Do not rely on exop_passwd

lib/LDAPConnect.php

@@ -33,8 +33,11 @@ class LDAPConnect {
  private $ldapConfig;
  /** @var LoggerInterface */
  private $logger;
+ /** @var bool|null */
+ private $passwdSupport;
 
  public function __construct(Helper $ldapBackendHelper, LoggerInterface $logger) {
+ $this->passwdSupport = null;
  $this->logger = $logger;
  $ldapConfigPrefixes = $ldapBackendHelper->getServerConfigurationPrefixes(true);
  $prefix = array_shift($ldapConfigPrefixes);
@@ -143,4 +146,39 @@ public function hasPasswordPolicy(): bool {
  $ppDN = $this->ldapConfig->ldapDefaultPPolicyDN;
  return !empty($ppDN);
  }
+
+ /**
+ * checks whether the LDAP server supports the passwd exop
+ *
+ * @param \LDAP\Connection $connection LDAP connection to check
+ * @return boolean either the user can or cannot
+ */
+ public function hasPasswdExopSupport($connection): bool {
+ // TODO: We should cache this by ldap prefix, but currently we have no access to it.
+ if (is_null($this->passwdSupport)) {
+ $ret = ldap_read($connection, '', '(objectclass=*)', ['supportedExtension']);
+ if ($ret === false) {
+ $this->passwdSupport = false;
+ $this->logger->debug(
+ 'Could not check passwd_exop support of LDAP host, host does not provide the supportedExtension entry.',
+ [ 'app' => Application::APP_ID ]
+ );
+ return false;
+ }
+
+ $ret = ldap_first_entry($connection, $ret);
+ if ($ret === false) {
+ $this->passwdSupport = false;
+ $this->logger->error(
+ 'Could not check passwd_exop support of LDAP host, host returned malformed data for the supported ldap extension entry.',
+ [ 'app' => Application::APP_ID ]
+ );
+ return false;
+ }
+
+ $values = ldap_get_values($connection, $ret, 'supportedExtension');
+ $this->passwdSupport = ($values !== false) && in_array(LDAP_EXOP_MODIFY_PASSWD, $values);
+ }
+ return $this->passwdSupport;
+ }
 }

lib/LDAPUserManager.php

@@ -84,7 +84,7 @@ public function __construct(IUserManager $userManager, IUserSession $userSession
  * @return int bitwise-or'ed actions
  */
  public function respondToActions() {
- $setPassword = function_exists('ldap_exop_passwd') && !$this->ldapConnect->hasPasswordPolicy()
+ $setPassword = $this->canSetPassword() && !$this->ldapConnect->hasPasswordPolicy()
  ? Backend::SET_PASSWORD
  : 0;
 
@@ -140,7 +140,7 @@ public function setDisplayName($uid, $displayName) {
  * checks whether the user is allowed to change his avatar in Nextcloud
  *
  * @param string $uid the Nextcloud user name
- * @return boolean either the user can or cannot
+ * @return bool either the user can or cannot
  */
  public function canChangeAvatar($uid) {
  return $this->configuration->hasAvatarPermission();
@@ -222,7 +222,12 @@ public function createUser($uid, $password) {
  $displayNameAttribute = $this->ldapConnect->getDisplayNameAttribute();
  }
 
+ if ($connection === false) {
+ throw new \Exception('Could not bind to LDAP server');
+ }
+
  [$newUserDN, $newUserEntry] = $this->buildNewEntry($uid, $password, $base);
+
  $newUserDN = $this->ldapProvider->sanitizeDN([$newUserDN])[0];
  $this->ensureAttribute($newUserEntry, $displayNameAttribute, $uid);
 
@@ -244,27 +249,8 @@ public function createUser($uid, $password) {
  throw new \Exception('Cannot create user: ' . ldap_error($connection), ldap_errno($connection));
  }
 
- // Set password through ldap password exop, if supported
  if ($this->respondToActions() & Backend::SET_PASSWORD) {
- try {
- $ret = ldap_exop_passwd($connection, $newUserDN, '', $password);
- if ($ret === false) {
- $message = 'ldap_exop_passwd failed, falling back to ldap_mod_replace to to set password for new user';
- $this->logger->debug($message, ['app' => Application::APP_ID]);
-
- // Fallback to `userPassword` in case the server does not support exop_passwd
- $ret = ldap_mod_replace($connection, $newUserDN, ['userPassword' => $password]);
- if ($ret === false) {
- $message = 'Failed to set password for new user {dn}';
- $this->logger->error($message, [
- 'app' => Application::APP_ID,
- 'dn' => $newUserDN,
- ]);
- }
- }
- } catch (\Exception $e) {
- $this->logger->error($e->getMessage(), ['exception' => $e, 'app' => Application::APP_ID]);
- }
+ $this->handleSetPassword($newUserDN, $password, $connection);
  }
  return $ret ? $newUserDN : false;
  }
@@ -350,6 +336,15 @@ public function deleteUser($uid): bool {
  return $res;
  }
 
