add user/group DNs to config

README.md

@@ -353,6 +353,9 @@ settings:
   auth_mode: required
   ldap_bind_address: ldaps://ad01.example.com:636
   ldap_base_dn: DC=example,DC=com
+  # Optional performance scopes; default to ldap_base_dn when omitted.
+  ldap_user_base_dn: OU=Users,DC=example,DC=com
+  ldap_group_base_dn: OU=Groups,DC=example,DC=com
   auth_group_role_mappings:
     "CN=vctp-viewers,OU=Groups,DC=example,DC=com": viewer
     "CN=vctp-admins,OU=Groups,DC=example,DC=com": admin
@@ -511,6 +514,8 @@ Authentication:
 - `settings.ldap_groups` empty/omitted means no allowlist filter, but mapped-role requirement still applies.
 - `settings.ldap_bind_address`: LDAP/LDAPS URL used for authentication.
 - `settings.ldap_base_dn`: LDAP base DN for user/group lookups.
+- `settings.ldap_user_base_dn`: optional user lookup base DN; defaults to `settings.ldap_base_dn`.
+- `settings.ldap_group_base_dn`: optional group lookup base DN; defaults to `settings.ldap_base_dn`.
 - `settings.ldap_trust_cert_file`: optional CA cert file for LDAP TLS.
 - `settings.ldap_disable_validation`: disables LDAP TLS cert validation.
 - `settings.ldap_insecure`: insecure LDAP TLS mode.

internal/auth/ldap.go

@@ -25,6 +25,8 @@ var (
 type LDAPConfig struct {
 	BindAddress       string
 	BaseDN            string
+	UserBaseDN        string
+	GroupBaseDN       string
 	TrustCertFile     string
 	DisableValidation bool
 	Insecure          bool
@@ -45,6 +47,8 @@ type LDAPIdentity struct {
 type LDAPAuthenticator struct {
 	bindAddress       string
 	baseDN            string
+	userBaseDN        string
+	groupBaseDN       string
 	trustCertFile     string
 	disableValidation bool
 	insecure          bool
@@ -54,6 +58,8 @@ type LDAPAuthenticator struct {
 func NewLDAPAuthenticator(cfg LDAPConfig) (*LDAPAuthenticator, error) {
 	bindAddress := strings.TrimSpace(cfg.BindAddress)
 	baseDN := strings.TrimSpace(cfg.BaseDN)
+	userBaseDN := strings.TrimSpace(cfg.UserBaseDN)
+	groupBaseDN := strings.TrimSpace(cfg.GroupBaseDN)
 	trustCertFile := strings.TrimSpace(cfg.TrustCertFile)
 
 	if bindAddress == "" {
@@ -62,6 +68,12 @@ func NewLDAPAuthenticator(cfg LDAPConfig) (*LDAPAuthenticator, error) {
 	if baseDN == "" {
 		return nil, fmt.Errorf("%w: base DN is required", ErrInvalidLDAPConfig)
 	}
+	if userBaseDN == "" {
+		userBaseDN = baseDN
+	}
+	if groupBaseDN == "" {
+		groupBaseDN = baseDN
+	}
 	if _, err := url.ParseRequestURI(bindAddress); err != nil {
 		return nil, fmt.Errorf("%w: bind address must be a valid URL: %v", ErrInvalidLDAPConfig, err)
 	}
@@ -74,6 +86,8 @@ func NewLDAPAuthenticator(cfg LDAPConfig) (*LDAPAuthenticator, error) {
 	return &LDAPAuthenticator{
 		bindAddress:       bindAddress,
 		baseDN:            baseDN,
+		userBaseDN:        userBaseDN,
+		groupBaseDN:       groupBaseDN,
 		trustCertFile:     trustCertFile,
 		disableValidation: cfg.DisableValidation,
 		insecure:          cfg.Insecure,
@@ -119,6 +133,10 @@ func (a *LDAPAuthenticator) AuthenticateAndFetchGroups(ctx context.Context, user
 	if rewrittenToUPN {
 		identity.Diagnostics = append(identity.Diagnostics, "bind_username_rewritten_to_upn")
 	}
+	identity.Diagnostics = append(identity.Diagnostics,
+		"user_lookup_base_dn="+a.userBaseDN,
+		"group_lookup_base_dn="+a.groupBaseDN,
+	)
 	if whoami, err := conn.WhoAmI(nil); err != nil {
 		identity.Diagnostics = append(identity.Diagnostics, fmt.Sprintf("whoami_failed:%v", err))
 	} else if boundDN := parseWhoAmIDN(whoami.AuthzID); boundDN != "" {
@@ -131,7 +149,7 @@ func (a *LDAPAuthenticator) AuthenticateAndFetchGroups(ctx context.Context, user
 	}
 
 	userLookupStartedAt := time.Now()
-	entry, lookupStrategy, err := a.lookupUserEntry(conn, bindUsername, identity.UserDN)
+	entry, lookupStrategy, err := a.lookupUserEntry(conn, inputUsername, identity.UserDN)
 	identity.UserLookupDuration = time.Since(userLookupStartedAt)
 	identity.Diagnostics = append(identity.Diagnostics, fmt.Sprintf("user_lookup_duration_ms=%d", identity.UserLookupDuration.Milliseconds()))
 	if err != nil {
@@ -329,6 +347,9 @@ func (a *LDAPAuthenticator) lookupUserEntry(conn *ldap.Conn, username string, us
 			if entry != nil {
 				return entry, "principal_upn", nil
 			}
+			// For UPN principals, avoid fallback attribute probes that are unlikely to match
+			// and can be expensive on large directory trees.
+			continue
 		}
 
