dkimpy-milter - Python milter for DKIM signing and validation
dkimpy-milter(8) implements the DKIM specification
for signing and verifying e-mail messages on a per-domain basis. This file
is its configuration file.
Blank lines are ignored. Lines containing a hash ("#")
character are truncated at the hash character to allow for comments in the
file.
Other content should be the name of a parameter, followed by white
space, followed by the value of that parameter, each on a separate line.
For parameters that are Boolean in nature, only the first byte of
the value is processed. For positive values, the following are accepted:
"T", "t", "Y", "y", "1".
For negative values, the following are accepted: "F",
"f", "N", "n", "0".
The provided setup.py installs this configuration file in /etc or
/usr/local/etc.
Command line invocation of parameters as is done by OpenDKIM is
not supported.
Usage:
dkimpy-milter [/etc/dkimpy-milter.conf]
This documentation assumes you have read Postfix's
README_FILES/MILTER_README (or Sendmail equivalent) and are generally
familiar with Domain Keys Identified Mail (DKIM). See RFC 6376 for
details.
dkimpy-milter operates with a default installed configuration file
and set of default configuration options that are used if the configuration
file cannot be found. These options can be changed by changing the installed
configuration files. For users transitioning from OpenDKIM, OpenDKIM config
files can be used directly. Not all OpenDKIM options are supported. If an
unsupported option from OpenDKIM is specified, an error will be raised.
Configuration options are described here and in the configuration
file provided with the package. The provided setup.py installs this
configuration file in /etc or /usr/local/etc.
- AuthservID
(string)
- Sets the "authserv-id" to use when generating the
Authentication-Results: header field after verifying a message. The
default is to use the name of the MTA processing the message. If the
string "HOSTNAME" is provided, the name of the host running the
filter (as returned by the gethostname(3) function) will be used.
- Canonicalization
(string)
- Selects the canonicalization method(s) to be used when signing messages.
When verifying, the message's DKIM-Signature: header field specifies the
canonicalization method. The recognized values are relaxed and
simple as defined by the DKIM specification. The default is
relaxed / simple. The value may include two different
canonicalizations separated by a slash ("/") character, in which
case the first will be applied to the header and the second to the body.
- DiagnosticDirectory
(string)
- Directory into which to write diagnostic reports when message verification
fails. If not set (the default), these files are not generated. [Unlike
OpenDKIM, this applies to all messages, not just on messages bearing a
"z=" tag because dkimpy does not yet support "z=".]
- Domain
(dataset)
- A set of domains whose mail should be signed by this filter. Mail from
other domains will be verified rather than being signed.
This parameter is not required if a SigningTable is in
use; in that case, the list of signed domains is implied by the lines in
that file. [SigningTable NOT IMPLEMENTED]
This parameter is ignored if a KeyTable is defined.
[KeyTable NOT IMPLEMENTED]
- InternalHosts
(dataset)
- Identifies a set internal hosts whose mail should be signed rather than
verified. Entries in this data set follow the same form as those of the
PeerList option below. If not specified, the default of
"127.0.0.1" is applied. Naturally, providing a value here
overrides the default, so if mail from 127.0.0.1 should be signed, the
list provided here should include that address explicitly. [PeerList NOT
IMPLEMENTED]
- KeyFile
(string)
- Gives the location of a PEM-formatted private key to be used for RSA
signing all messages. Ignored if a KeyTable is defined. [KeyTable
NOT IMPLEMENTED]
- KeyFileEd25519
(string)
- Gives the location of a Ed25519 private key to be used for Ed25519 signing
all messages. File is the Base64 encoded output of RFC 8032 Ed25519
private Key generation (as used in dkimpy). Ignored if a
KeyTableEd25519 is defined. [KeyTableEd25519 NOT IMPLEMENTED]
- MacroList
(dataset)
- Defines a set of MTA-provided macros that should be checked to see
if the sender has been determined to be a local user and therefore whether
or not the message should be signed. If a value is specified
matching a macro name in the data set, the value of the macro must match a
value specified (matching is case-sensitive), otherwise the macro must be
defined but may contain any value. The set is empty by default, meaning
macros are not considered when making the sign-verify decision. The
general format of the value is value1[|value2[|...]]; if one or
more value is defined then the macro must be set to one of the listed
values, otherwise the macro must be set but can contain any value.
In order for the macro and its value to be available to the
filter for checking, the MTA must send it during the protocol exchange.
This is either accomplished via manual configuration of the MTA to send
the desired macros or, for MTA/filter combinations that support the
feature, the filter can request those macros that are of interest. The
latter is a feature negotiated at the time the filter receives a
connection from the MTA and its availability depends upon the version of
milter used to compile the filter and the version of the MTA making the
connection.
