<?php

/*  Poweradmin, a friendly web-based admin tool for PowerDNS.
 *  See <http://www.poweradmin.org> for more details.
 *
 *  Copyright 2007-2009  Rejo Zenger <rejo@zenger.nl>
 *  Copyright 2010-2014  Poweradmin Development Team
 *      <http://www.poweradmin.org/credits.html>
 *
 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

/**
 * DNSSEC functions
 *
 * @package Poweradmin
 * @copyright   2007-2010 Rejo Zenger <rejo@zenger.nl>
 * @copyright   2010-2014 Poweradmin Development Team
 * @license     http://opensource.org/licenses/GPL-3.0 GPL
 */

/** Check if it's possible to execute dnssec command
 *
 * @return boolean true on success, false on failure
 */
function is_pdnssec_callable() {
    global $pdnssec_command;

    if (!function_exists('exec')) {
        error(ERR_EXEC_NOT_ALLOWED);
        return false;
    }

    if (!file_exists($pdnssec_command) || !is_executable($pdnssec_command)) {
        error(ERR_EXEC_PDNSSEC);
        return false;
    }

    return true;
}

/** Execute dnssec utility
 *
 * @return mixed[] Array with output from command execution and error code
 */
function call_dnssec($command, $args) {
    global $pdnssec_command;
    $output = '';
    $return_code = -1;

    if (!is_pdnssec_callable()) {
        return array($output, $return_code);
    }

    $command = join(' ', array(
        $pdnssec_command,
        $command,
        $args)
    );

    exec($command, $output, $return_code);

    return array($output, $return_code);
}

/** Execute PDNSSEC rectify-zone command for Domain ID
 *
 * If a Domain is dnssec enabled, or uses features as
 * e.g. ALSO-NOTIFY, ALLOW-AXFR-FROM, TSIG-ALLOW-AXFR
 * following has to be executed
 * pdnssec rectify-zone $domain
 *
 * @param int $domain_id Domain ID
 *
 * @return boolean true on success, false on failure or unnecessary
 */
function dnssec_rectify_zone($domain_id) {
    global $db;
    global $pdnssec_command;

    $output = array();

    /* if pdnssec_command is set we perform ``pdnssec rectify-zone $domain`` on all zones,
     * as pdns needs the "auth" column for all zones if dnssec is enabled
     *
     * If there is any entry at domainmetadata table for this domain,
     * it is an error if pdnssec_command is not set */
    $query = "SELECT COUNT(id) FROM domainmetadata WHERE domain_id = " . $db->quote($domain_id, 'integer');
    $count = $db->queryOne($query);

    if (PEAR::isError($count)) {
        error($count->getMessage());
        return false;
    }

    if (isset($pdnssec_command)) {
        $domain = get_zone_name_from_id($domain_id);
        $command = $pdnssec_command . " rectify-zone " . $domain;

        if (!is_pdnssec_callable()) {
            return false;
        }

        exec($command, $output, $return_code);
        if ($return_code != 0) {
            error(ERR_EXEC_PDNSSEC_RECTIFY_ZONE);
            return false;
        }

        return true;
    } else if ($count >= 1) {
        error(ERR_EXEC_PDNSSEC);
        return false;
    }

    return false;
}

/** Execute PDNSSEC secure-zone command for Domain Name
 *
 * @param string $domain_name Domain Name
 *
 * @return boolean true on success, false on failure or unnecessary
 */
function dnssec_secure_zone($domain_name) {
    $call_result = call_dnssec('secure-zone', $domain_name);
    $return_code = $call_result[1];

    if ($return_code != 0) {
        error(ERR_EXEC_PDNSSEC_SECURE_ZONE);
        return false;
    }

    return true;
}

/** Execute PDNSSEC disable-dnssec command for Domain Name
 *
 * @param string $domain_name Domain Name
 *
 * @return boolean true on success, false on failure or unnecessary
 */
function dnssec_unsecure_zone($domain_name) {
    $call_result = call_dnssec('disable-dnssec', $domain_name);
    $return_code = $call_result[1];

    if ($return_code != 0) {
        error(ERR_EXEC_PDNSSEC_DISABLE_ZONE);
        return false;
    }

    return true;
}

/** Check if zone is secured
 *
 * @param string $domain_name Domain Name
 *
 * @return boolean true on success, false on failure
 */
function dnssec_is_zone_secured($domain_name) {
    $call_result = call_dnssec('show-zone', $domain_name);
    $output = $call_result[0];
    $return_code = $call_result[1];

    if ($return_code != 0) {
        error(ERR_EXEC_PDNSSEC_SHOW_ZONE);
        return false;
    }

    return (count($output) == 0 ? false : true);
}

/** Use presigned RRSIGs from storage
 *
 * @param string $domain_name Domain Name
 */
function dnssec_set_nsec3($domain_name) {
    call_dnssec('set-nsec3', $domain_name);
}

