Rename pkg/{tagging,lifecycle} to pkg/bucket sub-directory (#8892)

Rename to allow for more such features to come in a more
proper hierarchical manner.

pkg/bucket/policy/resource.go

@@ -0,0 +1,139 @@
+/*
+ * 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 policy
+
+import (
+	"encoding/json"
+	"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, "/")
+}
+
+func (r Resource) isObjectPattern() bool {
+	return strings.Contains(r.Pattern, "/") || strings.Contains(r.BucketName, "*")
+}
+
+// IsValid - checks whether Resource is valid or not.
+func (r Resource) IsValid() bool {
+	return r.BucketName != "" && r.Pattern != ""
+}
+
+// Match - matches object name with resource pattern.
+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)
+		}
+	}
+
+	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(bucketName string) error {
+	if !r.IsValid() {
+		return Errorf("invalid resource")
+	}
+
+	if !wildcard.Match(r.BucketName, bucketName) {
+		return Errorf("bucket name does not match")
+	}
+
+	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,
+	}
+}