send: more precise padding calculation

This commit is contained in:
Jason A. Donenfeld 2018-09-16 23:42:31 +02:00
parent 47d1140361
commit 942abf948a

10
send.go
View file

@ -488,11 +488,13 @@ func (device *Device) RoutineEncryption() {
// pad content to multiple of 16 // pad content to multiple of 16
mtu := int(atomic.LoadInt32(&device.tun.mtu)) mtu := int(atomic.LoadInt32(&device.tun.mtu))
rem := len(elem.packet) % PaddingMultiple lastUnit := len(elem.packet) % mtu
if rem > 0 { paddedSize := (lastUnit + PaddingMultiple - 1) & ^(PaddingMultiple - 1)
for i := 0; i < PaddingMultiple-rem && len(elem.packet) < mtu; i++ { if paddedSize > mtu {
elem.packet = append(elem.packet, 0) paddedSize = mtu
} }
for i := len(elem.packet); i < paddedSize; i++ {
elem.packet = append(elem.packet, 0)
} }
// encrypt content and release to consumer // encrypt content and release to consumer