nuclei/pkg/js/libs/ldap/ldap.go

318 lines
12 KiB
Go

package ldap
import (
"crypto/tls"
"fmt"
"strings"
"github.com/go-ldap/ldap/v3"
"github.com/projectdiscovery/nuclei/v3/pkg/protocols/common/protocolstate"
)
// Client is a client for ldap protocol in golang.
//
// It is a wrapper around the standard library ldap package.
type LdapClient struct {
BaseDN string
Realm string
Host string
Conn *ldap.Conn
Port int
UseSSL bool
TLS bool
}
// Connect is a method for LdapClient that stores information about of the ldap
// connection, tests it and verifies that the server is a valid ldap server
//
// returns the success status
func (c *LdapClient) Connect(host string, port int, ssl, istls bool) (bool, error) {
if c.Conn != nil {
return true, nil
}
if !protocolstate.IsHostAllowed(host) {
// host is not valid according to network policy
return false, protocolstate.ErrHostDenied.Msgf(host)
}
var err error
if ssl {
config := &tls.Config{
InsecureSkipVerify: true,
ServerName: host,
}
c.Conn, err = ldap.DialTLS("tcp", fmt.Sprintf("%s:%d", host, port), config)
} else {
c.Conn, err = ldap.Dial("tcp", fmt.Sprintf("%s:%d", host, port))
}
if err != nil {
return false, err
}
if istls && !ssl {
// Here if it is not a valid ldap server, the StartTLS will return an error,
// so, if this check succeeds, there is no need to check if the host is has an LDAP Server:
// https://github.com/go-ldap/ldap/blob/cdb0754f666833c3e287503ed52d535a41ba10f6/v3/conn.go#L334
if err := c.Conn.StartTLS(&tls.Config{InsecureSkipVerify: true}); err != nil {
return false, err
}
}
c.Host = host
c.Port = port
c.TLS = istls
c.UseSSL = ssl
return true, nil
}
func (c *LdapClient) Authenticate(realm string, username, password string) (bool, error) {
if c.Conn == nil {
return false, fmt.Errorf("no existing connection")
}
c.Realm = realm
c.BaseDN = fmt.Sprintf("dc=%s", strings.Join(strings.Split(realm, "."), ",dc="))
if err := c.Conn.NTLMBind(realm, username, password); err == nil {
// if bind with NTLMBind(), there is nothing
// else to do, you are authenticated
return true, nil
}
switch password {
case "":
if err := c.Conn.UnauthenticatedBind(username); err != nil {
return false, err
}
default:
if err := c.Conn.Bind(username, password); err != nil {
return false, err
}
}
return true, nil
}
func (c *LdapClient) AuthenticateWithNTLMHash(realm string, username, hash string) (bool, error) {
if c.Conn == nil {
return false, fmt.Errorf("no existing connection")
}
c.Realm = realm
c.BaseDN = fmt.Sprintf("dc=%s", strings.Join(strings.Split(realm, "."), ",dc="))
if err := c.Conn.NTLMBindWithHash(realm, username, hash); err != nil {
return false, err
}
return true, nil
}
// LDAP makes you search using an OID
// http://oid-info.com/get/1.2.840.113556.1.4.803
//
// The one for the userAccountControl in MS Active Directory is
// 1.2.840.113556.1.4.803 (LDAP_MATCHING_RULE_BIT_AND)
//
// We can look at the enabled flags using a query like (!(userAccountControl:1.2.840.113556.1.4.803:=2))
//
// https://learn.microsoft.com/en-us/troubleshoot/windows-server/identity/useraccountcontrol-manipulate-account-properties
const (
FilterIsPerson = "(objectCategory=person)"
FilterIsGroup = "(objectCategory=group)"
FilterIsComputer = "(objectCategory=computer)"
FilterIsAdmin = "(adminCount=1)"
FilterLogonScript = "(userAccountControl:1.2.840.113556.1.4.803:=1)" // The logon script will be run.
FilterAccountDisabled = "(userAccountControl:1.2.840.113556.1.4.803:=2)" // The user account is disabled.
