ContainerImage.Pinniped/internal/controller/supervisorconfig/oidcupstreamwatcher/oidc_upstream_watcher.go
2022-08-26 11:35:35 -07:00

515 lines
19 KiB
Go

// Copyright 2020-2022 the Pinniped contributors. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0
// Package oidcupstreamwatcher implements a controller which watches OIDCIdentityProviders.
package oidcupstreamwatcher
import (
"context"
"crypto/x509"
"encoding/base64"
"fmt"
"net/http"
"net/url"
"strings"
"time"
coreosoidc "github.com/coreos/go-oidc/v3/oidc"
"github.com/go-logr/logr"
"golang.org/x/oauth2"
corev1 "k8s.io/api/core/v1"
"k8s.io/apimachinery/pkg/api/equality"
metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
"k8s.io/apimachinery/pkg/labels"
"k8s.io/apimachinery/pkg/util/cache"
"k8s.io/apimachinery/pkg/util/sets"
corev1informers "k8s.io/client-go/informers/core/v1"
"go.pinniped.dev/generated/latest/apis/supervisor/idp/v1alpha1"
oidcapi "go.pinniped.dev/generated/latest/apis/supervisor/oidc"
pinnipedclientset "go.pinniped.dev/generated/latest/client/supervisor/clientset/versioned"
idpinformers "go.pinniped.dev/generated/latest/client/supervisor/informers/externalversions/idp/v1alpha1"
"go.pinniped.dev/internal/constable"
pinnipedcontroller "go.pinniped.dev/internal/controller"
"go.pinniped.dev/internal/controller/conditionsutil"
"go.pinniped.dev/internal/controller/supervisorconfig/upstreamwatchers"
"go.pinniped.dev/internal/controllerlib"
"go.pinniped.dev/internal/net/phttp"
"go.pinniped.dev/internal/oidc/provider"
"go.pinniped.dev/internal/plog"
"go.pinniped.dev/internal/upstreamoidc"
)
const (
// Setup for the name of our controller in logs.
oidcControllerName = "oidc-upstream-observer"
// Constants related to the client credentials Secret.
oidcClientSecretType corev1.SecretType = "secrets.pinniped.dev/oidc-client"
clientIDDataKey = "clientID"
clientSecretDataKey = "clientSecret"
// Constants related to the OIDC provider discovery cache. These do not affect the cache of JWKS.
oidcValidatorCacheTTL = 15 * time.Minute
// Constants related to conditions.
typeClientCredentialsValid = "ClientCredentialsValid" //nolint:gosec // this is not a credential
typeAdditionalAuthorizeParametersValid = "AdditionalAuthorizeParametersValid"
typeOIDCDiscoverySucceeded = "OIDCDiscoverySucceeded"
reasonUnreachable = "Unreachable"
reasonInvalidResponse = "InvalidResponse"
reasonDisallowedParameterName = "DisallowedParameterName"
allParamNamesAllowedMsg = "additionalAuthorizeParameters parameter names are allowed"
// Errors that are generated by our reconcile process.
errOIDCFailureStatus = constable.Error("OIDCIdentityProvider has a failing condition")
)
var (
disallowedAdditionalAuthorizeParameters = map[string]bool{ //nolint:gochecknoglobals
// Reject these AdditionalAuthorizeParameters to avoid allowing the user's config to overwrite the parameters
// that are always used by Pinniped in authcode authorization requests. The OIDC library used would otherwise
// happily treat the user's config as an override. Users can already set the "client_id" and "scope" params
// using other settings, and the others never make sense to override. This map should be treated as read-only
// since it is a global variable.
"response_type": true,
"scope": true,
"client_id": true,
"state": true,
"nonce": true,
"code_challenge": true,
"code_challenge_method": true,
"redirect_uri": true,
// Reject "hd" for now because it is not safe to use with Google's OIDC provider until Pinniped also
// performs the corresponding validation on the ID token.
