Upstream AmneziaWG 3.x is still shifting under active development
(unanswered kernel-module issues around header protection and
handshake-without-data regressions), so give operators an explicit
opt-out/opt-in instead of always auto-selecting 3.1, and pin the
installed package so unattended-upgrades can't swap the module under
a live server. Surface the running module/tools version and protocol
generation through /health, the CLI status command, and the panel's
server card so a mismatch is visible instead of silent.
Protocol generation is now derived from awg1.conf rather than stored: an
interface speaks 3.1 when HeaderProtectionKey is set and 2.0 otherwise. The
3.0/3.1-only keys (HeaderProtectionKey, ContentPaddingAddition, the
Rekey/Reject/Keepalive timers, MaxHandshakeAttempts, RandomTrailers,
DisableCookies) are read from the conf and emitted only when non-empty, so 2.0
output stays byte-identical — verified by diffing both the client .conf and the
full vpn:// string against the previous implementation.
Changing generation invalidates every issued vpn:// key, so add
POST /api/users/reissue. It recovers the client private key from inside the
stored blob (the only place it exists), keeping ip/pub_key/psk_key intact, so
nothing changes on the wire and users only need to re-import. users gains
key_gen and vpn_key_prev, and users.db is snapshotted before the pass.
install.sh gates 3.1 on module 3.x and kernel >= 5.5 (header protection needs
the chacha library API, absent before 5.5) and falls back to writing a 2.0 conf
instead of aborting, so older kernels keep working as before.
HeaderProtectionKey is generated with awg genpsk and preserved on KEEP_DATA.
The panel marks keys issued on a different generation and offers to reissue
them; /api/v1 now returns gen alongside name/ip/vpn_key.
Also add MIT license headers across the awg-ui sources.