1 files changed, 69 insertions, 0 deletions
diff --git a/node_modules/sha.js/hash.js b/node_modules/sha.js/hash.js
new file mode 100644
index 000000000..09579d2de
--- /dev/null
+++ b/node_modules/sha.js/hash.js
@@ -0,0 +1,69 @@
+// prototype class for hash functions
+function Hash (blockSize, finalSize) {
+  this._block = new Buffer(blockSize)
+  this._finalSize = finalSize
+  this._blockSize = blockSize
+  this._len = 0
+  this._s = 0
+}
+
+Hash.prototype.update = function (data, enc) {
+  if (typeof data === 'string') {
+    enc = enc || 'utf8'
+    data = new Buffer(data, enc)
+  }
+
+  var l = this._len += data.length
+  var s = this._s || 0
+  var f = 0
+  var buffer = this._block
+
+  while (s < l) {
+    var t = Math.min(data.length, f + this._blockSize - (s % this._blockSize))
+    var ch = (t - f)
+
+    for (var i = 0; i < ch; i++) {
+      buffer[(s % this._blockSize) + i] = data[i + f]
+    }
+
+    s += ch
+    f += ch
+
+    if ((s % this._blockSize) === 0) {
+      this._update(buffer)
+    }
+  }
+  this._s = s
+
+  return this
+}
+
+Hash.prototype.digest = function (enc) {
+  // Suppose the length of the message M, in bits, is l
+  var l = this._len * 8
+
+  // Append the bit 1 to the end of the message
+  this._block[this._len % this._blockSize] = 0x80
+
+  // and then k zero bits, where k is the smallest non-negative solution to the equation (l + 1 + k) === finalSize mod blockSize
+  this._block.fill(0, this._len % this._blockSize + 1)
+
+  if (l % (this._blockSize * 8) >= this._finalSize * 8) {
+    this._update(this._block)
+    this._block.fill(0)
+  }
+
+  // to this append the block which is equal to the number l written in binary
+  // TODO: handle case where l is > Math.pow(2, 29)
+  this._block.writeInt32BE(l, this._blockSize - 4)
+
+  var hash = this._update(this._block) || this._hash()
+
+  return enc ? hash.toString(enc) : hash
+}
+
+Hash.prototype._update = function () {
+  throw new Error('_update must be implemented by subclass')
+}
+
+module.exports = Hash