fix(node): older versions of node@4 do not support base64buffer strin…

…g parsing

Fixes: npm/npm#16809

index.js

@@ -1,5 +1,7 @@
 'use strict'
 
+const Buffer = require('safe-buffer').Buffer
+
 const crypto = require('crypto')
 const Transform = require('stream').Transform
 
@@ -31,7 +33,7 @@ class Hash {
     this.options = rawOpts ? rawOpts.slice(1).split('?') : []
   }
   hexDigest () {
-    return this.digest && bufFrom(this.digest, 'base64').toString('hex')
+    return this.digest && Buffer.from(this.digest, 'base64').toString('hex')
   }
   toJSON () {
     return this.toString()
@@ -154,7 +156,7 @@ function fromHex (hexDigest, algorithm, opts) {
   : ''
   return parse(
     `${algorithm}-${
-      bufFrom(hexDigest, 'hex').toString('base64')
+      Buffer.from(hexDigest, 'hex').toString('base64')
     }${optString}`, opts
   )
 }
@@ -332,7 +334,3 @@ function getPrioritizedHash (algo1, algo2) {
   ? algo1
   : algo2
 }
-
-function bufFrom (data, enc) {
-  return Buffer.from ? Buffer.from(data, enc) : new Buffer(data, enc)
-}

package.json

@@ -36,7 +36,9 @@
     "twitter": "maybekatz"
   },
   "license": "CC0-1.0",
-  "dependencies": {},
+  "dependencies": {
+    "safe-buffer": "^5.0.1"
+  },
   "devDependencies": {
     "nyc": "^10.3.2",
     "standard": "^9.0.2",