"hd": true,
}
)
// UpstreamOIDCIdentityProviderICache is a thread safe cache that holds a list of validated upstream OIDC IDP configurations.
type UpstreamOIDCIdentityProviderICache interface {
SetOIDCIdentityProviders([]provider.UpstreamOIDCIdentityProviderI)
}
// lruValidatorCache caches the *oidc.Provider associated with a particular issuer/TLS configuration.
type lruValidatorCache struct{ cache *cache.Expiring }
type lruValidatorCacheEntry struct {
provider *coreosoidc.Provider
client *http.Client
}
func (c *lruValidatorCache) getProvider(spec *v1alpha1.OIDCIdentityProviderSpec) (*coreosoidc.Provider, *http.Client) {
if result, ok := c.cache.Get(c.cacheKey(spec)); ok {
entry := result.(*lruValidatorCacheEntry)
return entry.provider, entry.client
}
return nil, nil
}
func (c *lruValidatorCache) putProvider(spec *v1alpha1.OIDCIdentityProviderSpec, provider *coreosoidc.Provider, client *http.Client) {
c.cache.Set(c.cacheKey(spec), &lruValidatorCacheEntry{provider: provider, client: client}, oidcValidatorCacheTTL)
}
func (c *lruValidatorCache) cacheKey(spec *v1alpha1.OIDCIdentityProviderSpec) interface{} {
var key struct{ issuer, caBundle string }
key.issuer = spec.Issuer
if spec.TLS != nil {
key.caBundle = spec.TLS.CertificateAuthorityData
}
return key
}
type oidcWatcherController struct {
cache UpstreamOIDCIdentityProviderICache
log logr.Logger
client pinnipedclientset.Interface
oidcIdentityProviderInformer idpinformers.OIDCIdentityProviderInformer
secretInformer corev1informers.SecretInformer
validatorCache interface {
getProvider(*v1alpha1.OIDCIdentityProviderSpec) (*coreosoidc.Provider, *http.Client)
putProvider(*v1alpha1.OIDCIdentityProviderSpec, *coreosoidc.Provider, *http.Client)
}
}
// New instantiates a new controllerlib.Controller which will populate the provided UpstreamOIDCIdentityProviderICache.
func New(
idpCache UpstreamOIDCIdentityProviderICache,
client pinnipedclientset.Interface,
oidcIdentityProviderInformer idpinformers.OIDCIdentityProviderInformer,
secretInformer corev1informers.SecretInformer,
log logr.Logger,
withInformer pinnipedcontroller.WithInformerOptionFunc,
) controllerlib.Controller {
c := oidcWatcherController{
cache: idpCache,
log: log.WithName(oidcControllerName),
client: client,
oidcIdentityProviderInformer: oidcIdentityProviderInformer,
secretInformer: secretInformer,
validatorCache: &lruValidatorCache{cache: cache.NewExpiring()},
}
return controllerlib.New(
controllerlib.Config{Name: oidcControllerName, Syncer: &c},
withInformer(
oidcIdentityProviderInformer,
pinnipedcontroller.MatchAnythingFilter(pinnipedcontroller.SingletonQueue()),
controllerlib.InformerOption{},
),
withInformer(
secretInformer,
pinnipedcontroller.MatchAnySecretOfTypeFilter(oidcClientSecretType, pinnipedcontroller.SingletonQueue()),
controllerlib.InformerOption{},
),
)
}
// Sync implements controllerlib.Syncer.
func (c *oidcWatcherController) Sync(ctx controllerlib.Context) error {
actualUpstreams, err := c.oidcIdentityProviderInformer.Lister().List(labels.Everything())
if err != nil {
return fmt.Errorf("failed to list OIDCIdentityProviders: %w", err)
}
requeue := false
validatedUpstreams := make([]provider.UpstreamOIDCIdentityProviderI, 0, len(actualUpstreams))
for _, upstream := range actualUpstreams {
valid := c.validateUpstream(ctx, upstream)
if valid == nil {
requeue = true
} else {
validatedUpstreams = append(validatedUpstreams, provider.UpstreamOIDCIdentityProviderI(valid))
}
}
c.cache.SetOIDCIdentityProviders(validatedUpstreams)
if requeue {
return controllerlib.ErrSyntheticRequeue
}
return nil
}
// validateUpstream validates the provided v1alpha1.OIDCIdentityProvider and returns the validated configuration as a
// provider.UpstreamOIDCIdentityProvider. As a side effect, it also updates the status of the v1alpha1.OIDCIdentityProvider.
