1 files changed, 68 insertions, 0 deletions
diff --git a/node_modules/create-hmac/browser.js b/node_modules/create-hmac/browser.js
new file mode 100644
index 000000000..b610781b2
--- /dev/null
+++ b/node_modules/create-hmac/browser.js
@@ -0,0 +1,68 @@
+'use strict';
+var createHash = require('create-hash/browser');
+var inherits = require('inherits')
+
+var Transform = require('stream').Transform
+
+var ZEROS = new Buffer(128)
+ZEROS.fill(0)
+
+function Hmac(alg, key) {
+  Transform.call(this)
+  alg = alg.toLowerCase()
+  if (typeof key === 'string') {
+    key = new Buffer(key)
+  }
+
+  var blocksize = (alg === 'sha512' || alg === 'sha384') ? 128 : 64
+
+  this._alg = alg
+  this._key = key
+
+  if (key.length > blocksize) {
+    key = createHash(alg).update(key).digest()
+
+  } else if (key.length < blocksize) {
+    key = Buffer.concat([key, ZEROS], blocksize)
+  }
+
+  var ipad = this._ipad = new Buffer(blocksize)
+  var opad = this._opad = new Buffer(blocksize)
+
+  for (var i = 0; i < blocksize; i++) {
+    ipad[i] = key[i] ^ 0x36
+    opad[i] = key[i] ^ 0x5C
+  }
+
+  this._hash = createHash(alg).update(ipad)
+}
+
+inherits(Hmac, Transform)
+
+Hmac.prototype.update = function (data, enc) {
+  this._hash.update(data, enc)
+
+  return this
+}
+
+Hmac.prototype._transform = function (data, _, next) {
+  this._hash.update(data)
+
+  next()
+}
+
+Hmac.prototype._flush = function (next) {
+  this.push(this.digest())
+
+  next()
+}
+
+Hmac.prototype.digest = function (enc) {
+  var h = this._hash.digest()
+
+  return createHash(this._alg).update(this._opad).update(h).digest(enc)
+}
+
+module.exports = function createHmac(alg, key) {
+  return new Hmac(alg, key)
+}