PHP ModulesPHP Modules

LDAP and MySQL

External FunctionsExternal Functions

• In addition to the usual programming functions (arrays, date and time, typing, mathematical, etc), PHP supports a large number of functions linking it to other software (although many of these require special installation):• MySQL. MS SQL, Oracle 8• Shockwave Flash• PDF• IMAP, POP3, NNTP• XML• Many others…

• In particular, we'll look at the MySQL and LDAP function sets

Review: PHP 5 ArchitectureReview: PHP 5 Architecture

• Recall that PHP is modular…

image from http://www.zend.com/zend/art/intro.php

Examples of FTP FunctionsExamples of FTP Functions

ftp_connect — Opens up an FTP connectionftp_login — Logs in an FTP connectionftp_pwd — Returns the current directory nameftp_cdup — Changes to the parent directoryftp_chdir — Changes directories on a FTP serverftp_mkdir — Creates a directoryftp_rmdir — Removes a directoryftp_nlist — Returns a list of files in the given directory.ftp_get — Downloads a file from the FTP server.ftp_fget — Downloads a file from the FTP server and saves to an open file.ftp_put — Uploads a file to the FTP server.ftp_fput — Uploads from an open file to the FTP server.ftp_size — Returns the size of the given file.ftp_mdtm — Returns the last modified time of the given file.ftp_rename — Renames a file on the ftp server.ftp_delete — Deletes a file on the ftp server.ftp_quit — Closes an FTP connection

LDAPLDAP

• Lightweight Directory Access Protocol

• Like many "light" services, it's gained weight over time--LDAP is just like XML in this regard

• Used to store user data on systems (eg. Active Directory, Open Directory)

• Very commonly used for email addressbooks

• Also can be used for authentication services

LDAP TermsLDAP Terms

• A directory is a collection of entries

• Each entry contains a set of attributes

• Attributes have a name, and contain a value

• A schema governs the form of attributes, much like a DTD or XML Schema governs an XML document

Distinguished NamesDistinguished Names

• Each directory has a root name, the distinguished name

• These days that is usually parallel to the IP domain name or the server's IP name, eg:dc=cs,dc=unc,dc=edu(dc stands for domain component--the older system used geographical components)

• Entries in the tree also have a distinguished name, but that's relative (RDN), eg:cn=hays,ou=affiliates,dc=cs,dc=unc,dc=edu

• This domain based structure allows multiple servers to interact in a hierarchy, much like DNS

Data? Data?Data? Data?

• ldap/abhi_ldap.php• This will show you a dump of my data from ldap.unc.edu (this isn't the only thing up there, but it shows you the kinds of things that are there)

• Same basic data, shown a different way:ldap/person_super.php

LDAP StructureLDAP Structure

• LDAP uses a tree structure• Leaves can be asymmetrical--that is to say, not all leaves have to be populated, and leaves can contain various numbers of subleaves

• This in contrast to the standard table structures--really tho, LDAP sits on top of a DB (usually Berkeley DB) and itself acts as middleware layer

• LDAP has a text file format for import/export called ldif (this stuff is all based on the old X500 stuff, so it predates XML)

LDAP TreesLDAP Trees

image from http://www.twistedmatrix.com/users/tv/ldap-intro/ldap-intro.html

An AsideAn Aside

• X.500 is the old school directory system developed by the ITU

• This was never adopted in a widespread manner, just to complicated

• Developed by telco as a universal directory

• There are implementation similarities to• ANS.1 and SNMP• SGML and XML• ATM

• The lesson: Prototype early and often and plan on throwing the first one away

Import and ExportImport and Export

• LDAP uses a standard text file format for import and export (YAS!)

