fix: set session to DONE after next session URL has been retrieved

The presence of a next session URL in the session status message informs the frontend that there is a next session, so that it should not yet tell the user the session has finished. Previously the session status was set to DONE before the next session URL was retrieved. When SSE is used and the session status changes, the frontend is notified of this almost immediately. Thus in this case, it did not receive the next session URL, considering the session (chain) finished.

server/irmaserver/handle.go

@@ -115,15 +115,12 @@ func (session *session) handlePostSignature(signature *irma.SignedMessage) (*irm
 	request.Disclose = append(request.Disclose, session.implicitDisclosure...)
 
 	session.result.Disclosed, session.result.ProofStatus, err = signature.Verify(session.conf.IrmaConfiguration, request)
-	if err == nil {
-		session.setStatus(irma.ServerStatusDone)
-	} else {
-		if err == irma.ErrMissingPublicKey {
-			rerr = session.fail(server.ErrorUnknownPublicKey, err.Error())
-		} else {
-			rerr = session.fail(server.ErrorUnknown, err.Error())
-		}
+	if err != nil && err == irma.ErrMissingPublicKey {
+		rerr = session.fail(server.ErrorUnknownPublicKey, err.Error())
+	} else if err != nil {
+		rerr = session.fail(server.ErrorUnknown, err.Error())
 	}
+
 	return &irma.ServerSessionResponse{
 		SessionType:     irma.ActionSigning,
 		ProtocolVersion: session.version,
@@ -142,14 +139,10 @@ func (session *session) handlePostDisclosure(disclosure *irma.Disclosure) (*irma
 	request.Disclose = append(request.Disclose, session.implicitDisclosure...)
 
 	session.result.Disclosed, session.result.ProofStatus, err = disclosure.Verify(session.conf.IrmaConfiguration, request)
-	if err == nil {
-		session.setStatus(irma.ServerStatusDone)
-	} else {
-		if err == irma.ErrMissingPublicKey {
-			rerr = session.fail(server.ErrorUnknownPublicKey, err.Error())
-		} else {
-			rerr = session.fail(server.ErrorUnknown, err.Error())
-		}
+	if err != nil && err == irma.ErrMissingPublicKey {
+		rerr = session.fail(server.ErrorUnknownPublicKey, err.Error())
+	} else if err != nil {
+		rerr = session.fail(server.ErrorUnknown, err.Error())
 	}
 
 	return &irma.ServerSessionResponse{
@@ -236,7 +229,6 @@ func (session *session) handlePostCommitments(commitments *irma.IssueCommitmentM
 		sigs = append(sigs, sig)
 	}
 
-	session.setStatus(irma.ServerStatusDone)
 	return &irma.ServerSessionResponse{
 		SessionType:     irma.ActionIssuing,
 		ProtocolVersion: session.version,
@@ -251,7 +243,10 @@ func (session *session) nextSession() (irma.RequestorRequest, irma.AttributeConD
 		return nil, nil, nil
 	}
 	url := base.NextSession.URL
-	if session.result.Status != irma.ServerStatusDone ||
+
+	// Status is changed to DONE as soon as the next session URL is retrieved,
+	// so right now the status must be CONNECTED
+	if session.result.Status != irma.ServerStatusConnected ||
 		session.result.ProofStatus != irma.ProofStatusValid ||
 		session.result.Err != nil {
 		return nil, nil, errors.New("session in invalid state")
@@ -347,6 +342,7 @@ func (s *Server) handleSessionCommitments(w http.ResponseWriter, r *http.Request
 		server.WriteError(w, server.ErrorNextSession, err.Error())
 		return
 	}
+	session.setStatus(irma.ServerStatusDone)
 	server.WriteResponse(w, res, nil)
 }
 
@@ -385,6 +381,7 @@ func (s *Server) handleSessionProofs(w http.ResponseWriter, r *http.Request) {
 		server.WriteError(w, server.ErrorNextSession, err.Error())
 		return
 	}
+	session.setStatus(irma.ServerStatusDone)
 	server.WriteResponse(w, res, nil)
 }