feat: impl. new protol design & new head

internal/algo/hash.go

@@ -0,0 +1,47 @@
+package algo
+
+import (
+	"bytes"
+	"crypto/md5"
+	"encoding/binary"
+	"encoding/hex"
+
+	"github.com/fumiama/WireGold/config"
+	"github.com/fumiama/blake2b-simd"
+	"github.com/sirupsen/logrus"
+)
+
+// Blake2bHash8 生成 data 的 blake2b hash, 返回前八位
+func Blake2bHash8(precrc64 uint64, data []byte) uint64 {
+	var tgt [32]byte
+	h := blake2b.New256()
+	binary.LittleEndian.PutUint64(tgt[:8], precrc64)
+	_, _ = h.Write(tgt[:8])
+	_, _ = h.Write(data)
+	b := h.Sum(tgt[:0])[:8]
+	if config.ShowDebugLog {
+		logrus.Debugln("[algo] blk2b hash:", hex.EncodeToString(b))
+	}
+	return binary.LittleEndian.Uint64(b)
+}
+
+// IsVaildBlake2bHash8 在收齐全部分片并解密后验证 packet 合法性
+func IsVaildBlake2bHash8(precrc64 uint64, hash8data []byte) bool {
+	var tgt [32]byte
+	h := blake2b.New256()
+	binary.LittleEndian.PutUint64(tgt[:8], precrc64)
+	_, _ = h.Write(tgt[:8])
+	_, _ = h.Write(hash8data[8:])
+	b := h.Sum(tgt[:0])[:8]
+	if config.ShowDebugLog {
+		logrus.Debugln("[algo] blk2b sum calulated:", hex.EncodeToString(b))
+		logrus.Debugln("[algo] blk2b sum in packet:", hex.EncodeToString(hash8data[:8]))
+	}
+	return bytes.Equal(b, hash8data[:8])
+}
+
+// MD5Hash8 calculate packet header checksum
+func MD5Hash8(data []byte) uint64 {
+	m := md5.Sum(data)
+	return binary.LittleEndian.Uint64(m[:8])
+}