minio/pkg/iam/policy/resource.go

144 lines
3.7 KiB
Go

// Copyright (c) 2015-2021 MinIO, Inc.
//
// This file is part of MinIO Object Storage stack
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
package iampolicy
import (
"encoding/json"
"path"
"strings"
"github.com/minio/minio/pkg/bucket/policy/condition"
"github.com/minio/minio/pkg/wildcard"
)
// ResourceARNPrefix - resource ARN prefix as per AWS S3 specification.
const ResourceARNPrefix = "arn:aws:s3:::"
// Resource - resource in policy statement.
type Resource struct {
BucketName string
Pattern string
}
func (r Resource) isBucketPattern() bool {
return !strings.Contains(r.Pattern, "/") || r.Pattern == "*"
}
func (r Resource) isObjectPattern() bool {
return strings.Contains(r.Pattern, "/") || strings.Contains(r.BucketName, "*") || r.Pattern == "*/*"
}
// IsValid - checks whether Resource is valid or not.
func (r Resource) IsValid() bool {
return r.Pattern != ""
}
// MatchResource matches object name with resource pattern only.
func (r Resource) MatchResource(resource string) bool {
return r.Match(resource, nil)
}
// Match - matches object name with resource pattern, including specific conditionals.
func (r Resource) Match(resource string, conditionValues map[string][]string) bool {
pattern := r.Pattern
for _, key := range condition.CommonKeys {
// Empty values are not supported for policy variables.
if rvalues, ok := conditionValues[key.Name()]; ok && rvalues[0] != "" {
pattern = strings.Replace(pattern, key.VarName(), rvalues[0], -1)
}
}
if cp := path.Clean(resource); cp != "." && cp == pattern {
return true
}
return wildcard.Match(pattern, resource)
}
// MarshalJSON - encodes Resource to JSON data.
func (r Resource) MarshalJSON() ([]byte, error) {
if !r.IsValid() {
return nil, Errorf("invalid resource %v", r)
}
return json.Marshal(r.String())
}
func (r Resource) String() string {
return ResourceARNPrefix + r.Pattern
}
// UnmarshalJSON - decodes JSON data to Resource.
func (r *Resource) UnmarshalJSON(data []byte) error {
var s string
if err := json.Unmarshal(data, &s); err != nil {
return err
}
parsedResource, err := parseResource(s)
if err != nil {
return err
}
*r = parsedResource
return nil
}
// Validate - validates Resource is for given bucket or not.
func (r Resource) Validate() error {
if !r.IsValid() {
return Errorf("invalid resource")
}
return nil
}
// parseResource - parses string to Resource.
func parseResource(s string) (Resource, error) {
if !strings.HasPrefix(s, ResourceARNPrefix) {
return Resource{}, Errorf("invalid resource '%v'", s)
}
pattern := strings.TrimPrefix(s, ResourceARNPrefix)
tokens := strings.SplitN(pattern, "/", 2)
bucketName := tokens[0]
if bucketName == "" {
return Resource{}, Errorf("invalid resource format '%v'", s)
}
return Resource{
BucketName: bucketName,
Pattern: pattern,
}, nil
}
// NewResource - creates new resource.
func NewResource(bucketName, keyName string) Resource {
pattern := bucketName
if keyName != "" {
if !strings.HasPrefix(keyName, "/") {
pattern += "/"
}
pattern += keyName
}
return Resource{
BucketName: bucketName,
Pattern: pattern,
}
}