Fix typo in log message

change fails on a Unix socket because it hasn't been created yet (libmilter
   will do this correctly on its own based on umask, the milter doesn't need
   to do it) (LP: #1849712)

CHANGES

@@ -1,3 +1,20 @@
+1.0.3 2019-11-22
+ - Make error logging more explicit to aid debugging
+ - Delete own_socketfile to resolve race condition where the permissions
+   change fails on a Unix socket because it hasn't been created yet (libmilter
+   will do this correctly on its own based on umask, the milter doesn't need
+   to do it) (LP: #1849712)
+
+1.0.2 2019-10-07
+ - Fix startup logging so it provides information at a useful time
+ - Fix message extraction so that signing in the same pass through the milter
+   as verifying works correctly
+ - Fix variable initialization so mailformed mails missing body From do not
+   cause a traceback (LP: #1844161)
+ - Catch more ascii encoding errors to improve resilience against bad data
+   (LP: #1844189)
+ - Fix sysv init so it works (LP: #1839487)
+
 1.0.1 2019-02-11
  * Reorder milter start and dropping privileges so permissions on Unix socket
    are correct (LP: 1797720)

README

@@ -37,7 +37,7 @@ an C compiler.  Alternately, install these dependencies from dsitribution/OS
 packages and then pip install dkimpy_milter.
 
 The milter will work with either pydns (DNS) or dnspython (dns), preferring
-dnspython is both are available.  The dkimpy DKIM module also works with
+dnspython if both are available.  The dkimpy DKIM module also works with
 either.
 
 
@@ -84,9 +84,8 @@ MTA INTEGRATION
 
 Both a systemd unit file and a sysv init file are provided.  Both make
 assumptions about defaults being used, e.g. if a non-standard pidfile name is
-used, they will need to be updated.  The sysv init file is Debian specific and
-untested, since the developers are not using sysv init.  Feedback/patches
-welcome.
+used, they will need to be updated.  The sysv init file uses start-stop-deamon
+from Debian.  It is not portable to systems without that available.
 
 The dkimpy-milter drops priviledges after setup to the user/group specified in
 UserID.  During initial setup, this system user needs to be manually created.

dkimpy_milter/__init__.py

@@ -36,7 +36,6 @@ from dkimpy_milter.util import drop_privileges
 from dkimpy_milter.util import setExceptHook
 from dkimpy_milter.util import write_pid
 from dkimpy_milter.util import read_keyfile
-from dkimpy_milter.util import own_socketfile
 from dkimpy_milter.util import fold
 
 __version__ = "1.0.1"
@@ -54,6 +53,7 @@ class dkimMilter(Milter.Base):
         self.privatersa = privateRSA
         self.privateed25519 = privateEd25519
         self.fp = None
+        self.fdomain = ''
 
     @Milter.noreply
     def connect(self, hostname, unused, hostaddr):
@@ -133,14 +133,18 @@ class dkimMilter(Milter.Base):
             try:
                 self.fdomain = self.author.split('@')[1].lower()
             except IndexError as er:
-                self.fdomain = ''  # self.author was not a proper email address
+                pass # self.author was not a proper email address
             if (milterconfig.get('Syslog') and
                     milterconfig.get('debugLevel') >= 1):
                 syslog.syslog("{0}: {1}".format(name, val))
         elif lname == 'authentication-results':
             self.arheaders.append(val)
         if self.fp:
-            self.fp.write("%s: %s\n" % (name, val))
+            try:
+                self.fp.write("%s: %s\n" % (name, val))
+            except:
+                # Don't choke on header fields with garbage in them.
+                pass
         return Milter.CONTINUE
 
