113 lines
3.4 KiB
Go
113 lines
3.4 KiB
Go
/*
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Copyright 2016 The Kubernetes Authors.
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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package certificates
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import (
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"fmt"
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"reflect"
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"strings"
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utilruntime "k8s.io/apimachinery/pkg/util/runtime"
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certificates "k8s.io/kubernetes/pkg/apis/certificates/v1alpha1"
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clientcertificates "k8s.io/kubernetes/pkg/client/clientset_generated/clientset/typed/certificates/v1alpha1"
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)
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// groupApprover implements AutoApprover for signing Kubelet certificates.
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type groupApprover struct {
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client clientcertificates.CertificateSigningRequestInterface
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approveAllKubeletCSRsForGroup string
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}
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// NewGroupApprover creates an approver that accepts any CSR requests where the subject group contains approveAllKubeletCSRsForGroup.
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func NewGroupApprover(client clientcertificates.CertificateSigningRequestInterface, approveAllKubeletCSRsForGroup string) AutoApprover {
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return &groupApprover{
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client: client,
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approveAllKubeletCSRsForGroup: approveAllKubeletCSRsForGroup,
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}
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}
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func (cc *groupApprover) AutoApprove(csr *certificates.CertificateSigningRequest) (*certificates.CertificateSigningRequest, error) {
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// short-circuit if we're not auto-approving
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if cc.approveAllKubeletCSRsForGroup == "" {
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return csr, nil
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}
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// short-circuit if we're already approved or denied
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if approved, denied := getCertApprovalCondition(&csr.Status); approved || denied {
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return csr, nil
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}
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isKubeletBootstrapGroup := false
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for _, g := range csr.Spec.Groups {
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if g == cc.approveAllKubeletCSRsForGroup {
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isKubeletBootstrapGroup = true
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break
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}
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}
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if !isKubeletBootstrapGroup {
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return csr, nil
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}
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x509cr, err := certificates.ParseCSR(csr)
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if err != nil {
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utilruntime.HandleError(fmt.Errorf("unable to parse csr %q: %v", csr.Name, err))
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return csr, nil
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}
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if !reflect.DeepEqual([]string{"system:nodes"}, x509cr.Subject.Organization) {
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return csr, nil
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}
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if !strings.HasPrefix(x509cr.Subject.CommonName, "system:node:") {
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return csr, nil
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}
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if len(x509cr.DNSNames)+len(x509cr.EmailAddresses)+len(x509cr.IPAddresses) != 0 {
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return csr, nil
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}
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if !hasExactUsages(csr, kubeletClientUsages) {
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return csr, nil
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}
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csr.Status.Conditions = append(csr.Status.Conditions, certificates.CertificateSigningRequestCondition{
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Type: certificates.CertificateApproved,
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Reason: "AutoApproved",
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Message: "Auto approving of all kubelet CSRs is enabled on the controller manager",
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})
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return cc.client.UpdateApproval(csr)
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}
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var kubeletClientUsages = []certificates.KeyUsage{
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certificates.UsageKeyEncipherment,
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certificates.UsageDigitalSignature,
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certificates.UsageClientAuth,
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}
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func hasExactUsages(csr *certificates.CertificateSigningRequest, usages []certificates.KeyUsage) bool {
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if len(usages) != len(csr.Spec.Usages) {
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return false
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}
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usageMap := map[certificates.KeyUsage]struct{}{}
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for _, u := range usages {
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usageMap[u] = struct{}{}
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}
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for _, u := range csr.Spec.Usages {
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if _, ok := usageMap[u]; !ok {
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return false
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}
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}
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return true
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}
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