From: Chris Duncan <chris@zoso.dev>
Date: Fri, 8 Aug 2025 21:22:54 +0000 (-0700)
Subject: Set safe seed and mnemonic directly from decryption method instead of returning.... 
X-Git-Tag: v0.10.5~41^2~163
X-Git-Url: https://git.codecow.com/?a=commitdiff_plain;h=3a41fb3235a0ff38cbb9683b6ee0ce435c188e98;p=libnemo.git

Set safe seed and mnemonic directly from decryption method instead of returning. Encode and decode bytes explicitly to avoid string handling.
---

diff --git a/src/lib/safe.ts b/src/lib/safe.ts
index 6aecb1e..08e6ceb 100644
--- a/src/lib/safe.ts
+++ b/src/lib/safe.ts
@@ -223,15 +223,13 @@ export class Safe {
 			if (encrypted == null) {
 				throw new TypeError('Wallet encrypted data is required')
 			}
-			const { seed, mnemonic } = await this.#decryptWallet(type, key, iv, encrypted)
-			if (!(seed instanceof ArrayBuffer)) {
+			await this.#decryptWallet(type, key, iv, encrypted)
+			if (!(this.#seed instanceof ArrayBuffer)) {
 				throw new TypeError('Invalid seed')
 			}
-			if (mnemonic != null && typeof mnemonic !== 'string') {
+			if (this.#mnemonic != null && typeof this.#mnemonic !== 'string') {
 				throw new TypeError('Invalid seed')
 			}
-			this.#seed = seed
-			if (mnemonic != null) this.#mnemonic = (await Bip39.fromPhrase(mnemonic)).phrase
 			this.#locked = false
 			return { isUnlocked: !this.#locked }
 		} catch (err) {
@@ -315,22 +313,13 @@ export class Safe {
 		return await crypto.subtle.deriveKey(derivationAlgorithm, derivationKey, derivedKeyType, false, [purpose])
 	}
 
-	static async #decryptWallet (type: string, key: CryptoKey, iv: ArrayBuffer, encrypted: ArrayBuffer): Promise<NamedData<string | ArrayBuffer>> {
-		let decrypted, decoded, parsed
-
+	static async #decryptWallet (type: string, key: CryptoKey, iv: ArrayBuffer, encrypted: ArrayBuffer): Promise<void> {
+		const seedLength = type === 'BIP-44' ? 64 : 32
 		const additionalData = utf8.toBytes(type)
-		decrypted = new Uint8Array(await crypto.subtle.decrypt({ name: 'AES-GCM', iv, additionalData }, key, encrypted))
-		decoded = bytes.toUtf8(decrypted)
-		bytes.erase(decrypted)
-		decrypted = undefined
-
-		parsed = JSON.parse(decoded)
-		decoded = undefined
-
-		const seed = hex.toBuffer(parsed.seed)
-		const mnemonic = parsed.mnemonic
-		parsed = parsed.seed = parsed.mnemonic = undefined
-		return { seed, mnemonic }
+		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))
+		decrypted.fill(0)
 	}
 
 	/**
@@ -361,15 +350,12 @@ export class Safe {
 		if (this.#seed == null) {
 			throw new Error('Wallet seed not found')
 		}
-		const data: NamedData<string> = {
-			seed: bytes.toHex(new Uint8Array(this.#seed))
-		}
-		if (this.#mnemonic != null) data.mnemonic = this.#mnemonic
-
+		const seed = new Uint8Array(this.#seed)
+		const mnemonic = utf8.toBytes(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)
-		const encoded = utf8.toBytes(JSON.stringify(data))
+		const encoded = new Uint8Array([...seed, ...mnemonic])
 		const encrypted = await crypto.subtle.encrypt({ name: 'AES-GCM', iv, additionalData }, key, encoded)
 		return { iv, encrypted }
 	}