support for variable number of datagroups in circuit

circuits/circuits/Sha256BytesStatic.circom

@@ -3,9 +3,9 @@ pragma circom 2.1.5;
 include "circomlib/circuits/bitify.circom";
 include "circomlib/circuits/sha256/sha256.circom";
 
-template Sha256Bytes(max_num_bytes) {
+// Static length sha256 bytes, adapted from zk-email
+template Sha256BytesStatic(max_num_bytes) {
     signal input in_padded[max_num_bytes];
-    // signal input in_len_padded_bytes;
     signal output out[256];
 
     var num_bits = max_num_bytes * 8;
@@ -19,7 +19,6 @@ template Sha256Bytes(max_num_bytes) {
             sha.in[i*8+j] <== bytes[i].out[7-j];
         }
     }
-    // sha.in_len_padded_bits <== in_len_padded_bytes * 8;
 
     for (var i = 0; i < 256; i++) {
         out[i] <== sha.out[i];

circuits/circuits/passport_verifier.circom

@@ -2,18 +2,20 @@ pragma circom 2.1.5;
 
 include "@zk-email/circuits/helpers/rsa.circom";
 include "@zk-email/circuits/helpers/extract.circom";
-include "./sha256Bytes.circom";
+include "@zk-email/circuits/helpers/sha.circom";
+include "./Sha256BytesStatic.circom";
 
-template PassportVerifier(n, k) {
+template PassportVerifier(n, k, max_datahashes_bytes) {
     signal input mrz[93]; // formatted mrz (5 + 88) chars
-    signal input dataHashes[297];
+    signal input dataHashes[max_datahashes_bytes];
+    signal input datahashes_padded_length;
     signal input eContentBytes[104];
 
     signal input pubkey[k];
     signal input signature[k];
 
     // compute sha256 of formatted mrz
-    signal mrzSha[256] <== Sha256Bytes(93)(mrz);
+    signal mrzSha[256] <== Sha256BytesStatic(93)(mrz);
 
     // get output of sha256 into bytes to check against dataHashes
     component sha256_bytes[32];
@@ -29,8 +31,8 @@ template PassportVerifier(n, k) {
         dataHashes[31 + i] === sha256_bytes[i].out;
     }
 
-    // hash dataHashes
-    signal dataHashesSha[256] <== Sha256Bytes(297)(dataHashes);
+    // hash dataHashes dynamically
+    signal dataHashesSha[256] <== Sha256Bytes(max_datahashes_bytes)(dataHashes, datahashes_padded_length);
 
     // get output of dataHashes sha256 into bytes to check against eContent
     component dataHashes_sha256_bytes[32];
@@ -47,7 +49,7 @@ template PassportVerifier(n, k) {
     }
 
     // hash eContentBytes
-    signal eContentSha[256] <== Sha256Bytes(104)(eContentBytes);
+    signal eContentSha[256] <== Sha256BytesStatic(104)(eContentBytes);
 
     // get output of eContentBytes sha256 into k chunks of n bits each
     var msg_len = (256 + n) \ n;

circuits/circuits/proof_of_passport.circom

@@ -4,9 +4,10 @@ include "circomlib/circuits/poseidon.circom";
 include "@zk-email/circuits/helpers/extract.circom";
 include "./passport_verifier.circom";
 
-template ProofOfPassport(n, k) {
+template ProofOfPassport(n, k, max_datahashes_bytes) {
     signal input mrz[93]; // formatted mrz (5 + 88) chars
-    signal input dataHashes[297];
+    signal input dataHashes[max_datahashes_bytes];
+    signal input datahashes_padded_length;
     signal input eContentBytes[104];
     signal input pubkey[k];
     signal input signature[k];
@@ -15,9 +16,10 @@ template ProofOfPassport(n, k) {
     signal input address;
 
     // Verify passport
-    component PV = PassportVerifier(n, k);
+    component PV = PassportVerifier(n, k, max_datahashes_bytes);
     PV.mrz <== mrz;
     PV.dataHashes <== dataHashes;
+    PV.datahashes_padded_length <== datahashes_padded_length;
     PV.eContentBytes <== eContentBytes;
     PV.pubkey <== pubkey;
     PV.signature <== signature;
@@ -45,7 +47,7 @@ template ProofOfPassport(n, k) {
     }
 }
 
-component main { public [ address ] } = ProofOfPassport(64, 32);
+component main { public [ address ] } = ProofOfPassport(64, 32, 320);
 
