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ldap_compare

PHP function Edit on GitHub ✎

(PHP 4 >= 4.0.2, PHP 5, PHP 7, PHP 8)

Compare value of attribute found in entry specified with DN

Description

ldap_compare(LDAP\Connection $ldap, string $dn, string $attribute, string $value, array|null $controls = null): bool|int

Compare value of attribute with value of same attribute in an LDAP directory entry.

Parameters

ldap: Ldap
dn: The distinguished name of an LDAP entity.
attribute: The attribute name.
value: The compared value.
controls: Array of LDAP Controls to send with the request.

Return Values

Returns true if value matches otherwise returns false. Returns -1 on error.

Warning

Both true and -1 are truthy, so a plain truth test such as if (ldap_compare(...)) treats an error as a match. The result must be compared strictly against true.

Changelog

Version	Description
7.3.0	Support for `controls` added

Examples

The following example demonstrates how to check whether or not given password matches the one defined in DN specified entry.

Complete example of password check

php

<?php

$ds=ldap_connect("localhost");  // assuming the LDAP server is on this host

if ($ds) {

    // bind
    if (ldap_bind($ds)) {

        // prepare data
        $dn = "cn=Matti Meikku, ou=My Unit, o=My Company, c=FI";
        $value = "secretpassword";
        $attr = "password";

        // compare value
        $r=ldap_compare($ds, $dn, $attr, $value);

        if ($r === -1) {
            echo "Error: " . ldap_error($ds);
        } elseif ($r === true) {
            echo "Password correct.";
        } elseif ($r === false) {
            echo "Wrong guess! Password incorrect.";
        }

    } else {
        echo "Unable to bind to LDAP server.";
    }

    ldap_close($ds);

} else {
    echo "Unable to connect to LDAP server.";
}
?>

Notes

Warning

ldap_compare() can NOT be used to compare BINARY values!

Source: reference/ldap/functions/ldap-compare.xml · from the official PHP manual (php/doc-en)