<?php

/**
 * Simple LDAP Password Driver
 *
 * Driver for passwords stored in LDAP
 * This driver is based on Edouard's LDAP Password Driver, but does not
 * require PEAR's Net_LDAP2 to be installed
 *
 * @version 2.0
 * @author Wout Decre <wout@canodus.be>
 */

class rcube_ldap_simple_password
{
    function save($curpass, $passwd)
    {
        $rcmail = rcmail::get_instance();

        // Connect
        if (!$ds = ldap_connect($rcmail->config->get('password_ldap_host'), $rcmail->config->get('password_ldap_port'))) {
            ldap_unbind($ds);
            return PASSWORD_CONNECT_ERROR;
        }

        // Set protocol version
        if (!ldap_set_option($ds, LDAP_OPT_PROTOCOL_VERSION, $rcmail->config->get('password_ldap_version'))) {
            ldap_unbind($ds);
            return PASSWORD_CONNECT_ERROR;
        }

        // Start TLS
        if ($rcmail->config->get('password_ldap_starttls')) {
            if (!ldap_start_tls($ds)) {
                ldap_unbind($ds);
                return PASSWORD_CONNECT_ERROR;
            }
        }

        // Build user DN
        if ($user_dn = $rcmail->config->get('password_ldap_userDN_mask')) {
            $user_dn = $this->substitute_vars($user_dn);
        }
        else {
            $user_dn = $this->search_userdn($rcmail, $ds);
        }

        if (empty($user_dn)) {
            ldap_unbind($ds);
            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 = $user_dn;
            $bindpw = $curpass;
            break;
        }

        $crypted_pass = $this->hash_password($passwd, $rcmail->config->get('password_ldap_encodage'));
        $lchattr      = $rcmail->config->get('password_ldap_lchattr');
        $pwattr       = $rcmail->config->get('password_ldap_pwattr');
        $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 = $this->hash_password($passwd, 'samba'))) {
            return PASSWORD_CRYPT_ERROR;
        }

        // Bind
        if (!ldap_bind($ds, $binddn, $bindpw)) {
            ldap_unbind($ds);
            return PASSWORD_CONNECT_ERROR;
        }

        $entree[$pwattr] = $crypted_pass;

        // Update PasswordLastChange Attribute if desired
        if ($lchattr) {
            $entree[$lchattr] = (int)(time() / 86400);
        }

        // Update Samba password
        if ($smbpwattr) {
            $entree[$smbpwattr] = $samba_pass;
        }

        // Update Samba password last change
        if ($smblchattr) {
            $entree[$smblchattr] = time();
        }

        if (!ldap_modify($ds, $user_dn, $entree)) {
            ldap_unbind($ds);
            return PASSWORD_CONNECT_ERROR;
        }

        // All done, no error
        ldap_unbind($ds);
        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, $ds)
    {
        /* Bind */
        if (!ldap_bind($ds, $rcmail->config->get('password_ldap_searchDN'), $rcmail->config->get('password_ldap_searchPW'))) {
            return false;
        }

        /* Search for the DN */
        if (!$sr = ldap_search($ds, $rcmail->config->get('password_ldap_search_base'), $this->substitute_vars($rcmail->config->get('password_ldap_search_filter')))) {
            return false;
        }

        /* If no or more entries were found, return false */
        if (ldap_count_entries($ds, $sr) != 1) {
            return false;
        }

        return ldap_get_dn($ds, ldap_first_entry($ds, $sr));
    }

    /**
     * Substitute %login, %name, %domain, %dc in $str
     * See plugin config for details
     */
    function substitute_vars($str)
    {
        $str = str_replace('%login', $_SESSION['username'], $str);
        $str = str_replace('%l', $_SESSION['username'], $str);

        $parts = explode('@', $_SESSION['username']);

        if (count($parts) == 2) {
            $dc = 'dc='.strtr($parts[1], array('.' => ',dc=')); // hierarchal domain string

            $str = str_replace('%name', $parts[0], $str);
            $str = str_replace('%n', $parts[0], $str);
            $str = str_replace('%dc', $dc, $str);
            $str = str_replace('%domain', $parts[1], $str);
            $str = str_replace('%d', $parts[1], $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
     */
    function hash_password($password_clear, $encodage_type)
    {
        $encodage_type = strtolower($encodage_type);
        switch ($encodage_type) {
        case 'crypt':
            $crypted_password = '{CRYPT}' . crypt($password_clear, $this->random_salt(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;
            }
            $crypted_password = '{CRYPT}' . crypt($password_clear, '_' . $this->random_salt(8));
            break;
        case 'md5crypt':
            if (!defined('CRYPT_MD5') || CRYPT_MD5 == 0) {
                /* Your system crypt library does not support md5crypt encryption */
                return false;
            }
            $crypted_password = '{CRYPT}' . crypt($password_clear, '$1$' . $this->random_salt(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 */
            $crypted_password = '{CRYPT}' . crypt($password_clear, '$2a$12$' . $this->random_salt(13));
            break;
        case 'md5':
            $crypted_password = '{MD5}' . base64_encode(pack('H*', md5($password_clear)));
            break;
        case 'sha':
            if (function_exists('sha1')) {
                /* Use PHP 4.3.0+ sha1 function, if it is available */
                $crypted_password = '{SHA}' . base64_encode(pack('H*', sha1($password_clear)));
            } else if (function_exists('mhash')) {
                $crypted_password = '{SHA}' . base64_encode(mhash(MHASH_SHA1, $password_clear));
            } else {
                /* Your PHP install does not have the mhash() function */
                return false;
            }
            break;
        case 'ssha':
            if (function_exists('mhash') && function_exists('mhash_keygen_s2k')) {
                mt_srand((double) microtime() * 1000000 );
                $salt = mhash_keygen_s2k(MHASH_SHA1, $password_clear, substr(pack('h*', md5(mt_rand())), 0, 8), 4);
                $crypted_password = '{SSHA}' . base64_encode(mhash(MHASH_SHA1, $password_clear . $salt) . $salt);
            } else {
                /* Your PHP install does not have the mhash() function */
                return false;
            }
            break;
        case 'smd5':
            if (function_exists('mhash') && function_exists('mhash_keygen_s2k')) {
                mt_srand((double) microtime() * 1000000 );
                $salt = mhash_keygen_s2k(MHASH_MD5, $password_clear, substr(pack('h*', md5(mt_rand())), 0, 8), 4);
                $crypted_password = '{SMD5}' . base64_encode(mhash(MHASH_MD5, $password_clear . $salt) . $salt);
            } else {
                /* Your PHP install does not have the mhash() function */
                return false;
            }
            break;
        case 'samba':
            if (function_exists('hash')) {
                $crypted_password = hash('md4', rcube_charset_convert($password_clear, RCMAIL_CHARSET, 'UTF-16LE'));
                $crypted_password = strtoupper($crypted_password);
            } else {
                /* Your PHP install does not have the hash() function */
                return false;
            }
            break;
        case 'clear':
        default:
            $crypted_password = $password_clear;
        }

        return $crypted_password;
    }

    /**
     * Code originaly from the phpLDAPadmin development team
     * http://phpldapadmin.sourceforge.net/
     *
     * Used to generate a random salt for crypt-style passwords
     */
    function random_salt($length)
    {
        $possible = '0123456789' . 'abcdefghijklmnopqrstuvwxyz' . 'ABCDEFGHIJKLMNOPQRSTUVWXYZ' . './';
        $str = '';
        // mt_srand((double)microtime() * 1000000);

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

        return $str;
    }
}
