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forgejo/services/auth/source/ldap/source_search.go
Pavel Ezhov 98770d3db8
Fix group filter for ldap source sync (#22506)
There are 2 separate flows of creating a user: authentication and source
sync.
When a group filter is defined, source sync ignores group filter, while
authentication respects it.
With this PR I've fixed this behavior, so both flows now apply this
filter when searching users in LDAP in a unified way.

- Unified LDAP group membership lookup for authentication and source
sync flows
- Replaced custom group membership lookup (used for authentication flow)
with an existing listLdapGroupMemberships method (used for source sync
flow)
- Modified listLdapGroupMemberships and getUserAttributeListedInGroup in
a way group lookup could be called separately
- Added user filtering based on a group membership for a source sync
- Added tests to cover this logic

Co-authored-by: Pavel Ezhov <paejov@gmail.com>
Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>
2023-02-02 15:45:00 +08:00

562 lines
16 KiB
Go

// Copyright 2014 The Gogs Authors. All rights reserved.
// Copyright 2020 The Gitea Authors. All rights reserved.
// SPDX-License-Identifier: MIT
package ldap
import (
"crypto/tls"
"fmt"
"net"
"strconv"
"strings"
"code.gitea.io/gitea/modules/json"
"code.gitea.io/gitea/modules/log"
"code.gitea.io/gitea/modules/util"
"github.com/go-ldap/ldap/v3"
)
// SearchResult : user data
type SearchResult struct {
Username string // Username
Name string // Name
Surname string // Surname
Mail string // E-mail address
SSHPublicKey []string // SSH Public Key
IsAdmin bool // if user is administrator
IsRestricted bool // if user is restricted
LowerName string // LowerName
Avatar []byte
LdapTeamAdd map[string][]string // organizations teams to add
LdapTeamRemove map[string][]string // organizations teams to remove
}
func (source *Source) sanitizedUserQuery(username string) (string, bool) {
// See http://tools.ietf.org/search/rfc4515
badCharacters := "\x00()*\\"
if strings.ContainsAny(username, badCharacters) {
log.Debug("'%s' contains invalid query characters. Aborting.", username)
return "", false
}
return fmt.Sprintf(source.Filter, username), true
}
func (source *Source) sanitizedUserDN(username string) (string, bool) {
// See http://tools.ietf.org/search/rfc4514: "special characters"
badCharacters := "\x00()*\\,='\"#+;<>"
if strings.ContainsAny(username, badCharacters) {
log.Debug("'%s' contains invalid DN characters. Aborting.", username)
return "", false
}
return fmt.Sprintf(source.UserDN, username), true
}
func (source *Source) sanitizedGroupFilter(group string) (string, bool) {
// See http://tools.ietf.org/search/rfc4515
badCharacters := "\x00*\\"
if strings.ContainsAny(group, badCharacters) {
log.Trace("Group filter invalid query characters: %s", group)
return "", false
}
return group, true
}
func (source *Source) sanitizedGroupDN(groupDn string) (string, bool) {
// See http://tools.ietf.org/search/rfc4514: "special characters"
badCharacters := "\x00()*\\'\"#+;<>"
if strings.ContainsAny(groupDn, badCharacters) || strings.HasPrefix(groupDn, " ") || strings.HasSuffix(groupDn, " ") {
log.Trace("Group DN contains invalid query characters: %s", groupDn)
return "", false
}
return groupDn, true
}
func (source *Source) findUserDN(l *ldap.Conn, name string) (string, bool) {
log.Trace("Search for LDAP user: %s", name)
// A search for the user.
