mihomo/transport/vless/vision/padding.go
2025-08-21 19:37:26 +08:00

58 lines
1.4 KiB
Go

package vision
import (
"bytes"
"encoding/binary"
"github.com/metacubex/mihomo/common/buf"
"github.com/metacubex/mihomo/log"
"github.com/gofrs/uuid/v5"
"github.com/metacubex/randv2"
)
const (
PaddingHeaderLen = uuid.Size + 1 + 2 + 2 // =21
commandPaddingContinue byte = 0x00
commandPaddingEnd byte = 0x01
commandPaddingDirect byte = 0x02
)
func ApplyPadding(buffer *buf.Buffer, command byte, userUUID *uuid.UUID, paddingTLS bool) {
contentLen := int32(buffer.Len())
var paddingLen int32
if contentLen < 900 {
if paddingTLS {
//log.Debugln("long padding")
paddingLen = randv2.Int32N(500) + 900 - contentLen
} else {
paddingLen = randv2.Int32N(256)
}
}
binary.BigEndian.PutUint16(buffer.ExtendHeader(2), uint16(paddingLen))
binary.BigEndian.PutUint16(buffer.ExtendHeader(2), uint16(contentLen))
buffer.ExtendHeader(1)[0] = command
if userUUID != nil {
copy(buffer.ExtendHeader(uuid.Size), userUUID.Bytes())
}
buffer.Extend(int(paddingLen))
log.Debugln("XTLS Vision write padding: command=%d, payloadLen=%d, paddingLen=%d", command, contentLen, paddingLen)
}
func ReshapeBuffer(buffer *buf.Buffer) *buf.Buffer {
if buffer.Len() <= buf.BufferSize-PaddingHeaderLen {
return nil
}
cutAt := bytes.LastIndex(buffer.Bytes(), tlsApplicationDataStart)
if cutAt == -1 {
cutAt = buf.BufferSize / 2
}
buffer2 := buf.New()
buffer2.Write(buffer.From(cutAt))
buffer.Truncate(cutAt)
return buffer2
}