Add sha256 and sha512 windows compatibility layer

pkg/utils/crypto/sha256/sha256_darwin.go

@@ -1,3 +1,19 @@
+/*
+ * Minimalist Object Storage, (C) 2014 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 sha256
 
 import (

pkg/utils/crypto/sha256/sha256_windows.go

@@ -0,0 +1,47 @@
+/*
+ * Minimalist Object Storage, (C) 2014 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 sha256
+
+import (
+	"io"
+
+	"crypto/sha256"
+)
+
+// Sum256 - single caller sha256 helper
+func Sum256(data []byte) []byte {
+	d := sha256.New()
+	d.Write(data)
+	return d.Sum(nil)
+}
+
+// Sum - io.Reader based streaming sha256 helper
+func Sum(reader io.Reader) ([]byte, error) {
+	d := sha256.New()
+	var err error
+	for err == nil {
+		length := 0
+		byteBuffer := make([]byte, 1024*1024)
+		length, err = reader.Read(byteBuffer)
+		byteBuffer = byteBuffer[0:length]
+		d.Write(byteBuffer)
+	}
+	if err != io.EOF {
+		return nil, err
+	}
+	return d.Sum(nil), nil
+}