Merge branch 'release-0.4'

CHANGELOG

@@ -1,4 +1,8 @@
-Release xxx:
+Release 0.4:
+• Security: Refuse to run if wayland session is detected. Running in a wayland
+  is insecure.
+
+Release 0.3:
 • Enhancement: Make pyxtrlock conform to the XDG specification. Patch by
   Cristian Ciupitu.
 • Enhancement: Ship script to create an empty lock symbol. Patch by Alexander

README.md

@@ -90,11 +90,14 @@ mailing list.
 
 Bugs & Limitations
 ------------------
-Additional input devices other than the keyboard and mouse are not disabled.
+Pyxtrlock can only securely lock X11 sessions. Running pyxtrlock in other
+session types, such as Wayland, is insecure and not supported. Pyxtrlock tries
+to detect Wayland sessions and abort with an error message.
+
+Pyxtrlock does not prevent a user from switching to a virtual
+terminal, so be advised to always log out from your terminals.
 
-Although this is not a bug, please note that pyxtrlock does not
-prevent a user from switching to a virtual terminal, so be advised to
-always log out from your terminals.
+Additional input devices other than the keyboard and mouse are not disabled.
 
 The length of the password is limited to 100 KiB to prevent memory
 exhaustion attacks. This limit can only be adapted in the source code.

bin/pyxtrlock

@@ -13,6 +13,7 @@ import simplepam as pam
 
 from pyxtrlock.cursor_file import load_cursor
 from pyxtrlock import panic
+from pyxtrlock import require_x11_session
 try:
     import pyxtrlock.xcb as xcb
 except ImportError as err:
@@ -23,6 +24,8 @@ try:
 except ImportError as err:
     panic(err)
 
+require_x11_session()
+
 if getpass.getuser() == 'root' and sys.argv[1:] != ['-f']:
     msg = (
         "refusing to run as root. Use -f to force. Warning: "

pyxtrlock/__init__.py

@@ -1,8 +1,48 @@
 
+import os
+import socket
 import sys
 
+from xdg.BaseDirectory import get_runtime_dir
+
 
 def panic(*message_parts, exit_code=1):
     """Print an error message to stderr and exit"""
     print("pyxtrlock:", *message_parts, file=sys.stderr)
     sys.exit(exit_code)
+
+
+def require_x11_session():
+    """
+    Detect whether we're running in a Wayland session and abort if so.
+    """
+
+    if os.environ.get("XDG_SESSION_TYPE") == "x11":
+        return
+
+    if os.environ.get("WAYLAND_DISPLAY"):
+        panic(
+            "WAYLAND_DISPLAY is set, suspecting Wayland session. "
+            "Using pyxtrlock in a Wayland session is insecure. Aborting."
+        )
+
+    if os.environ.get("WAYLAND_SOCKET"):
+        panic(
+            "WAYLAND_SOCKET is set, suspecting Wayland session. "
+            "Using pyxtrlock in a Wayland session is insecure. Aborting."
+        )
+
+    xdg_runtime_dir = get_runtime_dir(strict=True)
+    wayland_socket = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM, 0)
+
+    try:
+        wayland_socket.connect(os.path.join(xdg_runtime_dir, "wayland-0"))
+    except OSError:
+        return
+    else:
+        panic(
+            "Successfully connected to Wayland socket, suspecting Wayland session. "
+            "Using pyxtrlock in a Wayland session is insecure. Aborting."
+        )
+    finally:
+        wayland_socket.close()

setup.py

@@ -33,14 +33,14 @@
 ]
 
 setup(name='pyxtrlock',
-      version='0.3',
+      version='0.4',
       author=authors,
       author_email='[email protected]',
       requires=['simplepam', 'pyxdg'],
       packages=['pyxtrlock'],
       scripts=['bin/pyxtrlock'],
       license='GPLv3+',
-      url='https://zombofant.net/hacking/pyxtrlock',
+      url='https://github.com/leonnnn/pyxtrlock',
       description=desc,
       long_description=long_desc,
       classifiers=classifiers