lib/connections: Validate device id before assuming success (fixes #5934) (#5935)

* lib/connections: Validate device id before assuming success (fixes #5934)

* Vet
This commit is contained in:
Audrius Butkevicius 2019-08-09 12:31:42 +01:00 committed by GitHub
parent 7b37d453f9
commit 58ef5368f8
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GPG Key ID: 4AEE18F83AFDEB23
6 changed files with 48 additions and 13 deletions

1
go.mod
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@ -46,7 +46,6 @@ require (
gopkg.in/asn1-ber.v1 v1.0.0-20170511165959-379148ca0225 // indirect
gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127 // indirect
gopkg.in/ldap.v2 v2.5.1
gopkg.in/yaml.v2 v2.2.2 // indirect
)
go 1.12

2
go.sum
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@ -5,6 +5,7 @@ github.com/AudriusButkevicius/pfilter v0.0.0-20190627213056-c55ef6137fc6/go.mod
github.com/AudriusButkevicius/recli v0.0.5 h1:xUa55PvWTHBm17T6RvjElRO3y5tALpdceH86vhzQ5wg=
github.com/AudriusButkevicius/recli v0.0.5/go.mod h1:Q2E26yc6RvWWEz/TJ/goUp6yXvipYdJI096hpoaqsNs=
github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03qcyfWMU=
github.com/StackExchange/wmi v0.0.0-20180116203802-5d049714c4a6 h1:fLjPD/aNc3UIOA6tDi6QXUemppXK3P9BI7mr2hd6gx8=
github.com/StackExchange/wmi v0.0.0-20180116203802-5d049714c4a6/go.mod h1:3eOhrUMpNV+6aFIbp5/iudMxNCF27Vw2OZgy4xEx0Fg=
github.com/alecthomas/template v0.0.0-20160405071501-a0175ee3bccc/go.mod h1:LOuyumcjzFXgccqObfd/Ljyb9UuFJ6TxHnclSeseNhc=
github.com/alecthomas/units v0.0.0-20151022065526-2efee857e7cf/go.mod h1:ybxpYRFXyAe+OPACYpWeL0wqObRcbAqCMya13uyzqw0=
@ -37,6 +38,7 @@ github.com/getsentry/raven-go v0.2.0 h1:no+xWJRb5ZI7eE8TWgIq1jLulQiIoLG0IfYxv5JY
github.com/getsentry/raven-go v0.2.0/go.mod h1:KungGk8q33+aIAZUIVWZDr2OfAEBsO49PX4NzFV5kcQ=
github.com/go-kit/kit v0.8.0/go.mod h1:xBxKIO96dXMWWy0MnWVtmwkA9/13aqxPnvrjFYMA2as=
github.com/go-logfmt/logfmt v0.3.0/go.mod h1:Qt1PoO58o5twSAckw1HlFXLmHsOX5/0LbT9GBnD5lWE=
github.com/go-ole/go-ole v1.2.1 h1:2lOsA72HgjxAuMlKpFiCbHTvu44PIVkZ5hqm3RSdI/E=
github.com/go-ole/go-ole v1.2.1/go.mod h1:7FAglXiTm7HKlQRDeOQ6ZNUHidzCWXuZWq/1dTyBNF8=
github.com/go-stack/stack v1.8.0/go.mod h1:v0f6uXyyMGvRgIKkXu+yp6POWl0qKG85gN/melR3HDY=
github.com/gobwas/glob v0.0.0-20170212200151-51eb1ee00b6d h1:IngNQgbqr5ZOU0exk395Szrvkzes9Ilk1fmJfkw7d+M=

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@ -36,7 +36,7 @@ type quicDialer struct {
tlsCfg *tls.Config
}
func (d *quicDialer) Dial(id protocol.DeviceID, uri *url.URL) (internalConn, error) {
func (d *quicDialer) Dial(_ protocol.DeviceID, uri *url.URL) (internalConn, error) {
uri = fixupPort(uri, config.DefaultQUICPort)
addr, err := net.ResolveUDPAddr("udp", uri.Host)

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@ -231,7 +231,7 @@ func (s *service) handle(stop chan struct{}) {
continue
}
c.SetDeadline(time.Now().Add(20 * time.Second))
_ = c.SetDeadline(time.Now().Add(20 * time.Second))
hello, err := protocol.ExchangeHello(c, s.model.GetHello(remoteID))
if err != nil {
if protocol.IsVersionMismatch(err) {
@ -255,7 +255,7 @@ func (s *service) handle(stop chan struct{}) {
c.Close()
continue
}
c.SetDeadline(time.Time{})
_ = c.SetDeadline(time.Time{})
// The Model will return an error for devices that we don't want to
// have a connection with for whatever reason, for example unknown devices.
@ -850,8 +850,15 @@ func (s *service) dialParallel(deviceID protocol.DeviceID, dialTargets []dialTar
wg.Add(1)
go func(tgt dialTarget) {
conn, err := tgt.Dial()
s.setConnectionStatus(tgt.addr, err)
if err == nil {
// Closes the connection on error
err = s.validateIdentity(conn, deviceID)
}
s.setConnectionStatus(tgt.addr, err)
if err != nil {
l.Debugln("dialing", deviceID, tgt.uri, "error:", err)
} else {
l.Debugln("dialing", deviceID, tgt.uri, "success:", conn)
res <- conn
}
wg.Done()
@ -884,3 +891,36 @@ func (s *service) dialParallel(deviceID protocol.DeviceID, dialTargets []dialTar
}
return internalConn{}, false
}
func (s *service) validateIdentity(c internalConn, expectedID protocol.DeviceID) error {
cs := c.ConnectionState()
// We should have received exactly one certificate from the other
// side. If we didn't, they don't have a device ID and we drop the
// connection.
certs := cs.PeerCertificates
if cl := len(certs); cl != 1 {
l.Infof("Got peer certificate list of length %d != 1 from peer at %s; protocol error", cl, c)
c.Close()
return fmt.Errorf("expected 1 certificate, got %d", cl)
}
remoteCert := certs[0]
remoteID := protocol.NewDeviceID(remoteCert.Raw)
// The device ID should not be that of ourselves. It can happen
// though, especially in the presence of NAT hairpinning, multiple
// clients between the same NAT gateway, and global discovery.
if remoteID == s.myID {
l.Infof("Connected to myself (%s) at %s - should not happen", remoteID, c)
c.Close()
return fmt.Errorf("connected to self")
}
// We should see the expected device ID
if !remoteID.Equals(expectedID) {
c.Close()
return fmt.Errorf("unexpected device id, expected %s got %s", expectedID, remoteID)
}
return nil
}

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@ -215,11 +215,5 @@ type dialTarget struct {
func (t dialTarget) Dial() (internalConn, error) {
l.Debugln("dialing", t.deviceID, t.uri, "prio", t.priority)
conn, err := t.dialer.Dial(t.deviceID, t.uri)
if err != nil {
l.Debugln("dialing", t.deviceID, t.uri, "error:", err)
} else {
l.Debugln("dialing", t.deviceID, t.uri, "success:", conn)
}
return conn, err
return t.dialer.Dial(t.deviceID, t.uri)
}

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@ -30,7 +30,7 @@ type tcpDialer struct {
tlsCfg *tls.Config
}
func (d *tcpDialer) Dial(id protocol.DeviceID, uri *url.URL) (internalConn, error) {
func (d *tcpDialer) Dial(_ protocol.DeviceID, uri *url.URL) (internalConn, error) {
uri = fixupPort(uri, config.DefaultTCPPort)
conn, err := dialer.DialTimeout(uri.Scheme, uri.Host, 10*time.Second)