Scott Kitterman
295 lines
9.7 KiB
Plaintext
295 lines
9.7 KiB
Plaintext
\"
|
|
.\" Standard preamble:
|
|
.\" ========================================================================
|
|
.de Sh \" Subsection heading
|
|
.br
|
|
.if t .Sp
|
|
.ne 5
|
|
.PP
|
|
\fB\\$1\fR
|
|
.PP
|
|
..
|
|
.de Sp \" Vertical space (when we can't use .PP)
|
|
.if t .sp .5v
|
|
.if n .sp
|
|
..
|
|
.de Vb \" Begin verbatim text
|
|
.ft CW
|
|
.nf
|
|
.ne \\$1
|
|
..
|
|
.de Ve \" End verbatim text
|
|
.ft R
|
|
.fi
|
|
..
|
|
.\" Set up some character translations and predefined strings. \*(-- will
|
|
.\" give an unbreakable dash, \*(PI will give pi, \*(L" will give a left
|
|
.\" double quote, and \*(R" will give a right double quote. \*(C+ will
|
|
.\" give a nicer C++. Capital omega is used to do unbreakable dashes and
|
|
.\" therefore won't be available. \*(C` and \*(C' expand to `' in nroff,
|
|
.\" nothing in troff, for use with C<>.
|
|
.tr \(*W-
|
|
.ds C+ C\v'-.1v'\h'-1p'\s-2+\h'-1p'+\s0\v'.1v'\h'-1p'
|
|
.ie n \{\
|
|
. ds -- \(*W-
|
|
. ds PI pi
|
|
. if (\n(.H=4u)&(1m=24u) .ds -- \(*W\h'-12u'\(*W\h'-12u'-\" diablo 10 pitch
|
|
. if (\n(.H=4u)&(1m=20u) .ds -- \(*W\h'-12u'\(*W\h'-8u'-\" diablo 12 pitch
|
|
. ds L" ""
|
|
. ds R" ""
|
|
. ds C` ""
|
|
. ds C' ""
|
|
'br\}
|
|
.el\{\
|
|
. ds -- \|\(em\|
|
|
. ds PI \(*p
|
|
. ds L" ``
|
|
. ds R" ''
|
|
'br\}
|
|
.\"
|
|
.\" If the F register is turned on, we'll generate index entries on stderr for
|
|
.\" titles (.TH), headers (.SH), subsections (.Sh), items (.Ip), and index
|
|
.\" entries marked with X<> in POD. Of course, you'll have to process the
|
|
.\" output yourself in some meaningful fashion.
|
|
.if \nF \{\
|
|
. de IX
|
|
. tm Index:\\$1\t\\n%\t"\\$2"
|
|
..
|
|
. nr % 0
|
|
. rr F
|
|
.\}
|
|
.\"
|
|
.\" For nroff, turn off justification. Always turn off hyphenation; it makes
|
|
.\" way too many mistakes in technical documents.
|
|
.hy 0
|
|
.if n .na
|
|
.\"
|
|
.\" Accent mark definitions (@(#)ms.acc 1.5 88/02/08 SMI; from UCB 4.2).
|
|
.\" Fear. Run. Save yourself. No user-serviceable parts.
|
|
. \" fudge factors for nroff and troff
|
|
.if n \{\
|
|
. ds #H 0
|
|
. ds #V .8m
|
|
. ds #F .3m
|
|
. ds #[ \f1
|
|
. ds #] \fP
|
|
.\}
|
|
.if t \{\
|
|
. ds #H ((1u-(\\\\n(.fu%2u))*.13m)
|
|
. ds #V .6m
|
|
. ds #F 0
|
|
. ds #[ \&
|
|
. ds #] \&
|
|
.\}
|
|
. \" simple accents for nroff and troff
|
|
.if n \{\
|
|
. ds ' \&
|
|
. ds ` \&
|
|
. ds ^ \&
|
|
. ds , \&
|
|
. ds ~ ~
|
|
. ds /
|
|
.\}
|
|
.if t \{\
|
|
. ds ' \\k:\h'-(\\n(.wu*8/10-\*(#H)'\'\h"|\\n:u"
|
|
. ds ` \\k:\h'-(\\n(.wu*8/10-\*(#H)'\`\h'|\\n:u'
|
|
. ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'^\h'|\\n:u'
|
|
. ds , \\k:\h'-(\\n(.wu*8/10)',\h'|\\n:u'
|
|
. ds ~ \\k:\h'-(\\n(.wu-\*(#H-.1m)'~\h'|\\n:u'
|
|
. ds / \\k:\h'-(\\n(.wu*8/10-\*(#H)'\z\(sl\h'|\\n:u'
|
|
.\}
|
|
. \" troff and (daisy-wheel) nroff accents
|
|
.ds : \\k:\h'-(\\n(.wu*8/10-\*(#H+.1m+\*(#F)'\v'-\*(#V'\z.\h'.2m+\*(#F'.\h'|\\n:u'\v'\*(#V'
|
|
.ds 8 \h'\*(#H'\(*b\h'-\*(#H'
|
|
.ds o \\k:\h'-(\\n(.wu+\w'\(de'u-\*(#H)/2u'\v'-.3n'\*(#[\z\(de\v'.3n'\h'|\\n:u'\*(#]
|
|
.ds d- \h'\*(#H'\(pd\h'-\w'~'u'\v'-.25m'\f2\(hy\fP\v'.25m'\h'-\*(#H'
|
|
.ds D- D\\k:\h'-\w'D'u'\v'-.11m'\z\(hy\v'.11m'\h'|\\n:u'
|
|
