ssl.py 文件源码

def get_server_certificate(addr, ssl_version=PROTOCOL_SSLv23, ca_certs=None):
    """Retrieve the certificate from the server at the specified address,
    and return it as a PEM-encoded string.
    If 'ca_certs' is specified, validate the server cert against it.
    If 'ssl_version' is specified, use it in the connection attempt."""

    host, port = addr
    if ca_certs is not None:
        cert_reqs = CERT_REQUIRED
    else:
        cert_reqs = CERT_NONE
    context = _create_stdlib_context(ssl_version,
                                     cert_reqs=cert_reqs,
                                     cafile=ca_certs)
    with closing(create_connection(addr)) as sock:
        with closing(context.wrap_socket(sock)) as sslsock:
            dercert = sslsock.getpeercert(True)
    return DER_cert_to_PEM_cert(dercert)