github.com/v2fly/v2ray-core/v5@v5.16.2-0.20240507031116-8191faa6e095/common/protocol/id.go (about)

     1  package protocol
     2  
     3  import (
     4  	"crypto/hmac"
     5  	"crypto/md5"
     6  	"hash"
     7  
     8  	"github.com/v2fly/v2ray-core/v5/common"
     9  	"github.com/v2fly/v2ray-core/v5/common/uuid"
    10  )
    11  
    12  const (
    13  	IDBytesLen = 16
    14  )
    15  
    16  type IDHash func(key []byte) hash.Hash
    17  
    18  func DefaultIDHash(key []byte) hash.Hash {
    19  	return hmac.New(md5.New, key)
    20  }
    21  
    22  // The ID of en entity, in the form of a UUID.
    23  type ID struct {
    24  	uuid   uuid.UUID
    25  	cmdKey [IDBytesLen]byte
    26  }
    27  
    28  // Equals returns true if this ID equals to the other one.
    29  func (id *ID) Equals(another *ID) bool {
    30  	return id.uuid.Equals(&(another.uuid))
    31  }
    32  
    33  func (id *ID) Bytes() []byte {
    34  	return id.uuid.Bytes()
    35  }
    36  
    37  func (id *ID) String() string {
    38  	return id.uuid.String()
    39  }
    40  
    41  func (id *ID) UUID() uuid.UUID {
    42  	return id.uuid
    43  }
    44  
    45  func (id ID) CmdKey() []byte {
    46  	return id.cmdKey[:]
    47  }
    48  
    49  // NewID returns an ID with given UUID.
    50  func NewID(uuid uuid.UUID) *ID {
    51  	id := &ID{uuid: uuid}
    52  	md5hash := md5.New()
    53  	common.Must2(md5hash.Write(uuid.Bytes()))
    54  	common.Must2(md5hash.Write([]byte("c48619fe-8f02-49e0-b9e9-edf763e17e21")))
    55  	md5hash.Sum(id.cmdKey[:0])
    56  	return id
    57  }
    58  
    59  func nextID(u *uuid.UUID) uuid.UUID {
    60  	md5hash := md5.New()
    61  	common.Must2(md5hash.Write(u.Bytes()))
    62  	common.Must2(md5hash.Write([]byte("16167dc8-16b6-4e6d-b8bb-65dd68113a81")))
    63  	var newid uuid.UUID
    64  	for {
    65  		md5hash.Sum(newid[:0])
    66  		if !newid.Equals(u) {
    67  			return newid
    68  		}
    69  		common.Must2(md5hash.Write([]byte("533eff8a-4113-4b10-b5ce-0f5d76b98cd2")))
    70  	}
    71  }
    72  
    73  func NewAlterIDs(primary *ID, alterIDCount uint16) []*ID {
    74  	alterIDs := make([]*ID, alterIDCount)
    75  	prevID := primary.UUID()
    76  	for idx := range alterIDs {
    77  		newid := nextID(&prevID)
    78  		alterIDs[idx] = NewID(newid)
    79  		prevID = newid
    80  	}
    81  	return alterIDs
    82  }