos/bio/accept.cnf

# Example configuration file
# Port to listen on
Port = 4433
# Disable TLS v1.2 for test.
# Protocol = ALL, -TLSv1.2
# Only support 3 curves
Curves = P-521:P-384:P-256
# Automatic curve selection
ECDHParameters = Automatic
# Restricted signature algorithms
SignatureAlgorithms = RSA+SHA512:ECDSA+SHA512 
Certificate=server.pem
PrivateKey=server.pem
ChainCAFile=root.pem
VerifyCAFile=root.pem

# Request certificate
VerifyMode=Request
ClientCAFile=root.pem