toni/baalvpn
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

use crypto/hpke for MLKEM768X25519

Browse Source
This commit is contained in:
Antoni Piasecki
2026-07-22 16:05:30 +02:00
parent a2d647f3af
commit f9f0df478d
6 changed files with 86 additions and 46 deletions
Download Patch File Download Diff File Expand all files Collapse all files

95
client/main.go
View File

@@ -1,7 +1,7 @@
package main
import (
"crypto/sha256"
"crypto/hpke"
"encoding/binary"
"encoding/hex"
"log"
@@ -13,7 +13,6 @@ import (
"baalvpn/shared"
"filippo.io/mlkem768/xwing"
"github.com/songgao/water"
)
@@ -27,10 +26,10 @@ var (
serverAddr *net.UDPAddr
iface *water.Interface
conn *net.UDPConn
privKey *xwing.DecapsulationKey
privKey hpke.PrivateKey
establishMutex sync.Mutex
peerPubKeys = shared.NewTMap[string, []byte]()
peerPubKeys = shared.NewTMap[string, hpke.PublicKey]()
peerSessionKeys = shared.NewTMap[string, []byte]()
peerEstablishAcks = shared.NewTMap[string, bool]()
)
@@ -63,13 +62,14 @@ func main() {
func register() {
var err error
privKey, err = xwing.GenerateKey()
privKey, err = hpke.MLKEM768X25519().GenerateKey()
if err != nil {
panic(err)
}
pubKey := privKey.EncapsulationKey()
pubKey := privKey.PublicKey()
req := shared.BuildPkt(shared.REQ_REGISTER, pubKey)
req := shared.BuildPkt(shared.REQ_REGISTER, pubKey.Bytes())
if _, err := conn.WriteToUDP(req, serverAddr); err != nil {
panic(err)
}
@@ -88,42 +88,47 @@ func getOrEstablishSessionKey(ip string) []byte {
return key
}
log.Println("requesting pubkey of " + ip)
req := shared.BuildPkt(shared.REQ_GET_PUBKEY, net.ParseIP(ip))
if _, err := conn.WriteToUDP(req, serverAddr); err != nil {
panic(err)
}
// TODO: this definitely shouldnt block the main thread
for {
// TODO: eww
// request pubkey every 50ms
time.Sleep(50 * time.Millisecond)
if peerPubKey, ok := peerPubKeys.GetOK(ip); ok {
log.Println("got pubkey of " + ip)
ciphertext, sharedSecret, err := xwing.Encapsulate(peerPubKey)
if err != nil {
panic(err)
}
reqData := append(net.ParseIP(ip), append(internalIP, ciphertext...)...)
req := shared.BuildPkt(shared.REQ_ESTABLISH, reqData)
peerPubKey, ok := peerPubKeys.GetOK(ip)
if !ok {
req := shared.BuildPkt(shared.REQ_GET_PUBKEY, net.ParseIP(ip))
if _, err := conn.WriteToUDP(req, serverAddr); err != nil {
panic(err)
}
for {
// TODO: eww
time.Sleep(50 * time.Millisecond)
if peerEstablishAcks.Get(ip) {
peerEstablishAcks.Delete(ip)
break
}
}
sessionKey := sha256.Sum256(sharedSecret)
peerSessionKeys.Set(ip, sessionKey[:])
return sessionKey[:]
continue
}
log.Println("got pubkey of " + ip)
ciphertext, sender, err := hpke.NewSender(peerPubKey, hpke.HKDFSHA256(), hpke.ExportOnly(), nil)
if err != nil {
panic(err)
}
sessionKey, err := sender.Export("baalvpn", 32)
if err != nil {
panic(err)
}
reqData := append(net.ParseIP(ip), append(internalIP, ciphertext...)...)
req := shared.BuildPkt(shared.REQ_ESTABLISH, reqData)
if _, err := conn.WriteToUDP(req, serverAddr); err != nil {
panic(err)
}
for {
// TODO: eww
time.Sleep(50 * time.Millisecond)
if peerEstablishAcks.Get(ip) {
peerEstablishAcks.Delete(ip)
break
}
}
peerSessionKeys.Set(ip, sessionKey)
return sessionKey
}
}
@@ -193,21 +198,27 @@ func handlePkt(pkt []byte) {
}
case shared.RESP_GET_PUBKEY:
respIP := net.IP(pkt[4:20]).String()
pubKey := pkt[20:]
pubKey, err := hpke.MLKEM768X25519().NewPublicKey(pkt[20:])
if err != nil {
panic(err)
}
peerPubKeys.Set(respIP, pubKey)
case shared.REQ_ESTABLISH:
srcIP := net.IP(pkt[20:36]).String()
ciphertext := pkt[36:]
sharedSecret, err := xwing.Decapsulate(privKey, ciphertext)
r, err := hpke.NewRecipient(ciphertext, privKey, hpke.HKDFSHA256(), hpke.ExportOnly(), nil)
if err != nil {
panic(err)
}
sessionKey, err := r.Export("baalvpn", 32)
if err != nil {
panic(err)
}
sessionKey := sha256.Sum256(sharedSecret)
peerSessionKeys.Set(srcIP, sessionKey[:])
log.Println("received session key from", srcIP)
peerSessionKeys.Set(srcIP, sessionKey)
reqData := append(net.ParseIP(srcIP), internalIP...)
req := shared.BuildPkt(shared.RESP_ESTABLISH, reqData)
if _, err := conn.WriteToUDP(req, serverAddr); err != nil {