SetPassword derives a full Argon2 hash, so the [password command, the admin
gump, account creation and the XML import each cost ~8.9 ms of frozen world.
Only the login verify had been moved.
DRY-ing the two paths surfaced a correctness trap rather than just shared
code. ApplyPasswordUpgrade guarded by comparing the stored hash, which is
right for a login rehash -- do not clobber a newer password with a rehash of
the one it superseded -- but wrong for an explicit change: two changes
dispatched before either landed would drop the second and silently keep the
older password. Ordering is now a per-account dispatch sequence claimed on
the loop, which gives "newest wins" for both callers through one mechanism.
SetPassword bumps it as well, so an inline write also supersedes an in-flight
one.
One job type serves both: PasswordJob carries an optional verify phrase and
an optional hash phrase plus an OnComplete that runs on the loop, so a login
verifies and may rehash while a password change only hashes. The class is
PasswordWorker now, since verification no longer describes what it does.
PasswordWorker.SetPassword is the single entry point and falls back to
hashing inline when the gate is off or the queue is saturated -- unlike a
login, a password change must never be silently dropped, and it is rare
enough that the loop can absorb one.
The [password confirmation moves into the callback, because off the loop it
has not happened when the call returns. Account creation stays inline: it
gates the login flow, so deferring it restructures the accept path.
An Argon2 verify is ~8.9 ms of frozen world per login attempt, successful or
not, so a credential flood is a full-cost stall per packet without needing
valid credentials. Measurement puts the on-loop saving at 3.5-8.9 ms: the
hand-off costs ~220 ns, and the only real residue is the loop's own work
slowing while a memory-hard KDF evicts shared L3.
One worker, not a pool. The per-login contention tax falls with concurrency
while total loop damage rises, so one hasher harms the loop least; and a
single hasher cannot cost the loop more than the inline verify under any
scheduling regime, because at worst it takes an equal share of one core.
That bound is what lets the measurement extrapolate to hardware we cannot
inspect, and a pool breaks it. It also caps live Argon2 arenas at one,
which answers memory exhaustion without a separate mechanism.
Scoped to Argon2-stored accounts. SHA and MD5 protections share a
HashAlgorithm instance whose ComputeHash is not thread safe, and they cost
microseconds anyway. Their one-time rehash into Argon2 stays on the loop
too: it costs a migrating account a single 8.9 ms login exactly as today.
The worker parks on an AutoResetEvent and never spins. The spin in
SerializationThreadWorker exists to wait on a producer mid-drain; there is
no such race here, so this is strictly cheaper at idle. It yields while the
world is in PendingSave or Saving -- PendingSave included, because the
serialization threads are already awake and spinning on an empty queue by
then.
Phrase derivation moves to AccountSecurity.DerivePhrase so verification and
rehash cannot disagree about the rule, which is the shape of the lockout
fixed in #2562. ApplyPasswordUpgrade refuses to write when the stored hash
changed while the verify ran, so a password set mid-flight is not replaced
by a rehash of the one it superseded.
**Only one functional change**
* Fixes a bug in LogFactory where `Warning` is being logged as `Information`
Non-functional changes:
* Updates/Fixes copyright headers
* Removes namespace scopes for core files.
View with [whitespace off](https://github.com/modernuo/ModernUO/pull/1187/files?w=1).
* Fixes an issue with moving directories across volumes
* Removes usages of WebClient
* Removes usages of Cryptographic Providers
Note: Even though .NET 6 introduces Xoshiro RNG, there is no way to control the seed. I'll do some reconciliation of Xoshiro so it functions closer to the built in one. For the most part, it has parity though.
Benchmarks show there is nothing odd about the implementations, they are within 1ns of each other.
