Merge pull request #24 from pezkuwichain/fix/function-authorization

fix(security): identify the caller from their token, not the request body

web/supabase/functions/_shared/caller-auth.ts

@@ -0,0 +1,81 @@
+// Identify the caller from their JWT instead of trusting the request body.
+//
+// Functions that run with the service role bypass RLS entirely, so whatever
+// user id they act on is the whole authorisation decision. Reading that id from
+// the body means any caller can name any account: with only the public anon key
+// — which every browser has — a request could read or change another user's
+// records. VERIFY_JWT does not help, because the anon key is itself a valid JWT.
+//
+// The client already sends the signed-in user's token: supabase.functions.invoke
+// puts the session access token in the Authorization header. These helpers read
+// the caller from it, so the body's userId can be ignored.
+
+import type { SupabaseClient } from 'https://esm.sh/@supabase/supabase-js@2.39.3'
+
+export const ALLOWED_ORIGINS = [
+  'https://app.pezkuwichain.io',
+  'https://www.pezkuwichain.io',
+  'https://pezkuwichain.io',
+  'https://pex.mom',
+]
+
+export function getCorsHeaders(origin: string | null): Record<string, string> {
+  const allowedOrigin = origin && ALLOWED_ORIGINS.includes(origin) ? origin : ALLOWED_ORIGINS[0]
+  return {
+    'Access-Control-Allow-Origin': allowedOrigin,
+    'Access-Control-Allow-Headers': 'authorization, x-client-info, apikey, content-type',
+    'Access-Control-Allow-Methods': 'POST, OPTIONS',
+    'Access-Control-Allow-Credentials': 'true',
+  }
+}
+
+/**
+ * The signed-in user behind this request, or null.
+ *
+ * Returns null for the anon key: it carries no user, so getUser rejects it.
+ * That is the point — an anon-key call must not be able to act on an account.
+ */
+export async function getCaller(
+  req: Request,
+  serviceClient: SupabaseClient
+): Promise<{ id: string; email?: string } | null> {
+  const header = req.headers.get('Authorization')
+  if (!header?.startsWith('Bearer ')) return null
+
+  const jwt = header.slice('Bearer '.length).trim()
+  if (!jwt) return null
+
+  const {
+    data: { user },
+    error,
+  } = await serviceClient.auth.getUser(jwt)
+
+  if (error || !user) return null
+  return { id: user.id, email: user.email ?? undefined }
+}
+
+/** Admin or super_admin in admin_roles. Moderators are not admins here. */
+export async function isAdmin(serviceClient: SupabaseClient, userId: string): Promise<boolean> {
+  const { data, error } = await serviceClient
+    .from('admin_roles')
+    .select('role')
+    .eq('user_id', userId)
+    .maybeSingle()
+
+  if (error || !data) return false
+  return data.role === 'super_admin' || data.role === 'admin'
+}
+
+export function unauthorized(corsHeaders: Record<string, string>, message = 'Unauthorized') {
+  return new Response(JSON.stringify({ error: message }), {
+    status: 401,
+    headers: { ...corsHeaders, 'Content-Type': 'application/json' },
+  })
+}
+
+export function forbidden(corsHeaders: Record<string, string>, message = 'Forbidden') {
+  return new Response(JSON.stringify({ error: message }), {
+    status: 403,
+    headers: { ...corsHeaders, 'Content-Type': 'application/json' },
+  })
+}

web/supabase/functions/notifications-manager/index.ts

@@ -1,10 +1,14 @@
-export const corsHeaders = {
-  "Access-Control-Allow-Origin": "*",
-  "Access-Control-Allow-Headers":
-    "authorization, x-client-info, apikey, content-type",
-};
+import {
+  forbidden,
+  getCaller,
+  getCorsHeaders,
+  isAdmin,
+  unauthorized,
+} from "../_shared/caller-auth.ts";
 
 Deno.serve(async (req) => {
+  const corsHeaders = getCorsHeaders(req.headers.get("origin"));
+
   if (req.method === "OPTIONS") {
     return new Response("ok", { headers: corsHeaders });
   }
@@ -12,7 +16,7 @@ Deno.serve(async (req) => {
   try {
     const {
       action,
-      userId,
+      userId: requestedUserId,
       notificationId,
       title,
       message,
@@ -28,6 +32,22 @@ Deno.serve(async (req) => {
     const supabaseServiceKey = Deno.env.get("SUPABASE_SERVICE_ROLE_KEY")!;
     const supabase = createClient(supabaseUrl, supabaseServiceKey);
 
+    // Read the account from the caller's token, not the body. Reading it from
+    // the body let an anon-key request list, delete or forge anyone's
+    // notifications.
+    const caller = await getCaller(req, supabase);
+    if (!caller) return unauthorized(corsHeaders);
+
+    // AdminPanel legitimately notifies other users, so create is the one action
+    // allowed to target someone else - and only for an admin.
+    let userId = caller.id;
+    if (action === "create" && requestedUserId && requestedUserId !== caller.id) {
+      if (!(await isAdmin(supabase, caller.id))) {
+        return forbidden(corsHeaders, "Only admins can notify other users");
+      }
+      userId = requestedUserId;
+    }
+
     let result;
 
     switch (action) {

web/supabase/functions/two-factor-auth/index.ts

@@ -1,10 +1,5 @@
 import { createClient } from "https://esm.sh/@supabase/supabase-js@2.39.3";
-
-export const corsHeaders = {
-  "Access-Control-Allow-Origin": "*",
-  "Access-Control-Allow-Headers":
-    "authorization, x-client-info, apikey, content-type",
-};
+import { getCaller, getCorsHeaders, unauthorized } from "../_shared/caller-auth.ts";
 
 function generateSecret(): string {
   const chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZ234567";
@@ -45,6 +40,8 @@ function generateTOTP(secret: string, window: number = 0): string {
 }
 
 Deno.serve(async (req) => {
+  const corsHeaders = getCorsHeaders(req.headers.get("origin"));
+
   if (req.method === "OPTIONS") {
     return new Response("ok", { headers: corsHeaders });
   }
@@ -54,7 +51,14 @@ Deno.serve(async (req) => {
     const supabaseServiceKey = Deno.env.get("SUPABASE_SERVICE_ROLE_KEY")!;
     const supabase = createClient(supabaseUrl, supabaseServiceKey);
 
-    const { action, userId, code, backupCode } = await req.json();
+    // Every action below touches one account's 2FA state, so the account is
+    // taken from the caller's token. The body used to name it, which let an
+    // anon-key request read or disable anyone's 2FA.
+    const caller = await getCaller(req, supabase);
+    if (!caller) return unauthorized(corsHeaders);
+    const userId = caller.id;
+
+    const { action, code, backupCode } = await req.json();
 
     switch (action) {
       case "setup": {