1 .\"	$OpenBSD$
2 .\"
3 .\" Copyright (c) 2019 Martijn van Duren <martijn@openbsd.org>
4 .\"
5 .\" Permission to use, copy, modify, and distribute this software for any
6 .\" purpose with or without fee is hereby granted, provided that the above
7 .\" copyright notice and this permission notice appear in all copies.
8 .\"
9 .\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10 .\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11 .\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12 .\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13 .\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14 .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15 .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16 .\"
17 .Dd $Mdocdate$
18 .Dt FILTER-DKIMSIGN 8
19 .Os
20 .Sh NAME
21 .Nm filter-dkimsign
22 .Nd add dkim signature to messages
23 .Sh SYNOPSIS
24 .Nm
25 .Op Fl tz
26 .Op Fl a Ar algorithm
27 .Op Fl c Ar canonicalization
28 .Op Fl h Ar headers
29 .Op Fl x Ar seconds
30 .Fl d Ar domain
31 .Fl k Ar file
32 .Fl s Ar selector
33 .Sh DESCRIPTION
34 .Nm
35 adds a dkim signature to the message.
36 The following flags are supported:
37 .Bl -tag -width Ds
38 .It Fl a Ar algorithm
39 The algorithm to use.
40 This implementation only supports rsa cryptography.
41 Only sha256 should be used for hashing, since other algorithms are most likely
42 not supported by verifiers.
43 Defaults to
44 .Ar rsa-sha256 .
45 .It Fl c Ar canonicalization
46 The canonicalization algorithm used to sign the messge.
47 Defaults to
48 .Ar simple/simple .
49 .It Fl d Ar domain
50 The domain where the public key can be found.
51 .It Fl h Ar headers
52 The email headers which are included in the mail signature.
53 Per RFC this option requires at least the from header to be included.
54 The headers are specified by separating them with a colon.
55 The default is
56 from:reply-to:subject:date:to:cc:resent-date:resent-from:resent-to:resent-cc:in-reply-to:references:list-id:list-help:list-unsubscribe:list-subscribe:list-post:list-owner:list-archive .
57 .It Fl k Ar file
58 .Ar file
59 should point to a file containing the RSA private key to sign the messages.
60 .It Fl s Ar selector
61 The selector within the _domainkey subdomain of
62 .Ar domain
63 where the public key can be found.
64 .It Fl t
65 Add the time of signing to the dkim header.
66 .It Fl x Ar seconds
67 Add the amount of
68 .Ar seconds
69 the signature is valid to the dkim header.
70 .It Fl z
71 Add the mail headers used in the dkim signature to the dkim header.
72 If a second
73 .Fl z
74 is specified all headers will be included in the dkim header.
75 Useful for debugging purposes.
76 .El
77 .Sh SEE ALSO
78 .Xr smtpd 8