11.3.1. Comparing Cookies with Basic Authentication

There's no such thing as an explicit HTTP error message that means "you needed to send me a proper cookie, so try again!". The "Register Now!" page that the New York Times site returned is not an error in any HTTP sense; as far as the browser is concerned, it asked for something, and got it.

LWP's interface for HTTP cookies and HTTP Basic Authentication is different. To get an LWP::UserAgent browser object to implement cookies, one assigns it an object of class HTTP::Cookies (or a subclass), which represents a little database of cookies that this browser knows about. But there is no corresponding class for groups of username/password pairs, although I informally refer to the set of passwords that a user agent can consult as its "key ring."

11.3.2. Authenticating via LWP

$browser->credentials(
  'servername:portnumber',
  'realm-name',
  'username' => 'password'
);

In most cases, the port number is 80, the default TCP/IP port for HTTP. For example:

my $browser = LWP::UserAgent->new;
$browser->name('ReportsBot/1.01');

$browser->credentials(
  'reports.mybazouki.com:80',
  'web_server_usage_reports',
  'plinky' => 'banjo123'
);

my $response = $browser->get(
  'http://reports.mybazouki.com/this_week/'
);

One can call the credentials method any number of times, to add all the server-port-realm-username-password keys to the browser's key ring, regardless of whether they'll actually be needed. For example, you could read them all in from a datafile at startup:

my $browser = LWP::UserAgent->new( );
if(open(KEYS, "< keyring.dat")) {
  while(<KEYS>) {
    chomp;
    my @info = split "\t", $_, -1;
    $browser->credential(@info) if @info == 4;
  };
  close(KEYS);
}

11.3.3. Security