ContainerImage.Pinniped/internal/controller/supervisorconfig/jwks_writer.go
Ryan Richard c6c2c525a6 Upgrade the linter and fix all new linter warnings
Also fix some tests that were broken by bumping golang and dependencies
in the previous commits.

Note that in addition to changes made to satisfy the linter which do not
impact the behavior of the code, this commit also adds ReadHeaderTimeout
to all usages of http.Server to satisfy the linter (and because it
seemed like a good suggestion).
2022-08-24 14:45:55 -07:00

369 lines
12 KiB
Go

// Copyright 2020-2022 the Pinniped contributors. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0
package supervisorconfig
import (
"context"
"crypto/ecdsa"
"crypto/elliptic"
"crypto/rand"
"encoding/json"
"fmt"
"io"
"gopkg.in/square/go-jose.v2"
corev1 "k8s.io/api/core/v1"
k8serrors "k8s.io/apimachinery/pkg/api/errors"
metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
"k8s.io/apimachinery/pkg/runtime/schema"
corev1informers "k8s.io/client-go/informers/core/v1"
"k8s.io/client-go/kubernetes"
"k8s.io/client-go/util/retry"
"k8s.io/klog/v2"
configv1alpha1 "go.pinniped.dev/generated/latest/apis/supervisor/config/v1alpha1"
pinnipedclientset "go.pinniped.dev/generated/latest/client/supervisor/clientset/versioned"
configinformers "go.pinniped.dev/generated/latest/client/supervisor/informers/externalversions/config/v1alpha1"
pinnipedcontroller "go.pinniped.dev/internal/controller"
"go.pinniped.dev/internal/controller/supervisorconfig/generator"
"go.pinniped.dev/internal/controllerlib"
"go.pinniped.dev/internal/plog"
)
// These constants are the keys in a FederationDomain's Secret's Data map.
const (
// activeJWKKey points to the current private key used for signing tokens.
//
// Note! The value for this key will contain private key material!
activeJWKKey = "activeJWK"
// jwksKey points to the current JWKS used to verify tokens.
//
// Note! The value for this key will contain only public key material!
jwksKey = "jwks"
jwksSecretTypeValue corev1.SecretType = "secrets.pinniped.dev/federation-domain-jwks"
)
const (
federationDomainKind = "FederationDomain"
)
// generateKey is stubbed out for the purpose of testing. The default behavior is to generate an EC key.
var generateKey = generateECKey //nolint:gochecknoglobals
func generateECKey(r io.Reader) (interface{}, error) {
return ecdsa.GenerateKey(elliptic.P256(), r)
}
// jwkController holds the fields necessary for the JWKS controller to communicate with FederationDomains and
// secrets, both via a cache and via the API.
type jwksWriterController struct {
jwksSecretLabels map[string]string
pinnipedClient pinnipedclientset.Interface
kubeClient kubernetes.Interface
federationDomainInformer configinformers.FederationDomainInformer
secretInformer corev1informers.SecretInformer
}
// NewJWKSWriterController returns a controllerlib.Controller that ensures a FederationDomain has a corresponding
// Secret that contains a valid active JWK and JWKS.
func NewJWKSWriterController(
jwksSecretLabels map[string]string,
kubeClient kubernetes.Interface,
pinnipedClient pinnipedclientset.Interface,
secretInformer corev1informers.SecretInformer,
federationDomainInformer configinformers.FederationDomainInformer,
withInformer pinnipedcontroller.WithInformerOptionFunc,
) controllerlib.Controller {
isSecretToSync := func(obj metav1.Object) bool {
return generator.IsFederationDomainSecretOfType(obj, jwksSecretTypeValue)
}
return controllerlib.New(
controllerlib.Config{
Name: "JWKSController",
Syncer: &jwksWriterController{
jwksSecretLabels: jwksSecretLabels,
kubeClient: kubeClient,
pinnipedClient: pinnipedClient,
secretInformer: secretInformer,
federationDomainInformer: federationDomainInformer,
},
},
// We want to be notified when a FederationDomain's secret gets updated or deleted. When this happens, we
// should get notified via the corresponding FederationDomain key.
withInformer(
secretInformer,
pinnipedcontroller.SimpleFilter(isSecretToSync, pinnipedcontroller.SecretIsControlledByParentFunc(isSecretToSync)),
controllerlib.InformerOption{},
),
// We want to be notified when anything happens to an FederationDomain.
