diff --git a/PFERD/crawl/ilias/ilias_web_crawler.py b/PFERD/crawl/ilias/ilias_web_crawler.py
index ba7d564..166034f 100644
--- a/PFERD/crawl/ilias/ilias_web_crawler.py
+++ b/PFERD/crawl/ilias/ilias_web_crawler.py
@@ -24,10 +24,34 @@ from .kit_ilias_html import (IliasElementType, IliasForumThread, IliasLearningMo
                              IliasPageElement, _sanitize_path_name, parse_ilias_forum_export)
 
 TargetType = Union[str, int]
-_ILIAS_URL = "https://ilias.studium.kit.edu"
+
+
+class IliasConfig():
+    def __init__(self, base_url: str, client_id: str):
+        self._base_url = base_url
+        self._client_id = client_id
+
+    @property
+    def base_url(self) -> str:
+        return self._base_url
+
+    @property
+    def client_id(self) -> str:
+        return self._client_id
 
 
 class IliasWebCrawlerSection(HttpCrawlerSection):
+    def conf(self) -> IliasConfig:
+        base_url = self.s.get("base_url")
+        if not base_url:
+            self.missing_value("base_url")
+
+        client_id = self.s.get("client_id")
+        if not client_id:
+            self.missing_value("client_id")
+
+        return IliasConfig(base_url, client_id)
+
     def target(self) -> TargetType:
         target = self.s.get("target")
         if not target:
@@ -39,7 +63,7 @@ class IliasWebCrawlerSection(HttpCrawlerSection):
         if target == "desktop":
             # Full personal desktop
             return target
-        if target.startswith(_ILIAS_URL):
+        if target.startswith(self.conf().base_url):
             # ILIAS URL
             return target
 
@@ -140,7 +164,7 @@ instance's greatest bottleneck.
             """.strip())
 
         self._auth = auth
-        self._base_url = _ILIAS_URL
+        self._conf = section.conf()
 
         self._target = section.target()
         self._link_file_redirect_delay = section.link_redirect_delay()
@@ -163,7 +187,7 @@ instance's greatest bottleneck.
     async def _crawl_course(self, course_id: int) -> None:
         # Start crawling at the given course
         root_url = url_set_query_param(
-            self._base_url + "/goto.php", "target", f"crs_{course_id}"
+            self._conf.base_url + "/goto.php", "target", f"crs_{course_id}"
         )
 
         await self._crawl_url(root_url, expected_id=course_id)
@@ -171,7 +195,7 @@ instance's greatest bottleneck.
     async def _crawl_desktop(self) -> None:
         appendix = r"ILIAS\Repository\Provider\RepositoryMainBarProvider|mm_pd_sel_items"
         appendix = appendix.encode("ASCII").hex()
-        await self._crawl_url(self._base_url + "/gs_content.php?item=" + appendix)
+        await self._crawl_url(self._conf.base_url + "/gs_content.php?item=" + appendix)
 
     async def _crawl_url(self, url: str, expected_id: Optional[int] = None) -> None:
         maybe_cl = await self.crawl(PurePath("."))
@@ -844,8 +868,8 @@ instance's greatest bottleneck.
                 continue
             if elem.name == "img":
                 if src := elem.attrs.get("src", None):
-                    url = urljoin(_ILIAS_URL, src)
-                    if not url.startswith(_ILIAS_URL):
+                    url = urljoin(self._conf.base_url, src)
+                    if not url.startswith(self._conf.base_url):
                         continue
                     log.explain(f"Internalizing {url!r}")
                     img = await self._get_authenticated(url)
@@ -925,7 +949,63 @@ instance's greatest bottleneck.
                 return await request.read()
         raise CrawlError("get_authenticated failed even after authenticating")
 
-    # ToDo: Is this still required?
+    # ToDo: Is iorepeat still required?
     @_iorepeat(3, "Login", failure_is_error=True)
     async def _authenticate(self) -> None:
-        pass
+        # fill the session with the correct cookies
+        params = {
+            "client_id": self._conf.client_id,
+            "cmd": "force_login",
+        }
+        async with self.session.get(f"{self._conf.base_url}/login.php", params=params) as request:
+            login_page = soupify(await request.read())
+
+        login_form = login_page.find("form", attrs={"name": "formlogin"})
+        if login_form is None:
+            raise CrawlError("Could not find the login form! Specified client id might be invalid.")
+
+        login_url = login_form.attrs.get("action")
+        if login_url is None:
+            raise CrawlError("Could not find the action URL in the login form!")
+
+        username, password = await self._auth.credentials()
+
+        login_data = {
+            "username": username,
+            "password": password,
+            "cmd[doStandardAuthentication]": "Login",
+        }
+
+        # do the actual login
+        async with self.session.post(f"{self._conf.base_url}/{login_url}", data=login_data) as request:
+            soup = soupify(await request.read())
+            if not self._is_logged_in(soup):
+                self._auth.invalidate_credentials()
+
+    @ staticmethod
+    def _is_logged_in(soup: BeautifulSoup) -> bool:
+        # Normal ILIAS pages
+        mainbar: Optional[Tag] = soup.find(class_="il-maincontrols-metabar")
+        if mainbar is not None:
+            login_button = mainbar.find(attrs={"href": lambda x: x and "login.php" in x})
+            shib_login = soup.find(id="button_shib_login")
+            return not login_button and not shib_login
+
+        # Personal Desktop
+        if soup.find("a", attrs={"href": lambda x: x and "block_type=pditems" in x}):
+            return True
+
+        # Video listing embeds do not have complete ILIAS html. Try to match them by
+        # their video listing table
+        video_table = soup.find(
+            recursive=True,
+            name="table",
+            attrs={"id": lambda x: x is not None and x.startswith("tbl_xoct")}
+        )
+        if video_table is not None:
+            return True
+        # The individual video player wrapper page has nothing of the above.
+        # Match it by its playerContainer.
+        if soup.select_one("#playerContainer") is not None:
+            return True
+        return False