Livio Spring 3c99cf82f8
feat: federated logout for SAML IdPs (#9931)
# Which Problems Are Solved

Currently if a user signs in using an IdP, once they sign out of
Zitadel, the corresponding IdP session is not terminated. This can be
the desired behavior. In some cases, e.g. when using a shared computer
it results in a potential security risk, since a follower user might be
able to sign in as the previous using the still open IdP session.

# How the Problems Are Solved

- Admins can enabled a federated logout option on SAML IdPs through the
Admin and Management APIs.
- During the termination of a login V1 session using OIDC end_session
endpoint, Zitadel will check if an IdP was used to authenticate that
session.
- In case there was a SAML IdP used with Federated Logout enabled, it
will intercept the logout process, store the information into the shared
cache and redirect to the federated logout endpoint in the V1 login.
- The V1 login federated logout endpoint checks every request on an
existing cache entry. On success it will create a SAML logout request
for the used IdP and either redirect or POST to the configured SLO
endpoint. The cache entry is updated with a `redirected` state.
- A SLO endpoint is added to the `/idp` handlers, which will handle the
SAML logout responses. At the moment it will check again for an existing
federated logout entry (with state `redirected`) in the cache. On
success, the user is redirected to the initially provided
`post_logout_redirect_uri` from the end_session request.

# Additional Changes

None

# Additional Context

- This PR merges the https://github.com/zitadel/zitadel/pull/9841 and
https://github.com/zitadel/zitadel/pull/9854 to main, additionally
updating the docs on Entra ID SAML.
- closes #9228
- backport to 3.x

---------

Co-authored-by: Silvan <27845747+adlerhurst@users.noreply.github.com>
Co-authored-by: Zach Hirschtritt <zachary.hirschtritt@klaviyo.com>
(cherry picked from commit 2cf3ef4de4ef993367daec6ff3974bdbdf70d2f3)
2025-05-23 14:59:34 +02:00

