error check for invalid whitelist URI

nfgenes · Mar 5, 2022 · 67b6f95 · 67b6f95
1 parent d6aa2c3
commit 67b6f95
Showing 1 changed file with 93 additions and 82 deletions.
diff --git a/middleware/generateMerkleProof.js b/middleware/generateMerkleProof.js
@@ -7,96 +7,107 @@ const axios = require('axios');
 const express = require('express')
 const router = express.Router()
 
-/**
- *  TO DO: Add a check for a generated tree that is unbalanced. At a minimum
- *  give a notice of unbalaned tree and perhaps add functionality to auto-balance.
- */
-
- let tree;
- let root;
- let leaf
- let leafIndex;
-
-// Takes any full IPFS URI and returns the CID only
-const parseCID = (ipfsURI) => {
-  const uriSplit = ipfsURI.split('/');
-  const ipfsCID = uriSplit[uriSplit.length-1];
-  return ipfsCID;
-}
-
-const generateMerkleTree = async (ipfsURIWhitelist, leafToVerify) => {
-  try {
-
-    const whitelistCID = parseCID(ipfsURIWhitelist);
-
-    const url = 'https://gateway.pinata.cloud/ipfs/' + whitelistCID;
-    const whitelistData = await axios.get(url, {
-      headers: {
-          pinata_api_key: process.env['PINATA_API_KEY'],
-          pinata_secret_api_key: process.env['PINATA_API_SECRET']
-      }
-    })
-
-    console.log(whitelistData.data, 'WHITE LIST DATA RETRIEVAL!?!?!?!');
-
-    tree = new MerkleTree(whitelistData.data, keccak256, {sortPairs: true, sortLeaves: true, sort: true, hashLeaves: true});
-    root = tree.getHexRoot();
-    leaf = leafToVerify;
-  } catch (e) {
-    console.log(e);
-  }
-}
-/**
- * Using the selected leaf value, lookup the corresponding hash
- * and index from the Merkle Tree Summary json file
-*/
-const getLeafHashFromTreeSummary = (leafToVerify) => {
-  try {
-    const leafHash = `0x${keccak256(leafToVerify).toString('hex')}`;
-    console.log(tree.getLeafIndex(leafHash), 'leafIndex');
-    leafIndex = tree.getLeafIndex(leafHash);
-  } catch (e) {
-    console.log(e);
+const runProof = async (ipfsURIWhitelist, leafToVerify) => {
+  let tree;
+  let leaf;
+  let leafIndex;
+  let whitelistDataResponse;
+
+  const fetchWhitelistFromIPFS = async (ipfsURIWhitelist) => {
+    try {
+      const whitelistCID = parseCID(ipfsURIWhitelist);
+
+      const url = 'https://gateway.pinata.cloud/ipfs/' + whitelistCID;
+      const whitelistData = await axios.get(url, {
+        timeout: 3000,
+        headers: {
+            pinata_api_key: process.env['PINATA_API_KEY'],
+            pinata_secret_api_key: process.env['PINATA_API_SECRET']
+        }
+      });
+      whitelistDataResponse = whitelistData.data;
+      console.log(whitelistData.data, 'WHITE LIST DATA RETRIEVAL!?!?!?!');
+      return true;
+    } catch (e) {
+      console.log(e);
+      return false;
+    }
   }
-}
 
-const getProof = () => {
-  try {
-    if (leafIndex == -1) {
-      console.log('Error: value does not exist within the list');
-      return {
-        leaf: leaf,
-        errorMsg: 'Error: value does not exist within the list'
-      }
-    } 
-
-    const leaves = tree.getHexLeaves();
-    const proof = tree.getHexProof(leaves[leafIndex]);
-    const leafValueHex = toHex(leaf);
+  const generateMerkleTree = async (whitelistDataResponse, leafToVerify) => {
+    try {
+      tree = new MerkleTree(whitelistDataResponse, keccak256, {
+        sortPairs: true,
+        sortLeaves: true,
+        sort: true,
+        hashLeaves: true
+      });
+      leaf = leafToVerify;
+    } catch (e) {
+      console.log(e);
+    }
+  }
 
-    const proofObj = {
-        leafValue: leaf,
-        leafHex: leafValueHex,
-        leafHash: leaves[leafIndex],
-        proof: proof
-    };
+  /**
+   * Using the selected leaf value, lookup the corresponding hash
+   * and index from the Merkle Tree Summary json file
+  */
+  const getLeafHashFromTreeSummary = (leafToVerify) => {
+    try {
+      const leafHash = `0x${keccak256(leafToVerify).toString('hex')}`;
+      console.log(tree.getLeafIndex(leafHash), 'leafIndex');
+      leafIndex = tree.getLeafIndex(leafHash);
+    } catch (e) {
+      console.log(e);
+    }
+  }
 
-    console.log('proof obj before check', proofObj);
+  // Takes any full IPFS URI and returns the CID only
+  const parseCID = (ipfsURI) => {
+    const uriSplit = ipfsURI.split('/');
+    const ipfsCID = uriSplit[uriSplit.length-1];
+    return ipfsCID;
+  }
 
+  const getProof = () => {
+    try {
+      if (leafIndex == -1) {
+        console.log('Error: value does not exist within the list');
+        return {
+          leaf: leaf,
+          errorMsg: 'Error: value does not exist within the list'
+        }
+      } 
+
+      const leaves = tree.getHexLeaves();
+      const proof = tree.getHexProof(leaves[leafIndex]);
+      const leafValueHex = toHex(leaf);
 
-    console.log(`Proof generated for ${leaf}`);
-
-    return proofObj;
-  } catch (e) {
-    console.log(e);
+      const proofObj = {
+          leafValue: leaf,
+          leafHex: leafValueHex,
+          leafHash: leaves[leafIndex],
+          proof: proof
+      };
+
+      console.log('proof obj before check', proofObj);
+      console.log(`Proof generated for ${leaf}`);
+
+      return proofObj;
+    } catch (e) {
+      console.log(e);
+    }
   }
-}
 
-const runProof = async (whitelist, leafToVerify) => {
-  await generateMerkleTree(whitelist, leafToVerify);
-  // pass in a leaf value to generate a proof
-  getLeafHashFromTreeSummary(leaf);
-  return getProof();
+  if (await fetchWhitelistFromIPFS(ipfsURIWhitelist)) {
+    await generateMerkleTree(whitelistDataResponse, leafToVerify);
+    // pass in a leaf value to generate a proof
+    getLeafHashFromTreeSummary(leaf);
+    return getProof(); 
+  } else {
+    console.log(`Error: IPFS URI Invalid`);
+  }
+  return { errorMsg: 'Error: IPFS whitelist link is invalid' }
 }
 
 router.post('/proof', async (req, res) => {