251 lines
8.5 KiB
Go
251 lines
8.5 KiB
Go
/*
|
|
Copyright 2016 The Kubernetes Authors.
|
|
|
|
Licensed under the Apache License, Version 2.0 (the "License");
|
|
you may not use this file except in compliance with the License.
|
|
You may obtain a copy of the License at
|
|
|
|
http://www.apache.org/licenses/LICENSE-2.0
|
|
|
|
Unless required by applicable law or agreed to in writing, software
|
|
distributed under the License is distributed on an "AS IS" BASIS,
|
|
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
See the License for the specific language governing permissions and
|
|
limitations under the License.
|
|
*/
|
|
|
|
// Package webhook implements the authenticator.Token interface using HTTP webhooks.
|
|
package webhook
|
|
|
|
import (
|
|
"context"
|
|
"errors"
|
|
"fmt"
|
|
"time"
|
|
|
|
authenticationv1 "k8s.io/api/authentication/v1"
|
|
authenticationv1beta1 "k8s.io/api/authentication/v1beta1"
|
|
"k8s.io/apimachinery/pkg/runtime"
|
|
"k8s.io/apimachinery/pkg/runtime/schema"
|
|
"k8s.io/apiserver/pkg/authentication/authenticator"
|
|
"k8s.io/apiserver/pkg/authentication/user"
|
|
"k8s.io/apiserver/pkg/util/webhook"
|
|
"k8s.io/client-go/kubernetes/scheme"
|
|
authenticationv1client "k8s.io/client-go/kubernetes/typed/authentication/v1"
|
|
"k8s.io/klog"
|
|
)
|
|
|
|
const retryBackoff = 500 * time.Millisecond
|
|
|
|
// Ensure WebhookTokenAuthenticator implements the authenticator.Token interface.
|
|
var _ authenticator.Token = (*WebhookTokenAuthenticator)(nil)
|
|
|
|
type tokenReviewer interface {
|
|
CreateContext(ctx context.Context, review *authenticationv1.TokenReview) (*authenticationv1.TokenReview, error)
|
|
}
|
|
|
|
type WebhookTokenAuthenticator struct {
|
|
tokenReview tokenReviewer
|
|
initialBackoff time.Duration
|
|
implicitAuds authenticator.Audiences
|
|
}
|
|
|
|
// NewFromInterface creates a webhook authenticator using the given tokenReview
|
|
// client. It is recommend to wrap this authenticator with the token cache
|
|
// authenticator implemented in
|
|
// k8s.io/apiserver/pkg/authentication/token/cache.
|
|
func NewFromInterface(tokenReview authenticationv1client.TokenReviewInterface, implicitAuds authenticator.Audiences) (*WebhookTokenAuthenticator, error) {
|
|
return newWithBackoff(tokenReview, retryBackoff, implicitAuds)
|
|
}
|
|
|
|
// New creates a new WebhookTokenAuthenticator from the provided kubeconfig
|
|
// file. It is recommend to wrap this authenticator with the token cache
|
|
// authenticator implemented in
|
|
// k8s.io/apiserver/pkg/authentication/token/cache.
|
|
func New(kubeConfigFile string, version string, implicitAuds authenticator.Audiences) (*WebhookTokenAuthenticator, error) {
|
|
tokenReview, err := tokenReviewInterfaceFromKubeconfig(kubeConfigFile, version)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
return newWithBackoff(tokenReview, retryBackoff, implicitAuds)
|
|
}
|
|
|
|
// newWithBackoff allows tests to skip the sleep.
|
|
func newWithBackoff(tokenReview tokenReviewer, initialBackoff time.Duration, implicitAuds authenticator.Audiences) (*WebhookTokenAuthenticator, error) {
|
|
return &WebhookTokenAuthenticator{tokenReview, initialBackoff, implicitAuds}, nil
|
|
}
|
|
|
|
// AuthenticateToken implements the authenticator.Token interface.
|
|
func (w *WebhookTokenAuthenticator) AuthenticateToken(ctx context.Context, token string) (*authenticator.Response, bool, error) {
|
|
// We take implicit audiences of the API server at WebhookTokenAuthenticator
|
|
// construction time. The outline of how we validate audience here is:
|
|
//
|
|
// * if the ctx is not audience limited, don't do any audience validation.
|
|
// * if ctx is audience-limited, add the audiences to the tokenreview spec
|
|
// * if the tokenreview returns with audiences in the status that intersect
|
|
// with the audiences in the ctx, copy into the response and return success
|
|
// * if the tokenreview returns without an audience in the status, ensure
|
|
// the ctx audiences intersect with the implicit audiences, and set the
|
|
// intersection in the response.
|
|
// * otherwise return unauthenticated.
|
|
wantAuds, checkAuds := authenticator.AudiencesFrom(ctx)
|
|
r := &authenticationv1.TokenReview{
|
|
Spec: authenticationv1.TokenReviewSpec{
|
|
Token: token,
|
|
Audiences: wantAuds,
|
|
},
|
|
}
|
|
var (
|
|
result *authenticationv1.TokenReview
|
|
err error
|
|
auds authenticator.Audiences
|
|
)
|
|
webhook.WithExponentialBackoff(ctx, w.initialBackoff, func() error {
|
|
result, err = w.tokenReview.CreateContext(ctx, r)
|
|
return err
|
|
}, webhook.DefaultShouldRetry)
|
|
if err != nil {
|
|
// An error here indicates bad configuration or an outage. Log for debugging.
