nebula/handshake_ix.go

364 lines
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2019-11-19 18:00:20 +01:00
package nebula
import (
"sync/atomic"
"time"
"bytes"
"github.com/flynn/noise"
"github.com/golang/protobuf/proto"
)
// NOISE IX Handshakes
// This function constructs a handshake packet, but does not actually send it
// Sending is done by the handshake manager
func ixHandshakeStage0(f *Interface, vpnIp uint32, hostinfo *HostInfo) {
// This queries the lighthouse if we don't know a remote for the host
if hostinfo.remote == nil {
ips, err := f.lightHouse.Query(vpnIp, f)
if err != nil {
//l.Debugln(err)
}
for _, ip := range ips {
hostinfo.AddRemote(ip)
}
}
myIndex, err := generateIndex()
if err != nil {
l.WithError(err).WithField("vpnIp", IntIp(vpnIp)).
WithField("handshake", m{"stage": 0, "style": "ix_psk0"}).Error("Failed to generate index")
return
}
ci := hostinfo.ConnectionState
f.handshakeManager.AddIndexHostInfo(myIndex, hostinfo)
hsProto := &NebulaHandshakeDetails{
InitiatorIndex: myIndex,
Time: uint64(time.Now().Unix()),
Cert: ci.certState.rawCertificateNoKey,
}
hsBytes := []byte{}
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hs := &NebulaHandshake{
Details: hsProto,
}
hsBytes, err = proto.Marshal(hs)
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if err != nil {
l.WithError(err).WithField("vpnIp", IntIp(vpnIp)).
WithField("handshake", m{"stage": 0, "style": "ix_psk0"}).Error("Failed to marshal handshake message")
return
}
header := HeaderEncode(make([]byte, HeaderLen), Version, uint8(handshake), handshakeIXPSK0, 0, 1)
atomic.AddUint64(ci.messageCounter, 1)
msg, _, _, err := ci.H.WriteMessage(header, hsBytes)
if err != nil {
l.WithError(err).WithField("vpnIp", IntIp(vpnIp)).
WithField("handshake", m{"stage": 0, "style": "ix_psk0"}).Error("Failed to call noise.WriteMessage")
return
}
hostinfo.HandshakePacket[0] = msg
hostinfo.HandshakeReady = true
hostinfo.handshakeStart = time.Now()
}
func ixHandshakeStage1(f *Interface, addr *udpAddr, hostinfo *HostInfo, packet []byte, h *Header) bool {
var ip uint32
if h.RemoteIndex == 0 {
ci := f.newConnectionState(false, noise.HandshakeIX, []byte{}, 0)
// Mark packet 1 as seen so it doesn't show up as missed
ci.window.Update(1)
msg, _, _, err := ci.H.ReadMessage(nil, packet[HeaderLen:])
if err != nil {
l.WithError(err).WithField("udpAddr", addr).
WithField("handshake", m{"stage": 1, "style": "ix_psk0"}).Error("Failed to call noise.ReadMessage")
return true
}
hs := &NebulaHandshake{}
err = proto.Unmarshal(msg, hs)
/*
l.Debugln("GOT INDEX: ", hs.Details.InitiatorIndex)
*/
if err != nil || hs.Details == nil {
l.WithError(err).WithField("udpAddr", addr).
WithField("handshake", m{"stage": 1, "style": "ix_psk0"}).Error("Failed unmarshal handshake message")
return true
}
hostinfo, _ := f.handshakeManager.pendingHostMap.QueryReverseIndex(hs.Details.InitiatorIndex)
if hostinfo != nil && bytes.Equal(hostinfo.HandshakePacket[0], packet[HeaderLen:]) {
if msg, ok := hostinfo.HandshakePacket[2]; ok {
f.messageMetrics.Tx(handshake, NebulaMessageSubType(msg[1]), 1)
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err := f.outside.WriteTo(msg, addr)
if err != nil {
l.WithField("vpnIp", IntIp(hostinfo.hostId)).WithField("udpAddr", addr).
