use git-sha1 (for smaller bundle size)

index.js

@@ -1,19 +1,13 @@
 var bencode = require('bencode')
 var BitField = require('bitfield')
-var bufferEqual = require('buffer-equal')
-var crypto = require('crypto')
 var EventEmitter = require('events').EventEmitter
 var inherits = require('inherits')
+var sha1 = require('git-sha1')
 
 var MAX_METADATA_SIZE = 10000000 // 10MB
 var BITFIELD_GROW = 1000
 var PIECE_LENGTH = 16 * 1024
 
-// Return sha1 hash **as a buffer**
-function sha1 (buf) {
-  return crypto.createHash('sha1').update(buf).digest()
-}
-
 module.exports = function (metadata) {
 
   inherits(ut_metadata, EventEmitter)
@@ -43,6 +37,7 @@ module.exports = function (metadata) {
 
   ut_metadata.prototype.onHandshake = function (infoHash, peerId, extensions) {
     this._infoHash = infoHash
+    this._infoHashHex = infoHash.toString('hex')
   }
 
   ut_metadata.prototype.onExtendedHandshake = function (handshake) {
@@ -131,7 +126,7 @@ module.exports = function (metadata) {
     } catch (err) {}
 
     // check hash
-    if (this._infoHash && !bufferEqual(this._infoHash, sha1(metadata))) {
+    if (this._infoHashHex && this._infoHashHex !== sha1(metadata)) {
       return false
     }
 

package.json

@@ -13,7 +13,7 @@
   "dependencies": {
     "bencode": "^0.6.0",
     "bitfield": "^1.0.1",
-    "buffer-equal": "0.0.1",
+    "git-sha1": "^0.1.2",
     "inherits": "^2.0.1"
   },
   "devDependencies": {