     @Milter.noreply
@@ -174,20 +178,19 @@ class dkimMilter(Milter.Base):
             except:
                 # Don't error out on unparseable AR header fiels
                 pass
-        # Check or sign DKIM
+        # Check and/or sign DKIM
         self.fp.seek(0)
+        txt = self.fp.read()
         if milterconfig.get('Domain'):
             domain = milterconfig.get('Domain')
         else:
             domain = ''
         if ((self.fdomain in domain) and not milterconfig.get('Mode') == 'v'
                 and not self.external_connection):
-            txt = self.fp.read()
             self.sign_dkim(txt)
         if ((self.has_dkim) and (not self.internal_connection) and
             (milterconfig.get('Mode') == 'v' or
              milterconfig.get('Mode') == 'sv')):
-            txt = self.fp.read()
             self.check_dkim(txt)
         if self.arresults:
             h = authres.AuthenticationResultsHeader(authserv_id=
@@ -255,6 +258,7 @@ class dkimMilter(Milter.Base):
 
     def check_dkim(self, txt):
         res = False
+        self.header_a = None
         for y in range(self.has_dkim):  # Verify _ALL_ the signatures
             d = dkim.DKIM(txt)
             try:
@@ -280,10 +284,21 @@ class dkimMilter(Milter.Base):
             except Exception as x:
                 self.dkim_comment = str(x)
                 if milterconfig.get('Syslog'):
-                    syslog.syslog("check_dkim: {0}".format(x))
-            self.header_i = d.signature_fields.get(b'i')
-            self.header_d = d.signature_fields.get(b'd')
-            self.header_a = d.signature_fields.get(b'a')
+                    syslog.syslog("check_dkim: Internal program fault while verifying: {0}".format(x))
+            try:
+                self.header_i = d.signature_fields.get(b'i')
+            except TypeError as x:
+                self.header_i = None
+            try:
+                self.header_d = d.signature_fields.get(b'd')
+                self.header_a = d.signature_fields.get(b'a')
+            except Exception as x:
+                self.dkim_comment = str(x)
+                if milterconfig.get('Syslog'):
+                    syslog.syslog("check_dkim: Internal proram fault extracting header a or d: {0}".format(x))
+                self.header_d = None
+            if not self.header_a:
+                self.header_a = 'rsa-sha256'
             if res:
                 if (milterconfig.get('Syslog') and
                         (milterconfig.get('SyslogSuccess') or
@@ -303,20 +318,27 @@ class dkimMilter(Milter.Base):
                         syslog.syslog('DKIM: Fail (saved as {0})'
                                       .format(fname))
                 else:
-                    syslog.syslog('DKIM: Fail ({0})'.format(d.domain.lower()))
+                    if milterconfig.get('Syslog'):
+                        if d.domain:
+                            syslog.syslog('DKIM: Fail ({0})'
+                                          .format(d.domain.lower()))
+                        else:
+                            syslog.syslog('DKIM: Fail, unextractable domain')
             if res:
                 result = 'pass'
             else:
                 result = 'fail'
             res = False
-            self.arresults.append(
-                authres.DKIMAuthenticationResult(result=result,
+            if self.header_d:
+                self.arresults.append(
+                    authres.DKIMAuthenticationResult(result=result,
                                                  header_i=self.header_i,
                                                  header_d=self.header_d,
                                                  header_a=self.header_a,
                                                  result_comment=
                                                  self.dkim_comment)
             )
+            self.header_a = None
         return
 
 
@@ -348,13 +370,12 @@ def main():
     Milter.set_flags(Milter.CHGHDRS + Milter.ADDHDRS)
     miltername = 'dkimpy-filter'
     socketname = milterconfig.get('Socket')
-    own_socketfile(milterconfig)
     drop_privileges(milterconfig)
     sys.stdout.flush()
-    Milter.runmilter(miltername, socketname, 240)
     if milterconfig.get('Syslog'):
-        syslog.syslog('dkimpy-milter started:{0} user:{1}'
+        syslog.syslog('dkimpy-milter starting:{0} user:{1}'
                       .format(pid, milterconfig.get('UserID')))
+    Milter.runmilter(miltername, socketname, 240)
 
 if __name__ == "__main__":
     main()

