Use an RSA private key from a file.
void use_rsa_private_key_file( const std::string & filename, file_format format);
This function is used to load an RSA private key into the context from a file.
The name of the file containing the RSA private key.
The file format (ASN.1 or PEM).
Thrown on failure.
Calls SSL_CTX_use_RSAPrivateKey_file
.