/** Switch back to NSEC
 *
 * @param string $domain_name Domain Name
 */
function dnssec_unset_nsec3($domain_name) {
    call_dnssec('unset-nsec3', $domain_name);
}

/** Return nsec type
 *
 * @param string $domain_name Domain Name
 *
 * @return string nsec or nsec3
 */
function dnssec_get_nsec_type($domain_name) {
    $call_result = call_dnssec('show-zone', $domain_name);
    $output = $call_result[0];

    return ($output[0] == 'Zone has NSEC semantics' ? 'nsec' : 'nsec3');
}

/** Use presigned RRSIGs from storage
 *
 * @param string $domain_name Domain Name
 */
function dnssec_set_presigned($domain_name) {
    call_dnssec('set-presigned', $domain_name);
}

/** No longer use presigned RRSIGs
 *
 * @param string $domain_name Domain Name
 */
function dnssec_unset_presigned($domain_name) {
    call_dnssec('unset-presigned', $domain_name);
}

/** Return presigned status
 *
 * @param string $domain_name Domain Name
 *
 * @return boolean true if zone is presigned, otherwise false
 */
function dnssec_get_presigned_status($domain_name) {
    $call_result = call_dnssec('show-zone', $domain_name);
    $output = $call_result[0];

    return ($output[1] == 'Zone is presigned' ? true : false);
}

/** Rectify all zones.
 */
function dnssec_rectify_all_zones() {
    call_dnssec('rectify-all-zones', '');
}

/** Return DS records
 *
 * @param string $domain_name Domain Name
 *
 * @return mixed[] DS records
 */
function dnssec_ds_records($domain_name) {
    $call_result = call_dnssec('show-zone', $domain_name);
    $output = $call_result[0];
    $return_code = $call_result[1];

    if ($return_code != 0) {
        error(ERR_EXEC_PDNSSEC_SHOW_ZONE);
        return false;
    }

    $ds_records = array();
    foreach ($output as $line) {
        if (substr($line, 0, 2) == 'DS') {
            $items = explode(' ', $line);
            $ds_line = join(" ", array_slice($items, 2));
            $ds_records[] = $ds_line;
        }
    }

    return $ds_records;
}

/** Return algorithm name for given number
 *
 * @param int $algo Algorithm id
 *
 * @return string algorithm name
 */
function dnssec_algorithm_to_name($algo) {
    $name = 'Unallocated/Reserved';

    switch ($algo) {
        case 0:
            $name = 'Reserved';
            break;
        case 1:
            $name = 'RSAMD5';
            break;
        case 2:
            $name = 'DH';
            break;
        case 3:
            $name = 'DSA';
            break;
        case 4:
            $name = 'ECC';
            break;
        case 5:
            $name = 'RSASHA1';
            break;
        case 6:
            $name = 'DSA-NSEC3-SHA1';
            break;
        case 7:
            $name = 'RSASHA1-NSEC3-SHA1';
            break;
        case 8:
            $name = 'RSASHA256';
            break;
        case 9:
            $name = 'Reserved';
            break;
        case 10:
            $name = 'RSASHA512';
            break;
        case 11:
            $name = 'Reserved';
            break;
        case 12:
            $name = 'ECC-GOST';
            break;
        case 13:
            $name = 'ECDSAP256SHA256';
            break;
        case 14:
            $name = 'ECDSAP384SHA384';
            break;
        case 252:
            $name = 'INDIRECT';
            break;
        case 253:
            $name = 'PRIVATEDNS';
            break;
        case 254:
            $name = 'PRIVATEOID';
            break;
    }

    return $name;
}

/** Return algorihtm name for given short name
 *
 * @param string $short_name Short algorithm name
 */
function dnssec_shorthand_to_algorithm_name($short_name) {
    $name = 'Unknown';

    switch ($short_name) {
        case "rsamd5":
            $name = dnssec_algorithm_to_name(1);
            break;
        case "dh":
            $name = dnssec_algorithm_to_name(2);
            break;
        case "dsa":
            $name = dnssec_algorithm_to_name(3);
            break;
        case "ecc":
            $name = dnssec_algorithm_to_name(4);
            break;
        case "rsasha1":
            $name = dnssec_algorithm_to_name(5);
            break;
        case "rsasha256":
            $name = dnssec_algorithm_to_name(8);
            break;
        case "rsasha512":
            $name = dnssec_algorithm_to_name(10);
            break;
        case "gost":
            $name = dnssec_algorithm_to_name(12);
            break;
        case "ecdsa256":
            $name = dnssec_algorithm_to_name(13);
            break;
        case "ecdsa384":
            $name = dnssec_algorithm_to_name(14);
            break;
        case "ed25519":
            $name = dnssec_algorithm_to_name(250);
            break;
    }