userFilter, ok := source.sanitizedUserQuery(name)
if !ok {
return "", false
}
log.Trace("Searching for DN using filter %s and base %s", userFilter, source.UserBase)
search := ldap.NewSearchRequest(
source.UserBase, ldap.ScopeWholeSubtree, ldap.NeverDerefAliases, 0, 0,
false, userFilter, []string{}, nil)
// Ensure we found a user
sr, err := l.Search(search)
if err != nil || len(sr.Entries) < 1 {
log.Debug("Failed search using filter[%s]: %v", userFilter, err)
return "", false
} else if len(sr.Entries) > 1 {
log.Debug("Filter '%s' returned more than one user.", userFilter)
return "", false
}
userDN := sr.Entries[0].DN
if userDN == "" {
log.Error("LDAP search was successful, but found no DN!")
return "", false
}
return userDN, true
}
func dial(source *Source) (*ldap.Conn, error) {
log.Trace("Dialing LDAP with security protocol (%v) without verifying: %v", source.SecurityProtocol, source.SkipVerify)
tlsConfig := &tls.Config{
ServerName: source.Host,
InsecureSkipVerify: source.SkipVerify,
}
if source.SecurityProtocol == SecurityProtocolLDAPS {
return ldap.DialTLS("tcp", net.JoinHostPort(source.Host, strconv.Itoa(source.Port)), tlsConfig)
}
conn, err := ldap.Dial("tcp", net.JoinHostPort(source.Host, strconv.Itoa(source.Port)))
if err != nil {
return nil, fmt.Errorf("error during Dial: %w", err)
}
if source.SecurityProtocol == SecurityProtocolStartTLS {
if err = conn.StartTLS(tlsConfig); err != nil {
conn.Close()
return nil, fmt.Errorf("error during StartTLS: %w", err)
}
}
return conn, nil
}
func bindUser(l *ldap.Conn, userDN, passwd string) error {
log.Trace("Binding with userDN: %s", userDN)
err := l.Bind(userDN, passwd)
if err != nil {
log.Debug("LDAP auth. failed for %s, reason: %v", userDN, err)
return err
}
log.Trace("Bound successfully with userDN: %s", userDN)
return err
}
func checkAdmin(l *ldap.Conn, ls *Source, userDN string) bool {
if len(ls.AdminFilter) == 0 {
return false
}
log.Trace("Checking admin with filter %s and base %s", ls.AdminFilter, userDN)
search := ldap.NewSearchRequest(
userDN, ldap.ScopeWholeSubtree, ldap.NeverDerefAliases, 0, 0, false, ls.AdminFilter,
[]string{ls.AttributeName},
nil)
sr, err := l.Search(search)
if err != nil {
log.Error("LDAP Admin Search with filter %s for %s failed unexpectedly! (%v)", ls.AdminFilter, userDN, err)
} else if len(sr.Entries) < 1 {
log.Trace("LDAP Admin Search found no matching entries.")
} else {
return true
}
return false
}
func checkRestricted(l *ldap.Conn, ls *Source, userDN string) bool {
if len(ls.RestrictedFilter) == 0 {
return false
}
if ls.RestrictedFilter == "*" {
return true
}
log.Trace("Checking restricted with filter %s and base %s", ls.RestrictedFilter, userDN)
search := ldap.NewSearchRequest(
userDN, ldap.ScopeWholeSubtree, ldap.NeverDerefAliases, 0, 0, false, ls.RestrictedFilter,
[]string{ls.AttributeName},
nil)
sr, err := l.Search(search)
if err != nil {
log.Error("LDAP Restrictred Search with filter %s for %s failed unexpectedly! (%v)", ls.RestrictedFilter, userDN, err)
} else if len(sr.Entries) < 1 {
log.Trace("LDAP Restricted Search found no matching entries.")
