4ev.link/functions/api/signin.js

export async function onRequestPost({ request, env }) {
    try {
        const { 'g-recaptcha-response': token, ...body } = await request.json();
        const vR = await fetch("https://www.google.com/recaptcha/api/siteverify", { method: "POST", headers: { "Content-Type": "application/x-www-form-urlencoded" }, body: `secret=${env.RECAPCHA_KEY}&response=${token}` });
        if (!(await vR.json()).success) return new Response("CAPTCHA verification failed.", { status: 403 });

        const { username, pass_hash } = body;
        if (!username || !pass_hash) return new Response("Missing fields", { status: 400 });

        const user = await env.D1_EV.prepare("SELECT pass_hash FROM users WHERE username = ?").bind(username).first();
        if (user?.pass_hash !== pass_hash) return new Response("Invalid credentials", { status: 401 });
        
        return Response.json({ success: true, username: username });
    } catch (e) {
        return new Response(e.message, { status: 500 });
    }
}