From 6a422394de413646d9f487f643e5c94cca26e455 Mon Sep 17 00:00:00 2001
From: Chris Duncan <chris@zoso.dev>
Date: Fri, 8 Aug 2025 14:34:30 -0700
Subject: [PATCH] Store mnemonic as buffer and convert as needed.

---
 src/lib/safe.ts | 28 +++++++++++++++++-----------
 1 file changed, 17 insertions(+), 11 deletions(-)

diff --git a/src/lib/safe.ts b/src/lib/safe.ts
index 08e6ceb..5b965bc 100644
--- a/src/lib/safe.ts
+++ b/src/lib/safe.ts
@@ -19,7 +19,7 @@ export class Safe {
 	static #locked: boolean = true
 	static #type?: 'BIP-44' | 'BLAKE2b'
 	static #seed?: ArrayBuffer
-	static #mnemonic?: string
+	static #mnemonic?: ArrayBuffer
 	static #parentPort?: any
 	static {
 		NODE: this.#parentPort = parentPort
@@ -116,7 +116,7 @@ export class Safe {
 			if (this.#seed == null || this.#mnemonic == null) {
 				throw new Error('Failed to generate seed and mnemonic')
 			}
-			return { ...record, seed: this.#seed.slice(), mnemonic: utf8.toBuffer(this.#mnemonic) }
+			return { ...record, seed: this.#seed.slice(), mnemonic: this.#mnemonic.slice() }
 		} catch (err) {
 			throw new Error('Failed to create wallet', { cause: err })
 		} finally {
@@ -227,8 +227,8 @@ export class Safe {
 			if (!(this.#seed instanceof ArrayBuffer)) {
 				throw new TypeError('Invalid seed')
 			}
-			if (this.#mnemonic != null && typeof this.#mnemonic !== 'string') {
-				throw new TypeError('Invalid seed')
+			if (this.#mnemonic != null && !(this.#mnemonic instanceof ArrayBuffer)) {
+				throw new TypeError('Invalid mnemonic')
 			}
 			this.#locked = false
 			return { isUnlocked: !this.#locked }
@@ -283,13 +283,19 @@ export class Safe {
 				let diff = 0
 				const userSeed = new Uint8Array(seed)
 				const thisSeed = new Uint8Array(this.#seed)
-				for (let i = 0; i < seed.byteLength; i++) {
+				for (let i = 0; i < userSeed.byteLength; i++) {
 					diff |= userSeed[i] ^ thisSeed[i]
 				}
 				isVerified = diff === 0
 			}
-			if (mnemonicPhrase != null && mnemonicPhrase === this.#mnemonic) {
-				isVerified = true
+			if (mnemonicPhrase != null) {
+				let diff = 0
+				const userMnemonic = utf8.toBytes(mnemonicPhrase)
+				const thisMnemonic = new Uint8Array(this.#mnemonic ?? [])
+				for (let i = 0; i < userMnemonic.byteLength; i++) {
+					diff |= userMnemonic[i] ^ thisMnemonic[i]
+				}
+				isVerified = diff === 0
 			}
 			return { isVerified }
 		} catch (err) {
@@ -318,7 +324,7 @@ export class Safe {
 		const additionalData = utf8.toBytes(type)
 		const decrypted = new Uint8Array(await crypto.subtle.decrypt({ name: 'AES-GCM', iv, additionalData }, key, encrypted))
 		this.#seed = decrypted.buffer.slice(0, seedLength)
-		this.#mnemonic = bytes.toUtf8(decrypted.slice(seedLength))
+		this.#mnemonic = decrypted.buffer.slice(seedLength)
 		decrypted.fill(0)
 	}
 
@@ -351,7 +357,7 @@ export class Safe {
 			throw new Error('Wallet seed not found')
 		}
 		const seed = new Uint8Array(this.#seed)
-		const mnemonic = utf8.toBytes(this.#mnemonic ?? '')
+		const mnemonic = new Uint8Array(this.#mnemonic ?? [])
 		// restrict iv to 96 bits per GCM best practice
 		const iv = crypto.getRandomValues(new Uint8Array(12)).buffer
 		const additionalData = utf8.toBytes(this.#type)
@@ -527,11 +533,11 @@ export class Safe {
 			if (secret instanceof ArrayBuffer) {
 				this.#seed = secret
 				if (type === 'BLAKE2b') {
-					this.#mnemonic = (await Bip39.fromEntropy(new Uint8Array(secret))).phrase
+					this.#mnemonic = utf8.toBuffer((await Bip39.fromEntropy(new Uint8Array(secret))).phrase ?? '')
 				}
 			} else {
 				const mnemonic = await Bip39.fromPhrase(secret)
-				this.#mnemonic = mnemonic.phrase
+				this.#mnemonic = utf8.toBuffer(mnemonic.phrase ?? '')
 				this.#seed = type === 'BIP-44'
 					? (await mnemonic.toBip39Seed(mnemonicSalt ?? '')).buffer
 					: (await mnemonic.toBlake2bSeed()).buffer
-- 
2.47.3