PHP MySQL - Stilson.net

www.it-ebooks.infoCHAPTER 14 • AUTHENTICATING YOUR USERSListing 14-4. Authenticating a User Against a Flat File Login Repository// If not authorized, display authentication prompt or 401 errorif (! $authorized) {header('WWW-Authenticate: Basic Realm="Secret Stash"');header('HTTP/1.0 401 Unauthorized');print('You must provide the proper credentials!');exit;}// restricted material goes here...Although the file-based authentication system works well for relatively small, static authenticationlists, this strategy can quickly become inconvenient when you’re handling a large number of users; whenusers are regularly being added, deleted, and modified; or when you need to incorporate anauthentication scheme into a larger information infrastructure such as a preexisting user table. Suchrequirements are better satisfied by implementing a database-based solution. The following sectiondemonstrates just such a solution, using a database to store authentication pairs.Database-Based AuthenticationOf all the various authentication methodologies discussed in this chapter, implementing a databasedrivensolution is the most powerful because it not only enhances administrative convenience andscalability, but also can be integrated into a larger database infrastructure. For purposes of this example,the data store is limited to three fields: a primary key, a username, and a password. These columns areplaced into a table called logins, shown in Listing 14-5.■ Note If you’re unfamiliar with MySQL and are confused by the syntax found in this example, consider reviewingthe material found in Chapter 30.309