vppn/node/crypto.go
2024-12-18 14:40:25 +01:00

51 lines
1.1 KiB
Go

package node
import (
"sync"
"vppn/fasttime"
"golang.org/x/crypto/nacl/box"
)
// Encrypting the packet will also set the header's DataSize field.
func encryptPacket(h *header, sharedKey, data, out []byte) []byte {
out = out[:headerSize]
h.Marshal(out)
b := box.SealAfterPrecomputation(out[headerSize:headerSize], data, (*[24]byte)(out[:headerSize]), (*[32]byte)(sharedKey))
return out[:len(b)+headerSize]
}
func decryptPacket(sharedKey, packetAndHeader, out []byte) (decrypted []byte, ok bool) {
return box.OpenAfterPrecomputation(
out[:0],
packetAndHeader[headerSize:],
(*[24]byte)(packetAndHeader[:headerSize]),
(*[32]byte)(sharedKey))
}
func computeSharedKey(peerPubKey, privKey []byte) []byte {
shared := [32]byte{}
box.Precompute(&shared, (*[32]byte)(peerPubKey), (*[32]byte)(privKey))
return shared[:]
}
var (
traceIDLock sync.Mutex
traceIDTime uint64
traceIDCounter uint64
)
func newTraceID() (id uint64) {
traceIDLock.Lock()
defer traceIDLock.Unlock()
now := uint64(fasttime.Now())
if traceIDTime < now {
traceIDTime = now
traceIDCounter = 0
}
traceIDCounter++
return traceIDTime<<30 + traceIDCounter
}