.ds th \*(#[\v'.3m'\s+1I\s-1\v'-.3m'\h'-(\w'I'u*2/3)'\s-1o\s+1\*(#]
|
|
.ds Th \*(#[\s+2I\s-2\h'-\w'I'u*3/5'\v'-.3m'o\v'.3m'\*(#]
|
|
.ds ae a\h'-(\w'a'u*4/10)'e
|
|
.ds Ae A\h'-(\w'A'u*4/10)'E
|
|
. \" corrections for vroff
|
|
.if v .ds ~ \\k:\h'-(\\n(.wu*9/10-\*(#H)'\s-2\u~\d\s+2\h'|\\n:u'
|
|
.if v .ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'\v'-.4m'^\v'.4m'\h'|\\n:u'
|
|
. \" for low resolution devices (crt and lpr)
|
|
.if \n(.H>23 .if \n(.V>19 \
|
|
\{\
|
|
. ds : e
|
|
. ds 8 ss
|
|
. ds o a
|
|
. ds d- d\h'-1'\(ga
|
|
. ds D- D\h'-1'\(hy
|
|
. ds th \o'bp'
|
|
. ds Th \o'LP'
|
|
. ds ae ae
|
|
. ds Ae AE
|
|
.\}
|
|
.rm #[ #] #H #V #F C
|
|
.\" ========================================================================
|
|
.\"
|
|
.TH dkimpyy-milter 8
|
|
.SH NAME
|
|
.B dkimpy
|
|
\- DKIM signing and verifying filter for MTAs
|
|
.SH SYNOPSIS
|
|
.B dkimpy-milter [configfile]
|
|
|
|
.SH DESCRIPTION
|
|
.B dkimpy-milter
|
|
implements the
|
|
.B DKIM
|
|
standard for signing and verifying e-mail messages on a per-domain basis.
|
|
|
|
.B dkimpy-milter
|
|
uses the
|
|
.I milter
|
|
interface, originally distributed as part of version 8.11 of
|
|
.B sendmail(8),
|
|
to provide DKIM signing and/or verifying service for mail transiting
|
|
a milter-aware MTA.
|
|
|
|
.SH DATA SETS
|
|
Many of the configuration file parameters will refer to a "dataset" as their
|
|
values. This refers to a string that either contains the list of desirable
|
|
values, or to a file that contains them, or a database containing the data.
|
|
|
|
Some data sets require that the value contain more than one entry. How this
|
|
is done depends on which data set type is used. Not all these datasets are
|
|
currently used by dkimpy-milter. See
|
|
.B dkimpy-milter.conf(5)
|
|
for details about specific options and which dataset types they use.
|
|
|
|
In particular:
|
|
.TP
|
|
.I a)
|
|
If the string begins with "file:", then the remainder of the string is
|
|
presumed to refer to a flat file that contains elements of the data set,
|
|
one per line. If a line contains whitespace-separated values, then the
|
|
line is presumed to define a key and its corresponding value. Blank lines
|
|
are ignored, and the hash ("#") character denotes the start of a comment.
|
|
If a value contains multiple entries, the entries should be separated by
|
|
colons.
|
|
.TP
|
|
.I b)
|
|
If the string begins with "refile:", then the remainder of the string is
|
|
presumed to specify a file that contains a set of patterns, one per line,
|
|
and their associated values. The pattern is taken as the start of the line
|
|
to the first whitespace, and the portion after that whitespace is taken as
|
|
the value to be used when that pattern is matched. Patterns are simple
|
|
wildcard patterns, matching all text except that the asterisk ("*") character
|
|
is considered a wildcard. If a value contains multiple entries, the entries
|
|
should be separated by colons.
|
|
.TP
|
|
.I i)
|
|
If the string contains none of these prefixes but starts with a slash ("/")
|
|
character, it is presumed to be a flat file as described above.
|
|
.TP
|
|
.I j)
|
|
If the string begins with "csl:", the string is treated as a comma-separated
|
|
list as described in m) below.