- MacroListVerify
(dataset)
- Defines a set of MTA-provided macros that should be checked to see
if the sender has been determined to be an external source and therefore
whether or not the message should be signed. Entries in this data set
follow the same form as those of the MacroList option above. [this
option is not inhereted from OpenDKIM]
- Mode (string)
- Selects operating modes. The string is a concatenation of characters that
indicate which mode(s) of operation are desired. Valid modes are s
(signer) and v (verifier). The default is sv except in test
mode (see the opendkim(8) man page) in which case the default is
v. When signing mode is enabled, one of the following combinations
must also be set: (a) Domain, KeyFile, Selector, no KeyTable, no
SigningTable; (b) KeyTable, SigningTable, no Domain, no KeyFile, no
Selector; [fooTable options NOT IMPLEMENTED]
- PeerList
(dataset)
- Identifies a set of "peers" that identifies clients whose
connections should be accepted without processing by this filter. The set
should contain on each line a hostname, domain name (e.g.
".example.com"), IP address, an IPv6 address (including an IPv4
mapped address), or a CIDR-style IP specification (e.g.
"192.168.1.0/24"). An entry beginning with a bang
("!") character means "not", allowing exclusions of
specific hosts that are otherwise members of larger sets. Host and domain
names are matched first, then the IP or IPv6 address depending on the
connection type. More precise entries are preferred over less precise
ones, i.e. "192.168.1.1" will match before
"!192.168.1.0/24". The text form of IPv6 addresses will be
forced to lowercase when queried (RFC5952), so the contents of this data
set should also use lowercase. The IP address portion of an entry may
optionally contain square brackets; both forms (with and without) will be
checked. [PeerList NOT IMPLEMENTED - included for reference only]
- PidFile
(string)
- Specifies the path to a file that should be created at process start
containing the process ID.
- Selector
(string)
- Defines the name of the selector to be used when signing messages using
RSA. See the DKIM specification for details. Used only when signing
with a single key; see the SigningTable parameter below for more
information.
This parameter is ignored if a KeyTable is defined.
[KeyTable NOT IMPLEMENTED]
- SelectorEd25519
(string)
- Defines the name of the selector to be used when signing messages using
Ed25519. See the DKIM specification for details. Used only when
signing with a single key; see the SigningTable parameter below for
more information.
This parameter is ignored if a KeyTableEd25519 is
defined. [KeyTable NOT IMPLEMENTED]
- Socket
(string)
- Specifies the socket that should be established by the filter to receive
connections from postfix(1) in order to provide service.
socketspec is in one of two forms: local:path, which creates
a UNIX domain socket at the specified path, or
inet:port[@host] or inet6:port[@host] which creates a TCP
socket on the specified port and in the specified protocol family.
If the host is not given as either a hostname or an IP address, the
socket will be listening on all interfaces. A literal IP address must be
enclosed in square brackets. This option is mandatory in the configuration
file.
- Syslog
(Boolean)
- Log via calls to syslog(3) any interesting activity.
- SyslogFacility
(string)
- Log via calls to syslog(3) using the named facility. The facility
names are the same as the ones allowed in syslog.conf(5). The
default is "mail".
- SyslogSuccess
(Boolean)
- Log via calls to syslog(3) additional entries indicating successful
signing or verification of messages.
- UMask
(integer)
- Requests a specific permissions mask to be used for file creation. This
only really applies to creation of the socket when Socket specifies
a UNIX domain socket, and to the PidFile (if any); temporary files
are created by the mkstemp(3) function that enforces a specific
file mode on creation regardless of the process umask. See umask(2)
for more information.
- UserID
(string)
- Attempts to become the specified userid before starting operations. The
value is of the form userid[:group]. The process will be assigned
all of the groups and primary group ID of the named userid unless
an alternate group is specified.
dkimpy-milter was written by Scott Kitterman
<scott@kitterman.com>. It is based on dkimpy-milter.py Copyright (c)
2001-2013 Business Management Systems, Inc. Copyright (c) 2013-2015 Stuart
D. Gathman Copyright (c) 2018 Scott Kitterman
<scott@kitterman.com>.
This man-page was created by Scott Kitterman
<scott@kitterman.com>.
Configuration items derived from OpenDKIM 2.11.0
opendkim.conf.5.in: Copyright (c) 2007, 2008, Sendmail, Inc. and its
suppliers. All rights reserved. See LICENSE.Sendmail.
Copyright (c) 2009-2015, The Trusted Domain Project. All rights
reserved. See LICENSE.
Updated for dkimpy-milter. Updates licensed under the same terms
as the rest of the package. Copyright (c) 2018, Scott Kitterman
<scott@kitterman.com>