<HTML ><HEAD ><TITLE >Secure the Interface</TITLE ><META NAME="GENERATOR" CONTENT="Modular DocBook HTML Stylesheet Version 1.7"><LINK REL="HOME" TITLE="Secure Programming for Linux and Unix HOWTO" HREF="index.html"><LINK REL="UP" TITLE="Structure Program Internals and Approach" HREF="internals.html"><LINK REL="PREVIOUS" TITLE="Follow Good Software Engineering Principles for Secure Programs" HREF="follow-good-principles.html"><LINK REL="NEXT" TITLE="Separate Data and Control" HREF="data-vs-control.html"></HEAD ><BODY CLASS="SECT1" BGCOLOR="#FFFFFF" TEXT="#000000" LINK="#0000FF" VLINK="#840084" ALINK="#0000FF" ><DIV CLASS="NAVHEADER" ><TABLE SUMMARY="Header navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TH COLSPAN="3" ALIGN="center" >Secure Programming for Linux and Unix HOWTO</TH ></TR ><TR ><TD WIDTH="10%" ALIGN="left" VALIGN="bottom" ><A HREF="follow-good-principles.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" >Chapter 7. Structure Program Internals and Approach</TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="data-vs-control.html" ACCESSKEY="N" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><DIV CLASS="SECT1" ><H1 CLASS="SECT1" ><A NAME="SECURE-INTERFACE" ></A >7.2. Secure the Interface</H1 ><P >Interfaces should be minimal (simple as possible), narrow (provide only the functions needed), and non-bypassable. Trust should be minimized. Consider limiting the data that the user can see.</P ></DIV ><DIV CLASS="NAVFOOTER" ><HR ALIGN="LEFT" WIDTH="100%"><TABLE SUMMARY="Footer navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" ><A HREF="follow-good-principles.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="index.html" ACCESSKEY="H" >Home</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" ><A HREF="data-vs-control.html" ACCESSKEY="N" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >Follow Good Software Engineering Principles for Secure Programs</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="internals.html" ACCESSKEY="U" >Up</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >Separate Data and Control</TD ></TR ></TABLE ></DIV ></BODY ></HTML >