Switch LDAP avatar lookups to LDAPS (#95)

api/user_avatar.php connected via ldap://$ldapHost:$ldapPort — never
ldaps://, and there was no ldap_start_tls() call anywhere in the
codebase. LDAP_BIND_PW was sent over the wire unencrypted on every
avatar fetch.

Switched to ldaps://, and changed LDAP_HOST/LDAP_PORT's defaults to
ldap.lotusguild.org:6360 (lldap's LDAPS listener) instead of the bare
IP on port 3890 (plaintext). PHP's ldap extension verifies the server
cert's hostname by default, so a bare IP won't validate against the
LDAPS cert (issued for *.lotusguild.org) — LDAP_HOST has to be a
hostname the cert covers. This is deliberately not configurable back to
plaintext ldap://.

Infra change (pve-infra, separate repo/commit): added a Pi-hole
split-horizon override so ldap.lotusguild.org resolves internally to
the real LDAP server's LAN IP — its existing public DNS record points
elsewhere (an unrelated host), and there was no internal-only DNS entry
for it before this.

Verified against the real lldap server (pct 147, LDAPS on 6360, a live
Let's Encrypt *.lotusguild.org cert): confirmed the Pi-hole override
resolves correctly from hosts using it as their resolver, then ran the
exact ldap_connect/ldap_bind sequence via `php -r` directly on the
production tinker_tickets host (10.10.10.45) with a deliberately wrong
bind password — got "Invalid credentials" (a real LDAP protocol
response), not a transport/TLS error, proving the full connect + TLS
handshake + hostname verification + bind path works end-to-end in the
actual deployment environment.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0117oBw2jN4kALYeS8HPq4zV

.env.example

@@ -74,10 +74,14 @@ TRUSTED_PROXIES=
 ; Timezone (default: America/New_York)
 TIMEZONE=America/New_York
 
-; LDAP / lldap (for user avatar lookups)
+; LDAP / lldap (for user avatar lookups). Connects over LDAPS — 6360 is
+; lldap's default LDAPS port, NOT its plaintext port (3890), since
+; LDAP_BIND_PW below would otherwise go over the wire unencrypted.
+; LDAP_HOST must be a hostname matching the LDAPS cert (TLS hostname
+; verification is not skipped), not a bare IP.
 LDAP_ENABLED=true
-LDAP_HOST=10.10.10.39
+LDAP_HOST=ldap.lotusguild.org
-LDAP_PORT=3890
+LDAP_PORT=6360
 LDAP_BIND_DN="uid=tinker-tickets,ou=people,dc=example,dc=com"
 LDAP_BIND_PW=
 LDAP_BASE_DN="dc=example,dc=com"

api/user_avatar.php

@@ -113,7 +113,10 @@ $avatarData = null;
 $ldapQueryOk = false; // true only if the LDAP lookup completed without error
 
 try {
-    $ldap = @ldap_connect("ldap://$ldapHost:$ldapPort");
+    // LDAPS, not plain ldap:// — LDAP_BIND_PW is sent during ldap_bind() below,
+    // and lldap's plaintext port (3890) would put it on the wire unencrypted.
+    // lldap's LDAPS listener defaults to port 6360 (see config.php).
+    $ldap = @ldap_connect("ldaps://$ldapHost:$ldapPort");
     if (!$ldap) {
         throw new RuntimeException("ldap_connect failed");
     }

config/config.php

@@ -154,9 +154,19 @@ $GLOBALS['config'] = [
     'TIMEZONE' => $envVars['TIMEZONE'] ?? 'America/New_York',
     'TIMEZONE_OFFSET' => null, // Will be calculated below
 
-    // LDAP / lldap settings (for user avatar lookups)
+    // LDAP / lldap settings (for user avatar lookups). Connects over LDAPS
-    'LDAP_HOST'        => $envVars['LDAP_HOST']        ?? '10.10.10.39',
+    // (see api/user_avatar.php) — lldap's default LDAPS port is 6360, not
-    'LDAP_PORT'        => (int)($envVars['LDAP_PORT']  ?? 3890),
+    // its plaintext port 3890. The bind password must never go over the
+    // wire unencrypted, so this is not configurable back to a plaintext
+    // ldap:// connection.
+    //
+    // LDAP_HOST must be a hostname matching the LDAPS cert's *.lotusguild.org
+    // CN/SAN, not a bare IP — PHP's ldap extension verifies the cert's
+    // hostname by default and a mismatch fails the connection. Pi-hole has a
+    // split-horizon override so ldap.lotusguild.org resolves internally to
+    // the real LDAP server IP (its public DNS record points elsewhere).
+    'LDAP_HOST'        => $envVars['LDAP_HOST']        ?? 'ldap.lotusguild.org',
+    'LDAP_PORT'        => (int)($envVars['LDAP_PORT']  ?? 6360),
     'LDAP_BIND_DN'     => $envVars['LDAP_BIND_DN']     ?? 'uid=tinker-tickets,ou=people,dc=example,dc=com',
     'LDAP_BIND_PW'     => $envVars['LDAP_BIND_PW']     ?? '',
     'LDAP_BASE_DN'     => $envVars['LDAP_BASE_DN']     ?? 'dc=example,dc=com',