nebula/connection_state.go

97 lines
2.5 KiB
Go

package nebula
import (
"crypto/rand"
"encoding/json"
"fmt"
"sync"
"sync/atomic"
"github.com/flynn/noise"
"github.com/sirupsen/logrus"
"github.com/slackhq/nebula/cert"
"github.com/slackhq/nebula/noiseutil"
)
const ReplayWindow = 1024
type ConnectionState struct {
eKey *NebulaCipherState
dKey *NebulaCipherState
H *noise.HandshakeState
myCert cert.Certificate
peerCert *cert.CachedCertificate
initiator bool
messageCounter atomic.Uint64
window *Bits
writeLock sync.Mutex
}
func NewConnectionState(l *logrus.Logger, cs *CertState, crt cert.Certificate, initiator bool, pattern noise.HandshakePattern) (*ConnectionState, error) {
var dhFunc noise.DHFunc
switch crt.Curve() {
case cert.Curve_CURVE25519:
dhFunc = noise.DH25519
case cert.Curve_P256:
if cs.pkcs11Backed {
dhFunc = noiseutil.DHP256PKCS11
} else {
dhFunc = noiseutil.DHP256
}
default:
return nil, fmt.Errorf("invalid curve: %s", crt.Curve())
}
var ncs noise.CipherSuite
if cs.cipher == "chachapoly" {
ncs = noise.NewCipherSuite(dhFunc, noise.CipherChaChaPoly, noise.HashSHA256)
} else {
ncs = noise.NewCipherSuite(dhFunc, noiseutil.CipherAESGCM, noise.HashSHA256)
}
static := noise.DHKey{Private: cs.privateKey, Public: crt.PublicKey()}
b := NewBits(ReplayWindow)
// Clear out bit 0, we never transmit it, and we don't want it showing as packet loss
b.Update(l, 0)
hs, err := noise.NewHandshakeState(noise.Config{
CipherSuite: ncs,
Random: rand.Reader,
Pattern: pattern,
Initiator: initiator,
StaticKeypair: static,
//NOTE: These should come from CertState (pki.go) when we finally implement it
PresharedKey: []byte{},
PresharedKeyPlacement: 0,
})
if err != nil {
return nil, fmt.Errorf("NewConnectionState: %s", err)
}
// The queue and ready params prevent a counter race that would happen when
// sending stored packets and simultaneously accepting new traffic.
ci := &ConnectionState{
H: hs,
initiator: initiator,
window: b,
myCert: crt,
}
// always start the counter from 2, as packet 1 and packet 2 are handshake packets.
ci.messageCounter.Add(2)
return ci, nil
}
func (cs *ConnectionState) MarshalJSON() ([]byte, error) {
return json.Marshal(m{
"certificate": cs.peerCert,
"initiator": cs.initiator,
"message_counter": cs.messageCounter.Load(),
})
}
func (cs *ConnectionState) Curve() cert.Curve {
return cs.myCert.Curve()
}