• This is called LDIF, and you'll see it pretty often in conjunction with supporting email clients

LDIF formatsLDIF formatsdn: cn=Barbara Jensen, ou=Product Development, dc=airius, dc=comobjectclass: topobjectclass: personobjectclass: organizationalPersoncn: Barbara Jensencn: Barbara J Jensencn: Babs Jensensn: Jensenuid: bjensentelephonenumber: +1 408 555 1212description: A big sailing fan.

dn: cn=Bjorn Jensen, ou=Accounting, dc=airius, dc=comobjectclass: topobjectclass: personobjectclass: organizationalPersoncn: Bjorn Jensensn: Jensentelephonenumber: +1 408 555 1212

from http://www.twistedmatrix.com/users/tv/ldap-intro/ldap-intro.html

AdministrationAdministration

• LDAP has a collection of command line tools for unixes, and a host of browsers for all platforms

• There's also a project, phpldapadmin, that is handy for doing ldap administration (and yes, virginia, one could do an ldap and phpldapadmin installation as a project)

• There's an analogous product, phpmysqladmin, for MySQL

PHP and LDAPPHP and LDAP

• Four basic phases• Open a connection to the server:ldap_connect()

• Bind to the server (authenticate)ldap_bind()

• Do your ldap thing• Close the connectionldap_close()

02_super_ldap.php02_super_ldap.php

• The basic connection….

$ldap_server = "ldap.unc.edu:389";$ldap_server = "ldap.unc.edu:389";

……

// Connect to ldap server// Connect to ldap server$ldapconn = ldap_connect($ldap_server)$ldapconn = ldap_connect($ldap_server) or die("Could not connect to LDAP server.");or die("Could not connect to LDAP server.");echo 'ldapconn = ' . $ldapconn;echo 'ldapconn = ' . $ldapconn;echo "<br />";echo "<br />";

02_super_ldap.php02_super_ldap.php

• Binding to ldap// Test to see that we got a connection// Test to see that we got a connectionif ($ldapconn) {if ($ldapconn) { // If the connection requires a password, use this// If the connection requires a password, use this //$ldapbind = ldap_bind($ldapconn, $ldaprdn, //$ldapbind = ldap_bind($ldapconn, $ldaprdn, $ldappass);$ldappass); // If the connection is anonymous, use this// If the connection is anonymous, use this $ldapbind = ldap_bind($ldapconn);$ldapbind = ldap_bind($ldapconn); echo 'ldapbind = ' . $ldapbind . '<br/ >';echo 'ldapbind = ' . $ldapbind . '<br/ >'; // verify binding// verify binding if ($ldapbind) {if ($ldapbind) { echo "LDAP bind successful...";echo "LDAP bind successful..."; } else {} else { echo "LDAP bind failed...";echo "LDAP bind failed..."; }} }}

02_super_ldap.php02_super_ldap.php

• A simple search--$info is an array of entries

$dn = "dc=unc,dc=edu";$dn = "dc=unc,dc=edu";// $justthese is a array of what items // $justthese is a array of what items // to get in the ldap search// to get in the ldap search//$justthese = array("*");//$justthese = array("*");$justthese = array( "sn", "givenname", "uid", "mail");$justthese = array( "sn", "givenname", "uid", "mail");// Filters// Filters// Set the filter you wish to user here by uncommenting the line// Set the filter you wish to user here by uncommenting the line$filter = "(uid=$uid)";$filter = "(uid=$uid)";……echo $filter . ' is the filter <br/>';echo $filter . ' is the filter <br/>';// Set a handle for the ldap search // Set a handle for the ldap search $sr=ldap_search($ldapconn, $dn, $filter, $justthese);$sr=ldap_search($ldapconn, $dn, $filter, $justthese);// Pull the ldap entries found in the search into $info// Pull the ldap entries found in the search into $info$info = ldap_get_entries($ldapconn, $sr);$info = ldap_get_entries($ldapconn, $sr);

02_super_ldap.php02_super_ldap.php

• LDAP searches return multidimensional arrays, so we'll start with print_r()function print_results($info) {function print_results($info) {

// Use a while loop to print the results// Use a while loop to print the results // Each "hit" is an array of arrays of arrays....// Each "hit" is an array of arrays of arrays.... print "<p>" . $info["count"] . " entries returned</p>";print "<p>" . $info["count"] . " entries returned</p>"; $x=0;$x=0; while ($info[$x] != "") {while ($info[$x] != "") { echo "Here is \$info[$x]:<br />";echo "Here is \$info[$x]:<br />"; echo '<pre>';echo '<pre>'; print_r($info[$x]);print_r($info[$x]); echo '</pre>';echo '</pre>'; echo '<br />';echo '<br />'; $x++;$x++; }} }}

02_super_ldap.php through 06_super_ldap.php

02_super_ldap.php through 06_super_ldap.php

• This is ok, but the arrays are complicated and print_r() is ugly

• So what I want is to be able to control the output--I have to traverse the arrays, find the elements I need, and extract those

