authelia/internal/authentication/ldap_user_provider.go
James Elliott f292050822
fix(authentication): ldap connection left open (#2179)
The recent ldap changes in cb71df5 left a connection to the LDAP server open at startup. This resolves this which prevents an ugly log message and unnecessary open sockets.
2021-07-13 21:12:50 +10:00

378 lines
11 KiB
Go

package authentication
import (
"crypto/tls"
"crypto/x509"
"fmt"
"strings"
"github.com/go-ldap/ldap/v3"
"github.com/sirupsen/logrus"
"golang.org/x/text/encoding/unicode"
"github.com/authelia/authelia/internal/configuration/schema"
"github.com/authelia/authelia/internal/logging"
"github.com/authelia/authelia/internal/utils"
)
// LDAPUserProvider is a provider using a LDAP or AD as a user database.
type LDAPUserProvider struct {
configuration schema.LDAPAuthenticationBackendConfiguration
tlsConfig *tls.Config
dialOpts ldap.DialOpt
logger *logrus.Logger
connectionFactory LDAPConnectionFactory
usersBaseDN string
groupsBaseDN string
supportExtensionPasswdModify bool
}
// NewLDAPUserProvider creates a new instance of LDAPUserProvider.
func NewLDAPUserProvider(configuration schema.AuthenticationBackendConfiguration, certPool *x509.CertPool) (provider *LDAPUserProvider, err error) {
provider = newLDAPUserProvider(*configuration.LDAP, certPool, nil)
err = provider.checkServer()
if err != nil {
return provider, err
}
if !provider.supportExtensionPasswdModify && !configuration.DisableResetPassword &&
provider.configuration.Implementation != schema.LDAPImplementationActiveDirectory {
provider.logger.Warnf("Your LDAP server implementation may not support a method for password hashing " +
"known to Authelia, it's strongly recommended you ensure your directory server hashes the password " +
"attribute when users reset their password via Authelia.")
}
return provider, nil
}
func newLDAPUserProvider(configuration schema.LDAPAuthenticationBackendConfiguration, certPool *x509.CertPool, factory LDAPConnectionFactory) (provider *LDAPUserProvider) {
if configuration.TLS == nil {
configuration.TLS = schema.DefaultLDAPAuthenticationBackendConfiguration.TLS
}
tlsConfig := utils.NewTLSConfig(configuration.TLS, tls.VersionTLS12, certPool)
var dialOpts ldap.DialOpt
if tlsConfig != nil {
dialOpts = ldap.DialWithTLSConfig(tlsConfig)
}
if factory == nil {
factory = NewLDAPConnectionFactoryImpl()
}
provider = &LDAPUserProvider{
configuration: configuration,
tlsConfig: tlsConfig,
dialOpts: dialOpts,
logger: logging.Logger(),
connectionFactory: factory,
}
provider.parseDynamicConfiguration()
return provider
}
func (p *LDAPUserProvider) parseDynamicConfiguration() {
p.configuration.UsersFilter = strings.ReplaceAll(p.configuration.UsersFilter, "{username_attribute}", p.configuration.UsernameAttribute)
p.configuration.UsersFilter = strings.ReplaceAll(p.configuration.UsersFilter, "{mail_attribute}", p.configuration.MailAttribute)
p.configuration.UsersFilter = strings.ReplaceAll(p.configuration.UsersFilter, "{display_name_attribute}", p.configuration.DisplayNameAttribute)
p.logger.Tracef("Dynamically generated users filter is %s", p.configuration.UsersFilter)
if p.configuration.AdditionalUsersDN != "" {
p.usersBaseDN = p.configuration.AdditionalUsersDN + "," + p.configuration.BaseDN
} else {
p.usersBaseDN = p.configuration.BaseDN
}
p.logger.Tracef("Dynamically generated users BaseDN is %s", p.usersBaseDN)
if p.configuration.AdditionalGroupsDN != "" {
p.groupsBaseDN = ldap.EscapeFilter(p.configuration.AdditionalGroupsDN + "," + p.configuration.BaseDN)
} else {
p.groupsBaseDN = p.configuration.BaseDN
}
p.logger.Tracef("Dynamically generated groups BaseDN is %s", p.groupsBaseDN)
}
func (p *LDAPUserProvider) checkServer() (err error) {
conn, err := p.connect(p.configuration.User, p.configuration.Password)
if err != nil {
return err
}
defer conn.Close()
searchRequest := ldap.NewSearchRequest("", ldap.ScopeBaseObject, ldap.NeverDerefAliases,
1, 0, false, "(objectClass=*)", []string{ldapSupportedExtensionAttribute}, nil)
sr, err := conn.Search(searchRequest)
if err != nil {
return err
}
if len(sr.Entries) != 1 {
return nil
}
// Iterate the attribute values to see what the server supports.
