<?php

/**
 * LDAP Password Driver
 *
 * Driver for passwords stored in LDAP
 * This driver use the PEAR Net_LDAP2 class (http://pear.php.net/package/Net_LDAP2).
 *
 * @version 1.1 (2010-04-07)
 * @author Edouard MOREAU <edouard.moreau@ensma.fr>
 *
 * function hashPassword based on code from the phpLDAPadmin development team (http://phpldapadmin.sourceforge.net/).
 * function randomSalt based on code from the phpLDAPadmin development team (http://phpldapadmin.sourceforge.net/).
 *
 */

function password_save($curpass, $passwd)
{
    $rcmail = rcmail::get_instance();
    require_once ('Net/LDAP2.php');

    // Building user DN
    if ($userDN = $rcmail->config->get('password_ldap_userDN_mask')) {
        $userDN = substitute_vars($userDN);
    } else {
        $userDN = search_userdn($rcmail);
    }

    if (empty($userDN)) {
        return PASSWORD_CONNECT_ERROR;
    }

    // Connection Method
    switch($rcmail->config->get('password_ldap_method')) {
        case 'admin':
            $binddn = $rcmail->config->get('password_ldap_adminDN');
            $bindpw = $rcmail->config->get('password_ldap_adminPW');
            break;
        case 'user':
        default:
            $binddn = $userDN;
            $bindpw = $curpass;
            break;
    }

    // Configuration array
    $ldapConfig = array (
        'binddn'    => $binddn,
        'bindpw'    => $bindpw,
        'basedn'    => $rcmail->config->get('password_ldap_basedn'),
        'host'      => $rcmail->config->get('password_ldap_host'),
        'port'      => $rcmail->config->get('password_ldap_port'),
        'starttls'  => $rcmail->config->get('password_ldap_starttls'),
        'version'   => $rcmail->config->get('password_ldap_version'),
    );

    // Connecting using the configuration array
    $ldap = Net_LDAP2::connect($ldapConfig);

    // Checking for connection error
    if (PEAR::isError($ldap)) {
        return PASSWORD_CONNECT_ERROR;
    }

    $crypted_pass = hashPassword($passwd, $rcmail->config->get('password_ldap_encodage'));
    $force        = $rcmail->config->get('password_ldap_force_replace');
    $pwattr       = $rcmail->config->get('password_ldap_pwattr');
    $lchattr      = $rcmail->config->get('password_ldap_lchattr');
    $smbpwattr    = $rcmail->config->get('password_ldap_samba_pwattr');
    $smblchattr   = $rcmail->config->get('password_ldap_samba_lchattr');
    $samba        = $rcmail->config->get('password_ldap_samba');

    // Support password_ldap_samba option for backward compat.
    if ($samba && !$smbpwattr) {
        $smbpwattr  = 'sambaNTPassword';
        $smblchattr = 'sambaPwdLastSet';
    }

    // Crypt new password
    if (!$crypted_pass) {
        return PASSWORD_CRYPT_ERROR;
    }

    // Crypt new samba password
    if ($smbpwattr && !($samba_pass = hashPassword($passwd, 'samba'))) {
	    return PASSWORD_CRYPT_ERROR;
    }

    // Writing new crypted password to LDAP
    $userEntry = $ldap->getEntry($userDN);
    if (Net_LDAP2::isError($userEntry)) {
        return PASSWORD_CONNECT_ERROR;
    }

    if (!$userEntry->replace(array($pwattr => $crypted_pass), $force)) {
        return PASSWORD_CONNECT_ERROR;
    }

    // Updating PasswordLastChange Attribute if desired
    if ($lchattr) {
       $current_day = (int)(time() / 86400);
       if (!$userEntry->replace(array($lchattr => $current_day), $force)) {
           return PASSWORD_CONNECT_ERROR;
       }
    }

    // Update Samba password and last change fields
    if ($smbpwattr) {
        $userEntry->replace(array($smbpwattr => $samba_pass), $force);
    }
    // Update Samba password last change field
    if ($smblchattr) {
        $userEntry->replace(array($smblchattr => time()), $force);
    }

    if (Net_LDAP2::isError($userEntry->update())) {
        return PASSWORD_CONNECT_ERROR;
    }

    // All done, no error
    return PASSWORD_SUCCESS;
}

/**
 * Bind with searchDN and searchPW and search for the user's DN.
 * Use search_base and search_filter defined in config file.
 * Return the found DN.
 */
function search_userdn($rcmail)
{
    $ldapConfig = array (
        'binddn'    => $rcmail->config->get('password_ldap_searchDN'),
        'bindpw'    => $rcmail->config->get('password_ldap_searchPW'),
        'basedn'    => $rcmail->config->get('password_ldap_basedn'),
        'host'      => $rcmail->config->get('password_ldap_host'),
        'port'      => $rcmail->config->get('password_ldap_port'),
        'starttls'  => $rcmail->config->get('password_ldap_starttls'),
        'version'   => $rcmail->config->get('password_ldap_version'),
    );

    $ldap = Net_LDAP2::connect($ldapConfig);

    if (PEAR::isError($ldap)) {
        return '';
    }

    $base = $rcmail->config->get('password_ldap_search_base');
    $filter = substitute_vars($rcmail->config->get('password_ldap_search_filter'));
    $options = array (
            'scope' => 'sub',
            'attributes' => array(),
    );

    $result = $ldap->search($base, $filter, $options);
    $ldap->done();
    if (PEAR::isError($result) || ($result->count() != 1)) {
        return '';
    }

    return $result->current()->dn();
}

/**
 * Substitute %login, %name, %domain, %dc in $str.
 * See plugin config for details.
 */
function substitute_vars($str)
{
    $rcmail = rcmail::get_instance();
    $domain = $rcmail->user->get_username('domain');
    $dc     = 'dc='.strtr($domain, array('.' => ',dc=')); // hierarchal domain string

