1. CS1001 Lecture 9

2. Overview Security Security HTML HTML

3. Goals Examine network security issues Examine network security issues Learn Basic HTML Learn Basic HTML Become familiar with Columbia’s web server Become familiar with Columbia’s web server

4. Assignments Brookshear: Ch 8.2, 8.3 (Read) Brookshear: Ch 8.2, 8.3 (Read) Read HTML Primers Read HTML Primers –http://www.columbia.edu/acis/webdev/ http://www.columbia.edu/acis/webdev/ –http://www.davesite.com/webstation/html/ http://www.davesite.com/webstation/html/ –http://www.w3.org/MarkUp/ http://www.w3.org/MarkUp/ Read linked documents on these slides (slides will be posted in courseworks) Read linked documents on these slides (slides will be posted in courseworks)

5. Web Servers Web servers are publicly accessible (connected to the Internet) servers that return requested files via the HTTP protocol Web servers are publicly accessible (connected to the Internet) servers that return requested files via the HTTP protocol A web browser can connects to a web server to retrieve this document A web browser can connects to a web server to retrieve this document –Note, however, that web browsers may also load HTML documents from any place on your local computer

6. Security Web Applications are programs that anyone can access at any time Web Applications are programs that anyone can access at any time Malformed data can be sent in an attempt to break the behavior of the web application Malformed data can be sent in an attempt to break the behavior of the web application

7. Web Applications Web servers that return dynamically generated web pages in response to user input are called Web Applications Web servers that return dynamically generated web pages in response to user input are called Web Applications Programming languages used for this are ASP, PHP, JSP, Perl-CGI and others Programming languages used for this are ASP, PHP, JSP, Perl-CGI and others

8. Display Versus Meaning HTML is designed to structure information HTML is designed to structure information It is up to each individual browser as to how the structure should be rendered on screen It is up to each individual browser as to how the structure should be rendered on screen In modern years, Cascading Style Sheets enhance HTML to provide strict control over display preference In modern years, Cascading Style Sheets enhance HTML to provide strict control over display preference

9. HTML Reference Stick with items above tables in the following reference (but feel free to experiment with tables) Stick with items above tables in the following reference (but feel free to experiment with tables) http://hotwired.lycos.com/webmonkey/reference/html_cheatsheet/ http://hotwired.lycos.com/webmonkey/reference/html_cheatsheet/ http://hotwired.lycos.com/webmonkey/reference/html_cheatsheet/