Catch panics in some goroutines

manager.go

@@ -605,6 +605,14 @@ func (cm *CredentialManager) unenrolledKeyshareServers() []SchemeManagerIdentifi
 // KeyshareEnroll attempts to enroll at the keyshare server of the specified scheme manager.
 func (cm *CredentialManager) KeyshareEnroll(manager SchemeManagerIdentifier, email, pin string) {
 	go func() {
+		defer func() {
+			handlePanic(func(err *SessionError) {
+				if cm.handler != nil {
+					cm.handler.EnrollmentError(manager, err)
+				}
+			})
+		}()
+
 		err := cm.keyshareEnrollWorker(manager, email, pin)
 		cm.UnenrolledKeyshareServers = cm.unenrolledKeyshareServers()
 		if err != nil {
@@ -613,6 +621,7 @@ func (cm *CredentialManager) KeyshareEnroll(manager SchemeManagerIdentifier, ema
 			cm.handler.EnrollmentSuccess(manager)
 		}
 	}()
+
 }
 
 func (cm *CredentialManager) keyshareEnrollWorker(managerID SchemeManagerIdentifier, email, pin string) error {

messages.go

@@ -105,6 +105,8 @@ const (
 	ErrorConfigurationStoreDownload = ErrorType("configurationStoreDownload")
 	// IRMA requests refers to unknown scheme manager
 	ErrorUnknownSchemeManager = ErrorType("unknownSchemeManager")
+	// Recovered panic
+	ErrorPanic = ErrorType("panic")
 )
 
 func (e *SessionError) Error() string {

session.go

@@ -133,6 +133,25 @@ func (cm *CredentialManager) NewSession(qr *Qr, handler Handler) {
 	return
 }
 
+func handlePanic(callback func(*SessionError)) {
+	if e := recover(); e != nil {
+		var info string
+		switch x := e.(type) {
+		case string:
+			info = x
+		case error:
+			info = x.Error()
+		case fmt.Stringer:
+			info = x.String()
+		default: // nop
+		}
+		fmt.Printf("Recovered from panic: '%v'\n%s\n", e, info)
+		if callback != nil {
+			callback(&SessionError{ErrorType: ErrorPanic, Info: info})
+		}
+	}
+}
+
 func (session *session) fail(err *SessionError) {
 	session.transport.Delete()
 	err.Err = errors.Wrap(err.Err, 0)
@@ -153,6 +172,14 @@ func (session *session) cancel() {
 // start retrieves the first message in the IRMA protocol, checks if we can perform
 // the request, and informs the user of the outcome.
 func (session *session) start() {
+	defer func() {
+		handlePanic(func(err *SessionError) {
+			if session.Handler != nil {
+				session.Handler.Failure(session.Action, err)
+			}
+		})
+	}()
+
 	session.Handler.StatusUpdate(session.Action, StatusCommunicating)
 
 	if session.Action == ActionSchemeManager {
@@ -253,6 +280,14 @@ func (session *session) start() {
 }
 
 func (session *session) do(proceed bool) {
+	defer func() {
+		handlePanic(func(err *SessionError) {
+			if session.Handler != nil {
+				session.Handler.Failure(session.Action, err)
+			}
+		})
+	}()
+
 	if !proceed {
 		session.cancel()
 		return