• To do this, I'll put loops in loops

• I also want a form to control what I'm submitting--a user won't modify the source

03_super_ldap.php03_super_ldap.php

• Added a new var, $search_elements

$ldap_server = "ldap.unc.edu:389";$ldap_server = "ldap.unc.edu:389";// Set the Distinguish Name (which defines the base of the ldap tree)// Set the Distinguish Name (which defines the base of the ldap tree)$dn = "dc=unc,dc=edu";$dn = "dc=unc,dc=edu";// $justthese is a array of what items to get in the ldap search// $justthese is a array of what items to get in the ldap search$justthese = array( "sn", "givenname", "uid", "telephonenumber", "mail");$justthese = array( "sn", "givenname", "uid", "telephonenumber", "mail");// Set the items to build in the radio buttons// Set the items to build in the radio buttons$search_elements = array("sn", "mail", "pid", "telephonenumber", "uid");$search_elements = array("sn", "mail", "pid", "telephonenumber", "uid");

03_super_ldap.php03_super_ldap.php

• Added a new var, $search_elements, this is used in a loop to write out a series of radio buttons

foreach ($search_elements as $radio_button) { echo "<input type=\"radio\" value=\"$radio_button\" name=\"search_field\" /> $radio_button"; }

03_super_ldap.php03_super_ldap.php

• And a function..function print_results($info) { print "<p>" . $info["count"] . " entries returned</p>"; $x=0; while ($info[$x]) { echo "Here is \$info[$x]:<br />"; echo '<pre>'; print_r($info[$x]); echo '</pre>'; echo '<br />'; $x++; } }

03_super_ldap.php03_super_ldap.php

• The search and data return

$sr=ldap_search($ldapconn, $dn, $filter, $justthese); $info = ldap_get_entries($ldapconn, $sr); print_results($info); ldap_close($ldapconn);

04_super_ldap.php04_super_ldap.php

• The print function dices into the $info arrayfunction print_results($info, $justthese) {function print_results($info, $justthese) {

print "<p>" . $info["count"] . " entries returned</p>";print "<p>" . $info["count"] . " entries returned</p>"; $x=0;$x=0; $y=0;$y=0; while ($info[$x] != "") {while ($info[$x] != "") { foreach ($justthese as $item) {foreach ($justthese as $item) { echo "<hr />";echo "<hr />"; echo '<pre>';echo '<pre>'; print_r($info[$x][$item]);print_r($info[$x][$item]); echo '</pre>';echo '</pre>'; $y++; }$y++; } $x++; }$x++; } }}

05_super_ldap.php05_super_ldap.php

• Chucked the print function $x=0;$x=0; while ($info[$x] != "") {while ($info[$x] != "") { echo "<p>";echo "<p>"; foreach ($justthese as $item) {foreach ($justthese as $item) { $y=0;$y=0; while ($info[$x][$item][$y] != "") {while ($info[$x][$item][$y] != "") { print_r($info[$x][$item][$y]);print_r($info[$x][$item][$y]); echo '<br />';echo '<br />'; $y++; }$y++; } }} echo "</p><hr />";echo "</p><hr />"; $x++;$x++; }}

06_super_ldap.php06_super_ldap.php

• A more complicated loop

ldap/abhi_ldap.phpldap/abhi_ldap.php

• A very tight loop$info = ldap_get_entries($ldapconnect, $sr);$info = ldap_get_entries($ldapconnect, $sr);echo $info["count"]." entries returned<br>";echo $info["count"]." entries returned<br>";// $i = entries// $i = entries// $ii = attributes for entry// $ii = attributes for entry// $iii = values per attribute// $iii = values per attributefor ($i = 0; $i<$info["count"]; $i++) {for ($i = 0; $i<$info["count"]; $i++) { for ($ii=0; $ii<$info[$i]["count"]; $ii++){for ($ii=0; $ii<$info[$i]["count"]; $ii++){ $data = $info[$i][$ii];$data = $info[$i][$ii]; for ($iii=0; $iii<$info[$i][$data]["count"]; $iii++) {for ($iii=0; $iii<$info[$i][$data]["count"]; $iii++) { echo $data.":&nbsp;&nbsp;".$info[$i][$data][$iii]."<br>";echo $data.":&nbsp;&nbsp;".$info[$i][$data][$iii]."<br>"; }} }}}}

Other UsesOther Uses

• ldap/listcs_super.php• Takes a list of pids from a text file and pulls sn and displaynames, could pull any other data….

