wycheproof

What problem does it solve? Cryptographic implementations are notoriously difficult to get right, and subtle bugs in signature validation, encoding, or padding can expose private keys or enable forgery. This Skill guides you through testing crypto code against the Wycheproof test vector collection to catch known vulnerabilities before they ship. ## Core Features & Use Cases - Test Vector Integration: Add Wycheproof as a git submodule or fetch specific JSON test files, then parse test groups filtered by key size, IV size, or curve. - Testing Harness Patterns: Ready-to-adapt pytest and Mocha examples that handle valid, invalid, and acceptable result flags for algorithms like AES-GCM, ECDSA, ECDH, EdDSA, and RSA. - Vulnerability Detection: Catch signature malleability, invalid DER encoding, invalid curve attacks, padding oracles, and tag forgery, as demonstrated by real CVEs found in the elliptic npm package. - Use Case: You maintain a JavaScript library implementing EdDSA signatures. Use this Skill to load ed25519_test.json, generate parameterized tests, and discover that your implementation accepts signatures with trailing zeros. ## Quick Start Ask the AI to set up Wycheproof test vectors for your AES-GCM implementation and write a pytest harness that validates both encryption and decryption against all test cases.