Add certification authority for performing verification.
void add_certificate_authority( const const_buffer & ca, asio::error_code & ec);
This function is used to add one trusted certification authority from a memory buffer.
The buffer containing the certification authority certificate. The certificate must use the PEM format.
Set to indicate what error occurred, if any.
Calls SSL_CTX_get_cert_store
and X509_STORE_add_cert
.