WithField("handshake", m{"stage": 2, "style": "ix_psk0"}).WithField("cached", true).
WithError(err).Error("Failed to send handshake message")
} else {
l.WithField("vpnIp", IntIp(hostinfo.hostId)).WithField("udpAddr", addr).
WithField("handshake", m{"stage": 2, "style": "ix_psk0"}).WithField("cached", true).
Info("Handshake message sent")
}
return false
}
l.WithField("vpnIp", IntIp(hostinfo.hostId)).WithField("udpAddr", addr).
WithField("handshake", m{"stage": 1, "style": "ix_psk0"}).WithField("cached", true).
WithField("packets", hostinfo.HandshakePacket).
Error("Seen this handshake packet already but don't have a cached packet to return")
}
remoteCert, err := RecombineCertAndValidate(ci.H, hs.Details.Cert)
if err != nil {
l.WithError(err).WithField("udpAddr", addr).
WithField("handshake", m{"stage": 1, "style": "ix_psk0"}).WithField("cert", remoteCert).
Info("Invalid certificate from host")
return true
}
vpnIP := ip2int(remoteCert.Details.Ips[0].IP)
certName := remoteCert.Details.Name
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myIndex, err := generateIndex()
if err != nil {
l.WithError(err).WithField("vpnIp", IntIp(vpnIP)).WithField("udpAddr", addr).
WithField("certName", certName).
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WithField("handshake", m{"stage": 1, "style": "ix_psk0"}).Error("Failed to generate index")
return true
}
hostinfo, err = f.handshakeManager.AddIndex(myIndex, ci)
if err != nil {
l.WithError(err).WithField("vpnIp", IntIp(vpnIP)).WithField("udpAddr", addr).
WithField("certName", certName).
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WithField("handshake", m{"stage": 1, "style": "ix_psk0"}).Error("Error adding index to connection manager")
return true
}
l.WithField("vpnIp", IntIp(vpnIP)).WithField("udpAddr", addr).
WithField("certName", certName).
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WithField("initiatorIndex", hs.Details.InitiatorIndex).WithField("responderIndex", hs.Details.ResponderIndex).
WithField("remoteIndex", h.RemoteIndex).WithField("handshake", m{"stage": 1, "style": "ix_psk0"}).
Info("Handshake message received")
hostinfo.remoteIndexId = hs.Details.InitiatorIndex
hs.Details.ResponderIndex = myIndex
hs.Details.Cert = ci.certState.rawCertificateNoKey
hsBytes, err := proto.Marshal(hs)
if err != nil {
l.WithError(err).WithField("vpnIp", IntIp(hostinfo.hostId)).WithField("udpAddr", addr).
WithField("certName", certName).
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WithField("handshake", m{"stage": 1, "style": "ix_psk0"}).Error("Failed to marshal handshake message")
return true
}
header := HeaderEncode(make([]byte, HeaderLen), Version, uint8(handshake), handshakeIXPSK0, hs.Details.InitiatorIndex, 2)
msg, dKey, eKey, err := ci.H.WriteMessage(header, hsBytes)
if err != nil {
l.WithError(err).WithField("vpnIp", IntIp(hostinfo.hostId)).WithField("udpAddr", addr).
WithField("certName", certName).
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WithField("handshake", m{"stage": 1, "style": "ix_psk0"}).Error("Failed to call noise.WriteMessage")
return true
}
if f.hostMap.CheckHandshakeCompleteIP(vpnIP) && vpnIP < ip2int(f.certState.certificate.Details.Ips[0].IP) {
l.WithField("vpnIp", IntIp(vpnIP)).WithField("udpAddr", addr).
WithField("certName", certName).
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WithField("initiatorIndex", hs.Details.InitiatorIndex).WithField("responderIndex", hs.Details.ResponderIndex).
WithField("remoteIndex", h.RemoteIndex).WithField("handshake", m{"stage": 1, "style": "ix_psk0"}).
