From 9ea8676d24b65a23b91bf4bcf8c9cf1ae2f3f6d4 Mon Sep 17 00:00:00 2001
From: realaravinth <realaravinth@batsense.net>
Date: Wed, 8 Dec 2021 13:43:24 +0530
Subject: [PATCH] pow_sha256 serializes the phrase on which the proof is to be
 computed using the bincode crate, which uses UTF-8 under the hood and also
 prefixes the length of the string in big endian.

This patch introduces changes to implement the same
---
 jest.config.ts |  4 +++-
 src/index.ts   | 33 ++++++++++++++++++++++++++++-----
 src/test.ts    | 29 ++++++++++++++++++-----------
 3 files changed, 49 insertions(+), 17 deletions(-)

diff --git a/jest.config.ts b/jest.config.ts
index eaabac1..61aa637 100644
--- a/jest.config.ts
+++ b/jest.config.ts
@@ -2,7 +2,6 @@
  * For a detailed explanation regarding each configuration property and type check, visit:
  * https://jestjs.io/docs/en/configuration.html
  */
-
 export default {
   // All imported modules in your tests should be mocked automatically
   // automock: false,
@@ -16,6 +15,8 @@ export default {
   // Automatically clear mock calls and instances between every test
   clearMocks: true,
 
+  testTimeout: 300000,
+
   // Indicates whether the coverage information should be collected while executing the test
   collectCoverage: true,
 
@@ -31,6 +32,7 @@ export default {
     "setupTests.ts",
     "setUpTests.ts",
     "jest.setup.ts",
+    "test-data.ts",
   ],
 
   // Indicates which provider should be used to instrument code for coverage
diff --git a/src/index.ts b/src/index.ts
index 2fc5244..9c1b456 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -10,6 +10,29 @@
  */
 
 const U128_MAX = 340282366920938463463374607431768211455n;
+const encoder = new TextEncoder();
+const decoder = new TextDecoder("utf-8");
+
+const length_metadata = (len: number): number[] => {
+  return [
+    (len & 0x00000000000000ff) >> 0,
+    (len & 0x000000000000ff00) >> 8,
+    (len & 0x0000000000ff0000) >> 16,
+    (len & 0x00000000ff000000) >> 24,
+    (len & 0x000000ff00000000) >> 32,
+    (len & 0x0000ff000000000) >> 48,
+    (len & 0x00ff00000000000) >> 56,
+    Number((BigInt(len) & 0xff0000000000000n) >> BigInt(64)),
+  ];
+};
+
+const serialize = (message: string): Uint8Array => {
+  const len_encoded = length_metadata(message.length);
+  const msgUint8 = new Uint8Array(
+    len_encoded.concat(Array.from(encoder.encode(message)))
+  );
+  return msgUint8;
+};
 
 /**
  * Compute SHA-256 digest of a string
@@ -17,8 +40,8 @@ const U128_MAX = 340282366920938463463374607431768211455n;
  * @returns {number[]} - byte array of the hash
  **/
 export const digest = async (message: string): Promise<number[]> => {
-  const msgUint8 = new TextEncoder().encode(message);
-  msgUint8;
+  const msgUint8 = encoder.encode(message);
+
   const hashBuffer = await crypto.subtle.digest("SHA-256", msgUint8);
   const hashArray = Array.from(new Uint8Array(hashBuffer));
   return hashArray;
@@ -65,11 +88,11 @@ export const generate_work = async (
   phrase: string,
   difficulty: number
 ): Promise<WasmWork> => {
-  const base = salt + phrase;
+  const serialized_phrase = decoder.decode(serialize(phrase));
+  const base = salt + serialized_phrase;
   let nonce = 0;
   let result: BigInt = BigInt(0);
-  const difficulty_new = U128_MAX - (U128_MAX / BigInt(difficulty));
-  console.log(difficulty_new==340275561273600044694105339939619576091n);
+  const difficulty_new = U128_MAX - U128_MAX / BigInt(difficulty);
   while (result < difficulty_new) {
     nonce += 1;
     const hash = await digest(base + nonce.toString());
diff --git a/src/test.ts b/src/test.ts
index 1ed8cb9..2539fa5 100644
--- a/src/test.ts
+++ b/src/test.ts
@@ -3,20 +3,27 @@ import { DATA, DIFFICULTY, SALT } from "./test-data";
 
 ("use strict");
 
-it("Everything works", async () => {
+test("Proof generation works", async () => {
   for (let i = 0; i < DATA.length; i++) {
     const d = DATA[i];
     try {
-      const res = await digest(d.phrase);
-      expect(res).toStrictEqual(d.hash);
-      //expect(await w.digest(d.phrase)).toBe(d.hash);
-      expect(score(d.hash)).toBe(d.difficulty);
-      //let proof = await generate_work(SALT, d.phrase, DIFFICULTY);
-      //console.log(
-      //  `saved nonce:${d.pow.nonce} proof result: ${proof.result}proof nonce: ${proof.nonce}`
-      //);
-      //expect(proof.nonce).toBe(d.pow.nonce);
-      //expect(proof.result).toBe(d.pow.result);
+      const proof = await generate_work(SALT, d.phrase, DIFFICULTY);
+      expect(proof.nonce).toBe(d.pow.nonce);
+      expect(proof.result).toBe(`${d.pow.result}`);
+    } catch (error) {
+      console.log(`${d.pow.nonce}${error}`);
+      throw error;
+    }
+  }
+});
+
+test("Digest works", async () => {
+  for (let i = 0; i < DATA.length; i++) {
+    const d = DATA[i];
+    try {
+      const res = await digest(d.phrase);
+      expect(res).toStrictEqual(d.hash);
+      expect(score(d.hash)).toBe(d.difficulty);
     } catch (error) {
       console.log(`${d.pow.nonce}${error}`);
       throw error;