266 lines
9.9 KiB
Go

package oidc
import (
"context"
"fmt"
"log/slog"
"net/http"
"time"
"github.com/zitadel/oidc/v3/pkg/oidc"
"github.com/zitadel/oidc/v3/pkg/op"
"github.com/zitadel/zitadel/internal/api/assets"
http_utils "github.com/zitadel/zitadel/internal/api/http"
"github.com/zitadel/zitadel/internal/api/http/middleware"
"github.com/zitadel/zitadel/internal/api/ui/login"
"github.com/zitadel/zitadel/internal/auth/repository"
"github.com/zitadel/zitadel/internal/cache"
"github.com/zitadel/zitadel/internal/command"
"github.com/zitadel/zitadel/internal/crypto"
"github.com/zitadel/zitadel/internal/database"
"github.com/zitadel/zitadel/internal/domain/federatedlogout"
"github.com/zitadel/zitadel/internal/eventstore"
"github.com/zitadel/zitadel/internal/eventstore/handler/crdb"
"github.com/zitadel/zitadel/internal/query"
"github.com/zitadel/zitadel/internal/telemetry/metrics"
"github.com/zitadel/zitadel/internal/zerrors"
)
type Config struct {
CodeMethodS256 bool
AuthMethodPost bool
AuthMethodPrivateKeyJWT bool
GrantTypeRefreshToken bool
RequestObjectSupported bool
DefaultAccessTokenLifetime time.Duration
DefaultIdTokenLifetime time.Duration
DefaultRefreshTokenIdleExpiration time.Duration
DefaultRefreshTokenExpiration time.Duration
JWKSCacheControlMaxAge time.Duration
CustomEndpoints *EndpointConfig
DeviceAuth *DeviceAuthorizationConfig
DefaultLoginURLV2 string
DefaultLogoutURLV2 string
PublicKeyCacheMaxAge time.Duration
DefaultBackChannelLogoutLifetime time.Duration
}
type EndpointConfig struct {
Auth *Endpoint
Token *Endpoint
Introspection *Endpoint
Userinfo *Endpoint
Revocation *Endpoint
EndSession *Endpoint
Keys *Endpoint
DeviceAuth *Endpoint
}
type Endpoint struct {
Path string
URL string
}
type OPStorage struct {
repo repository.Repository
command *command.Commands
query *query.Queries
eventstore *eventstore.Eventstore
defaultLoginURL string
defaultLoginURLV2 string
defaultLogoutURLV2 string
defaultAccessTokenLifetime time.Duration
defaultIdTokenLifetime time.Duration
defaultRefreshTokenIdleExpiration time.Duration
defaultRefreshTokenExpiration time.Duration
encAlg crypto.EncryptionAlgorithm
locker crdb.Locker
assetAPIPrefix func(ctx context.Context) string
contextToIssuer func(context.Context) string
federateLogoutCache cache.Cache[federatedlogout.Index, string, *federatedlogout.FederatedLogout]
}
// Provider is used to overload certain [op.Provider] methods
type Provider struct {
*op.Provider
accessTokenKeySet oidc.KeySet
idTokenHintKeySet oidc.KeySet
}
// IDTokenHintVerifier configures a Verifier and supported signing algorithms based on the Web Key feature in the context.
func (o *Provider) IDTokenHintVerifier(ctx context.Context) *op.IDTokenHintVerifier {
return op.NewIDTokenHintVerifier(op.IssuerFromContext(ctx), o.idTokenHintKeySet, op.WithSupportedIDTokenHintSigningAlgorithms(
supportedSigningAlgs(ctx)...,
))
}
// AccessTokenVerifier configures a Verifier and supported signing algorithms based on the Web Key feature in the context.
func (o *Provider) AccessTokenVerifier(ctx context.Context) *op.AccessTokenVerifier {
return op.NewAccessTokenVerifier(op.IssuerFromContext(ctx), o.accessTokenKeySet, op.WithSupportedAccessTokenSigningAlgorithms(
supportedSigningAlgs(ctx)...,
))
}
func NewServer(
ctx context.Context,
config Config,
defaultLogoutRedirectURI string,
externalSecure bool,
command *command.Commands,
query *query.Queries,
repo repository.Repository,
encryptionAlg crypto.EncryptionAlgorithm,
cryptoKey []byte,
es *eventstore.Eventstore,
projections *database.DB,
userAgentCookie, instanceHandler func(http.Handler) http.Handler,
accessHandler *middleware.AccessInterceptor,
fallbackLogger *slog.Logger,
hashConfig crypto.HashConfig,
federatedLogoutCache cache.Cache[federatedlogout.Index, string, *federatedlogout.FederatedLogout],
) (*Server, error) {
opConfig, err := createOPConfig(config, defaultLogoutRedirectURI, cryptoKey)
if err != nil {
return nil, zerrors.ThrowInternal(err, "OIDC-EGrqd", "cannot create op config: %w")
}
storage := newStorage(config, command, query, repo, encryptionAlg, es, projections, ContextToIssuer, federatedLogoutCache)
keyCache := newPublicKeyCache(ctx, config.PublicKeyCacheMaxAge, queryKeyFunc(query))
accessTokenKeySet := newOidcKeySet(keyCache, withKeyExpiryCheck(true))
idTokenHintKeySet := newOidcKeySet(keyCache)
var options []op.Option
if !externalSecure {
