outposts: don't authenticate as service user for flows to set remote-ip

set outpost token as additional header and check that token (user) if they can override remote-ip

Signed-off-by: Jens Langhammer <jens.langhammer@beryju.org>

authentik/core/models.py

@@ -38,6 +38,7 @@ USER_ATTRIBUTE_DEBUG = "goauthentik.io/user/debug"
 USER_ATTRIBUTE_SA = "goauthentik.io/user/service-account"
 USER_ATTRIBUTE_SOURCES = "goauthentik.io/user/sources"
 USER_ATTRIBUTE_TOKEN_EXPIRING = "goauthentik.io/user/token-expires"  # nosec
+USER_ATTRIBUTE_CAN_OVERRIDE_IP = "goauthentik.io/user/override-ips"
 
 GRAVATAR_URL = "https://secure.gravatar.com"
 DEFAULT_AVATAR = static("dist/assets/images/user_default.png")

authentik/lib/utils/http.py

@@ -2,10 +2,12 @@
 from typing import Any, Optional
 
 from django.http import HttpRequest
+from structlog.stdlib import get_logger
 
 OUTPOST_REMOTE_IP_HEADER = "HTTP_X_AUTHENTIK_REMOTE_IP"
-USER_ATTRIBUTE_CAN_OVERRIDE_IP = "goauthentik.io/user/override-ips"
+OUTPOST_TOKEN_HEADER = "HTTP_X_AUTHENTIK_OUTPOST_TOKEN"  # nosec
 DEFAULT_IP = "255.255.255.255"
+LOGGER = get_logger()
 
 
 def _get_client_ip_from_meta(meta: dict[str, Any]) -> str:
@@ -27,13 +29,25 @@ def _get_outpost_override_ip(request: HttpRequest) -> Optional[str]:
     """Get the actual remote IP when set by an outpost. Only
     allowed when the request is authenticated, by a user with USER_ATTRIBUTE_CAN_OVERRIDE_IP set
     to outpost"""
-    if not hasattr(request, "user"):
+    from authentik.core.models import (
+        USER_ATTRIBUTE_CAN_OVERRIDE_IP,
+        Token,
+        TokenIntents,
+    )
+
+    if (
+        OUTPOST_REMOTE_IP_HEADER not in request.META
+        or OUTPOST_TOKEN_HEADER not in request.META
+    ):
         return None
-    if not request.user.is_authenticated:
+    tokens = Token.filter_not_expired(
+        key=request.META.get(OUTPOST_TOKEN_HEADER), intent=TokenIntents.INTENT_API
+    )
+    if not tokens.exists():
+        LOGGER.warning("Attempted remote-ip override without token")
         return None
-    if OUTPOST_REMOTE_IP_HEADER not in request.META:
-        return None
-    if request.user.group_attributes().get(USER_ATTRIBUTE_CAN_OVERRIDE_IP, False):
+    user = tokens.first().user
+    if user.group_attributes().get(USER_ATTRIBUTE_CAN_OVERRIDE_IP, False):
         return None
     return request.META[OUTPOST_REMOTE_IP_HEADER]
 

authentik/outposts/models.py

@@ -28,12 +28,18 @@ from structlog.stdlib import get_logger
 from urllib3.exceptions import HTTPError
 
 from authentik import ENV_GIT_HASH_KEY, __version__
-from authentik.core.models import USER_ATTRIBUTE_SA, Provider, Token, TokenIntents, User
+from authentik.core.models import (
+    USER_ATTRIBUTE_CAN_OVERRIDE_IP,
+    USER_ATTRIBUTE_SA,
+    Provider,
+    Token,
+    TokenIntents,
+    User,
+)
 from authentik.crypto.models import CertificateKeyPair
 from authentik.lib.config import CONFIG
 from authentik.lib.models import InheritanceForeignKey
 from authentik.lib.sentry import SentryIgnoredException
-from authentik.lib.utils.http import USER_ATTRIBUTE_CAN_OVERRIDE_IP
 from authentik.managed.models import ManagedModel
 from authentik.outposts.controllers.k8s.utils import get_namespace
 from authentik.outposts.docker_tls import DockerInlineTLS

internal/outpost/flow.go

@@ -4,10 +4,12 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"net"
 	"net/http"
 	"net/http/cookiejar"
 	"net/url"
 	"strconv"
+	"strings"
 
 	log "github.com/sirupsen/logrus"
 	"goauthentik.io/api"
@@ -24,6 +26,11 @@ const (
 	StageAccessDenied          = StageComponent("ak-stage-access-denied")
 )
 
+const (
+	HeaderAuthentikRemoteIP     = "X-authentik-remote-ip"
+	HeaderAuthentikOutpostToken = "X-authentik-outpost-token"
+)
+
 type FlowExecutor struct {
 	Params  url.Values
 	Answers map[StageComponent]string
@@ -31,6 +38,7 @@ type FlowExecutor struct {
 	api      *api.APIClient
 	flowSlug string
 	log      *log.Entry
+	token    string
 }
 
 func NewFlowExecutor(flowSlug string, refConfig *api.Configuration) *FlowExecutor {
@@ -56,6 +64,7 @@ func NewFlowExecutor(flowSlug string, refConfig *api.Configuration) *FlowExecuto
 		api:      apiClient,
 		flowSlug: flowSlug,
 		log:      l,
+		token:    strings.Split(refConfig.DefaultHeader["Authorization"], " ")[1],
 	}
 }
 
@@ -69,6 +78,16 @@ type ChallengeInt interface {
 	GetResponseErrors() map[string][]api.ErrorDetail
 }
 
+func (fe *FlowExecutor) DelegateClientIP(a net.Addr) {
+	host, _, err := net.SplitHostPort(a.String())
+	if err != nil {
+		fe.log.WithError(err).Warning("Failed to get remote IP")
+		return
+	}
+	fe.api.GetConfig().AddDefaultHeader(HeaderAuthentikRemoteIP, host)
+	fe.api.GetConfig().AddDefaultHeader(HeaderAuthentikOutpostToken, fe.token)
+}
+
 func (fe *FlowExecutor) CheckApplicationAccess(appSlug string) (bool, error) {
 	p, _, err := fe.api.CoreApi.CoreApplicationsCheckAccessRetrieve(context.Background(), appSlug).Execute()
 	if !p.Passing {

internal/outpost/ldap/instance_bind.go

@@ -34,14 +34,8 @@ func (pi *ProviderInstance) getUsername(dn string) (string, error) {
 }
 
 func (pi *ProviderInstance) Bind(username string, bindDN, bindPW string, conn net.Conn) (ldap.LDAPResultCode, error) {
-	host, _, err := net.SplitHostPort(conn.RemoteAddr().String())
-	if err != nil {
-		pi.log.WithError(err).Warning("Failed to get remote IP")
-		return ldap.LDAPResultOperationsError, nil
-	}
-
 	fe := outpost.NewFlowExecutor(pi.flowSlug, pi.s.ac.Client.GetConfig())
-	fe.ApiClient().GetConfig().AddDefaultHeader("X-authentik-remote-ip", host)
+	fe.DelegateClientIP(conn.RemoteAddr())
 	fe.Params.Add("goauthentik.io/outpost/ldap", "true")
 
 	fe.Answers[outpost.StageIdentification] = username