feat: impl. encoding.BinaryMarshaler/Unmarshaler

binary.go

@@ -0,0 +1,97 @@
+/*
+ * Copyright (c) 2025 Fumiama Minamoto.
+ *
+ * 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 blake2b
+
+import (
+	"bytes"
+	"encoding/binary"
+	"unsafe"
+)
+
+// MarshalBinary marshals current digest status into bytes.
+func (d *digest) MarshalBinary() ([]byte, error) {
+	buf := bytes.NewBuffer(make([]byte, 0, unsafe.Sizeof(*d)))
+	_ = binary.Write(buf, binary.BigEndian, &d.h)
+	_ = binary.Write(buf, binary.BigEndian, &d.t)
+	_ = binary.Write(buf, binary.BigEndian, &d.f)
+	_ = binary.Write(buf, binary.BigEndian, &d.x)
+	_ = binary.Write(buf, binary.BigEndian, int64(d.nx))
+	_ = binary.Write(buf, binary.BigEndian, &d.ih)
+	_ = binary.Write(buf, binary.BigEndian, &d.paddedKey)
+	if d.isKeyed {
+		buf.WriteByte(1)
+	} else {
+		buf.WriteByte(0)
+	}
+	buf.WriteByte(d.size)
+	if d.isLastNode {
+		buf.WriteByte(1)
+	} else {
+		buf.WriteByte(0)
+	}
+	return buf.Bytes(), nil
+}
+
+// UnmarshalBinary loads current digest status from bytes.
+func (d *digest) UnmarshalBinary(data []byte) error {
+	r := bytes.NewReader(data)
+	err := binary.Read(r, binary.BigEndian, &d.h)
+	if err != nil {
+		return err
+	}
+	err = binary.Read(r, binary.BigEndian, &d.t)
+	if err != nil {
+		return err
+	}
+	err = binary.Read(r, binary.BigEndian, &d.f)
+	if err != nil {
+		return err
+	}
+	err = binary.Read(r, binary.BigEndian, &d.x)
+	if err != nil {
+		return err
+	}
+	nx := int64(0)
+	err = binary.Read(r, binary.BigEndian, &nx)
+	if err != nil {
+		return err
+	}
+	d.nx = int(nx)
+	err = binary.Read(r, binary.BigEndian, &d.ih)
+	if err != nil {
+		return err
+	}
+	err = binary.Read(r, binary.BigEndian, &d.paddedKey)
+	if err != nil {
+		return err
+	}
+	b, err := r.ReadByte()
+	if err != nil {
+		return err
+	}
+	d.isKeyed = b != 0
+	d.size, err = r.ReadByte()
+	if err != nil {
+		return err
+	}
+	b, err = r.ReadByte()
+	if err != nil {
+		return err
+	}
+	d.isLastNode = b != 0
+	return nil
+}