$pid_list_raw = file('./pids_list.txt');$pid_list_raw = file('./pids_list.txt');$pid_list = array_unique($pid_list_raw);$pid_list = array_unique($pid_list_raw);$x=0;$x=0;while ($pid_list[$x] != '') while ($pid_list[$x] != '') {{ // using ldap bind// using ldap bind $ldaprdn = 'pid=700554021,dc=unc,dc=edu'; // ldap rdn or dn$ldaprdn = 'pid=700554021,dc=unc,dc=edu'; // ldap rdn or dn // connect to ldap server// connect to ldap server $ldapconn = ldap_connect("ldap.unc.edu:389")$ldapconn = ldap_connect("ldap.unc.edu:389") or die("Could not connect to LDAP server.");or die("Could not connect to LDAP server."); if ($ldapconn) if ($ldapconn) {{ $ldapbind = ldap_bind($ldapconn);$ldapbind = ldap_bind($ldapconn); // verify binding// verify binding if ($ldapbind) if ($ldapbind) {{ //echo "LDAP bind successful...<br/>";//echo "LDAP bind successful...<br/>"; }} else else {{ echo "LDAP bind failed...";echo "LDAP bind failed..."; }} }}

$pid_list[$x] = trim($pid_list[$x]);$pid_list[$x] = trim($pid_list[$x]);$filter = "(pid=$pid_list[$x])";$filter = "(pid=$pid_list[$x])";$dn = "dc=unc,dc=edu";$dn = "dc=unc,dc=edu";//echo '<p>Hi!' . $filter . ' is the filter </p>';//echo '<p>Hi!' . $filter . ' is the filter </p>';$justthese = array("*");$justthese = array("*");$result = ldap_search($ldapconn, $dn, $filter);$result = ldap_search($ldapconn, $dn, $filter);$sr=ldap_search($ldapconn, $dn, $filter, $justthese);$sr=ldap_search($ldapconn, $dn, $filter, $justthese);$info = ldap_get_entries($ldapconn, $sr);$info = ldap_get_entries($ldapconn, $sr);

if ($info[0]["sn"][0])if ($info[0]["sn"][0]) {{ echo $info[0]["sn"][0] . "," . $info[0]["pid"][0] echo $info[0]["sn"][0] . "," . $info[0]["pid"][0] . ', ' . $info[0]["displayname"][0];. ', ' . $info[0]["displayname"][0]; echo '<br />';echo '<br />'; }} $x++;$x++; }}

Local Advantages to LDAPLocal Advantages to LDAP

• The campus directory is maintained in ldap, so you can get a lot of data from it

• All of the data you can get is public data--if a user has told ITS they do not want their phone number published, it's not there

• That means you don't have to worry about violating privacy, and you're not responsible for the data….

• You can use this to get a user's home dir, public email address, etc.

MySQLMySQL

Keep in mind, I'm not a sql programmer….

What it isWhat it is

• A multithreaded multi user database system

• It has it's own syntax, consistent with SQL

• Developed as an answer to heavy weight commercial dbs such as Oracle and Sybase

• Dual licensed by MySQL AB, which makes the source available under GPL, but also licenses closed versions

• Recently there's been a controversy since the distribution of the source has been slightly restricted

Why use it?Why use it?

• It's free• It's fast, and suits most purposes nicely

• It's relatively easy to understand (oracle and sybase have steeper learning curves)

• If you grow into something that needs additional support, you can buy it later (much as is the case with PHP/Zend)

Everything in a tableEverything in a table

• MySQL stores user information, access controls, passwords, all of it's data, in a database (named mysql), so you need to guard that pretty carefully

• You can allow access to it directly over the network, but consider the need carefully

• I recommend that you only allow access via the local host, and use php for user access--you can always ssh to the server if you need direct access

• If you want to run php code on another server, then only allow that server to connect--but know that all other users on that server can try to connect…

AdministrationAdministration

• Via the command line, use mysql and mysqladmin• mysql is use to create and access databases and tables

• mysqladmin is used to manage the service

• For more info, see dev.mysql.com/doc/refman/5.1/en/index.html

• There's also a nice package, phpmyadmin, you can use to manage databases--installing this and using is could be a project….

