negotiate: minor NewServerContext cleanup

Explicitely returning the serverDone boolean allows for slightly cleaner code

negotiate/negotiate.go

@@ -334,23 +334,15 @@ type ServerContext struct {
 // credentials created by AcquireServerCredentials and token from
 // the client to start server Negotiate negotiation sequence.
 // It also returns new token to be sent to the client.
-func NewServerContext(cred *sspi.Credentials, token []byte) (sc *ServerContext, outputToken []byte, err error) {
+func NewServerContext(cred *sspi.Credentials, token []byte) (sc *ServerContext, authDone bool, outputToken []byte, err error) {
 	otoken := make([]byte, PackageInfo.MaxToken)
 	c := sspi.NewServerContext(cred, sspi.ASC_REQ_CONNECTION)
 	authDone, n, err2 := updateContext(c, otoken, token, nil)
 	if err2 != nil {
-		return nil, nil, err2
-	}
-	if authDone {
-		c.Release()
-		return nil, nil, errors.New("negotiate authentication should not be completed yet")
-	}
-	if n == 0 {
-		c.Release()
-		return nil, nil, errors.New("negotiate token should not be empty")
+		return nil, false, nil, err2
 	}
 	otoken = otoken[:n]
-	return &ServerContext{sctxt: c}, otoken, nil
+	return &ServerContext{sctxt: c}, authDone, otoken, nil
 }
 
 // Release free up resources associated with server context c.

negotiate/negotiate_test.go

@@ -71,15 +71,15 @@ func testNegotiate(t *testing.T, clientCred *sspi.Credentials, SPN string) {
 
 	testContextExpiry(t, "client security context", client)
 
-	server, toClientToken, err := negotiate.NewServerContext(serverCred, toServerToken)
+	server, serverDone, toClientToken, err := negotiate.NewServerContext(serverCred, toServerToken)
 	if err != nil {
 		t.Fatal(err)
 	}
 	defer server.Release()
 
 	testContextExpiry(t, "server security context", server)
 
-	var clientDone, serverDone bool
+	var clientDone bool
 	for {
 		if len(toClientToken) == 0 {
 			break
@@ -162,14 +162,14 @@ func TestNegotiateFailure(t *testing.T) {
 	}
 	t.Logf("sent %d bytes to server", len(toServerToken))
 
-	server, toClientToken, err := negotiate.NewServerContext(serverCred, toServerToken)
+	server, serverDone, toClientToken, err := negotiate.NewServerContext(serverCred, toServerToken)
 	if err != nil {
 		t.Fatal(err)
 	}
 	defer server.Release()
 
 	for {
-		var clientDone, serverDone bool
+		var clientDone bool
 		if len(toClientToken) == 0 {
 			t.Fatal("token for client cannot be empty")
 		}
@@ -242,13 +242,13 @@ func TestSignature(t *testing.T) {
 		t.Fatal("token for server cannot be empty")
 	}
 
-	server, toClientToken, err := negotiate.NewServerContext(serverCred, toServerToken)
+	server, serverDone, toClientToken, err := negotiate.NewServerContext(serverCred, toServerToken)
 	if err != nil {
 		t.Fatal(err)
 	}
 	defer server.Release()
 
-	var clientDone, serverDone bool
+	var clientDone bool
 	for {
 		if len(toClientToken) == 0 {
 			break