} else {
return true
}
return false
}
// List all group memberships of a user
func (source *Source) listLdapGroupMemberships(l *ldap.Conn, uid string, applyGroupFilter bool) []string {
var ldapGroups []string
var searchFilter string
groupFilter, ok := source.sanitizedGroupFilter(source.GroupFilter)
if !ok {
return ldapGroups
}
groupDN, ok := source.sanitizedGroupDN(source.GroupDN)
if !ok {
return ldapGroups
}
if applyGroupFilter {
searchFilter = fmt.Sprintf("(&(%s)(%s=%s))", groupFilter, source.GroupMemberUID, ldap.EscapeFilter(uid))
} else {
searchFilter = fmt.Sprintf("(%s=%s)", source.GroupMemberUID, ldap.EscapeFilter(uid))
}
result, err := l.Search(ldap.NewSearchRequest(
groupDN,
ldap.ScopeWholeSubtree,
ldap.NeverDerefAliases,
0,
0,
false,
searchFilter,
[]string{},
nil,
))
if err != nil {
log.Error("Failed group search in LDAP with filter [%s]: %v", searchFilter, err)
return ldapGroups
}
for _, entry := range result.Entries {
if entry.DN == "" {
log.Error("LDAP search was successful, but found no DN!")
continue
}
ldapGroups = append(ldapGroups, entry.DN)
}
return ldapGroups
}
// parse LDAP groups and return map of ldap groups to organizations teams
func (source *Source) mapLdapGroupsToTeams() map[string]map[string][]string {
ldapGroupsToTeams := make(map[string]map[string][]string)
err := json.Unmarshal([]byte(source.GroupTeamMap), &ldapGroupsToTeams)
if err != nil {
log.Error("Failed to unmarshall LDAP teams map: %v", err)
return ldapGroupsToTeams
}
return ldapGroupsToTeams
}
// getMappedMemberships : returns the organizations and teams to modify the users membership
func (source *Source) getMappedMemberships(usersLdapGroups []string, uid string) (map[string][]string, map[string][]string) {
// unmarshall LDAP group team map from configs
ldapGroupsToTeams := source.mapLdapGroupsToTeams()
membershipsToAdd := map[string][]string{}
membershipsToRemove := map[string][]string{}
for group, memberships := range ldapGroupsToTeams {
isUserInGroup := util.SliceContainsString(usersLdapGroups, group)
if isUserInGroup {
for org, teams := range memberships {
membershipsToAdd[org] = teams
}
} else if !isUserInGroup {
for org, teams := range memberships {
membershipsToRemove[org] = teams
}
}
}
return membershipsToAdd, membershipsToRemove
}
func (source *Source) getUserAttributeListedInGroup(entry *ldap.Entry) string {
if strings.ToLower(source.UserUID) == "dn" {
return entry.DN
}
return entry.GetAttributeValue(source.UserUID)
}
// SearchEntry : search an LDAP source if an entry (name, passwd) is valid and in the specific filter
func (source *Source) SearchEntry(name, passwd string, directBind bool) *SearchResult {
// See https://tools.ietf.org/search/rfc4513#section-5.1.2
if len(passwd) == 0 {
log.Debug("Auth. failed for %s, password cannot be empty", name)
return nil
}
l, err := dial(source)
if err != nil {
log.Error("LDAP Connect error, %s:%v", source.Host, err)
source.Enabled = false
return nil
}
defer l.Close()
var userDN string
if directBind {
log.Trace("LDAP will bind directly via UserDN template: %s", source.UserDN)
var ok bool
userDN, ok = source.sanitizedUserDN(name)
if !ok {
return nil
}
err = bindUser(l, userDN, passwd)
if err != nil {
return nil
}
if source.UserBase != "" {
// not everyone has a CN compatible with input name so we need to find
// the real userDN in that case
userDN, ok = source.findUserDN(l, name)
if !ok {
return nil
}
}
} else {
log.Trace("LDAP will use BindDN.")
var found bool
if source.BindDN != "" && source.BindPassword != "" {
err := l.Bind(source.BindDN, source.BindPassword)
if err != nil {
log.Debug("Failed to bind as BindDN[%s]: %v", source.BindDN, err)
return nil
}
log.Trace("Bound as BindDN %s", source.BindDN)
} else {
log.Trace("Proceeding with anonymous LDAP search.")
