Cert Tool is a versatile Chrome extension designed for the generation and management of X.509 certificates and cryptographic keys. It offers a range of features including key pair generation, Certificate Signing Request (CSR) creation, and public key derivation. The extension employs the Web Crypto API to ensure the secure generation of key pairs using various algorithms such as RSA and ECDSA, with options to export keys in standard formats. Users can easily download their keys using a familiar OS save dialog, enhancing the overall user experience.

In addition to key management, Cert Tool allows users to create customizable CSRs through a user-friendly interface, supporting multiple Subject Alternative Names (SANs). The tool also provides capabilities for public key derivation from different input types, automatically detecting the format and algorithm used. Furthermore, the certificate and CSR inspector feature gives users access to detailed information about their certificates, including serial numbers and validity periods, with human-readable decoding of critical extensions.