storage.go

Documentation: k8s.io/kubernetes/pkg/registry/rbac/role/policybased

     1  /*
     2  Copyright 2016 The Kubernetes Authors.
     3  
     4  Licensed under the Apache License, Version 2.0 (the "License");
     5  you may not use this file except in compliance with the License.
     6  You may obtain a copy of the License at
     7  
     8      http://www.apache.org/licenses/LICENSE-2.0
     9  
    10  Unless required by applicable law or agreed to in writing, software
    11  distributed under the License is distributed on an "AS IS" BASIS,
    12  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13  See the License for the specific language governing permissions and
    14  limitations under the License.
    15  */
    16  
    17  // Package policybased implements a standard storage for Role that prevents privilege escalation.
    18  package policybased
    19  
    20  import (
    21  	"context"
    22  
    23  	"k8s.io/apimachinery/pkg/api/errors"
    24  	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
    25  	"k8s.io/apimachinery/pkg/runtime"
    26  	"k8s.io/apiserver/pkg/authorization/authorizer"
    27  	"k8s.io/apiserver/pkg/registry/rest"
    28  	kapihelper "k8s.io/kubernetes/pkg/apis/core/helper"
    29  	"k8s.io/kubernetes/pkg/apis/rbac"
    30  	rbacregistry "k8s.io/kubernetes/pkg/registry/rbac"
    31  	rbacregistryvalidation "k8s.io/kubernetes/pkg/registry/rbac/validation"
    32  )
    33  
    34  var groupResource = rbac.Resource("roles")
    35  
    36  type Storage struct {
    37  	rest.StandardStorage
    38  
    39  	authorizer authorizer.Authorizer
    40  
    41  	ruleResolver rbacregistryvalidation.AuthorizationRuleResolver
    42  }
    43  
    44  func NewStorage(s rest.StandardStorage, authorizer authorizer.Authorizer, ruleResolver rbacregistryvalidation.AuthorizationRuleResolver) *Storage {
    45  	return &Storage{s, authorizer, ruleResolver}
    46  }
    47  
    48  // Destroy cleans up resources on shutdown.
    49  func (r *Storage) Destroy() {
    50  	r.StandardStorage.Destroy()
    51  }
    52  
    53  func (r *Storage) NamespaceScoped() bool {
    54  	return true
    55  }
    56  
    57  func (r *Storage) StorageVersion() runtime.GroupVersioner {
    58  	svp, ok := r.StandardStorage.(rest.StorageVersionProvider)
    59  	if !ok {
    60  		return nil
    61  	}
    62  	return svp.StorageVersion()
    63  }
    64  
    65  var _ rest.StorageVersionProvider = &Storage{}
    66  
    67  func (s *Storage) Create(ctx context.Context, obj runtime.Object, createValidation rest.ValidateObjectFunc, options *metav1.CreateOptions) (runtime.Object, error) {
    68  	if rbacregistry.EscalationAllowed(ctx) || rbacregistry.RoleEscalationAuthorized(ctx, s.authorizer) {
    69  		return s.StandardStorage.Create(ctx, obj, createValidation, options)
    70  	}
    71  
    72  	role := obj.(*rbac.Role)
    73  	rules := role.Rules
    74  	if err := rbacregistryvalidation.ConfirmNoEscalationInternal(ctx, s.ruleResolver, rules); err != nil {
    75  		return nil, errors.NewForbidden(groupResource, role.Name, err)
    76  	}
    77  	return s.StandardStorage.Create(ctx, obj, createValidation, options)
    78  }
    79  
    80  func (s *Storage) Update(ctx context.Context, name string, obj rest.UpdatedObjectInfo, createValidation rest.ValidateObjectFunc, updateValidation rest.ValidateObjectUpdateFunc, forceAllowCreate bool, options *metav1.UpdateOptions) (runtime.Object, bool, error) {
    81  	if rbacregistry.EscalationAllowed(ctx) || rbacregistry.RoleEscalationAuthorized(ctx, s.authorizer) {
    82  		return s.StandardStorage.Update(ctx, name, obj, createValidation, updateValidation, forceAllowCreate, options)
    83  	}
    84  
    85  	nonEscalatingInfo := rest.WrapUpdatedObjectInfo(obj, func(ctx context.Context, obj runtime.Object, oldObj runtime.Object) (runtime.Object, error) {
    86  		role := obj.(*rbac.Role)
    87  
    88  		// if we're only mutating fields needed for the GC to eventually delete this obj, return
    89  		if rbacregistry.IsOnlyMutatingGCFields(obj, oldObj, kapihelper.Semantic) {
    90  			return obj, nil
    91  		}
    92  
    93  		rules := role.Rules
    94  		if err := rbacregistryvalidation.ConfirmNoEscalationInternal(ctx, s.ruleResolver, rules); err != nil {
    95  			return nil, errors.NewForbidden(groupResource, role.Name, err)
    96  		}
    97  		return obj, nil
    98  	})
    99  
   100  	return s.StandardStorage.Update(ctx, name, nonEscalatingInfo, createValidation, updateValidation, forceAllowCreate, options)
   101  }
   102  
   103  var _ rest.SingularNameProvider = &Storage{}
   104  
   105  func (s *Storage) GetSingularName() string {
   106  	snp, ok := s.StandardStorage.(rest.SingularNameProvider)
   107  	if !ok {
   108  		return ""
   109  	}
   110  	return snp.GetSingularName()
   111  }
   112
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