Validate GitHub token in authentication

lib50/_errors.py

@@ -11,7 +11,8 @@
     "MissingToolError",
     "TimeoutError",
     "ConnectionError",
-    "RejectedHonestyPromptError"
+    "RejectedHonestyPromptError",
+    "InvalidTokenError"
 ]
 
 
@@ -110,4 +111,9 @@ class InvalidSignatureError(Error):
 
 class RejectedHonestyPromptError(Error):
     """A ``lib50.Error`` signalling the honesty prompt was rejected by the user."""
+    pass
+
+
+class InvalidTokenError(Error):
+    """A ``lib50.Error`` signalling that the GitHub token is invalid or expired."""
     pass

lib50/authentication.py

@@ -4,6 +4,7 @@
 import os
 import pexpect
 import re
+import requests
 import sys
 import termcolor
 import termios
@@ -13,7 +14,7 @@
 
 from . import _
 from . import _api as api
-from ._errors import ConnectionError, InvalidBranchError, RejectedHonestyPromptError
+from ._errors import ConnectionError, InvalidBranchError, InvalidTokenError, RejectedHonestyPromptError
 
 __all__ = ["User", "authenticate", "logout"]
 
@@ -249,6 +250,16 @@ def _authenticate_https(org, repo=None):
             print(termcolor.colored(prompt, color="yellow", attrs=["bold"]))
             logout()
             sys.exit(1)
+
+        # Validate that the token is actually working
+        try:
+            _validate_github_token(password)
+        except InvalidTokenError:
+            msg = _("There seems to be an issue authenticating with your GitHub token."\
+                " Please visit https://cs50.dev/restart to restart your codespace and try again.")
+            print(termcolor.colored(msg, color="yellow", attrs=["bold"]))
+            logout()
+            sys.exit(1)
 
     # Otherwise, get credentials from cache if possible
     if username is None or password is None:
@@ -331,6 +342,30 @@ def _show_gh_changes_warning():
     _show_gh_changes_warning.showed = True
 
 
+def _validate_github_token(token):
+    """Validate a GitHub token by making an authenticated request to the GitHub API."""
+    try:
+        response = requests.get(
+            "https://api.github.com/user",
+            headers={
+                "Accept": "application/vnd.github+json",
+                "Authorization": f"Bearer {token}",
+                "X-GitHub-Api-Version": "2022-11-28"
+            },
+            timeout=10
+        )
+
+        if response.status_code in (401, 403):
+            raise InvalidTokenError()
+        elif not response.ok:
+            raise ConnectionError(f"Could not validate GitHub token. Received status code: {response.status_code}")
+
+    except requests.exceptions.Timeout:
+        raise ConnectionError("Connection to GitHub timed out while validating token.")
+    except requests.exceptions.RequestException as e:
+        raise ConnectionError(f"Could not connect to GitHub to validate token: {e}")
+
+
 def _prompt_username(prompt="Username: "):
     """Prompt the user for username."""
     try:

setup.py

@@ -27,6 +27,6 @@
     python_requires=">= 3.10",
     packages=["lib50"],
     url="https://github.com/cs50/lib50",
-    version="3.2.0",
+    version="3.2.1",
     include_package_data=True
 )