x/crypto/ssh: hide msgNewKeys in the transport layer.
This ensures that extraneous key exchanges cannot confuse application
level code.
Change-Id: I1a333e2b7b46f1e484406a79db7a949294e79c6d
Reviewed-on: https://go-review.googlesource.com/22417
Reviewed-by: Han-Wen Nienhuys <hanwen@google.com>
Run-TryBot: Han-Wen Nienhuys <hanwen@google.com>
Reviewed-by: Adam Langley <agl@golang.org>
diff --git a/ssh/handshake_test.go b/ssh/handshake_test.go
index ef97d57..da53d3a 100644
--- a/ssh/handshake_test.go
+++ b/ssh/handshake_test.go
@@ -104,7 +104,7 @@
}
if i == 5 {
// halfway through, we request a key change.
- _, _, err := trC.sendKexInit(subsequentKeyExchange)
+ err := trC.sendKexInit(subsequentKeyExchange)
if err != nil {
t.Fatalf("sendKexInit: %v", err)
}
@@ -161,7 +161,7 @@
}
// Now request a key change.
- _, _, err = trC.sendKexInit(subsequentKeyExchange)
+ err = trC.sendKexInit(subsequentKeyExchange)
if err != nil {
t.Errorf("sendKexInit: %v", err)
}
@@ -184,6 +184,28 @@
}
}
+func TestForceFirstKex(t *testing.T) {
+ checker := &testChecker{}
+ trC, trS, err := handshakePair(&ClientConfig{HostKeyCallback: checker.Check}, "addr")
+ if err != nil {
+ t.Fatalf("handshakePair: %v", err)
+ }
+
+ defer trC.Close()
+ defer trS.Close()
+
+ trC.writePacket(Marshal(&serviceRequestMsg{serviceUserAuth}))
+
+ // We setup the initial key exchange, but the remote side
+ // tries to send serviceRequestMsg in cleartext, which is
+ // disallowed.
+
+ err = trS.sendKexInit(firstKeyExchange)
+ if err == nil {
+ t.Errorf("server first kex init should reject unexpected packet")
+ }
+}
+
func TestHandshakeTwice(t *testing.T) {
checker := &testChecker{}
trC, trS, err := handshakePair(&ClientConfig{HostKeyCallback: checker.Check}, "addr")
@@ -194,18 +216,25 @@
defer trC.Close()
defer trS.Close()
+ // Both sides should ask for the first key exchange first.
+ err = trS.sendKexInit(firstKeyExchange)
+ if err != nil {
+ t.Errorf("server sendKexInit: %v", err)
+ }
+
+ err = trC.sendKexInit(firstKeyExchange)
+ if err != nil {
+ t.Errorf("client sendKexInit: %v", err)
+ }
+
+ sent := 0
// send a packet
packet := make([]byte, 5)
packet[0] = msgRequestSuccess
if err := trC.writePacket(packet); err != nil {
t.Errorf("writePacket: %v", err)
}
-
- // Now request a key change.
- _, _, err = trC.sendKexInit(subsequentKeyExchange)
- if err != nil {
- t.Errorf("sendKexInit: %v", err)
- }
+ sent++
// Send another packet. Use a fresh one, since writePacket destroys.
packet = make([]byte, 5)
@@ -213,9 +242,10 @@
if err := trC.writePacket(packet); err != nil {
t.Errorf("writePacket: %v", err)
}
+ sent++
// 2nd key change.
- _, _, err = trC.sendKexInit(subsequentKeyExchange)
+ err = trC.sendKexInit(subsequentKeyExchange)
if err != nil {
t.Errorf("sendKexInit: %v", err)
}
@@ -225,17 +255,15 @@
if err := trC.writePacket(packet); err != nil {
t.Errorf("writePacket: %v", err)
}
+ sent++
packet = make([]byte, 5)
packet[0] = msgRequestSuccess
- for i := 0; i < 5; i++ {
+ for i := 0; i < sent; i++ {
msg, err := trS.readPacket()
if err != nil {
t.Fatalf("server closed too soon: %v", err)
}
- if msg[0] == msgNewKeys {
- continue
- }
if bytes.Compare(msg, packet) != 0 {
t.Errorf("packet %d: got %q want %q", i, msg, packet)
