Table Of Content

Includes securing Mac OS X Internet Security forY our Macintosh A Guide for the Rest of Us An essential guide to keeping your Mac safe at home, on the road, or in the office. Includes safe surfing, AirPort wireless security, virus safeguards, and Mac OS X precautions. ALAN B. OPPENHEIMER CHARLES H. WHITAKER AND Internet Security for Your Macintosh A Guide for the Rest of Us Alan B. Oppenheimer and Charles H. Whitaker Peachpit Press • Berkeley, California 0 Internet Security for Your Macintosh: A Guide for the Rest of Us Alan B. Oppenheimer and Charles H. Whitaker Peachpit Press 1249 Eighth Street Berkeley, CA 94710 (510) 524-2178 (800) 283-9444 (510) 524-2221 (fax) Find us on the World Wide Web at: www.peachpit.com Peachpit Press is a division of Pearson Education Copyright 02001 Alan B. Oppenheimer and Charles H. Whitaker Editor: Clifford Colby Copy Editor: Kathy Simpson Production Coordinator: Connie Jeung-Mills Compositor: Owen Wolfson Cover Design: TMA Ted Mader + Associates Cover Compositor: Mimi Heft Cover Illustration: John Grimes Indexer: James Minkin Notice of Rights All rights reserved. No part of this book may be reproduced or transmitted in any form by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of the publisher. For information on getting permission for reprints and excerpts, contact Gary-Paul Prince at Peachpit Press. Notice of Liability The information in this book is distributed on an "As is" basis, without warranty. While every pre caution has been taken in the preparation of the book, neither the author nor Peachpit Press shall have any liability to any person or entity with respect to any loss or damage caused or alleged to be caused directly or indirectly by the instructions contained in this book or by the computer software and hardware products described in it. Trademarks Throughout this book, trademarked names are used. Rather than put a trademark symbol in each occur rence of a trademarked name, we state we are using the names only in an editorial fashion and to the benefit of the trademark owner with no intention of infringement of the trademark. ISBN 0-201-74969-6 9 8 7 6 5 4 3 2 Printed and bound in the United States of America. To: Macintosh users everywhere From: Alan and Charles Subject: Keep thinking different! Thank You Writing this book took place in two stages. The first stage lasted either seventeen or six years, depending on what you count. For the seventeen part, we'd like to thank all the people at Apple who helped to create and bring the Macintosh to market, helped to create a network (AppleTalk) for it, and helped to bring another one (the Internet) to it. Without you, this book would have been impossible on many levels. For the six part, we'd like to thank the entire Open Door family, who provided the experience and insights we needed to write this book-along with a whole lot of fun. The second writing stage was much shorter and more concentrated. It often felt like we were compressing those seventeen years into about six months. For that stage, we'd like to thank all the people at Peachpit Press and in particular our editor, Cliff Colby. Without you, all the knowledge we've accumulated during the first stage would still be unwritten and unavailable. Finally, we· d like to thank our wives, families, and friends. This book is your accomplishment as well as ours. Alan B. Oppenheimer Charles H. Whitaker June 2001 Table of Contents Chapter 1 Getting Started 1 About This Book ................................ 3 About the Authors . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 4 PART ONE: GENERAL SECURITY PRINCIPLES 5 Chapter 2 What, Me Worry? 7 More People on the Net More Often . . . . . . . . . . . . . . .. 8 More People Doing More Important Things ............ 9 More and More Attacks . . . . . . . . . . . . . . . . . . . . . . . . . 1 0 Why Me? .................................... 12 It Gets Worse . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Broadband Connections Are Especially Vulnerable ...... 15 But I Use a Macl .............................. 17 What, Me Worry Too Much? ..................... 19 Chapter 3 Physical Security 21 Things that Can Go Wrong ....................... 22 Physical Security First ........................... 23 Things Will Go Wrong Anyway .................... 24 Backup options .................................. 25 Good backup procedures ........................... 28 v INTERNET SECURITY FOR YOUR MACINTOSH : Chapter 4 Managing Passwords 29 : More and More Passwords . . . . . . . . . . . ............ 30 Web-site passwords ............................... 31 Passwords for other services ........................ 31 : Choosing Good Passwords ....................... 32 · Making a password hard to guess .................... 33 Making a password easy to remember ................. 35 : Keeping Your Passwords Secret .................... 36 : Managing Your Passwords ....................... 38 Using the keychain ............................... 38 Other password-management techniques ............... 40 Dealing with forgotten passwords .................... 45 : Passwords in the Future ......................... 46 Digital certificates ................................ 46 Other password options . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 7 : Chapter 5 Safe Surfing 49 : Safe Web Browsing ............................. 50 Secure and insecure Web pages ...................... 50 Think before you type ............................. 53 Other Web-security issues .......................... 