<?php

require_once('inc/base.php');
require_once('inc/security.php');

define("CERT_OK", 0);
define("CERT_INVALID", 1);
define("CERT_NOCHAIN", 2);

function user_certs()
{
  $uid = (int) $_SESSION['userinfo']['uid'];
  $result = db_query("SELECT id, valid_from, valid_until, subject, cn FROM vhosts.certs WHERE uid=${uid}");
  $ret = array();
  while ($i = mysql_fetch_assoc($result))
    $ret[] = $i;
  DEBUG($ret);
  return $ret;
}

function user_csr()
{
  $uid = (int) $_SESSION['userinfo']['uid'];
  $result = db_query("SELECT id, created, hostname, bits FROM vhosts.csr WHERE uid=${uid}");
  $ret = array();
  while ($i = mysql_fetch_assoc($result))
    $ret[] = $i;
  DEBUG($ret);
  return $ret;
}

function cert_details($id)
{
  $id = (int) $id;
  $uid = (int) $_SESSION['userinfo']['uid'];
  
  $result = db_query("SELECT id, lastchange, valid_from, valid_until, subject, cn, cert, `key` FROM vhosts.certs WHERE uid={$uid} AND id={$id}");
  if (mysql_num_rows($result) != 1)
    system_failure("Ungültiges Zertifikat #{$id}");
  return mysql_fetch_assoc($result);
}


function csr_details($id)
{
  $id = (int) $id;
  $uid = (int) $_SESSION['userinfo']['uid'];
  
  $result = db_query("SELECT id, created, hostname, bits, csr, `key` FROM vhosts.csr WHERE uid={$uid} AND id={$id}");
  if (mysql_num_rows($result) != 1)
    system_failure("Ungültiger CSR");
  return mysql_fetch_assoc($result);
}


function get_available_CAs()
{
  $path = '/etc/apache2/certs/cabundle/';
  $ret = glob($path.'*.pem');
  if (! $ret)
    system_failure("Konnte die CA-Zertifikate nicht laden");
  DEBUG($ret);
  return $ret;
}


function get_chain($cert)
{
  $certdata = openssl_x509_parse($cert, true);
  if ($certdata === FALSE) {
    system_failure("Das Zertifikat konnte nicht gelesen werden");
  }
  if (! isset($certdata['issuer']['CN'])) {
    return NULL;
  }
  $issuer = mysql_real_escape_string($certdata['issuer']['CN']);
  $result = db_query("SELECT id FROM vhosts.certchain WHERE cn='{$issuer}'");
  if (mysql_num_rows($result) > 0)
  {
    $c = mysql_fetch_assoc($result);
    //$chainfile = '/etc/apache2/certs/chains/'.$c['id'].'.pem';
    DEBUG("identified fitting certificate chain #".$c['id']);
    return $c['id'];
  }
}


function validate_certificate($cert, $key)
{ 
  // Lade private key 
  $seckey = openssl_get_privatekey($key);
  if ($seckey === FALSE) {
    system_failure("Der private Schlüssel konnte (ohne Passwort) nicht gelesen werden.");
  }
  // Lade public key
  $pubkey = openssl_get_publickey($cert);
  if ($pubkey === FALSE) {
    system_failure("In dem eingetragenen Zertifikat wurde kein öffentlicher Schlüssel gefunden.");
  }
  // Parse Details über den pubkey
  $certinfo = openssl_pkey_get_details($pubkey);
  DEBUG($certinfo);
  if ($certinfo === FALSE) {
    system_failure("Der öffentliche Schlüssel des Zertifikats konnte nicht gelesen werden");
  }

  // Apache unterstützt nur Schlüssel vom Typ RSA oder DSA
  if (! in_array($certinfo['type'], array(OPENSSL_KEYTYPE_RSA, OPENSSL_KEYTYPE_DSA))) {
    system_failure("Dieser Schlüssel nutzt einen nicht unterstützten Algorithmus.");
  }
    
  // Bei ECC-Keys treten kürzere Schlüssellängen auf, die können wir aktuell aber sowieso nicht unterstützen
  if ($certinfo['bits'] < 2048) {
    warning("Dieser Schlüssel hat eine sehr geringe Bitlänge und ist daher als nicht besonders sicher einzustufen!");
  }

