first commit

app_vue/node_modules/node-forge/lib/mgf1.js

@@ -0,0 +1,57 @@
+/**
+ * Javascript implementation of mask generation function MGF1.
+ *
+ * @author Stefan Siegl
+ * @author Dave Longley
+ *
+ * Copyright (c) 2012 Stefan Siegl <stesie@brokenpipe.de>
+ * Copyright (c) 2014 Digital Bazaar, Inc.
+ */
+var forge = require('./forge');
+require('./util');
+
+forge.mgf = forge.mgf || {};
+var mgf1 = module.exports = forge.mgf.mgf1 = forge.mgf1 = forge.mgf1 || {};
+
+/**
+ * Creates a MGF1 mask generation function object.
+ *
+ * @param md the message digest API to use (eg: forge.md.sha1.create()).
+ *
+ * @return a mask generation function object.
+ */
+mgf1.create = function(md) {
+  var mgf = {
+    /**
+     * Generate mask of specified length.
+     *
+     * @param {String} seed The seed for mask generation.
+     * @param maskLen Number of bytes to generate.
+     * @return {String} The generated mask.
+     */
+    generate: function(seed, maskLen) {
+      /* 2. Let T be the empty octet string. */
+      var t = new forge.util.ByteBuffer();
+
+      /* 3. For counter from 0 to ceil(maskLen / hLen), do the following: */
+      var len = Math.ceil(maskLen / md.digestLength);
+      for(var i = 0; i < len; i++) {
+        /* a. Convert counter to an octet string C of length 4 octets */
+        var c = new forge.util.ByteBuffer();
+        c.putInt32(i);
+
+        /* b. Concatenate the hash of the seed mgfSeed and C to the octet
+         * string T: */
+        md.start();
+        md.update(seed + c.getBytes());
+        t.putBuffer(md.digest());
+      }
+
+      /* Output the leading maskLen octets of T as the octet string mask. */
+      t.truncate(t.length() - maskLen);
+      return t.getBytes();
+    }
+  };
+
+  return mgf;
+};