Info("Prevented a handshake race")
// Send a test packet to trigger an authenticated tunnel test, this should suss out any lingering tunnel issues
f.SendMessageToVpnIp(test, testRequest, vpnIP, []byte(""), make([]byte, 12, 12), make([]byte, mtu))
return true
}
hostinfo.HandshakePacket[0] = make([]byte, len(packet[HeaderLen:]))
copy(hostinfo.HandshakePacket[0], packet[HeaderLen:])
// Regardless of whether you are the sender or receiver, you should arrive here
// and complete standing up the connection.
if dKey != nil && eKey != nil {
hostinfo.HandshakePacket[2] = make([]byte, len(msg))
copy(hostinfo.HandshakePacket[2], msg)
f.messageMetrics.Tx(handshake, NebulaMessageSubType(msg[1]), 1)
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err := f.outside.WriteTo(msg, addr)
if err != nil {
l.WithField("vpnIp", IntIp(vpnIP)).WithField("udpAddr", addr).
WithField("certName", certName).
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WithField("initiatorIndex", hs.Details.InitiatorIndex).WithField("responderIndex", hs.Details.ResponderIndex).
WithField("remoteIndex", h.RemoteIndex).WithField("handshake", m{"stage": 2, "style": "ix_psk0"}).
WithError(err).Error("Failed to send handshake")
} else {
l.WithField("vpnIp", IntIp(vpnIP)).WithField("udpAddr", addr).
WithField("certName", certName).
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WithField("initiatorIndex", hs.Details.InitiatorIndex).WithField("responderIndex", hs.Details.ResponderIndex).
WithField("remoteIndex", h.RemoteIndex).WithField("handshake", m{"stage": 2, "style": "ix_psk0"}).
Info("Handshake message sent")
}
ip = ip2int(remoteCert.Details.Ips[0].IP)
ci.peerCert = remoteCert
ci.dKey = NewNebulaCipherState(dKey)
ci.eKey = NewNebulaCipherState(eKey)
//l.Debugln("got symmetric pairs")
//hostinfo.ClearRemotes()
hostinfo.AddRemote(*addr)
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hostinfo.CreateRemoteCIDR(remoteCert)
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f.lightHouse.AddRemoteAndReset(ip, addr)
if f.serveDns {
dnsR.Add(remoteCert.Details.Name+".", remoteCert.Details.Ips[0].IP.String())
}
ho, err := f.hostMap.QueryVpnIP(vpnIP)
if err == nil && ho.localIndexId != 0 {
l.WithField("vpnIp", vpnIP).
WithField("certName", certName).
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WithField("action", "removing stale index").
WithField("index", ho.localIndexId).
Debug("Handshake processing")
f.hostMap.DeleteIndex(ho.localIndexId)
}
f.hostMap.AddIndexHostInfo(hostinfo.localIndexId, hostinfo)
f.hostMap.AddVpnIPHostInfo(vpnIP, hostinfo)
hostinfo.handshakeComplete()
} else {
l.WithField("vpnIp", IntIp(hostinfo.hostId)).WithField("udpAddr", addr).
WithField("certName", certName).
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WithField("handshake", m{"stage": 1, "style": "ix_psk0"}).
Error("Noise did not arrive at a key")
return true
}
}
f.hostMap.AddRemote(ip, addr)
return false
}
func ixHandshakeStage2(f *Interface, addr *udpAddr, hostinfo *HostInfo, packet []byte, h *Header) bool {
if hostinfo == nil {
return true
}
if bytes.Equal(hostinfo.HandshakePacket[2], packet[HeaderLen:]) {
l.WithField("vpnIp", IntIp(hostinfo.hostId)).WithField("udpAddr", addr).
WithField("handshake", m{"stage": 2, "style": "ix_psk0"}).WithField("header", h).
Error("Already seen this handshake packet")
return false
}
ci := hostinfo.ConnectionState
// Mark packet 2 as seen so it doesn't show up as missed
ci.window.Update(2)
hostinfo.HandshakePacket[2] = make([]byte, len(packet[HeaderLen:]))
copy(hostinfo.HandshakePacket[2], packet[HeaderLen:])
msg, eKey, dKey, err := ci.H.ReadMessage(nil, packet[HeaderLen:])
if err != nil {
l.WithError(err).WithField("vpnIp", IntIp(hostinfo.hostId)).WithField("udpAddr", addr).