  // Prüfe ob Key und Zertifikat zusammen passen
  if (openssl_x509_check_private_key($cert, $key) !== true)
  {
    DEBUG("Zertifikat und Key passen nicht zusammen");
    return CERT_INVALID;
  }

  $cacerts = array('/etc/ssl/certs');
  $chain = get_chain($cert);
  if ($chain)
  {
    $cacerts[] = '/etc/apache2/certs/chains/'.$chain.'.pem';
  }

  if (openssl_x509_checkpurpose($cert, X509_PURPOSE_SSL_SERVER, $cacerts) !== true)
  { 
    DEBUG('certificate was not validated as a server certificate with the available chain');
    return CERT_NOCHAIN;
  }

  return CERT_OK;
}


function parse_cert_details($cert)
{
  $certdata = openssl_x509_parse($cert, true);
  /* 
name => /CN=*.bwurst.org
validFrom_time_t => 1204118790
validTo_time_t => 1267190790


  */
  DEBUG($certdata);
  //return array('subject' => $certdata['name'], 'cn' => $certdata['subject']['CN'], 'valid_from' => date('Y-m-d', $certdata['validFrom_time_t']), 'valid_until' => date('Y-m-d', $certdata['validTo_time_t']));
  return array('subject' => $certdata['subject']['CN'].' / '.$certdata['issuer']['O'], 'cn' => $certdata['subject']['CN'], 'valid_from' => date('Y-m-d', $certdata['validFrom_time_t']), 'valid_until' => date('Y-m-d', $certdata['validTo_time_t']), 'issuer' => $certdata['issuer']['CN']);
}


function save_cert($info, $cert, $key)
{
  openssl_pkey_export($key, $key);
  openssl_x509_export($cert, $cert);
  $subject = mysql_real_escape_string(filter_input_general($info['subject']));
  $cn = mysql_real_escape_string(filter_input_general($info['cn']));
  $valid_from = mysql_real_escape_string($info['valid_from']);
  $valid_until = mysql_real_escape_string($info['valid_until']);
  $chain = maybe_null( get_chain($cert) );
  $cert = mysql_real_escape_string($cert);
  $key = mysql_real_escape_string($key);
  $uid = (int) $_SESSION['userinfo']['uid'];

  db_query("INSERT INTO vhosts.certs (uid, subject, cn, valid_from, valid_until, chain, cert, `key`) VALUES ({$uid}, '{$subject}', '{$cn}', '{$valid_from}', '{$valid_until}', {$chain}, '{$cert}', '{$key}')");
}


function refresh_cert($id, $info, $cert, $key = NULL)
{
  openssl_x509_export($cert, $cert);
  $chain = maybe_null( get_chain($cert) );

  $id = (int) $id;
  $oldcert = cert_details($id);
  $cert = mysql_real_escape_string($cert);
  
  $valid_from = mysql_real_escape_string($info['valid_from']);
  $valid_until = mysql_real_escape_string($info['valid_until']);

  $keyop = '';
  if ($key) {
    openssl_pkey_export($key, $key);
    $keyop = ", `key`='".mysql_real_escape_string($key)."'";
  }
  db_query("UPDATE vhosts.certs SET cert='{$cert}'{$keyop}, valid_from='{$valid_from}', valid_until='{$valid_until}', chain={$chain} WHERE id={$id} LIMIT 1");
}


function delete_cert($id)
{
  $uid = (int) $_SESSION['userinfo']['uid'];
  $id = (int) $id;
  
  db_query("DELETE FROM vhosts.certs WHERE uid={$uid} AND id={$id} LIMIT 1");
}

function delete_csr($id)
{
  $uid = (int) $_SESSION['userinfo']['uid'];
  $id = (int) $id;
  
  db_query("DELETE FROM vhosts.csr WHERE uid={$uid} AND id={$id} LIMIT 1");
}

function create_wildcard_csr($cn, $bits)
{
  $cn = filter_input_hostname($cn);
  $bits = (int) $bits;
  if ($bits == 0)
    $bits = 4096;

  $keyfile = tempnam(ini_get('upload_tmp_dir'), 'key');
  $csrfile = tempnam(ini_get('upload_tmp_dir'), 'csr');
  $config = tempnam(ini_get('upload_tmp_dir'), 'config');