func (c *oidcWatcherController) validateUpstream(ctx controllerlib.Context, upstream *v1alpha1.OIDCIdentityProvider) *upstreamoidc.ProviderConfig {
authorizationConfig := upstream.Spec.AuthorizationConfig
additionalAuthcodeAuthorizeParameters := map[string]string{}
var rejectedAuthcodeAuthorizeParameters []string
for _, p := range authorizationConfig.AdditionalAuthorizeParameters {
if disallowedAdditionalAuthorizeParameters[p.Name] {
rejectedAuthcodeAuthorizeParameters = append(rejectedAuthcodeAuthorizeParameters, p.Name)
} else {
additionalAuthcodeAuthorizeParameters[p.Name] = p.Value
}
}
result := upstreamoidc.ProviderConfig{
Name: upstream.Name,
Config: &oauth2.Config{
Scopes: computeScopes(authorizationConfig.AdditionalScopes),
},
UsernameClaim: upstream.Spec.Claims.Username,
GroupsClaim: upstream.Spec.Claims.Groups,
AllowPasswordGrant: authorizationConfig.AllowPasswordGrant,
AdditionalAuthcodeParams: additionalAuthcodeAuthorizeParameters,
ResourceUID: upstream.UID,
}
conditions := []*v1alpha1.Condition{
c.validateSecret(upstream, &result),
c.validateIssuer(ctx.Context, upstream, &result),
}
if len(rejectedAuthcodeAuthorizeParameters) > 0 {
conditions = append(conditions, &v1alpha1.Condition{
Type: typeAdditionalAuthorizeParametersValid,
Status: v1alpha1.ConditionFalse,
Reason: reasonDisallowedParameterName,
Message: fmt.Sprintf("the following additionalAuthorizeParameters are not allowed: %s",
strings.Join(rejectedAuthcodeAuthorizeParameters, ",")),
})
} else {
conditions = append(conditions, &v1alpha1.Condition{
Type: typeAdditionalAuthorizeParametersValid,
Status: v1alpha1.ConditionTrue,
Reason: upstreamwatchers.ReasonSuccess,
Message: allParamNamesAllowedMsg,
})
}
c.updateStatus(ctx.Context, upstream, conditions)
valid := true
log := c.log.WithValues("namespace", upstream.Namespace, "name", upstream.Name)
for _, condition := range conditions {
if condition.Status == v1alpha1.ConditionFalse {
valid = false
log.WithValues(
"type", condition.Type,
"reason", condition.Reason,
"message", condition.Message,
).Error(errOIDCFailureStatus, "found failing condition")
}
}
if valid {
return &result
}
return nil
}
// validateSecret validates the .spec.client.secretName field and returns the appropriate ClientCredentialsValid condition.
func (c *oidcWatcherController) validateSecret(upstream *v1alpha1.OIDCIdentityProvider, result *upstreamoidc.ProviderConfig) *v1alpha1.Condition {
secretName := upstream.Spec.Client.SecretName
// Fetch the Secret from informer cache.
secret, err := c.secretInformer.Lister().Secrets(upstream.Namespace).Get(secretName)
if err != nil {
return &v1alpha1.Condition{
Type: typeClientCredentialsValid,
Status: v1alpha1.ConditionFalse,
Reason: upstreamwatchers.ReasonNotFound,
Message: err.Error(),
}
}
// Validate the secret .type field.
if secret.Type != oidcClientSecretType {
return &v1alpha1.Condition{
Type: typeClientCredentialsValid,
Status: v1alpha1.ConditionFalse,
Reason: upstreamwatchers.ReasonWrongType,
Message: fmt.Sprintf("referenced Secret %q has wrong type %q (should be %q)", secretName, secret.Type, oidcClientSecretType),
}
}
// Validate the secret .data field.
clientID := secret.Data[clientIDDataKey]
clientSecret := secret.Data[clientSecretDataKey]
if len(clientID) == 0 || len(clientSecret) == 0 {
return &v1alpha1.Condition{
Type: typeClientCredentialsValid,
Status: v1alpha1.ConditionFalse,
Reason: upstreamwatchers.ReasonMissingKeys,
Message: fmt.Sprintf("referenced Secret %q is missing required keys %q", secretName, []string{clientIDDataKey, clientSecretDataKey}),
}
}
// If everything is valid, update the result and set the condition to true.