}
userDN, found = source.findUserDN(l, name)
if !found {
return nil
}
}
if !source.AttributesInBind {
// binds user (checking password) before looking-up attributes in user context
err = bindUser(l, userDN, passwd)
if err != nil {
return nil
}
}
userFilter, ok := source.sanitizedUserQuery(name)
if !ok {
return nil
}
isAttributeSSHPublicKeySet := len(strings.TrimSpace(source.AttributeSSHPublicKey)) > 0
isAtributeAvatarSet := len(strings.TrimSpace(source.AttributeAvatar)) > 0
attribs := []string{source.AttributeUsername, source.AttributeName, source.AttributeSurname, source.AttributeMail}
if len(strings.TrimSpace(source.UserUID)) > 0 {
attribs = append(attribs, source.UserUID)
}
if isAttributeSSHPublicKeySet {
attribs = append(attribs, source.AttributeSSHPublicKey)
}
if isAtributeAvatarSet {
attribs = append(attribs, source.AttributeAvatar)
}
log.Trace("Fetching attributes '%v', '%v', '%v', '%v', '%v', '%v', '%v' with filter '%s' and base '%s'", source.AttributeUsername, source.AttributeName, source.AttributeSurname, source.AttributeMail, source.AttributeSSHPublicKey, source.AttributeAvatar, source.UserUID, userFilter, userDN)
search := ldap.NewSearchRequest(
userDN, ldap.ScopeWholeSubtree, ldap.NeverDerefAliases, 0, 0, false, userFilter,
attribs, nil)
sr, err := l.Search(search)
if err != nil {
log.Error("LDAP Search failed unexpectedly! (%v)", err)
return nil
} else if len(sr.Entries) < 1 {
if directBind {
log.Trace("User filter inhibited user login.")
} else {
log.Trace("LDAP Search found no matching entries.")
}
return nil
}
var sshPublicKey []string
var Avatar []byte
username := sr.Entries[0].GetAttributeValue(source.AttributeUsername)
firstname := sr.Entries[0].GetAttributeValue(source.AttributeName)
surname := sr.Entries[0].GetAttributeValue(source.AttributeSurname)
mail := sr.Entries[0].GetAttributeValue(source.AttributeMail)
teamsToAdd := make(map[string][]string)
teamsToRemove := make(map[string][]string)
// Check group membership
if source.GroupsEnabled {
userAttributeListedInGroup := source.getUserAttributeListedInGroup(sr.Entries[0])
usersLdapGroups := source.listLdapGroupMemberships(l, userAttributeListedInGroup, true)
if source.GroupFilter != "" && len(usersLdapGroups) == 0 {
return nil
}
if source.GroupTeamMap != "" || source.GroupTeamMapRemoval {
teamsToAdd, teamsToRemove = source.getMappedMemberships(usersLdapGroups, userAttributeListedInGroup)
}
}
if isAttributeSSHPublicKeySet {
sshPublicKey = sr.Entries[0].GetAttributeValues(source.AttributeSSHPublicKey)
}
isAdmin := checkAdmin(l, source, userDN)
var isRestricted bool
if !isAdmin {
isRestricted = checkRestricted(l, source, userDN)
}
if isAtributeAvatarSet {
Avatar = sr.Entries[0].GetRawAttributeValue(source.AttributeAvatar)
}
if !directBind && source.AttributesInBind {
// binds user (checking password) after looking-up attributes in BindDN context
err = bindUser(l, userDN, passwd)
if err != nil {
return nil
}
}
return &SearchResult{
LowerName: strings.ToLower(username),
Username: username,
Name: firstname,
Surname: surname,
Mail: mail,
SSHPublicKey: sshPublicKey,
IsAdmin: isAdmin,
IsRestricted: isRestricted,
Avatar: Avatar,
LdapTeamAdd: teamsToAdd,
LdapTeamRemove: teamsToRemove,
}
}
// UsePagedSearch returns if need to use paged search
func (source *Source) UsePagedSearch() bool {
return source.SearchPageSize > 0
}
// SearchEntries : search an LDAP source for all users matching userFilter
func (source *Source) SearchEntries() ([]*SearchResult, error) {
l, err := dial(source)
if err != nil {
log.Error("LDAP Connect error, %s:%v", source.Host, err)
source.Enabled = false
return nil, err
}
defer l.Close()
if source.BindDN != "" && source.BindPassword != "" {
err := l.Bind(source.BindDN, source.BindPassword)
if err != nil {
log.Debug("Failed to bind as BindDN[%s]: %v", source.BindDN, err)
return nil, err
}
log.Trace("Bound as BindDN %s", source.BindDN)
} else {
log.Trace("Proceeding with anonymous LDAP search.")
