splitted one operator module to file, account, image operators; splitted operator functions; etc

app/imageoper/imgaux.go

@@ -0,0 +1,59 @@
+/*
+ * Copyright 2026 Oleg Borodin <onborodin@gmail.com>
+ *
+ * This work is published and licensed under a Creative Commons
+ * Attribution-NonCommercial-NoDerivatives 4.0 International License.
+ *
+ * Distribution of this work is permitted, but commercial use and
+ * modifications are strictly prohibited.
+ */
+package imageoper
+
+import (
+	"encoding/hex"
+	"strings"
+)
+
+const sha256prefix = "sha256:"
+const sha512prefix = "sha512:"
+
+func normalizeSHADigest(digest string) string {
+	if stringLikeSHA256Digest(digest) && !strings.HasPrefix(digest, sha256prefix) {
+		digest = sha256prefix + digest
+	} else if stringLikeSHA512Digest(digest) && !strings.HasPrefix(digest, sha512prefix) {
+		digest = sha512prefix + digest
+	}
+	return digest
+}
+
+func stringLikeSHADigest(some string) bool {
+	return stringLikeSHA256Digest(some) || stringLikeSHA512Digest(some)
+}
+
+func stringLikeSHA256Digest(some string) bool {
+	if strings.HasPrefix(some, sha256prefix) {
+		some = strings.TrimPrefix(some, sha256prefix)
+	}
+	_, err := hex.DecodeString(some)
+	if err != nil {
+		return false
+	}
+	if len(some) == 64 {
+		return true
+	}
+	return false
+}
+
+func stringLikeSHA512Digest(some string) bool {
+	if strings.HasPrefix(some, sha512prefix) {
+		some = strings.TrimPrefix(some, sha512prefix)
+	}
+	_, err := hex.DecodeString(some)
+	if err != nil {
+		return false
+	}
+	if len(some) == 128 {
+		return true
+	}
+	return false
+}