fix: mask multiline secrets

- do not try to mask a secret when a log line is received
- try to mask secrets before before sending a batch of log
  lines to the Forgejo instance (every second)
- if masking a multiline secret needs more log lines to decide
  if it needs to be masked, do not attempt to send anything to
  the Forgejo instance, just wait until there are more log lines

Closes forgejo/runner#57

internal/pkg/report/reporter.go

@@ -31,8 +31,7 @@ type Reporter struct {
 
 	logOffset      int
 	logRows        []*runnerv1.LogRow
-	logReplacer    *strings.Replacer
-	oldnew         []string
+	masker         *masker
 	reportInterval time.Duration
 
 	state   *runnerv1.TaskState
@@ -44,24 +43,23 @@ type Reporter struct {
 }
 
 func NewReporter(ctx context.Context, cancel context.CancelFunc, c client.Client, task *runnerv1.Task, reportInterval time.Duration) *Reporter {
-	var oldnew []string
+	masker := newMasker()
 	if v := task.Context.Fields["token"].GetStringValue(); v != "" {
-		oldnew = append(oldnew, v, "***")
+		masker.add(v)
 	}
 	if v := client.BackwardCompatibleContext(task, "runtime_token"); v != "" {
-		oldnew = append(oldnew, v, "***")
+		masker.add(v)
 	}
 	for _, v := range task.Secrets {
-		oldnew = append(oldnew, v, "***")
+		masker.add(v)
 	}
 
 	rv := &Reporter{
 		ctx:            ctx,
 		cancel:         cancel,
 		client:         c,
-		oldnew:         oldnew,
+		masker:         masker,
 		reportInterval: reportInterval,
-		logReplacer:    strings.NewReplacer(oldnew...),
 		state: &runnerv1.TaskState{
 			Id: task.Id,
 		},
@@ -290,6 +288,10 @@ func (r *Reporter) ReportLog(noMore bool) error {
 		return nil
 	}
 
+	if needMore := r.masker.replace(rows, noMore); needMore {
+		return NewErrRetry(errRetryNeedMoreRows)
+	}
+
 	resp, err := r.client.UpdateLog(r.ctx, connect.NewRequest(&runnerv1.UpdateLogRequest{
 		TaskId: r.state.Id,
 		Index:  int64(r.logOffset),
@@ -402,7 +404,7 @@ func (r *Reporter) handleCommand(originalContent, command, parameters, value str
 
 	switch command {
 	case "add-mask":
-		r.addMask(value)
+		r.masker.add(value)
 		return nil
 	case "debug":
 		if r.debugOutputEnabled {
@@ -449,15 +451,8 @@ func (r *Reporter) parseLogRow(entry *log.Entry) *runnerv1.LogRow {
 		}
 	}
 
-	content = r.logReplacer.Replace(content)
-
 	return &runnerv1.LogRow{
 		Time:    timestamppb.New(entry.Time),
 		Content: strings.ToValidUTF8(content, "?"),
 	}
 }
-
-func (r *Reporter) addMask(msg string) {
-	r.oldnew = append(r.oldnew, msg, "***")
-	r.logReplacer = strings.NewReplacer(r.oldnew...)
-}