Network Security: Lab#3 Transport-Level Security Tools J. H. Wang May 12, 2011

Objectives To learn to use transport-level security tools –SSL/TLS clients/servers To learn to access secure Web services –HTTPS To learn to use secure shell –SSH

Packages Used in this Lab OpenSSL: an open source implementation of SSL and TLS protocols –(again!) PuTTY: an implementation of SSH –PuTTY: for telnet and ssh –PSFTP: for secure FTP

OpenSSL Homepage: Current version: 1.0.0d (open source) –Source: Unix/Linux: openssl-1.0.0d.tar.gz –Binary: Win32 OpenSSL : –Win32 OpenSSL v1.0.0d –Visual C Redistributables Steps –Install (skipped) –OpenSSL command-line tool

Experiment Scenario Running a generic SSL/TLS server Connecting to a SSL/TLS server Connecting to a secure remote Web server Remote login a host Transferring files to/from a remote host

OpenSSL Command-Line Tools OpenSSL command-line tool –s_server: a generic SSL/TLS server cd \OpenSSL-Win32\bin openssl s_server -cert PEM\server.pem Or openssl s_server -cert PEM\server.pem - accept 443 -www –For HTML output –s_client: a generic SSL/TLS client openssl s_client Default: localhost:443

Another Example Another example: –s_server: other options cd \OpenSSL-Win32\bin openssl s_server -cert PEM\server.pem - accept www –For HTML output –Use a Web browser to connect

Yet Another Example Still another example: –s_server: other options cd \OpenSSL-Win32\bin openssl s_server -cert PEM\server.pem - accept 443 -WWW –For simulating a Web server –Put a file under the directory \OpenSSL-Win32\bin cp index.html \OpenSSL-Win32\bin\ –Use a Web browser to connect and get the page

HTTPS HTTP over TLS –Implemented on most browsers Example services –CSIE Webmail: –Gmail: –Facebook: You can also setup a secure Web server –E.g. Apache-SSL, Apache+mod_ssl

Creating a Secure Web Server Apache-SSL: Apache SSL-1.60 –Homepage: –Configuration files, digital certificates Mod_ssl: with Apache –Homepage: –Installation: See Tab [Example]

Secure Shell PuTTY beta 0.60: a free implementation of Telnet and SSH for Windows and Unix – am/putty/download.htmlhttp:// am/putty/download.html –For Windows: (Binaries) putty.exe: Telnet and SSH client psftp.exe: SFTP client –For Unix: (Source) Putty-0.60.tar.gz

Examples on Windows Ex.1: Connecting to a remote host with PuTTY (similar to Telnet) Ex.2: Transferring a file to/from a remote host with PSFTP (similar to FTP)

Connecting to a remote host

Transferring a file to/from a remote host

Examples on UNIX/Linux Ex.1: Connecting to a remote host (similar to Telnet) – ssh -l Ex.: ssh -l You can run commands on a remote host Ex.2: Transferring a file to/from a remote host (similar to FTP) – Ex.: You can upload your homepage to the server

Some Commands in UNIX/Linux Displaying the files – ls Change directory – cd In FTP/sftp: –Displaying the files: ls –Displaying the local files: !dir –Change directory: cd –Change local directory: lcd –Upload files: put –Download files: get –Quit the system: bye

Summary Running a generic SSL/TLS server Connecting to a SSL/TLS server HTTPS Secure shell