SilcAuthResult
    silc_message_signed_verify(SilcMessagePayload message,
                               SilcPublicKey remote_public_key,
                               SilcHash hash);

    This routine can be used to verify the digital signature from the
    message indicated by `message'.  The signature is present only if
    the SILC_MESSAGE_FLAG_SIGNED is set in the message flags.  This
    returns SILC_AUTH_OK if the signature verification was successful.