Add HashMismatchError for download hash validation failures

monai/apps/__init__.py

@@ -13,4 +13,13 @@
 
 from .datasets import CrossValidation, DecathlonDataset, MedNISTDataset, TciaDataset
 from .mmars import MODEL_DESC, RemoteMMARKeys, download_mmar, get_model_spec, load_from_mmar
-from .utils import SUPPORTED_HASH_TYPES, check_hash, download_and_extract, download_url, extractall, get_logger, logger
+from .utils import (
+    SUPPORTED_HASH_TYPES,
+    HashMismatchError,
+    check_hash,
+    download_and_extract,
+    download_url,
+    extractall,
+    get_logger,
+    logger,
+)

monai/apps/utils.py

@@ -42,7 +42,20 @@
 else:
     tqdm, has_tqdm = optional_import("tqdm", "4.47.0", min_version, "tqdm")
 
-__all__ = ["check_hash", "download_url", "extractall", "download_and_extract", "get_logger", "SUPPORTED_HASH_TYPES"]
+__all__ = [
+    "check_hash",
+    "download_url",
+    "extractall",
+    "download_and_extract",
+    "get_logger",
+    "HashMismatchError",
+    "SUPPORTED_HASH_TYPES",
+]
+
+
+class HashMismatchError(RuntimeError):
+    """Raised when the hash of a downloaded file does not match the expected value."""
+
 
 DEFAULT_FMT = "%(asctime)s - %(levelname)s - %(message)s"
 SUPPORTED_HASH_TYPES = {"md5": hashlib.md5, "sha1": hashlib.sha1, "sha256": hashlib.sha256, "sha512": hashlib.sha512}
@@ -213,7 +226,7 @@ def download_url(
             https://github.com/wkentaro/gdown/blob/main/gdown/download.py
 
     Raises:
-        RuntimeError: When the hash validation of the ``filepath`` existing file fails.
+        HashMismatchError: When the hash validation of the ``filepath`` existing file fails.
         RuntimeError: When a network issue or denied permission prevents the
             file download from ``url`` to ``filepath``.
         URLError: See urllib.request.urlretrieve.
@@ -268,7 +281,7 @@ def download_url(
         pass
     logger.info(f"Downloaded: {filepath}")
     if not check_hash(filepath, hash_val, hash_type):
-        raise RuntimeError(
+        raise HashMismatchError(
             f"{hash_type} check of downloaded file failed: URL={url}, "
             f"filepath={filepath}, expected {hash_type}={hash_val}."
         )

tests/test_utils.py

@@ -41,7 +41,7 @@
 import torch
 import torch.distributed as dist
 
-from monai.apps.utils import download_url
+from monai.apps.utils import HashMismatchError, download_url
 from monai.config import NdarrayTensor
 from monai.config.deviceconfig import USE_COMPILED
 from monai.config.type_definitions import NdarrayOrTensor
@@ -81,7 +81,6 @@
     "unexpected EOF",  # incomplete download
     "network issue",
     "gdown dependency",  # gdown not installed
-    "md5 check",
     "limit",  # HTTP Error 503: Egress is over the account limit
     "authenticate",
     "timed out",  # urlopen error [Errno 110] Connection timed out
@@ -173,6 +172,8 @@ def skip_if_downloading_fails():
 
     try:
         yield
+    except HashMismatchError:
+        raise
     except DOWNLOAD_EXCEPTS as e:
         raise unittest.SkipTest(f"Error while downloading: {e}") from e
     except ssl.SSLError as ssl_e:
@@ -208,7 +209,7 @@ def test_download_url(self):
                     hash_val=SAMPLE_TIFF_HASH,
                     hash_type=SAMPLE_TIFF_HASH_TYPE,
                 )
-            with self.assertRaises(RuntimeError):
+            with self.assertRaises(HashMismatchError):
                 download_url(
                     url=SAMPLE_TIFF,
                     filepath=os.path.join(tempdir, "model_bad.tiff"),