1 files changed, 120 insertions, 0 deletions
diff --git a/app/assets/javascripts/authentication/webauthn/util.js b/app/assets/javascripts/authentication/webauthn/util.js
new file mode 100644
index 00000000000..5f06c000afe
--- /dev/null
+++ b/app/assets/javascripts/authentication/webauthn/util.js
@@ -0,0 +1,120 @@
+export function supported() {
+  return Boolean(
+    navigator.credentials &&
+      navigator.credentials.create &&
+      navigator.credentials.get &&
+      window.PublicKeyCredential,
+  );
+}
+
+export function isHTTPS() {
+  return window.location.protocol.startsWith('https');
+}
+
+export const FLOW_AUTHENTICATE = 'authenticate';
+export const FLOW_REGISTER = 'register';
+
+// adapted from https://stackoverflow.com/a/21797381/8204697
+function base64ToBuffer(base64) {
+  const binaryString = window.atob(base64);
+  const len = binaryString.length;
+  const bytes = new Uint8Array(len);
+  for (let i = 0; i < len; i += 1) {
+    bytes[i] = binaryString.charCodeAt(i);
+  }
+  return bytes.buffer;
+}
+
+// adapted from https://stackoverflow.com/a/9458996/8204697
+function bufferToBase64(buffer) {
+  if (typeof buffer === 'string') {
+    return buffer;
+  }
+
+  let binary = '';
+  const bytes = new Uint8Array(buffer);
+  const len = bytes.byteLength;
+  for (let i = 0; i < len; i += 1) {
+    binary += String.fromCharCode(bytes[i]);
+  }
+  return window.btoa(binary);
+}
+
+/**
+ * Returns a copy of the given object with the id property converted to buffer
+ *
+ * @param {Object} param
+ */
+function convertIdToBuffer({ id, ...rest }) {
+  return {
+    ...rest,
+    id: base64ToBuffer(id),
+  };
+}
+
+/**
+ * Returns a copy of the given array with all `id`s of the items converted to buffer
+ *
+ * @param {Array} items
+ */
+function convertIdsToBuffer(items) {
+  return items.map(convertIdToBuffer);
+}
+
+/**
+ * Returns an object with keys of the given props, and values from the given object converted to base64
+ *
+ * @param {String} obj
+ * @param {Array} props
+ */
+function convertPropertiesToBase64(obj, props) {
+  return props.reduce(
+    (acc, property) => Object.assign(acc, { [property]: bufferToBase64(obj[property]) }),
+    {},
+  );
+}
+
+export function convertGetParams({ allowCredentials, challenge, ...rest }) {
+  return {
+    ...rest,
+    ...(allowCredentials ? { allowCredentials: convertIdsToBuffer(allowCredentials) } : {}),
+    challenge: base64ToBuffer(challenge),
+  };
+}
+
+export function convertGetResponse(webauthnResponse) {
+  return {
+    type: webauthnResponse.type,
+    id: webauthnResponse.id,
+    rawId: bufferToBase64(webauthnResponse.rawId),
+    response: convertPropertiesToBase64(webauthnResponse.response, [
+      'clientDataJSON',
+      'authenticatorData',
+      'signature',
+      'userHandle',
+    ]),
+    clientExtensionResults: webauthnResponse.getClientExtensionResults(),
+  };
+}
+
+export function convertCreateParams({ challenge, user, excludeCredentials, ...rest }) {
+  return {
+    ...rest,
+    challenge: base64ToBuffer(challenge),
+    user: convertIdToBuffer(user),
+    ...(excludeCredentials ? { excludeCredentials: convertIdsToBuffer(excludeCredentials) } : {}),
+  };
+}
+
+export function convertCreateResponse(webauthnResponse) {
+  return {
+    type: webauthnResponse.type,
+    id: webauthnResponse.id,
+    rawId: bufferToBase64(webauthnResponse.rawId),
+    clientExtensionResults: webauthnResponse.getClientExtensionResults(),
+    response: convertPropertiesToBase64(webauthnResponse.response, [
+      'clientDataJSON',
+      'attestationObject',
+    ]),
+  };
+}