Enhance policy handling to support SSE and WORM (#5790)

- remove old bucket policy handling
- add new policy handling
- add new policy handling unit tests

This patch brings support to bucket policy to have more control not
limiting to anonymous.  Bucket owner controls to allow/deny any rest
API.

For example server side encryption can be controlled by allowing
PUT/GET objects with encryptions including bucket owner.

pkg/policy/condition/valueset_test.go

@@ -0,0 +1,118 @@
+/*
+ * 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 (
+	"encoding/json"
+	"reflect"
+	"testing"
+)
+
+func TestValueSetAdd(t *testing.T) {
+	testCases := []struct {
+		value          Value
+		expectedResult ValueSet
+	}{
+		{NewBoolValue(true), NewValueSet(NewBoolValue(true))},
+		{NewIntValue(7), NewValueSet(NewIntValue(7))},
+		{NewStringValue("foo"), NewValueSet(NewStringValue("foo"))},
+	}
+
+	for i, testCase := range testCases {
+		result := NewValueSet()
+		result.Add(testCase.value)
+
+		if !reflect.DeepEqual(result, testCase.expectedResult) {
+			t.Fatalf("case %v: expected: %v, got: %v\n", i+1, testCase.expectedResult, result)
+		}
+	}
+}
+
+func TestValueSetMarshalJSON(t *testing.T) {
+	testCases := []struct {
+		set            ValueSet
+		expectedResult string
+		expectErr      bool
+	}{
+		{NewValueSet(NewBoolValue(true)), `[true]`, false},
+		{NewValueSet(NewIntValue(7)), `[7]`, false},
+		{NewValueSet(NewStringValue("foo")), `["foo"]`, false},
+		{NewValueSet(NewBoolValue(true)), `[true]`, false},
+		{NewValueSet(NewStringValue("7")), `["7"]`, false},
+		{NewValueSet(NewStringValue("foo")), `["foo"]`, false},
+		{make(ValueSet), "", true},
+	}
+
+	for i, testCase := range testCases {
+		result, err := json.Marshal(testCase.set)
+		expectErr := (err != nil)
+
+		if expectErr != testCase.expectErr {
+			t.Fatalf("case %v: error: expected: %v, got: %v\n", i+1, testCase.expectErr, expectErr)
+		}
+
+		if !testCase.expectErr {
+			if string(result) != testCase.expectedResult {
+				t.Fatalf("case %v: result: expected: %v, got: %v\n", i+1, testCase.expectedResult, string(result))
+			}
+		}
+	}
+}
+
+func TestValueSetUnmarshalJSON(t *testing.T) {
+	set1 := NewValueSet(
+		NewBoolValue(true),
+		NewStringValue("false"),
+		NewIntValue(7),
+		NewStringValue("7"),
+		NewStringValue("foo"),
+		NewStringValue("192.168.1.100/24"),
+	)
+
+	testCases := []struct {
+		data           []byte
+		expectedResult ValueSet
+		expectErr      bool
+	}{
+		{[]byte(`true`), NewValueSet(NewBoolValue(true)), false},
+		{[]byte(`7`), NewValueSet(NewIntValue(7)), false},
+		{[]byte(`"foo"`), NewValueSet(NewStringValue("foo")), false},
+		{[]byte(`[true]`), NewValueSet(NewBoolValue(true)), false},
+		{[]byte(`[7]`), NewValueSet(NewIntValue(7)), false},
+		{[]byte(`["foo"]`), NewValueSet(NewStringValue("foo")), false},
+		{[]byte(`[true, "false", 7, "7", "foo", "192.168.1.100/24"]`), set1, false},
+		{[]byte(`{}`), nil, true},           // Unsupported data.
+		{[]byte(`[]`), nil, true},           // Empty array.
+		{[]byte(`[7, 7, true]`), nil, true}, // Duplicate value.
+	}
+
+	for i, testCase := range testCases {
+		result := make(ValueSet)
+		err := json.Unmarshal(testCase.data, &result)
+		expectErr := (err != nil)
+
+		if expectErr != testCase.expectErr {
+			t.Fatalf("case %v: error: expected: %v, got: %v\n", i+1, testCase.expectErr, expectErr)
+		}
+
+		if !testCase.expectErr {
+			if !reflect.DeepEqual(result, testCase.expectedResult) {
+				t.Fatalf("case %v: result: expected: %v, got: %v\n", i+1, testCase.expectedResult, result)
+			}
+		}
+	}
+}