Factor more potentially offline operations out of JS code

CCTF_Solutions_main/frontend/src/main.mjs

@@ -1,6 +1,13 @@
 import sha256 from 'crypto-js/sha256.js';
 import { initialize } from 'zokrates-js';
 
+window.addEventListener('load', () => {
+	document.getElementById('submitFlagBtn')
+		.addEventListener('click', () => {
+		submitFlag(document.getElementById('flagbox').value);
+	});
+});
+
 const ZEROSTR = '0';
 
 /* Converts a string into a stringified hexadecimal number */
@@ -54,25 +61,15 @@ function expand_number(number) {
 	return [...Array(8 - parts.length).fill(ZEROSTR), ...parts];
 }
 
-
-/* Hard coded zokrates program source code */
-const zokSrc = `
-import "hashes/sha256/sha256Padded.zok" as sha256;
-from "utils/casts.zok" import cast;
-
-def main(public u32[8] hash,public u32[5] address,private u8[64] flag){
-     u8[20] addr8 = cast(address);
-     u32[8] genHash = sha256(flag);
-     log("Hash: {} {} {} {} {} {} {} {}",genHash[0],genHash[1],genHash[2],genHash[3],genHash[4],genHash[5],genHash[6],genHash[7]);
-     assert(genHash == hash);
-     return;
-}
-`;
-
+const proving_key = await (await fetch('/zok_proving.key')).text();
+const program = await (await fetch('/zok_program')).arrayBuffer();
+const abi = await (await fetch('/zok_abi.json')).json();
 
 /* Get the proving key from the local server */
-const PROVING_KEY_URI = '/proving.key';
+const PROVING_KEY_URI = 'http://localhost:8080/proving.key';
 const proving_key = await (await fetch(PROVING_KEY_URI)).text();
+const artefacts = { program: new Uint8Array(program), abi: abi };
+console.log(artefacts);
 
 function submitFlag(flag) {
 	initialize().then((defaultProvider) => {
@@ -81,8 +78,6 @@ function submitFlag(flag) {
 			scheme: 'gm17',
 		});
 
-		const artefacts = zokProvider.compile(zokSrc);
-
 		const flag_ascii = str2asciiarr(flag);
 		const flag_ascii_padded = flag_ascii.concat(new Array(64 - flag_ascii.length).fill(0));
 		const flag_padded = asciiarr2str(flag_ascii_padded);
@@ -96,15 +91,13 @@ function submitFlag(flag) {
 		const addr_split = map_0xprefix(addr.match(/.{1,8}/g));
 
 		// witness computation
+		console.log('witness');
 		const { witness, output } = zokProvider.computeWitness(artefacts, [hash_split, addr_split, flag_split_padded]);
 
 		// generate proof
+		console.log('proof');
 		const proof = zokProvider.generateProof(artefacts.program, witness, proving_key);
 
 		console.log(proof);
 	});
-}
-
-document.getElementById('submitFlagBtn').addEventListener('click', () => {
-	submitFlag(document.getElementById('flagbox').value);
-});
+};

CCTF_Solutions_main/frontend/zok_abi.json

@@ -0,0 +1,37 @@
+{
+  "inputs": [
+    {
+      "name": "hash",
+      "public": true,
+      "type": "array",
+      "components": {
+        "size": 8,
+        "type": "u32"
+      }
+    },
+    {
+      "name": "address",
+      "public": true,
+      "type": "array",
+      "components": {
+        "size": 5,
+        "type": "u32"
+      }
+    },
+    {
+      "name": "flag",
+      "public": false,
+      "type": "array",
+      "components": {
+        "size": 64,
+        "type": "u8"
+      }
+    }
+  ],
+  "output": {
+    "type": "tuple",
+    "components": {
+      "elements": []
+    }
+  }
+}