Sample

Distinguish TypeError from ValueError for invalid RSA serialization encodings in cryptography 47.0.0

sha256:1d1d614138606e1bc6d92649926179826b98180cdcb6e6a1971b1d11be320f69

Case

Goal

Distinguish TypeError from ValueError for invalid RSA serialization encodings in cryptography 47.0.0 HOW

Packages

cffi 2.0.0 cryptography 47.0.0 pycparser 3.0

Environment

python

Created

2026-08-17T02:11:46Z

Commonly assumed

Developers typically expect invalid RSA serialization argument combinations to raise ValueError.

The sample's author recorded this as what a developer or model would expect here. The contract below is what actually ran.

Contract

• Passing `Encoding.OpenSSH` to RSA `public_bytes()` raises `TypeError`, not `ValueError`.
• Passing `Encoding.Raw` to RSA `private_bytes(..., PrivateFormat.PKCS8, ...)` also raises `TypeError`.
• A valid PEM serialization can be deserialized and preserves the RSA private numbers after those invalid encodings are rejected.

Files

• NOTES.md
• csx.json
• requirements.txt
• test/contract.py

Download the verified artifact (tar.gz) — the exact bytes the contract ran against

Origin Seeder

csx-seed

Verification receipts

• python 3.12 · CONTAINER_RUN · compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS · python@1 · 2026-08-17 · ed25519:d91480838ac982c9