Achievement_Inputing/accounts/static/accounts/login.js

function getCookie(name) {
  const value = `; ${document.cookie}`;
  const parts = value.split(`; ${name}=`);
  if (parts.length === 2) return parts.pop().split(';').shift();
}

function base64ToArrayBuffer(b64) {
  const binary = atob(b64);
  const bytes = new Uint8Array(binary.length);
  for (let i = 0; i < binary.length; i++) bytes[i] = binary.charCodeAt(i);
  return bytes.buffer;
}

function arrayBufferToBase64(buffer) {
  const bytes = new Uint8Array(buffer);
  let binary = '';
  for (let i = 0; i < bytes.byteLength; i++) binary += String.fromCharCode(bytes[i]);
  return btoa(binary);
}

async function importRsaPublicKey(spkiBytes) {
  return window.crypto.subtle.importKey('spki', spkiBytes, { name: 'RSA-OAEP', hash: 'SHA-256' }, false, ['encrypt']);
}

async function rsaOaepEncrypt(publicKey, dataBytes) {
  const encrypted = await window.crypto.subtle.encrypt({ name: 'RSA-OAEP' }, publicKey, dataBytes);
  return new Uint8Array(encrypted);
}

async function importAesKey(keyBytes) {
  return window.crypto.subtle.importKey('raw', keyBytes, { name: 'AES-GCM' }, false, ['encrypt']);
}

async function aesGcmEncrypt(aesKey, ivBytes, dataBytes) {
  const ct = await window.crypto.subtle.encrypt({ name: 'AES-GCM', iv: ivBytes }, aesKey, dataBytes);
  return new Uint8Array(ct);
}

let needCaptcha = false;

async function loadCaptcha() {
  const csrftoken = getCookie('csrftoken');
  const resp = await fetch('/accounts/captcha/', { method: 'GET', credentials: 'same-origin', headers: { 'X-CSRFToken': csrftoken || '' } });
  const data = await resp.json();
  if (resp.ok && data.ok) {
    const img = document.getElementById('captchaImg');
    const box = document.getElementById('captchaBox');
    img.src = 'data:image/png;base64,' + data.image_b64;
    box.style.display = 'block';
  }
}

document.getElementById('loginForm').addEventListener('submit', async (e) => {
  e.preventDefault();
  const errorEl = document.getElementById('error');
  errorEl.textContent = '';

  const username = document.getElementById('username').value.trim();
  const password = document.getElementById('password').value;
  if (!username || !password) { errorEl.textContent = '请输入账户与密码'; return; }

  const btn = document.getElementById('loginBtn');
  btn.disabled = true;

  try {
    const csrftoken = getCookie('csrftoken');
    const pkResp = await fetch('/accounts/pubkey/', { method: 'GET', credentials: 'same-origin', headers: { 'X-CSRFToken': csrftoken || '' } });
    if (!pkResp.ok) throw new Error('获取公钥失败');
    const pkJson = await pkResp.json();
    const spkiBytes = new Uint8Array(base64ToArrayBuffer(pkJson.public_key_spki));
    const pubKey = await importRsaPublicKey(spkiBytes);

    const aesKeyRaw = new Uint8Array(32); window.crypto.getRandomValues(aesKeyRaw);
    const encAesKey = await rsaOaepEncrypt(pubKey, aesKeyRaw);
    const encAesKeyB64 = arrayBufferToBase64(encAesKey);

    const setKeyResp = await fetch('/accounts/session-key/', {
      method: 'POST', credentials: 'same-origin', headers: { 'Content-Type': 'application/json', 'X-CSRFToken': csrftoken || '' }, body: JSON.stringify({ encrypted_key: encAesKeyB64 })
    });
    const setKeySnapshot = await (async () => {
      const clone = setKeyResp.clone();
      const txt = await clone.text();
      let parsed = null;
      try { parsed = await setKeyResp.json(); } catch (_) {}
      return { txt, parsed };
    })();
    if (!setKeySnapshot.parsed) {
      const msg = (setKeySnapshot.txt || '').trim();
      const mapped = msg.toLowerCase().includes('decrypt error') ? '会话密钥解密失败，请刷新页面后重试' : (msg || '设置会话密钥失败');
      throw new Error(mapped);
    }
    const setKeyJson = setKeySnapshot.parsed;
    if (!setKeyResp.ok || !setKeyJson.ok) throw new Error(setKeyJson.message || '设置会话密钥失败');

    const aesKey = await importAesKey(aesKeyRaw);
    const iv = new Uint8Array(12); window.crypto.getRandomValues(iv);
    const obj = { username, password };
    if (needCaptcha) obj.captcha = (document.getElementById('captcha').value || '').trim();
    const payload = new TextEncoder().encode(JSON.stringify(obj));
    const ct = await aesGcmEncrypt(aesKey, iv, payload);
    const ctB64 = arrayBufferToBase64(ct);
    const ivB64 = arrayBufferToBase64(iv);

    const submitResp = await fetch('/accounts/login/secure-submit/', {
      method: 'POST', credentials: 'same-origin', headers: { 'Content-Type': 'application/json', 'X-CSRFToken': csrftoken || '' }, body: JSON.stringify({ iv: ivB64, ciphertext: ctB64 })
    });
    const submitSnapshot = await (async () => {
      const clone = submitResp.clone();
      const txt = await clone.text();
      let parsed = null;
      try { parsed = await submitResp.json(); } catch (_) {}
      return { txt, parsed };
    })();
    if (!submitSnapshot.parsed) {
      const msg = (submitSnapshot.txt || '').trim();
      const mapped = msg.toLowerCase().includes('decrypt error') ? '解密失败，请刷新页面后重试' : (msg || '服务器响应异常');
      throw new Error(mapped);
    }
    const submitJson = submitSnapshot.parsed;
    if (!submitResp.ok || !submitJson.ok) {
      if (submitJson && submitJson.captcha_required) { needCaptcha = true; await loadCaptcha(); }
      throw new Error(submitJson.message || '登录失败');
    }
    window.location.href = submitJson.redirect_url;
  } catch (err) {
    console.error(err);
    errorEl.textContent = err.message || '发生错误';
  } finally {
    btn.disabled = false;
  }
});

document.getElementById('refreshCaptcha').addEventListener('click', async () => {
  needCaptcha = true;
  await loadCaptcha();
});