frostfs-s3-gw/pkg/bucket/policy/condition/nullfunc.go

106 lines
2.9 KiB
Go

/*
* MinIO Cloud Storage, (C) 2018 MinIO, Inc.
*
* 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 condition
import (
"fmt"
"net/http"
"reflect"
"strconv"
)
// nullFunc - Null condition function. It checks whether Key is not present in given
// values or not.
// For example,
// 1. if Key = S3XAmzCopySource and Value = true, at evaluate() it returns whether
// S3XAmzCopySource is NOT in given value map or not.
// 2. if Key = S3XAmzCopySource and Value = false, at evaluate() it returns whether
// S3XAmzCopySource is in given value map or not.
// https://docs.aws.amazon.com/IAM/latest/UserGuide/reference_policies_elements_condition_operators.html#Conditions_Null
type nullFunc struct {
k Key
value bool
}
// evaluate() - evaluates to check whether Key is present in given values or not.
// Depending on condition boolean value, this function returns true or false.
func (f nullFunc) evaluate(values map[string][]string) bool {
requestValue, ok := values[http.CanonicalHeaderKey(f.k.Name())]
if !ok {
requestValue = values[f.k.Name()]
}
if f.value {
return len(requestValue) == 0
}
return len(requestValue) != 0
}
// key() - returns condition key which is used by this condition function.
func (f nullFunc) key() Key {
return f.k
}
// name() - returns "Null" condition name.
func (f nullFunc) name() name {
return null
}
func (f nullFunc) String() string {
return fmt.Sprintf("%v:%v:%v", null, f.k, f.value)
}
// toMap - returns map representation of this function.
func (f nullFunc) toMap() map[Key]ValueSet {
if !f.k.IsValid() {
return nil
}
return map[Key]ValueSet{
f.k: NewValueSet(NewBoolValue(f.value)),
}
}
func newNullFunc(key Key, values ValueSet) (Function, error) {
if len(values) != 1 {
return nil, fmt.Errorf("only one value is allowed for Null condition")
}
var value bool
for v := range values {
switch v.GetType() {
case reflect.Bool:
value, _ = v.GetBool()
case reflect.String:
var err error
s, _ := v.GetString()
if value, err = strconv.ParseBool(s); err != nil {
return nil, fmt.Errorf("value must be a boolean string for Null condition")
}
default:
return nil, fmt.Errorf("value must be a boolean for Null condition")
}
}
return &nullFunc{key, value}, nil
}
// NewNullFunc - returns new Null function.
func NewNullFunc(key Key, value bool) (Function, error) {
return &nullFunc{key, value}, nil
}