Re: PHP Username & Password Detection From PSQL Database

Hi again.

After a recommendation, i have changed my approach and i'm now using a html
form to accept the username and password.

Please view the following link:
http://www.cyber.brad.ac.uk/~yamkedoo/Tests/brandnew.html

The username 'yamkedoo' and password 'yasmine' will give Successful Login.
This works for all usernames and passwords in the database.

Though if a different password is used, Access Denied is printed as well as
an error, Warning: Unable to jump to row 0 on PostgreSQL result index 2 in
/home/webpages/yamkedoo/Tests/brandnew.php on line 16, that I am unable to
solve. This applies for all incorrect passwords. Please view my code:

<?php
#Connects to the database
$database = pg_Connect ("host=pgdbs.inf.brad.ac.uk dbname = yamkedoo user =
yamkedoo password = yamkedoo");

if(!$database)
{
echo "Connection Failed<BR>";
}

else
{
#assign formusername from html form to
$auth_user
#assign formpassword from html form to
$auth_pass
$auth_user = trim($formusername);
$auth_pass = trim($formpassword);

$query = "SELECT * FROM PatPerInfo WHERE trim(username) = '$auth_user' AND
trim(password) = '$auth_pass'";
$result = pg_exec($database, $query);
$row = pg_fetch_object($result, $rw);

if($row)
{
print "Successful Login\n";
}

else
{
print "Access Denied\n";
}
}

pg_close($database);

?>

If anyone can spot any mistakes, i will welcome suggestions ;-)

Thanx

>From: Andrew McMillan <andrew(at)catalyst(dot)net(dot)nz>
>To: Yasmine Kedoo <yazkedoo(at)hotmail(dot)com>
>CC: pgsql-php(at)postgresql(dot)org
>Subject: Re: [PHP] PHP Username & Password Detection From PSQL Database
>Date: Wed, 07 Apr 2004 21:35:22 +1200
>
>On Wed, 2004-04-07 at 20:59, Yasmine Kedoo wrote:
> > Hi.
> >
> > I am just beginning to work with PHP & PSQL so forgive me if i make
>simple
> > mistakes. :-)
> >
> > I created my PSQL database via telnet on my university's database
>server. I
> > have no problems retrieving and displaying certain data using PHP, but i
>am
> > unable to recognise a username and password entered via a predefined
> > authentication variable, $PHP_AUTH_USER.
> >
> > The script must recognise the username: 'yamkedoo', and password:
>'yasmine'.
> > In the database, the username & password columns are spelt exactly as:
> > 'username' & 'password'. The database name is 'yamkedoo', and the table
>name
> > is 'PatPerInfo', as can be seen from the following code:
>
>The example in the PHP manual is:
>
><?php
> if (!isset($_SERVER['PHP_AUTH_USER'])) {
> header('WWW-Authenticate: Basic realm="My Realm"');
> header('HTTP/1.0 401 Unauthorized');
> echo 'Text to send if user hits Cancel button';
> exit;
> } else {
> echo "<p>Hello {$_SERVER['PHP_AUTH_USER']}.</p>";
> echo "<p>You entered {$_SERVER['PHP_AUTH_PW']} as your
>password.</p>";
> }
>?>
>
>A couple of notes:
>
>1) You have <?PHP well down your page - you need this before the PHP
>starts (like in the example above). Lowercase is also a lot more normal
>(although probably uppercase still works).
>
>2) The example above shows the syntax for more recent PHP versions, with
>some security features enabled (i.e. use of $_SERVER['PHP_AUTH_USER']
>rather than $PHP_AUTH_USER) whether the older syntax you have used below
>will work will depend on how the installation was configured, to some
>extent, as well as the version you are using.
>
>
> >
> > if(!isset($PHP_AUTH_USER))
> > {
> > Header("WWW-Authenticate: Basic realm=\"Authentication\"");
> > Header( "HTTP/1.0 401 Unauthorized");
> >
> > echo "No Login\n";
> > exit;
> > }
> > else
> > {
> > echo "User: $PHP_AUTH_USER<BR>";
> > echo "Password: $PHP_AUTH_PW<BR>";
> > }
> > <?PHP
> > $database = pg_connect("host=pgdbs.inf.brad.ac.uk dbname=yamkedoo
> > user=yamkedoo password=yamkedoo");
> >
> > if(!$database)
> > {
> > print "Connection to database failed.";
> > }
> >
> > else
> > {
> > $selectquery = "SELECT * FROM PatPerInfo";
> > $result = pg_exec($database, $selectquery);
> >
> > $maxrows = pg_numrows($result);
> > $maxfields = pg_numfields($result);
> >
> > for ($rw = 0; $rw < $maxrows; $rw++)
> > {
>
>Just as a suggestion you might want to consider:
>
>$row = pg_fetch_object($result, $rw);
>if ( trim($_SERVER['PHP_AUTH_USER']) == trim($row->username)
> trim($_SERVER['PHP_AUTH_PW']) == trim($row->password) )
>{
> ...
>
>Actually, though, you can get the database to do it:
>
>$auth_user = pg_escape_string(trim($_SERVER['PHP_AUTH_USER']));
>$auth_pass = pg_escape_string(trim($_SERVER['PHP_AUTH_PW']));
>$selectquery = "SELECT * FROM PatPerInfo
> WHERE trim(username) = '$auth_user'
> AND trim(password) = '$auth_pass'";
>
>$result = pg_exec( ...
>
>
>Doing it this way you can simply see if you got back exactly one row,
>and if you did then that should be the correct user record - no need for
>PHP to inefficiently loop through all of the table looking.
>
>
> > $username = pg_Result($result,$rw,0);
> > $password = pg_Result($result,$rw,1);
> >
>
>Aren't you missing a comparison on the line below?
>
> > if( trim($PHP_AUTH_USER) == trim($username) && (trim($PHP_AUTH_PW))
> > {
> > $auth = 1;
> > }
> > }
> >
> > echo $auth;
> > }
> >
> > if($auth==0)
> > {
> > print "Access Denied<BR>\n";
> > exit;
> > }
> >
> >
> > ?>
> >
> > After the username and password, i get the following error: Parse error:
> > parse error in /home/webpages/yamkedoo/Tests/referrals2.php on line 44.
> >
> > Please view te following link:
> > http://www.cyber.brad.ac.uk/~yamkedoo/Tests/referrals2.php to see what
>is
> > happening.
> > Only once has the authentication window appeared, and has not done so
>since.
> > It only gives the error as seen at the link.
>
>Once you have provided the correct credentials to basic auth, your web
>browser will repeatedly provide them each time until you exit the
>browser or cancel them.
>
>Most sites don't use Basic Authentication like the above - generally
>some form of session is maintained through URL rewriting or cookies
>since that allows a lot more control (and graphical design) fitting the
>login process more smoothly into the web page.
>
>Regards,
> Andrew.
>
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