withInformer(
federationDomainInformer,
pinnipedcontroller.MatchAnythingFilter(nil), // nil parent func is fine because each event is distinct
controllerlib.InformerOption{},
),
)
}
// Sync implements controllerlib.Syncer.
func (c *jwksWriterController) Sync(ctx controllerlib.Context) error {
federationDomain, err := c.federationDomainInformer.Lister().FederationDomains(ctx.Key.Namespace).Get(ctx.Key.Name)
notFound := k8serrors.IsNotFound(err)
if err != nil && !notFound {
return fmt.Errorf(
"failed to get %s/%s FederationDomain: %w",
ctx.Key.Namespace,
ctx.Key.Name,
err,
)
}
if notFound {
// The corresponding secret to this FederationDomain should have been garbage collected since it should have
// had this FederationDomain as its owner.
plog.Debug(
"FederationDomain deleted",
"federationdomain",
klog.KRef(ctx.Key.Namespace, ctx.Key.Name),
)
return nil
}
secretNeedsUpdate, err := c.secretNeedsUpdate(federationDomain)
if err != nil {
return fmt.Errorf("cannot determine secret status: %w", err)
}
if !secretNeedsUpdate {
// Secret is up to date - we are good to go.
plog.Debug(
"secret is up to date",
"federationdomain",
klog.KRef(ctx.Key.Namespace, ctx.Key.Name),
)
return nil
}
// If the FederationDomain does not have a secret associated with it, that secret does not exist, or the secret
// is invalid, we will generate a new secret (i.e., a JWKS).
secret, err := c.generateSecret(federationDomain)
if err != nil {
return fmt.Errorf("cannot generate secret: %w", err)
}
if err := c.createOrUpdateSecret(ctx.Context, secret); err != nil {
return fmt.Errorf("cannot create or update secret: %w", err)
}
plog.Debug("created/updated secret", "secret", klog.KObj(secret))
// Ensure that the FederationDomain points to the secret.
newFederationDomain := federationDomain.DeepCopy()
newFederationDomain.Status.Secrets.JWKS.Name = secret.Name
if err := c.updateFederationDomainStatus(ctx.Context, newFederationDomain); err != nil {
return fmt.Errorf("cannot update FederationDomain: %w", err)
}
plog.Debug("updated FederationDomain", "federationdomain", klog.KObj(newFederationDomain))
return nil
}
func (c *jwksWriterController) secretNeedsUpdate(federationDomain *configv1alpha1.FederationDomain) (bool, error) {
if federationDomain.Status.Secrets.JWKS.Name == "" {
// If the FederationDomain says it doesn't have a secret associated with it, then let's create one.
return true, nil
}
// This FederationDomain says it has a secret associated with it. Let's try to get it from the cache.
secret, err := c.secretInformer.Lister().Secrets(federationDomain.Namespace).Get(federationDomain.Status.Secrets.JWKS.Name)
notFound := k8serrors.IsNotFound(err)
if err != nil && !notFound {
return false, fmt.Errorf("cannot get secret: %w", err)
}
if notFound {
// If we can't find the secret, let's assume we need to create it.
return true, nil
}
if !isValid(secret) {
// If this secret is invalid, we need to generate a new one.
return true, nil
}
return false, nil
}
func (c *jwksWriterController) generateSecret(federationDomain *configv1alpha1.FederationDomain) (*corev1.Secret, error) {
// Note! This is where we could potentially add more handling of FederationDomain spec fields which tell us how
// this FederationDomain should sign and verify ID tokens (e.g., hardcoded token secret, gRPC
// connection to KMS, etc).
//
// For now, we just generate an new RSA keypair and put that in the secret.