for _, attr := range sr.Entries[0].Attributes {
if attr.Name == ldapSupportedExtensionAttribute {
p.logger.Tracef("LDAP Supported Extension OIDs: %s", strings.Join(attr.Values, ", "))
for _, oid := range attr.Values {
if oid == ldapOIDPasswdModifyExtension {
p.supportExtensionPasswdModify = true
break
}
}
break
}
}
return nil
}
func (p *LDAPUserProvider) connect(userDN string, password string) (LDAPConnection, error) {
conn, err := p.connectionFactory.DialURL(p.configuration.URL, p.dialOpts)
if err != nil {
return nil, err
}
if p.configuration.StartTLS {
if err := conn.StartTLS(p.tlsConfig); err != nil {
return nil, err
}
}
if err := conn.Bind(userDN, password); err != nil {
return nil, err
}
return conn, nil
}
// CheckUserPassword checks if provided password matches for the given user.
func (p *LDAPUserProvider) CheckUserPassword(inputUsername string, password string) (bool, error) {
conn, err := p.connect(p.configuration.User, p.configuration.Password)
if err != nil {
return false, err
}
defer conn.Close()
profile, err := p.getUserProfile(conn, inputUsername)
if err != nil {
return false, err
}
userConn, err := p.connect(profile.DN, password)
if err != nil {
return false, fmt.Errorf("Authentication of user %s failed. Cause: %s", inputUsername, err)
}
defer userConn.Close()
return true, nil
}
func (p *LDAPUserProvider) ldapEscape(inputUsername string) string {
inputUsername = ldap.EscapeFilter(inputUsername)
for _, c := range specialLDAPRunes {
inputUsername = strings.ReplaceAll(inputUsername, string(c), fmt.Sprintf("\\%c", c))
}
return inputUsername
}
type ldapUserProfile struct {
DN string
Emails []string
DisplayName string
Username string
}
func (p *LDAPUserProvider) resolveUsersFilter(userFilter string, inputUsername string) string {
inputUsername = p.ldapEscape(inputUsername)
// The {input} placeholder is replaced by the users username input.
userFilter = strings.ReplaceAll(userFilter, "{input}", inputUsername)
p.logger.Tracef("Computed user filter is %s", userFilter)
return userFilter
}
func (p *LDAPUserProvider) getUserProfile(conn LDAPConnection, inputUsername string) (*ldapUserProfile, error) {
userFilter := p.resolveUsersFilter(p.configuration.UsersFilter, inputUsername)
attributes := []string{"dn",
p.configuration.DisplayNameAttribute,
p.configuration.MailAttribute,
p.configuration.UsernameAttribute}
// Search for the given username.
searchRequest := ldap.NewSearchRequest(
p.usersBaseDN, ldap.ScopeWholeSubtree, ldap.NeverDerefAliases,
1, 0, false, userFilter, attributes, nil,
)
sr, err := conn.Search(searchRequest)
if err != nil {
return nil, fmt.Errorf("Cannot find user DN of user %s. Cause: %s", inputUsername, err)
}
if len(sr.Entries) == 0 {
return nil, ErrUserNotFound
}
if len(sr.Entries) > 1 {
return nil, fmt.Errorf("Multiple users %s found", inputUsername)
}
userProfile := ldapUserProfile{
DN: sr.Entries[0].DN,
}
for _, attr := range sr.Entries[0].Attributes {
if attr.Name == p.configuration.DisplayNameAttribute {
userProfile.DisplayName = attr.Values[0]
}
if attr.Name == p.configuration.MailAttribute {
userProfile.Emails = attr.Values
}
if attr.Name == p.configuration.UsernameAttribute {
if len(attr.Values) != 1 {
return nil, fmt.Errorf("User %s cannot have multiple value for attribute %s",
inputUsername, p.configuration.UsernameAttribute)
}
userProfile.Username = attr.Values[0]
}
}
if userProfile.DN == "" {
return nil, fmt.Errorf("No DN has been found for user %s", inputUsername)
}
return &userProfile, nil
}
func (p *LDAPUserProvider) resolveGroupsFilter(inputUsername string, profile *ldapUserProfile) (string, error) { //nolint:unparam
inputUsername = p.ldapEscape(inputUsername)
// The {input} placeholder is replaced by the users username input.
