wgengine/magicsock: fix looksLikeInitiationMsg endianness (#16771)

WireGuard message type is little-endian encoded.

Updates tailscale/corp#30903

Signed-off-by: Jordan Whited <jordan@tailscale.com>
This commit is contained in:
Jordan Whited 2025-08-04 14:21:32 -07:00 committed by GitHub
parent 834630fedf
commit b0018f1e7d
No known key found for this signature in database
GPG Key ID: B5690EEEBB952194
2 changed files with 14 additions and 9 deletions

View File

@ -1765,11 +1765,8 @@ func (c *Conn) mkReceiveFunc(ruc *RebindingUDPConn, healthItem *health.ReceiveFu
// looksLikeInitiationMsg returns true if b looks like a WireGuard initiation
// message, otherwise it returns false.
func looksLikeInitiationMsg(b []byte) bool {
if len(b) == device.MessageInitiationSize &&
binary.BigEndian.Uint32(b) == device.MessageInitiationType {
return true
}
return false
return len(b) == device.MessageInitiationSize &&
binary.LittleEndian.Uint32(b) == device.MessageInitiationType
}
// receiveIP is the shared bits of ReceiveIPv4 and ReceiveIPv6.

View File

@ -9,6 +9,7 @@
crand "crypto/rand"
"crypto/tls"
"encoding/binary"
"encoding/hex"
"errors"
"fmt"
"io"
@ -3390,10 +3391,17 @@ func Test_virtualNetworkID(t *testing.T) {
}
func Test_looksLikeInitiationMsg(t *testing.T) {
initMsg := make([]byte, device.MessageInitiationSize)
binary.BigEndian.PutUint32(initMsg, device.MessageInitiationType)
initMsgSizeTransportType := make([]byte, device.MessageInitiationSize)
binary.BigEndian.PutUint32(initMsgSizeTransportType, device.MessageTransportType)
// initMsg was captured as the first packet from a WireGuard "session"
initMsg, err := hex.DecodeString("01000000d9205f67915a500e377b409e0c3d97ca91e68654b95952de965e75df491000cce00632678cd9e8c8525556aa8daf24e6cfc44c48812bb560ff3c1c5dee061b3f833dfaa48acf13b64bd1e0027aa4d977a3721b82fd6072338702fc3193651404980ad46dae2869ba6416cc0eb38621a4140b5b918eb6402b697202adb3002a6d00000000000000000000000000000000")
if err != nil {
t.Fatal(err)
}
if len(initMsg) != device.MessageInitiationSize {
t.Fatalf("initMsg is not %d bytes long", device.MessageInitiationSize)
}
initMsgSizeTransportType := make([]byte, len(initMsg))
copy(initMsgSizeTransportType, initMsg)
binary.LittleEndian.PutUint32(initMsgSizeTransportType, device.MessageTransportType)
tests := []struct {
name string
b []byte