|
|
.TP
|
|
.I l)
|
|
If the string begins with "mdb:", it refers to a directory that contains
|
|
a memory database, as provided by libmdb from OpenLDAP. [Not implemented yet]
|
|
.TP
|
|
.I m)
|
|
In any other case, the string is presumed to be a comma-separated list.
|
|
Elements in the list are either simple data elements that are part of the
|
|
set or, in the case of an entry of the form "x=y", are stored as key-value
|
|
pairs as described above.
|
|
.SH OPTIONS
|
|
.TP
|
|
See
|
|
.I dkimpy-milter.conf(5)
|
|
information about available options. Unlike OpenDKIM, with the exception of
|
|
\-P for the pidfile and specifying the configuration file to use,
|
|
dkimpy-milter does not support command line option switches.
|
|
|
|
When signing a message, a
|
|
.I DKIM-Signature:
|
|
header will be prepended to the message. The signature is computed using
|
|
the private key provided. You must be running a version of
|
|
.I sendmail(8)
|
|
recent enough to be able to do header prepend operations (8.13.0 or later).
|
|
|
|
When verifying a message, an
|
|
.I Authentication-Results:
|
|
header will be prepended to indicate the presence of a signature and whether
|
|
or not it could be validated against the body of the message using the
|
|
public key advertised by the sender's nameserver. The value of this header
|
|
can be used by mail user agents to sort or discard messages that were not
|
|
signed or could not be verified.
|
|
|
|
.SH FILE PERMISSIONS
|
|
When the filter is started as the superuser and the UserID setting is
|
|
used, the filter gives up its root privileges by changing to the specified
|
|
user after the following steps are taken: (1) the configuration file (if any)
|
|
is loaded; (2) if the KeyFile or KeyFileEd25519 settings are used, the keys are
|
|
loaded into memory; (3) all data sets in the configuration file are opened, and
|
|
those that are based on flat files are also read into memory; and (4) if
|
|
ChangeRootDirectory is set, the process root is changed to that directory.
|
|
This means on configuration reload, the filter will not be accessing these
|
|
files or the configuration file as the superuser (and possibly from a
|
|
different root), and any key files referenced by the KeyTable will also be
|
|
accessed by the new user.
|
|
|
|
Thus, keys referenced by the KeyTable must always be accessible for read by
|
|
the unprivileged user. Also, run-time reloads are not possible if any of the
|
|
other files will not be readable by the unprivileged user.
|
|
.SH ENVIRONMENT
|
|
The following environment variable(s) can be used to adjust the behaviour
|
|
of this filter:
|
|
.TP
|
|
.I DKIM_TMPDIR
|
|
The directory to use when creating temporary files. The default is
|
|
.I /tmp.
|
|
.SH NOTES
|
|
When using DNS timeouts be sure not to use a timeout that is larger than the
|
|
timeout being used for interaction between
|
|
.I sendmail
|
|
and the filter. Otherwise, the MTA could abort a message while waiting for
|
|
a reply from the filter, which in turn is still waiting for a DNS reply.
|
|
|
|
Features that involve specification of IPv4 addresses or CIDR blocks
|
|
will use the
|
|
.I inet_addr(3)
|
|
function to parse that information. Users should be familiar with the
|
|
way that function handles the non-trivial cases (for example, "192.0.2/24"
|
|
and "192.0.2.0/24" are not the same thing).
|
|
.SH EXIT STATUS
|
|
Filter exit status codes are selected according to
|
|
.I sysexits(3).
|
|
.SH HISTORY
|
|
DKIM is an amalgam of Yahoo!'s
|
|
.B DomainKeys
|
|
proposal, and Cisco's
|
|
.B Internet Identified Mail
|
|
(IIM) proposal.
|
|
.SH VERSION
|
|
This man page covers version 1.1.0 of
|
|
.I dkimpy-milter.
|
|
.SH COPYRIGHT
|
|
Copyright (c) 2005-2008, Sendmail, Inc. and its suppliers. All rights
|
|
reserved.
|
|
|
|
Copyright (c) 2009-2013, 2015, The Trusted Domain Project.
|
|
All rights reserved.
|
|
|
|
Copyright (c) 2018, 2019 Scott Kitterman <scott@kitterman.com>
|
|
.SH SEE ALSO
|
|
.I dkimpy-milter.conf(5), sendmail(8)
|
|
.P
|
|
Sendmail Operations Guide
|
|
.P
|
|
RFC5321 - Simple Mail Transfer Protocol
|
|
.P
|
|
RFC5322 - Internet Messages
|
|
.P
|
|
RFC6376 - DomainKeys Identified Mail
|
|
.P
|
|
RFC7601 - Message Header Field for Indicating Message Authentication Status
|
|
.P
|
|
RFC8301 - Cryptographic Algorithm and Key Usage Update to DomainKeys Identified Mail (DKIM)
|
|
.P
|
|
RFC8463 - A New Cryptographic Signature Method for DomainKeys Identified Mail (DKIM)
|