Boost C++ Libraries

...one of the most highly regarded and expertly designed C++ library projects in the world. — Herb Sutter and Andrei Alexandrescu, C++ Coding Standards

Use a certificate chain from a file.

boost::system::error_code use_certificate_chain_file(
    const std::string & filename,
    boost::system::error_code & ec);

This function is used to load a certificate chain into the context from a file.

filename: The name of the file containing the certificate. The file must use the PEM format.
ec: Set to indicate what error occurred, if any.