- Fold added authres header fields

- Fix pidfile permissions
 - Fix socket setup sequence so Unix sockets work

CHANGES

@@ -1,11 +1,11 @@
-
-0.9.1 2018-02-17
- - DKIM signing and verification using both RSA and Ed25519
- - The following configuration options are supported (same definition as
-   OpenDKIM): Domain, KeyFile, KeyFileEd25519, Mode, PidFile, Selector,
-   Socket, Syslog, UMask, and UserID (see dkimpy-milter.conf.5)
- - This is an Alpha grade release and while the implemented features work, it
-   is nowhere near being a complete package
+0.9.3 2018-03-02
+ - Fixup csl dataset processing for single item lists
+ - file: dataset support
+ - Bump minimum authres version to 1.1.0 due to known issues with 1.0.2
+ - Ignore errors parsing broken authres header fields
+ - Fold added authres header fields
+ - Fix pidfile permissions
+ - Fix socket setup sequence so Unix sockets work
 
 0.9.2 2018-02-19
  - Improved package requirements definition
@@ -16,3 +16,12 @@
  - Initial dataset support: csl
  - Only sign if mail from from a domain in Domain and only if Mode is not
    verfication only
+   
+0.9.1 2018-02-17
+ - DKIM signing and verification using both RSA and Ed25519
+ - The following configuration options are supported (same definition as
+   OpenDKIM): Domain, KeyFile, KeyFileEd25519, Mode, PidFile, Selector,
+   Socket, Syslog, UMask, and UserID (see dkimpy-milter.conf.5)
+ - This is an Alpha grade release and while the implemented features work, it
+   is nowhere near being a complete package
+

README

@@ -13,6 +13,19 @@ default is a feature:
 
 python setup.py install --single-version-externally-managed --record=/dev/null
 
+For users of Debian Stable (Debian 9, Codename Squueze), all dependencies are
+available in either the main or backports repositories:
+
+[sudo] apt install python-milter python-nacl
+[sudo] apt install -t squeeze-backports python-authres python-dkim
+
+The preferred method of installation is from PyPi using pip:
+
+[sudo] pip install dkimpy_milter
+
+Using pip will cause required packages to be installed via easy_install if they
+have not been previously installed.
+
 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

dkimpy_milter/__init__.py

@@ -39,8 +39,9 @@ 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
 
-__version__ = "0.9.2"
+__version__ = "0.9.3"
 FWS = re.compile(r'\r?\n[ \t]+')
   
 class dkimMilter(Milter.Base):
@@ -148,11 +149,15 @@ class dkimMilter(Milter.Base):
     # Remove existing Authentication-Results headers for our authserv_id
     for i,val in enumerate(self.arheaders,1):
       # FIXME: don't delete A-R headers from trusted MTAs
+      try:
           ar = authres.AuthenticationResultsHeader.parse_value(FWS.sub('',val))
           if ar.authserv_id == self.receiver:
               self.chgheader('authentication-results',i,'')
               if milterconfig.get('Syslog'):
                   syslog.syslog('REMOVE: {0}'.format(val))
+      except:
+          # Don't error out on unparseable AR header fiels
+          pass
     # Check or sign DKIM
     self.fp.seek(0)
     if (self.fdomain in milterconfig.get('Domain')) and (not milterconfig.get('Mode') == 'v'):
@@ -167,6 +172,7 @@ class dkimMilter(Milter.Base):
     if self.arresults:
         h = authres.AuthenticationResultsHeader(authserv_id = self.receiver, 
             results=self.arresults)
+        h = dkim.fold(str(h))
         if milterconfig.get('Syslog'):
             syslog.syslog(str(h))
         name,val = str(h).split(': ',1)
@@ -269,15 +275,16 @@ def main():
         privateRSA = read_keyfile(milterconfig, 'RSA')
     if milterconfig.get('KeyFileEd25519'):
         privateEd25519 = read_keyfile(milterconfig, 'Ed25519')
-    drop_privileges(milterconfig)
-    if milterconfig.get('Syslog'):
-        syslog.syslog('dkimpy-milter started:{0} user:{1}'.format(pid,milterconfig.get('UserID')))
     Milter.factory = dkimMilter
     Milter.set_flags(Milter.CHGHDRS + Milter.ADDHDRS)
     miltername = 'dkimpy-filter'
     socketname = milterconfig.get('Socket')
+    if milterconfig.get('Syslog'):
+        syslog.syslog('dkimpy-milter started:{0} user:{1}'.format(pid,milterconfig.get('UserID')))
     sys.stdout.flush()
     Milter.runmilter(miltername,socketname,240)
+    own_socketfile(milterconfig)
+    drop_privileges(milterconfig)
 
 if __name__ == "__main__":
     main()

