1 files changed, 194 insertions, 0 deletions
diff --git a/web_src/js/features/user-auth-webauthn.js b/web_src/js/features/user-auth-webauthn.js
new file mode 100644
index 0000000..6dfbb4d
--- /dev/null
+++ b/web_src/js/features/user-auth-webauthn.js
@@ -0,0 +1,194 @@
+import {encodeURLEncodedBase64, decodeURLEncodedBase64} from '../utils.js';
+import {showElem} from '../utils/dom.js';
+import {GET, POST} from '../modules/fetch.js';
+
+const {appSubUrl} = window.config;
+
+export async function initUserAuthWebAuthn() {
+  const elPrompt = document.querySelector('.user.signin.webauthn-prompt');
+  if (!elPrompt) {
+    return;
+  }
+
+  if (!detectWebAuthnSupport()) {
+    return;
+  }
+
+  const res = await GET(`${appSubUrl}/user/webauthn/assertion`);
+  if (res.status !== 200) {
+    webAuthnError('unknown');
+    return;
+  }
+  const options = await res.json();
+  options.publicKey.challenge = decodeURLEncodedBase64(options.publicKey.challenge);
+  for (const cred of options.publicKey.allowCredentials) {
+    cred.id = decodeURLEncodedBase64(cred.id);
+  }
+  try {
+    const credential = await navigator.credentials.get({
+      publicKey: options.publicKey,
+    });
+    await verifyAssertion(credential);
+  } catch (err) {
+    if (!options.publicKey.extensions?.appid) {
+      webAuthnError('general', err.message);
+      return;
+    }
+    delete options.publicKey.extensions.appid;
+    try {
+      const credential = await navigator.credentials.get({
+        publicKey: options.publicKey,
+      });
+      await verifyAssertion(credential);
+    } catch (err) {
+      webAuthnError('general', err.message);
+    }
+  }
+}
+
+async function verifyAssertion(assertedCredential) {
+  // Move data into Arrays in case it is super long
+  const authData = new Uint8Array(assertedCredential.response.authenticatorData);
+  const clientDataJSON = new Uint8Array(assertedCredential.response.clientDataJSON);
+  const rawId = new Uint8Array(assertedCredential.rawId);
+  const sig = new Uint8Array(assertedCredential.response.signature);
+  const userHandle = new Uint8Array(assertedCredential.response.userHandle);
+
+  const res = await POST(`${appSubUrl}/user/webauthn/assertion`, {
+    data: {
+      id: assertedCredential.id,
+      rawId: encodeURLEncodedBase64(rawId),
+      type: assertedCredential.type,
+      clientExtensionResults: assertedCredential.getClientExtensionResults(),
+      response: {
+        authenticatorData: encodeURLEncodedBase64(authData),
+        clientDataJSON: encodeURLEncodedBase64(clientDataJSON),
+        signature: encodeURLEncodedBase64(sig),
+        userHandle: encodeURLEncodedBase64(userHandle),
+      },
+    },
+  });
+  if (res.status === 500) {
+    webAuthnError('unknown');
+    return;
+  } else if (res.status !== 200) {
+    webAuthnError('unable-to-process');
+    return;
+  }
+  const reply = await res.json();
+
+  window.location.href = reply?.redirect ?? `${appSubUrl}/`;
+}
+
+async function webauthnRegistered(newCredential) {
+  const attestationObject = new Uint8Array(newCredential.response.attestationObject);
+  const clientDataJSON = new Uint8Array(newCredential.response.clientDataJSON);
+  const rawId = new Uint8Array(newCredential.rawId);
+
+  const res = await POST(`${appSubUrl}/user/settings/security/webauthn/register`, {
+    data: {
+      id: newCredential.id,
+      rawId: encodeURLEncodedBase64(rawId),
+      type: newCredential.type,
+      response: {
+        attestationObject: encodeURLEncodedBase64(attestationObject),
+        clientDataJSON: encodeURLEncodedBase64(clientDataJSON),
+      },
+    },
+  });
+
+  if (res.status === 409) {
+    webAuthnError('duplicated');
+    return;
+  } else if (res.status !== 201) {
+    webAuthnError('unknown');
+    return;
+  }
+
+  window.location.reload();
+}
+
+function webAuthnError(errorType, message) {
+  const elErrorMsg = document.getElementById(`webauthn-error-msg`);
+
+  if (errorType === 'general') {
+    elErrorMsg.textContent = message || 'unknown error';
+  } else {
+    const elTypedError = document.querySelector(`#webauthn-error [data-webauthn-error-msg=${errorType}]`);
+    if (elTypedError) {
+      elErrorMsg.textContent = `${elTypedError.textContent}${message ? ` ${message}` : ''}`;
+    } else {
+      elErrorMsg.textContent = `unknown error type: ${errorType}${message ? ` ${message}` : ''}`;
+    }
+  }
+
+  showElem('#webauthn-error');
+}
+
+function detectWebAuthnSupport() {
+  if (!window.isSecureContext) {
+    webAuthnError('insecure');
+    return false;
+  }
+
+  if (typeof window.PublicKeyCredential !== 'function') {
+    webAuthnError('browser');
+    return false;
+  }
+
+  return true;
+}
+
+export function initUserAuthWebAuthnRegister() {
+  const elRegister = document.getElementById('register-webauthn');
+  if (!elRegister) {
+    return;
+  }
+  if (!detectWebAuthnSupport()) {
+    elRegister.disabled = true;
+    return;
+  }
+  elRegister.addEventListener('click', async (e) => {
+    e.preventDefault();
+    await webAuthnRegisterRequest();
+  });
+}
+
+async function webAuthnRegisterRequest() {
+  const elNickname = document.getElementById('nickname');
+
+  const formData = new FormData();
+  formData.append('name', elNickname.value);
+
+  const res = await POST(`${appSubUrl}/user/settings/security/webauthn/request_register`, {
+    data: formData,
+  });
+
+  if (res.status === 409) {
+    webAuthnError('duplicated');
+    return;
+  } else if (res.status !== 200) {
+    webAuthnError('unknown');
+    return;
+  }
+
+  const options = await res.json();
+  elNickname.closest('div.field').classList.remove('error');
+
+  options.publicKey.challenge = decodeURLEncodedBase64(options.publicKey.challenge);
+  options.publicKey.user.id = decodeURLEncodedBase64(options.publicKey.user.id);
+  if (options.publicKey.excludeCredentials) {
+    for (const cred of options.publicKey.excludeCredentials) {
+      cred.id = decodeURLEncodedBase64(cred.id);
+    }
+  }
+
+  try {
+    const credential = await navigator.credentials.create({
+      publicKey: options.publicKey,
+    });
+    await webauthnRegistered(credential);
+  } catch (err) {
+    webAuthnError('unknown', err);
+  }
+}