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* Made all examples and text work with register_globals = off (closes bug #18328)

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* Minor textual changes, and added links to other manual sections
* A little whitespace fixing


git-svn-id: https://svn.php.net/repository/phpdoc/en/trunk@88596 c90b9560-bf6c-de11-be94-00142212c4b1
This commit is contained in:
Philip Olson 2002-07-13 21:37:03 +00:00
parent d5bd17527d
commit 6cdf0cb2f1
1 changed files with 57 additions and 31 deletions
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88
features/http-auth.xml
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@ -1,5 +1,5 @@
<?xml version="1.0" encoding="iso-8859-1"?>
<!-- $Revision: 1.26 $ -->
<!-- $Revision: 1.27 $ -->
<chapter id="features.http-auth">
<title>HTTP authentication with PHP</title>
@ -10,25 +10,41 @@
<function>header</function> function to send an "Authentication Required"
message to the client browser causing it to pop up a Username/Password
input window. Once the user has filled in a username and a password,
the URL containing the PHP script will be called again with the variables,
$PHP_AUTH_USER, $PHP_AUTH_PW and $PHP_AUTH_TYPE set to the user
name, password and authentication type respectively. Only "Basic"
authentication is supported at this point. See the <function>header</function>
function for more information.</simpara>
the URL containing the PHP script will be called again with the
<link linkend="reserved.variables">predefined variables</link>
<varname>PHP_AUTH_USER</varname>, <varname>PHP_AUTH_PW</varname>,
and <varname>PHP_AUTH_TYPE</varname> set to the user name, password and
authentication type respectively. These predefined variables are found
in the <link linkend="reserved.variables.server">$_SERVER</link> and
<varname>$HTTP_SERVER_VARS</varname> arrays. Only "Basic" authentication
is supported. See the <function>header</function> function for more
information.
</simpara>
<note>
<title>PHP Version Note</title>
<para>
<link linkend="language.variables.superglobals">Autoglobals</link>,
such as <link linkend="reserved.variables.server">$_SERVER</link>, became
available in PHP version <ulink url="&url.php.release4.1.0;">4.1.0</ulink>.
<varname>$HTTP_SERVER_VARS</varname> has been available since PHP 3.
</para>
</note>
<para>
An example script fragment which would force client authentication
on a page would be the following:
on a page is as follows:
</para>
<para>
<example>
<title>HTTP Authentication example</title>
<programlisting role="php">
<![CDATA[
<?php
if (!isset($_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\n";
header('WWW-Authenticate: Basic realm="My Realm"');
header('HTTP/1.0 401 Unauthorized');
echo 'Text to send if user hits Cancel button\n';
exit;
} else {
echo "<p>Hello {$_SERVER['PHP_AUTH_USER']}.</p>";
@ -37,38 +53,45 @@
?>
]]>
</programlisting>
</example></para>
</example>
</para>
<note>
<title>Note</title>
<title>Compatibility Note</title>
<para>
Please be careful when coding the HTTP header lines. In order to guarantee maximum
compatibility with all clients, the keyword "Basic" should be written with an
uppercase "B", the realm string must be enclosed in double (not single) quotes,
and exactly one space should precede the "401" code in the "HTTP/1.0 401" header line.
and exactly one space should precede the <emphasis>401</emphasis> code in the
<emphasis>HTTP/1.0 401</emphasis> header line.
</para>
</note>
<para>
Instead of simply printing out the $PHP_AUTH_USER and
$PHP_AUTH_PW, you would probably want to check the username and
password for validity. Perhaps by sending a query to a database,
or by looking up the user in a dbm file.</para>
Instead of simply printing out <varname>PHP_AUTH_USER</varname>
and <varname>PHP_AUTH_PW</varname>, as done in the above example,
you may want to check the username and password for validity.
Perhaps by sending a query to a database, or by looking up the
user in a dbm file.
</para>
<para>
Watch out for buggy Internet Explorer browsers out there. They
seem very picky about the order of the headers. Sending the
<emphasis>WWW-Authenticate</emphasis> header before the
<literal>HTTP/1.0 401</literal> header seems to do the trick
for now.</para>
for now.
</para>
<simpara>
In order to prevent someone from writing a script which reveals
the password for a page that was authenticated through a
traditional external mechanism, the PHP_AUTH variables will not be
set if external authentication is enabled for that particular
page. In this case, the $REMOTE_USER variable can be used to
identify the externally-authenticated user.</simpara>
page. In this case, <varname>REMOTE_USER</varname> can be used
to identify the externally-authenticated user. So,
<varname>$_SERVER['REMOTE_USER']</varname>.
</simpara>
<note>
<title>Configuration Note</title>
@ -84,27 +107,29 @@
<simpara>
Note, however, that the above does not prevent someone who
controls a non-authenticated URL from stealing passwords from
authenticated URLs on the same server.</simpara>
authenticated URLs on the same server.
</simpara>
<simpara>
Both Netscape Navigator and Internet Explorer will clear the local browser
window's authentication cache for the realm upon receiving a
server response of 401. This can effectively "log out" a user,
forcing them to re-enter their username and password. Some people
use this to "time out" logins, or provide a "log-out" button.</simpara>
<simpara></simpara>
use this to "time out" logins, or provide a "log-out" button.
</simpara>
<para>
<example>
<title>HTTP Authentication example forcing a new name/password</title>
<programlisting role="php">
<![CDATA[
<?php
function authenticate() {
header( "WWW-Authenticate: Basic realm=\"Test Authentication System\"");
header( "HTTP/1.0 401 Unauthorized");
header('WWW-Authenticate: Basic realm="Test Authentication System"');
header('HTTP/1.0 401 Unauthorized');
echo "You must enter a valid login ID and password to access this resource\n";
exit;
}
if (!isset($_SERVER['PHP_AUTH_USER']) || ($SeenBefore == 1 && $OldAuth == $_SERVER['PHP_AUTH_USER']))) {
if (!isset($_SERVER['PHP_AUTH_USER']) || ($_POST['SeenBefore'] == 1 && $_POST['OldAuth'] == $_SERVER['PHP_AUTH_USER'])) {
authenticate();
}
else {
@ -118,8 +143,9 @@
}
?>
]]>
</programlisting>
</example>
</programlisting>
</example>
</para>
<simpara>
This behavior is not required by the HTTP Basic authentication
standard, so you should never depend on this. Testing with Lynx
@ -136,7 +162,7 @@
<note>
<para>
If <link linkend="ini.safe-mode">safe mode</link> is enabled the
If <link linkend="ini.safe-mode">safe mode</link> is enabled, the
uid of the script is added to the <literal>realm</literal> part of
the <literal>WWW-Authenticate</literal> header.
</para>