result.Config.ClientID = string(clientID)
result.Config.ClientSecret = string(clientSecret)
return &v1alpha1.Condition{
Type: typeClientCredentialsValid,
Status: v1alpha1.ConditionTrue,
Reason: upstreamwatchers.ReasonSuccess,
Message: "loaded client credentials",
}
}
// validateIssuer validates the .spec.issuer field, performs OIDC discovery, and returns the appropriate OIDCDiscoverySucceeded condition.
func (c *oidcWatcherController) validateIssuer(ctx context.Context, upstream *v1alpha1.OIDCIdentityProvider, result *upstreamoidc.ProviderConfig) *v1alpha1.Condition {
// Get the provider and HTTP Client from cache if possible.
discoveredProvider, httpClient := c.validatorCache.getProvider(&upstream.Spec)
// If the provider does not exist in the cache, do a fresh discovery lookup and save to the cache.
if discoveredProvider == nil {
var err error
httpClient, err = getClient(upstream)
if err != nil {
return &v1alpha1.Condition{
Type: typeOIDCDiscoverySucceeded,
Status: v1alpha1.ConditionFalse,
Reason: upstreamwatchers.ReasonInvalidTLSConfig,
Message: err.Error(),
}
}
_, issuerURLCondition := validateHTTPSURL(upstream.Spec.Issuer, "issuer", reasonUnreachable)
if issuerURLCondition != nil {
return issuerURLCondition
}
discoveredProvider, err = coreosoidc.NewProvider(coreosoidc.ClientContext(ctx, httpClient), upstream.Spec.Issuer)
if err != nil {
c.log.V(plog.KlogLevelTrace).WithValues(
"namespace", upstream.Namespace,
"name", upstream.Name,
"issuer", upstream.Spec.Issuer,
).Error(err, "failed to perform OIDC discovery")
return &v1alpha1.Condition{
Type: typeOIDCDiscoverySucceeded,
Status: v1alpha1.ConditionFalse,
Reason: reasonUnreachable,
Message: fmt.Sprintf("failed to perform OIDC discovery against %q:\n%s", upstream.Spec.Issuer, truncateMostLongErr(err)),
}
}
// Update the cache with the newly discovered value.
c.validatorCache.putProvider(&upstream.Spec, discoveredProvider, httpClient)
}
// Get the revocation endpoint, if there is one. Many providers do not offer a revocation endpoint.
var additionalDiscoveryClaims struct {
// "revocation_endpoint" is specified by https://datatracker.ietf.org/doc/html/rfc8414#section-2
RevocationEndpoint string `json:"revocation_endpoint"`
}
if err := discoveredProvider.Claims(&additionalDiscoveryClaims); err != nil {
// This shouldn't actually happen because the above call to NewProvider() would have already returned this error.
return &v1alpha1.Condition{
Type: typeOIDCDiscoverySucceeded,
Status: v1alpha1.ConditionFalse,
Reason: reasonInvalidResponse,
Message: fmt.Sprintf("failed to unmarshal OIDC discovery response from %q:\n%s", upstream.Spec.Issuer, truncateMostLongErr(err)),
}
}
if additionalDiscoveryClaims.RevocationEndpoint != "" {
// Found a revocation URL. Validate it.
revocationURL, revocationURLCondition := validateHTTPSURL(
additionalDiscoveryClaims.RevocationEndpoint,
"revocation endpoint",
reasonInvalidResponse,
)
if revocationURLCondition != nil {
return revocationURLCondition
}
// Remember the URL for later use.
result.RevocationURL = revocationURL
}
_, authorizeURLCondition := validateHTTPSURL(
discoveredProvider.Endpoint().AuthURL,
"authorization endpoint",
reasonInvalidResponse,
)
if authorizeURLCondition != nil {
return authorizeURLCondition
}
_, tokenURLCondition := validateHTTPSURL(
discoveredProvider.Endpoint().TokenURL,
"token endpoint",
reasonInvalidResponse,
)
if tokenURLCondition != nil {
return tokenURLCondition
}
// If everything is valid, update the result and set the condition to true.
