Live testing against a real macOS Screen Sharing server surfaced two
real bugs, independent of each other:
1. SessionTab::requestConnectOptions() never prompted for a password
on VNC profiles (only SSH/RDP) -- every VNC connection went out
with an empty password regardless of what the server needed. VNC
now gets its own prompt; an empty password is allowed through
(unlike RDP's hard requirement) since no-auth VNC servers exist and
there's no way to know client-side before the security-type
negotiation happens.
2. VncSessionBackend's Apple DH (type 30) response sent the client's
public key before the encrypted credentials. Cross-checking against
neatvnc's rfb-proto.h (an independent, authoritative reference: both
the wire struct definitions and the full server-side verification
code, matched field-by-field against this implementation) showed
the correct order is credentials first, then public key -- exactly
backwards from what was implemented. Fixed, with a new regression
test that decrypts the credentials back out using the trailing
public-key bytes to derive the shared secret, which would fail if
the fields were swapped again.
Also adds security type 33 (RSA + AES, src/vnc_apple_rsa_auth.h) as a
fallback Apple auth scheme, sourced from the `asyncvnc` PyPI package.
Preference when multiple are offered: None > AppleDH(30) >
AppleRSA(33) > VNCAuth(2).
Neither scheme has been gotten working live yet against the specific
macOS Tahoe (26.6.2) server available for testing -- type 30's wire
format is now verified correct byte-for-byte against the independent
reference above, but the server still rejects it with a generic
"Authentication or authorization failure"; type 33 is rejected even
earlier, right after the initial host-key request. macOS Tahoe was
released after this assistant's knowledge cutoff, so there may be a
protocol or permission-model change specific to it that isn't
reflected in either reference. Documented as an open issue in
docs/PROGRESS.md rather than claimed as working.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
