fixed github issue 3774 for custom detector secret size (#3816)

pkg/custom_detectors/custom_detectors.go

@@ -32,6 +32,7 @@ type CustomRegexWebhook struct {
 // Ensure the Scanner satisfies the interface at compile time.
 var _ detectors.Detector = (*CustomRegexWebhook)(nil)
 var _ detectors.CustomFalsePositiveChecker = (*CustomRegexWebhook)(nil)
+var _ detectors.MaxSecretSizeProvider = (*CustomRegexWebhook)(nil)
 
 // NewWebhookCustomRegex initializes and validates a CustomRegexWebhook. An
 // unexported type is intentionally returned here to ensure the values have
@@ -115,6 +116,11 @@ func (c *CustomRegexWebhook) IsFalsePositive(_ detectors.Result) (bool, string)
 	return false, ""
 }
 
+// custom max size for custom detector
+func (c *CustomRegexWebhook) MaxSecretSize() int64 {
+	return 1000
+}
+
 func (c *CustomRegexWebhook) createResults(ctx context.Context, match map[string][]string, verify bool, results chan<- detectors.Result) error {
 	if common.IsDone(ctx) {
 		// TODO: Log we're possibly leaving out results.