key, err := generateKey(rand.Reader)
if err != nil {
return nil, fmt.Errorf("cannot generate key: %w", err)
}
jwk := jose.JSONWebKey{
Key: key,
KeyID: "pinniped-supervisor-key",
Algorithm: "ES256",
Use: "sig",
}
jwkData, err := json.Marshal(jwk)
if err != nil {
return nil, fmt.Errorf("cannot marshal jwk: %w", err)
}
jwks := jose.JSONWebKeySet{
Keys: []jose.JSONWebKey{jwk.Public()},
}
jwksData, err := json.Marshal(jwks)
if err != nil {
return nil, fmt.Errorf("cannot marshal jwks: %w", err)
}
s := corev1.Secret{
ObjectMeta: metav1.ObjectMeta{
Name: federationDomain.Name + "-jwks",
Namespace: federationDomain.Namespace,
Labels: c.jwksSecretLabels,
OwnerReferences: []metav1.OwnerReference{
*metav1.NewControllerRef(federationDomain, schema.GroupVersionKind{
Group: configv1alpha1.SchemeGroupVersion.Group,
Version: configv1alpha1.SchemeGroupVersion.Version,
Kind: federationDomainKind,
}),
},
},
Data: map[string][]byte{
activeJWKKey: jwkData,
jwksKey: jwksData,
},
Type: jwksSecretTypeValue,
}
return &s, nil
}
func (c *jwksWriterController) createOrUpdateSecret(
ctx context.Context,
newSecret *corev1.Secret,
) error {
secretClient := c.kubeClient.CoreV1().Secrets(newSecret.Namespace)
return retry.RetryOnConflict(retry.DefaultRetry, func() error {
oldSecret, err := secretClient.Get(ctx, newSecret.Name, metav1.GetOptions{})
notFound := k8serrors.IsNotFound(err)
if err != nil && !notFound {
return fmt.Errorf("cannot get secret: %w", err)
}
if notFound {
// New secret doesn't exist, so create it.
_, err := secretClient.Create(ctx, newSecret, metav1.CreateOptions{})
if err != nil {
return fmt.Errorf("cannot create secret: %w", err)
}
return nil
}
// New secret already exists, so ensure it is up to date.
if isValid(oldSecret) {
// If the secret already has valid JWK's, then we are good to go and we don't need an update.
return nil
}
oldSecret.Data = newSecret.Data
oldSecret.Type = jwksSecretTypeValue
_, err = secretClient.Update(ctx, oldSecret, metav1.UpdateOptions{})
return err
})
}
func (c *jwksWriterController) updateFederationDomainStatus(
ctx context.Context,
newFederationDomain *configv1alpha1.FederationDomain,
) error {
federationDomainClient := c.pinnipedClient.ConfigV1alpha1().FederationDomains(newFederationDomain.Namespace)
return retry.RetryOnConflict(retry.DefaultRetry, func() error {
oldFederationDomain, err := federationDomainClient.Get(ctx, newFederationDomain.Name, metav1.GetOptions{})
if err != nil {
return fmt.Errorf("cannot get FederationDomain: %w", err)
}
if newFederationDomain.Status.Secrets.JWKS.Name == oldFederationDomain.Status.Secrets.JWKS.Name {
// If the existing FederationDomain is up to date, we don't need to update it.
return nil
}
oldFederationDomain.Status.Secrets.JWKS.Name = newFederationDomain.Status.Secrets.JWKS.Name
_, err = federationDomainClient.UpdateStatus(ctx, oldFederationDomain, metav1.UpdateOptions{})
return err
})
}
// isValid returns whether the provided secret contains a valid active JWK and verification JWKS.
func isValid(secret *corev1.Secret) bool {
if secret.Type != jwksSecretTypeValue {
plog.Debug("secret does not have the expected type", "expectedType", jwksSecretTypeValue, "actualType", secret.Type)
return false
}
jwkData, ok := secret.Data[activeJWKKey]
if !ok {
plog.Debug("secret does not contain active jwk")
return false
}
var activeJWK jose.JSONWebKey
if err := json.Unmarshal(jwkData, &activeJWK); err != nil {
plog.Debug("cannot unmarshal active jwk", "err", err)
return false
}
if activeJWK.IsPublic() {
plog.Debug("active jwk is public", "keyid", activeJWK.KeyID)
return false
}
if !activeJWK.Valid() {
plog.Debug("active jwk is not valid", "keyid", activeJWK.KeyID)
return false
}
jwksData, ok := secret.Data[jwksKey]
if !ok {
plog.Debug("secret does not contain valid jwks")
}
var validJWKS jose.JSONWebKeySet
if err := json.Unmarshal(jwksData, &validJWKS); err != nil {
plog.Debug("cannot unmarshal valid jwks", "err", err)
return false
}
foundActiveJWK := false
for _, validJWK := range validJWKS.Keys {
if !validJWK.IsPublic() {
plog.Debug("jwks key is not public", "keyid", validJWK.KeyID)
return false
}
if !validJWK.Valid() {
plog.Debug("jwks key is not valid", "keyid", validJWK.KeyID)
return false
}
if validJWK.KeyID == activeJWK.KeyID {
foundActiveJWK = true
}
}
if !foundActiveJWK {
plog.Debug("did not find active jwk in valid jwks", "keyid", activeJWK.KeyID)
return false
}
return true
}