Validate normalize retry diagnostics

internal/framework/pipeline/normalize_retry.go

@@ -0,0 +1,34 @@
+package pipeline
+
+import (
+	"errors"
+	"strings"
+	"unicode/utf8"
+
+	"gitea.maximumdirect.net/eric/notarius/internal/framework/contracts"
+)
+
+func validateNormalizeRetry(retry *contracts.NormalizeRetry) error {
+	if retry == nil {
+		return errors.New("normalize retry directive is missing")
+	}
+	if !utf8.ValidString(retry.ReasonCode) {
+		return errors.New("normalize retry directive reason code has invalid UTF-8")
+	}
+	if strings.TrimSpace(retry.ReasonCode) == "" {
+		return errors.New("normalize retry directive reason code is blank")
+	}
+	if len(retry.ReasonCode) > contracts.MaxNormalizeRetryReasonCodeBytes {
+		return errors.New("normalize retry directive reason code exceeds maximum length")
+	}
+	if !utf8.ValidString(retry.Message) {
+		return errors.New("normalize retry directive message has invalid UTF-8")
+	}
+	if strings.TrimSpace(retry.Message) == "" {
+		return errors.New("normalize retry directive message is blank")
+	}
+	if len(retry.Message) > contracts.MaxNormalizeRetryMessageBytes {
+		return errors.New("normalize retry directive message exceeds maximum length")
+	}
+	return nil
+}