v1.0.0

common/protocol/id.go

@@ -0,0 +1,82 @@
+package protocol
+
+import (
+	"crypto/hmac"
+	"crypto/md5"
+	"hash"
+
+	"github.com/xtls/xray-core/v1/common"
+	"github.com/xtls/xray-core/v1/common/uuid"
+)
+
+const (
+	IDBytesLen = 16
+)
+
+type IDHash func(key []byte) hash.Hash
+
+func DefaultIDHash(key []byte) hash.Hash {
+	return hmac.New(md5.New, key)
+}
+
+// The ID of en entity, in the form of a UUID.
+type ID struct {
+	uuid   uuid.UUID
+	cmdKey [IDBytesLen]byte
+}
+
+// Equals returns true if this ID equals to the other one.
+func (id *ID) Equals(another *ID) bool {
+	return id.uuid.Equals(&(another.uuid))
+}
+
+func (id *ID) Bytes() []byte {
+	return id.uuid.Bytes()
+}
+
+func (id *ID) String() string {
+	return id.uuid.String()
+}
+
+func (id *ID) UUID() uuid.UUID {
+	return id.uuid
+}
+
+func (id ID) CmdKey() []byte {
+	return id.cmdKey[:]
+}
+
+// NewID returns an ID with given UUID.
+func NewID(uuid uuid.UUID) *ID {
+	id := &ID{uuid: uuid}
+	md5hash := md5.New()
+	common.Must2(md5hash.Write(uuid.Bytes()))
+	common.Must2(md5hash.Write([]byte("c48619fe-8f02-49e0-b9e9-edf763e17e21")))
+	md5hash.Sum(id.cmdKey[:0])
+	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 := nextID(&prevID)
+		alterIDs[idx] = NewID(newid)
+		prevID = newid
+	}
+	return alterIDs
+}