dkimpy_milter/util.py

@@ -146,16 +146,6 @@ def write_pid(milterconfig):
     return pid
 
 
-def own_socketfile(milterconfig):
-    """If socket is Unix socket, chown to UserID before dropping privileges"""
-    import os
-    user, group = user_group(milterconfig.get('UserID'))
-    if milterconfig.get('Socket')[:1] == '/':
-        os.chown(milterconfig.get('Socket')[1:], user, group)
-    if milterconfig.get('Socket')[:6] == "local:":
-        os.chown(milterconfig.get('Socket')[6:], user, group)
-
-
 def read_keyfile(milterconfig, keytype):
     """Read private key from file."""
     import syslog

setup.py

@@ -30,7 +30,7 @@ except ImportError:  # If PyDNS is not installed, prefer dnspython
 
 setup(
     name='dkimpy-milter',
-    version='1.0.1',
+    version='1.0.3',
     author='Scott Kitterman',
     author_email='scott@kitterman.com',
     url='https://launchpad.net/dkimpy-milter',

system/dkimpy-milter

@@ -20,9 +20,9 @@
 ### END INIT INFO
 prefix="/usr/local"
 exec_prefix=${prefix}
-sysconfdir="/etc/dkimpy-milter"
+sysconfdir="/usr/local/etc"
 bindir="${exec_prefix}/bin/"
-RUNDIR="/var/run/dkimpy-milter"
+RUNDIR="/run/dkimpy-milter"
 DAEMON=${bindir}/dkimpy-milter
 PATH=/sbin:/bin:/usr/sbin:/usr/bin:/usr/local/bin:
 NAME=dkimpy-milter
@@ -67,14 +67,14 @@ case "$1" in
 			fi
 		fi
 	fi
-
-        start-stop-daemon --start --quiet --pidfile $RUNDIR/$NAME.pid --startas \
-                $DAEMON $sysconfdir/$NAME.conf --name $NAME --test > /dev/null \
+        start-stop-daemon --start --background --quiet --pidfile \
+                $RUNDIR/$NAME.pid --exec $DAEMON $sysconfdir/$NAME.conf
 	echo "$NAME."
 	;;
   stop)
 	echo -n "Stopping $DESC: "
 	if [ -f $RUNDIR/$NAME.pid ]; then
+		chown root:root $RUNDIR/$NAME.pid
 		start-stop-daemon --stop --pidfile $RUNDIR/$NAME.pid 
 		rm $RUNDIR/$NAME.pid
 		#echo $SOCKET
@@ -87,6 +87,7 @@ case "$1" in
   force-reload)
         echo -n "Force reloading $DESC: "
         if [ -f $RUNDIR/$NAME.pid ]; then
+                chown root:root $RUNDIR/$NAME.pid
                 start-stop-daemon --stop --pidfile $RUNDIR/$NAME.pid
                 rm $RUNDIR/$NAME.pid
                 #echo $SOCKET
@@ -95,7 +96,7 @@ case "$1" in
                 fi
         fi
         sleep 1
-        start-stop-daemon --start --chuid $USER --background --quiet --pidfile \
+        start-stop-daemon --start --background --quiet --pidfile \
                 $RUNDIR/$NAME.pid --exec $DAEMON $sysconfdir/$NAME.conf
         echo "$NAME."
         ;;
@@ -103,6 +104,7 @@ case "$1" in
         echo "Restarting $DESC: "
         echo -n "Stopping $DESC: "
         if [ -f $RUNDIR/$NAME.pid ]; then
+                chown root:root $RUNDIR/$NAME.pid
                 start-stop-daemon --stop --pidfile $RUNDIR/$NAME.pid
                 rm $RUNDIR/$NAME.pid
                 #echo $SOCKET
@@ -113,7 +115,7 @@ case "$1" in
         echo "$NAME."
 	sleep 1
         echo -n "Starting $DESC: "
-        start-stop-daemon --start --chuid $USER --background --quiet --pidfile \
+        start-stop-daemon --start --background --quiet --pidfile \
                 $RUNDIR/$NAME.pid --exec $DAEMON $sysconfdir/$NAME.conf
         echo "$NAME."
 	;;