+ /**
+ * checks whether the user is allowed to change their password in Nextcloud
+ *
+ * @return bool either the user can or cannot
+ */
+ public function canSetPassword(): bool {
+ return $this->configuration->hasPasswordPermission();
+ }
+
  /**
  * Set password
  *
@@ -360,27 +355,17 @@ public function deleteUser($uid): bool {
  * Change the password of a user
  */
  public function setPassword($uid, $password) {
- if (!function_exists('ldap_exop_passwd')) {
- // since PHP 7.2 – respondToActions checked this already, this
- // method should not be called. Double check due to public scope.
- // This method can be removed when Nextcloud 16 compat is dropped.
- return false;
- }
- try {
- $cr = $this->ldapProvider->getLDAPConnection($uid);
- $userDN = $this->getUserDN($uid);
- return ldap_exop_passwd($cr, $userDN, '', $password) !== false;
- } catch (\Exception $e) {
- $this->logger->error($e->getMessage(), ['exception' => $e, 'app' => Application::APP_ID]);
- }
- return false;
+ $connection = $this->ldapProvider->getLDAPConnection($uid);
+ $userDN = $this->getUserDN($uid);
+
+ return $this->handleSetPassword($userDN, $password, $connection);
  }
 
  /**
  * get the user's home directory
  *
  * @param string $uid the username
- * @return boolean
+ * @return bool
  */
  public function getHome($uid) {
  // Not implemented
@@ -444,4 +429,62 @@ public function changeUserHook(IUser $user, string $feature, $attr1, $attr2): vo
  private function getUserDN($uid): string {
  return $this->ldapProvider->getUserDN($uid);
  }
+
+ /**
+ * Handle setting user password password
+ *
+ * @param string $userDN The username
+ * @param string $password The new password
+ * @param \LDAP\Connection $connection The LDAP connection to use
+ * @return bool
+ *
+ * Change the password of a user
+ */
+ private function handleSetPassword(string $userDN, string $password, \LDAP\Connection $connection): bool {
+ try {
+ $ret = false;
+
+ // try ldap_exop_passwd first
+ if ($this->ldapConnect->hasPasswdExopSupport($connection)) {
+ if (ldap_exop_passwd($connection, $userDN, '', $password) === true) {
+ // `ldap_exop_passwd` is either FALSE or the password, in the later case return TRUE
+ return true;
+ }
+
+ $message = 'Failed to set password for user {dn} using ldap_exop_passwd';
+ $this->logger->error($message, [
+ 'ldap_error' => ldap_error($connection),
+ 'app' => Application::APP_ID,
+ 'dn' => $userDN,
+ ]);
+ } else {
+ // Use ldap_mod_replace in case the server does not support exop_passwd
+ $entry = [];
+ if ($this->configuration->useUnicodePassword()) {
+ $entry['unicodePwd'] = iconv('UTF-8', 'UTF-16LE', '"' . $password . '"');
+ } else {
+ $entry['userPassword'] = $password;
+ }
+
+ if(ldap_mod_replace($connection, $userDN, $entry)) {
+ return true;
+ }
+
+ $message = 'Failed to set password for user {dn} using ldap_mod_replace';
+ $this->logger->error($message, [
+ 'ldap_error' => ldap_error($connection),
+ 'app' => Application::APP_ID,
+ 'dn' => $userDN,
+ ]);
+ }
+ return false;
+ } catch (\Exception $e) {
+ $this->logger->error('Exception occured while setting the password of user {dn}', [
+ 'app' => Application::APP_ID,
+ 'exception' => $e,
+ 'dn' => $userDN,
+ ]);
+ return false;
+ }
+ }
 }

lib/Service/Configuration.php

@@ -48,6 +48,14 @@ public function hasAvatarPermission(): bool {
  return $this->config->getAppValue('ldap_write_support', 'hasAvatarPermission', '1') === '1';
  }
 
+ public function hasPasswordPermission(): bool {
+ return $this->config->getAppValue('ldap_write_support', 'hasPasswordPermission', '1') === '1';
+ }
+
+ public function useUnicodePassword(): bool {
+ return $this->config->getAppValue('ldap_write_support', 'useUnicodePassword', '0') === '1';
+ }
+
  public function getUserTemplate() {
  return $this->config->getAppValue(
  Application::APP_ID,

lib/Settings/Admin.php

@@ -61,8 +61,10 @@ public function getForm() {
  'createRequireActorFromLdap' => $this->config->isLdapActorRequired(),
  'createPreventFallback' => $this->config->isPreventFallback(),
  'hasAvatarPermission' => $this->config->hasAvatarPermission(),
+ 'hasPasswordPermission' => $this->config->hasPasswordPermission(),
  'newUserRequireEmail' => $this->config->isRequireEmail(),
  'newUserGenerateUserID' => $this->config->isGenerateUserId(),
+ 'useUnicodePassword' => $this->config->useUnicodePassword(),
  ]
  );
 

src/components/AdminSettings.vue

@@ -44,6 +44,15 @@
  @change.stop.prevent="toggleSwitch('hasAvatarPermission', !switches.hasAvatarPermission)">
  {{ t('ldap_write_support', 'Allow users to set their avatar') }}
  </NcActionCheckbox>
+ <NcActionCheckbox :checked="switches.hasPasswordPermission"
+ @change.stop.prevent="toggleSwitch('hasPasswordPermission', !switches.hasPasswordPermission)">
+ {{ t('ldap_write_support', 'Allow users to set their password') }}
+ </NcActionCheckbox>
+ <NcActionCheckbox :checked="switches.useUnicodePassword"
+ :title="t('ldap_write_support', 'If the server does not support the modify password extended operation use the `unicodePwd` instead of the `userPassword` attribute for setting the password')"
+ @change.stop.prevent="toggleSwitch('useUnicodePassword', !switches.useUnicodePassword)">
+ {{ t('ldap_write_support', 'Use the `unicodePwd` attribute for setting the user password') }}
+ </NcActionCheckbox>
  </ul>
  <h3>{{ t('ldap_write_support', 'User template') }}</h3>
  <p>{{ t('ldap_write_support', 'LDIF template for creating users. Following placeholders may be used') }}</p>