wycheproof

Wycheproof is a cryptographic testing skill focused on validating the correctness and security of cryptographic implementations using standardized test vectors. It helps developers identify weaknesses in crypto code by testing implementations against known attacks, malformed inputs, and edge cases. The project provides structured input/output test cases that verify whether cryptographic operations correctly accept valid data and reject invalid or dangerous inputs. This reduces the risk of vulnerabilities such as signature forgery, invalid curve attacks, message decryption flaws, and interoperability issues between different implementations.

The skill includes extensive test vector coverage for established cryptographic algorithms including AES-GCM, AES-EAX, ChaCha20-Poly1305, ECDSA, EdDSA, RSA-PSS, RSA-PKCS1, and ECDH. Test vectors are organized into test groups that share attributes such as key sizes, curves, or initialization vector parameters. The repository provides JSON-based test vector files, schemas, and reference testing harnesses for Java and JavaScript environments. It supports workflows for parsing vectors, writing automated validation harnesses, and integrating crypto verification into CI/CD pipelines. The newer `testvectors_v1` directory provides more detailed test metadata and is recommended for new integrations.

This skill is intended for security engineers, cryptographic library maintainers, backend developers, auditors, and teams building applications that rely on secure encryption or digital signatures. It is especially useful when validating third-party cryptographic code, testing protocol implementations, or ensuring consistent behavior across platforms. Wycheproof is best suited for established cryptographic algorithms and known attack scenarios rather than discovering entirely new vulnerabilities or testing timing side-channel resistance.