Coverage for /pythoncovmergedfiles/medio/medio/src/model-transparency/tests/fuzzing/fuzz_sign_with_invalid_key.py: 29%

1###### Coverage stub 

2import atexit 

3import coverage 

4cov = coverage.coverage(data_file='.coverage', cover_pylib=True) 

5cov.start() 

6# Register an exist handler that will print coverage 

7def exit_handler(): 

8 cov.stop() 

9 cov.save() 

10atexit.register(exit_handler) 

11####### End of coverage stub 

12# Copyright 2025 The Sigstore Authors 

13# 

14# Licensed under the Apache License, Version 2.0 (the "License"); 

15# you may not use this file except in compliance with the License. 

16# You may obtain a copy of the License at 

17# 

18# http://www.apache.org/licenses/LICENSE-2.0 

19# 

20# Unless required by applicable law or agreed to in writing, software 

21# distributed under the License is distributed on an "AS IS" BASIS, 

22# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 

23# See the License for the specific language governing permissions and 

24# limitations under the License. 

25 

26import os 

27import sys 

28import tempfile 

29 

30# type: ignore 

31import atheris 

32from cryptography.hazmat.primitives import serialization 

33 

34import model_signing 

35 

36 

37def TestOneInput(data): 

38 """Fuzzer running on OSS-Fuzz. 

39 

40 Create a random model and key file, 

41 then sign with the random key file. 

42 Parse the key early to ignore if invalid. 

43 """ 

44 fdp = atheris.FuzzedDataProvider(data) 

45 

46 pubkey_size = fdp.ConsumeIntInRange(0, 8 * 1024) 

47 key_bytes = fdp.ConsumeBytes(pubkey_size) 

48 try: 

49 serialization.load_pem_private_key( 

50 key_bytes, password=None, unsafe_skip_rsa_key_validation=True 

51 ) 

52 except ValueError as e: 

53 print(e) 

54 return 

55 

56 with tempfile.TemporaryDirectory(prefix="mt_sign_only_") as tmpdir: 

57 model_path = os.path.join(tmpdir, "model.bin") 

58 model_size = fdp.ConsumeIntInRange(0, 64 * 1024) 

59 with open(model_path, "wb") as f: 

60 f.write(fdp.ConsumeBytes(model_size)) 

61 

62 key_path = os.path.join(tmpdir, "fuzz.priv") 

63 with open(key_path, "wb") as f: 

64 f.write(key_bytes) 

65 

66 sig_path = os.path.join(tmpdir, "model.sig") 

67 

68 scfg = model_signing.signing.Config() 

69 signer = scfg.use_elliptic_key_signer(private_key=key_path) 

70 _ = signer.sign(model_path, sig_path) 

71 

72 

73def main(): 

74 atheris.instrument_all() 

75 atheris.Setup(sys.argv, TestOneInput) 

76 atheris.Fuzz() 

77 

78 

79if __name__ == "__main__": 

80 main()