groupFilter := strings.ReplaceAll(p.configuration.GroupsFilter, "{input}", inputUsername)
if profile != nil {
groupFilter = strings.ReplaceAll(groupFilter, "{username}", ldap.EscapeFilter(profile.Username))
groupFilter = strings.ReplaceAll(groupFilter, "{dn}", ldap.EscapeFilter(profile.DN))
}
p.logger.Tracef("Computed groups filter is %s", groupFilter)
return groupFilter, nil
}
// GetDetails retrieve the groups a user belongs to.
func (p *LDAPUserProvider) GetDetails(inputUsername string) (*UserDetails, error) {
conn, err := p.connect(p.configuration.User, p.configuration.Password)
if err != nil {
return nil, err
}
defer conn.Close()
profile, err := p.getUserProfile(conn, inputUsername)
if err != nil {
return nil, err
}
groupsFilter, err := p.resolveGroupsFilter(inputUsername, profile)
if err != nil {
return nil, fmt.Errorf("Unable to create group filter for user %s. Cause: %s", inputUsername, err)
}
// Search for the given username.
searchGroupRequest := ldap.NewSearchRequest(
p.groupsBaseDN, ldap.ScopeWholeSubtree, ldap.NeverDerefAliases,
0, 0, false, groupsFilter, []string{p.configuration.GroupNameAttribute}, nil,
)
sr, err := conn.Search(searchGroupRequest)
if err != nil {
return nil, fmt.Errorf("Unable to retrieve groups of user %s. Cause: %s", inputUsername, err)
}
groups := make([]string, 0)
for _, res := range sr.Entries {
if len(res.Attributes) == 0 {
p.logger.Warningf("No groups retrieved from LDAP for user %s", inputUsername)
break
}
// Append all values of the document. Normally there should be only one per document.
groups = append(groups, res.Attributes[0].Values...)
}
return &UserDetails{
Username: profile.Username,
DisplayName: profile.DisplayName,
Emails: profile.Emails,
Groups: groups,
}, nil
}
// UpdatePassword update the password of the given user.
func (p *LDAPUserProvider) UpdatePassword(inputUsername string, newPassword string) error {
conn, err := p.connect(p.configuration.User, p.configuration.Password)
if err != nil {
return fmt.Errorf("Unable to update password. Cause: %s", err)
}
defer conn.Close()
profile, err := p.getUserProfile(conn, inputUsername)
if err != nil {
return fmt.Errorf("Unable to update password. Cause: %s", err)
}
switch {
case p.supportExtensionPasswdModify:
modifyRequest := ldap.NewPasswordModifyRequest(
profile.DN,
"",
newPassword,
)
err = conn.PasswordModify(modifyRequest)
case p.configuration.Implementation == schema.LDAPImplementationActiveDirectory:
modifyRequest := ldap.NewModifyRequest(profile.DN, nil)
utf16 := unicode.UTF16(unicode.LittleEndian, unicode.IgnoreBOM)
// The password needs to be enclosed in quotes
// https://docs.microsoft.com/en-us/openspecs/windows_protocols/ms-adts/6e803168-f140-4d23-b2d3-c3a8ab5917d2
pwdEncoded, _ := utf16.NewEncoder().String(fmt.Sprintf("\"%s\"", newPassword))
modifyRequest.Replace("unicodePwd", []string{pwdEncoded})
err = conn.Modify(modifyRequest)
default:
modifyRequest := ldap.NewModifyRequest(profile.DN, nil)
modifyRequest.Replace("userPassword", []string{newPassword})
err = conn.Modify(modifyRequest)
}
if err != nil {
return fmt.Errorf("Unable to update password. Cause: %s", err)
}
return nil
}