Release 0.3.0

[kruton]

Release version

0.3.0

Next version

0.3.1-SNAPSHOT

Target branch

main

Release notes

Added

• Added FIDO2 / Security Key authentication helpers for
  sk-ssh-ed25519@openssh.com and sk-ecdsa-sha2-nistp256@openssh.com keys
  in the new org.connectbot.sshlib.sk package. The library handles the SSH
  wire-format pieces while callers provide their own CTAP2 transport.
• Added AuthHandler.onBanner(message) so applications can display
  SSH_MSG_USERAUTH_BANNER messages during authentication.
• Added KtorTcpTransport.getLocalAddress() to expose the local socket address
  assigned to a connected TCP transport.
• Added docs/ALGORITHMS.md with the complete supported algorithm list and
  docs/SK_AUTH.md with Security Key authentication guidance.

Changed

• SshClient(...) and BlockingSshClient(...) convenience constructors now
  require an explicit HostKeyVerifier. This makes host-key verification a
  required caller decision instead of allowing a convenience constructor that
  could not build a valid SshClientConfig.
• AuthHandler.onSignatureRequest() is documented as a verbatim signature
  extension point for local private keys, SSH agents, and FIDO2 authenticators.

Fixed

• Authentication banners are now delivered to callers during every authentication
  step instead of only being logged.
• SshSigning.sign() now rejects sk-* algorithms with an actionable error,
  since Security Key private material lives on the authenticator and must be
  signed through AuthHandler.onSignatureRequest().
• Hardened host-key signature verification by requiring the signature algorithm
  to match the negotiated host-key algorithm.
• Hardened agent session-binding signature verification by requiring the
  signature algorithm to be compatible with the key type.
• Hardened key exchange and channel handling by rejecting all-zero ECDH shared
  secrets, invalid DH group-exchange parameters, channel-window overflows, and
  incoming channel data that exceeds the local receive window.
• Limited zlib decompression output per packet to reduce decompression-bomb
  denial-of-service risk.

[github-actions]

Prepared release PR for v0.3.0 targeting main.

[github-actions]

Published v0.3.0 to main.