Feat: Endpoint to provide user's scrypt params

functions/api/auth-params.js

@@ -0,0 +1,15 @@
+const json = (d, o) => new Response(JSON.stringify(d), { ...o, headers: { 'Content-Type': 'application/json', ...(o?.headers || {}) } });
+
+export async function onRequest({ request, env }) {
+  const u = new URL(request.url).searchParams.get('username');
+  if (!u) return json({ error: 'Username required' }, { status: 400 });
+  try {
+    const user = await env.D1_SPCHCAP.prepare('SELECT pass_hash FROM users WHERE username=?').bind(u).first();
+    if (!user) return json({ error: 'User not found' }, { status: 404 });
+    const [f, N, r, p, s] = user.pass_hash.split('$');
+    if (f!=='scrypt') return json({ error: 'Invalid hash format' }, { status: 500 });
+    return json({ N:parseInt(N), r:parseInt(r), p:parseInt(p), salt_b64:s });
+  } catch (e) {
+    return json({ error: { message: e.message } }, { status: 500 });
+  }
+}