 // Us:
 // 11 + 1 + 3 + 1

circuits/package.json

@@ -11,7 +11,9 @@
     "@types/node": "^20.6.3",
     "@types/node-forge": "^1.3.5",
     "@zk-email/circuits": "^3.2.2",
+    "@zk-email/helpers": "^3.1.3",
     "chai-as-promised": "^7.1.1",
+    "circom_tester": "^0.0.20",
     "circomlib": "^2.0.5",
     "js-sha256": "^0.10.1",
     "node-forge": "^1.3.1",

circuits/scripts/build_circuit.sh

@@ -1,5 +1,8 @@
 #!/bin/bash
 
+# Record the start time
+START_TIME=$(date +%s)
+
 # Check if the first argument is "app-only"
 if [ "$1" == "app-only" ]; then
     echo "Building only for the app"
@@ -39,4 +42,9 @@ yarn snarkjs zkey export verificationkey build/proof_of_passport_final.zkey buil
 
 yarn snarkjs zkey export solidityverifier build/proof_of_passport_final.zkey build/Verifier.sol
 cp build/Verifier.sol ../contracts/contracts/Verifier.sol
-echo "copied Verifier.sol to contracts"
+echo "copied Verifier.sol to contracts"
+
+# Calculate and print the time taken by the whole script
+END_TIME=$(date +%s)
+ELAPSED_TIME=$(($END_TIME - $START_TIME))
+echo "Build completed in $ELAPSED_TIME seconds"

circuits/test/passport.test.ts

@@ -1,12 +1,14 @@
 import { describe } from 'mocha'
 import chai, { assert, expect } from 'chai'
 import chaiAsPromised from 'chai-as-promised'
-import { hash, toUnsignedByte, arraysAreEqual, bytesToBigDecimal, formatAndConcatenateDataHashes, formatMrz, splitToWords } from '../../common/src/utils/utils'
+import { hash, toUnsignedByte, arraysAreEqual, bytesToBigDecimal, formatMrz, splitToWords } from '../../common/src/utils/utils'
 import { groth16 } from 'snarkjs'
-import { DataHash } from '../../common/src/utils/types'
 import { getPassportData } from '../../common/src/utils/passportData'
-import { attributeToPosition } from '../../common/src/constants/constants'
+import { MAX_DATAHASHES_LEN, attributeToPosition } from '../../common/src/constants/constants'
+import { sha256Pad } from '@zk-email/helpers'
+import path from "path";
 const fs = require('fs');
+const wasm_tester = require("circom_tester").wasm;
 
 chai.use(chaiAsPromised)
 
@@ -21,13 +23,9 @@ describe('Circuit tests', function () {
     const passportData = getPassportData();
 
     const formattedMrz = formatMrz(passportData.mrz);
-    const mrzHash = hash(formatMrz(passportData.mrz));
-    const concatenatedDataHashes = formatAndConcatenateDataHashes(
-      mrzHash,
-      passportData.dataGroupHashes as DataHash[],
-    );
-    
-    const concatenatedDataHashesHashDigest = hash(concatenatedDataHashes);
+
+    const concatenatedDataHashesHashDigest = hash(passportData.dataGroupHashes);
+    console.log('concatenatedDataHashesHashDigest', concatenatedDataHashesHashDigest);
 
     assert(
       arraysAreEqual(passportData.eContent.slice(72, 72 + 32), concatenatedDataHashesHashDigest),
@@ -36,10 +34,16 @@ describe('Circuit tests', function () {
 
     const reveal_bitmap = Array(88).fill('1');
 
+    const [messagePadded, messagePaddedLen] = sha256Pad(
+      new Uint8Array(passportData.dataGroupHashes),
+      MAX_DATAHASHES_LEN
+    );
+
     inputs = {
       mrz: formattedMrz.map(byte => String(byte)),
       reveal_bitmap: reveal_bitmap.map(byte => String(byte)),
-      dataHashes: concatenatedDataHashes.map(toUnsignedByte).map(byte => String(byte)),
+      dataHashes: Array.from(messagePadded).map((x) => x.toString()),
+      datahashes_padded_length: messagePaddedLen.toString(),
       eContentBytes: passportData.eContent.map(toUnsignedByte).map(byte => String(byte)),
       pubkey: splitToWords(
         BigInt(passportData.pubKey.modulus),
@@ -53,7 +57,8 @@ describe('Circuit tests', function () {
       ),
       address: "0x70997970c51812dc3a010c7d01b50e0d17dc79c8", // sample address
     }
-    
+
+    console.log('inputs', inputs);
   })
   
   describe('Proof', function() {
@@ -210,6 +215,19 @@ describe('Circuit tests', function () {
 
 
   })
+
+  // use these tests with .only to check changes without rebuilding the zkey
+  describe('Circom tester tests', function() {
+    it('should prove and verify with valid inputs', async function () {
+      const circuit = await wasm_tester(
+        path.join(__dirname, `../circuits/proof_of_passport.circom`),
+        { include: ["node_modules"] },
+      );
+      const w = await circuit.calculateWitness(inputs);
+      await circuit.checkConstraints(w);
+    })
+  })
+
 })