A cipher can round-trip perfectly against our own implementation and
still be wrong: header layout, padding rules, and nonce ordering are only
pinned down by talking to another implementation. This drives ss-local
against rust's ssserver and rust's sslocal against ss-server, over a
local origin server so it needs no network access.
Covers the three SIP022 methods plus aes-256-gcm, so a regression in the
legacy path shows up here too. Skips itself when shadowsocks-rust or the
built binaries are absent, so it is safe to run anywhere.
Max Lv
3728a993a7