70 lines
2.1 KiB
Dart
70 lines
2.1 KiB
Dart
// Session token management — mirrors k_proxy_app.py session logic.
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// Tokens are 32-byte hex strings; stored in memory only.
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import 'dart:math';
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class SessionEntry {
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final String username;
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final DateTime expires;
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SessionEntry({required this.username, required this.expires});
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}
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class SessionManager {
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final Map<String, SessionEntry> _sessions = {};
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static const Duration _ttl = Duration(seconds: 300);
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/// Issue a new session token for [username].
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/// _purgeExpired is only called here, not on every lookup, so tokens accumulate
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/// until the next login — acceptable for the low-traffic embedded use case.
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String issue(String username) {
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_purgeExpired();
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final token = _randomToken();
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_sessions[token] = SessionEntry(
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username: username,
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expires: DateTime.now().add(_ttl),
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);
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return token;
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}
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/// Returns the session entry for [token], or null if missing/expired.
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SessionEntry? getSession(String token) {
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final s = _sessions[token];
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if (s == null) return null;
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if (DateTime.now().isAfter(s.expires)) {
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_sessions.remove(token);
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return null;
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}
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return s;
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}
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/// Returns true if [token] is known and not expired.
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bool isValid(String token) => getSession(token) != null;
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/// Revoke [token] immediately.
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void revoke(String token) => _sessions.remove(token);
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/// Returns true if at least one session is currently active (not expired).
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/// Used by gated-proxy forwarding: personal-device model means any live
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/// login counts as authorisation for the proxied request.
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bool hasAnyActiveSession() {
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_purgeExpired();
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return _sessions.isNotEmpty;
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}
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/// Revoke all sessions for [username].
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void revokeAll(String username) {
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_sessions.removeWhere((_, s) => s.username == username);
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}
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void _purgeExpired() {
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final now = DateTime.now();
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_sessions.removeWhere((_, s) => now.isAfter(s.expires));
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}
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String _randomToken() {
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final rng = Random.secure();
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final bytes = List.generate(32, (_) => rng.nextInt(256));
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return bytes.map((b) => b.toRadixString(16).padLeft(2, '0')).join();
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}
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}
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