options = append(options, op.WithAllowInsecure())
}
provider, err := op.NewProvider(
opConfig,
storage,
IssuerFromContext,
options...,
)
if err != nil {
return nil, zerrors.ThrowInternal(err, "OIDC-DAtg3", "cannot create provider")
}
hasher, err := hashConfig.NewHasher()
if err != nil {
return nil, zerrors.ThrowInternal(err, "OIDC-Aij4e", "cannot create secret hasher")
}
server := &Server{
LegacyServer: op.NewLegacyServer(&Provider{
Provider: provider,
accessTokenKeySet: accessTokenKeySet,
idTokenHintKeySet: idTokenHintKeySet,
}, endpoints(config.CustomEndpoints)),
repo: repo,
query: query,
command: command,
accessTokenKeySet: accessTokenKeySet,
idTokenHintKeySet: idTokenHintKeySet,
defaultLoginURL: fmt.Sprintf("%s%s?%s=", login.HandlerPrefix, login.EndpointLogin, login.QueryAuthRequestID),
defaultLoginURLV2: config.DefaultLoginURLV2,
defaultLogoutURLV2: config.DefaultLogoutURLV2,
defaultAccessTokenLifetime: config.DefaultAccessTokenLifetime,
defaultIdTokenLifetime: config.DefaultIdTokenLifetime,
jwksCacheControlMaxAge: config.JWKSCacheControlMaxAge,
fallbackLogger: fallbackLogger,
hasher: hasher,
encAlg: encryptionAlg,
opCrypto: op.NewAESCrypto(opConfig.CryptoKey),
assetAPIPrefix: assets.AssetAPI(),
}
metricTypes := []metrics.MetricType{metrics.MetricTypeRequestCount, metrics.MetricTypeStatusCode, metrics.MetricTypeTotalCount}
server.Handler = op.RegisterLegacyServer(server,
server.authorizeCallbackHandler,
op.WithFallbackLogger(fallbackLogger),
op.WithHTTPMiddleware(
middleware.MetricsHandler(metricTypes),
middleware.TelemetryHandler(),
middleware.NoCacheInterceptor().Handler,
instanceHandler,
userAgentCookie,
http_utils.CopyHeadersToContext,
accessHandler.HandleWithPublicAuthPathPrefixes(publicAuthPathPrefixes(config.CustomEndpoints)),
middleware.ActivityHandler,
))
return server, nil
}
func ContextToIssuer(ctx context.Context) string {
return http_utils.DomainContext(ctx).Origin()
}
func IssuerFromContext(_ bool) (op.IssuerFromRequest, error) {
return func(r *http.Request) string {
return ContextToIssuer(r.Context())
}, nil
}
func publicAuthPathPrefixes(endpoints *EndpointConfig) []string {
authURL := op.DefaultEndpoints.Authorization.Relative()
keysURL := op.DefaultEndpoints.JwksURI.Relative()
if endpoints == nil {
return []string{oidc.DiscoveryEndpoint, authURL, keysURL}
}
if endpoints.Auth != nil && endpoints.Auth.Path != "" {
authURL = endpoints.Auth.Path
}
if endpoints.Keys != nil && endpoints.Keys.Path != "" {
keysURL = endpoints.Keys.Path
}
return []string{oidc.DiscoveryEndpoint, authURL, keysURL}
}
func createOPConfig(config Config, defaultLogoutRedirectURI string, cryptoKey []byte) (*op.Config, error) {
opConfig := &op.Config{
DefaultLogoutRedirectURI: defaultLogoutRedirectURI,
CodeMethodS256: config.CodeMethodS256,
AuthMethodPost: config.AuthMethodPost,
AuthMethodPrivateKeyJWT: config.AuthMethodPrivateKeyJWT,
GrantTypeRefreshToken: config.GrantTypeRefreshToken,
RequestObjectSupported: config.RequestObjectSupported,
DeviceAuthorization: config.DeviceAuth.toOPConfig(),
}
if cryptoLength := len(cryptoKey); cryptoLength != 32 {
return nil, zerrors.ThrowInternalf(nil, "OIDC-D43gf", "crypto key must be 32 bytes, but is %d", cryptoLength)
}
copy(opConfig.CryptoKey[:], cryptoKey)
return opConfig, nil
}
func newStorage(
config Config,
command *command.Commands,
query *query.Queries,
repo repository.Repository,
encAlg crypto.EncryptionAlgorithm,
es *eventstore.Eventstore,
db *database.DB,
contextToIssuer func(context.Context) string,
federateLogoutCache cache.Cache[federatedlogout.Index, string, *federatedlogout.FederatedLogout],
) *OPStorage {
return &OPStorage{
repo: repo,
command: command,
query: query,
eventstore: es,
defaultLoginURL: fmt.Sprintf("%s%s?%s=", login.HandlerPrefix, login.EndpointLogin, login.QueryAuthRequestID),
defaultLoginURLV2: config.DefaultLoginURLV2,
defaultLogoutURLV2: config.DefaultLogoutURLV2,
defaultAccessTokenLifetime: config.DefaultAccessTokenLifetime,
defaultIdTokenLifetime: config.DefaultIdTokenLifetime,
defaultRefreshTokenIdleExpiration: config.DefaultRefreshTokenIdleExpiration,
defaultRefreshTokenExpiration: config.DefaultRefreshTokenExpiration,
encAlg: encAlg,
locker: crdb.NewLocker(db.DB, locksTable, signingKey),
assetAPIPrefix: assets.AssetAPI(),
contextToIssuer: contextToIssuer,
federateLogoutCache: federateLogoutCache,
}
}
func (o *OPStorage) Health(ctx context.Context) error {
return o.repo.Health(ctx)
}