Merge pull request #157 from ustclug/zju_auth

Add authentication provider for zju

.github/workflows/smoketest.yml

@@ -28,7 +28,7 @@ jobs:
         python3 -m venv .venv
         source .venv/bin/activate
         pip install --upgrade pip
-        pip install -r requirements.txt
+        pip install -r requirements-lock.txt
 
         cp conf/local_settings.py.example conf/local_settings.py
         PRIVATE_KEY=$(openssl ecparam -name secp256k1 -genkey -noout)

frontend/auth_providers/zju.py

@@ -1,24 +1,106 @@
-from datetime import timedelta
+import secrets
+import string
+import json
+from typing import Any
+from Crypto.Cipher import AES
+from base64 import b64decode
+from urllib.parse import urlencode
 
+from django.conf import settings
+from django.contrib import messages
+from django.shortcuts import redirect
+from django.template.response import TemplateResponse
 from django.urls import path
+from django.utils.decorators import method_decorator
+from django.views.decorators.csrf import csrf_exempt
 
-from .base import DomainEmailValidator
-from .external import ExternalLoginView, ExternalGetCodeView
+from .base import BaseLoginView
 
 
-class LoginView(ExternalLoginView):
-    template_context = {'provider_name': '浙江大学'}
-    provider = 'zju'
-    group = 'zju'
+class LoginView(BaseLoginView):
+    template_name = "login_info.html"
+    template_context = {
+        "provider_name": "浙江大学统一身份认证",
+        "info": "此次登录需要您处在一个能够访问浙江大学内网的环境；如果您不在校内，请尝试使用 RVPN 等工具访问内网；确认能访问内网后，请单击登录按钮。",
+    }
+    provider = "zju"
+    group = "zju"
 
+    def __init__(self, **kwargs: Any) -> None:
+        super().__init__(**kwargs)
+        # 避免 local_settings 未配置时出错
+        provider = settings.EXTERNAL_LOGINS.get(self.provider)
+        if not provider:
+            raise RuntimeError(f"未配置{self.template_context['provider_name']}登录")
+        self.state_key = provider["state_key"].encode()
+        self.cipher_key = b64decode(provider["cipher_key"])
+        self.provider_url = provider["provider_url"]
 
-class GetCodeView(ExternalGetCodeView):
-    provider = 'zju'
-    duration = timedelta(hours=1)
-    validate_identity = DomainEmailValidator('zju.edu.cn')
+    # XXX: POST 请求到外部，不宜外传 csrf token，且反 CSRF 的功能已被 nonce 实现
+    @method_decorator(csrf_exempt)
+    def dispatch(self, *args, **kwargs):
+        return super(LoginView, self).dispatch(*args, **kwargs)
+
+    def normalize_identity(self):
+        return self.identity.casefold()
+
+    def check_cipher(self) -> bool:
+        try:
+            ciphertext = self.cipher
+            nonce = self.request.session.get("auth_nonce_zju")
+            assert isinstance(ciphertext, str) and isinstance(nonce, str)
+            self.request.session.pop("auth_nonce_zju")
+            # ciphertext:
+            #  16 bytes: nonce
+            #  16 bytes till end - 16 bytes: payload
+            #  16 bytes from end: MAC
+            ciphertext = b64decode(ciphertext)
+            cipher = AES.new(self.cipher_key, AES.MODE_GCM, ciphertext[:16])
+            cipher.update(nonce.encode())
+            payload = json.loads(
+                cipher.decrypt_and_verify(ciphertext[16:-16], ciphertext[-16:])
+            )
+            sno = payload["sno"]
+            assert isinstance(sno, str)
+            sno = sno.strip()
+            # XXX: 实际上的长度是 8，但作为可信内容放宽限制来避免一些特殊情况
+            if not (
+                all(char in string.digits for char in sno)
+                and 5 <= len(sno) <= 26
+            ):
+                messages.error(self.request, "学号非法")
+                return False
+            self.sno = sno
+            self.name = payload["name"]
+            # XXX: 能够以此学号登录应当与拥有此邮箱等价
+            self.identity = sno + "@zju.edu.cn"
+            return True
+        except Exception:
+            messages.error(self.request, "登录失败")
+            return False
+
+    def get(self, request):
+        self.cipher = request.GET.get("cipher")
+        if self.cipher:
+            if self.check_cipher():
+                self.login(email=self.identity, sno=self.sno, name=self.name)
+            return redirect("hub")
+        template_context = self.template_context.copy()
+        nonce = "".join(
+            secrets.choice(string.ascii_letters + string.digits) for _ in range(32)
+        )
+        request.session['auth_nonce_zju'] = nonce
+
+        # 在登录前显示提示信息（而非直接跳转）
+        redirect_uri = request.build_absolute_uri("/accounts/zju/login/")
+        template_context["url"] = (
+            self.provider_url
+            + "?"
+            + urlencode({"redirect_uri": redirect_uri, "nonce": nonce})
+        )
+        return TemplateResponse(request, self.template_name, template_context)
 
 
 urlpatterns = [
-    path('zju/login/', LoginView.as_view()),
-    path('zju/get_code/', GetCodeView.as_view()),
+    path("zju/login/", LoginView.as_view()),
 ]

frontend/templates/login_info.html

@@ -0,0 +1,15 @@
+{% extends 'base.html' %}
+
+{% comment %}包含自定义 info 的登录页模板{% endcomment %}
+
+{% block content %}
+    {% block form %}
+        <h1>{% block heading %}{{ provider_name }}登录{% endblock %}</h1>
+        <button type="submit" onclick="location.href=this.value;" value="{{ url }}" class="pure-button pure-button-primary">登录</button>
+        {% block info %}
+            <div class="msg-info">
+                <p>{{ info }}</p>
+            </div>
+        {% endblock %}
+    {% endblock %}
+{% endblock %}

requirements-lock.txt

@@ -1,22 +1,24 @@
 aliyun-python-sdk-core==2.13.36
 asgiref==3.7.2
 certifi==2023.7.22
-cffi==1.15.1
-charset-normalizer==3.2.0
+cffi==1.16.0
+charset-normalizer==3.3.0
 cryptography==41.0.4
 defusedxml==0.7.1
 Django==4.2.5
 django-allauth==0.57.0
 gevent==23.9.1
-greenlet==3.0.0rc3
+greenlet==3.0.0
 idna==3.4
+importlib-metadata==6.8.0
 jmespath==0.10.0
 Markdown==3.4.4
 oauthlib==3.2.2
 psycopg==3.1.12
 psycopg-binary==3.1.12
 psycopg-pool==3.1.8
 pycparser==2.21
+pycryptodome==3.19.0
 PyJWT==2.8.0
 pymemcache==4.0.0
 pyOpenSSL==23.2.0
@@ -25,8 +27,9 @@ PyYAML==6.0.1
 requests==2.31.0
 requests-oauthlib==1.3.1
 sqlparse==0.4.4
-typing_extensions==4.7.1
+typing-extensions==4.8.0
 urllib3==2.0.6
 uWSGI==2.0.22
+zipp==3.17.0
 zope.event==5.0
-zope.interface==6.0
+zope.interface==6.1

requirements.txt

@@ -8,6 +8,7 @@ Markdown==3.4.4
 psycopg==3.1.12
 psycopg-binary==3.1.12
 psycopg-pool==3.1.8
+pycryptodome==3.19.0
 pymemcache==4.0.0
 pyOpenSSL==23.2.0
 PyYAML==6.0.1