result.Config.Endpoint = discoveredProvider.Endpoint()
result.Provider = discoveredProvider
result.Client = httpClient
return &v1alpha1.Condition{
Type: typeOIDCDiscoverySucceeded,
Status: v1alpha1.ConditionTrue,
Reason: upstreamwatchers.ReasonSuccess,
Message: "discovered issuer configuration",
}
}
func (c *oidcWatcherController) updateStatus(ctx context.Context, upstream *v1alpha1.OIDCIdentityProvider, conditions []*v1alpha1.Condition) {
log := c.log.WithValues("namespace", upstream.Namespace, "name", upstream.Name)
updated := upstream.DeepCopy()
hadErrorCondition := conditionsutil.MergeIDPConditions(conditions, upstream.Generation, &updated.Status.Conditions, log)
updated.Status.Phase = v1alpha1.PhaseReady
if hadErrorCondition {
updated.Status.Phase = v1alpha1.PhaseError
}
if equality.Semantic.DeepEqual(upstream, updated) {
return
}
_, err := c.client.
IDPV1alpha1().
OIDCIdentityProviders(upstream.Namespace).
UpdateStatus(ctx, updated, metav1.UpdateOptions{})
if err != nil {
log.Error(err, "failed to update status")
}
}
func getClient(upstream *v1alpha1.OIDCIdentityProvider) (*http.Client, error) {
if upstream.Spec.TLS == nil || upstream.Spec.TLS.CertificateAuthorityData == "" {
return defaultClientShortTimeout(nil), nil
}
bundle, err := base64.StdEncoding.DecodeString(upstream.Spec.TLS.CertificateAuthorityData)
if err != nil {
return nil, fmt.Errorf("spec.certificateAuthorityData is invalid: %w", err)
}
rootCAs := x509.NewCertPool()
if !rootCAs.AppendCertsFromPEM(bundle) {
return nil, fmt.Errorf("spec.certificateAuthorityData is invalid: %w", upstreamwatchers.ErrNoCertificates)
}
return defaultClientShortTimeout(rootCAs), nil
}
func defaultClientShortTimeout(rootCAs *x509.CertPool) *http.Client {
c := phttp.Default(rootCAs)
c.Timeout = time.Minute
return c
}
func computeScopes(additionalScopes []string) []string {
// If none are set then provide a reasonable default which only tries to use scopes defined in the OIDC spec.
if len(additionalScopes) == 0 {
return []string{oidcapi.ScopeOpenID, oidcapi.ScopeOfflineAccess, oidcapi.ScopeEmail, oidcapi.ScopeProfile}
}
// Otherwise, first compute the unique set of scopes, including "openid" (de-duplicate).
set := sets.NewString()
set.Insert(oidcapi.ScopeOpenID)
for _, s := range additionalScopes {
set.Insert(s)
}
// Return the set as a sorted list.
return set.List()
}
func truncateMostLongErr(err error) string {
const max = 300
msg := err.Error()
// always log oidc and x509 errors completely
if len(msg) <= max || strings.Contains(msg, "oidc:") || strings.Contains(msg, "x509:") {
return msg
}
return msg[:max] + fmt.Sprintf(" [truncated %d chars]", len(msg)-max)
}
func validateHTTPSURL(maybeHTTPSURL, endpointType, reason string) (*url.URL, *v1alpha1.Condition) {
parsedURL, err := url.Parse(maybeHTTPSURL)
if err != nil {
return nil, &v1alpha1.Condition{
Type: typeOIDCDiscoverySucceeded,
Status: v1alpha1.ConditionFalse,
Reason: reason,
Message: fmt.Sprintf("failed to parse %s URL: %v", endpointType, truncateMostLongErr(err)),
}
}
if parsedURL.Scheme != "https" {
return nil, &v1alpha1.Condition{
Type: typeOIDCDiscoverySucceeded,
Status: v1alpha1.ConditionFalse,
Reason: reason,
Message: fmt.Sprintf(`%s URL '%s' must have "https" scheme, not %q`, endpointType, maybeHTTPSURL, parsedURL.Scheme),
}
}
if len(parsedURL.Query()) != 0 || parsedURL.Fragment != "" {
return nil, &v1alpha1.Condition{
Type: typeOIDCDiscoverySucceeded,
Status: v1alpha1.ConditionFalse,
Reason: reason,
Message: fmt.Sprintf(`%s URL '%s' cannot contain query or fragment component`, endpointType, maybeHTTPSURL),
}
}
return parsedURL, nil
}