From 071a0050da1c235dc71f5818eda8a32043c5483f Mon Sep 17 00:00:00 2001
From: Richard Schneider <makaretu@gmail.com>
Date: Tue, 26 Jun 2018 15:05:06 +1200
Subject: [PATCH] fix: use multihashing-async

---
 package.json |  2 +-
 src/util.js  | 26 ++++++++++++--------------
 2 files changed, 13 insertions(+), 15 deletions(-)

diff --git a/package.json b/package.json
index 1d4b45b..a507310 100644
--- a/package.json
+++ b/package.json
@@ -35,8 +35,8 @@
   "dependencies": {
     "cids": "~0.5.2",
     "dirty-chai": "^2.0.1",
-    "hash.js": "^1.1.3",
     "multihashes": "~0.4.12",
+    "multihashing-async": "~0.5.1",
     "zcash-bitcore-lib": "^0.13.20-rc3"
   },
   "devDependencies": {
diff --git a/src/util.js b/src/util.js
index 1b0136c..7aaad93 100644
--- a/src/util.js
+++ b/src/util.js
@@ -3,7 +3,8 @@
 const ZcashBitcoreBlock = require('zcash-bitcore-lib').Block
 const CID = require('cids')
 const multihashes = require('multihashes')
-const sha256 = require('hash.js/lib/hash/sha/256')
+const multihashing = require('multihashing-async')
+const waterfall = require('async/waterfall')
 
 /**
  * @callback SerializeCallback
@@ -76,19 +77,16 @@ const cid = (dagNode, options, callback) => {
     options = {}
   }
   options = options || {}
-  let err = null
-  let cid
-  try {
-    // Zcash double hashes
-    const firstHash = sha256().update(dagNode.header.toBuffer(true)).digest()
-    const headerHash = sha256().update(Buffer.from(firstHash)).digest()
-
-    cid = hashToCid(Buffer.from(headerHash))
-  } catch (cidError) {
-    err = cidError
-  } finally {
-    callback(err, cid)
-  }
+  waterfall([
+    (cb) => {
+      try {
+        multihashing(dagNode.header.toBuffer(true), 'dbl-sha2-256', cb)
+      } catch (err) {
+        cb(err)
+      }
+    },
+    (mh, cb) => cb(null, new CID(1, 'zcash-block', mh))
+  ], callback)
 }
 
 // Convert a Zcash hash (as Buffer) to a CID