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mirror of https://github.com/v2fly/v2ray-core.git synced 2024-12-22 18:17:52 -05:00
v2fly/transport/internet/kcp/crypt.go
2016-11-27 21:39:09 +01:00

64 lines
1.1 KiB
Go

package kcp
import (
"hash/fnv"
"v2ray.com/core/common/alloc"
"v2ray.com/core/common/serial"
"v2ray.com/core/transport/internet"
)
type SimpleAuthenticator struct{}
func NewSimpleAuthenticator() internet.Authenticator {
return &SimpleAuthenticator{}
}
func (v *SimpleAuthenticator) Overhead() int {
return 6
}
func (v *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 (v *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
}