1 files changed, 47 insertions, 0 deletions
diff --git a/node_modules/cookie-signature/index.js b/node_modules/cookie-signature/index.js
new file mode 100644
index 0000000..3fbbddb
--- /dev/null
+++ b/node_modules/cookie-signature/index.js
@@ -0,0 +1,47 @@
+/**
+ * Module dependencies.
+ */
+
+var crypto = require('crypto');
+
+/**
+ * Sign the given `val` with `secret`.
+ *
+ * @param {String} val
+ * @param {String|NodeJS.ArrayBufferView|crypto.KeyObject} secret
+ * @return {String}
+ * @api private
+ */
+
+exports.sign = function(val, secret){
+  if ('string' != typeof val) throw new TypeError("Cookie value must be provided as a string.");
+  if (null == secret) throw new TypeError("Secret key must be provided.");
+  return val + '.' + crypto
+    .createHmac('sha256', secret)
+    .update(val)
+    .digest('base64')
+    .replace(/\=+$/, '');
+};
+
+/**
+ * Unsign and decode the given `input` with `secret`,
+ * returning `false` if the signature is invalid.
+ *
+ * @param {String} input
+ * @param {String|NodeJS.ArrayBufferView|crypto.KeyObject} secret
+ * @return {String|Boolean}
+ * @api private
+ */
+
+exports.unsign = function(input, secret){
+  if ('string' != typeof input) throw new TypeError("Signed cookie string must be provided.");
+  if (null == secret) throw new TypeError("Secret key must be provided.");
+  var tentativeValue = input.slice(0, input.lastIndexOf('.')),
+      expectedInput = exports.sign(tentativeValue, secret),
+      expectedBuffer = Buffer.from(expectedInput),
+      inputBuffer = Buffer.from(input);
+  return (
+    expectedBuffer.length === inputBuffer.length &&
+    crypto.timingSafeEqual(expectedBuffer, inputBuffer)
+   ) ? tentativeValue : false;
+};