ssh/agent: Fix error returned from agent responses that are too big.
Make sure a meaningful error is returned when the SSH agent client receives
a response that is too big.
Change-Id: Ied68b2c559a61dede2f3112c4c8143babd385f48
GitHub-Last-Rev: ad65e1b423bb00f2501dfde84040469aef4ee2df
GitHub-Pull-Request: golang/crypto#61
Reviewed-on: https://go-review.googlesource.com/c/143058
Reviewed-by: Han-Wen Nienhuys <hanwen@google.com>
Run-TryBot: Han-Wen Nienhuys <hanwen@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
diff --git a/ssh/agent/client.go b/ssh/agent/client.go
index 1934950..51f7405 100644
--- a/ssh/agent/client.go
+++ b/ssh/agent/client.go
@@ -348,7 +348,7 @@
}
respSize := binary.BigEndian.Uint32(respSizeBuf[:])
if respSize > maxAgentResponseBytes {
- return nil, clientErr(err)
+ return nil, clientErr(errors.New("response too large"))
}
buf := make([]byte, respSize)
diff --git a/ssh/agent/client_test.go b/ssh/agent/client_test.go
index e8cd978..2f798f9 100644
--- a/ssh/agent/client_test.go
+++ b/ssh/agent/client_test.go
@@ -241,6 +241,35 @@
return c1, c2, nil
}
+func TestServerResponseTooLarge(t *testing.T) {
+ a, b, err := netPipe()
+ if err != nil {
+ t.Fatalf("netPipe: %v", err)
+ }
+
+ defer a.Close()
+ defer b.Close()
+
+ var response identitiesAnswerAgentMsg
+ response.NumKeys = 1
+ response.Keys = make([]byte, maxAgentResponseBytes+1)
+
+ agent := NewClient(a)
+ go func() {
+ n, _ := b.Write(ssh.Marshal(response))
+ if n < 4 {
+ t.Fatalf("At least 4 bytes (the response size) should have been successfully written: %d < 4", n)
+ }
+ }()
+ _, err = agent.List()
+ if err == nil {
+ t.Fatal("Did not get error result")
+ }
+ if err.Error() != "agent: client error: response too large" {
+ t.Fatal("Did not get expected error result")
+ }
+}
+
func TestAuth(t *testing.T) {
agent, _, cleanup := startOpenSSHAgent(t)
defer cleanup()