55 · Safe E-mail ................................... 58 Sending your e-mail password ....................... 58 Sending e-mail .................................. 61 Sending e-mail securely ............................ 62 Receiving attachments ............................. 64 Other issues with receiving e-mail .................... 69 : Safety with Other Internet Applications .............. 71 : Chapter 6 Internet Basics 73 : Infrastructure ................................. 74 · Protocols .................................... 76 : IP Addresses and Host Names ..................... 79 Static versus dynamic IP addresses .................... 79 Public versus private IP addresses ..................... 80 Subnet masks ................................... 81 vi TABLE OF CONTENTS Routers ........................................ 82 Host names and domain names ...................... 83 The Domain Name System .......................... 83 Port Numbers ................................. 84 The TCP/IP Control Panel ........................ 86 Configuring your Mac for cable-modem access with a dynamic IP address .......................... 86 Configuring your Mac for cable-modem access with a static IP address ............................ 88 Configuring your Mac for dial-up connection ............ 89 TCP/IP configurations ............................. 90 Mac OSX ...................................... 90 PART TWO: SECURING INTERNET SERVICES 93 Chapter 7 Principles of Securing Internet Services 95 Using Versus Providing Internet Services ............. 96 Levels of Security .............................. 97 AppleTalk and TCP/IP ........................... 98 Users & Groups ............................... 99 Chapter 8 Securing Common Mac OS Internet Services 10 1 File Sharing ................................. 102 Risk ......................................... 105 Security measures ............................... 1 06 Web Sharing ................................ 109 Risk ......................................... 110 Security measures ............................... 112 Program Linking .............................. 115 Risk ......................................... 116 Security measures ............................... 117 vii INTERNET SECURITY FOR YOUR MACINTOSH : Chapter 9 Securing Other Mac OS Internet Services 119 : Remote Access . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120 Risk ......................................... 121 Security measures ............................... 122 : Apple Network Assistant . . . . . . . . . . . . . . . . . . . . . . . . 123 Risk ......................................... 124 Security measures ............................... 125 : SNMP ..................................... 126 Risk ......................................... 128 Securityme~ures ............................... 128 : Apple File Security ............................ 130 : Chapter 10 Securing Third-Party Internet Services 133 · Timbuktu ................................... 134 Risk ......................................... 136 Security measures ............................... 137 : Retrospect . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140 Risk ......................................... 141 Security measures ............................... 142 : FileMaker Pro ................................ 144 Risk ......................................... 144 Security measures ............................... 145 : ShareWay IP ................................. 148 · Risk ......................................... 151 Security measures ............................... 152 : Other Applications ............................ 153 Risk ......................................... 154 Security me~ures ............................... 155 viii TABLE OF CONTENTS PART THREE: ENHANCING OVERALL SECURITY 157 Chapter 11 Viruses 159 What Viruses Are ............................. 160 How they work ................................. 161 Where they come from ........................... 162 Types of viruses ................................. 163 What Viruses Can Do .......................... 165 Unintentional damage ............................ 166 Intentional damage .............................. 167 What You Can Do About Them ................... 169 Going beyond safe surfing ......................... 169 Getting an antivirus application ..................... 171 Installing an antivirus application .................... 173 Using an antivirus application ...................... 175 Chapter 12 Personal Firewalls 179 Firewall Basics ................................ 180 Firewall types .................................. 180 How firewalls work .............................. 181 Stateful firewalls ................................ 184 Features .................................... 185 Protocols supported .............................. 186 Firewall feedback ............................... 187 Other kinds of attacks ............................ 189 Multihoming support ............................. 190 Outgoing-packet protection ....................... 191 Ease-of-use features ............................. 192 Configuring a Personal Firewall ................... 192 Allowing access to specific TCP/IP services ............. 193 Allowing access to all TCP II P services ................. 196 Protecting UDP services ........................... 196 Denying access to ICMP .......................... 198 Logging ...................................... 199 Setting up notification ............................ 199 Using stealth mode .............................. 200 ix