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[stable21] fix detecting cyclic group memberships #25843

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Merged
rullzer merged 1 commit into from
Mar 3, 2021
Merged

[stable21] fix detecting cyclic group memberships #25843

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31 changes: 21 additions & 10 deletions apps/user_ldap/lib/Group_LDAP.php
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Original file line number Diff line number Diff line change
Expand Up @@ -245,6 +245,9 @@ public function getDynamicGroupMembers(string $dnGroup): array {
private function _groupMembers(string $dnGroup, ?array &$seen = null): array {
if ($seen === null) {
$seen = [];
// the root entry has to be marked as processed to avoind infinit loops,
// but not included in the results laters on
$excludeFromResult = $dnGroup;
}
$allMembers = [];
if (array_key_exists($dnGroup, $seen)) {
Expand Down Expand Up @@ -290,13 +293,19 @@ private function _groupMembers(string $dnGroup, ?array &$seen = null): array {
$seen[$dnGroup] = 1;
$members = $this->access->readAttribute($dnGroup, $this->access->connection->ldapGroupMemberAssocAttr);
if (is_array($members)) {
$fetcher = function ($memberDN, &$seen) {
$fetcher = function ($memberDN) use (&$seen) {
return $this->_groupMembers($memberDN, $seen);
};
$allMembers = $this->walkNestedGroups($dnGroup, $fetcher, $members);
$allMembers = $this->walkNestedGroups($dnGroup, $fetcher, $members, $seen);
}

$allMembers += $this->getDynamicGroupMembers($dnGroup);
if (isset($excludeFromResult)) {
$index = array_search($excludeFromResult, $allMembers, true);
if ($index !== false) {
unset($allMembers[$index]);
}
}

$this->access->connection->writeToCache($cacheKey, $allMembers);
if (isset($attemptedLdapMatchingRuleInChain)
Expand Down Expand Up @@ -335,7 +344,7 @@ private function _getGroupDNsFromMemberOf(string $dn): array {
return $this->filterValidGroups($groups);
}

private function walkNestedGroups(string $dn, Closure $fetcher, array $list): array {
private function walkNestedGroups(string $dn, Closure $fetcher, array $list, array &$seen = []): array {
$nesting = (int)$this->access->connection->ldapNestedGroups;
// depending on the input, we either have a list of DNs or a list of LDAP records
// also, the output expects either DNs or records. Testing the first element should suffice.
Expand All @@ -354,19 +363,21 @@ private function walkNestedGroups(string $dn, Closure $fetcher, array $list): ar
return $list;
}

$seen = [];
while ($record = array_shift($list)) {
$recordDN = $recordMode ? $record['dn'][0] : $record;
$recordDN = $record['dn'][0] ?? $record;
if ($recordDN === $dn || array_key_exists($recordDN, $seen)) {
// Prevent loops
continue;
}
$fetched = $fetcher($record, $seen);
$fetched = $fetcher($record);
$list = array_merge($list, $fetched);
$seen[$recordDN] = $record;
if (!isset($seen[$recordDN]) || is_bool($seen[$recordDN]) && is_array($record)) {
$seen[$recordDN] = $record;
}
}

return $recordMode ? $seen : array_keys($seen);
// on record mode, filter out intermediate state
return $recordMode ? array_filter($seen, 'is_array') : array_keys($seen);
}

/**
Expand Down Expand Up @@ -841,7 +852,7 @@ private function getGroupsByMember(string $dn, array &$seen = null): array {
$groups = $this->access->fetchListOfGroups($filter,
[strtolower($this->access->connection->ldapGroupMemberAssocAttr), $this->access->connection->ldapGroupDisplayName, 'dn']);
if (is_array($groups)) {
$fetcher = function ($dn, &$seen) {
$fetcher = function ($dn) use (&$seen) {
if (is_array($dn) && isset($dn['dn'][0])) {
$dn = $dn['dn'][0];
}
Expand All @@ -852,7 +863,7 @@ private function getGroupsByMember(string $dn, array &$seen = null): array {
$dn = "";
}

$allGroups = $this->walkNestedGroups($dn, $fetcher, $groups);
$allGroups = $this->walkNestedGroups($dn, $fetcher, $groups, $seen);
}
$visibleGroups = $this->filterValidGroups($allGroups);
return array_intersect_key($allGroups, $visibleGroups);
Expand Down