task 8

mover/sahab328/code/task8/get_flag.ts

@@ -0,0 +1,41 @@
+import { getFullnodeUrl, SuiClient } from "@mysten/sui/client";
+import { bcs, toHex, fromHex, fromBase64 } from '@mysten/bcs';
+import { createHash, getRandomValues } from "crypto";
+
+
+async function get_flag(sender: string) {
+    const obj_id = "0x19e76ca504c5a5fa5e214a45fca6c058171ba333f6da897b82731094504d5ab9";
+    const client = new SuiClient({ url: getFullnodeUrl("testnet") });
+
+    const obj = await client.getObject({ 
+        id: obj_id, 
+        options: {
+            showBcs: true,
+            showContent: true,
+        } 
+    });
+    const content = obj.data!.content as any;
+    const difficulty = content.fields['difficulity'];
+
+    const Address = bcs.bytes(32).transform({
+        input: (val: string) => fromHex(val),
+        output: (val) => toHex(val),
+    });
+    const sender_bcs_bytes = Address.serialize(sender).toBytes();
+    const obj_bcs_bytes = fromBase64((obj.data!.bcs as any)["bcsBytes"])
+    const proof_length = difficulty * 2;
+    const proof_bytes = new Uint8Array(proof_length);
+    while(true) {
+        getRandomValues(proof_bytes);
+        const buffer = Buffer.concat([proof_bytes, sender_bcs_bytes, obj_bcs_bytes]);
+        const hash = createHash('sha3-256').update(buffer).digest();
+        let prefix_sum = 0;
+        for (let k = 0; k < difficulty; ++k) {
+            prefix_sum += hash[k];
+        }
+        if (prefix_sum == 0) {
+            console.log(toHex(proof_bytes));
+            break;
+        }
+    }
+}

mover/sahab328/code/task8/package.json

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+{
+  "name": "task7",
+  "version": "1.0.0",
+  "description": "",
+  "main": "index.js",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "keywords": [],
+  "author": "",
+  "license": "ISC",
+  "dependencies": {
+    "@mysten/sui": "^1.16.0"
+  }
+}