CS122B: Projects in Databases and Web Applications Winter 2017 Notes 04: Domain Registration and reCaptcha Professor Chen Li Department of Computer Science CS122B

Motivation Register a domain name for people to remember More flexibility to change the IP address(es) If we change the IP address, as long as the domain name is mapped to the new address, we are good Important for marketing and sales CS122B

Steps Go to a domain registrar site such as GoDaddy Search for a good, available domain name Purchase it! CS122B

A good domain name is important! People tend to remember meaningful names, even if they are long: CarsInIrvine.com Try to avoid weird acronyms CS122B

Domain Parking “Registration of an internet domain name without that domain being associated with any services” For sale For ads CS122B

Mapping domain to IP Example: cs122b.com I purchased it from Godaddy.com Modify its zone file to map it to my AWS instance For now on I can access cs122b.com instead of ec2-52-36-XXX-XX.us-west-2.compute.amazonaws.com  CS122B

reCaptcha: preventing internet bots Web sites have valuable information Example: ticketmaster.com “Bad people” write programs/bots to send bad requests (e.g., registration, buying tickets) CS122B

First version: captcha Use Captcha to correct OCR errors CS122B

2nd version: recaptcha CS122B

reCaptcha example: TomcatFormReCaptcha.war index.html 3. g-recaptcha-response Client Browser Tomcat Server 2. g-recaptcha-response 4. g-recaptcha-response Secret Key 1. Site Key Google reCaptcha Server CS122B