From 48abb1cbc138cd9c013369ea4608dd2fe5ca7a62 Mon Sep 17 00:00:00 2001
From: David Lakin <github@themoderndev.com>
Date: Sat, 4 May 2024 14:40:26 -0400
Subject: [PATCH 1/2] Add git.Blob fuzz target

Based on the `test_blob.py` unit test.
---
 fuzzing/dictionaries/fuzz_blob.dict |  1 +
 fuzzing/fuzz-targets/fuzz_blob.py   | 36 +++++++++++++++++++++++++++++
 2 files changed, 37 insertions(+)
 create mode 100644 fuzzing/dictionaries/fuzz_blob.dict
 create mode 100644 fuzzing/fuzz-targets/fuzz_blob.py

diff --git a/fuzzing/dictionaries/fuzz_blob.dict b/fuzzing/dictionaries/fuzz_blob.dict
new file mode 100644
index 000000000..7f123f830
--- /dev/null
+++ b/fuzzing/dictionaries/fuzz_blob.dict
@@ -0,0 +1 @@
+"\\377\\377\\377\\377\\377\\377\\377\\377" 
diff --git a/fuzzing/fuzz-targets/fuzz_blob.py b/fuzzing/fuzz-targets/fuzz_blob.py
new file mode 100644
index 000000000..9d296de40
--- /dev/null
+++ b/fuzzing/fuzz-targets/fuzz_blob.py
@@ -0,0 +1,36 @@
+import atheris
+import sys
+import os
+import tempfile
+
+if getattr(sys, "frozen", False) and hasattr(sys, "_MEIPASS"):
+    path_to_bundled_git_binary = os.path.abspath(os.path.join(os.path.dirname(__file__), "git"))
+    os.environ["GIT_PYTHON_GIT_EXECUTABLE"] = path_to_bundled_git_binary
+
+with atheris.instrument_imports():
+    import git
+
+
+def TestOneInput(data):
+    fdp = atheris.FuzzedDataProvider(data)
+
+    with tempfile.TemporaryDirectory() as temp_dir:
+        repo = git.Repo.init(path=temp_dir)
+        blob = git.Blob(
+            repo,
+            **{
+                "binsha": git.Blob.NULL_BIN_SHA,
+                "path": fdp.ConsumeUnicodeNoSurrogates(fdp.remaining_bytes()),
+            },
+        )
+
+        _ = blob.mime_type
+
+
+def main():
+    atheris.Setup(sys.argv, TestOneInput)
+    atheris.Fuzz()
+
+
+if __name__ == "__main__":
+    main()

From 6823e4543f33eb623df14a5a27c9731199de7a4f Mon Sep 17 00:00:00 2001
From: David Lakin <github@themoderndev.com>
Date: Sat, 4 May 2024 15:44:23 -0400
Subject: [PATCH 2/2] Use fuzzed data for all git.Blob arguments

This increases the edges reached by the fuzzer, making for a more
effective test with higher coverage.
---
 fuzzing/fuzz-targets/fuzz_blob.py | 18 +++++++++++-------
 1 file changed, 11 insertions(+), 7 deletions(-)

diff --git a/fuzzing/fuzz-targets/fuzz_blob.py b/fuzzing/fuzz-targets/fuzz_blob.py
index 9d296de40..ce888e85f 100644
--- a/fuzzing/fuzz-targets/fuzz_blob.py
+++ b/fuzzing/fuzz-targets/fuzz_blob.py
@@ -16,13 +16,17 @@ def TestOneInput(data):
 
     with tempfile.TemporaryDirectory() as temp_dir:
         repo = git.Repo.init(path=temp_dir)
-        blob = git.Blob(
-            repo,
-            **{
-                "binsha": git.Blob.NULL_BIN_SHA,
-                "path": fdp.ConsumeUnicodeNoSurrogates(fdp.remaining_bytes()),
-            },
-        )
+        binsha = fdp.ConsumeBytes(20)
+        mode = fdp.ConsumeInt(fdp.ConsumeIntInRange(0, fdp.remaining_bytes()))
+        path = fdp.ConsumeUnicodeNoSurrogates(fdp.remaining_bytes())
+
+        try:
+            blob = git.Blob(repo, binsha, mode, path)
+        except AssertionError as e:
+            if "Require 20 byte binary sha, got" in str(e):
+                return -1
+            else:
+                raise e
 
         _ = blob.mime_type