FilterAccountEnabled = "(!(userAccountControl:1.2.840.113556.1.4.803:=2))" // The user account is enabled.
FilterHomedirRequired = "(userAccountControl:1.2.840.113556.1.4.803:=8)" // The home folder is required.
FilterLockout = "(userAccountControl:1.2.840.113556.1.4.803:=16)" // The user is locked out.
FilterPasswordNotRequired = "(userAccountControl:1.2.840.113556.1.4.803:=32)" // No password is required.
FilterPasswordCantChange = "(userAccountControl:1.2.840.113556.1.4.803:=64)" // The user can't change the password.
FilterCanSendEncryptedPassword = "(userAccountControl:1.2.840.113556.1.4.803:=128)" // The user can send an encrypted password.
FilterIsDuplicateAccount = "(userAccountControl:1.2.840.113556.1.4.803:=256)" // It's an account for users whose primary account is in another domain.
FilterIsNormalAccount = "(userAccountControl:1.2.840.113556.1.4.803:=512)" // It's a default account type that represents a typical user.
FilterInterdomainTrustAccount = "(userAccountControl:1.2.840.113556.1.4.803:=2048)" // It's a permit to trust an account for a system domain that trusts other domains.
FilterWorkstationTrustAccount = "(userAccountControl:1.2.840.113556.1.4.803:=4096)" // It's a computer account for a computer that is running old Windows builds.
FilterServerTrustAccount = "(userAccountControl:1.2.840.113556.1.4.803:=8192)" // It's a computer account for a domain controller that is a member of this domain.
FilterDontExpirePassword = "(userAccountControl:1.2.840.113556.1.4.803:=65536)" // Represents the password, which should never expire on the account.
FilterMnsLogonAccount = "(userAccountControl:1.2.840.113556.1.4.803:=131072)" // It's an MNS logon account.
FilterSmartCardRequired = "(userAccountControl:1.2.840.113556.1.4.803:=262144)" // When this flag is set, it forces the user to log on by using a smart card.
FilterTrustedForDelegation = "(userAccountControl:1.2.840.113556.1.4.803:=524288)" // When this flag is set, the service account (the user or computer account) under which a service runs is trusted for Kerberos delegation.
FilterNotDelegated = "(userAccountControl:1.2.840.113556.1.4.803:=1048576)" // When this flag is set, the security context of the user isn't delegated to a service even if the service account is set as trusted for Kerberos delegation.
FilterUseDesKeyOnly = "(userAccountControl:1.2.840.113556.1.4.803:=2097152)" // Restrict this principal to use only Data Encryption Standard (DES) encryption types for keys.
FilterDontRequirePreauth = "(userAccountControl:1.2.840.113556.1.4.803:=4194304)" // This account doesn't require Kerberos pre-authentication for logging on.
FilterPasswordExpired = "(userAccountControl:1.2.840.113556.1.4.803:=8388608)" // The user's password has expired.
FilterTrustedToAuthForDelegation = "(userAccountControl:1.2.840.113556.1.4.803:=16777216)" // The account is enabled for delegation.
FilterPartialSecretsAccount = "(userAccountControl:1.2.840.113556.1.4.803:=67108864)" // The account is a read-only domain controller (RODC).
)
func JoinFilters(filters ...string) string {
var builder strings.Builder
builder.WriteString("(&")
for _, s := range filters {
builder.WriteString(s)
}
builder.WriteString(")")
return builder.String()
}
func NegativeFilter(filter string) string {
return fmt.Sprintf("(!%s)", filter)
}
// Search is a method that uses the already Connect()'ed client to query the LDAP
// server, works for openldap and for Microsoft's Active Directory Ldap
//
// accepts whatever filter and returns a list of maps having provided attributes
// as keys and associated values mirroring the ones returned by ldap
func (c *LdapClient) Search(filter string, attributes ...string) ([]map[string][]string, error) {
res, err := c.Conn.Search(ldap.NewSearchRequest(
c.BaseDN, ldap.ScopeWholeSubtree, ldap.NeverDerefAliases,
0, 0, false, filter, attributes, nil,
))
if err != nil {
return nil, err
}
if len(res.Entries) == 0 {
return nil, fmt.Errorf("no result found in search")
}
var out []map[string][]string
for _, r := range res.Entries {
app := make(map[string][]string)
empty := true
for _, a := range attributes {
v := r.GetAttributeValues(a)
if len(v) > 0 {
app[a] = v
empty = false
}
}
if !empty {
out = append(out, app)
}
}
return out, nil
}
// Metadata is the metadata for ldap server.
