Fixes relative paths handling issues

rpm-ima-inspector.py

@@ -220,10 +220,23 @@ class TapProducer:
     counter = staticmethod(counter)
 
 
+def normalize_path(path: str) -> str:
+    """
+    Returns an absolute path with all variables expanded.
+
+    Args:
+        path: path to be normalized.
+
+    Returns:
+        Normalized path.
+    """
+    return os.path.abspath(os.path.expanduser(os.path.expandvars(path)))
+
+
 def main():
     arg_parser = init_arg_parser()
     args = arg_parser.parse_args()
-    rpm_file = args.rpm_file
+    rpm_file = normalize_path(args.rpm_file)
     tap = TapProducer()
     #
     step = 'load public IMA certificate'
@@ -247,7 +260,7 @@ def main():
     failed = False
     with unpack_rpm_to_tmp(rpm_file) as rpm_dir:
         for rel_path, sig_hdr in ima_sigs:
-            file_path = os.path.join(rpm_dir, rel_path)
+            file_path = os.path.join(rpm_dir, os.path.relpath(rel_path, '/'))
             if not os.path.isfile(file_path) or os.path.islink(file_path):
                 tap.skipped(f'{rel_path} is not a regular file')
                 continue