    $str = str_replace(array(
            '%login',
            '%name',
            '%domain',
            '%dc',
        ), array(
            $_SESSION['username'],
            $rcmail->user->get_username('local'),
            $domain,
            $dc,
        ), $str
    );

    return $str;
}


/**
 * Code originaly from the phpLDAPadmin development team
 * http://phpldapadmin.sourceforge.net/
 *
 * Hashes a password and returns the hash based on the specified enc_type.
 *
 * @param string $passwordClear The password to hash in clear text.
 * @param string $encodageType Standard LDAP encryption type which must be one of
 *        crypt, ext_des, md5crypt, blowfish, md5, sha, smd5, ssha, or clear.
 * @return string The hashed password.
 *
 */

function hashPassword( $passwordClear, $encodageType )
{
    $encodageType = strtolower( $encodageType );
    switch( $encodageType ) {
        case 'crypt': 
            $cryptedPassword = '{CRYPT}' . crypt($passwordClear,randomSalt(2)); 
            break;

        case 'ext_des':
            // extended des crypt. see OpenBSD crypt man page.
            if ( ! defined( 'CRYPT_EXT_DES' ) || CRYPT_EXT_DES == 0 ) {
                // Your system crypt library does not support extended DES encryption.
                return FALSE;
            }
            $cryptedPassword = '{CRYPT}' . crypt( $passwordClear, '_' . randomSalt(8) );
            break;

        case 'md5crypt':
            if( ! defined( 'CRYPT_MD5' ) || CRYPT_MD5 == 0 ) {
                // Your system crypt library does not support md5crypt encryption.
                return FALSE;
            }
            $cryptedPassword = '{CRYPT}' . crypt( $passwordClear , '$1$' . randomSalt(9) );
            break;

        case 'blowfish':
            if( ! defined( 'CRYPT_BLOWFISH' ) || CRYPT_BLOWFISH == 0 ) {
                // Your system crypt library does not support blowfish encryption.
                return FALSE;
            }
            // hardcoded to second blowfish version and set number of rounds
            $cryptedPassword = '{CRYPT}' . crypt( $passwordClear , '$2a$12$' . randomSalt(13) );
            break;

        case 'md5':
            $cryptedPassword = '{MD5}' . base64_encode( pack( 'H*' , md5( $passwordClear) ) );
            break;

        case 'sha':
            if( function_exists('sha1') ) {
                // use php 4.3.0+ sha1 function, if it is available.
                $cryptedPassword = '{SHA}' . base64_encode( pack( 'H*' , sha1( $passwordClear) ) );
            } elseif( function_exists( 'mhash' ) ) {
                $cryptedPassword = '{SHA}' . base64_encode( mhash( MHASH_SHA1, $passwordClear) );
            } else {
                return FALSE; //Your PHP install does not have the mhash() function. Cannot do SHA hashes.
            }
            break;

        case 'ssha':
            if( function_exists( 'mhash' ) && function_exists( 'mhash_keygen_s2k' ) ) {
                mt_srand( (double) microtime() * 1000000 );
                $salt = mhash_keygen_s2k( MHASH_SHA1, $passwordClear, substr( pack( 'h*', md5( mt_rand() ) ), 0, 8 ), 4 );
                $cryptedPassword = '{SSHA}'.base64_encode( mhash( MHASH_SHA1, $passwordClear.$salt ).$salt );
            } else {
                return FALSE; //Your PHP install does not have the mhash() function. Cannot do SHA hashes.
            }
            break;

        case 'smd5':
            if( function_exists( 'mhash' ) && function_exists( 'mhash_keygen_s2k' ) ) {
                mt_srand( (double) microtime() * 1000000 );
                $salt = mhash_keygen_s2k( MHASH_MD5, $passwordClear, substr( pack( 'h*', md5( mt_rand() ) ), 0, 8 ), 4 );
                $cryptedPassword = '{SMD5}'.base64_encode( mhash( MHASH_MD5, $passwordClear.$salt ).$salt );
            } else {
                return FALSE; //Your PHP install does not have the mhash() function. Cannot do SHA hashes.
            }
            break;

        case 'samba':
            if (function_exists('hash')) {
                $cryptedPassword = hash('md4', rcube_charset_convert($passwordClear, RCMAIL_CHARSET, 'UTF-16LE'));
                $cryptedPassword = strtoupper($cryptedPassword);
            } else {
				/* Your PHP install does not have the hash() function */
				return false;
            }
            break;

        case 'clear':
        default:
            $cryptedPassword = $passwordClear;
    }

    return $cryptedPassword;
}

/**
 * Code originaly from the phpLDAPadmin development team
 * http://phpldapadmin.sourceforge.net/
 *
 * Used to generate a random salt for crypt-style passwords. Salt strings are used
 * to make pre-built hash cracking dictionaries difficult to use as the hash algorithm uses
 * not only the user's password but also a randomly generated string. The string is
 * stored as the first N characters of the hash for reference of hashing algorithms later.
 *
 * --- added 20021125 by bayu irawan <bayuir@divnet.telkom.co.id> ---
 * --- ammended 20030625 by S C Rigler <srigler@houston.rr.com> ---
 *
 * @param int $length The length of the salt string to generate.
 * @return string The generated salt string.
 */
function randomSalt( $length )
{
    $possible = '0123456789'.
        'abcdefghijklmnopqrstuvwxyz'.
        'ABCDEFGHIJKLMNOPQRSTUVWXYZ'.
        './';
    $str = '';
//    mt_srand((double)microtime() * 1000000);

    while (strlen($str) < $length)
        $str .= substr($possible, (rand() % strlen($possible)), 1);

    return $str;
}