move uuid.Next to protocol

common/protocol/id.go

@@ -56,11 +56,25 @@ func NewID(uuid uuid.UUID) *ID {
 	return id
 }
 
+func nextId(u *uuid.UUID) uuid.UUID {
+	md5hash := md5.New()
+	common.Must2(md5hash.Write(u.Bytes()))
+	common.Must2(md5hash.Write([]byte("16167dc8-16b6-4e6d-b8bb-65dd68113a81")))
+	var newid uuid.UUID
+	for {
+		md5hash.Sum(newid[:0])
+		if !newid.Equals(u) {
+			return newid
+		}
+		common.Must2(md5hash.Write([]byte("533eff8a-4113-4b10-b5ce-0f5d76b98cd2")))
+	}
+}
+
 func NewAlterIDs(primary *ID, alterIDCount uint16) []*ID {
 	alterIDs := make([]*ID, alterIDCount)
 	prevID := primary.UUID()
 	for idx := range alterIDs {
-		newid := prevID.Next()
+		newid := nextId(&prevID)
 		// TODO: check duplicates
 		alterIDs[idx] = NewID(newid)
 		prevID = newid

common/uuid/uuid.go

@@ -2,7 +2,6 @@ package uuid // import "v2ray.com/core/common/uuid"
 
 import (
 	"bytes"
-	"crypto/md5"
 	"crypto/rand"
 	"encoding/hex"
 
@@ -46,21 +45,6 @@ func (u *UUID) Equals(another *UUID) bool {
 	return bytes.Equal(u.Bytes(), another.Bytes())
 }
 
-// Next generates a deterministic random UUID based on this UUID.
-func (u *UUID) Next() UUID {
-	md5hash := md5.New()
-	common.Must2(md5hash.Write(u.Bytes()))
-	common.Must2(md5hash.Write([]byte("16167dc8-16b6-4e6d-b8bb-65dd68113a81")))
-	var newid UUID
-	for {
-		md5hash.Sum(newid[:0])
-		if !newid.Equals(u) {
-			return newid
-		}
-		common.Must2(md5hash.Write([]byte("533eff8a-4113-4b10-b5ce-0f5d76b98cd2")))
-	}
-}
-
 // New creates a UUID with random value.
 func New() UUID {
 	var uuid UUID