Sample CommandsSample Commands

• These are the commands I used to create the table we'll use in the lab

• Commands end with a semi-colon

DROP TABLE IF EXISTS employees;CREATE TABLE employees ( id tinyint(4) NOT NULL AUTO_INCREMENT, first varchar(20), last varchar(20), address varchar(255), city varchar(40), position varchar(50), PRIMARY KEY (id), UNIQUE id (id));

INSERT INTO employees VALUES (1,'Tory','LeMar','128 Here St', 'Cityname','Marketing Manager');

INSERT INTO employees VALUES (2,'Brad','Johnson', '1/34 Nowhere Blvd', 'Snowston','Doorman');

INSERT INTO employees VALUES (3,'Bob','Smith', '128 Here St','Cityname','Marketing Manager');

INSERT INTO employees VALUES (4,'John','Roberts', '45 There St','Townville','Telephonist');

Examples of MySQL FunctionsExamples of MySQL Functions

mysql_change_user — Change logged in user of the active connection mysql_connect — Open a connection to a MySQL Servermysql_create_db — Create a MySQL databasemysql_db_query — Send a MySQL querymysql_drop_db — Drop (delete) a MySQL databasemysql_fetch_field — Get column information from a result and return as an object mysql_fetch_lengths — Get the length of each output in a result mysql_field_table — Get name of the table the specified field is in mysql_field_type — Get the type of the specified field in a result mysql_list_dbs — List databases available on a MySQL server mysql_list_fields — List MySQL result fieldsmysql_list_tables — List tables in a MySQL databasemysql_num_fields — Get number of fields in resultEtc….

Opening a connectionOpening a connection

Notice that the password here is clear in the php source…..

// create a resource handle for the database connection$db = mysql_connect("purple.ils.unc.edu:3306", "hays",

"password");mysql_select_db(widgetco,$db);

// Create a resource variable with the results from // a mysql_query()--this is not a normal variable, but// rather a pointer to the resource's data.$result = mysql_query("SELECT * FROM employees",$db);

Also, do you understand the concept of the handle here?

Using printfUsing printf

// Use printf to get the results to the browser// The %s stands for a string variable, the value from

the first// item after the first command goes into the first

variable, etc.// The result we're pulling is from the zeroth row of

$result// so it's the first line in the tableprintf("First Name: %s<br>\n",

mysql_result($result,0,"first"));printf("Last Name: %s<br>\n",

mysql_result($result,0,"last"));printf("Address: %s<br>\n",

mysql_result($result,0,"address"));printf("City: %s<br>\n", mysql_result($result,0,"city"));printf("Position: %s<br>\n",

mysql_result($result,0,"position"));

Submitting DataSubmitting Data

$id = $_GET["id"];

if ($id) { if ($_POST["submit"]) { $sql = "UPDATE employees SET

first='$first',last='$last',address='$address',

city='$city',position='$position' WHERE id=$id";

// Note that we set data by passing a command to the database

// with a mysql_query() $result = mysql_query($sql); echo "Thank you! Information updated.\n";

A more selective queryA more selective query

// In this query, we're only looking for one line, the one

// with the match id value $querystring = "SELECT * FROM employees WHERE id=" .

$_GET["id"]; $result = mysql_query($querystring,$db); $myrow = mysql_fetch_array($result);

printf("First name: %s\n<br>", $myrow["first"]); printf("Last name: %s\n<br>", $myrow["last"]); printf("Address: %s\n<br>", $myrow["address"]); printf("City: %s\n<br>", $myrow["city"]); printf("Position: %s\n<br>", $myrow["position"]);

Note also that this version uses mysql_fetch_array(), a single query pulls the entire row into a 1d array in php

Some simple examplesSome simple examples

• table_query.php• table_query2.php• table_query3.php• table_query4.php• table.php• table01.php• table02.php

Material from the LabMaterial from the Lab

Optional LabOptional Lab

• I've set up a db on purple.ils.unc.edu, you can play with it if you like with this lab:/labs/php_and_mysql.html

More InfoMore Info

• Wikipedia on LDAP• DevShed on PHP and MySQL