118 lines
4.5 KiB
Go
118 lines
4.5 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 rbac implements the authorizer.Authorizer interface using roles base access control.
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package rbac
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import (
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utilerrors "k8s.io/apimachinery/pkg/util/errors"
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"k8s.io/apiserver/pkg/authentication/user"
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"k8s.io/apiserver/pkg/authorization/authorizer"
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"k8s.io/kubernetes/pkg/apis/rbac"
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rbacregistryvalidation "k8s.io/kubernetes/pkg/registry/rbac/validation"
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)
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type RoleToRuleMapper interface {
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// GetRoleReferenceRules attempts to resolve the role reference of a RoleBinding or ClusterRoleBinding. The passed namespace should be the namespace
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// of the role binding, the empty string if a cluster role binding.
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GetRoleReferenceRules(roleRef rbac.RoleRef, namespace string) ([]rbac.PolicyRule, error)
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}
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type SubjectAccessEvaluator struct {
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superUser string
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roleBindingLister rbacregistryvalidation.RoleBindingLister
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clusterRoleBindingLister rbacregistryvalidation.ClusterRoleBindingLister
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roleToRuleMapper RoleToRuleMapper
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}
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func NewSubjectAccessEvaluator(roles rbacregistryvalidation.RoleGetter, roleBindings rbacregistryvalidation.RoleBindingLister, clusterRoles rbacregistryvalidation.ClusterRoleGetter, clusterRoleBindings rbacregistryvalidation.ClusterRoleBindingLister, superUser string) *SubjectAccessEvaluator {
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subjectLocator := &SubjectAccessEvaluator{
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superUser: superUser,
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roleBindingLister: roleBindings,
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clusterRoleBindingLister: clusterRoleBindings,
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roleToRuleMapper: rbacregistryvalidation.NewDefaultRuleResolver(
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roles, roleBindings, clusterRoles, clusterRoleBindings,
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),
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}
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return subjectLocator
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}
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// AllowedSubjects returns the subjects that can perform an action and any errors encountered while computing the list.
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// It is possible to have both subjects and errors returned if some rolebindings couldn't be resolved, but others could be.
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func (r *SubjectAccessEvaluator) AllowedSubjects(requestAttributes authorizer.Attributes) ([]rbac.Subject, error) {
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subjects := []rbac.Subject{{Kind: rbac.GroupKind, APIGroup: rbac.GroupName, Name: user.SystemPrivilegedGroup}}
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if len(r.superUser) > 0 {
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subjects = append(subjects, rbac.Subject{Kind: rbac.UserKind, APIGroup: rbac.GroupName, Name: r.superUser})
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}
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errorlist := []error{}
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if clusterRoleBindings, err := r.clusterRoleBindingLister.ListClusterRoleBindings(); err != nil {
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errorlist = append(errorlist, err)
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} else {
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for _, clusterRoleBinding := range clusterRoleBindings {
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rules, err := r.roleToRuleMapper.GetRoleReferenceRules(clusterRoleBinding.RoleRef, "")
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if err != nil {
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// if we have an error, just keep track of it and keep processing. Since rules are additive,
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// missing a reference is bad, but we can continue with other rolebindings and still have a list
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// that does not contain any invalid values
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errorlist = append(errorlist, err)
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}
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if RulesAllow(requestAttributes, rules...) {
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subjects = append(subjects, clusterRoleBinding.Subjects...)
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}
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}
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}
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if namespace := requestAttributes.GetNamespace(); len(namespace) > 0 {
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if roleBindings, err := r.roleBindingLister.ListRoleBindings(namespace); err != nil {
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errorlist = append(errorlist, err)
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} else {
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for _, roleBinding := range roleBindings {
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rules, err := r.roleToRuleMapper.GetRoleReferenceRules(roleBinding.RoleRef, namespace)
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if err != nil {
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// if we have an error, just keep track of it and keep processing. Since rules are additive,
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// missing a reference is bad, but we can continue with other rolebindings and still have a list
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// that does not contain any invalid values
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errorlist = append(errorlist, err)
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}
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if RulesAllow(requestAttributes, rules...) {
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subjects = append(subjects, roleBinding.Subjects...)
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}
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}
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}
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}
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dedupedSubjects := []rbac.Subject{}
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for _, subject := range subjects {
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found := false
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for _, curr := range dedupedSubjects {
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if curr == subject {
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found = true
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break
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}
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}
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if !found {
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dedupedSubjects = append(dedupedSubjects, subject)
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}
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}
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return subjects, utilerrors.NewAggregate(errorlist)
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}
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