Merge pull request #81 from runtimejs/tmp-rng

Random API and RNG

Author: iefserge

js/.eslintignore

@@ -0,0 +1 @@
+deps/

js/core/index.js

@@ -19,13 +19,15 @@ console.log = isolate.log;
 var resources = require('./resources');
 require('./polyfill');
 
+var random = require('./random');
 var keyboard = require('./keyboard');
 var ps2 = require('./ps2');
 var pci = require('./pci');
 var net = require('./net');
 var stdio = require('./stdio');
 
 function Runtime() {
+  this.random = random;
   this.keyboard = keyboard;
   this.pci = pci;
   this.ps2 = ps2;

js/core/random/entropy-source.js

@@ -0,0 +1,39 @@
+// Copyright 2015 runtime.js project authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+'use strict';
+
+class EntropySource {
+  constructor(name) {
+    this._name = name || '';
+    this.ongetbytes = null;
+  }
+
+  getName() {
+    return this._name;
+  }
+
+  /**
+   * Request randomness from this entropy source
+   */
+  getBytes(u8, cb) {
+    if (!this.ongetbytes) {
+      throw new Error('entropy source was not initialized');
+    }
+
+    this.ongetbytes(u8, cb);
+  }
+}
+
+module.exports = EntropySource;

js/core/random/index.js

@@ -0,0 +1,98 @@
+// Copyright 2015 runtime.js project authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+'use strict';
+var isaac = require('./isaac-wrapper');
+var EntropySource = require('./entropy-source');
+var sources = require('./sources');
+var typeutils = require('typeutils');
+var getDefaultSource = sources.getDefaultSource;
+require('./js-random-source');
+
+exports.EntropySource = EntropySource;
+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 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.getTrueRandomValues = function(value, cb) {
+  var u8 = null;
+  if (typeutils.isNumber(value)) {
+    u8 = new Uint8Array(value);
+  }
+
+  if (value instanceof Uint8Array) {
+    u8 = value;
+  }
+
+  if (!u8) {
+    throw new Error('getTrueRandomValues: argument 0 is not a number or Uint8Array');
+  }
+
+  if (u8.length === 0) {
+    throw new Error('getTrueRandomValues: buffer length must be greater than 0');
+  }
+
+  if (!typeutils.isFunction(cb)) {
+    throw new Error('getTrueRandomValues: argument 1 is not a function');
+  }
+
+  var defaultSource = getDefaultSource();
+  if (!defaultSource) {
+    throw new Error('getTrueRandomValues: no entropy source available');
+  }
+
+  defaultSource.getBytes(u8, function() {
+    isaac.seed(u8);
+    cb(u8);
+  });
+};
+
+/**
+ * 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.getRandomValues = function(value) {
+  var u8 = null;
+  if (typeutils.isNumber(value)) {
+    u8 = new Uint8Array(value);
+  }
+
+  if (value instanceof Uint8Array) {
+    u8 = value;
+  }
+
+  if (!u8) {
+    throw new Error('getRandomValues: argument 0 is not a number or Uint8Array');
+  }
+
+  if (u8.length === 0) {
+    throw new Error('getRandomValues: buffer length must be greater than 0');
+  }
+
+  for (var i = 0; i < u8.length; i++) {
+    u8[i] = isaac.getByte();
+  }
+
+  return u8;
+};

js/core/random/isaac-wrapper.js

@@ -0,0 +1,34 @@
+// Copyright 2015 runtime.js project authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+'use strict';
+
+var isaac = require('../../deps/isaac/isaac');
+
+// isaac.js returns crazy numbers, both positive and negative.
+// This function is called on an isaac.rand() call,
+// It gets the number to qualify for all of the following:
+//  * Positive,
+//  * Whole number,
+//  * 0 < n < 256
+// This ensures the numbers are similar to the numbers
+// generated by VirtioRNG.
+function isaacToUint8(n) {
+  return (n >>> 0) & 0xff;
+}
+
+exports.seed = isaac.seed;
+exports.getByte = function() {
+  return isaacToUint8(isaac.rand());
+};

js/core/random/js-random-source.js

@@ -0,0 +1,30 @@
+// Copyright 2015 runtime.js project authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+'use strict';
+var isaac = require('./isaac-wrapper');
+var EntropySource = require('./entropy-source');
+var sources = require('./sources');
+
+// Low quality entropy source based on Math.random() seed
+// and isaac CSPRNG
+var source = new EntropySource('js-random');
+source.ongetbytes = function(u8, cb) {
+  for (var i = 0; i < u8.length; i++) {
+    u8[i] = isaac.getByte();
+  }
+  cb();
+};
+
+sources.addEntropySource(source);

js/core/random/sources.js

@@ -0,0 +1,34 @@
+// Copyright 2015 runtime.js project authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// 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;
+};
+
+exports.getDefaultSource = function() {
+  return defaultSource;
+};

js/deps/isaac/LICENSE.isaac

@@ -0,0 +1,19 @@
+Copyright (c) 2012 Yves-Marie K. Rinquin
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.