SSH Keytool

Generate, convert and inspect SSH keys and certificates offline, including FIDO security keys (ed25519-sk / ecdsa-sk).

A secure, offline-capable Chrome Extension for generating SSH key pairs, deriving public keys, inspecting SSH certificates, and converting private keys between OpenSSH, PEM (PKCS#1/PKCS#8), and PuTTY PPK formats — directly in your browser. **Features** • Generate SSH keys: RSA (2048/4096), Ed25519 and ECDSA (P-256/384/521), with optional passphrase protection. • FIDO security keys: build ssh-keygen commands for ed25519-sk / ecdsa-sk with resident, PIN-required and no-touch options, plus matching authorized_keys, sshd_config and Git signing snippets. • Inspect FIDO keys: see the application, SHA256 fingerprint and touch / PIN / resident flags of sk- public keys and key files, including passphrase-protected ones. • Convert private keys between OpenSSH, PKCS#1, PKCS#8 and PuTTY PPK, and add, change or remove a passphrase in the same step. • Derive the OpenSSH public key from a private key (FIDO key files included). • Inspect SSH certificates: key ID, principals, validity window, extensions and critical options. PRIVACY All cryptography runs locally inside the extension. The only permission requested is clipboard write, used by the Copy buttons. Open source: https://github.com/mkontani/ssh-keytool-extension