Härtung und Sammelpostfach per SSO (#1)

tests/test_oauth.py

@@ -0,0 +1,141 @@
+"""Tests for the OAuth connection of the collection mailbox."""
+
+import base64
+import json
+from urllib.parse import parse_qs, urlparse
+
+import httpx
+import pytest
+from cryptography.fernet import Fernet
+
+import oauth
+
+
+def _jwt(claims):
+    enc = lambda d: base64.urlsafe_b64encode(json.dumps(d).encode()).rstrip(b"=").decode()  # noqa: E731
+    return f"{enc({'alg': 'RS256'})}.{enc(claims)}.sig"
+
+
+class Clock:
+    now = 1000.0
+
+    def __call__(self):
+        return self.now
+
+
+def _mb(tmp_path, responses, seen=None, clock=None):
+    def handler(request):
+        if seen is not None:
+            seen.append(parse_qs(request.content.decode()))
+        return responses.pop(0)
+    return oauth.MailboxOAuth(
+        "https://sso.example.org", "unsubscriber", "secret", "https://u.example.org/oidc/callback",
+        "unsubscribe-bot@example.org", tmp_path, Fernet.generate_key().decode(),
+        transport=httpx.MockTransport(handler), clock=clock or Clock(),
+    )
+
+
+def _start_state(mb):
+    url = urlparse(mb.start())
+    q = parse_qs(url.query)
+    assert q["prompt"] == ["login"] and q["login_hint"] == ["unsubscribe-bot@example.org"]
+    assert "offline_access" in q["scope"][0] and q["code_challenge_method"] == ["S256"]
+    return q["state"][0]
+
+
+def test_connect_stores_encrypted_refresh_token(tmp_path):
+    mb = _mb(tmp_path, [httpx.Response(200, json={
+        "access_token": _jwt({"email": "Unsubscribe-Bot@example.org"}), "refresh_token": "rt-1", "expires_in": 3600})])
+    mb.finish(_start_state(mb), "code")
+    assert mb.connected()
+    assert b"rt-1" not in (tmp_path / "oauth-token").read_bytes()
+    assert oct((tmp_path / "oauth-token").stat().st_mode)[-3:] == "600"
+
+
+def test_connect_with_wrong_account_is_rejected(tmp_path):
+    mb = _mb(tmp_path, [httpx.Response(200, json={
+        "access_token": _jwt({"email": "philipp@example.org"}), "refresh_token": "rt", "expires_in": 3600})])
+    with pytest.raises(oauth.OAuthError, match="expected unsubscribe-bot"):
+        mb.finish(_start_state(mb), "code")
+    assert not mb.connected()
+
+
+def test_unknown_state_is_rejected(tmp_path):
+    with pytest.raises(oauth.OAuthError):
+        _mb(tmp_path, []).finish("forged", "code")
+
+
+def test_access_token_refreshes_and_rotates(tmp_path):
+    seen, clock = [], Clock()
+    mb = _mb(tmp_path, [
+        httpx.Response(200, json={"access_token": _jwt({"email": "unsubscribe-bot@example.org"}),
+                                  "refresh_token": "rt-1", "expires_in": 3600}),
+        httpx.Response(200, json={"access_token": "at-2", "refresh_token": "rt-2", "expires_in": 3600}),
+    ], seen, clock)
+    mb.finish(_start_state(mb), "code")
+    first = mb.access_token()
+    assert len(seen) == 1                       # cached from the code exchange
+    clock.now += 3600
+    assert mb.access_token() == "at-2" != first
+    assert seen[1]["refresh_token"] == ["rt-1"]
+    assert mb._read_refresh() == "rt-2"
+
+
+def test_revoked_token_disconnects(tmp_path):
+    clock = Clock()
+    mb = _mb(tmp_path, [
+        httpx.Response(200, json={"access_token": _jwt({"email": "unsubscribe-bot@example.org"}),
+                                  "refresh_token": "rt-1", "expires_in": 10}),
+        httpx.Response(400, json={"error": "invalid_grant"}),
+    ], clock=clock)
+    mb.finish(_start_state(mb), "code")
+    clock.now += 100
+    with pytest.raises(oauth.OAuthError):
+        mb.access_token()
+    assert not mb.connected()
+
+
+def test_not_connected(tmp_path):
+    with pytest.raises(oauth.OAuthError):
+        _mb(tmp_path, []).access_token()
+
+
+def test_app_uses_xoauth2_when_oauth_configured(monkeypatch):
+    import app as unsub
+
+    calls = {}
+
+    class FakeIMAP:
+        def __init__(self, host, port):
+            pass
+
+        def authenticate(self, mech, cb):
+            calls["auth"] = (mech, cb(b""))
+
+        def login(self, *a):
+            calls["login"] = a
+
+        def select(self, folder):
+            pass
+
+    class FakeOAuth:
+        def access_token(self):
+            return "tok"
+
+    monkeypatch.setattr(unsub.imaplib, "IMAP4_SSL", FakeIMAP)
+    monkeypatch.setattr(unsub, "OAUTH", FakeOAuth())
+    monkeypatch.setattr(unsub, "EMAIL_USERNAME", "unsubscribe-bot@example.org")
+    unsub.connect()
+    assert calls == {"auth": ("XOAUTH2", oauth.xoauth2_string("unsubscribe-bot@example.org", "tok").encode())}
+
+
+def test_index_shows_connect_when_not_connected(monkeypatch):
+    import app as unsub
+
+    class FakeOAuth:
+        def connected(self):
+            return False
+
+    monkeypatch.setattr(unsub, "OAUTH", FakeOAuth())
+    html = unsub.app.test_client().get("/").get_data(as_text=True)
+    assert 'action="/connect"' in html and 'action="/result"' not in html