|
|
klog.Errorf("Failed to make webhook authenticator request: %v", err)
|
|
return nil, false, err
|
|
}
|
|
|
|
if checkAuds {
|
|
gotAuds := w.implicitAuds
|
|
if len(result.Status.Audiences) > 0 {
|
|
gotAuds = result.Status.Audiences
|
|
}
|
|
auds = wantAuds.Intersect(gotAuds)
|
|
if len(auds) == 0 {
|
|
return nil, false, nil
|
|
}
|
|
}
|
|
|
|
r.Status = result.Status
|
|
if !r.Status.Authenticated {
|
|
var err error
|
|
if len(r.Status.Error) != 0 {
|
|
err = errors.New(r.Status.Error)
|
|
}
|
|
return nil, false, err
|
|
}
|
|
|
|
var extra map[string][]string
|
|
if r.Status.User.Extra != nil {
|
|
extra = map[string][]string{}
|
|
for k, v := range r.Status.User.Extra {
|
|
extra[k] = v
|
|
}
|
|
}
|
|
|
|
return &authenticator.Response{
|
|
User: &user.DefaultInfo{
|
|
Name: r.Status.User.Username,
|
|
UID: r.Status.User.UID,
|
|
Groups: r.Status.User.Groups,
|
|
Extra: extra,
|
|
},
|
|
Audiences: auds,
|
|
}, true, nil
|
|
}
|
|
|
|
// tokenReviewInterfaceFromKubeconfig builds a client from the specified kubeconfig file,
|
|
// and returns a TokenReviewInterface that uses that client. Note that the client submits TokenReview
|
|
// requests to the exact path specified in the kubeconfig file, so arbitrary non-API servers can be targeted.
|
|
func tokenReviewInterfaceFromKubeconfig(kubeConfigFile string, version string) (tokenReviewer, error) {
|
|
localScheme := runtime.NewScheme()
|
|
if err := scheme.AddToScheme(localScheme); err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
switch version {
|
|
case authenticationv1.SchemeGroupVersion.Version:
|
|
groupVersions := []schema.GroupVersion{authenticationv1.SchemeGroupVersion}
|
|
if err := localScheme.SetVersionPriority(groupVersions...); err != nil {
|
|
return nil, err
|
|
}
|
|
gw, err := webhook.NewGenericWebhook(localScheme, scheme.Codecs, kubeConfigFile, groupVersions, 0)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
return &tokenReviewV1Client{gw}, nil
|
|
|
|
case authenticationv1beta1.SchemeGroupVersion.Version:
|
|
groupVersions := []schema.GroupVersion{authenticationv1beta1.SchemeGroupVersion}
|
|
if err := localScheme.SetVersionPriority(groupVersions...); err != nil {
|
|
return nil, err
|
|
}
|
|
gw, err := webhook.NewGenericWebhook(localScheme, scheme.Codecs, kubeConfigFile, groupVersions, 0)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
return &tokenReviewV1beta1Client{gw}, nil
|
|
|
|
default:
|
|
return nil, fmt.Errorf(
|
|
"unsupported authentication webhook version %q, supported versions are %q, %q",
|
|
version,
|
|
authenticationv1.SchemeGroupVersion.Version,
|
|
authenticationv1beta1.SchemeGroupVersion.Version,
|
|
)
|
|
}
|
|
|
|
}
|
|
|
|
type tokenReviewV1Client struct {
|
|
w *webhook.GenericWebhook
|
|
}
|
|
|
|
func (t *tokenReviewV1Client) CreateContext(ctx context.Context, review *authenticationv1.TokenReview) (*authenticationv1.TokenReview, error) {
|
|
result := &authenticationv1.TokenReview{}
|
|
err := t.w.RestClient.Post().Context(ctx).Body(review).Do().Into(result)
|
|
return result, err
|
|
}
|
|
|
|
type tokenReviewV1beta1Client struct {
|
|
w *webhook.GenericWebhook
|
|
}
|
|
|
|
func (t *tokenReviewV1beta1Client) CreateContext(ctx context.Context, review *authenticationv1.TokenReview) (*authenticationv1.TokenReview, error) {
|
|
v1beta1Review := &authenticationv1beta1.TokenReview{Spec: v1SpecToV1beta1Spec(&review.Spec)}
|
|
v1beta1Result := &authenticationv1beta1.TokenReview{}
|
|
err := t.w.RestClient.Post().Context(ctx).Body(v1beta1Review).Do().Into(v1beta1Result)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
review.Status = v1beta1StatusToV1Status(&v1beta1Result.Status)
|
|
return review, nil
|
|
}
|
|
|
|
func v1SpecToV1beta1Spec(in *authenticationv1.TokenReviewSpec) authenticationv1beta1.TokenReviewSpec {
|
|
return authenticationv1beta1.TokenReviewSpec{
|
|
Token: in.Token,
|
|
Audiences: in.Audiences,
|
|
}
|
|
}
|
|
|
|
func v1beta1StatusToV1Status(in *authenticationv1beta1.TokenReviewStatus) authenticationv1.TokenReviewStatus {
|
|
return authenticationv1.TokenReviewStatus{
|
|
Authenticated: in.Authenticated,
|
|
User: v1beta1UserToV1User(in.User),
|
|
Audiences: in.Audiences,
|
|
Error: in.Error,
|
|
}
|
|
}
|
|
|
|
func v1beta1UserToV1User(u authenticationv1beta1.UserInfo) authenticationv1.UserInfo {
|
|
var extra map[string]authenticationv1.ExtraValue
|
|
if u.Extra != nil {
|
|
extra = make(map[string]authenticationv1.ExtraValue, len(u.Extra))
|
|
for k, v := range u.Extra {
|
|
extra[k] = authenticationv1.ExtraValue(v)
|
|
}
|
|
}
|
|
return authenticationv1.UserInfo{
|
|
Username: u.Username,
|
|
UID: u.UID,
|
|
Groups: u.Groups,
|
|
Extra: extra,
|
|
}
|
|
}
|