 		entry, err := a.searchUserByAttribute(conn, "sAMAccountName", principal)
@@ -359,7 +380,7 @@ func (a *LDAPAuthenticator) searchUserByAttribute(conn *ldap.Conn, attribute str
 	}
 
 	searchRes, err := conn.Search(ldap.NewSearchRequest(
-		a.baseDN,
+		a.userBaseDN,
 		ldap.ScopeWholeSubtree,
 		ldap.NeverDerefAliases,
 		2,

internal/settings/settings.go

@@ -79,6 +79,8 @@ type SettingsYML struct {
 		LDAPGroups                       []string             `yaml:"ldap_groups"`
 		LDAPBindAddress                  string               `yaml:"ldap_bind_address"`
 		LDAPBaseDN                       string               `yaml:"ldap_base_dn"`
+		LDAPUserBaseDN                   string               `yaml:"ldap_user_base_dn"`
+		LDAPGroupBaseDN                  string               `yaml:"ldap_group_base_dn"`
 		LDAPTrustCertFile                string               `yaml:"ldap_trust_cert_file"`
 		LDAPDisableValidation            bool                 `yaml:"ldap_disable_validation"`
 		LDAPInsecure                     bool                 `yaml:"ldap_insecure"`
@@ -284,6 +286,8 @@ func applyDefaultsAndValidateSettings(cfg *SettingsYML) error {
 	s.AuthJWTSigningKey = strings.TrimSpace(s.AuthJWTSigningKey)
 	s.LDAPBindAddress = strings.TrimSpace(s.LDAPBindAddress)
 	s.LDAPBaseDN = strings.TrimSpace(s.LDAPBaseDN)
+	s.LDAPUserBaseDN = strings.TrimSpace(s.LDAPUserBaseDN)
+	s.LDAPGroupBaseDN = strings.TrimSpace(s.LDAPGroupBaseDN)
 	s.LDAPTrustCertFile = strings.TrimSpace(s.LDAPTrustCertFile)
 	s.LDAPGroups = compactTrimmedStrings(s.LDAPGroups)
 
@@ -340,6 +344,12 @@ func applyDefaultsAndValidateSettings(cfg *SettingsYML) error {
 	if s.LDAPBaseDN == "" {
 		return errors.New("settings.ldap_base_dn is required when settings.auth_enabled=true")
 	}
+	if s.LDAPUserBaseDN == "" {
+		s.LDAPUserBaseDN = s.LDAPBaseDN
+	}
+	if s.LDAPGroupBaseDN == "" {
+		s.LDAPGroupBaseDN = s.LDAPBaseDN
+	}
 	if len(s.AuthGroupRoleMappings) == 0 {
 		return errors.New("settings.auth_group_role_mappings must define at least one mapping when settings.auth_enabled=true")
 	}

internal/settings/settings_strict_test.go

@@ -193,6 +193,12 @@ func TestReadYMLSettingsAcceptsValidAuthConfigAndNormalizesMappings(t *testing.T
 	if len(got.LDAPGroups) != 1 || got.LDAPGroups[0] != "cn=vctp-viewers,ou=groups,dc=example,dc=com" {
 		t.Fatalf("expected ldap_groups to be compacted+trimmed, got %#v", got.LDAPGroups)
 	}
+	if got.LDAPUserBaseDN != "dc=example,dc=com" {
+		t.Fatalf("expected default ldap_user_base_dn to fall back to ldap_base_dn, got %q", got.LDAPUserBaseDN)
+	}
+	if got.LDAPGroupBaseDN != "dc=example,dc=com" {
+		t.Fatalf("expected default ldap_group_base_dn to fall back to ldap_base_dn, got %q", got.LDAPGroupBaseDN)
+	}
 	if got.AuthGroupRoleMappings["cn=vctp-admins,ou=groups,dc=example,dc=com"] != authRoleAdmin {
 		t.Fatalf("expected admin mapping to normalize role to %q, got %#v", authRoleAdmin, got.AuthGroupRoleMappings)
 	}

server/handler/auth.go

@@ -85,6 +85,8 @@ func (h *Handler) AuthLogin(w http.ResponseWriter, r *http.Request) {
 		"username", username,
 		"ldap_bind_address", cfg.LDAPBindAddress,
 		"ldap_base_dn", cfg.LDAPBaseDN,
+		"ldap_user_base_dn", cfg.LDAPUserBaseDN,
+		"ldap_group_base_dn", cfg.LDAPGroupBaseDN,
 		"ldap_group_requirements", limitStrings(cfg.LDAPGroups, maxDebugLogListItems),
 		"auth_group_role_mapping_keys", limitStrings(sortedStringMapKeys(cfg.AuthGroupRoleMappings), maxDebugLogListItems),
 		"ldap_insecure", cfg.LDAPInsecure,
@@ -95,6 +97,8 @@ func (h *Handler) AuthLogin(w http.ResponseWriter, r *http.Request) {
 	ldapAuth, err := newLDAPAuthenticator(auth.LDAPConfig{
 		BindAddress:       cfg.LDAPBindAddress,
 		BaseDN:            cfg.LDAPBaseDN,
+		UserBaseDN:        cfg.LDAPUserBaseDN,
+		GroupBaseDN:       cfg.LDAPGroupBaseDN,
 		TrustCertFile:     cfg.LDAPTrustCertFile,
 		DisableValidation: cfg.LDAPDisableValidation,
 		Insecure:          cfg.LDAPInsecure,