package kcp import ( "hash/fnv" "github.com/v2ray/v2ray-core/common/alloc" "github.com/v2ray/v2ray-core/common/serial" "github.com/v2ray/v2ray-core/transport/internet" ) type SimpleAuthenticator struct{} func NewSimpleAuthenticator() internet.Authenticator { return &SimpleAuthenticator{} } func (this *SimpleAuthenticator) Overhead() int { return 6 } func (this *SimpleAuthenticator) Seal(buffer *alloc.Buffer) { buffer.PrependUint16(uint16(buffer.Len())) fnvHash := fnv.New32a() fnvHash.Write(buffer.Value) buffer.PrependHash(fnvHash) len := buffer.Len() xtra := 4 - len%4 if xtra != 0 { buffer.Slice(0, len+xtra) } xorfwd(buffer.Value) if xtra != 0 { buffer.Slice(0, len) } } func (this *SimpleAuthenticator) Open(buffer *alloc.Buffer) bool { len := buffer.Len() xtra := 4 - len%4 if xtra != 0 { buffer.Slice(0, len+xtra) } xorbkd(buffer.Value) if xtra != 0 { buffer.Slice(0, len) } fnvHash := fnv.New32a() fnvHash.Write(buffer.Value[4:]) if serial.BytesToUint32(buffer.Value[:4]) != fnvHash.Sum32() { return false } length := serial.BytesToUint16(buffer.Value[4:6]) if buffer.Len()-6 != int(length) { return false } buffer.SliceFrom(6) return true }