Rename getPseudoRandomValues to getRandomValues and seed it on startup

Author: iefserge

js/core/random/index.js

@@ -26,13 +26,14 @@ exports.addEntropySource = sources.addEntropySource;
 /**
  * Request random bytes from the best available entropy source. This
  * function is asynchronous bacause it might take some time to gather
- * enough entropy from the source. This is similar to /dev/random
- * in Unix.
+ * enough entropy from the source. This might use /dev/random as a backend
+ * in KVM and might be extremely slow depending on the buffer size and
+ * the amount of available entropy.
  *
  * @param {number|Uint8Array} value Number of bytes to request or buffer to fill
  * @param {function} cb Callback with the resulting Uint8Array buffer argument
  */
-exports.getRandomValues = function(value, cb) {
+exports.getTrueRandomValues = function(value, cb) {
   var u8 = null;
   if (typeutils.isNumber(value)) {
     u8 = new Uint8Array(value);
@@ -43,20 +44,20 @@ exports.getRandomValues = function(value, cb) {
   }
 
   if (!u8) {
-    throw new Error('getRandomValues: argument 0 is not a number or Uint8Array');
+    throw new Error('getTrueRandomValues: argument 0 is not a number or Uint8Array');
   }
 
   if (u8.length === 0) {
-    throw new Error('getRandomValues: buffer length must be greater than 0');
+    throw new Error('getTrueRandomValues: buffer length must be greater than 0');
   }
 
   if (!typeutils.isFunction(cb)) {
-    throw new Error('getRandomValues: argument 1 is not a function');
+    throw new Error('getTrueRandomValues: argument 1 is not a function');
   }
 
   var defaultSource = getDefaultSource();
   if (!defaultSource) {
-    throw new Error('getRandomValues: no entropy source available');
+    throw new Error('getTrueRandomValues: no entropy source available');
   }
 
   defaultSource.getBytes(u8, function() {
@@ -66,14 +67,12 @@ exports.getRandomValues = function(value, cb) {
 };
 
 /**
- * Request random bytes from the immediately available entropy source. This
- * function is synchronous, but the output may contain less entropy than
- * getRandomValues() output. This is similar to Unix's /dev/urandom.
+ * Request random bytes from the CSPRNG seeded with enough entropy.
  *
  * @param {number|Uint8Array} value Number of bytes to request or buffer to fill
  * @return {Uint8Array} Buffer filled with random data
  */
-exports.getPseudoRandomValues = function(value) {
+exports.getRandomValues = function(value) {
   var u8 = null;
   if (typeutils.isNumber(value)) {
     u8 = new Uint8Array(value);
@@ -84,11 +83,11 @@ exports.getPseudoRandomValues = function(value) {
   }
 
   if (!u8) {
-    throw new Error('getPseudoRandomValues: argument 0 is not a number or Uint8Array');
+    throw new Error('getRandomValues: argument 0 is not a number or Uint8Array');
   }
 
   if (u8.length === 0) {
-    throw new Error('getPseudoRandomValues: buffer length must be greater than 0');
+    throw new Error('getRandomValues: buffer length must be greater than 0');
   }
 
   for (var i = 0; i < u8.length; i++) {

js/core/random/sources.js

@@ -13,15 +13,20 @@
 // limitations under the License.
 
 'use strict';
+var isaac = require('./isaac-wrapper');
 var defaultSource = null;
 var availableSources = Object.create(null);
 
 exports.addEntropySource = function(source) {
   availableSources[source.getName()] = source;
 
+  source.getBytes(new Uint8Array(8), function(u8) {
+    isaac.seed(u8);
+    console.log('[random] using entropy source', source.getName());
+  });
+
   // Set this source as the default one
   defaultSource = source;
-  console.log('[random] using entropy source', defaultSource.getName());
 };
 
 exports.getDefaultSource = function() {

js/test/unit/random/index.js

@@ -37,33 +37,33 @@ test('EntropySource', function(t) {
   });
 });
 
-test('getRandomValues buffer', function(t) {
+test('getTrueRandomValues buffer', function(t) {
   t.timeoutAfter(1000);
   var u8 = new Uint8Array([0, 0, 0]);
-  runtime.random.getRandomValues(u8, function(u8out) {
+  runtime.random.getTrueRandomValues(u8, function(u8out) {
     t.equal(u8, u8out);
     t.end();
   });
 });
 
-test('getRandomValues length', function(t) {
+test('getTrueRandomValues length', function(t) {
   t.timeoutAfter(1000);
-  runtime.random.getRandomValues(10, function(u8) {
+  runtime.random.getTrueRandomValues(4, function(u8) {
     t.ok(u8 instanceof Uint8Array);
-    t.equal(u8.length, 10);
+    t.equal(u8.length, 4);
     t.end();
   });
 });
 
-test('getPseudoRandomValues buffer', function(t) {
+test('getRandomValues buffer', function(t) {
   var u8 = new Uint8Array([0, 0, 0]);
-  var u8out = runtime.random.getPseudoRandomValues(u8);
+  var u8out = runtime.random.getRandomValues(u8);
   t.equal(u8, u8out);
   t.end();
 });
 
-test('getPseudoRandomValues length', function(t) {
-  var u8 = runtime.random.getPseudoRandomValues(10);
+test('getRandomValues length', function(t) {
+  var u8 = runtime.random.getRandomValues(10);
   t.ok(u8 instanceof Uint8Array);
   t.equal(u8.length, 10);
   t.end();