Move verifyFileOnlyWritableByMunkiAndRoot() from munkicommon to managesoftwareupdate, so it can be used without importing munkicommon.py.

This is in prep of a upcoming notification feature that cannot depend on ObjC Py bindings.  Alternatively, if we want to share such code, we can create a common/util module for only Pure-Python code, and doc that it should not contain any ObjC imports.


git-svn-id: http://munki.googlecode.com/svn/trunk@861 a4e17f2e-e282-11dd-95e1-755cbddbdd66

code/client/managedsoftwareupdate

@@ -21,6 +21,7 @@ managedsoftwareupdate
 import sys
 import os
 import optparse
+import stat
 import subprocess
 import time
 import traceback
@@ -35,6 +36,18 @@ from munkilib import appleupdates
 from munkilib import FoundationPlist
 
 
+class Error(Exception):
+    """Class for domain specific exceptions."""
+
+
+class VerifyFilePermissionsError(Error):
+    """There was an error verifying file permissions."""
+
+
+class InsecureFilePermissionsError(VerifyFilePermissionsError):
+    """The permissions of the specified file are insecure."""
+
+
 def getIdleSeconds():
     """Returns the number of seconds since the last mouse or keyboard event."""
     cmd = ['/usr/sbin/ioreg', '-c', 'IOHIDSystem', '-d', '4']
@@ -84,6 +97,43 @@ def clearLastNotifiedDate():
         pass
 
 
+def verifyFileOnlyWritableByMunkiAndRoot(file_path):
+    """
+    Check the permissions on a given file path; fail if owner or group
+    does not match the munki process (default: root/admin) or the group is not
+    'wheel', or if other users are able to write to the file. This prevents
+    escalated execution of arbitrary code.
+
+    Args:
+      file_path: str path of file to verify permissions on.
+    Raises:
+      VerifyFilePermissionsError: there was an error verifying file permissions.
+      InsecureFilePermissionsError: file permissions were found to be insecure.
+    """
+    try:
+        file_stat = os.stat(file_path)
+    except OSError, e:
+        raise VerifyFilePermissionsError(
+            '%s does not exist. \n %s' % (file_path, str(e)))
+
+    try:
+        # verify the munki process uid matches the file owner uid.
+        if os.geteuid() != file_stat.st_uid:
+            raise InsecureFilePermissionsError(
+                'owner does not match munki process!')
+        # verify the munki process gid matches the file owner gid, or the file
+        # owner gid is 80 (which is the admin group root is a member of).
+        elif os.getegid() != file_stat.st_gid and file_stat.st_gid != 80:
+            raise InsecureFilePermissionsError(
+                'group does not match munki process!')
+        # verify other users cannot write to the file.
+        elif file_stat.st_mode & stat.S_IWOTH != 0:
+            raise InsecureFilePermissionsError('world writable!')
+    except InsecureFilePermissionsError, e:
+        raise InsecureFilePermissionsError(
+            '%s is not secure! %s' % (file_path, e.args[0]))
+
+
 def createDirsIfNeeded(dirlist):
     """Create any missing directories needed by the munki tools.
 
@@ -307,7 +357,7 @@ def runPreOrPostFlightScript(script, runtype='custom'):
     """
     if os.path.exists(script):
         try:
-            munkicommon.verifyFileOnlyWritableByMunkiAndRoot(script)
+            verifyFileOnlyWritableByMunkiAndRoot(script)
         except munkicommon.VerifyFilePermissionsError, e:
             msg = ('Skipping execution due to failed file permissions '
                    'verification: %s\n%s' % (script, str(e)))

code/client/munkilib/munkicommon.py

@@ -28,7 +28,6 @@ import hashlib
 import os
 import platform
 import shutil
-import stat
 import struct
 import subprocess
 import sys
@@ -59,14 +58,6 @@ class PreferencesError(Error):
     """There was an error reading the preferences plist."""
 
 
-class VerifyFilePermissionsError(Error):
-    """There was an error verifying file permissions."""
-
-
-class InsecureFilePermissionsError(VerifyFilePermissionsError):
-    """The permissions of the specified file are insecure."""
-
-
 def get_version():
     """Returns version of munkitools, reading version.plist
     and svnversion"""
@@ -1223,8 +1214,8 @@ def getPackageMetaData(pkgitem):
     cataloginfo['receipts'] = receiptinfo
 
     return cataloginfo
-    
-        
+
+
 def _unsigned(i):
     """Translate a signed int into an unsigned int.  Int type returned
     is longer than the original since Python has no unsigned int."""
@@ -1423,9 +1414,9 @@ def getLSInstalledApplications():
             applist.append(app_path)
 
     return applist
-    
+
 # we save APPDATA in a global to avoid querying LaunchServices more than
-# once per session    
+# once per session
 APPDATA = []
 def getAppData():
     """Gets info on currently installed apps.
@@ -1455,43 +1446,6 @@ def getAppData():
 # some utility functions
 
 
-def verifyFileOnlyWritableByMunkiAndRoot(file_path):
-    """
-    Check the permissions on a given file path; fail if owner or group
-    does not match the munki process (default: root/admin) or the group is not
-    'wheel', or if other users are able to write to the file. This prevents
-    escalated execution of arbitrary code.
-
-    Args:
-      file_path: str path of file to verify permissions on.
-    Raises:
-      VerifyFilePermissionsError: there was an error verifying file permissions.
-      InsecureFilePermissionsError: file permissions were found to be insecure.
-    """
-    try:
-        file_stat = os.stat(file_path)
-    except OSError, e:
-        raise VerifyFilePermissionsError(
-            '%s does not exist. \n %s' % (file_path, str(e)))
-
-    try:
-        # verify the munki process uid matches the file owner uid.
-        if os.geteuid() != file_stat.st_uid:
-            raise InsecureFilePermissionsError(
-                'owner does not match munki process!')
-        # verify the munki process gid matches the file owner gid, or the file
-        # owner gid is 80 (which is the admin group root is a member of).
-        elif os.getegid() != file_stat.st_gid and file_stat.st_gid != 80:
-            raise InsecureFilePermissionsError(
-                'group does not match munki process!')
-        # verify other users cannot write to the file.
-        elif file_stat.st_mode & stat.S_IWOTH != 0:
-            raise InsecureFilePermissionsError('world writable!')
-    except InsecureFilePermissionsError, e:
-        raise InsecureFilePermissionsError(
-            '%s is not secure! %s' % (file_path, e.args[0]))
-
-
 def getAvailableDiskSpace(volumepath='/'):
     """Returns available diskspace in KBytes."""
     cmd = ['/usr/sbin/diskutil', 'info', '-plist', volumepath]