dkimpy_milter/config.py

@@ -87,16 +87,39 @@ def _find_boolean(item):
 def _dataset_to_list(dataset):
     """Convert a dataset (as defined in dkimpymilter.8) and return a python
        list of values."""
-    if not isinstance(dataset, basestring):
-        # If it was a csl, it's already a list, we only need to remove the name
-        # from the first value
+    if not isinstance(dataset, str):
+        # If it was a csl with more than one value, it's already a list, we
+        # only need to remove the name from the first value.
         if dataset[0][:4] == 'csl:':
             dataset[0] = dataset[0][4:]
         for item in dataset:
             dataset[dataset.index(item)] = item.strip().strip(',')
         return dataset
+    elif isinstance(dataset, str):
+        if dataset[0] == '/' or dataset[:5] == 'file:':
+            # This is a flat file dataset
+            ds = []
+            if dataset[0] == '/':
+                dsname = dataset
+            if dataset[:5] == 'file:':
+                dsname = dataset[5:]
+            dsf = open(dsname, 'r')
+            for line in dsf.readlines():
+                if line[0] != '#':
+                    if len(line.split(':')) == 1:
+                        ds.append(line.strip())
                     else:
-        raise dkim.ParameterError('Unimplmented dataset type')
+                        for element in line.split(':'):
+                            ds.append(element.strip().strip(':'))
+            dsf.close()
+            return ds
+        # If it's a str and csl, it has one value and we return a list
+        if dataset[:4] == 'csl:':
+            return [dataset[4:].strip().strip(',')]
+        else:
+            return [dataset.strip().strip(',')]
+            
+    raise dkim.ParameterError('Unimplmented dataset type: {0}'.format(type(dataset)))
 
 ###############################################################
 commentRx = re.compile(r'^(.*)#.*$')

dkimpy_milter/util.py

@@ -16,10 +16,23 @@
 # with this program; if not, write to the Free Software Foundation, Inc.,
 # 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 
-def drop_privileges(milterconfig):
-    import os
+def user_group(userid):
+    """Return user and group from UserID"""
     import grp
     import pwd
+
+    userlist = userid.split(':')
+    if len(userlist) == 1:
+        gidname = userlist[0]
+    else:
+        gidname = userlist[1]
+    # Get the uid/gid from the name
+    running_uid = pwd.getpwnam(userlist[0]).pw_uid
+    running_gid = grp.getgrnam(gidname).gr_gid
+    return running_uid, running_gid
+
+def drop_privileges(milterconfig):
+    import os
     import syslog
 
     if os.getuid() != 0:
@@ -27,25 +40,15 @@ def drop_privileges(milterconfig):
             syslog.syslog('drop_privileges: Not running as root. Cannot drop permissions.')
         return
 
-    # Figure out if user and group are specified
-    userstr = milterconfig.get('UserID')
-    userlist = userstr.split(':')
-    if len(userlist) == 1:
-        gidname = userlist[0]
-    else:
-        gidname = userlist[1]
-    uidname = userlist[0]
-
-    # Get the uid/gid from the name
-    running_uid = pwd.getpwnam(uidname).pw_uid
-    running_gid = grp.getgrnam(gidname).gr_gid
+    # Get user and group
+    uid, gid = user_group(milterconfig.get('UserID'))
 
     # Remove group privileges
     os.setgroups([])
 
     # Try setting the new uid/gid
-    os.setgid(running_gid)
-    os.setuid(running_uid)
+    os.setgid(gid)
+    os.setuid(uid)
 
     # Set umask
     old_umask = os.umask(milterconfig.get('UMask'))
@@ -88,12 +91,23 @@ def write_pid(milterconfig):
             raise
         f.write(pid)
         f.close()
+        user, group = user_group(milterconfig.get('UserID'))
+        os.chown(milterconfig.get('PidFile'), user, group)
     else:
         if milterconfig.get('Syslog'):
             syslog.syslog('Unable to write pidfle {0}.  File exists.'.format(milterconfig.get('PidFile')))
         raise RuntimeError('Unable to write pidfle {0}.  File exists.'.format(milterconfig.get('PidFile')))
     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."""

etc/dkimpy-milter.conf

@@ -11,9 +11,9 @@ UMask			007
 
 # Sign for example.com with key in /etc/dkimkeys/dkim.key using
 # selector '2007' (e.g. 2007._domainkey.example.com)
-Domain			example.com
-KeyFile			/etc/mail/dkim.key
-Selector		default
+#Domain			example.com
+#KeyFile			/etc/mail/dkim.key
+#Selector		default
 
 # Commonly-used options; the commented-out versions show the defaults.
 #Canonicalization	relaxed/simple

setup.py

@@ -55,6 +55,6 @@ setup(
         (os.path.join('/lib', 'systemd', 'system'),
         ['system/dkimpy-milter.service']),(os.path.join('/etc', 'init.d'),
         ['system/dkimpy-milter'])],
-    install_requires = ['dkimpy>=0.7', 'pymilter', 'authres>=1.0.2', 'PyNaCl'],
+    install_requires = ['dkimpy>=0.7', 'pymilter', 'authres>=1.1.0', 'PyNaCl'],
     zip_safe = False,
 )