1 files changed, 55 insertions, 0 deletions
diff --git a/projects/gcp-python-cloud-storage/fuzz_fileio.py b/projects/gcp-python-cloud-storage/fuzz_fileio.py
new file mode 100644
index 00000000..e8ca853c
--- /dev/null
+++ b/projects/gcp-python-cloud-storage/fuzz_fileio.py
@@ -0,0 +1,55 @@
+#!/usr/bin/python3
+# Copyright 2022 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import atheris
+import sys
+import mock
+
+with atheris.instrument_imports():
+    from google.cloud.storage.fileio import BlobReader
+
+
+global_data = None
+def TestOneInput(data):
+    global_data = data
+    fdp = atheris.FuzzedDataProvider(data)
+
+    blob = mock.Mock()
+    def read_fuzz_data(start=0, end=None, **_):
+        return global_data[start:end]
+
+    blob.download_as_bytes = mock.Mock(side_effect=read_fuzz_data)
+    blob.size = len(data)
+    blob.chunk_size = None
+    download_kwargs = {"if_metageneration_match": 1}
+    reader = BlobReader(blob, **download_kwargs)
+    try:
+        reader.read(fdp.ConsumeIntInRange(0, len(data)*2))
+    except UnicodeDecodeError:
+        return
+
+    reader.seek(
+        pos = fdp.ConsumeIntInRange(0, len(data)*2),
+        whence = fdp.ConsumeIntInRange(0, 2)
+    )
+
+
+def main():
+    atheris.instrument_all()
+    atheris.Setup(sys.argv, TestOneInput, enable_python_coverage=True)
+    atheris.Fuzz()
+
+if __name__ == "__main__":
+    main()