Draft OpenID Connect support.

frontend/auth/restricted/RestrictedApi.vue

@@ -2,6 +2,7 @@
   <RestrictedAuth
     :mode="authMode"
     :remote-auth-token="remoteAuthToken"
+    :oidc-query-string="oidcQueryString"
     @authenticated="handleAuthenticated"
     @back="handleBack"
   />
@@ -15,6 +16,9 @@ import RestrictedAuth from '@/components/RestrictedAuth.vue'
 // The token is a 5-word passphrase like "word1.word2.word3.word4.word5"
 const remoteAuthToken = ref(null)
 
+// For OIDC flow, pass the raw query string to preserve exact param values
+const oidcQueryString = window.location.search.includes('client_id=') ? window.location.search : null
+
 function extractRemoteToken() {
   const path = window.location.pathname
   // Match /auth/{token} where token is a passphrase with dots
@@ -41,6 +45,11 @@ function postToParent(message) {
 }
 
 function handleAuthenticated(result) {
+  if (result.redirect_url) {
+    // OIDC flow: redirect to client with auth code
+    window.location.href = result.redirect_url
+    return
+  }
   postToParent({
     type: 'auth-success',
     authenticated: true,

frontend/src/components/RestrictedAuth.vue

@@ -67,6 +67,10 @@ const props = defineProps({
     type: String,
     default: 'login',
     validator: (value) => ['login', 'reauth', 'forbidden'].includes(value)
+  },
+  oidcQueryString: {
+    type: String,
+    default: null
   }
 })
 
@@ -163,7 +167,7 @@ async function authenticateUser() {
   loading.value = true
   showMessage('Starting authentication…', 'info')
   let result
-  try { result = await passkey.authenticate() } catch (error) {
+  try { result = await passkey.authenticate(props.oidcQueryString) } catch (error) {
     loading.value = false
     const message = error?.message || 'Passkey authentication cancelled'
     const cancelled = message === 'Passkey authentication cancelled'
@@ -171,6 +175,12 @@ async function authenticateUser() {
     emit('auth-error', { message, cancelled })
     return
   }
+  // OIDC flow: no session cookie, just emit the redirect_url
+  if (result.redirect_url) {
+    loading.value = false
+    emit('authenticated', result)
+    return
+  }
   try { await setSessionCookie(result) } catch (error) {
     loading.value = false
     const message = error?.message || 'Failed to establish session'

frontend/src/utils/passkey.js

@@ -54,8 +54,13 @@ export async function register(resetToken = null, displayName = null, onstartreg
   }
 }
 
-export async function authenticate() {
-  const ws = await aWebSocket(await makeUrl('/auth/ws/authenticate'))
+export async function authenticate(queryString = null) {
+  // Build URL, optionally appending raw query string (e.g. for OIDC params)
+  let url = await makeUrl('/auth/ws/authenticate')
+  if (queryString) {
+    url += queryString.startsWith('?') ? queryString : `?${queryString}`
+  }
+  const ws = await aWebSocket(url)
   try {
     let res = await ws.receive_json()
     if (res.status >= 400) throw new Error(res.detail || `Authentication failed: ${res.status}`)