shared/import-util: Tag renamed to reference

Added (sha256) digest validation function

src/shared/import-util.c

@@ -150,6 +150,27 @@ int raw_strip_suffixes(const char *p, char **ret) {
         return 0;
 }
 
+bool dkr_digest_is_valid(const char *digest) {
+        /* 7 chars for prefix, 64 chars for the digest itself */
+        if (strlen(digest) != 71)
+                return false;
+
+        return startswith(digest, "sha256:") && in_charset(digest + 7, "0123456789abcdef");
+}
+
+bool dkr_ref_is_valid(const char *ref) {
+        const char *colon;
+
+        if (isempty(ref))
+                return false;
+
+        colon = strchr(ref, ':');
+        if (!colon)
+                return filename_is_valid(ref);
+
+        return dkr_digest_is_valid(ref);
+}
+
 bool dkr_name_is_valid(const char *name) {
         const char *slash, *p;
 

src/shared/import-util.h

@@ -44,4 +44,6 @@ int raw_strip_suffixes(const char *name, char **ret);
 
 bool dkr_name_is_valid(const char *name);
 bool dkr_id_is_valid(const char *id);
+bool dkr_ref_is_valid(const char *ref);
+bool dkr_digest_is_valid(const char *digest);
 #define dkr_tag_is_valid(tag) filename_is_valid(tag)