    return $name;
}

/** Get name of digest type
 *
 * @param int $type Digest type id
 *
 * @return string digest name
 */
function dnssec_get_digest_name($type) {
    $name = 'Unknown';

    switch ($type) {
        case 1:
            $name = 'SHA-1';
            break;
        case 2:
            $name = 'SHA-256 ';
            break;
    }

    return $name;
}

/** Check if zone is secured
 *
 * @param string $domain_name Domain Name
 *
 * @return string string containing dns key
 */
function dnssec_dnskey_record($domain_name) {
    $call_result = call_dnssec('show-zone', $domain_name);
    $output = $call_result[0];
    $return_code = $call_result[1];

    if ($return_code != 0) {
        error(ERR_EXEC_PDNSSEC_SHOW_ZONE);
        return false;
    }

    $dns_key = '';
    foreach ($output as $line) {
        if (substr($line, 0, 3) == 'KSK') {
            $items = explode(' ', $line);
            $dns_key = join(" ", array_slice($items, 3));
        }
    }

    return $dns_key;
}

/** Activate zone key
 *
 * @param string $domain_name Domain Name
 *
 * @return boolean true on success, false on failure
 */
function dnssec_activate_zone_key($domain_name, $key_id) {
    $call_result = call_dnssec('activate-zone-key', join(" ", array($domain_name, $key_id)));
    $return_code = $call_result[1];

    if ($return_code != 0) {
        error(ERR_EXEC_PDNSSEC_SHOW_ZONE);
        return false;
    }

    return true;
}

/** Deactivate zone key
 *
 * @param string $domain_name Domain Name
 *
 * @return boolean true on success, false on failure
 */
function dnssec_deactivate_zone_key($domain_name, $key_id) {
    $call_result = call_dnssec('deactivate-zone-key', join(" ", array($domain_name, $key_id)));
    $return_code = $call_result[1];

    if ($return_code != 0) {
        error(ERR_EXEC_PDNSSEC_SHOW_ZONE);
        return false;
    }

    return true;
}

/** Get list of existing DNSSEC keys
 *
 * @param string $domain_name Domain Name
 *
 * @return mixed[] array with DNSSEC keys
 */
function dnssec_get_keys($domain_name) {
    $call_result = call_dnssec('show-zone', $domain_name);
    $output = $call_result[0];
    $return_code = $call_result[1];

    if ($return_code != 0) {
        error(ERR_EXEC_PDNSSEC_SHOW_ZONE);
        return false;
    }

    $keys = array();
    foreach ($output as $line) {
        if (substr($line, 0, 2) == 'ID') {
            $items = explode(' ', $line);
            $bits_array = explode("\t", $items[12]);
            $keys[] = array($items[2], substr($items[3], 1, -2), substr($items[6], 0, -1), substr($items[9], 0, -1), $bits_array[0], $items[13]);
        }
    }

    return $keys;
}

/** Create new DNSSEC key
 *
 * @param string $domain_name Domain Name
 * @param string $key_type Key type
 * @param string $bits Bits in length
 * @param string $algorithm Algorithm
 *
 * @return boolean true on success, false on failure
 */
function dnssec_add_zone_key($domain_name, $key_type, $bits, $algorithm) {
    $call_result = call_dnssec('add-zone-key', join(" ", array($domain_name, $key_type, $bits, $algorithm)));
    $return_code = $call_result[1];

    if ($return_code != 0) {
        error(ERR_EXEC_PDNSSEC_ADD_ZONE_KEY);
        return false;
    }

    return true;
}

/** Remove DNSSEC key
 *
 * @param string $domain_name Domain Name
 * @param int $key_id Key ID
 *
 * @return boolean true on success, false on failure
 */
function dnssec_remove_zone_key($domain_name, $key_id) {
    $call_result = call_dnssec('remove-zone-key', join(" ", array($domain_name, $key_id)));
    $return_code = $call_result[1];

    if ($return_code != 0) {
        error(ERR_EXEC_PDNSSEC_ADD_ZONE_KEY);
        return false;
    }

    return true;
}

/** Check if given key exists
 *
 * @param string $domain_name Domain Name
 * @param int $key_id Key ID
 *
 * @return boolean true if exists, otherwise false
 */
function dnssec_zone_key_exists($domain_name, $key_id) {
    $keys = dnssec_get_keys($domain_name);

    foreach ($keys as $key) {
        if ($key[0] == $key_id) {
            return true;
        }
    }

    return false;
}

/** Return requested key
 *
 * @param string $domain_name Domain Name
 * @param int $key_id Key ID
 *
 * @return mixed[] true if exists, otherwise false
 */
function dnssec_get_zone_key($domain_name, $key_id) {
    $keys = dnssec_get_keys($domain_name);

    foreach ($keys as $key) {
        if ($key[0] == $key_id) {
            return $key;
        }
    }

    return array();
}