openarc - ARC signing and verifying filter for MTAs
openarc [-c configfile] [-f] [-n] [-p socketspec] [-P pidfile] [-u
userid[:group]] [-v] [-V]
openarc implements the proposed ARC (Authenticated Received Chain)
standard for confirming handling and authentication of a message as it is
handled for delivery.
openarc uses the milter interface, originally
distributed as part of version 8.11 of sendmail(8), to provide ARC
signing and/or verifying service for mail transiting a milter-aware MTA.
- -c configfile
- Read the named configuration file. See the openarc.conf(5) man page
for details. Values in the configuration file are overridden when their
equivalents are provided on the command line until a configuration reload
occurs. The default is to read a configuration file from
/usr/local/etc/openarc.conf if one exists, or otherwise to apply
defaults to all values.
- -f
- Normally openarc forks and exits immediately, leaving the service
running in the background. This flag suppresses that behaviour so that it
runs in the foreground.
- -n
- Parse the configuration file and command line arguments, reporting any
errors found, and then exit. The exit value will be 0 if the filter would
start up without complaint, or non-zero otherwise.
- -p socketspec
- Specifies the socket that should be established by the filter to receive
connections from sendmail(8) 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 using the requested 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. If neither socket type is specified,
local is assumed, meaning the parameter is interpreted as a path at
which the socket should be created. This parameter is mandatory either
here or in the configuration file.
- -P pidfile
- Specifies a file into which the filter should write its process ID at
startup.
- -u userid[:group]
- Attempts to be come the specified userid before starting
operations. The process will be assigned all of the groups and primary
group ID of the named userid unless an alternate group is
specified. See the FILE PERMISSIONS section for more information.
- -V
- Print the version number and build-time options, and then exit without
doing anything else.
Filter exit status codes are selected according to sysexits(3).
This man page covers version 1.0.0 of openarc.
Copyright (c) 2005-2008, Sendmail, Inc. and its suppliers. All rights reserved.
Copyright (c) 2009-2013, 2015, 2016, The Trusted Domain Project.
All rights reserved.
openarc.conf(5), sendmail(8)
Sendmail Operations Guide
RFC5321 - Simple Mail Transfer Protocol
RFC5322 - Internet Messages
RFC7601 - Message Header Field for Indicating Message
Authentication Status