}
userFilter := fmt.Sprintf(source.Filter, "*")
isAttributeSSHPublicKeySet := len(strings.TrimSpace(source.AttributeSSHPublicKey)) > 0
isAtributeAvatarSet := len(strings.TrimSpace(source.AttributeAvatar)) > 0
attribs := []string{source.AttributeUsername, source.AttributeName, source.AttributeSurname, source.AttributeMail, source.UserUID}
if isAttributeSSHPublicKeySet {
attribs = append(attribs, source.AttributeSSHPublicKey)
}
if isAtributeAvatarSet {
attribs = append(attribs, source.AttributeAvatar)
}
log.Trace("Fetching attributes '%v', '%v', '%v', '%v', '%v', '%v' with filter %s and base %s", source.AttributeUsername, source.AttributeName, source.AttributeSurname, source.AttributeMail, source.AttributeSSHPublicKey, source.AttributeAvatar, userFilter, source.UserBase)
search := ldap.NewSearchRequest(
source.UserBase, ldap.ScopeWholeSubtree, ldap.NeverDerefAliases, 0, 0, false, userFilter,
attribs, nil)
var sr *ldap.SearchResult
if source.UsePagedSearch() {
sr, err = l.SearchWithPaging(search, source.SearchPageSize)
} else {
sr, err = l.Search(search)
}
if err != nil {
log.Error("LDAP Search failed unexpectedly! (%v)", err)
return nil, err
}
result := make([]*SearchResult, 0, len(sr.Entries))
for _, v := range sr.Entries {
teamsToAdd := make(map[string][]string)
teamsToRemove := make(map[string][]string)
if source.GroupsEnabled {
userAttributeListedInGroup := source.getUserAttributeListedInGroup(v)
if source.GroupFilter != "" {
usersLdapGroups := source.listLdapGroupMemberships(l, userAttributeListedInGroup, true)
if len(usersLdapGroups) == 0 {
continue
}
}
if source.GroupTeamMap != "" || source.GroupTeamMapRemoval {
usersLdapGroups := source.listLdapGroupMemberships(l, userAttributeListedInGroup, false)
teamsToAdd, teamsToRemove = source.getMappedMemberships(usersLdapGroups, userAttributeListedInGroup)
}
}
user := &SearchResult{
Username: v.GetAttributeValue(source.AttributeUsername),
Name: v.GetAttributeValue(source.AttributeName),
Surname: v.GetAttributeValue(source.AttributeSurname),
Mail: v.GetAttributeValue(source.AttributeMail),
IsAdmin: checkAdmin(l, source, v.DN),
LdapTeamAdd: teamsToAdd,
LdapTeamRemove: teamsToRemove,
}
if !user.IsAdmin {
user.IsRestricted = checkRestricted(l, source, v.DN)
}
if isAttributeSSHPublicKeySet {
user.SSHPublicKey = v.GetAttributeValues(source.AttributeSSHPublicKey)
}
if isAtributeAvatarSet {
user.Avatar = v.GetRawAttributeValue(source.AttributeAvatar)
}
user.LowerName = strings.ToLower(user.Username)
result = append(result, user)
}
return result, nil
}