1 files changed, 40 insertions, 0 deletions
diff --git a/app/assets/javascripts/authentication/u2f/util.js b/app/assets/javascripts/authentication/u2f/util.js
new file mode 100644
index 00000000000..b706481c02f
--- /dev/null
+++ b/app/assets/javascripts/authentication/u2f/util.js
@@ -0,0 +1,40 @@
+function isOpera(userAgent) {
+  return userAgent.indexOf('Opera') >= 0 || userAgent.indexOf('OPR') >= 0;
+}
+
+function getOperaVersion(userAgent) {
+  const match = userAgent.match(/OPR[^0-9]*([0-9]+)[^0-9]+/);
+  return match ? parseInt(match[1], 10) : false;
+}
+
+function isChrome(userAgent) {
+  return userAgent.indexOf('Chrom') >= 0 && !isOpera(userAgent);
+}
+
+function getChromeVersion(userAgent) {
+  const match = userAgent.match(/Chrom(?:e|ium)\/([0-9]+)\./);
+  return match ? parseInt(match[1], 10) : false;
+}
+
+export function canInjectU2fApi(userAgent) {
+  const isSupportedChrome = isChrome(userAgent) && getChromeVersion(userAgent) >= 41;
+  const isSupportedOpera = isOpera(userAgent) && getOperaVersion(userAgent) >= 40;
+  const isMobile =
+    userAgent.indexOf('droid') >= 0 ||
+    userAgent.indexOf('CriOS') >= 0 ||
+    /\b(iPad|iPhone|iPod)(?=;)/.test(userAgent);
+  return (isSupportedChrome || isSupportedOpera) && !isMobile;
+}
+
+export default function importU2FLibrary() {
+  if (window.u2f) {
+    return Promise.resolve(window.u2f);
+  }
+
+  const userAgent = typeof navigator !== 'undefined' ? navigator.userAgent : '';
+  if (canInjectU2fApi(userAgent) || (gon && gon.test_env)) {
+    return import(/* webpackMode: "eager" */ 'vendor/u2f').then(() => window.u2f);
+  }
+
+  return Promise.reject();
+}