WithField("handshake", m{"stage": 2, "style": "ix_psk0"}).WithField("header", h).
Error("Failed to call noise.ReadMessage")
// We don't want to tear down the connection on a bad ReadMessage because it could be an attacker trying
// to DOS us. Every other error condition after should to allow a possible good handshake to complete in the
// near future
return false
}
hs := &NebulaHandshake{}
err = proto.Unmarshal(msg, hs)
if err != nil || hs.Details == nil {
l.WithError(err).WithField("vpnIp", IntIp(hostinfo.hostId)).WithField("udpAddr", addr).
WithField("handshake", m{"stage": 2, "style": "ix_psk0"}).Error("Failed unmarshal handshake message")
return true
}
remoteCert, err := RecombineCertAndValidate(ci.H, hs.Details.Cert)
if err != nil {
l.WithError(err).WithField("vpnIp", IntIp(hostinfo.hostId)).WithField("udpAddr", addr).
WithField("cert", remoteCert).WithField("handshake", m{"stage": 2, "style": "ix_psk0"}).
Error("Invalid certificate from host")
return true
}
vpnIP := ip2int(remoteCert.Details.Ips[0].IP)
certName := remoteCert.Details.Name
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duration := time.Since(hostinfo.handshakeStart).Nanoseconds()
l.WithField("vpnIp", IntIp(vpnIP)).WithField("udpAddr", addr).
WithField("certName", certName).
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WithField("initiatorIndex", hs.Details.InitiatorIndex).WithField("responderIndex", hs.Details.ResponderIndex).
WithField("remoteIndex", h.RemoteIndex).WithField("handshake", m{"stage": 2, "style": "ix_psk0"}).
WithField("durationNs", duration).
Info("Handshake message received")
//ci.remoteIndex = hs.ResponderIndex
hostinfo.remoteIndexId = hs.Details.ResponderIndex
hs.Details.Cert = ci.certState.rawCertificateNoKey
/*
hsBytes, err := proto.Marshal(hs)
if err != nil {
l.Debugln("Failed to marshal handshake: ", err)
return
}
*/
// Regardless of whether you are the sender or receiver, you should arrive here
// and complete standing up the connection.
if dKey != nil && eKey != nil {
ip := ip2int(remoteCert.Details.Ips[0].IP)
ci.peerCert = remoteCert
ci.dKey = NewNebulaCipherState(dKey)
ci.eKey = NewNebulaCipherState(eKey)
//l.Debugln("got symmetric pairs")
//hostinfo.ClearRemotes()
f.hostMap.AddRemote(ip, addr)
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hostinfo.CreateRemoteCIDR(remoteCert)
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f.lightHouse.AddRemoteAndReset(ip, addr)
if f.serveDns {
dnsR.Add(remoteCert.Details.Name+".", remoteCert.Details.Ips[0].IP.String())
}
ho, err := f.hostMap.QueryVpnIP(vpnIP)
if err == nil && ho.localIndexId != 0 {
l.WithField("vpnIp", vpnIP).
WithField("certName", certName).
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WithField("action", "removing stale index").
WithField("index", ho.localIndexId).
Debug("Handshake processing")
f.hostMap.DeleteIndex(ho.localIndexId)
}
f.hostMap.AddVpnIPHostInfo(vpnIP, hostinfo)
f.hostMap.AddIndexHostInfo(hostinfo.localIndexId, hostinfo)
hostinfo.handshakeComplete()
f.metricHandshakes.Update(duration)
} else {
l.WithField("vpnIp", IntIp(hostinfo.hostId)).WithField("udpAddr", addr).
WithField("certName", certName).
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WithField("handshake", m{"stage": 2, "style": "ix_psk0"}).
Error("Noise did not arrive at a key")
return true
}
return false
}