Xray-core/common/uuid/uuid.go

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package uuid // import "github.com/xtls/xray-core/common/uuid"
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import (
"bytes"
"crypto/rand"
"crypto/sha1"
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"encoding/hex"
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"github.com/xtls/xray-core/common"
"github.com/xtls/xray-core/common/errors"
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)
var (
byteGroups = []int{8, 4, 4, 4, 12}
)
type UUID [16]byte
// String returns the string representation of this UUID.
func (u *UUID) String() string {
bytes := u.Bytes()
result := hex.EncodeToString(bytes[0 : byteGroups[0]/2])
start := byteGroups[0] / 2
for i := 1; i < len(byteGroups); i++ {
nBytes := byteGroups[i] / 2
result += "-"
result += hex.EncodeToString(bytes[start : start+nBytes])
start += nBytes
}
return result
}
// Bytes returns the bytes representation of this UUID.
func (u *UUID) Bytes() []byte {
return u[:]
}
// Equals returns true if this UUID equals another UUID by value.
func (u *UUID) Equals(another *UUID) bool {
if u == nil && another == nil {
return true
}
if u == nil || another == nil {
return false
}
return bytes.Equal(u.Bytes(), another.Bytes())
}
// New creates a UUID with random value.
func New() UUID {
var uuid UUID
common.Must2(rand.Read(uuid.Bytes()))
uuid[6] = (uuid[6] & 0x0f) | (4 << 4)
uuid[8] = (uuid[8]&(0xff>>2) | (0x02 << 6))
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return uuid
}
// ParseBytes converts a UUID in byte form to object.
func ParseBytes(b []byte) (UUID, error) {
var uuid UUID
if len(b) != 16 {
return uuid, errors.New("invalid UUID: ", b)
}
copy(uuid[:], b)
return uuid, nil
}
// ParseString converts a UUID in string form to object.
func ParseString(str string) (UUID, error) {
var uuid UUID
text := []byte(str)
if l := len(text); l < 32 || l > 36 {
if l == 0 || l > 30 {
return uuid, errors.New("invalid UUID: ", str)
}
h := sha1.New()
h.Write(uuid[:])
h.Write(text)
u := h.Sum(nil)[:16]
u[6] = (u[6] & 0x0f) | (5 << 4)
u[8] = (u[8]&(0xff>>2) | (0x02 << 6))
copy(uuid[:], u)
return uuid, nil
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}
b := uuid.Bytes()
for _, byteGroup := range byteGroups {
if text[0] == '-' {
text = text[1:]
}
if _, err := hex.Decode(b[:byteGroup/2], text[:byteGroup]); err != nil {
return uuid, err
}
text = text[byteGroup:]
b = b[byteGroup/2:]
}
return uuid, nil
}