type Metadata struct {
BaseDN string
Domain string
DefaultNamingContext string
DomainFunctionality string
ForestFunctionality string
DomainControllerFunctionality string
DnsHostName string
}
// CollectLdapMetadata collects metadata from ldap server.
func (c *LdapClient) CollectMetadata(domain string, controller string) (Metadata, error) {
if c.Conn == nil {
return Metadata{}, fmt.Errorf("no existing connection")
}
defer c.Conn.Close()
var metadata Metadata
metadata.BaseDN = c.BaseDN
metadata.Domain = c.Realm
srMetadata := ldap.NewSearchRequest(
"",
ldap.ScopeBaseObject,
ldap.NeverDerefAliases,
0, 0, false,
"(objectClass=*)",
[]string{
"defaultNamingContext",
"domainFunctionality",
"forestFunctionality",
"domainControllerFunctionality",
"dnsHostName",
},
nil)
resMetadata, err := c.Conn.Search(srMetadata)
if err != nil {
return metadata, err
}
for _, entry := range resMetadata.Entries {
for _, attr := range entry.Attributes {
value := entry.GetAttributeValue(attr.Name)
switch attr.Name {
case "defaultNamingContext":
metadata.DefaultNamingContext = value
case "domainFunctionality":
metadata.DomainFunctionality = value
case "forestFunctionality":
metadata.ForestFunctionality = value
case "domainControllerFunctionality":
metadata.DomainControllerFunctionality = value
case "dnsHostName":
metadata.DnsHostName = value
}
}
}
return metadata, nil
}
// KerberoastableUser contains the important fields of the Active Directory
// kerberoastable user
type KerberoastableUser struct {
SAMAccountName string
ServicePrincipalName string
PWDLastSet string
MemberOf string
UserAccountControl string
LastLogon string
}
// GetKerberoastableUsers collects all "person" users that have an SPN
// associated with them. The LDAP filter is built with the same logic as
// "GetUserSPNs.py", the well-known impacket example by Forta.
// https://github.com/fortra/impacket/blob/master/examples/GetUserSPNs.py#L297
//
// Returns a list of KerberoastableUser, if an error occurs, returns an empty
// slice and the raised error
func (c *LdapClient) GetKerberoastableUsers(domain, controller string, username, password string) ([]KerberoastableUser, error) {
sr := ldap.NewSearchRequest(
c.BaseDN,
ldap.ScopeWholeSubtree,
ldap.NeverDerefAliases,
0, 0, false,
// (&(is_user) (!(account_is_disabled)) (has_SPN))
"(&(objectCategory=person)(!(userAccountControl:1.2.840.113556.1.4.803:=2))(servicePrincipalName=*))",
[]string{
"SAMAccountName",
"ServicePrincipalName",
"pwdLastSet",
"MemberOf",
"userAccountControl",
"lastLogon",
},
nil,
)
res, err := c.Conn.Search(sr)
if err != nil {
return nil, err
}
if len(res.Entries) == 0 {
return nil, fmt.Errorf("no kerberoastable user found")
}
var ku []KerberoastableUser
for _, usr := range res.Entries {
ku = append(ku, KerberoastableUser{
SAMAccountName: usr.GetAttributeValue("sAMAccountName"),
ServicePrincipalName: usr.GetAttributeValue("servicePrincipalName"),
PWDLastSet: usr.GetAttributeValue("pwdLastSet"),
MemberOf: usr.GetAttributeValue("MemberOf"),
UserAccountControl: usr.GetAttributeValue("userAccountControl"),
LastLogon: usr.GetAttributeValue("lastLogon"),
})
}
return ku, nil
}