  DEBUG("key: ".$keyfile." / csr: ".$csrfile." / config: ".$config);

  $c = fopen($config, "w");
  fwrite($c, "[req]
default_bits = {$bits}
default_keyfile = {$keyfile}
encrypt_key = no
distinguished_name      = req_distinguished_name
req_extensions = v3_req

[v3_req]
subjectAltName = DNS:{$cn}, DNS:*.{$cn}

[ req_distinguished_name ]
countryName                     = Country Name (2 letter code)
countryName_default             = DE
stateOrProvinceName             = State or Province Name (full name)
stateOrProvinceName_default     = Baden-Wuerttemberg
localityName                    = Locality Name (eg, city)
localityName_default            = Murrhardt
0.organizationName              = Organization Name (eg, company)
0.organizationName_default      = schokokeks.org

commonName = Common Name
commonName_default = *.{$cn}
");
  fclose($c);

  $output = '';
  $cmdline = "openssl req -sha256 -new -batch -config {$config} -out {$csrfile}";
  $retval = 0;
  exec($cmdline, $output, $retval);
  DEBUG($output);
  DEBUG($retval);
  if ($retval != 0)
  {
    system_failure("Die Erzeugung des CSR ist fehlgeschlagen. Ausgabe des OpenSSL-Befehls: ".print_r($output, true));
  }
  
  $csr = file_get_contents($csrfile);
  $key = file_get_contents($keyfile);

  unlink($csrfile);
  unlink($keyfile);
  unlink($config);

  return array($csr, $key);
}


function create_csr($cn, $bits)
{
  $cn = filter_input_hostname($cn);
  $bits = (int) $bits;
  if ($bits == 0)
    $bits = 4096;

  $keyfile = tempnam(ini_get('upload_tmp_dir'), 'key');
  $csrfile = tempnam(ini_get('upload_tmp_dir'), 'csr');
  $config = tempnam(ini_get('upload_tmp_dir'), 'config');

  DEBUG("key: ".$keyfile." / csr: ".$csrfile." / config: ".$config);

  $c = fopen($config, "w");
  fwrite($c, "[req]
default_bits = {$bits}
default_keyfile = {$keyfile}
encrypt_key = no
distinguished_name      = req_distinguished_name

[ req_distinguished_name ]
countryName                     = Country Name (2 letter code)
countryName_default             = DE
stateOrProvinceName             = State or Province Name (full name)
stateOrProvinceName_default     = Baden-Wuerttemberg
localityName                    = Locality Name (eg, city)
localityName_default            = Murrhardt
0.organizationName              = Organization Name (eg, company)
0.organizationName_default      = schokokeks.org

commonName = Common Name
commonName_default = {$cn}
");
  fclose($c);

  $output = '';
  $cmdline = "openssl req -sha256 -new -batch -config {$config} -out {$csrfile}";
  $retval = 0;
  exec($cmdline, $output, $retval);
  DEBUG($output);
  DEBUG($retval);
  if ($retval != 0)
  {
    system_failure("Die Erzeugung des CSR ist fehlgeschlagen. Ausgabe des OpenSSL-Befehls: ".print_r($output, true));
  }
  
  $csr = file_get_contents($csrfile);
  $key = file_get_contents($keyfile);

  unlink($csrfile);
  unlink($keyfile);
  unlink($config);

  return array($csr, $key);
}


function save_csr($cn, $bits, $wildcard=true)
{
  $csr = NULL;
  $key = NULL;
  if ($wildcard)
    list($csr, $key) = create_wildcard_csr($cn, $bits);
  else
    list($csr, $key) = create_csr($cn, $bits);
  
  $uid = (int) $_SESSION['userinfo']['uid'];
  $cn = mysql_real_escape_string(filter_input_hostname($cn));
  $bits = (int) $bits;
  $csr = mysql_real_escape_string($csr);
  $key = mysql_real_escape_string($key);
  db_query("INSERT INTO vhosts.csr (uid, hostname, bits, csr, `key`) VALUES ({$uid}, '{$cn}', {$bits}, '{$csr}', '{$key}')");
  $id = mysql_insert_id();
  return $id;  
}