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Chapter 9. Web, Remote Access, and VPN Security. Objectives. Understand Internet security using protocols and services Configure Web browsers for security Configure remote access services for security Configure virtual private network services for security. Internet Security.
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Chapter 9 Web, Remote Access, and VPN Security
Objectives • Understand Internet security using protocols and services • Configure Web browsers for security • Configure remote access services for security • Configure virtual private network services for security Guide to Operating System Security
Internet Security • Protocols and services must be kept secure • To ensure privacy of information • To discourage the spread of malicious software Guide to Operating System Security
Internet Protocols and Services • Hypertext Transfer Protocol (HTTP) • Secure HTTP (S-HTTP) and Hypertext Transfer Protocol Secure (HTTPS) • File Transfer Protocol (FTP) • Network File System (NFS) • Samba and Server Message Block (SMB) Guide to Operating System Security
HTTP • TCP/IP-compatible application protocol-transports information over the Web • Most recent version: HTTP/1.1 • Increases reliability of communications • Enables caching • Can send message responses before full control information from a request is received • Permits multiple communications over a single connection Guide to Operating System Security
S-HTTP and HTTPS • Forms of HTTP used for more secure communications • S-HTTP • Standards-based protocol that enables use of a variety of security measures (including CMS and MOSS) • HTTPS • Essentially proprietary, but more compatible with encryption for IP-level communications • Uses SSL as a subprotocol Guide to Operating System Security
File Transfer Protocol (FTP) • TCP/IP protocol that transfers files in bulk data streams • Uses two TCP ports (20 and 21) • Supports transmission of binary or ASCII formatted files • Commonly used on the Internet • Downloading files can be risky Guide to Operating System Security
File Transfer Protocol (FTP) Guide to Operating System Security
Network File System (NFS) • Designed for UNIX/Linux systems for file sharing • Connection-oriented protocol that runs within TCP • Uses remote procedure calls via TCP port 111 • Sends data in record streams • For security, let only authorized computers use NFS on host computer Guide to Operating System Security
Samba and Server Message Block • Samba • Available for UNIX and Linux computers • Enables exchange of files and printer sharing with Windows-based computers through SMB protocol • Server Message Block • Used by Windows-based systems • Enables sharing files and printers • Employed by Samba Guide to Operating System Security
Using Samba Guide to Operating System Security
Configuring Web Browsers for Security • Applying security measures to popular Web browsers • Internet Explorer • Mozilla • Netscape Navigator Guide to Operating System Security
Configuring Internet Explorer Security • Used with Windows and Mac OS X • Configure version of HTTP, use of HTTPS, FTP, and download access • Configure security by zones • Internet • Local intranet • Trusted sites • Restricted sites Guide to Operating System Security
Internet Explorer Security Settings Guide to Operating System Security
Configuring Internet Explorer Security • Internet Explorer Enhanced Security Configuration (Windows Server 2003) • Applies default security to protect server • Uses security zones and security parameters preconfigured for each zone Guide to Operating System Security
Installing IE Enhanced Security Configuration Guide to Operating System Security
Configuring Mozilla Security • Open-source Web browser • Can run on • Linux (by default with GNOME desktop) • UNIX • Mac OS X • OS/2 • Windows-based systems • Security configuration is combined with privacy configuration options Guide to Operating System Security
Mozilla Security Categories Guide to Operating System Security
Privacy & Security Option in Mozilla Guide to Operating System Security
Configuring Netscape Navigator Security • Nearly identical to Mozilla; GUI offers: • A buddy list • Link to Netscape channels • Different sidebar presentation Guide to Operating System Security
Netscape Navigator in Windows 2000 Server Guide to Operating System Security
Privacy & Security Options in Netscape Guide to Operating System Security
Configuring Remote Access Services for Security • Remote access • Ability to access a workstation or server through a remote connection (eg, dial-up telephone line and modem) • Commonly used by telecommuters Guide to Operating System Security
Microsoft Remote Access Services • Enables off-site workstations to access a server through telecommunications lines, the Internet, or intranets Guide to Operating System Security
Microsoft RAS Guide to Operating System Security
Microsoft RAS - Supported Clients • MS-DOS • Windows 3.1 and 3.11 • Windows NT/95/98 • Windows Millennium • Windows 2000 • Windows Server 2003 and XP Professional Guide to Operating System Security
Microsoft RAS • Supports different types of modems and communications equipment • Compatible with many network transport and remote communications protocols Guide to Operating System Security
Microsoft RAS – Supported Connections (Continued) • Asynchronous modems • Synchronous modems • Null modem communications • Regular dial-up telephone lines • Leased telecommunication lines (eg, T-carrier) Guide to Operating System Security
Microsoft RAS – Supported Connections (Continued) • ISDN lines (and “digital modems”) • X.25 lines • DSL lines • Cable modem lines • Frame relay lines Guide to Operating System Security
Microsoft RAS – Supported Protocols • NetBEUI • TCP/IP • NWLink • PPP • PPTP • L2TP Guide to Operating System Security
Understanding Remote Access Protocols • Transport protocols • TCP/IP • IPX • NetBEUI • Remote access protocols • Serial Line Internet Protocol (SLIP) • CSLIP • Point-to-Point Protocol (PPP) • PPTP • L2TP Guide to Operating System Security
Configuring a RAS Policy • Employ callback security options (No Callback, Set by Caller, Always Callback to) • Install Internet Authentication Service (IAS) • Can be employed with Remote Authentication Dial-In User Service (RADIUS) and RADIUS server • Add participating RAS and VPN servers Guide to Operating System Security
Remote Access Policies Objects in the IAS Tree Guide to Operating System Security
Granting Remote Access Permission to RAS Guide to Operating System Security
Enabling Access for a User’s Account via Remote Access Policy Guide to Operating System Security
Configuring a RAS Policy • Use Remote Access Policies to configure security types • Authentication • Encryption • Dial-in constraints Guide to Operating System Security
RAS Authentication Types (Continued) • Challenge Handshake Authentication Protocol (CHAP) • Extensible Authentication Protocol (EAP) • MS-CHAP v1 (aka CHAP with Microsoft extensions) • MS-CHAP v2 (aka CHAP with Microsoft extensions version 2) Guide to Operating System Security
RAS Authentication Types (Continued) • Password Authentication Protocol (PAP) • Shiva Password Authentication Protocol (SPAP) • Unauthenticated Guide to Operating System Security
RAS Encryption Options Guide to Operating System Security
RAS Dial-in Constraints Options • Idle and session timeouts • Day and time restrictions • Whether access is restricted to a single number • Whether access is restricted based on media used Guide to Operating System Security
Security on a Virtual Private Network • VPN • An intranet designed for restricted access by specific clients based on subnets, IP addresses, user accounts, or a combination • Apply same remote access policies as to RAS servers Guide to Operating System Security
Summary • Protocols and services that enable Internet security • Configuring Web browsers for security • Internet Explorer • Mozilla • Netscape Navigator • How to configure a server’s remote access services to enforce security • Applying security options to a VPN Guide to Operating System Security