From 867c7080d718ebf6122291579b980f80f079721b Mon Sep 17 00:00:00 2001
From: Chris Duncan <chris@codecow.com>
Date: Sun, 9 Aug 2026 21:29:27 -0700
Subject: [PATCH] Solidify vault timer implementation.

---
 src/lib/vault/vault-timer.ts  | 21 +++++++++++++++++++++
 src/lib/vault/vault-worker.ts | 33 +++++++++++++++++----------------
 2 files changed, 38 insertions(+), 16 deletions(-)

diff --git a/src/lib/vault/vault-timer.ts b/src/lib/vault/vault-timer.ts
index bbde2b7..0bfe634 100644
--- a/src/lib/vault/vault-timer.ts
+++ b/src/lib/vault/vault-timer.ts
@@ -1,6 +1,11 @@
 //! SPDX-FileCopyrightText: 2025 Chris Duncan <chris@codecow.com>
 //! SPDX-License-Identifier: GPL-3.0-or-later
 
+/**
+ * Executes a function after a timeout, with additional controls to manage the
+ * timer. Note: `this.#ticker` is a no-op every second in order to keep the
+ * timer from being put to sleep by the system.
+ */
 export class VaultTimer {
 	#f: () => any
 	#isPaused: boolean = false
@@ -27,6 +32,14 @@ export class VaultTimer {
 		}
 	}
 
+	reset (t: number) {
+		this.stop()
+		this.#remaining = t
+		this.#start = performance.now()
+		this.#ticker = setInterval(Function.prototype, 1000)
+		this.#timeout = setTimeout(this.#f, this.#remaining)
+	}
+
 	resume () {
 		if (this.#isPaused) {
 			this.#start = performance.now()
@@ -35,4 +48,12 @@ export class VaultTimer {
 			this.#isPaused = false
 		}
 	}
+
+	stop () {
+		clearTimeout(this.#timeout)
+		clearInterval(this.#ticker)
+		this.#remaining = 0
+		this.#start = 0
+		this.#isPaused = false
+	}
 }
diff --git a/src/lib/vault/vault-worker.ts b/src/lib/vault/vault-worker.ts
index e326e7a..1bf5b19 100644
--- a/src/lib/vault/vault-worker.ts
+++ b/src/lib/vault/vault-worker.ts
@@ -16,7 +16,7 @@ import { VaultTimer } from './vault-timer'
 
 let _locked: boolean = true
 let _timeout: number = 120_000
-let _timer: VaultTimer = new VaultTimer(() => { }, 0)
+let _timer: VaultTimer = new VaultTimer(_autolock, _timeout)
 let _type: 'BIP-44' | 'BLAKE2b' | 'Exodus' | undefined = undefined
 let _id: UUID | undefined = undefined
 let _seed: ArrayBuffer | undefined = undefined
@@ -128,24 +128,25 @@ NODE: parentPort?.on('message', listener)
  */
 function config (timeout?: number): Promise<void> {
 	try {
-		_timer?.pause()
+		_timer.pause()
 		if (_locked) {
 			throw new VaultError('Wallet is locked')
 		}
-		if (typeof timeout === 'number') {
-			if (timeout < 10) {
-				throw new VaultError('Timeout must be at least 10 seconds')
-			}
-			if (timeout > 600) {
-				throw new VaultError('Timeout must be at most 10 minutes')
-			}
-			_timeout = timeout * 1000
-			_timer = new VaultTimer(_autolock, _timeout)
+		if (typeof timeout !== 'number') {
+			throw new TypeError('Invalid timeout period', { cause: timeout })
 		}
+		if (timeout < 10) {
+			throw new VaultError('Timeout must be at least 10 seconds')
+		}
+		if (timeout > 600) {
+			throw new VaultError('Timeout must be at most 10 minutes')
+		}
+		_timeout = timeout * 1000
+		_timer.reset(_timeout)
 		return Promise.resolve()
 	} catch (err) {
 		console.error(err)
-		_timer?.resume()
+		_timer.resume()
 		throw new VaultError('Failed to configure Vault', { cause: err })
 	}
 }
@@ -219,7 +220,7 @@ function derive (index?: number | Uint32Array): Promise<Record<string, number |
 				for (const result of results) {
 					data[result.index] = result.publicKey
 				}
-				_timer = new VaultTimer(_autolock, _timeout)
+				_timer.reset(_timeout)
 				return data
 			})
 			.catch(err => {
@@ -299,7 +300,7 @@ function sign (index?: Uint32Array, data?: ArrayBuffer): Promise<Record<string,
 				pub.fill(0)
 				const sig = nano25519_sign(new Uint8Array(data), sk)
 				sk.fill(0)
-				_timer = new VaultTimer(_autolock, _timeout)
+				_timer.reset(_timeout)
 				return { signature: sig.buffer }
 			})
 			.catch(err => {
@@ -355,7 +356,7 @@ function unlock (type?: WalletType, id?: UUID, key?: CryptoKey, iv?: ArrayBuffer
 					_seed = seed
 					_mnemonic = mnemonic
 					_locked = false
-					_timer = new VaultTimer(_autolock, _timeout)
+					_timer.reset(_timeout)
 					return Promise.resolve({ isLocked: false })
 				})
 				.catch(err => {
@@ -389,7 +390,7 @@ function update (key?: CryptoKey, salt?: ArrayBuffer): Promise<Record<string, Ar
 		}
 		return WalletAesGcm.encrypt(_type, _id, key, _seed, _mnemonic)
 			.then(({ iv, encrypted }) => {
-				_timer = new VaultTimer(_autolock, _timeout)
+				_timer.reset(_timeout)
 				return { iv, salt, encrypted }
 			})
 			.catch(err => {
-- 
2.52.0