From 670a4f78b69a4f3a11840828b84a9a626ac340fe Mon Sep 17 00:00:00 2001
From: Apotheosis <97164662+0xApotheosis@users.noreply.github.com>
Date: Wed, 18 Oct 2023 10:39:55 +1100
Subject: [PATCH] perf: optimize seed creation

---
 .../crypto/isolation/engines/default/bip39.ts | 42 ++++++-------------
 1 file changed, 13 insertions(+), 29 deletions(-)

diff --git a/packages/hdwallet-native/src/crypto/isolation/engines/default/bip39.ts b/packages/hdwallet-native/src/crypto/isolation/engines/default/bip39.ts
index a7c1cafa0..beeb2438f 100644
--- a/packages/hdwallet-native/src/crypto/isolation/engines/default/bip39.ts
+++ b/packages/hdwallet-native/src/crypto/isolation/engines/default/bip39.ts
@@ -2,6 +2,7 @@
 
 import * as core from "@shapeshiftoss/hdwallet-core";
 import * as bip32crypto from "bip32/src/crypto";
+import { createSHA512, pbkdf2 } from "hash-wasm";
 import { TextEncoder } from "web-encoding";
 
 import * as BIP32 from "../../core/bip32";
@@ -12,34 +13,6 @@ import { Revocable, revocable } from "./revocable";
 
 export * from "../../core/bip39";
 
-// Poor man's single-block PBKDF2 implementation
-//TODO: get something better
-function pbkdf2_sha512_singleblock(
-  password: string,
-  salt: Uint8Array,
-  iterations: number
-): Uint8Array & { length: 64 } {
-  function be32Buf(index: number): Buffer {
-    const indexBE = Buffer.alloc(4);
-    indexBE.writeUInt32BE(index);
-    return indexBE;
-  }
-
-  const pwBuffer = safeBufferFrom(new TextEncoder().encode(password));
-
-  const out = bip32crypto.hmacSHA512(pwBuffer, core.compatibleBufferConcat([salt, be32Buf(1)])) as Buffer & {
-    length: 64;
-  };
-  let lastU = out;
-  for (let i = 2; i <= iterations; i++) {
-    const newU = bip32crypto.hmacSHA512(pwBuffer, lastU) as Buffer & { length: 64 };
-    for (let j = 0; j < out.length; j++) out[j] ^= newU[j];
-    lastU = newU;
-  }
-
-  return out;
-}
-
 export class Mnemonic extends Revocable(class {}) implements BIP39.Mnemonic {
   readonly #mnemonic: string;
 
@@ -59,7 +32,18 @@ export class Mnemonic extends Revocable(class {}) implements BIP39.Mnemonic {
     const mnemonic = this.#mnemonic;
     const salt = new TextEncoder().encode(`mnemonic${passphrase ?? ""}`.normalize("NFKD"));
 
-    const out = await BIP32Engine.Seed.create(pbkdf2_sha512_singleblock(mnemonic, salt, 2048));
+    const out = await BIP32Engine.Seed.create(
+      Buffer.from(
+        await pbkdf2({
+          password: mnemonic,
+          salt,
+          iterations: 2048,
+          hashLength: 64,
+          hashFunction: createSHA512(),
+          outputType: "binary",
+        })
+      )
+    );
     this.addRevoker(() => out.revoke?.());
     return out;
   }