Added crypto quality random number generators for Node.js and browser environment if available

4 files changed, 54 insertions, 19 deletions

diff --git a/src/library_uuid.js b/src/library_uuid.js
index 0c1bdf91..cce0a4f8 100644
--- a/src/library_uuid.js
+++ b/src/library_uuid.js
@@ -27,12 +27,30 @@ mergeInto(LibraryManager.library, {
   // tweaked slightly in order to use the 'compact' UUID form used by libuuid.
   uuid_generate: function(out) {
     // void uuid_generate(uuid_t out);
-    var uuid = new Array(16);
-    var d = new Date().getTime();
-    for (var i = 0; i < 16; i++) {
-      var r = (d + Math.random()*256)%256 | 0;
-      d = Math.floor(d/256);
-      uuid[i] = r;
+    var uuid = null;
+
+    if (ENVIRONMENT_IS_NODE) {
+      // If Node.js try to use crypto.randomBytes
+      try {
+        var rb = require('crypto').randomBytes;
+        uuid = rb(16);
+      } catch(e) {}
+    } else if (typeof(window.crypto) != 'undefined' && 
+               typeof(window.crypto.getRandomValues) != 'undefined') {
+      // If crypto.getRandomValues is available try to use it.
+      uuid = new Uint8Array(16);
+      window.crypto.getRandomValues(uuid);
+    }
+
+    // Fall back to Math.random if a higher quality random number generator is not available.
+    if (!uuid) {
+      uuid = new Array(16);
+      var d = new Date().getTime();
+      for (var i = 0; i < 16; i++) {
+        var r = (d + Math.random()*256)%256 | 0;
+        d = Math.floor(d/256);
+        uuid[i] = r;
+      }
     }
 
     uuid[6] = (uuid[6] & 0x0F) | 0x40;
diff --git a/tests/test_browser.py b/tests/test_browser.py
index 920c6f8c..3d344c14 100644
--- a/tests/test_browser.py
+++ b/tests/test_browser.py
@@ -1717,3 +1717,23 @@ keydown(100);keyup(100); // trigger the end
     assert 'argv[3]: 3' in stdout
     assert 'hello, world!' in stdout
     assert 'hello, error stream!' in stderr
+
+  def test_uuid(self):
+    # Run with ./runner.py browser.test_uuid
+    # We run this test in Node/SPIDERMONKEY and browser environments because we try to make use of
+    # high quality crypto random number generators such as crypto.getRandomValues or randomBytes (if available).
+
+    # First run tests in Node and/or SPIDERMONKEY using run_js
+    Popen([PYTHON, EMCC, path_from_root('tests', 'uuid', 'test.c'), '-o', path_from_root('tests', 'uuid', 'test.js')], stdout=PIPE, stderr=PIPE).communicate()
+
+    out = run_js(path_from_root('tests', 'uuid', 'test.js'), full_output=True)
+    print out
+
+    # Tidy up files that might have been created by this test.
+    try_delete(path_from_root('tests', 'uuid', 'test.js'))
+    try_delete(path_from_root('tests', 'uuid', 'test.js.map'))
+
+    # Now run test in browser
+    self.btest(path_from_root('tests', 'uuid', 'test.c'), '1')
+
+
diff --git a/tests/test_other.py b/tests/test_other.py
index f229fef1..c75362af 100644
--- a/tests/test_other.py
+++ b/tests/test_other.py
@@ -2197,14 +2197,3 @@ mergeInto(LibraryManager.library, {
     process.communicate()
     assert(os.path.isfile(outdir + 'hello_world.obj'))
 
-  def test_uuid(self):
-    # Run with ./runner.py other.test_uuid
-    Popen([PYTHON, EMCC, path_from_root('tests', 'uuid', 'test.c'), '-o', path_from_root('tests', 'uuid', 'test.js')], stdout=PIPE, stderr=PIPE).communicate()
-
-    out = run_js(path_from_root('tests', 'uuid', 'test.js'), full_output=True)
-    print out
-
-    # Tidy up files that might have been created by this test.
-    try_delete(path_from_root('tests', 'uuid', 'test.js'))
-    try_delete(path_from_root('tests', 'uuid', 'test.js.map'))
-
diff --git a/tests/uuid/test.c b/tests/uuid/test.c
index ea3b116c..dc2c6589 100644
--- a/tests/uuid/test.c
+++ b/tests/uuid/test.c
@@ -1,8 +1,9 @@
-
 #include <uuid/uuid.h>
 #include <assert.h>
+#include <ctype.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <emscripten.h>
 
 int isUUID(char* p, int upper) {
     char* p1 = p;
@@ -56,6 +57,13 @@ int main() {
 
     assert(uuid_is_null(uuid) == 1);
 
-    return 0;
+    // The following lets the browser test exit cleanly.
+    int result = 1;
+    #if EMSCRIPTEN
+        #ifdef REPORT_RESULT
+            REPORT_RESULT();
+        #endif
+    #endif
+    exit(0);
 }