passport tree

common/src/utils/passportTree.ts

@@ -0,0 +1,72 @@
+import { poseidon9, poseidon2 } from "poseidon-lite"
+import { IMT } from '@zk-kit/imt'
+import { stringToAsciiBigIntArray } from "./utils";
+
+export function buildPassTree(passports :any[]){
+    let leaves: BigInt[] = []
+    let startTime = performance.now();
+    for (let i = 0; i < passports.length; i++) {
+        const passport = passports[i]
+
+        if (i !== 0) {
+          console.log('Processing passport number', i, "out of", passports.length);
+        }
+
+        if (passport.Pass_No.length > 9) {
+          console.log('passport length is greater than 9:', i, passport)
+          continue
+        } else if (passport.Pass_No.length < 9){
+          while (passport.Pass_No.length != 9) {
+            passport.Pass_No += '<'
+          }
+        }
+        
+        // Add some form of passport validation either here or in py script for json formation ? 
+        // console.log(passport.Pass_No)
+        // console.log(stringToAsciiBigIntArray(passport.Pass_No).length)
+        const leaf = getOfacLeaf(stringToAsciiBigIntArray(passport.Pass_No), i)
+        if (!leaf) {
+          continue
+        }
+        leaves.push(leaf)
+      } 
+
+    console.log("Total passports paresed are : ", leaves.length," over ",passports.length )
+
+    // What depth is optimal ?
+    const tree = new IMT(poseidon2, 16, 0, 2, leaves)
+    console.log('passport tree built in', performance.now() - startTime, 'ms')
+    verifyProof(tree, passports)
+    return tree
+}
+
+// JUST TESTING THE PROOF
+export function verifyProof(tree :IMT ,passports :any[]) {
+  const passno =  passports[5].Pass_No
+  const leaf = getOfacLeaf(stringToAsciiBigIntArray(passno))
+  const index = tree.indexOf(leaf);
+  if (index === -1) {
+    throw new Error("Your public key was not found in the registry");
+  } else {
+    console.log("Index of passport in the registry: ", index);
+  }
+
+  const proof = tree.createProof(index);
+  console.log("verifyProof", tree.verifyProof(proof));
+} 
+
+// change this to take passports ascii array 
+export function getOfacLeaf(passport: any, i?: number): bigint {
+  if (passport.length !== 9) {
+    console.log('parsed passport length is not 9:', i, passport)
+    return
+  }
+  // change into bigint if not already
+  try {
+    return poseidon9(passport)
+  } catch (err) {
+    console.log('err : passport', err, i, passport)
+  }
+}
+
+