pbkdf2

Author: dominictarr

index.js

@@ -29,6 +29,11 @@ function each(a, f) {
     f(a[i], i)
 }
 
+var p = require('./pbkdf2')(exports.createHmac)
+exports.pbkdf2 = p.pbkdf2
+exports.pbkdf2Sync = p.pbkdf2Sync
+
+
 // the least I can do is make error messages for the rest of the node.js/crypto api.
 each(['createCredentials'
 , 'createCipher'
@@ -38,7 +43,7 @@ each(['createCredentials'
 , 'createSign'
 , 'createVerify'
 , 'createDiffieHellman'
-, 'pbkdf2'], function (name) {
+], function (name) {
   exports[name] = function () {
     error('sorry,', name, 'is not implemented yet')
   }

pbkdf2.js

@@ -0,0 +1,73 @@
+// JavaScript PBKDF2 Implementation
+// Based on http://git.io/qsv2zw
+// Licensed under LGPL v3
+// Copyright (c) 2013 jduncanator
+
+var Buffer = require('buffer').Buffer
+
+var blocksize = 64
+var zeroBuffer = new Buffer(blocksize); zeroBuffer.fill(0)
+
+module.exports = function (createHmac, exports) {
+  exports = exports || {}
+
+  exports.pbkdf2 = function(password, salt, iterations, keylen, callback) {
+    if('function' !== typeof callback)
+      throw new Error('No callback provided to pbkdf2');
+    setTimeout(function () {
+      cb(null, exports.pbkdf2(password, salt, iterations, keylen))
+    })
+  }
+
+  exports.pbkdf2Sync = function(password, salt, iterations, keylen) {
+    if('number' !== typeof iterations)
+      throw new TypeError('Iterations not a number')
+    if(iterations < 0)
+      throw new TypeError('Bad iterations')
+    if('number' !== typeof keylen)
+      throw new TypeError('Key length not a number')
+    if(keylen < 0)
+      throw new TypeError('Bad key length')
+
+    var HMAC;
+    var cplen, p = 0, i = 1, itmp = new Buffer(4), digtmp;
+    var out = new Buffer(keylen);
+    out.fill(0);
+    while(keylen) {
+      if(keylen > 20)
+        cplen = 20;
+      else
+        cplen = keylen;
+
+      /* We are unlikely to ever use more than 256 blocks (5120 bits!)
+         * but just in case...
+         */
+        itmp[0] = (i >> 24) & 0xff;
+        itmp[1] = (i >> 16) & 0xff;
+          itmp[2] = (i >> 8) & 0xff;
+          itmp[3] = i & 0xff;
+
+          HMAC = createHmac('sha1', password);
+          HMAC.update(salt)
+          HMAC.update(itmp);
+        digtmp = HMAC.digest();
+        digtmp.copy(out, p, 0, cplen);
+
+        for(var j = 1; j < iterations; j++) {
+          HMAC = createHmac('sha1', password);
+          HMAC.update(digtmp);
+          digtmp = HMAC.digest();
+          for(var k = 0; k < cplen; k++) {
+            out[k] ^= digtmp[k];
+          }
+        }
+      keylen -= cplen;
+      i++;
+      p += cplen;
+    }
+
+    return out;
+  }
+
+  return exports
+}